Publications

Authors: Type:

2018

    [Bibtex]
    @ARTICLE {Furmanova2018COZOID,
    author = "Furmanov{\'a}, Katar{\'\i}na and By{\v{s}}ka, Jan and Gr{\"o}ller, Eduard M and Viola, Ivan and Pale{\v{c}}ek, Jan J and Kozl{\'i}kov{\'a}, Barbora",
    title = "COZOID: contact zone identifier for visual analysis of protein-protein interactions",
    journal = "BMC bioinformatics",
    year = "2018"
    }
    [YT] [Bibtex]
    @ARTICLE {lichtenbergsmithansenlawonn2018,
    author = "Nils Lichtenberg and Noeska Smit and Christian Hansen and Kai Lawonn",
    title = "Real-time field aligned stripe patterns",
    journal = "Computers & Graphics",
    year = "2018",
    volume = "74",
    pages = "137-149",
    month = "aug",
    abstract = "In this paper, we present a parameterization technique that can be applied to surface meshes in real-time without time-consuming preprocessing steps. The parameterization is suitable for the display of (un-)oriented patterns and texture patches, and to sample a surface in a periodic fashion. The method is inspired by existing work that solves a global optimization problem to generate a continuous stripe pattern on the surface, from which texture coordinates can be derived. We propose a local optimization approach that is suitable for parallel execution on the GPU, which drastically reduces computation time. With this, we achieve on-the-fly texturing of 3D, medium-sized (up to 70 k vertices) surface meshes. The algorithm takes a tangent vector field as input and aligns the texture coordinates to it. Our technique achieves real-time parameterization of the surface meshes by employing a parallelizable local search algorithm that converges to a local minimum in a few iterations. The calculation in real-time allows for live parameter updates and determination of varying texture coordinates. Furthermore, the method can handle non-manifold meshes. The technique is useful in various applications, e.g., biomedical visualization and flow visualization. We highlight our method’s potential by providing usage scenarios for several applications.",
    images = "images/Selection_384.png",
    thumbnails = "images/1-s2.0-S0097849318300591-fx1_lrg.jpg",
    youtube = "https://www.youtube.com/watch?v=7CpkHy8KPK8",
    project = "ttmedvis"
    }
    [PDF] [DOI] [Bibtex]
    @ARTICLE {10.1111:cgf.13405,
    author = "Fan, Chaoran and Hauser, Helwig",
    title = "{Fast and Accurate CNN-based Brushing in Scatterplots}",
    journal = "Computer Graphics Forum (Eurovis 2018)",
    year = "2018",
    abstract = "Brushing plays a central role in most modern visual analytics solutions and effective and efficient techniques for data selection are key to establishing a successful human-computer dialogue. With this paper, we address the need for brushing techniques that are both fast, enabling a fluid interaction in visual data exploration and analysis, and also accurate, i.e., enabling the user to effectively select specific data subsets, even when their geometric delimination is non-trivial. We present a new solution for a near-perfect sketch-based brushing technique, where we exploit a convolutional neural network (CNN) for estimating the intended data selection from a fast and simple click-and-drag interaction and from the data distribution in the visualization. Our key contributions include a drastically reduced error rate-now below 3%, i.e., less than half of the so far best accuracy- and an extension to a larger variety of selected data subsets, going beyond previous limitations due to linear estimation models.",
    pdf = "pdfs/eurovis18 (1).pdf",
    images = "images/cnn.png",
    thumbnails = "images/cnn.png",
    publisher = "The Eurographics Association and John Wiley & Sons Ltd.",
    issn = "1467-8659",
    doi = "10.1111/cgf.13405"
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Magnus-2018-VPI,
    author = {Jens G. Magnus and Stefan Bruckner},
    title = {Interactive Dynamic Volume Illumination with Refraction and Caustics},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2018},
    volume = {24},
    number = {1},
    pages = {984--993},
    month = jan,
    abstract = {In recent years, significant progress has been made in
    developing high-quality interactive methods for realistic volume
    illumination. However, refraction -- despite being an important aspect
    of light propagation in participating media -- has so far only received
    little attention. In this paper, we present a novel approach for
    refractive volume illumination including caustics capable of interactive
    frame rates. By interleaving light and viewing ray propagation, our
    technique avoids memory-intensive storage of illumination information
    and does not require any precomputation. It is fully dynamic and all
    parameters such as light position and transfer function can be modified
    interactively without a performance penalty.},
    doi = {10.1109/TVCG.2017.2744438},
    event = {IEEE SciVis 2017},
    images = {images/Magnus-2018-IDV.jpg},
    keywords = {interactive volume rendering, illumination, refraction, shadows, caustics},
    location = {Phoenix, USA},
    pdf = {pdfs/Magnus-2018-IDV.pdf},
    thumbnails = {images/Magnus-2018-IDV.png},
    youtube = {https://www.youtube.com/watch?v=3tn6sSXw4NQ},
    }

2017

    [PDF] [DOI] [Bibtex]
    @ARTICLE {Turkay2017VIS,
    author = "C. Turkay and E. Kaya and S. Balcisoy and H. Hauser",
    title = "Designing Progressive and Interactive Analytics Processes for High-Dimensional Data Analysis",
    journal = "IEEE Transactions on Visualization and Computer Graphics",
    year = "2017",
    volume = "PP",
    number = "99",
    pages = "1-1",
    month = "jan",
    abstract = "In interactive data analysis processes, the dialogue between the human and the computer is the enabling mechanism that can lead to actionable observations about the phenomena being investigated. It is of paramount importance that this dialogue is not interrupted by slow computational mechanisms that do not consider any known temporal human-computer interaction characteristics that prioritize the perceptual and cognitive capabilities of the users. In cases where the analysis involves an integrated computational method, for instance to reduce the dimensionality of the data or to perform clustering, such non-optimal processes are often likely. To remedy this, progressive computations, where results are iteratively improved, are getting increasing interest in visual analytics. In this paper, we present techniques and design considerations to incorporate progressive methods within interactive analysis processes that involve high-dimensional data. We define methodologies to facilitate processes that adhere to the perceptual characteristics of users and describe how online algorithms can be incorporated within these. A set of design recommendations and according methods to support analysts in accomplishing high-dimensional data analysis tasks are then presented. Our arguments and decisions here are informed by observations gathered over a series of analysis sessions with analysts from finance. We document observations and recommendations from this study and present evidence on how our approach contribute to the efficiency and productivity of interactive visual analysis sessions involving high-dimensional data.",
    pdf = "pdfs/2016-11-04--Turkay-2017-VIS.pdf",
    images = "images/Turkay-2017-VIS.png",
    thumbnails = "images/Turkay-2017-VIS.png",
    doi = "10.1109/TVCG.2016.2598470",
    issn = "1077-2626"
    }
    [PDF] [DOI] [Bibtex]
    @ARTICLE {LawonnSmit-2017-Survey,
    author = "Lawonn, K. and Smit, N.N. and B{\"u}hler, K. and Preim, B.",
    title = "A Survey on Multimodal Medical Data Visualization",
    journal = "Computer Graphics Forum",
    year = "2017",
    abstract = "Multi-modal data of the complex human anatomy contain a wealth of information. To visualize and explore such data, techniques for emphasizing important structures and controlling visibility are essential. Such fused overview visualizations guide physicians to suspicious regions to be analysed in detail, e.g. with slice-based viewing. We give an overview of state of the art in multi-modal medical data visualization techniques. Multi-modal medical data consist of multiple scans of the same subject using various acquisition methods, often combining multiple complimentary types of information. Three-dimensional visualization techniques for multi-modal medical data can be used in diagnosis, treatment planning, doctor–patient communication as well as interdisciplinary communication. Over the years, multiple techniques have been developed in order to cope with the various associated challenges and present the relevant information from multiple sources in an insightful way. We present an overview of these techniques and analyse the specific challenges that arise in multi-modal data visualization and how recent works aimed to solve these, often using smart visibility techniques. We provide a taxonomy of these multi-modal visualization applications based on the modalities used and the visualization techniques employed. Additionally, we identify unsolved problems as potential future research directions.",
    pdf = "pdfs/LawonnSmit-2017-MULTI.pdf",
    images = "images/LawonnSmit-2017-MULTI.jpg",
    thumbnails = "images/LawonnSmit-2017-MULTI-TN.png",
    note = "CGF Early View",
    issn = "1467-8659",
    url = "http://dx.doi.org/10.1111/cgf.13306",
    doi = "10.1111/cgf.13306",
    keywords = "medical imaging, visualization, scientific visualization, visualization, volume visualization, visualization, Medical Imaging [Visualization], Scientific Visualization [Visualization], Volume Visualization [Visualization], Multimodal Medical Data"
    }
    [Bibtex]
    @INPROCEEDINGS {vad_viktor-2017-WVE,
    author = "Viktor Vad and Jan Byska and Adam Jurcik and Ivan Viola and Meister Eduard Gr{\"o}ller and Helwig Hauser and Sergio M. Margues and Jiri Damborsky and Barbora Kozlikova",
    title = "Watergate: Visual Exploration of Water Trajectories in Protein Dynamics",
    booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine 2017",
    year = "2017",
    pages = "33--42",
    abstract = "The function of proteins is tightly related to their interactions with other molecules. The study of such interactions often requires to track the molecules that enter or exit specific regions of the proteins. This is investigated with molecular dynamics simulations, producing the trajectories of thousands of water molecules during hundreds of thousands of time steps. To ease the exploration of such rich spatio-temporal data, we propose a novel workflow for the analysis and visualization of large sets of water-molecule trajectories. Our solution consists of a set of visualization techniques, which help biochemists to classify, cluster, and filter the trajectories and to explore the properties and behavior of selected subsets in detail. Initially, we use an interactive histogram and a time-line visualization to give an overview of all water trajectories and select the interesting ones for further investigation. Further, we depict clusters of trajectories in a novel 2D representation illustrating the flows of water molecules. These views are interactively linked with a 3D representation where we show individual paths, including their simplification, as well as extracted statistical information displayed by isosurfaces. The proposed solution has been designed in tight collaboration with experts to support specific tasks in their scientific workflows. They also conducted several case studies to evaluate the usability and effectiveness of our new solution with respect to their research scenarios. These confirmed that our proposed solution helps in analyzing water trajectories and in extracting the essential information out of the large amount of input data.",
    images = "images/Watergate.png",
    thumbnails = "images/Watergate.png",
    proceedings = "In Proceedings of Eurographics Workshop on Visual Computing for Biology and Medicine",
    location = "September, 2017 Bremen, Germany",
    url = "https://www.cg.tuwien.ac.at/research/publications/2017/vad_viktor-2017-WVE/"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {vmv.20171262,
    author = "Fan, Chaoran and Hauser, Helwig",
    title = "{User-study Based Optimization of Fast and Accurate Mahalanobis Brushing in Scatterplots}",
    booktitle = "Vision, Modeling & Visualization",
    year = "2017",
    editor = "Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao",
    publisher = "The Eurographics Association",
    abstract = "Brushing is at the heart of most modern visual analytics solutions with coordinated, multiple views and effective brushing is crucial for swift and efficient processes in data exploration and analysis. Given a certain data subset that the user wishes to brush in a data visualization, traditional brushes are usually either accurate (like the lasso) or fast (e.g., a simple geometry like a rectangle or circle). In this paper, we now present a new, fast and accurate brushing technique for scatterplots, based on the Mahalanobis brush, which we have extended and then optimized using data from a user study. We explain the principal, sketchbased model of our new brushing technique (based on a simple click-and-drag interaction), the details of the user study and the related parameter optimization, as well as a quantitative evaluation, considering efficiency, accuracy, and also a comparison with the original Mahalanobis brush.",
    pdf = "pdfs/User-study based optimization of fast and accurate Mahalanobis brushing in scatterplots.pdf",
    images = "images/Mahalanobis.png",
    thumbnails = "images/Mahalanobis.png",
    isbn = "978-3-03868-049-9",
    doi = "10.2312/vmv.20171262"
    }
    [PDF] [Bibtex]
    @ARTICLE {Furmanova2017Ligand,
    author = "Furmanov{\'a}, Katar{\'\i}na and Jare{\v{s}}ov{\'a}, Miroslava and By{\v{s}}ka, Jan and Jur{\v{c}}{\'i}k, Adam and Parulek, J{\'u}lius and Hauser, Helwig and Kozl{\'i}kov{\'a}, Barbora",
    title = "Interactive exploration of ligand transportation through protein tunnels",
    journal = "BMC Bioinformatics",
    year = "2017",
    volume = "18(Suppl 2)",
    number = "22",
    month = "feb",
    abstract = "Background: Protein structures and their interaction with ligands have been in the focus of biochemistry andstructural biology research for decades. The transportation of ligand into the protein active site is often complexprocess, driven by geometric and physico-chemical properties, which renders the ligand path full of jitter andimpasses. This prevents understanding of the ligand transportation and reasoning behind its behavior along the path.Results: To address the needs of the domain experts we design an explorative visualization solution based on amulti-scale simplification model. It helps to navigate the user to the most interesting parts of the ligand trajectory byexploring different attributes of the ligand and its movement, such as its distance to the active site, changes of aminoacids lining the ligand, or ligand “stuckness�. The process is supported by three linked views – 3D representation of thesimplified trajectory, scatterplot matrix, and bar charts with line representation of ligand-lining amino acids.Conclusions: The usage of our tool is demonstrated on molecular dynamics simulations provided by the domainexperts. The tool was tested by the domain experts from protein engineering and the results confirm that it helps tonavigate the user to the most interesting parts of the ligand trajectory and to understand the ligand behavior",
    pdf = "pdfs/Furmanova2017.pdf",
    images = "images/Furmanova2016Interactive.png",
    thumbnails = "images/Furmanova2016Interactive.png",
    note = "https://doi.org/10.1186/s12859-016-1448-0"
    }
    [PDF] [Bibtex]
    @ARTICLE {Kocincova2017SS,
    author = "Kocincov{\'a}, Lucia and Jare{\v{s}}ov{\'a}, Miroslava and By{\v{s}}ka, Jan and Parulek, J{\'u}lius and Hauser, Helwig and Kozl{\'i}kov{\'a}, Barbora",
    title = "Comparative visualization of protein secondary structures",
    journal = "BMC Bioinformatics",
    year = "2017",
    volume = "18(Suppl 2)",
    number = "23",
    month = "feb",
    abstract = "Background: Protein function is determined by many factors, namely by its constitution, spatial arrangement, anddynamic behavior. Studying these factors helps the biochemists and biologists to better understand the proteinbehavior and to design proteins with modified properties. One of the most common approaches to these studies is tocompare the protein structure with other molecules and to reveal similarities and differences in their polypeptidechains.Results: We support the comparison process by proposing a new visualization technique that bridges the gapbetween traditionally used 1D and 3D representations. By introducing the information about mutual positions ofprotein chains into the 1D sequential representation the users are able to observe the spatial differences between theproteins without any occlusion commonly present in 3D view. Our representation is designed to serve namely forcomparison of multiple proteins or a set of time steps of molecular dynamics simulation.Conclusions: The novel representation is demonstrated on two usage scenarios. The first scenario aims to compare aset of proteins from the family of cytochromes P450 where the position of the secondary structures has a significantimpact on the substrate channeling. The second scenario focuses on the protein flexibility when by comparing a setof time steps our representation helps to reveal the most dynamically changing parts of the protein chain.",
    pdf = "pdfs/Kocincova2017.pdf",
    images = "images/Lucia2016Comparative.png",
    thumbnails = "images/Lucia2016Comparative.png",
    note = "https://doi.org/10.1186/s12859-016-1449-z"
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Diehl-2017-AVA,
    author = {Alexandra Diehl and Leandro Pelorosso and Kresimir Matkovic and Juan Ruiz and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Albero: A Visual Analytics Approach for Probabilistic Weather Forecasting},
    journal = {Computer Graphics Forum},
    year = {2017},
    volume = {36},
    number = {7},
    pages = {135--144},
    month = oct,
    abstract = {Probabilistic weather forecasts are amongst the most popular
    ways to quantify numerical forecast uncertainties. The analog
    regression method can quantify uncertainties and express them as
    probabilities. The method comprises the analysis of errors
    from a large database of past forecasts generated with a specific
    numerical model and observational data. Current visualization
    tools based on this method are essentially automated and provide limited
    analysis capabilities. In this paper, we propose a novel
    approach that breaks down the automatic process using the experience and
    knowledge of the users and creates a new interactive
    visual workflow. Our approach allows forecasters to study probabilistic
    forecasts, their inner analogs and observations, their
    associated spatial errors, and additional statistical information by
    means of coordinated and linked views. We designed the
    presented solution following a participatory methodology together with
    domain experts. Several meteorologists with different
    backgrounds validated the approach. Two case studies illustrate the
    capabilities of our solution. It successfully facilitates the
    analysis of uncertainty and systematic model biases for improved
    decision-making and process-quality measurements.},
    doi = {10.1111/cgf.13279},
    images = {images/Diehl-2017-AVA.jpg},
    keywords = {visual analytics, weather forecasting, uncertainty},
    pdf = {pdfs/Diehl-2017-AVA.pdf},
    thumbnails = {images/Diehl-2017-AVA.png},
    youtube = {https://www.youtube.com/watch?v=-yqoeEgkz28},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Mindek-2017-DVN,
    author = {Peter Mindek, Gabriel Mistelbauer, Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Data-Sensitive Visual Navigation},
    journal = {Computers \& Graphics},
    year = {2017},
    volume = {67},
    pages = {77--85},
    month = oct,
    note = {SCCG 2017 Best Paper Award},
    abstract = {In visualization systems it is often the case that the
    changes of the input parameters are not proportional to the visual
    change of the generated output. In this paper, we propose a model for
    enabling data-sensitive navigation for user-interface elements. This
    model is applied to normalize the user input according to the visual
    change, and also to visually communicate this normalization. In this
    way, the exploration of heterogeneous data using common interaction
    elements can be performed in an efficient way. We apply our model to the
    field of medical visualization and present guided navigation tools for
    traversing vascular structures and for camera rotation around 3D
    volumes. The presented examples demonstrate that the model scales to
    user-interface elements where multiple parameters are set
    simultaneously.},
    doi = {10.1016/j.cag.2017.05.012},
    event = {SCCG 2017},
    images = {images/Mindek-2017-DVN.jpg},
    keywords = {navigation, exploration, medical visualization},
    location = {Mikulov, Czech Republic},
    pdf = {pdfs/Mindek-2017-DVN.pdf},
    thumbnails = {images/Mindek-2017-DVN.png},
    youtube = {https://www.youtube.com/watch?v=FnhbjX7BRXI},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Swoboda-2017-VQI,
    author = {Nicolas Swoboda and Judith Moosburner and Stefan Bruckner and Jai Y. Yu and Barry J. Dickson and Katja B{\"u}hler},
    title = {Visualization and Quantification for Interactive Analysis of Neural Connectivity in Drosophila},
    journal = {Computer Graphics Forum},
    year = {2017},
    volume = {36},
    number = {1},
    pages = {160--171},
    month = jan,
    abstract = {Neurobiologists investigate the brain of the common fruit fly Drosophila
    melanogaster to discover neural circuits and link them to complex
    behavior. Formulating new hypotheses about connectivity requires
    potential connectivity information between individual neurons, indicated
    by overlaps of arborizations of two or more neurons. As the number
    of higher order overlaps (i.e., overlaps of three or more arborizations)
    increases exponentially with the number of neurons under investigation,
    visualization is impeded by clutter and quantification becomes a
    burden. Existing solutions are restricted to visual or quantitative
    analysis of pairwise overlaps, as they rely on precomputed overlap
    data. We present a novel tool that complements existing methods for
    potential connectivity exploration by providing for the first time
    the possibility to compute and visualize higher order arborization
    overlaps on the fly and to interactively explore this information
    in both its spatial anatomical context and on a quantitative level.
    Qualitative evaluation by neuroscientists and non-experts demonstrated
    the utility and usability of the tool},
    doi = {10.1111/cgf.12792},
    images = {images/Swoboda-2017-VQI.jpg},
    keywords = {visual analysis, neurobiology},
    pdf = {pdfs/Swoboda-2017-VQI.pdf},
    thumbnails = {images/Swoboda-2017-VQI.png},
    youtube = {https://www.youtube.com/watch?v=bycWGQQpqks},
    }
    [PDF] [DOI] [Bibtex]
    @Article{Lind-2017-CCR,
    author = {Andreas Johnsen Lind and Stefan Bruckner},
    title = {Comparing Cross-Sections and 3D Renderings for Surface Matching Tasks using Physical Ground Truths},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2017},
    volume = {23},
    number = {1},
    pages = {781--790},
    month = jan,
    abstract = {Within the visualization community there are some well-known techniques
    for visualizing 3D spatial data and some general assumptions about
    how perception affects the performance of these techniques in practice.
    However, there is a lack of empirical research backing up the possible
    performance differences among the basic techniques for general tasks.
    One such assumption is that 3D renderings are better for obtaining
    an overview, whereas cross sectional visualizations such as the commonly
    used Multi- Planar Reformation (MPR) are better for supporting detailed
    analysis tasks. In the present study we investigated this common
    assumption by examining the difference in performance between MPR
    and 3D rendering for correctly identifying a known surface. We also
    examined whether prior experience working with image data affects
    the participant’s performance, and whether there was any difference
    between interactive or static versions of the visualizations. Answering
    this question is important because it can be used as part of a scientific
    and empirical basis for determining when to use which of the two
    techniques. An advantage of the present study compared to other studies
    is that several factors were taken into account to compare the two
    techniques. The problem was examined through an experiment with 45
    participants, where physical objects were used as the known surface
    (ground truth). Our findings showed that: 1. The 3D renderings largely
    outperformed the cross sections; 2. Interactive visualizations were
    partially more effective than static visualizations; and 3. The high
    experience group did not generally outperform the low experience
    group.},
    doi = {10.1109/TVCG.2016.2598602},
    event = {IEEE SciVis 2016},
    images = {images/Lind-2017-CCR.jpg},
    keywords = {human-computer interaction, quantitative evaluation, volume visualization},
    location = {Baltimore, USA},
    pdf = {pdfs/Lind-2017-CCR.pdf},
    thumbnails = {images/Lind-2017-CCR.png},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Smit-2017-PAS,
    author = {Noeska Smit and Kai Lawonn and Annelot Kraima and Marco DeRuiter and Hessam Sokooti and Stefan Bruckner and Elmar Eisemann and Anna Vilanova},
    title = {PelVis: Atlas-based Surgical Planning for Oncological Pelvic Surgery},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2017},
    volume = {23},
    number = {1},
    pages = {741--750},
    month = jan,
    abstract = {Due to the intricate relationship between the pelvic organs and vital
    structures, such as vessels and nerves, pelvic anatomy is often considered
    to be complex to comprehend. In oncological pelvic surgery, a trade-off
    has to be made between complete tumor resection and preserving function
    by preventing damage to the nerves. Damage to the autonomic nerves
    causes undesirable post-operative side-effects such as fecal and
    urinal incontinence, as well as sexual dysfunction in up to 80 percent
    of the cases. Since these autonomic nerves are not visible in pre-operative
    MRI scans or during surgery, avoiding nerve damage during such a
    surgical procedure becomes challenging. In this work, we present
    visualization methods to represent context, target, and risk structures
    for surgical planning. We employ distance-based and occlusion management
    techniques in an atlas-based surgical planning tool for oncological
    pelvic surgery. Patient-specific pre-operative MRI scans are registered
    to an atlas model that includes nerve information. Through several
    interactive linked views, the spatial relationships and distances
    between the organs, tumor and risk zones are visualized to improve
    understanding, while avoiding occlusion. In this way, the surgeon
    can examine surgically relevant structures and plan the procedure
    before going into the operating theater, thus raising awareness of
    the autonomic nerve zone regions and potentially reducing post-operative
    complications. Furthermore, we present the results of a domain expert
    evaluation with surgical oncologists that demonstrates the advantages
    of our approach.},
    doi = {10.1109/TVCG.2016.2598826},
    event = {IEEE SciVis 2016},
    images = {images/Smit-2017-PAS.jpg},
    keywords = {atlas, surgical planning, medical visualization},
    location = {Baltimore, USA},
    pdf = {pdfs/Smit-2017-PAS.pdf},
    thumbnails = {images/Smit-2017-PAS.png},
    youtube = {https://www.youtube.com/watch?v=vHp05I5-hp8},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Solteszova-2017-OFS,
    author = {Veronika \v{S}olt{\'e}szov{\'a} and {\AA}smund Birkeland and Sergej Stoppel and Ivan Viola and Stefan Bruckner},
    title = {Output-Sensitive Filtering of Streaming Volume Data},
    journal = {Computer Graphics Forum},
    year = {2017},
    volume = {36},
    number = {1},
    pages = {249--262},
    month = jan,
    abstract = {Real-time volume data acquisition poses substantial challenges for
    the traditional visualization pipeline where data enhancement is
    typically seen as a pre-processing step. In the case of 4D ultrasound
    data, for instance, costly processing operations to reduce noise
    and to remove artifacts need to be executed for every frame. To enable
    the use of high quality filtering operations in such scenarios, we
    propose an output-sensitive approach to the visualization of streaming
    volume data. Our method evaluates the potential contribution of all
    voxels to the final image, allowing us to skip expensive processing
    operations that have little or no effect on the visualization. As
    filtering operations modify the data values which may affect the
    visibility, our main contribution is a fast scheme to predict their
    maximum effect on the final image. Our approach prioritizes filtering
    of voxels with high contribution to the final visualization based
    on a maximal permissible error per pixel. With zero permissible error,
    the optimized filtering will yield a result identical to filtering
    of the entire volume. We provide a thorough technical evaluation
    of the approach and demonstrate it on several typical scenarios that
    require on-the-fly processing.},
    doi = {10.1111/cgf.12799},
    images = {images/Solteszova-2017-OFS.jpg},
    keywords = {output-sensitive processing, volume data, filtering},
    pdf = {pdfs/Solteszova-2017-OFS.pdf},
    thumbnails = {images/Solteszova-2017-OFS.png},
    youtube = {https://www.youtube.com/watch?v=xGPs560ttp0},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Stoppel-2017-VPI,
    author = {Sergej Stoppel and Stefan Bruckner},
    title = {Vol²velle: Printable Interactive Volume Visualization},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2017},
    volume = {23},
    number = {1},
    pages = {861--870},
    month = jan,
    abstract = {Interaction is an indispensable aspect of data visualization. The
    presentation of volumetric data, in particular, often significantly
    benefits from interactive manipulation of parameters such as transfer
    functions, rendering styles, or clipping planes. However, when we
    want to create hardcopies of such visualizations, this essential
    aspect is lost. In this paper, we present a novel approach for creating
    hardcopies of volume visualizations which preserves a certain degree
    of interactivity. We present a method for automatically generating
    Volvelles, printable tangible wheel charts that can be manipulated
    to explore different parameter settings. Our interactive system allows
    the flexible mapping of arbitrary visualization parameters and supports
    advanced features such as linked views. The resulting designs can
    be easily reproduced using a standard printer and assembled within
    a few minutes.},
    doi = {10.1109/TVCG.2016.2599211},
    event = {IEEE SciVis 2016},
    images = {images/Stoppel-2017-VPI.jpg},
    keywords = {physical visualization, interaction, volume visualization, illustrative visualization},
    location = {Baltimore, USA},
    pdf = {pdfs/Stoppel-2017-VPI.pdf},
    thumbnails = {images/Stoppel-2017-VPI.png},
    youtube = {https://www.youtube.com/watch?v=Z1K8t-FCiXI},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Kolesar-2017-FCC,
    author = {Ivan Kolesar and Stefan Bruckner and Ivan Viola and Helwig Hauser},
    title = {A Fractional Cartesian Composition Model for Semi-spatial Comparative Visualization Design},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2017},
    volume = {23},
    number = {1},
    pages = {851--860},
    month = jan,
    abstract = {The study of spatial data ensembles leads to substantial visualization
    challenges in a variety of applications. In this paper, we present
    a model for comparative visualization that supports the design of
    according ensemble visualization solutions by partial automation.
    We focus on applications, where the user is interested in preserving
    selected spatial data characteristics of the data as much as possible—even
    when many ensemble members should be jointly studied using comparative
    visualization. In our model, we separate the design challenge into
    a minimal set of user-specified parameters and an optimization component
    for the automatic configuration of the remaining design variables.
    We provide an illustrated formal description of our model and exemplify
    our approach in the context of several application examples from
    different domains in order to demonstrate its generality within the
    class of comparative visualization problems for spatial data ensembles.},
    doi = {10.1109/TVCG.2016.2598870},
    event = {IEEE SciVis 2016},
    images = {images/Kolesar-2017-FCC.jpg},
    keywords = {visualization models, integrating spatial and non-spatial data visualization, design methodologies},
    location = {Baltimore, USA},
    pdf = {pdfs/Kolesar-2017-FCC.pdf},
    project = {physioillustration},
    thumbnails = {images/Kolesar-2017-FCC.png},
    youtube = {https://www.youtube.com/watch?v=_zk67fmryok},
    }

2016

    [PDF] [Bibtex]
    @ARTICLE {Byska2016AnimoAminoMiner,
    author = "Jan By{\v{s}}ka and Le Muzic, Mathieu and Gr{\"o}ller, Eduard M. and Viola, Ivan and Kozl{\'i}kov{\'a}, Barbora",
    title = "AnimoAminoMiner: Exploration of Protein Tunnels and their Properties in Molecular Dynamics",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2016",
    volume = "22",
    number = "1",
    pages = "747--756",
    abstract = "In this paper we propose a novel method for the interactive exploration of protein tunnels. The basic principle of our approach is that we entirely abstract from the 3D/4D space the simulated phenomenon is embedded in. A complex 3D structure and its curvature information is represented only by a straightened tunnel centerline and its width profile. This representation focuses on a key aspect of the studied geometry and frees up graphical estate to key chemical and physical properties represented by surroundingamino acids. The method shows the detailed tunnel profile and its temporal aggregation. The profile is interactively linked with a visual overview of all amino acids which are lining the tunnel over time. In this overview, each amino acid is represented by a set of colored lines depicting the spatial and temporal impact of the amino acid on the corresponding tunnel. This representation clearly shows the importance of amino acids with respect to selected criteria. It helps the biochemists to select the candidate amino acids for mutation which changes the protein function in a desired way. The AnimoAminoMiner was designed in close cooperation with domain experts. Its usefulness is documented by their feedback and a case study, which are included.",
    pdf = "pdfs/2016-Byska-AnimoAminoMiner.pdf",
    images = "images/IvanViola2016.png",
    thumbnails = "images/IvanViola2016.png",
    publisher = "IEEE"
    }
    [Bibtex]
    @MISC {Stoppel2015ConfReport,
    author = "Sergej Stoppel",
    title = "Conference Report IEEE VIS 2014",
    month = "January",
    year = "2016",
    abstract = "Conference report about the IEEE VIS 2014 in Paris.",
    images = "images/Shneiderman_Gerson_Pushups.PNG",
    thumbnails = "images/Shneiderman_Gerson_Pushups.PNG",
    url = "http://www.norsigd.no/norsigd_info/nsi-1-15.pdf"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Smit2016SLINE,
    author = "Nils Lichtenberg and Noeska Smit and Christian Hansen and Kai Lawonn",
    title = "Sline: Seamless Line Illustration for Interactive Biomedical Visualization",
    booktitle = "Proceedings of VCBM 2016",
    year = "2016",
    month = "sep",
    abstract = "In medical visualization of surface information, problems often arise when visualizing several overlapping structures simultaneously. There is a trade-off between visualizing multiple structures in a detailed way and limiting visual clutter, in order to allow users to focus on the main structures. Illustrative visualization techniques can help alleviate these problems by defining a level of abstraction per structure. However, clinical uptake of these advanced visualization techniques so far has been limited due to the complex parameter settings required. To bring advanced medical visualization closer to clinical application, we propose a novel illustrative technique that offers a seamless transition between various levels of abstraction and detail. Using a single comprehensive parameter, users are able to quickly define a visual representation per structure that fits the visualization requirements for focus and context structures. This technique can be applied to any biomedical context in which multiple surfaces are routinely visualized, such as neurosurgery, radiotherapy planning or drug design. Additionally, we introduce a novel hatching technique, that runs in real-time and does not require texture coordinates. An informal evaluation with experts from different biomedical domains reveals that our technique allows users to design focus-and-context visualizations in a fast and intuitive manner.",
    pdf = "pdfs/Lichtenberg-2016-SLINE.pdf",
    images = "images/Smit-2016-SLINE.PNG",
    thumbnails = "images/Smit-2016-SLINE.jpg",
    proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
    event = "VCBM 2016",
    keywords = "surface rendering, medical visualization, illustrative rendering",
    location = "Bergen, Norway"
    }
    [DOI] [Bibtex]
    @ARTICLE {Michael2016Visual,
    author = "Michael Krone and Barbora Kozlikova and Norbert Lindow and Marc Baaden and Daniel Baum, and Julius Parulek and Hans-Christian Hege and Ivan Viola",
    title = "Visual Analysis of Biomolecular Cavities: State of the Art",
    journal = "Computer Graphics Forum",
    year = "2016",
    abstract = "In this report we review and structure the branch of molecular visualization that is concerned with the visual analysis of cavities in macromolecular protein structures. First the necessary background, the domain terminology, and the goals of analytical reasoning are introduced. Based on a comprehensive collection of relevant research works, we present a novel classification for cavity detection approaches and structure them into four distinct classes: grid-based, Voronoi-based, surface-based, and probe-based methods. The subclasses are then formed by their combinations. We match these approaches with corresponding visualization technologies starting with direct 3D visualization, followed with non-spatial visualization techniques that for example abstract the interactions between structures into a relational graph, straighten the cavity of interest to see its profile in one view, or aggregate the time sequence into a single contour plot. We also discuss the current state of methods for the visual analysis of cavities in dynamic data such as molecular dynamics simulations. Finally, we give an overview of the most common tools that are actively developed and used in the structural biology and biochemistry research. Our report is concluded by an outlook on future challenges in the field.",
    images = "images/STARcavities2016.png",
    thumbnails = "images/STARcavities2016.png",
    publisher = "The Eurographics Association and John Wiley \& Sons Ltd.",
    issn = "1467-8659",
    doi = "10.1111/cgf.12928",
    project = "physioillustration"
    }
    [Bibtex]
    @INPROCEEDINGS {Kolesar2016VCBM,
    author = "Ivan Kolesar and Jan Byska and Julius Parulek andHelwig Hauser and Barbora Kozlikova",
    title = "Unfolding and Interactive Exploration of Protein Tunnels andtheir Dynamics",
    booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine",
    year = "2016",
    pages = "1--10",
    month = "sep",
    abstract = "The presence of tunnels in protein structures substantially influences their reactivity with other molecules. Therefore, studying their properties and changes over time has been in the scope of biochemists for decades. In this paper we introduce a novel approach for comparative visualization and exploration of ensembles of tunnels. Our goal is to overcome occlusion problems present in traditional tunnel representations while providing users a quick way to navigate through the input dataset to identify potentially interesting tunnels. First, we unfold the input tunnels to a 2D representation enabling to observe the mutual position of amino acids forming the tunnel surface and the amount of surface they influence. These 2D images are subsequently described by image moments commonly used in image processing. This way we are able to detect similarities and outliers in the dataset, which are visualized as clusters in a scatterplot graph. The same coloring scheme is used in the linked bar chart enabling to detect the position of the cluster members over time. These views provide a way to select a subset of potentially interesting tunnels that can be further explored in detail using the 2D unfolded view and also traditional 3D representation. The usability of our approach is demonstrated on case studies conducted by the domain experts.",
    images = "images/Kolesar-2016-VCBM.png",
    thumbnails = "images/Kolesar-2016-VCBM-thumbnail.jpg",
    proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
    keywords = "unfolding, storytelling, game visualization",
    location = "Bergen, Norway",
    project = "physioillustration"
    }
    [PDF] [DOI] [Bibtex]
    @InProceedings{Klein-2016-TIV,
    author = {Tobias Klein and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger and Peter Rautek},
    title = {Towards Interactive Visual Exploration of Parallel Programs using a Domain-Specific Language},
    booktitle = {Proceedings of the International Workshop on OpenCL 2016},
    year = {2016},
    month = apr,
    abstract = {The use of GPUs and the massively parallel computing paradigm have
    become wide-spread. We describe a framework for the interactive visualization
    and visual analysis of the run-time behavior of massively parallel
    programs, especially OpenCL kernels. This facilitates understanding
    a program's function and structure, finding the causes of possible
    slowdowns, locating program bugs, and interactively exploring and
    visually comparing different code variants in order to improve performance
    and correctness. Our approach enables very specific, user-centered
    analysis, both in terms of the recording of the run-time behavior
    and the visualization itself. Instead of having to manually write
    instrumented code to record data, simple code annotations tell the
    source-to-source compiler which code instrumentation to generate
    automatically. The visualization part of our framework then enables
    the interactive analysis of kernel run-time behavior in a way that
    can be very specific to a particular problem or optimization goal,
    such as analyzing the causes of memory bank conflicts or understanding
    an entire parallel algorithm.},
    doi = {10.1145/2909437.2909459},
    event = {IWOCL 2016},
    extra = {pdfs/Klein-2016-TIV-Poster.pdf},
    images = {images/Klein-2016-TIV.jpg},
    keywords = {domain specific languages, GPU programming, visual exploration},
    location = {Vienna, Austria},
    owner = {bruckner},
    pdf = {pdfs/Klein-2016-TIV.pdf},
    thumbnails = {images/Klein-2016-TIV.png},
    }
    [PDF] [DOI] [Bibtex]
    @Article{Labschuetz-2016-JJC,
    author = {Matthias Labsch{\"u}tz and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger and Peter Rautek},
    title = {JiTTree: A Just-in-Time Compiled Sparse GPU Volume Data Structure},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2016},
    volume = {22},
    number = {1},
    pages = {1025--1034},
    month = jan,
    abstract = {Abstract—Sparse volume data structures enable the efficient representation
    of large but sparse volumes in GPU memory for com putation and visualization.
    However, the choice of a specific data structure for a given data
    set depends on several factors, such as the memory budget, the sparsity
    of the data, and data access patterns. In general, there is no single
    optimal sparse data structure, but a set of several candidates with
    individual strengths and drawbacks. One solution to this problem
    are hybrid data structures which locally adapt themselves to the
    sparsity. However, they typically suffer from increased traversal
    overhead which limits their utility in many applications. This paper
    presents JiTTree, a novel sparse hybrid volume data structure that
    uses just-in-time compilation to overcome these problems. By combining
    multiple sparse data structures and reducing traversal overhead we
    leverage their individual advantages. We demonstrate that hybrid
    data structures adapt well to a large range of data sets. They are
    especially superior to other sparse data structures for data sets
    that locally vary in sparsity. Possible optimization criteria are
    memory, performance and a combination thereof. Through just-in-time
    (JIT) compilation, JiTTree reduces the traversal overhead of the
    resulting optimal data structure. As a result, our hybrid volume
    data structure enables efficient computations on the GPU, while being
    superior in terms of memory usage when compared to non-hybrid data
    structures.},
    doi = {10.1109/TVCG.2015.2467331},
    event = {IEEE SciVis 2015},
    images = {images/Labschuetz-2016-JJC.jpg},
    keywords = {data transformation and representation, GPUs and multi-core architectures, volume rendering},
    location = {Chicago, USA},
    pdf = {pdfs/Labschuetz-2016-JJC.pdf},
    thumbnails = {images/Labschuetz-2016-JJC.png},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @InProceedings{Stoppel-2016-GIR,
    author = {Sergej Stoppel and Erlend Hodneland and Helwig Hauser and Stefan Bruckner},
    title = {Graxels: Information Rich Primitives for the Visualization of Time-Dependent Spatial Data},
    booktitle = {Proceedings of VCBM 2016},
    year = {2016},
    pages = {183--192},
    month = sep,
    abstract = {Time-dependent volumetric data has important applications in areas
    as diverse as medicine, climatology, and engineering. However, the
    simultaneous quantitative assessment of spatial and temporal features
    is very challenging. Common visualization techniques show either
    the whole volume in one time step (for example using direct volume
    rendering) or let the user select a region of interest (ROI) for
    which a collection of time-intensity curves is shown. In this paper,
    we propose a novel approach that dynamically embeds quantitative
    detail views in a spatial layout. Inspired by the concept of small
    multiples, we introduce a new primitive graxel (graph pixel). Graxels
    are view dependent primitives of time-intensity graphs, generated
    on-the-fly by aggregating per-ray information over time and image
    regions. Our method enables the detailed feature-aligned visual analysis
    of time-dependent volume data and allows interactive refinement and
    filtering. Temporal behaviors like frequency relations, aperiodic
    or periodic oscillations and their spatial context are easily perceived
    with our method. We demonstrate the power of our approach using examples
    from medicine and the natural sciences.},
    doi = {10.2312/vcbm.20161286},
    event = {VCBM 2016},
    images = {images/Stoppel-2016-GIR.jpg},
    keywords = {time-dependent data, volume data, small multiples},
    location = {Bergen, Norway},
    pdf = {pdfs/Stoppel-2016-GIR.pdf},
    thumbnails = {images/Stoppel-2016-GIR.png},
    youtube = {https://www.youtube.com/watch?v=UsClj3ytd0Y},
    }

2015

    [PDF] [Bibtex]
    @MISC {Hauser2015Austria,
    author = "Helwig Hauser",
    title = "Integrating Spatial \& Non-spatial Data in Visualization",
    howpublished = "Invited talk",
    month = "October",
    year = "2015",
    abstract = "New opportunities in data science, such as the consideration of cohort study data, require new approaches to the appropriate design of an effective visualization. We need to capitalize on successful solutions from previous research, of course, but we should also explore new strategies that challenge our already established mindset in visualization. In this talk, I address the specific challenge of integrating spatial and non-spatial data in visualization, in particular, when the spatial aspect of the data is of great importance to the user---this could relate to the morphological information in a 3D medical scan or the geometrical aspects of flow features in a CFD simulation. In data visualizaiton, the actual mapping step---from data to a visual form---is certainly crucial and we should strive to optimally exploit the great opportunities that we have in designing this step. In data-intensive sciences, the study objects of interest are increasingly often represented by extensive and rich datasets (aka. big data)---while traditionally the focus of visualization was on individual, static datasets, we now face dynamic data, representing entire ensembles of study entities, etc. Visualization gets a lot harder, when facing such new 'big data' challenges---both on the designer sider as well as also on the user side. At the same time, however, also the potential for impact is increasing, which amounts to a fantastic motivation for new basic research in visualization.",
    pdf = "pdfs/2015-10-14--HHauser--InvTalk--print--2up.pdf",
    images = "images/ThumbPicHHAustria2015.png",
    thumbnails = "images/ThumbPicHHAustria2015.png",
    location = "Vienna, Austria"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2015SUBSEA,
    author = "Helwig Hauser",
    title = "Big Data - visualization and visual analytics",
    howpublished = "Invited talk at the NCE Subsea Forum",
    month = "March",
    year = "2015",
    pdf = "pdfs/2015-03-19--NCE--BigDataVA--print2up.pdf",
    images = "images/ThumbnailBigData.jpg",
    thumbnails = "images/ThumbnailBigData.jpg",
    day = "19",
    location = "Bergen, Norway"
    }
    [DOI] [Bibtex]
    @ARTICLE {alsallakh2015state,
    author = "Alsallakh, Bilal and Micallef, Luana and Aigner, Wolfgang and Hauser, Helwig and Miksch, Silvia and Rodgers, Peter",
    title = "The State-of-the-Art of Set Visualization",
    journal = "Computer Graphics Forum",
    year = "2015",
    abstract = "Sets comprise a generic data model that has been used in a variety of data analysis problems. Such problems involve analysing and visualizing set relations between multiple sets defined over the same collection of elements. However, visualizing sets is a non-trivial problem due to the large number of possible relations between them. We provide a systematic overview of state-of-the-art techniques for visualizing different kinds of set relations. We classify these techniques into six main categories according to the visual representations they use and the tasks they support. We compare the categories to provide guidance for choosing an appropriate technique for a given problem. Finally, we identify challenges in this area that need further research and propose possible directions to address these challenges. Further resources on set visualization are available at http://www.setviz.net.",
    images = "images/ThumbNailIMG--SetVisSTAR.png",
    thumbnails = "images/ThumbNailIMG--SetVisSTAR.png",
    organization = "Wiley Online Library",
    booktitle = "Computer Graphics Forum",
    doi = "10.1111/cgf.12722"
    }
    [Bibtex]
    @INPROCEEDINGS {cellVIEW_2015,
    author = "Mathieu Le Muzic and Ludovic Autin and Julius Parulek and Ivan Viola",
    title = "cellVIEW: a Tool for Illustrative and Multi-Scale Rendering of Large Biomolecular Datasets",
    booktitle = "EG Workshop on Visual Computing for Biology and Medicine",
    year = "2015",
    month = "sep",
    abstract = "In this article we introduce cellVIEW, a new system to interactively visualize large biomolecular datasets on the atomic level. Our tool is unique and has been specifically designed to match the ambitions of our domain experts to model and interactively visualize structures comprised of several billions atom. The cellVIEW system integrates acceleration techniques to allow for real-time graphics performance of 60 Hz display rate on datasets representing large viruses and bacterial organisms. Inspired by the work of scientific illustrators, we propose a level-of-detail scheme which purpose is two-fold: accelerating the rendering and reducing visual clutter. The main part of our datasets is made out of macromolecules, but it also comprises nucleic acids strands which are stored as sets of control points. For that specific case, we extend our rendering method to support the dynamic generation of DNA strands directly on the GPU. It is noteworthy that our tool has been directly implemented inside a game engine. We chose to rely on a third party engine to reduce software development work-load and to make bleeding-edge graphics techniques more accessible to the end-users. To our knowledge cellVIEW is the only suitable solution for interactive visualization of large bimolecular landscapes on the atomic level and is freely available to use and extend.",
    images = "images/cellview2015.png",
    thumbnails = "images/cellview2015.png",
    proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {splechtna2015interactive,
    author = "Splechtna, Rainer and Matkovic, Kresimir and Gracanin, Denis and Jelovic, Mario and Hauser, Helwig",
    title = "Interactive visual steering of hierarchical simulation ensembles",
    booktitle = "Visual Analytics Science and Technology (VAST), 2015 IEEE Conference on",
    year = "2015",
    pages = "89--96",
    organization = "IEEE",
    abstract = "Multi-level simulation models, i.e., models where different components are simulated using sub-models of varying levels of complexity, belong to the current state-of-the-art in simulation. The existing analysis practice for multi-level simulation results is to manually compare results from different levels of complexity, amounting to a very tedious and error-prone, trial-and-error exploration process. In this paper, we introduce hierarchical visual steering, a new approach to the exploration and design of complex systems. Hierarchical visual steering makes it possible to explore and analyze hierarchical simulation ensembles at different levels of complexity. At each level, we deal with a dynamic simulation ensemble - the ensemble grows during the exploration process. There is at least one such ensemble per simulation level, resulting in a collection of dynamic ensembles, analyzed simultaneously. The key challenge is to map the multi-dimensional parameter space of one ensemble to the multi-dimensional parameter space of another ensemble (from another level). In order to support the interactive visual analysis of such complex data we propose a novel approach to interactive and semi-automatic parameter space segmentation and comparison. The approach combines a novel interaction technique and automatic, computational methods - clustering, concave hull computation, and concave polygon overlapping - to support the analysts in the cross-ensemble parameter space mapping. In addition to the novel parameter space segmentation we also deploy coordinated multiple views with standard plots. We describe the abstract analysis tasks, identified during a case study, i.e., the design of a variable valve actuation system of a car engine. The study is conducted in cooperation with experts from the automotive industry. Very positive feedback indicates the usefulness and efficiency of the newly proposed approach.",
    images = "images/ThumbNailIMG--HierSteering.png",
    thumbnails = "images/ThumbNailIMG--HierSteering.png",
    doi = "10.1109/VAST.2015.7347635"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2015IRIS,
    author = "Helwig Hauser",
    title = "Medical Visualization Research at the VisGroup @ UiB.no/ii",
    howpublished = "Invited talk at IRIS",
    month = "November",
    year = "2015",
    abstract = "Established about eight years ago, the Visualization Research Group is the youngest of six research groups at the Department of Informatics, UiB, focusing on application-oriented basic research in visualization. Medicine and related disciplines (such as biomedicine, biology, etc.) stand for a growing number of grand visualization challenges and the vivid interdisciplinary MedViz network in Bergen gives ample opportunities for internationally recognized visualization research. In this talk, an overview of the visualization research group [1] is given, together with a short review of selected research projects in medical visualization.",
    pdf = "pdfs/2015-11-25--PresAtIRIS--print2up.pdf",
    images = "images/ThumbNailIRIS.jpg",
    thumbnails = "images/ThumbNailIRIS.jpg",
    day = "25",
    location = "Bergen, Norway"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2015VIS,
    author = "Helwig Hauser",
    title = "From Anatomy to Physiology in Medical Visualization",
    howpublished = "Tutorial talk at IEEE VIS 2015",
    month = "October",
    year = "2015",
    abstract = "Generally, medical visualization assists the diagnosis of diseases as well as the treatment of patients. Capturing the patients anatomy, which to a large degree is in the focus of traditional MedViz, certainly is one important key to the success of medical visualization. At least equally important, if not even more, is the consideration of physiology, entailing the complex of function (or malfunction) of the patient. Modern imaging modalities extend beyond the simple depiction of static anatomical snapshots to capturing temporal processes as well as to covering multiple scales of physiology eventually linking molecular biology to medicine. The visualization of human physiology complements other techniques, for example lab tests for quantifying certain physiological functions. We deem ourselves at the beginning of an interesting extension of MedViz research to increasingly capture physiology in addition to anatomy.",
    pdf = "pdfs/2015-10-25--VIS2015--TutTalkHH--print2up.pdf",
    images = "images/ThumbnailVisTut.png",
    thumbnails = "images/ThumbnailVisTut.png",
    day = "25",
    location = "Chicago, Illinois, USA"
    }
    [Bibtex]
    @INPROCEEDINGS {PBVRVis2015026,
    author = "Matkovic, K and Gracanin, D and Jelovi{\'{c}}, M and Hauser, H",
    title = "Interactive Visual Analysis of Large Simulation Ensembles",
    booktitle = "Proceedings of Winter Simulation Conference (WSC 2015, to appear)",
    year = "2015",
    abstract = "Recent advancements in simulation and computing make it possible to compute large simulation ensembles. A simulation ensemble consists of multiple simulation runs of the same model with different values of control parameters. In order to cope with ensemble data, a modern analysis methodology is necessary. In this paper, we present our experience with simulation ensemble exploration and steering by means of interactive visual analysis. We describe our long-term collaboration with fuel injection experts from the automotive industry. We present how interactive visual analysis can be used to gain a deep understanding in the ensemble data, and how it can be used, in a combination with automatic methods, to steer the ensemble creation, even for very complex systems. Very positive feedback from domain experts motivated us, a team of visualization and simulation experts, to present this research to the simulation community.",
    images = "images/ThumbNailIMG--EnsembleIVA.png",
    thumbnails = "images/ThumbNailIMG--EnsembleIVA.png"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {7156384,
    author = "Le Muzic, Mathieu and Waldner, Manuela and Parulek, Julius and Viola, Ivan",
    title = "Illustrative Timelapse: A technique for illustrative visualization of particle-based simulations",
    booktitle = "Visualization Symposium (PacificVis), 2015 IEEE Pacific",
    year = "2015",
    pages = "247-254",
    month = "April",
    abstract = "Animated movies are a popular way to communicate complex phenomena in cell biology to the broadaudience. Animation artists apply sophisticated illustration techniques to communicate a story, while trying to maintain a realistic representation of a complex dynamic environment. Since suchhand-crafted animations are time-consuming and cost-intensive to create, our goal is to formalizeillustration techniques used by artists to facilitate the automatic creation of visualizations generated from mesoscale particle-based molecular simulations. Our technique Illustrative Timelapse supports visual exploration of complex biochemical processes in dynamic environments by(1) seamless temporal zooming to observe phenomena in different temporal resolutions, (2) visualabstraction of molecular trajectories to ensure that observers are able to visually follow themain actors, (3) increased visual focus on events of interest, and (4) lens effects to preserve arealistic representation of the environment in the context. Results from a first user studyindicate that visual abstraction of trajectories improves the ability to follow a story and isalso appreciated by users. Lens effects increased the perceived amount of molecular motion in theenvironment while trading off traceability of individual molecules.",
    images = "images/illustrative_timelapse.png",
    thumbnails = "images/illustrative_timelapse.png",
    proceedings = "Proceedings of IEEE Pacific Visualization",
    keywords = "Biological system modeling;Data models;Data visualization;Lenses;Trajectory;Videos;Visualization;I.3.7[COMPUTER GRAPHICS]: Three-Dimensional Graphics and Realism—Animation;I.6.3 [SIMULATION AND MODELING]: Applications—",
    doi = "10.1109/PACIFICVIS.2015.7156384",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @ARTICLE {Byska2015MC,
    author = "ByÅ¡ka, J. and JurÄ?ík, A. and Gröller, M. E. and Viola, I. and Kozlíková, B.",
    title = "MoleCollar and Tunnel Heat Map Visualizations for Conveying Spatio-Temporo-Chemical Properties Across and Along Protein Voids",
    journal = "Computer Graphics Forum",
    year = "2015",
    volume = "34",
    number = "3",
    pages = "1--10",
    abstract = "Studying the characteristics of proteins and their inner void space, including their geometry,physico-chemical properties and dynamics are instrumental for evaluating the reactivity of theprotein with other small molecules. The analysis of long simulations of molecular dynamics produces a large number of voids which have to be further explored and evaluated. In this paper we propose three new methods: two of them convey important properties along the long axis of a selected void during molecular dynamics and one provides a comprehensive picture across the void. The first two proposed methods use a specific heat map to present two types of information: an overview of all detected tunnels in the dynamics and their bottleneck width andstability over time, and an overview of a specific tunnel in the dynamics showing the bottleneck position and changes of the tunnel length over time. These methods help to select asmall subset of tunnels, which are explored individually and in detail. For this stage we propose the third method, which shows in one static image the temporal evolvement of the shapeof the most critical tunnel part, i.e., its bottleneck. This view is enriched with abstractdepictions of different physicochemical properties of the amino acids surrounding the bottleneck. The usefulness of our newly proposed methods is demonstrated on a case study andthe feedback from the domain experts is included. The biochemists confirmed that our novel methods help to convey the information about the appearance and properties of tunnels in a very intuitive and comprehensible manner.",
    images = "images/cgf12612-fig-0001.png",
    thumbnails = "images/cgf12612-fig-0001.png",
    issn = "1467-8659",
    url = "http://dx.doi.org/10.1111/cgf.12612",
    doi = "10.1111/cgf.12612",
    keywords = "Categories and Subject Descriptors (according to ACM CCS), I.3.6 [Computer Graphics]: Picture/Image Generation—Line and curve generation"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {eurovisstar20151112,
    author = "Kozlikova, Barbora and Krone, Michael and Lindow, Norbert and Falk, Martin and Baaden, Marc and Baum, Daniel and Viola, Ivan and Parulek, Julius and Hege, Hans-Christian",
    title = "Visualization of Biomolecular Structures: State of the Art",
    booktitle = "Eurographics Conference on Visualization (EuroVis) - STARs",
    year = "2015",
    editor = "R. Borgo and F. Ganovelli and I. Viola",
    volume = "-",
    publisher = "The Eurographics Association",
    abstract = "Structural properties of molecules are of primary concern in many fields. This report provides a comprehensiveoverview on techniques that have been developed in the fields of molecular graphics and visualization with a focuson applications in structural biology. The field heavily relies on computerized geometric and visual representationsof three-dimensional, complex, large, and time-varying molecular structures. The report presents a taxonomy thatdemonstrates which areas of molecular visualization have already been extensively investigated and where the fieldis currently heading. It discusses visualizations for molecular structures, strategies for efficient display regardingimage quality and frame rate, covers different aspects of level of detail, and reviews visualizations illustrating thedynamic aspects of molecular simulation data. The report concludes with an outlook on promising and importantresearch topics to enable further success in advancing the knowledge about interaction of molecular structures.",
    images = "images/molvis_star.png",
    thumbnails = "images/molvis_star.png",
    proceedings = "Eurographics Conference on Visualization (EuroVis) - STARs",
    doi = "10.2312/eurovisstar.20151112",
    journal = "-",
    number = "-",
    keywords = "-",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @ARTICLE {Brambilla15Expressive,
    author = "Andrea Brambilla and Helwig Hauser",
    title = "Expressive Seeding of Multiple Stream Surfaces for Interactive Flow Exploration",
    journal = "Computers \& Graphics",
    year = "2015",
    volume = "47",
    pages = "123--134",
    abstract = "Integral surfaces, such as stream and path surfaces, are highly effective in the context of the exploration and the analysis of the long-term behavior of three-dimensional flows. However, specifying the seeding curves that lead to an expressive set of integral surfaces is a challenging and cumbersome task. In this paper, we propose an algorithm for automatically seeding multiple stream surfaces around a user-specified location of interest. The process is guided by a streamline similarity measure. Within the resulting integral surfaces, adjacent streamlines are as similar as possible to each other. In addition, we aim at conveying different aspects of the flow behavior with each surface. This is achieved by maximizing the dissimilarity between streamlines from different stream surfaces. The capabilities of our technique are demonstrated on a number of application cases. We provide a qualitative comparison with two state-of-the-art approaches. We report from our detailed exchange with a domain expert concerning the expressiveness and usefulness of our approach. A thorough analysis of the few parameters involved is provided. ",
    images = "images/Brambilla15Expressive01.png, images/Brambilla15Expressive02.png",
    thumbnails = "images/Brambilla15Expressive01_thumb.png, images/Brambilla15Expressive02_thumb.png",
    publisher = "Elsevier",
    doi = "http://dx.doi.org/10.1016/j.cag.2015.01.002",
    url = "http://www.sciencedirect.com/science/article/pii/S0097849315000035",
    keywords = "Flow visualization; Stream surface selection; Visibility management"
    }
    [PDF] [Bibtex]
    @Article{Angelelli-2015-PQA,
    author = {Paolo Angelelli and Stefan Bruckner},
    title = {Performance and Quality Analysis of Convolution-Based Volume Illumination},
    journal = {Journal of WSCG},
    year = {2015},
    volume = {23},
    number = {2},
    pages = {131--138},
    month = {jun},
    abstract = {Convolution-based techniques for volume rendering are among the fastest
    in the on-the-fly volumetric illumination category. Such methods,
    however, are still considerably slower than conventional local illumination
    techniques. In this paper we describe how to adapt two commonly used
    strategies for reducing aliasing artifacts, namely pre-integration
    and supersampling, to such techniques. These strategies can help
    reduce the sampling rate of the lighting information (thus the number
    of convolutions), bringing considerable performance benefits. We
    present a comparative analysis of their effectiveness in offering
    performance improvements. We also analyze the (negligible) differences
    they introduce when comparing their output to the reference method.
    These strategies can be highly beneficial in setups where direct
    volume rendering of continuously streaming data is desired and continuous
    recomputation of full lighting information is too expensive, or where
    memory constraints make it preferable not to keep additional precomputed
    volumetric data in memory. In such situations these strategies make
    single pass, convolution-based volumetric illumination models viable
    for a broader range of applications, and this paper provides practical
    guidelines for using and tuning such strategies to specific use cases.},
    images = {images/Angelelli-2015-PQA.jpg},
    keywords = {volume rendering, global illumination, scientific visualization, medical visualization},
    pdf = {pdfs/Angelelli-2015-PQA.pdf},
    thumbnails = {images/Angelelli-2015-PQA.png},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Diehl-2015-VAS,
    author = {Alexandra Diehl and Leandro Pelorosso and Claudio Delrieux and Celeste Saulo and Juan Ruiz and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Visual Analysis of Spatio-Temporal Data: Applications in Weather Forecasting},
    journal = {Computer Graphics Forum},
    year = {2015},
    volume = {34},
    number = {3},
    pages = {381--390},
    month = {may},
    abstract = {Weather conditions affect multiple aspects of human life such as economy,
    safety, security, and social activities. For this reason, weather
    forecast plays a major role in society. Currently weather forecasts
    are based on Numerical Weather Prediction (NWP) models that generate
    a representation of the atmospheric flow. Interactive visualization
    of geo-spatial data has been widely used in order to facilitate the
    analysis of NWP models. This paper presents a visualization system
    for the analysis of spatio-temporal patterns in short-term weather
    forecasts. For this purpose, we provide an interactive visualization
    interface that guides users from simple visual overviews to more
    advanced visualization techniques. Our solution presents multiple
    views that include a timeline with geo-referenced maps, an integrated
    webmap view, a forecast operation tool, a curve-pattern selector,
    spatial filters, and a linked meteogram. Two key contributions of
    this work are the timeline with geo-referenced maps and the curve-pattern
    selector. The latter provides novel functionality that allows users
    to specify and search for meaningful patterns in the data. The visual
    interface of our solution allows users to detect both possible weather
    trends and errors in the weather forecast model.We illustrate the
    usage of our solution with a series of case studies that were designed
    and validated in collaboration with domain experts.},
    doi = {10.1111/cgf.12650},
    event = {EuroVis 2015},
    images = {images/Diehl-2015-VAS.jpg},
    keywords = {weather forecasting, visual analysis, spatiotemporal data},
    location = {Cagliari, Italy},
    owner = {bruckner},
    pdf = {pdfs/Diehl-2015-VAS.pdf},
    thumbnails = {images/Diehl-2015-VAS.png},
    timestamp = {2015.06.08},
    youtube = {https://www.youtube.com/watch?v=hhQwsuXpHo8},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Karimov-2015-GVE,
    author = {Alexey Karimov and Gabriel Mistelbauer and Thomas Auzinger and Stefan Bruckner},
    title = {Guided Volume Editing based on Histogram Dissimilarity},
    journal = {Computer Graphics Forum},
    year = {2015},
    volume = {34},
    number = {3},
    pages = {91--100},
    month = may,
    abstract = {Segmentation of volumetric data is an important part of many analysis
    pipelines, but frequently requires manual inspection and correction.
    While plenty of volume editing techniques exist, it remains cumbersome
    and error-prone for the user to find and select appropriate regions
    for editing. We propose an approach to improve volume editing by
    detecting potential segmentation defects while considering the underlying
    structure of the object of interest. Our method is based on a novel
    histogram dissimilarity measure between individual regions, derived
    from structural information extracted from the initial segmentation.
    Based on this information, our interactive system guides the user
    towards potential defects, provides integrated tools for their inspection,
    and automatically generates suggestions for their resolution. We
    demonstrate that our approach can reduce interaction effort and supports
    the user in a comprehensive investigation for high-quality segmentations.},
    doi = {10.1111/cgf.12621},
    event = {EuroVis 2015},
    images = {images/Karimov-2015-GVE.jpg},
    keywords = {medical visualization, segmentation, volume editing, interaction},
    location = {Cagliari, Italy},
    owner = {bruckner},
    pdf = {pdfs/Karimov-2015-GVE.pdf},
    thumbnails = {images/Karimov-2015-GVE.png},
    timestamp = {2015.06.08},
    url = {http://www.cg.tuwien.ac.at/research/publications/2015/karimov-2015-HD/},
    youtube = {https://www.youtube.com/watch?v=zjTYkXTm_dM},
    }
    [PDF] [DOI] [Bibtex]
    @InProceedings{Mindek-2015-ASM,
    author = {Peter Mindek and Ladislav \v{C}mol{\'i}k and Ivan Viola and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Automatized Summarization of Multiplayer Games},
    booktitle = {Proceedings of SCCG 2015},
    year = {2015},
    pages = {93--100},
    month = apr,
    note = {SCCG 2015 Best Paper Award},
    abstract = {We present a novel method for creating automatized gameplay dramatization
    of multiplayer video games. The dramatization serves as a visual
    form of guidance through dynamic 3D scenes with multiple foci, typical
    for such games. Our goal is to convey interesting aspects of the
    gameplay by animated sequences creating a summary of events which
    occurred during the game. Our technique is based on processing many
    cameras, which we refer to as a flock of cameras, and events captured
    during the gameplay, which we organize into a so-called event graph.
    Each camera has a lifespan with a certain time interval and its parameters
    such as position or look-up vector are changing over time. Additionally,
    during its lifespan each camera is assigned an importance function,
    which is dependent on the significance of the structures that are
    being captured by the camera. The images captured by the cameras
    are composed into a single continuous video using a set of operators
    based on cinematographic effects. The sequence of operators is selected
    by traversing the event graph and looking for specific patterns corresponding
    to the respective operators. In this way, a large number of cameras
    can be processed to generate an informative visual story presenting
    the gameplay. Our compositing approach supports insets of camera
    views to account for several important cameras simultaneously. Additionally,
    we create seamless transitions between individual selected camera
    views in order to preserve temporal continuity, which helps the user
    to follow the virtual story of the gameplay.},
    doi = {10.1145/2788539.2788549},
    images = {images/Mindek-2015-ASM.jpg},
    keywords = {animation, storytelling, game visualization},
    location = {Smolenice, Slovakia},
    owner = {bruckner},
    pdf = {pdfs/Mindek-2015-ASM.pdf},
    thumbnails = {images/Mindek-2015-ASM.png},
    timestamp = {2015.06.08},
    url = {http://www.cg.tuwien.ac.at/research/publications/2015/mindek-2015-mc/},
    }

2014

    [PDF] [Bibtex]
    @PHDTHESIS {natali14thesis,
    author = "Mattia Natali",
    title = "Sketch-based Modelling and Conceptual Visualization of Geomorphological Processes for Interactive Scientific Communication",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2014",
    month = "September",
    abstract = "Throughout this dissertation, solutions for rapid digitalization of ideas will be defined.More precisely, the focus is on interactive scientific sketching and communication of geology, where theresult is a digital illustrative 3D model. Results are achieved through a sketch-based modellingapproach which gives the user a more natural and intuitive modelling process, hence leading to aquicker definition of a geological illustration. To be able to quickly externalize and communicate onesideas as a digital 3D model, can be of importance. For instance, students may profit from explanationssupported by interactive illustrations. Exchange of information and hypotheses between domain expertsis also a targeted situation in our work. Furthermore, illustrative models are frequently employed in business, when decisional meetings take place for convincing the management that a project is worth to be funded. An advantage of digital models is that they can be saved and they are easy to distribute. In contrast to 2D images or paper sketches, one can interact with digital 3D models, and they can be transferred on portable devices for easy access (for instance during geological field studies). Another advantage, compared to standard geological illustrations, is that if a model has been created with internal structures, it can be arbitrarily cut and inspected. Different solutions for different aspects of subsurface geology are presented in this dissertation. To express folding and faulting processes, a first modelling approach based on cross-sectional sketches is introduced. User defined textures can be associated to each layer, and can then be deformed with sketch strokes, for communicating layer properties such as rock type and grain size. A following contribution includes a simple and compact representation to model and visualize 3D stratigraphic models. With this representation, erosion and deposition offluvial systems are easy to specify and display. Ancient river channels and other geological features, which are present in the subsurface, can be accessed by means of a volumetric representation. Geological models are obtained and visualized by sequentially defining stratigraphic layers, where each layer represents a unique erosion or deposition event. Evolution of rivers and deltas is important for geologists when interpreting the stratigraphy of the subsurface, in particular because it changes the landscape morphology and because river deposits are potential hydrocarbon reservoirs. Time plays a fundamental role in geological processes. Animations are well suited for communicating temporal change and a contribution in this direction is also given. With the techniques developed in this thesis, it becomes possible to produce a range of geological scenarios. The focus is on enabling geologists tocreate their subsurface models by means of sketches, to quickly communicate concepts and ideasrather than detailed information. Although the proposed techniques are simple to use and requirelittle design effort, complex models can be realized. ",
    pdf = "pdfs/natali14thesis.pdf",
    images = "images/Natali2014Rapid0.png, images/Natali2014Sketch0.png,",
    thumbnails = "images/Natali2014Rapid0.png, images/Natali2014Sketch0.png,",
    isbn = "?? ",
    url = "https://bora.uib.no/handle/1956/8570",
    project = "geoillustrator"
    }
    [Bibtex]
    @MISC {Brambilla14Video,
    author = "Andrea Brambilla",
    title = "Video Visualization: An Overview",
    howpublished = "Trial lecture, University of Bergen",
    month = "November",
    year = "2014",
    abstract = "Videos are one of the most widespread media for collecting, communicating and archiving information. Nowadays, acquiring videos is a relatively straightforward process, and this explains their success in the context of entertainment, surveillance, sport events, and so on. On the other hand, watching and extracting information from a video stream is a lengthy process. Automatic techniques are only partially sucessful because of the intrinsic complexity of this kind of data. Video visualization is a growing research field which aims at easying the study of video data. It relies on both automatic techniques and user interaction, exploiting the best of both worlds. In this talk, I will introduce this field, focusing on its evolution from computer vision. I will discuss the main challenges and present an overview of the state-of-the-art. The talk will conclude with a discussion of the open problems and the expected future developments.",
    images = "images/Brambilla14Video.png",
    thumbnails = "images/Brambilla14Video.png",
    location = "Bergen, Norway",
    pres = "pdfs/Brambilla14Video.pptx"
    }
    [DOI] [Bibtex]
    @INCOLLECTION {RobertLaramee2014HSH,
    author = "Robert Laramee and Hamish Carr and Min Chen and Helwig Hauser and Lars Linsen and Klaus Mueller and Vijay Natarajan and Harald Obermaier and Ronald Peikert and Eugene Zhang",
    title = "Future Challenges and Unsolved Problems in Multi-field Visualization",
    booktitle = "Scientific Visualization: Uncertainty, Multifield, Biomedical, and  Scalable Visualization",
    publisher = "Springer",
    year = "2014",
    editor = "Min Chen and Hans Hagen and Charles D. Hansen and Christopher R.  Johnson and Arie E. Kaufman",
    series = "Mathematics and Visualization",
    chapter = "19",
    pages = "205-211",
    month = "sep",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    doi = "10.1007/978-1-4471-6497-5_19",
    keywords = "uncertainty, heuristics, problem solving",
    owner = "hausser",
    timestamp = "2015.02.06",
    isbn = "978-1-4471-6496-8",
    url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8"
    }
    [Bibtex]
    @PHDTHESIS {brambilla14thesis,
    author = "Andrea Brambilla",
    title = "Visibility-oriented Visualization Design for Flow Illustration",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2014",
    month = "December",
    abstract = "Flow phenomena are ubiquitous in our world and they affect many aspects of our daily life. For this reason, they are the subject of extensive studies in several research fields. In medicine, the blood flow through our vessels can reveal important information about cardiovascular diseases. The air flow around a vehicle and the motion of fluids in a combustion engine are examples of relevant flow phenomena in engineering disciplines. Meteorologists, climatologists and oceanographers are instead concerned with winds and water currents. Thanks to the recent advancements in computational fluid dynamics and to the increasing power of modern hardware, accurate simulations of flow phenomena are feasible nowadays. The evolution of multiple flow attributes, such as velocity, temperature and pressure, can be simulated over large spatial and temporal domains (4D). The amount of data generated by this process is massive, therefore visualization techniques are often adopted in order to ease the analysis phase. The overall goal is to convey information about the phenomena of interest through a suitable representation of the data at hand. Due to the multivariate and multidimensional nature of the data, visibility issues (such as cluttering and occlusion), represent a significant challenge. Flow visualization can greatly benefit from studying and addressing visibility issues already in the design phase. In this thesis we investigate and demonstrate the effectiveness of taking visibility management into account early in the design process. We apply this principle to three characteristic flow visualization scenarios: (1) The simultaneous visualization of multiple flow attributes. (2) The visual inspection of single and multiple integral surfaces. (3) The selection of seeding curves for constructing families of integral surfaces. Our techniques result in clutter- and occlusion-free visualizations, which effectively illustrate the key aspects of the flow behavior. For demonstration purposes, we have applied our approaches to a number of application cases. Additionally, we have discussed our visualization designs with domain experts. They showed a genuine interest in our work and provided insightful suggestions for future research directions.",
    images = "images/brambilla14thesis_0.png, images/brambilla14thesis_1.png,",
    thumbnails = "images/brambilla14thesis_0_thumb.png, images/brambilla14thesis_1_thumb.png,",
    isbn = "978-82-308-2753-6",
    url = "http://hdl.handle.net/1956/8961"
    }
    [PDF] [DOI] [Bibtex]
    @MISC {Hauser2014SIBGRAPI,
    author = "Helwig Hauser",
    title = "Interactive Visual Exploration and Analysis of Multi-Faceted Scientific Data",
    howpublished = "Invited talk at SIBGRAPI Conference on Graphics, Patterns and Images in Rio de Janeiro, Brazil",
    month = "August",
    year = "2014",
    abstract = "Invited talk at SIBGRAPI Conference on Graphics, Patterns and Images in Rio de Janeiro, Brazil",
    pdf = "pdfs/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up.pdf",
    images = "images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0003.jpg, images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0001.jpg, images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0001(2).jpg, images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0001(3).jpg, images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0001(4).jpg",
    thumbnails = "images/2014-08-30--Rio--SIBGRAPI-invited-talk--print-new-new-2up_Image_0003.jpg",
    location = "Rio de Janeiro, Brazil",
    doi = "10.1007/978-1-4471-6497-5_15"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2014BigData,
    author = "Helwig Hauser",
    title = "Big Data - a threat or an opportunity for our modern society?",
    howpublished = "Invited talk at the Alumni Event of the University of Bergen, Norway",
    month = "May",
    year = "2014",
    abstract = "Invited talk at the Alumni Event of the University of Bergen, Norway",
    pdf = "pdfs/2014-05-10--UiB-Alumni--BigDataTalkHH--print2up.pdf",
    images = "images/2014-05-10--UiB-Alumni--BigDataTalkHH--print2up_Image_0003.jpg",
    thumbnails = "images/2014-05-10--UiB-Alumni--BigDataTalkHH--print2up_Image_0003.jpg",
    location = "Bergen, Norway"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2014HiB,
    author = "Helwig Hauser",
    title = "Interactive Visual Analysis of Rich Scientific Data",
    howpublished = "Invited talk at the Bergen University College in Bergen, Norway",
    month = "November",
    year = "2014",
    abstract = "Invited talk at the Bergen University College in Bergen, Norway",
    pdf = "pdfs/2014-11-25--BergenHIB--InvitedTalk--print2up--web.pdf",
    images = "images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0002.jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0003.jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0005.jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0002(2).jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0009.jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0002(3).jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0009(2).jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0003(2).jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0007.jpg, images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0005(2).jpg",
    thumbnails = "images/2014-11-25--BergenHIB--InvitedTalk--print2up--web_Image_0002.jpg",
    location = "Bergen, Norway"
    }
    [Bibtex]
    @MISC {Brambilla14Visibility,
    author = "Andrea Brambilla",
    title = "Visibility Management in Integration-based Flow Visualization",
    howpublished = "Talk at the Department of Informatics, Systems and Communication, University of Milano - Bicocca",
    month = "June",
    year = "2014",
    abstract = "The analysis of flow phenomena holds an important role in several fields, such as engineering and medicine. Flow visualization techniques aim at easing the investigation process by depicting the flow data through graphical entities. Specifically, integration-based methods employ lines and surfaces in order to visualize the long-term behavior of fluid particles. In this talk, I will give a brief introduction to integration-based flow visualization, present its advantages and discuss its main limitations, i.e., cluttering and occlusion. I will then present my recent work addressing these limitations. Two projects will be described: (1) A selection strategy for integral surfaces, which aims at detecting a small number of highly informative integral surfaces. (2) A technique for easing the investigation and comparison of surface families, based on a 2D reformation process.",
    images = "images/Brambilla14Visualizing.png",
    thumbnails = "images/Brambilla14Visualizing.png",
    location = "Milan, Italy",
    pres = "pdfs/Brambilla14Visibility.pdf"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2014Dagstuhl,
    author = "Helwig Hauser",
    title = "Semi-abstract visualization of rich scientific data",
    howpublished = "Invited talk at the Dagstuhl 14231 Seminar on Scientific Visualization, Dagstuhl, Germany",
    month = "June",
    year = "2014",
    abstract = "Invited talk at the Dagstuhl 14231 Seminar on Scientific Visualization, Dagstuhl, Germany",
    pdf = "pdfs/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up.pdf",
    images = "images/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up_Image_0002(3).jpg, images/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up_Image_0002(2).jpg, images/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up_Image_0002.jpg, images/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up_Image_0008.jpg",
    thumbnails = "images/2014-06-06--Dagstuhl--SemiAbstractSciVis--print2up_Image_0002(3).jpg",
    location = "Dagstuhl, Germany"
    }
    [Bibtex]
    @ARTICLE {alsallakh2014visual,
    author = "Alsallakh, Bilal and Hanbury, Allan and Hauser, Helwig and Miksch, Silvia and Rauber, Andreas",
    title = "Visual methods for analyzing probabilistic classification data",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2014",
    volume = "20",
    number = "12",
    pages = "1703--1712",
    abstract = "Multi-class classifiers often compute scores for the classification samples describing probabilities to belong to different classes. In order to improve the performance of such classifiers, machine learning experts need to analyze classification results for a large number of labeled samples to find possible reasons for incorrect classification. Confusion matrices are widely used for this purpose. However, they provide no information about classification scores and features computed for the samples. We propose a set of integrated visual methods for analyzing the performance of probabilistic classifiers. Our methods provide insight into different aspects of the classification results for a large number of samples. One visualization emphasizes at which probabilities these samples were classified and how these probabilities correlate with classification error in terms of false positives and false negatives. Another view emphasizes the features of these samples and ranks them by their separation power between selected true and false classifications. We demonstrate the insight gained using our technique in a benchmarking classification dataset, and show how it enables improving classification performance by interactively defining and evaluating post-classification rules.",
    images = "images/alsallakh2014visual3.jpg, images/alsallakh2014visual1.jpg, images/alsallakh2014visual2.jpg",
    thumbnails = "images/alsallakh2014visual3.jpg",
    publisher = "IEEE"
    }
    [Bibtex]
    @ARTICLE {matkovic2014visual,
    author = "Matkovic, Kresimir and Gracanin, Denis and Splechtna, Rainer and Jelovic, Mario and Stehno, Benedikt and Hauser, Helwig and Purgathofer, Werner",
    title = "Visual analytics for complex engineering systems: Hybrid visual steering of simulation ensembles",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2014",
    volume = "20",
    number = "12",
    pages = "1803--1812",
    abstract = "In this paper we propose a novel approach to hybrid visual steering of simulation ensembles. A simulation ensemble is a collection of simulation runs of the same simulation model using different sets of control parameters. Complex engineering systems have very large parameter spaces so a naïve sampling can result in prohibitively large simulation ensembles. Interactive steering of simulation ensembles provides the means to select relevant points in a multi-dimensional parameter space (design of experiment). Interactive steering efficiently reduces the number of simulation runs needed by coupling simulation and visualization and allowing a user to request new simulations on the fly. As system complexity grows, a pure interactive solution is not always sufficient. The new approach of hybrid steering combines interactive visual steering with automatic optimization. Hybrid steering allows a domain expert to interactively (in a visualization) select data points in an iterative manner, approximate the values in a continuous region of the simulation space (by regression) and automatically find the “best� points in this continuous region based on the specified constraints and objectives (by optimization). We argue that with the full spectrum of optimization options, the steering process can be improved substantially. We describe an integrated system consisting of a simulation, a visualization, and an optimization component. We also describe typical tasks and propose an interactive analysis workflow for complex engineering systems. We demonstrate our approach on a case study from automotive industry, the optimization of a hydraulic circuit in a high pressure common rail Diesel injection system.",
    images = "images/matkovic2014visual1.jpg, images/matkovic2014visual2.jpg",
    thumbnails = "images/matkovic2014visual1.jpg",
    publisher = "IEEE"
    }
    [DOI] [VID] [Bibtex]
    @ARTICLE {Angelelli14Interactive,
    author = "Paolo Angelelli and Steffen Oeltze and Cagatay Turkay and Judit Haasz and Erlend Hodneland and Arvid Lundervold and Astri Johansen Lundervold and Bernhard Preim and Helwig Hauser",
    title = "Interactive Visual Analysis of Heterogeneous Cohort Study Data",
    journal = "Computer Graphics and Applications, IEEE",
    year = "2014",
    volume = "PP",
    number = "99",
    pages = "1-1",
    abstract = "Cohort studies are used in medicine to enable the study of medical hypotheses in large samples. Often, a large amount of heterogeneous data is acquired from many subjects. The analysis is usually hypothesis-driven, i.e., a specific subset of such data is studied to confirm or reject specific hypotheses. In this paper, we demonstrate how we enable the interactive visual exploration and analysis of such data, helping with the generation of new hypotheses and contributing to the process of validating them. We propose a data-cube based model which allows to handle partially overlapping data subsets during the interactive visualization. This model enables the seamless integration of the heterogeneous data, as well as the linking of spatial and non-spatial views on these data. We implemented this model in an application prototype, and used it to analyze data acquired in the context of a cohort study on cognitive aging. In this paper we present a case-study analysis of selected aspects of brain connectivity by using a prototype implementation of the presented model, to demonstrate its potential and flexibility.",
    vid = "vids/angelelli14CohortExplorer.wmv",
    images = "images/angelelli14Cohort.png",
    thumbnails = "images/angelelli14Cohort.png",
    doi = "10.1109/MCG.2014.40",
    url = "http://dx.doi.org/10.1109/MCG.2014.40"
    }
    [DOI] [Bibtex]
    @ARTICLE {turkay2014characterizing,
    author = "Turkay, Cagatay and Lex, Alexander and Streit, Marc and Pfister, Hanspeter and Hauser, Helwig",
    title = "Characterizing cancer subtypes using dual analysis in caleydo stratomex",
    journal = "Computer Graphics and Applications, IEEE",
    year = "2014",
    volume = "34",
    number = "2",
    pages = "38--47",
    abstract = "Dual analysis uses statistics to describe both the dimensions and rows of a high-dimensional dataset. Researchers have integrated it into StratomeX, a Caleydo view for cancer subtype analysis. In addition, significant-difference plots show the elements of a candidate subtype that differ significantly from other subtypes, thus letting analysts characterize subtypes. Analysts can also investigate how data samples relate to their assigned subtype and other groups. This approach lets them create well-defined subtypes based on statistical properties. Three case studies demonstrate the approach's utility, showing how it reproduced findings from a published subtype characterization.",
    images = "images/img_Page_08_Image_0001.jpg, images/img_Page_04_Image_0001.jpg",
    thumbnails = "images/img_Page_08_Image_0001.jpg",
    publisher = "IEEE",
    doi = "10.1109/MCG.2014.1"
    }
    [DOI] [VID] [Bibtex]
    @ARTICLE {Natali14Sketch,
    author = "Mattia Natali and Tore Grane Klausen and Daniel Patel",
    title = "Sketch-Based Modelling and Visualization of Geological Deposition",
    journal = "Computers \& Geosciences",
    year = "2014",
    volume = "67C",
    pages = "40--48",
    abstract = "We propose a method for sketching and visualizing geological models by sequentially defining stratigraphic layers, where each layer represents a unique erosion or deposition event. Evolution of rivers and deltas is important for geologists when interpreting the stratigraphy of the subsurface, in particular for hydrocarbon exploration. We illustratively visualize mountains, basins, lakes, rivers and deltas, and how they change the morphology of a terrain during their evolution. We present a compact representation of the model and a novel rendering algorithm that allows us to obtain an interactive and illustrative layer-cake visualization. A user study has been performed to evaluate our method.",
    vid = "vids/Natali2014Sketch.mp4",
    images = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
    thumbnails = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
    doi = "10.1016/j.cageo.2014.02.010",
    url = "http://www.sciencedirect.com/science/article/pii/S0098300414000508",
    project = "geoillustrator"
    }
    [Bibtex]
    @MISC {Brambilla14Visualizing,
    author = "Andrea Brambilla",
    title = "Visualizing the Long-term Behavior of 3D Fluid Flows",
    howpublished = "Presentation at the Konversatorium, Institute for Computer Graphics and Algorithm, TU Wien",
    month = "April",
    year = "2014",
    abstract = "The study of the long-term behavior of 3D fluid flows can provide useful insights into transport phenomena, which are of central importance in many fields, such as medicine and engineering. Such a study is normally based on the integration of the flow field. The resulting integral structures are indeed highly expressive, but their direct visualization often suffers from cluttering and occlusion issues. In this talk I will present my recent (and future) work addressing this problem. Three projects will be covered: (1) A seeding strategy for families of integral surfaces, which captures the predominant aspects of the long-term flow behavior. (2) A technique for easing the investigation and comparison of surface families, based on a 2D reformation process. (3) The work I am carrying out here at the TU, aimed at quantifying transport phenomena and depicting them using Sankey diagrams.",
    images = "images/Brambilla14Visualizing.png",
    thumbnails = "images/Brambilla14Visualizing.png",
    location = "Wien, Austria",
    url = "http://www.cg.tuwien.ac.at/courses/konversatorium/2014-04-25",
    pres = "pdfs/Brambilla14Visualizing.pdf"
    }
    [Bibtex]
    @ARTICLE {lemuzic2014ivm,
    author = "Mathieu Le Muzic and Julius Parulek and Anne-Kristin Stavrum and Ivan Viola",
    title = "Illustrative Visualization of Molecular Reactions using Omniscient Intelligence and Passive Agents ",
    journal = "Computer Graphics Forum",
    year = "2014",
    volume = "33",
    number = "3",
    pages = "141--150",
    month = "jun",
    abstract = "In this paper we propose a new type of a particle systems, tailored for illustrative visualization purposes, in particular for visualizing molecular reactions in biological networks. Previous visualizations of biochemical processes were exploiting the results of agent-based modeling. Such modeling aims at reproducing accurately the stochastic nature of molecular interactions. However, it is impossible to expect events of interest happening at a certain time and location, which is impractical for storytelling. To obtain the means of controlling molecular interactions, we propose to govern passive agents with an omniscient intelligence, instead of giving to the agents the freedom of initiating reaction autonomously. This makes it possible to generate illustrative animated stories that communicate the functioning of the molecular machinery. The rendering performance delivers for interactive framerates of massive amounts of data, based on the dynamic tessellation capabilities of modern graphics cards. Finally, we report an informal expert feedback we obtained from the potential users.",
    images = "images/Lemuzic14Illustrative.png, images/Lemuzic14Illustrative.png",
    thumbnails = "images/Lemuzic14Illustrative0_thumb.png, images/Lemuzic14Illustrative1_thumb.png",
    event = "EuroVis",
    url = "http://www.cg.tuwien.ac.at/research/publications/2014/lemuzic-2014-ivm/",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @INCOLLECTION {turkay2014computationally,
    author = "Turkay, Cagatay and Jeanquartier, Fleur and Holzinger, Andreas and Hauser, Helwig",
    title = "On computationally-enhanced visual analysis of heterogeneous data and its application in biomedical informatics",
    booktitle = "Interactive Knowledge Discovery and Data Mining in Biomedical Informatics",
    publisher = "Springer",
    year = "2014",
    pages = "117--140",
    abstract = "With the advance of new data acquisition and generation technologies, the biomedical domain is becoming increasingly data-driven. Thus, understanding the information in large and complex data sets has been in the focus of several research fields such as statistics, data mining, machine learning, and visualization. While the first three fields predominantly rely on computational power, visualization relies mainly on human perceptual and cognitive capabilities for extracting information. Data visualization, similar to Human–Computer Interaction, attempts an appropriate interaction between human and data to interactively exploit data sets. Specifically within the analysis of complex data sets, visualization researchers have integrated computational methods to enhance the interactive processes. In this state-of-the-art report, we investigate how such an integration is carried out. We study the related literature with respect to the underlying analytical tasks and methods of integration. In addition, we focus on how such methods are applied to the biomedical domain and present a concise overview within our taxonomy. Finally, we discuss some open problems and future challenges.",
    images = "images/img_Page_12_Image_0001.jpg, images/img_Page_12_Image_0002.jpg, images/img_Page_12_Image_0003.jpg",
    thumbnails = "images/img_Page_12_Image_0001.jpg",
    doi = "10.1007/978-3-662-43968-5_7)"
    }
    [PDF] [Bibtex]
    @MISC {LeMusic14Temporal,
    author = "Mathieu Le Muzic and Julius Parulek and Manuela Waldner and Ivan Viola",
    title = "Illustrative Visualization of Biochemical Processes Featuring Multiple Temporal Scales",
    howpublished = "Poster presented at the EG VCBM workshop 2014",
    month = "September",
    year = "2014",
    pdf = "pdfs/LeMusic14Temporal.pdf",
    images = "images/LeMuzic14Temporal.png",
    thumbnails = "images/LeMuzic14Temporal_thumb.png",
    location = "Wien, Austria",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @ARTICLE {turkay2014attribute,
    author = "Turkay, Cagatay and Slingsby, Aidan and Hauser, Helwig and Wood, Jo and Dykes, Jason",
    title = "Attribute signatures: Dynamic visual summaries for analyzing multivariate geographical data",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2014",
    volume = "20",
    number = "12",
    pages = "2033--2042",
    abstract = "The visual analysis of geographically referenced datasets with a large number of attributes is challenging due to the fact that the characteristics of the attributes are highly dependent upon the locations at which they are focussed, and the scale and time at which they are measured. Specialized interactive visual methods are required to help analysts in understanding the characteristics of the attributes when these multiple aspects are considered concurrently. Here, we develop attribute signatures-interactively crafted graphics that show the geographic variability of statistics of attributes through which the extent of dependency between the attributes and geography can be visually explored. We compute a number of statistical measures, which can also account for variations in time and scale, and use them as a basis for' our visualizations. We then employ different graphical configurations to show and compare both continuous and discrete variation of location and scale. Our methods allow variation in multiple statistical summaries of multiple attributes to be considered concurrently and geographically, as evidenced by examples in which the census geography of London and the wider UK are explored.",
    images = "images/img_Page_06_Image_0003.jpg, images/img_Page_01_Image_0002.jpg, images/img_Page_01_Image_0005.jpg, images/img_Page_07_Image_0003.jpg",
    thumbnails = "images/img_Page_06_Image_0003.jpg",
    publisher = "IEEE",
    doi = "10.1109/TVCG.2014.2346265"
    }
    [Bibtex]
    @MISC {Kingman14Integrating,
    author = "Pina Kingman and Anne-Kristin Stavrum and Ivan Viola and Helwig Hauser",
    title = "Integrating 2D and 3D Animation to Comprehensively Communicate Biology",
    howpublished = "Poster presented at the VizBi conference 2014",
    month = "March",
    year = "2014",
    abstract = "As research in cellular and molecular biology advances, so does the need to educated both the science research community and the general public. The former must be aware of developments in associated fields, the latter must be able to take responsibility for their own well-being. In both cases, we have a willing and capable audience, ready to delve deeper into the biological sciences. To exploit this opportunity, we need to research new and advanced visual language techniques to further improve communication. We are therefore investigating novel visual communication techniques to advance knowledge translation methods, focusing on effectively communicating abstract functional aspects of biological systems. To this end, we are creating several short animations, each one exploring different design solutions. These design solutions incorporate 2D motion graphics, information visualization, 3D animation, and can be applied to any biological story. In addition to our short animations, this research will culminate in a short film describing NAD-dependent DNA Repair, intended for the general public and researchers interested in these molecular systems.",
    images = "images/Kingman13Integrating.png",
    thumbnails = "images/Kingman13Integrating_thumb.jpg",
    location = "Heidelberg, Germany",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @INCOLLECTION {peikert2014comparison,
    author = "Ronald Peikert and Armin Pobitzer and Filip Sadlo and Benjamin Schindler",
    title = "A Comparison of Finite-Time and Finite-Size Lyapunov Exponents",
    booktitle = "Topological Methods in Data Analysis and Visualization III",
    publisher = "Springer International Publishing",
    year = "2014",
    editor = "Peer-Timo Bremer and Ingrid Hotz and Valerio Pascucci and Ronald Peikert",
    series = "Mathematics and Visualization",
    pages = "187--200",
    images = "images/peikert2014comparison.png",
    thumbnails = "images/peikert2014comparison_thumb.png",
    doi = "10.1007/978-3-319-04099-8_12",
    url = "http://dx.doi.org/10.1007/978-3-319-04099-8_12",
    isbn = "978-3-319-04098-1"
    }
    [Bibtex]
    @MISC {Kingman14PARP1,
    author = "Pina Kingman and Anne-Kristin Stavrum and Ivan Viola and Helwig Hauser",
    title = "PARP-1 Binds Damaged DNA",
    howpublished = "Poster presented at the VizBi conference 2014",
    month = "March",
    year = "2014",
    abstract = "This image is an excerpt from the animation entitled Negative charge and poly(ADP)-ribosylation: a scientific animation. The molecules where uploaded from the Protein Data Bank using the Embedded Python Molecular Viewer plug-in for Autodesk Maya (Johnson et al. 2001; Sanner et al. 1996). The scene was rendered using Maxon Cinema 4D and composited in Adobe Photoshop. Subsurface Scattering was chosen to give the molecules a translucent appearance. Two PARP-1 molecules are shown bound to damaged DNA (Coquelle and Glover 2012). This work has been carried out within the PhysioIllustration project (funded by NFR, project #218023).",
    images = "images/Kingman13PARP1.jpg",
    thumbnails = "images/Kingman13PARP1_thumb.jpg",
    location = "Heidelberg, Germany",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2014USP,
    author = "Helwig Hauser",
    title = "About Visualization in Bergen and Interactive Visual Analysis",
    howpublished = "Invited talk at Institute of Computing and Mathematical Sciences, University of São Paolo, in São Carlos, Brazil",
    month = "August",
    year = "2014",
    abstract = "Invited talk at Institute of Computing and Mathematical Sciences, University of São Paolo, in São Carlos, Brazil",
    pdf = "pdfs/2014-08-26--SaoCarlos--USP-inv-talk-print2up.pdf",
    images = "images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0001.jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0001(2).jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0001(3).jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0001(4).jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0002.jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0003.jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0003(2).jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0002(2).jpg, images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0002(3).jpg",
    thumbnails = "images/2014-08-26--SaoCarlos--USP-inv-talk-print2up_Image_0001.jpg",
    location = "São Carlos, Brazil"
    }
    [Bibtex]
    @MISC {Kingman14GenomeMaking,
    author = "Pina Kingman",
    title = "Our Resilient Genome: The Making of a Science Film",
    howpublished = "Presentation in the EG VCBM workshop 2014",
    month = "September",
    year = "2014",
    abstract = "Every single human cell has to fix 10,000 to 20,000 lesions in its DNA every day. Our cells are constantly exposed to many different types of threats that damage our genome. These lesions could cause mutations in our DNA, potentially leading to cancer and other diseases. With such continuous onslaught, how can our cells possibly protect our DNA from damage and mutations? This presentation will showcase the first public screening of a short film about DNA repair, which blends computer graphics and biology to communicate exciting up-and-coming research. This film was developed in conjunction with the Department of Informatics and the Department of Molecular Biology at the University of Bergen, and the Institute of Computer Graphics and Algorithms at the Vienna University of Technology. Along with a discussion on the visualisation process, I will also talk about the intersection between film and science that helps us communicate complex information.",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Wien, Austria",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2014NCE,
    author = "Helwig Hauser",
    title = "About Visual Computing",
    howpublished = "Invited talk at the NCE Subsea Theme Meeting on Visual Computing in Bergen, Norway",
    month = "April",
    year = "2014",
    abstract = "Invited talk at the NCE Subsea Theme Meeting on Visual Computing in Bergen, Norway",
    pdf = "pdfs/2014-04-08--VisCompTalk--HH--print2up.pdf",
    images = "images/2014-04-08--VisCompTalk--HH--print2up_Image_0004.jpg, images/2014-04-08--VisCompTalk--HH--print2up_Image_0006.jpg, images/2014-04-08--VisCompTalk--HH--print2up_Image_0010.jpg, images/2014-04-08--VisCompTalk--HH--print2up_Image_0002.jpg",
    thumbnails = "images/2014-04-08--VisCompTalk--HH--print2up_Image_0010.jpg",
    location = "Bergen, Norway"
    }
    [Bibtex]
    @MISC {Kingman14ResilientGenome,
    author = "Pina Kingman",
    title = "Our Resilient Genome",
    howpublished = "Talk in the Forshkningsdagene UNG 2014",
    month = "September",
    year = "2014",
    abstract = "Motivation: Make science research accessible to the public through film. Inspire and instil an interest in science and molecular biology. Story: The short animated film will describe the molecular pathways involved in single strand break DNA repair. Every single human cell has to repair an estimated 10,000-20,000 DNA lesion every day. DNA is constantly exposed to a variety of genotoxic events, leading to many different types of lesions. If the damage is not repaired, these lesions may lead to mutations that in turn lead to cancer and ageing. Your cells, however, have fine tuned mechanisms that maintain the integrity of our genome. This film describes one of those mechanisms. Length: About 3 minutes. Audience: We are aiming for the type of person who would attend a science film festival. We are thus assuming an interest in biology and medicine, at least a high-school degree (with the high probability of intending to continue to higher education), and a basic understanding of biology. Timeline: The film is currently in production and will be finished mid/late summer.",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Bergen, Norway",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {alsallakh2014visualizing,
    author = "Alsallakh, Bilal and Micallef, Luana and Aigner, Wolfgang and Hauser, Helwig and Miksch, Silvia and Rodgers, Peter",
    title = "Visualizing sets and set-typed data: State-of-the-art and future challenges",
    booktitle = "Eurographics conference on Visualization (EuroVis)--State of The Art Reports",
    year = "2014",
    pages = "1--21",
    abstract = "A variety of data analysis problems can be modelled by defining multiple sets over a collection of elements and analyzing the relations between these sets. Despite their simple concept, visualizing sets is a non-trivial problem due to the large number of possible relations between them. We provide a systematic overview of state-of-theart techniques for visualizing different kinds of set relations. We classify these techniques into 7 main categories according to the visual representations they use and the tasks they support. We compare the categories to provide guidance for choosing an appropriate technique for a given problem. Finally, we identify challenges in this area that need further research and propose possible directions to address with these challenges.",
    images = "images/img_Page_13_Image_0001.jpg",
    thumbnails = "images/img_Page_13_Image_0001.jpg",
    proceedings = "Eurographics conference on Visualization (EuroVis)--stars",
    doi = "dx.doi.org/10.2312/eurovisstar.20141170"
    }
    [PDF] [Bibtex]
    @ARTICLE {Natali14Rapid,
    author = "Mattia Natali and Julius Parulek and Daniel Patel",
    title = "Rapid Modelling of Interactive Geological Illustrations with Faults and Compaction",
    journal = "Proceedings of Spring Conference on Computer Graphics (SCCG)",
    year = "2014",
    abstract = "In this paper, we propose new methods for building geological illustrations and animations. We focus on allowing geologists to create their subsurface models by means of sketches, to quickly communicate concepts and ideas rather than detailed information. The result of our sketch-based modelling approach is a layer-cake volume representing geological phenomena, where each layer is rock material which has accumulated due to a user-defined depositional event. Internal geological structures can be inspected by different visualization techniques that we employ. Faulting and compaction of rock layers are important processes in geology. They can be modelled and visualized with our technique. Our representation supports non-planar faults that a user may define by means of sketches. Real-time illustrative animations are achieved by our GPU accelerated approach.",
    pdf = "pdfs/Natali14Rapid.pdf",
    images = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
    thumbnails = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
    url = "http://dx.doi.org/10.1145/2643188.2643201",
    project = "geoillustrator"
    }
    [PDF] [DOI] [YT] [Bibtex]
    @InProceedings{Solteszova-2014-VPS,
    author = {Veronika \v{S}olt{\'e}szov{\'a} and {\AA}smund Birkeland and Ivan Viola and Stefan Bruckner},
    title = {Visibility-Driven Processing of Streaming Volume Data},
    booktitle = {Proceedings of VCBM 2014},
    year = {2014},
    pages = {127--136},
    month = sep,
    note = {VCBM 2014 Best Paper Award},
    abstract = {In real-time volume data acquisition, such as 4D ultrasound, the raw
    data is challenging to visualize directly without additional processing.
    Noise removal and feature detection are common operations, but many
    methods are too costly to compute over the whole volume when dealing
    with live streamed data. In this paper, we propose a visibility-driven
    processing scheme for handling costly on-the-fly processing of volumetric
    data in real-time. In contrast to the traditional visualization pipeline,
    our scheme utilizes a fast computation of the potentially visible
    subset of voxels which significantly reduces the amount of data required
    to process. As filtering operations modify the data values which
    may affect their visibility, our method for visibility-mask generation
    ensures that the set of elements deemed visible does not change after
    processing. Our approach also exploits the visibility information
    for the storage of intermediate values when multiple operations are
    performed in sequence, and can therefore significantly reduce the
    memory overhead of longer filter pipelines. We provide a thorough
    technical evaluation of the approach and demonstrate it on several
    typical scenarios where on-the-fly processing is required.},
    doi = {10.2312/vcbm.20141198},
    event = {VCBM 2014},
    images = {images/Solteszova-2014-VPS.jpg},
    keywords = {ultrasound, visibility-driven processing, filtering},
    location = {Vienna, Austria},
    pdf = {pdfs/Solteszova-2014-VPS.pdf},
    thumbnails = {images/Solteszova-2014-VPS.png},
    youtube = {https://www.youtube.com/watch?v=WJgc6BX1qig},
    }
    [PDF] [DOI] [Bibtex]
    @InCollection{Amirkhanov-2014-HSH,
    author = {Artem Amirkhanov and Stefan Bruckner and Christoph Heinzl and Meister Eduard Gr{\"o}ller},
    title = {The Haunted Swamps of Heuristics: Uncertainty in Problem Solving},
    booktitle = {Scientific Visualization: Uncertainty, Multifield, Biomedical, and Scalable Visualization},
    publisher = {Springer},
    year = {2014},
    editor = {Min Chen and Hans Hagen and Charles D. Hansen and Christopher R. Johnson and Arie E. Kaufman},
    series = {Mathematics and Visualization},
    chapter = {5},
    pages = {51--60},
    month = {sep},
    abstract = {In scientific visualization the key task of research is the provision  of insight into a problem. Finding the solution to a problem may  be seen as finding a path through some rugged terrain which contains  mountains, chasms, swamps, and few flatlands. This path - an algorithm  discovered by the researcher - helps users to easily move around  this unknown area. If this way is a wide road paved with stones it  will be used for a long time by many travelers. However, a narrow  footpath leading through deep forests and deadly swamps will attract  only a few adventure seekers. There are many different paths with  different levels of comfort, length, and stability, which are uncertain  during the research process. Finding a systematic way to deal with  this uncertainty can greatly assist the search for a safe path which  is in our case the development of a suitable visualization algorithm  for a specific problem. In this work we will analyze the sources  of uncertainty in heuristically solving visualization problems and  will propose directions to handle these uncertainties.},
    doi = {10.1007/978-1-4471-6497-5_5},
    images = {images/Amirkhanov-2014-HSH.jpg},
    keywords = {uncertainty, heuristics, problem solving},
    owner = {bruckner},
    pdf = {pdfs/Amirkhanov-2014-HSH.pdf},
    thumbnails = {images/Amirkhanov-2014-HSH.png},
    timestamp = {2014.12.30},
    url = {http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8},
    }
    [PDF] [DOI] [Bibtex]
    @InProceedings{Angelelli-2014-LUP,
    author = {Paolo Angelelli and Sten Roar Snare and Siri Ann Nyrnes and Stefan Bruckner and Helwig Hauser and Lasse L{\o}vstakken},
    title = {Live Ultrasound-based Particle Visualization of Blood Flow in the Heart},
    booktitle = {Proceedings of SCCG 2014},
    year = {2014},
    pages = {42--49},
    month = may,
    abstract = {We introduce an integrated method for the acquisition, processing
    and visualization of live, in-vivo blood flow in the heart. The method
    is based on ultrasound imaging, using a plane wave acquisition acquisition
    protocol, which produces high frame rate ensemble data that are efficiently
    processed to extract directional flow information not previously
    available based on conventional Doppler imaging. These data are then
    visualized using a tailored pathlet-based visualization approach,
    to convey the slice-contained dynamic movement of the blood in the
    heart. This is especially important when imaging patients with possible
    congenital heart diseases, who typically exhibit complex flow patterns
    that are challenging to interpret. With this approach, it now is
    possible for the first time to achieve a real-time integration-based
    visualization of 2D blood flow aspects based on ultrasonic imaging.
    We demonstrate our solution in the context of selected cases of congenital
    heart diseases in neonates, showing how our technique allows for
    a more accurate and intuitive visualization of shunt flow and vortices.},
    doi = {10.1145/2643188.2643200},
    images = {images/Angelelli-2014-LUP.jpg},
    keywords = {ultrasound medical visualization, real-time visualization, blood flow visualization},
    pdf = {pdfs/Angelelli-2014-LUP.pdf},
    thumbnails = {images/Angelelli-2014-LUP.png},
    url = {http://dx.doi.org/10.1145/2643188.2643200},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Kolesar-2014-IIP,
    author = {Ivan Kolesar and Julius Parulek and Ivan Viola and Stefan Bruckner and Anne-Kristin Stavrum and Helwig Hauser},
    title = {Interactively Illustrating Polymerization using Three-level Model Fusion},
    journal = {BMC Bioinformatics},
    year = {2014},
    volume = {15},
    pages = {345},
    month = oct,
    abstract = {Research in cell biology is steadily contributing new knowledge about
    many aspects of physiological processes, both with respect to the
    involved molecular structures as well as their related function.
    Illustrations of the spatio-temporal development of such processes
    are not only used in biomedical education, but also can serve scientists
    as an additional platform for in-silico experiments. Results In this
    paper, we contribute a new, three-level modeling approach to illustrate
    physiological processes from the class of polymerization at different
    time scales. We integrate physical and empirical modeling, according
    to which approach best suits the different involved levels of detail,
    and we additionally enable a form of interactive steering, while
    the process is illustrated. We demonstrate the suitability of our
    approach in the context of several polymerization processes and report
    from a first evaluation with domain experts. Conclusion We conclude
    that our approach provides a new, hybrid modeling approach for illustrating
    the process of emergence in physiology, embedded in a densely filled
    environment. Our approach of a complementary fusion of three systems
    combines the strong points from the different modeling approaches
    and is capable to bridge different spatial and temporal scales.},
    doi = {10.1186/1471-2105-15-345},
    images = {images/Kolesar-2014-IIP.jpg},
    keywords = {biochemical visualization, L-system modeling, multi-agent modeling, visualization of physiology, polymerization},
    owner = {bruckner},
    pdf = {pdfs/Kolesar-2014-IIP.pdf},
    project = {physioillustration},
    thumbnails = {images/Kolesar-2014-IIP.png},
    timestamp = {2014.12.29},
    url = {http://www.ii.uib.no/vis/projects/physioillustration/research/interactive-molecular-illustration.html},
    youtube = {https://www.youtube.com/watch?v=iMl5nDicmhg},
    }
    [PDF] [VID] [Bibtex]
    @InProceedings{Kolesar-2014-IPT,
    author = {Ivan Kolesar and Julius Parulek and Ivan Viola and Stefan Bruckner and Anne-Kristin Stavrum and Helwig Hauser},
    title = {Illustrating Polymerization using Three-level Model Fusion},
    booktitle = {Proceedings of IEEE BioVis 2014},
    year = {2014},
    month = aug,
    abstract = {Research in cell biology is steadily contributing new knowledge about
    many different aspects of physiological processes like polymerization,
    both with respect to the involved molecular structures as well as
    their related function. Illustrations of the spatio-temporal development
    of such processes are not only used in biomedical education, but
    also can serve scientists as an additional platform for in-silico
    experiments. In this paper, we contribute a new, three-level modeling
    approach to illustrate physiological processes from the class of
    polymerization at different time scales. We integrate physical and
    empirical modeling, according to which approach suits the different
    involved levels of detail best, and we additionally enable a simple
    form of interactive steering while the process is illustrated. We
    demonstrate the suitability of our approach in the context of several
    polymerization processes and report from a first evaluation with
    domain experts.},
    images = {images/Kolesar-2014-IPT.jpg},
    keywords = {biochemical visualization, L-system modeling, multi-agent modeling, visualization of physiology, polymerization},
    owner = {bruckner},
    pdf = {pdfs/Kolesar-2014-IPT.pdf},
    project = {physioillustration},
    thumbnails = {images/Kolesar-2014-IPT.png},
    timestamp = {2014.12.29},
    vid = {vids/Kolesar14Polymers.mp4},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Mindek-2014-MSS,
    author = {Peter Mindek and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Managing Spatial Selections with Contextual Snapshots},
    journal = {Computer Graphics Forum},
    year = {2014},
    volume = {33},
    number = {8},
    pages = {132--144},
    month = dec,
    abstract = {Spatial selections are a ubiquitous concept in visualization. By localizing
    particular features, they can be analysed and compared in different
    views. However, the semantics of such selections often depend on
    specific parameter settings and it can be difficult to reconstruct
    them without additional information. In this paper, we present the
    concept of contextual snapshots as an effective means for managing
    spatial selections in visualized data. The selections are automatically
    associated with the context in which they have been created. Contextual
    snapshots can also be used as the basis for interactive integrated
    and linked views, which enable in-place investigation and comparison
    of multiple visual representations of data. Our approach is implemented
    as a flexible toolkit with well-defined interfaces for integration
    into existing systems. We demonstrate the power and generality of
    our techniques by applying them to several distinct scenarios such
    as the visualization of simulation data, the analysis of historical
    documents and the display of anatomical data.},
    doi = {10.1111/cgf.12406},
    images = {images/Mindek-2014-MSS.jpg},
    keywords = {interaction, visual analytics, spatial selections, annotations},
    pdf = {pdfs/Mindek-2014-MSS.pdf},
    thumbnails = {images/Mindek-2014-MSS.png},
    url = {http://www.cg.tuwien.ac.at/downloads/csl/},
    youtube = {https://www.youtube.com/watch?v=rxEf-Okp8Xo},
    }
    [PDF] [DOI] [Bibtex]
    @Article{Parulek-2014-CLV,
    author = {Julius Parulek and Daniel J{\"o}nsson and Timo Ropinski and Stefan Bruckner and Anders Ynnerman and Ivan Viola},
    title = {Continuous Levels-of-Detail and Visual Abstraction for Seamless Molecular Visualization},
    journal = {Computer Graphics Forum},
    year = {2014},
    volume = {33},
    number = {6},
    pages = {276--287},
    month = sep,
    issn = {1467-8659},
    abstract = {Molecular visualization is often challenged with rendering of large
    molecular structures in real time. We introduce a novel approach
    that enables us to show even large protein complexes. Our method
    is based on the level-of-detail concept, where we exploit three different
    abstractions combined in one visualization. Firstly, molecular surface
    abstraction exploits three different surfaces, solvent-excluded surface
    (SES), Gaussian kernels and van der Waals spheres, combined as one
    surface by linear interpolation. Secondly, we introduce three shading
    abstraction levels and a method for creating seamless transitions
    between these representations. The SES representation with full shading
    and added contours stands in focus while on the other side a sphere
    representation of a cluster of atoms with constant shading and without
    contours provide the context. Thirdly, we propose a hierarchical
    abstraction based on a set of clusters formed on molecular atoms.
    All three abstraction models are driven by one importance function
    classifying the scene into the near-, mid- and far-field. Moreover,
    we introduce a methodology to render the entire molecule directly
    using the A-buffer technique, which further improves the performance.
    The rendering performance is evaluated on series of molecules of
    varying atom counts.},
    doi = {10.1111/cgf.12349},
    images = {images/Parulek-2014-CLV.jpg},
    keywords = {level of detail algorithms, implicit surfaces, clustering, scientific visualization},
    pdf = {pdfs/Parulek-2014-CLV.pdf},
    project = {physioillustration},
    thumbnails = {images/Parulek-2014-CLV.png},
    }
    [PDF] [DOI] [Bibtex]
    @InCollection{Pfister-2014-VIC,
    author = {Hanspeter Pfister and Verena Kaynig and Charl P. Botha and Stefan Bruckner and Vincent J. Dercksen and Hans-Christian Hege and Jos B.T.M. Roerdink},
    title = {Visualization in Connectomics},
    booktitle = {Scientific Visualization: Uncertainty, Multifield, Biomedical, and Scalable Visualization},
    publisher = {Springer},
    year = {2014},
    editor = {Min Chen and Hans Hagen and Charles D. Hansen and Christopher R. Johnson and Arie E. Kaufman},
    series = {Mathematics and Visualization},
    chapter = {21},
    pages = {221--245},
    month = sep,
    abstract = {Connectomics is a branch of neuroscience that attempts to create a
    connectome, i.e., a completemap of the neuronal system and all connections
    between neuronal structures. This representation can be used to understand
    how functional brain states emerge from their underlying anatomical
    structures and how dysfunction and neuronal diseases arise. We review
    the current state-of-the-art of visualization and image processing
    techniques in the field of connectomics and describe a number of
    challenges. After a brief summary of the biological background and
    an overview of relevant imaging modalities, we review current techniques
    to extract connectivit},
    doi = {10.1007/978-1-4471-6497-5_21},
    images = {images/Pfister-2014-VIC.jpg},
    keywords = {connectomics, neuroscience, visualization, imaging},
    owner = {bruckner},
    pdf = {pdfs/Pfister-2014-VIC.pdf},
    thumbnails = {images/Pfister-2014-VIC.png},
    timestamp = {2014.12.30},
    url = {http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Rautek-2014-VSI,
    author = {Peter Rautek and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger},
    title = {ViSlang: A System for Interpreted Domain-Specific Languages for Scientific Visualization},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2014},
    volume = {20},
    number = {12},
    pages = {2388--2396},
    month = dec,
    abstract = {Researchers from many domains use scientific visualization in their
    daily practice. Existing implementations of algorithms usually come
    with a graphical user interface (high-level interface), or as software
    library or source code (low-level interface). In this paper we present
    a system that integrates domain-specific languages (DSLs) and facilitates
    the creation of new DSLs. DSLs provide an effective interface for
    domain scientists avoiding the difficulties involved with low-level
    interfaces and at the same time offering more flexibility than high-level
    interfaces. We describe the design and implementation of ViSlang,
    an interpreted language specifically tailored for scientific visualization.
    A major contribution of our design is the extensibility of the ViSlang
    language. Novel DSLs that are tailored to the problems of the domain
    can be created and integrated into ViSlang. We show that our approach
    can be added to existing user interfaces to increase the flexibility
    for expert users on demand, but at the same time does not interfere
    with the user experience of novice users. To demonstrate the flexibility
    of our approach we present new DSLs for volume processing, querying
    and visualization. We report the implementation effort for new DSLs
    and compare our approach with Matlab and Python implementations in
    terms of run-time performance.},
    doi = {10.1109/TVCG.2014.2346318},
    event = {IEEE VIS 2014},
    images = {images/Rautek-2014-VSI.jpg},
    keywords = {domain-specific languages, volume visualization, volume visualization framework},
    location = {Paris, France},
    pdf = {pdfs/Rautek-2014-VSI.pdf},
    thumbnails = {images/Rautek-2014-VSI.png},
    url = {http://vcc.kaust.edu.sa/Pages/Pub-ViSlang-Sys-Int-Dom-Spe-Lang-SC.aspx},
    youtube = {https://www.youtube.com/watch?v=DbWazwyMRNw},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @InProceedings{Schmidt-2014-YMC,
    author = {Johanna Schmidt and Reinhold Preiner and Thomas Auzinger and Michael Wimmer and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {YMCA - Your Mesh Comparison Application},
    booktitle = {Proceedings of IEEE VAST 2014},
    year = {2014},
    pages = {153--62},
    month = nov,
    abstract = {Polygonal meshes can be created in several different ways. In this
    paper we focus on the reconstruction of meshes from point clouds,
    which are sets of points in 3D. Several algorithms that tackle this
    task already exist, but they have different benefits and drawbacks,
    which leads to a large number of possible reconstruction results
    (i.e., meshes). The evaluation of those techniques requires extensive
    comparisons between different meshes which is up to now done by either
    placing images of rendered meshes side-by-side, or by encoding differences
    by heat maps. A major drawback of both approaches is that they do
    not scale well with the number of meshes. This paper introduces a
    new comparative visual analysis technique for 3D meshes which enables
    the simultaneous comparison of several meshes and allows for the
    interactive exploration of their differences. Our approach gives
    an overview of the differences of the input meshes in a 2D view.
    By selecting certain areas of interest, the user can switch to a
    3D representation and explore the spatial differences in detail.
    To inspect local variations, we provide a magic lens tool in 3D.
    The location and size of the lens provide further information on
    the variations of the reconstructions in the selected area. With
    our comparative visualization approach, differences between several
    mesh reconstruction algorithms can be easily localized and inspected.},
    doi = {10.1109/VAST.2014.7042491},
    event = {IEEE VIS 2014},
    images = {images/Schmidt-2014-YMC.jpg},
    keywords = {visual analysis, comparative visualization, 3D data exploration, focus+context, mesh comparison},
    location = {Paris, France},
    pdf = {pdfs/Schmidt-2014-YMC.pdf},
    proceedings = {Proceedings of IEEE VAST 2014},
    thumbnails = {images/Schmidt-2014-YMC.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2014/ymca/},
    youtube = {https://www.youtube.com/watch?v=1s-AmFCQRzM},
    }
    [PDF] [DOI] [Bibtex]
    @Article{Sedlmair-2014-VPS,
    author = {Michael Sedlmair and Christoph Heinzl and Stefan Bruckner and Harald Piringer and Torsten M{\"o}ller},
    title = {Visual Parameter Space Analysis: A Conceptual Framework},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2014},
    volume = {20},
    number = {12},
    pages = {2161--2170},
    month = dec,
    abstract = {Various case studies in different application domains have shown the
    great potential of visual parameter space analysis to support validating
    and using simulation models. In order to guide and systematize research
    endeavors in this area, we provide a conceptual framework for visual
    parameter space analysis problems. The framework is based on our
    own experience and a structured analysis of the visualization literature.
    It contains three major components: (1) a data flow model that helps
    to abstractly describe visual parameter space analysis problems independent
    of their application domain; (2) a set of four navigation strategies
    of how parameter space analysis can be supported by visualization
    tools; and (3) a characterization of six analysis tasks. Based on
    our framework, we analyze and classify the current body of literature,
    and identify three open research gaps in visual parameter space analysis.
    The framework and its discussion are meant to support visualization
    designers and researchers in characterizing parameter space analysis
    problems and to guide their design and evaluation processes.},
    doi = {10.1109/TVCG.2014.2346321},
    event = {IEEE VIS 2014},
    images = {images/Sedlmair-2014-VPS.jpg},
    keywords = {parameter space analysis, input-output model, simulation, task characterization, literature analysis},
    location = {Paris, France},
    pdf = {pdfs/Sedlmair-2014-VPS.pdf},
    thumbnails = {images/Sedlmair-2014-VPS.png},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @InProceedings{Swoboda-2014-VQA,
    author = {Nicolas Swoboda and Judith Moosburner and Stefan Bruckner and Jai Y. Yu and Barry J. Dickson and Katja B{\"u}hler},
    title = {Visual and Quantitative Analysis of Higher Order Arborization Overlaps for Neural Circuit Research},
    booktitle = {Proceedings of VCBM 2014},
    year = {2014},
    pages = {107--116},
    month = sep,
    note = {VCBM 2014 Best Paper Honorable Mention},
    abstract = {Neuroscientists investigate neural circuits in the brain of the common
    fruit fly Drosophila melanogaster to discover how complex behavior
    is generated. Hypothesis building on potential connections between
    individual neurons is an essential step in the discovery of circuits
    that govern a specific behavior. Overlaps of arborizations of two
    or more neurons indicate a potential anatomical connection, i.e.
    the presence of joint synapses responsible for signal transmission
    between neurons. Obviously, the number of higher order overlaps (i.e.
    overlaps of three and more arborizations) increases exponentially
    with the number of neurons under investigation making it almost impossible
    to precompute quantitative information for all possible combinations.
    Thus, existing solutions are restricted to pairwise comparison of
    overlaps as they are relying on precomputed overlap quantification.
    Analyzing overlaps by visual inspection of more than two arborizations
    in 2D sections or in 3D is impeded by visual clutter or occlusion.
    This work contributes a novel tool that complements existing methods
    for potential connectivity exploration by providing for the first
    time the possibility to compute and visualize higher order arborization
    overlaps on the fly and to interactively explore this information
    in its spatial anatomical context and on a quantitative level. Qualitative
    evaluation with neuroscientists and non-expert users demonstrated
    the utility and usability of the tool.},
    doi = {10.2312/vcbm.20141189},
    event = {VCBM 2014},
    images = {images/Swoboda-2014-VQA.jpg},
    keywords = {visual analysis, neurobiology},
    location = {Vienna, Austria},
    pdf = {pdfs/Swoboda-2014-VQA.pdf},
    thumbnails = {images/Swoboda-2014-VQA.png},
    youtube = {https://www.youtube.com/watch?v=iW2iVppPnsE},
    }
    [PDF] [DOI] [Bibtex]
    @InProceedings{Waldner-2014-GHI,
    author = {Manuela Waldner and Stefan Bruckner and Ivan Viola},
    title = {Graphical Histories of Information Foraging},
    booktitle = {Proceedings of NordiCHI 2014},
    year = {2014},
    pages = {295--304},
    month = oct,
    abstract = {During information foraging, knowledge workers iteratively seek, filter,
    read, and extract information. When using multiple information sources
    and different applications for information processing, re-examination
    of activities for validation of previous decisions or re-discovery
    of previously used information sources is challenging. In this paper,
    we present a novel representation of cross-application histories
    to support recall of past operations and re-discovery of information
    resources. Our graphical history consists of a cross-scale visualization
    combining an overview node-link diagram of used desktop resources
    with nested (animated) snapshot sequences, based on a recording of
    the visual screen output during the users’ desktop work. This representation
    makes key elements of the users’ tasks visually stand out, while
    exploiting the power of visual memory to recover subtle details of
    their activities. In a preliminary study, users found our graphical
    history helpful to recall details of an information foraging task
    and commented positively on the ability to expand overview nodes
    into snapshot and video sequences.},
    doi = {10.1145/2639189.2641202},
    images = {images/Waldner-2014-GHI.jpg},
    keywords = {interaction history, graph visualization, provenance},
    owner = {bruckner},
    pdf = {pdfs/Waldner-2014-GHI.pdf},
    thumbnails = {images/Waldner-2014-GHI.png},
    timestamp = {2014.12.30},
    url = {http://www.cg.tuwien.ac.at/research/publications/2014/waldner-2014-ghi/},
    }

2013

    [DOI] [Bibtex]
    @ARTICLE {Lidal13Geological,
    author = "Endre M. Lidal and Mattia Natali and Daniel Patel and Helwig Hauser and Ivan Viola",
    title = "Geological storytelling",
    journal = "Computers \& Graphics",
    year = "2013",
    volume = "37",
    number = "5",
    pages = "445--459 ",
    abstract = "Developing structural geological models from exploratory subsea imaging is difficult and an ill-posed process. The structural geological processes that take place in the subsurface are both complex and time-dependent. We present Geological Storytelling, a novel graphical system for performing rapid and expressive geomodeling. Geologists can convey geological stories that externalize both their model and the reasoning process behind it through our simple, yet expressive sketch-based, flip-over canvases. This rapid modeling interface makes it easy to construct a large variety of geological stories, and our story tree concept facilitates easy management and the exploration of these alternatives. The stories are then animated and the geologists can examine and compare them to identify the most plausible models. Finally, the geological stories can be presented as illustrative animations of automatically synthesized 3D models, which efficiently communicate the complex geological evolution to non-experts and decision makers. Geological storytelling provides a complete pipeline from the ideas and knowledge in the mind of the geologist, through externalized artifacts specialized for discussion and knowledge dissemination among peer-experts, to automatically rendered illustrative 3D animations for communication to lay audience. We have developed geological storytelling in collaboration with domain experts that work with the modeling challenges on a daily basis. For evaluation, we have developed a geological storytelling prototype and presented it to experts and academics from the geosciences. In their feedback, they acknowledge that the rapid and expressive sketching of stories can make them explore more alternatives and that the 3D illustrative animations assist in communicating their models.",
    images = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
    thumbnails = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
    issn = "0097-8493",
    doi = "http://dx.doi.org/10.1016/j.cag.2013.01.010",
    url = "http://www.sciencedirect.com/science/article/pii/S0097849313000125",
    keywords = "Sketch-based modeling; Externalization of mental processes; Storytelling; 3D model synthesis; Animation; Alternatives exploration; Geology; Structural geological models",
    project = "geoillustrator"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2013IHCI,
    author = "Helwig Hauser",
    title = "Integrating Interactive and Computational Analysis in Visual Analytics",
    howpublished = "Keynote talk at IHCI 2013 in Prague, Czech Republic.",
    month = "July",
    year = "2013",
    abstract = "Keynote talk at IHCI 2013 in Prague, Czech Republic.",
    pdf = "pdfs/2013-07-22--Prague--IHCI--Keynote--IVA--print2up.pdf",
    images = "images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(2).jpg, images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(3).jpg, images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(4).jpg, images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(5).jpg, images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(6).jpg, images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0003.jpg",
    thumbnails = "images/2013-07-22--Prague--IHCI--Keynote--IVA--print2up_Image_0001(2).jpg"
    }
    [DOI] [Bibtex]
    @ARTICLE {Hauser13GuestEditors,
    author = "Helwig Hauser and Stephen Kobourov and Huamin Qu",
    title = "Guest Editors' Introduction: Special Section on the IEEE Pacific Visualization Symposium 2012",
    journal = "IEEE Transactions on Visualization and Computer Graphics",
    year = "2013",
    volume = "19",
    number = "6",
    pages = "898-899",
    images = "images/Gno_thumb.png",
    thumbnails = "images/no_thumb.png",
    issn = "1077-2626",
    url = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2013.70",
    doi = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2013.70",
    publisher = "IEEE Computer Society",
    address = "Los Alamitos, CA, USA"
    }
    [PDF] [DOI] [Bibtex]
    @ARTICLE {Kehrer13VisualizationAnd,
    author = "Johannes Kehrer and Helwig Hauser",
    title = "Visualization and Visual Analysis of Multi-faceted Scientific Data: a Survey",
    journal = "IEEE Transactions on Visualization and Computer Graphics",
    year = "2013",
    volume = "19",
    number = "3",
    pages = "495-513",
    abstract = "Visualization and visual analysis play important roles in exploring, analyzing and presenting scientific data. In many disciplines, data and model scenarios are becoming multi-faceted: data are often spatio-temporal and multi-variate; they stem from different data sources (multi-modal data), from multiple simulation runs (multi-run/ensemble data), or from multi-physics simulations of interacting phenomena (multi-model data resulting from coupled simulation models). Also, data can be of different dimensionality or structured on various types of grids that need to be related or fused in the visualization. This heterogeneity of data characteristics presents new opportunities as well as technical challenges for visualization research. Visualization and interaction techniques are thus often combined with computational analysis. In this survey, we study existing methods for visualization and interactive visual analysis of multi-faceted scientific data. Based on a thorough literature review, a categorization of approaches is proposed. We cover a wide range of fields and discuss to which degree the different challenges are matched with existing solutions for visualization and visual analysis. This leads to conclusions with respect to promising research directions, for instance, to pursue new solutions for multi-run and multi-model data as well as techniques that support a multitude of facets.",
    pdf = "pdfs/Kehrer13VisualizationAnd.pdf",
    images = "images/Kehrer13VisualizationAnd01.png",
    thumbnails = "images/Kehrer13VisualizationAnd01_thumb.png",
    issn = "1077-2626",
    doi = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2012.110",
    publisher = "IEEE Computer Society",
    address = "Los Alamitos, CA, USA"
    }
    [PDF] [Bibtex]
    @ARTICLE {Parulek13Fast,
    author = "Julius Parulek and Andrea Brambilla",
    title = "Fast Blending Scheme for Molecular Surface Representation",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2013",
    pages = "2653--2662",
    month = "Dec.",
    abstract = "Representation of molecular surfaces is a well established way to study the interaction of molecules. The state-of-theart molecular representation is the SES model, which provides a detailed surface visualization. Nevertheless, it is computationally expensive, so the less accurate Gaussian model is traditionally preferred. We introduce a novel surface representation that resembles the SES and approaches the rendering performance of the Gaussian model. Our technique is based on the iterative blending of implicit functions and avoids any pre-computation. Additionally, we propose a GPU-based ray-casting algorithm that efficiently visualize our molecular representation. A qualitative and quantitative comparison of our model with respect to the Gaussian and SES models is presented. As showcased in the paper, our technique is a valid and appealing alternative to the Gaussian representation. This is especially relevant in all the applications where the cost of the SES is prohibitive.",
    pdf = "pdfs/Parulek13Fast.pdf",
    images = "images/Parulek13Fast01.png, images/Parulek13Fast02.png",
    thumbnails = "images/Parulek13Fast01_thumb.png, images/Parulek13Fast02_thumb.png",
    event = "Vis2013",
    project = "physioillustration",
    extra = "extra/Parulek13Fast_code.pdf"
    }
    [PDF] [Bibtex]
    @PHDTHESIS {birkeland13thesis,
    author = "{\AA}smund Rognerud Birkeland",
    title = "Ultrasonic Vessel Visualization: From Extraction to Perception",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2013",
    month = "March",
    abstract = "Ultrasound is one of the most frequently used imaging modalities in modern medicine. The high versatility and availability of ultrasound workstations is applied in various medical scenarios, such as diagnosis, treatment planning, intra-operative imaging, and more. Modern ultrasound workstations provide live imaging of anatomical structures, as well as physiological processes, such as blood flow. However, the imaging technique have a high presence of noise, a small scan sector, and are much affected by attenuation artefacts. Thus, traditional techniques for segmentation and visualization are not applicable to ultrasound data. In this theses, we present our latest advancements in segmentation and visualization techniques, tailored specifically for the characteristics of ultrasound data. We present new methods for interactive vessel segmentation for both 3D freehand and 4D ultrasound. By directly involving the examiner in the segmentation approach as well as combining data from different probe viewpoints, we are able to obtain 3D models of blood vessels rapidly and robustly. With the ability of robust vessel extraction, we introduce novel visualization techniques which utilize the previously acquired 3D vessel models. For anatomical imaging, we present a new physics-based approach for volume clipping, enhanced slice rendering and even defining curved Couinaud-surfaces. The technique creates a deformable membrane to adapt to structures in the underlying data, defined either by predefined segmentation, iso-values, or other data attributes. For functional imaging, medical ultrasound can use the Doppler principle to image blood flow. However, Doppler ultrasound only measures a projected velocity magnitude of the data. In this thesis, we present a technique that uses the direction of the blood vessels in order to reconstruct 3D blood flow from Doppler ultrasound. By extending Doppler ultrasound with this directional information, we are able to apply traditional flow visualization techniques for displaying the blood flow. Finally, we investigated the usage of moving particles as a means to depict velocity in flow visualization. Based on a series of studies targeted for motion perception, we present a new compensation model to correct for distortions in the human visual system. This model can help users to make a more consistent estimation of velocities from evaluating the motion of particles. ",
    pdf = "pdfs/birkeland13thesis.pdf",
    images = "images/birkeland13thesis.png",
    thumbnails = "images/birkeland13thesis_thumb.png",
    isbn = "?? ",
    project = "illustrasound, medviz, illvis"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2013VISU,
    author = "Helwig Hauser",
    title = "Interactive Visual Analysis of Scientific Data",
    howpublished = "Keynote talk at VISU 2013 in Paris, France",
    month = "November",
    year = "2013",
    abstract = "Keynote talk at VISU 2013 in Paris, France",
    pdf = "pdfs/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web.pdf",
    images = "images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0003.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0006.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0002.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0002(2).jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0010.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0008.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0009.jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0002(3).jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0002(4).jpg, images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0006(2).jpg",
    thumbnails = "images/2013-11-06--Paris--Visu2013--SciDataIVA--print2up--web_Image_0003.jpg",
    location = "Paris, France"
    }
    [Bibtex]
    @MISC {Kolesar13HumanPhysiology,
    author = "Ivan Kolesar",
    title = "Approaches for Visualizing Human Physiology",
    howpublished = "Presentation in the VisBio 2013",
    month = "September",
    year = "2013",
    abstract = "Physiology is scientific study of function in living systems. All in all, we presents several visual abstractions used to communicate physiological processes through different functional human systems in different scales from molecules to whole human body. However there are still several challenges for visualizing multi-scale physiological processes.",
    images = "images/no_thumb.png",
    thumbnails = "images/Kolesar13HumanPhysiology.jpg",
    location = "Bergen, Norway",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @PHDTHESIS {turkay13thesis,
    author = "Cagatay Turkay",
    title = "Integrating Computational Tools in Interactive and Visual Methods for Enhancing High-dimensional Data and Cluster Analysis",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2013",
    month = "November",
    abstract = "With the advance of new data acquisition and generation technologies, our society is becoming increasingly information-driven. The datasets are getting larger and more complex as new technologies emerge and they are posing new challenges to the analysts who are trying to build an understanding of them. Automated computational approaches and interactive visual methods have been widely used to extract and interpret the relevant information in data analysis. However when these methods are used alone on complex datasets, their effectivity is limited due to several factors. Most of the commonly used computational tools often lead to hard to interpret results that may not be reliable most of the time. This thesis aims to enhance data analysis procedures by integrating computational tools with interactive visual methodologies. The contributions of this thesis are mainly focused on the analysis of (very) high-dimensional data, i.e., hundreds and even thousands of dimensions, and cluster analysis. We introduce the dual analysis approach that makes it possible to analyze the items and the dimensions of a dataset in parallel in two linked visualization spaces. This methodology provides a basis to visually characterize and investigate dimensions as first-order analysis objects. We describe structure-aware analysis procedures that are facilitated by representative factors. Moreover, we present several mechanisms to achieve outlier-aware analysis routines. We describe the notion of outlyingness for the dimensions of a dataset and discuss how they can be determined and treated properly. We then focus on enhancing the dialogue between the analyst and the computer when computational methods are used interactively. We describe how different human factors come into play in visual analysis applications and propose optimized analytical processes that try to comply with the human capabilities. All these different approaches are demonstrated with various use-cases performed mostly together with experts from medical, genetic, and molecular biology domain. ",
    pdf = "pdfs/turkay13thesis.pdf",
    images = "images/turkay13thesis.png",
    thumbnails = "images/turkay13thesis.png",
    isbn = "?? ",
    project = "medviz"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Parulek13Seamless,
    author = "Julius Parulek and Timo Ropinski and Ivan Viola",
    title = "Seamless Abstraction of Molecular Surfaces",
    booktitle = "Proceedings of the 29th Spring Conference on Computer Graphics",
    year = "2013",
    series = "SCCG '13",
    pages = "120--127",
    abstract = "Molecular visualization is often challenged with rendering of large sequences of molecular simulations in real time. We introduce a novel approach that enables us to show even large protein complexes over time in real-time. Our method is based on the level-ofdetail concept, where we exploit three different molecular surface models, solvent excluded surface (SES), Gaussian kernels and van der Waals spheres combined in one visualization. We introduce three shading levels that correspond to their geometric counterparts and a method for creating seamless transition between these representations. The SES representation with full shading and added contours stands in focus while on the other side a sphere representation with constant shading and without contours provide the context. Moreover, we introduce a methodology to render the entire molecule directly using the A-buffer technique, which further improves the performance. The rendering performance is evaluated on series of molecules of varying atom counts. ",
    pdf = "pdfs/Parulek13Seamless.pdf",
    images = "images/Parulek13Seamless01.png, images/Parulek13Seamless02.png",
    thumbnails = "images/Parulek13Seamless01_thumb.png, images/Parulek13Seamless02.png",
    proceedings = "Proceedings of the 29th Spring Conference on Computer Graphics",
    isbn = "978-80-223-3377-1",
    location = "Smolenice, Slovak Republic",
    numpages = "8",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @MISC {Hauser2013SouthCHI,
    author = "Helwig Hauser",
    title = "Integrating Interactive and Computational Analysis in Visualization",
    howpublished = "Keynote talk at SouthCHI 2013 in Maribor, Slovenia.",
    month = "June",
    year = "2013",
    abstract = "Keynote talk at SouthCHI 2013 in Maribor, Slovenia.",
    pdf = "pdfs/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up.pdf",
    images = "images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(6).jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(5).jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(4).jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(3).jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(2).jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001.jpg, images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0003.jpg",
    thumbnails = "images/2013-07-02--Maribor--SouthCHI--Keynote--IVA--print2up_Image_0001(6).jpg"
    }
    [DOI] [Bibtex]
    @INCOLLECTION {Turkay13Hypothesis,
    author = "Cagatay Turkay and Arvid Lundervold and Astri Johansen Lundervold and Helwig Hauser",
    title = "Hypothesis Generation by Interactive Visual Exploration of Heterogeneous Medical Data",
    booktitle = "Human-Computer Interaction and Knowledge Discovery in Complex, Unstructured, Big Data",
    publisher = "Springer Berlin Heidelberg",
    year = "2013",
    editor = "Holzinger, Andreas and Pasi, Gabriella",
    volume = "7947",
    series = "Lecture Notes in Computer Science",
    pages = "1--12",
    images = "images/Turkay13Hypothesis_01.png",
    thumbnails = "images/Turkay13Hypothesis_01.png",
    isbn = "978-3-642-39145-3",
    doi = "10.1007/978-3-642-39146-0_1",
    url = "http://dx.doi.org/10.1007/978-3-642-39146-0_1",
    keywords = "interactive visual analysis; high dimensional medical data",
    pres = "pdfs/Turkay13Hypothesis.pdf"
    }
    [Bibtex]
    @MISC {Kingman13ScienceFilm,
    author = "Pina Kingman",
    title = "Animating Biology: The making of a science film",
    howpublished = "Presentation in the VisBio 2013",
    month = "September",
    year = "2013",
    abstract = "Biology is complicated. Understanding cellular and molecular biology is particularly difficult. Amongst the many effective communication tools at our disposal, animated film is at the forefront. Animation brings biological stories to life, and thus aids in our understanding of biological structure and function. Whether used to inform patients, to teach undergraduate biology, or to disseminate advances in research, animated film is a tool worth employing. But what goes into an animation? I will explain the step-by-step process of creating animations and show a lot of inspiring examples.",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Bergen, Norway",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @PHDTHESIS {lidal13thesis,
    author = "Endre M. Lidal",
    title = "Sketch-based Storytelling for Cognitive Problem Solving",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2013",
    month = "June",
    abstract = "Problem solving is an important part of all engineering and scienti�c activities. It is present, for instance, when experts want to develop more fuel- ef�cient cars or when they are searching for oil and gas in the subsurface. Many alternatives have to be examined and evaluated before the optimal solution is found. Solving such problems is not only performed inside the mind of the scientist, but it is also an interaction between mind and scribbles, sketches, or visualizations on papers, on blackboards, and on computers. For problem solving in expert teams, this externalization through sketches and visualizations also plays an important communicative role. This dissertation presents research for assisting the problem- solving process on the computer, through novel technological advances in the �elds of illustrative visualization and sketch-based modeling. Speci�cally, it targets problems that are related to evolutionary processes. Firstly, inspired by storytelling, the domain experts can express their ideas for solution as stories. These stories are based on sketches that the experts draw, utilizing a novel temporal-sketching interface inspired by a flip-over canvas metaphor. Further, the dissertation describes a set of sketching proxy geometries, such as the box-proxy geometry, that the experts can take advantage of when drawing three-dimensional (3D) sketches. These proxy geometries support the task of mapping a two-dimensional input (2D), e.g., a mouse or a digitizer tablet, to a 3D sketch. Solving dif�cult problems require that many different solutions are evaluated to identify the most optimal one. This dissertation introduces the story-tree, a tree-graph data structure and visualization, which manages and provides access to an ensemble of alternative stories. The story- tree also provides an interface where the stories can be evaluated and compared. This playback of the stories is done through automatic animations of the 2D sketches. The third challenge addressed in this dissertation is to communicate the optimal solution to decision-makers and laymen. By combining the animated 2D story sketches with illustrative visualization techniques it is possible to automatically synthesize and animate 3D models. These animations can be combined with new cutaway visualization techniques to reveal features hidden inside such 3D models. All of these contributions have been investigated in the context of the problemsolving tasks relevant to the early phase of petroleum exploration. This phase is characterized by having very little ground-through data available. Thus, a large solution space needs to be explored. Even so, the geologists need to produce models that can predict if petroleum is present. In addition to working with few data, the geologists also work under heavy time constraints because of the competition between the oil companies exploring the same area. The contributions from this dissertation have created enthusiasm among the domain experts and already, a new research initiative has materialized from the work described in this dissertation. Based on the feedback from the domain experts, we can conclude that the contributions presented in this dissertation form a valuable step towards better tools for problem solving, involving the computer, for the domain investigated here. ",
    pdf = "pdfs/lidal13thesis.pdf",
    images = "images/lidal13thesis.png",
    thumbnails = "images/lidal13thesis.png",
    isbn = "978-82-308-2330-9",
    project = "geoillustrator"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Brambilla13Integrated,
    author = "Andrea Brambilla and {\O }yvind Andreassen and Helwig Hauser",
    title = "Integrated Multi-aspect visualization of 3D Fluid Flows",
    booktitle = "Proc. of VMV 2013: Vision, Modeling \& Visualization",
    year = "2013",
    pages = "1--9",
    month = "Sept.",
    abstract = "The motion of a fluid is affected by several intertwined flow aspects. Analyzing one aspect at a time can only yield partial information about the flow behavior. More details can be revealed by studying their interactions. Our approach enables the investigation of these interactions by simultaneously visualizing meaningful flow aspects, such as swirling motion and shear strain. We adopt the notions of relevance and coherency. Relevance identifies locations where a certain flow aspect is deemed particularly important. The related piece of information is visualized by a specific visual entity, placed at the corresponding location. Coherency instead represents the homogeneity of a flow property in a local neighborhood. It is exploited in order to avoid visual redundancy and to reduce occlusion and cluttering. We have applied our approach to three CFD datasets, obtaining meaningful insights.",
    pdf = "pdfs/Brambilla13Integrated.pdf",
    images = "images/Brambilla13Integrated_00.png, images/Brambilla13Integrated_01.png",
    thumbnails = "images/Brambilla13Integrated_thumb00.png, images/Brambilla13Integrated_thumb01.png",
    proceedings = "Proc. of VMV 2013: Vision, Modeling \& Visualization",
    url = "http://diglib.eg.org/EG/DL/PE/VMV/VMV13/001-009.pdf",
    doi = "10.2312/PE.VMV.VMV13.001-009",
    location = "Lugano, Switzerland",
    pres = "pdfs/Brambilla13Integrated.pptx",
    extra = "extra/Brambilla13Integrated_extra.pdf"
    }
    [DOI] [Bibtex]
    @ARTICLE {Sima13Computer,
    author = "Aleksandra Sima and Xavier Bonaventura and Miquel Feixas and Mateu Sbert and John Howell and Ivan Viola and Simon Buckley",
    title = "Computer-aided image geometry analysis and subset selection for optimizing texture quality in photorealistic models",
    journal = "Computers and Geosciences",
    year = "2013",
    volume = "52",
    pages = "281-291",
    abstract = "Photorealistic 3D models are used for visualization, interpretation and spatial measurement in many disciplines, such as cultural heritage, archaeology and geoscience. Using modern image- and laser-based 3D modelling techniques, it is normal to acquire more data than is finally used for 3D model texturing, as images may be acquired from multiple positions, with large overlap, or with different cameras and lenses. Such redundant image sets require sorting to restrict the number of images, increasing the processing efficiency and realism of models. However, selection of image subsets optimized for texturing purposes is an example of complex spatial analysis. Manual selection may be challenging and time-consuming, especially for models of rugose topography, where the user must account for occlusions and ensure coverage of all relevant model triangles. To address this, this paper presents a framework for computer- aided image geometry analysis and subset selection for optimizing texture quality in photorealistic models. The framework was created to offer algorithms for candidate image subset selection, whilst supporting refinement of subsets in an intuitive and visual manner. Automatic image sorting was implemented using algorithms originating in computer science and information theory, and variants of these were compared using multiple 3D models and covering image sets, collected for geological applications. The image subsets provided by the automatic procedures were compared to manually selected sets and their suitability for 3D model texturing was assessed. Results indicate that the automatic sorting algorithms are a promising alternative to manual methods. An algorithm based on a greedy solution to the weighted set-cover problem provided image sets closest to the quality and size of the manually selected sets. The improved automation and more reliable quality indicators make the photorealistic model creation workflow more accessible for application experts, increasing the user’s confidence in the final textured model completeness.",
    images = "images/Sima13Computer01.png, images/Sima13Computer02.png",
    thumbnails = "images/Sima13Computer01_thumb.png, images/Sima13Computer02_thumb.png",
    doi = "10.1016/j.cageo.2012.11.004",
    url = "http://www.sciencedirect.com/science/article/pii/S0098300412003743"
    }
    [Bibtex]
    @MISC {Parulek13Analysis,
    author = "Julius Parulek",
    title = "Interactive Visual Exploration and Analysis of High-Dimensional, Temporal, and Heterogeneous Biological Data",
    howpublished = "Presentation in the VisBio 2013",
    month = "September",
    year = "2013",
    abstract = "High-dimensional data (hundreds of dimensions, or more) and temporal data (thousands of time frames) pose substantial challenges for both computational and interactive analysis. To reveal relevant intrinsic relations between items or dimensions, the utilization of only computational methods or standard visualization techniques is not enough. In this talk, we introduce the concept of interactive visual analysis (IVA) that enables us to combine computational methods with the user knowledge through a system of multiple linked views on the data and advanced interaction mechanisms. Our approach allows us to interact with the data on the level of individual items and also on the level of dimensions, exploiting a number of useful statistical methods in addition. To improve the understanding of temporal data, we utilize clustering methods, where the user is provided means to understand the internal cluster structure. Moreover, we also showcase how IVA can be beneficial when analyzing molecular dynamics.",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Bergen, Norway",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @ARTICLE {Alsallakh13Radial,
    author = "B. Alsallakh and W. Aigner and S. Miksch and H. Hauser",
    title = "Radial Sets: Interactive Visual Analysis of Large Overlapping Sets",
    journal = "IEEE Transactions on Visualization and Computer Graphics",
    year = "2013",
    volume = "19",
    number = "12",
    pages = "2496-2505",
    abstract = "In many applications, data tables contain multi-valued attributes that often store the memberships of the table entities to multiple sets such as which languages a person masters, which skills an applicant documents, or which features a product comes with. With a growing number of entities, the resulting element-set membership matrix becomes very rich of information about how these sets overlap. Many analysis tasks targeted at set-typed data are concerned with these overlaps as salient features of such data. This paper presents Radial Sets, a novel visual technique to analyze set memberships for a large number of elements. Our technique uses frequency-based representations to enable quickly finding and analyzing different kinds of overlaps between the sets, and relating these overlaps to other attributes of the table entities. Furthermore, it enables various interactions to select elements of interest, find out if they are over-represented in specific sets or overlaps, and if they exhibit a different distribution for a specific attribute compared to the rest of the elements. These interactions allow formulating highly-expressive visual queries on the elements in terms of their set memberships and attribute values. As we demonstrate via two usage scenarios, Radial Sets enable revealing and analyzing a multitude of overlapping patterns between large sets, beyond the limits of state-of-the-art techniques.",
    images = "images/Alsallakh13Radial_3.jpg, images/Alsallakh13Radial_1.jpg, images/Alsallakh13Radial_2.jpg",
    thumbnails = "images/Alsallakh13Radial_3_thumb.png, images/Alsallakh13Radial_1_thumb.png, images/Alsallakh13Radial_2_thumb.png",
    url = "http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6634104",
    doi = "10.1109/TVCG.2013.184",
    issn = "1077-2626"
    }
    [DOI] [Bibtex]
    @ARTICLE {Lovset13Rule,
    author = "Tyge L{\o }vset and Dag Magne Ulvang and Tor Christian Bekkvik and K{\aa}re Villanger and Ivan Viola",
    title = "Rule-based method for automatic scaffold assembly from 3D building models",
    journal = "Computers \& Graphics",
    year = "2013",
    volume = "37",
    number = "4",
    pages = "256--268",
    abstract = "To manually specify an optimal scaffold assembly for a given building geometry is a time consuming task. Our goal is to automate the process of selecting and placing scaffold components in order to design an optimal scaffold assembly for a specific building. The resulting assembly must be possible to construct in practice, should be practical to use for the workers, must satisfy governmental rules and regulations and should ideally result in minimum accumulated component cost. We propose a novel procedural modeling pipeline based on an input house model. First we extract vital coordinates from the house model that define the 3D scaffold placement. These coordinates are the basis for defining the positioning of scaffold cells. In the next step we populate the cells with actual scaffold components geometry. The resulting model is visualized to assist the assembly process. Additionally it is decomposed into elementary building blocks to produce assembly component lists to estimate the scaffold cost estimates, compute the weight for transportation and packing of components from a warehouse. The result from the automated process is compared to scaffold design produced manually by a professional scaffold designer.",
    images = "images/Lovset13Rule01.png, images/Lovset13Rule02.png",
    thumbnails = "images/Lovset13Rule01_thumb.png, images/Lovset13Rule02_thumb.png",
    issn = "0097-8493",
    doi = "10.1016/j.cag.2013.01.007",
    url = "http://www.sciencedirect.com/science/article/pii/S0097849313000095"
    }
    [PDF] [Bibtex]
    @MISC {Parulek13Importance,
    author = "Julius Parulek and Timo Ropinski and Ivan Viola",
    title = "Importance Driven Visualization of Molecular Surfaces",
    howpublished = "Poster presented at the BioVis conference 2013",
    month = "October",
    year = "2013",
    pdf = "pdfs/Parulek13Importance.pdf",
    images = "images/Parulek13Importance.png",
    thumbnails = "images/Parulek13Importance.png",
    location = "Atlanta (GA)",
    project = "physioillustration"
    }
    [Bibtex]
    @MISC {Hauser13VisTutorial,
    author = "Steffen Oeltze and Johannes Kehrer and Helwig Hauser",
    title = "Interactive Visual Analysis of Scientific Data",
    howpublished = "Tutorial at the IEEE VisWeek 2013",
    month = "October",
    year = "2013",
    abstract = "In a growing number of application areas, a subject or phenomenon is investigated by means of multiple datasets being acquired over time (spatiotemporal), comprising several attributes per data point (multi-variate), stemming from different data sources (multi-modal) or multiple simulation runs (multi-run/ensemble) [KH13]. Interactive visual analysis (IVA) comprises concepts and techniques for a user-guided knowledge discovery in such complex data. Through a tight feedback loop of computation, visualization and user interaction, it provides new insight into the data and serves as a vehicle for hypotheses generation or validation. It is often implemented via a multiple coordinated view framework where each view is equipped with interactive drill-down operations for focusing on data features. Two classes of views are integrated: physical views, such as direct volume rendering, show information in the context of the spatiotemporal observation space while attribute views, such as scatter plots and parallel coordinates, show relationships between multiple data attributes. The user may drill-down the data by selecting interesting regions of the observation space or attribute ranges leading to a consistent highlighting of this selection in all other views (brushing-and-linking). Three patterns of explorative/analytical procedures may be accomplished by doing so. In a feature localization, the user searches for places in the 3D/4D observation space where certain attribute values are present. In a multi-variate analysis, relations between data attributes are investigated, e.g., by searching for correlations. In a local investigation, the user inspects the values of selected attributes with respect to certain spatiotemporal subsets of the observation space. In this tutorial, we discuss examples for successful applications of IVA to scientific data from various fields: climate research, medicine, epidemiology, and flow simulation / computation, in particular for automotive engineering. We base our discussions on a theoretical foundation of IVA which helps the tutorial attendees in transferring the subject matter to their own data and application area. In the course of the tutorial, the attendees will become acquainted with techniques from statistics and knowledge discovery, which proved to be particularly useful for a specific IVA application. The tutorial further comprises an overview of off-the-shelf IVA solutions, which may be be particularly interesting for visualization practitioners. It is concluded by a summary of the gained knowledge and a discussion of open problems in IVA of scientific data.",
    images = "images/",
    thumbnails = "images/iva_scientificdata_proposal_2013_Image.png",
    location = "Atlanta (GA), USA",
    pres = "pdfs/iva_scientificdata_proposal_2013.pdf"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Natali13Modeling,
    author = "Mattia Natali and Endre M. Lidal and Julius Parulek and Ivan Viola and Daniel Patel",
    title = "Modeling Terrains and Subsurface Geology",
    booktitle = "EuroGraphics 2013 State of the Art Reports (STARs)",
    year = "2013",
    pages = "155--173",
    abstract = "The process of creating terrain and landscape models is important in a variety of computer graphics and visualization applications, from films and computer games, via flight simulators and landscape planning, to scientific visualization and subsurface modelling. Interestingly, the modelling techniques used in this large range of application areas have started to meet in the last years. In this state-of-the-art report, we present two taxonomies of different modelling methods. Firstly we present a data oriented taxonomy, where we divide modelling into three different scenarios: the data-free, the sparse-data and the dense-data scenario. Then we present a workflow oriented taxonomy, where we divide modelling into the separate stages necessary for creating a geological model. We start the report by showing that the new trends in geological modelling are approaching the modelling methods that have been developed in computer graphics. We then give an introduction to the process of geological modelling followed by our two taxonomies with descriptions and comparisons of selected methods. Finally we discuss the challenges and trends in geological modelling.",
    pdf = "pdfs/Natali13Modeling.pdf",
    images = "images/Natali13Modeling.png",
    thumbnails = "images/Natali13Modeling.png",
    proceedings = "EuroGraphics 2013 State of the Art Reports (STARs)",
    url = "http://diglib.eg.org/EG/DL/conf/EG2013/stars/155-173.pdf",
    doi = "10.2312/conf/EG2013/stars/155-173",
    location = "Girona, Spain",
    project = "geoillustrator"
    }
    [DOI] [Bibtex]
    @ARTICLE {Parulek13Visual,
    author = "Julius Parulek and Cagatay Turkay and Nathalie Reuter and Ivan Viola",
    title = "Visual cavity analysis in molecular simulations",
    journal = "BMC Bioinformatics",
    year = "2013",
    volume = "14",
    number = "Suppl 19",
    pages = "S4",
    month = "Nov.",
    abstract = "Molecular surfaces provide a useful mean for analyzing interactions between biomolecules; such as identification and characterization of ligand binding sites to a host macromolecule. We present a novel technique, which extracts potential binding sites, represented by cavities, and characterize them by 3D graphs and by amino acids. The binding sites are extracted using an implicit function sampling and graph algorithms. We propose an advanced cavity exploration technique based on the graph parameters and associated amino acids. Additionally, we interactively visualize the graphs in the context of the molecular surface. We apply our method to the analysis of MD simulations of Proteinase 3, where we verify the previously described cavities and suggest a new potential cavity to be studied.",
    images = "images/Parulek13Visual01.png, images/Parulek13Visual02.png",
    thumbnails = "images/Parulek13Visual01_thumb.png, images/Parulek13Visual02_thumb.png",
    url = "http://www.biomedcentral.com/1471-2105/14/S19/S4",
    doi = "10.1186/1471-2105-14-S19-S4",
    issn = "1471-2105",
    project = "physioillustration"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Lidal13Rapid,
    author = "Endre Lidal and Daniel Patel and Morten Bendiksen and Tor Langeland and Ivan Viola",
    title = "Rapid Sketch-based 3D Modeling of Geology",
    booktitle = "Proceedings of EnvirVis Short Papers 2013",
    year = "2013",
    abstract = "We present and compare two different approaches for performing rapid 3D geological modeling. The ad-hoc approach is based on a composition of many specialized modeling functions, while the generic approach provides one powerful, generic modeling function. Our experiences after developing these two approaches are that the solution space of 3D geological modeling is more extensive than we initially expected and most likely larger than for other modeling domains such as architecture. Further, more research is needed to investigate whether it is possible to �nd one well de�ned toolset of sketching metaphors that is able to cover all of geological modeling.",
    pdf = "pdfs/Lidal13Rapid.pdf",
    images = "images/Lidal13Rapid01.png",
    thumbnails = "images/Lidal13Rapid01_thumb.png",
    project = "geoillustrator"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Birkeland13Doppler,
    author = "{\AA}smund Birkeland and Dag Magne Ulvang and Kim Nylund and Trygve Hausken and Odd Helge Gilja and Ivan Viola",
    title = "Doppler-based 3D Blood Flow Imaging and Visualization",
    booktitle = "Proceedings of the 29th Spring Conference on Computer Graphics",
    year = "2013",
    abstract = "Blood flow is a very important part of human physiology. In this paper, we present a new method for estimating and visualizing 3D blood flow on-the-fly based on Doppler ultrasound. We add semantic information about the geometry of the blood vessels in order to recreate the actual velocities of the blood. Assuming a laminar flow, the flow direction is related to the general direction of the vessel. Based on the center line of the vessel, we create a vector field representing the direction of the vessel at any given point. The actual flow velocity is then estimated from the Doppler ultrasound signal by back-projecting the velocity in the measured direction, onto the vessel direction. Additionally, we estimate the flux at user-selected cross-sections of the vessel by integrating the velocities over the area of the cross- section. In order to visualize the flow and the flux, we propose a visualization design based on traced particles colored by the flux. The velocities are visualized by animating particles in the flow field. Further, we propose a novel particle velocity legend as a means for the user to estimate the numerical value of the current velocity. Finally, we perform an evaluation of the technique where the accuracy of the velocity estimation is measured using a 4D MRI dataset as a basis for the ground truth.",
    pdf = "pdfs/Birkeland13Doppler.pdf",
    images = "images/Birkeland13Doppler01.png, images/Birkeland13Doppler02.png",
    thumbnails = "images/Birkeland13Doppler01_thumb.png, images/Birkeland13Doppler02_thumb.png",
    project = "illustrasound,medviz,illvis"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Borgo13GlyphBased,
    author = "Rita Borgo and Johannes Kehrer and David H. S. Chung and Eamonn Maguire and Robert S. Laramee and Helwig Hauser and Matthew Ward and Min Chen ",
    title = "Glyph-based Visualization: Foundations, Design Guidelines, Techniques and Applications",
    booktitle = "EuroGraphics 2013 State-of-the-Art Reports (STARs)",
    year = "2013",
    pages = "39--63",
    address = "Girona, Spain",
    publisher = "Eurographics Association",
    abstract = "This state of the art report focuses on glyph-based visualization, a common form of visual design where a data set is depicted by a collection of visual objects referred to as glyphs. Its major strength is that patterns of multivariate data involving more than two attribute dimensions can often be more readily perceived in the context of a spatial relationship, whereas many techniques for spatial data such as direct volume rendering find difficult to depict with multivariate or multi-field data, and many techniques for non-spatial data such as parallel coordinates are less able to convey spatial relationships encoded in the data. This report fills several major gaps in the literature, drawing the link between the fundamental concepts in semiotics and the broad spectrum of glyph-based visualization, reviewing existing design guidelines and implementation techniques, and surveying the use of glyph-based visualization in many applications.",
    pdf = "pdfs/Borgo13GlyphBased.pdf",
    images = "images/Borgo13GlyphBased.jpg",
    thumbnails = "images/Borgo13GlyphBased.jpg",
    url = "http://diglib.eg.org/EG/DL/conf/EG2013/stars/039-063.pdf",
    issn = "1017-4656",
    doi = "10.2312/conf/EG2013/stars/039-063"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Matkovic13Interactive,
    author = "Kresimir Matkovic and Mario Duras and Denis Gracanin and Rainer Splechtna and Benedikt Stehno and Helwig Hauser ",
    title = "Interactive Visual Analysis in the Concept Stage of a Hybrid-Vehicle Design",
    booktitle = "EuroVis Workshop on Visual Analytics",
    year = "2013",
    pages = "61--65",
    address = "Leipzig, Germany",
    publisher = "Eurographics Association",
    abstract = "The design of modern, hybrid vehicles is an active area of research. As the whole field is new, engineers need intuitive and powerful support tools. In this application paper, we illustrate an application of interactive visual analysis in the concept phase of a hybrid-vehicle design. We exploit coordinated multiple views to explore and analyze a simulation ensemble - a set of simulation runs of the same simulation model. Once we reduce the ensemble to a single run we use a detailed view, including an energy flow graph and a vehicle drive animation. Very positive feedback from domain experts and opportunities for additional improvements encourage further research.",
    pdf = "pdfs/Matkovic13Interactive.pdf",
    images = "images/Matkovic13Interactive_0.jpg, images/Matkovic13Interactive_1.jpg, images/Matkovic13Interactive_2.jpg, images/Matkovic13Interactive_3.jpg",
    thumbnails = "images/Matkovic13Interactive_0_thumb.jpg, images/Matkovic13Interactive_1.jpg, images/Matkovic13Interactive_2.jpg, images/Matkovic13Interactive_3.jpg",
    url = "http://diglib.eg.org/EG/DL/PE/EuroVAST/EuroVA13/061-065.pdf",
    doi = "10.2312/PE.EuroVAST.EuroVA13.061-065",
    isbn = "978-3-905674-55-2"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {Glasser13VisualAnalysis,
    author = "Sylvia Glasser and Steffen Oeltze and Uta Preim and Atle Bj{\O }rnerud and Helwig Hauser and Bernhard Preim",
    title = "Visual analysis of longitudinal brain tumor perfusion",
    booktitle = "Proc. SPIE",
    year = "2013",
    volume = "8670",
    pages = "86700Z-86700Z-11",
    abstract = "In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.",
    images = "images/Glasser13VisualAnalysis_0.jpg, images/Glasser13VisualAnalysis_1.jpg",
    thumbnails = "images/Glasser13VisualAnalysis_0.jpg, images/Glasser13VisualAnalysis_1.jpg",
    doi = "10.1117/12.2007878",
    url = "http://dx.doi.org/10.1117/12.2007878",
    project = "yggdrasil, medviz"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {Viola2013Dirk,
    author = "Ivan Viola and {\AA},smund Birkeland and Veronika \v{S},olt{\'e},szov{\'a}, and Linn Helljesen and Helwig Hauser and Spiros Kotopoulis and Kim Nylund and Dag M. Ulvang and Ola K. {\O }ye and Trygve Hausken and Odd H. Gilja",
    title = "High-Quality 3{D} Visualization of In-Situ Ultrasonography",
    booktitle = "EG 2013---Dirk Bartz Prize",
    year = "2013",
    pages = "1-4",
    abstract = "In recent years medical ultrasound has experienced a rapid development in the quality of real-time 3D ultrasound (US) imaging. The image quality of the 3D volume that was previously possible to achieve within the range of a few seconds, is now possible in a fraction of a second. This technological advance offers entirely new opportunities for the use of US in the clinic. In our project, we investigate how real-time 3D US can be combined with high-performance processing of today's graphics hardware to allow for high-quality 3D visualization and precise navigation during the examination. ",
    images = "images/2013-05-08--DirkBartzPrizeComb.jpg",
    thumbnails = "images/2013-05-08--DirkBartzPrizeComb.jpg",
    doi = "10.2312/conf/EG2013/med/001-004",
    url = "http://diglib.eg.org/EG/DL/conf/EG2013/med/001-004.pdf.abstract.pdf;internal\&action=action.digitallibrary.ShowPaperAbstract",
    project = "illustrasound,medviz,illvis"
    }
    [PDF] [Bibtex]
    @MISC {Smestad13Advanced,
    author = "Geir Smestad and Paolo Angelelli and Helwig Hauser",
    title = "Advanced data fusion in 4-D color doppler volume visualization",
    howpublished = "Poster presented at the MedIm conference 2013",
    month = "October",
    year = "2013",
    pdf = "pdfs/Smestad13Advanced.pdf",
    images = "images/Smestad13Advanced.jpg",
    thumbnails = "images/Smestad13Advanced_thumb.jpg",
    location = "Troms{\O }",
    project = "bia"
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Auzinger-2013-VVC,
    author = {Thomas Auzinger and Gabriel Mistelbauer and Ivan Baclija and R{\"u}diger Schernthaner and Arnold K{\"o}chl and Michael Wimmer and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {Vessel Visualization using Curved Surface Reformation},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2013},
    volume = {19},
    number = {12},
    pages = {2858--2867},
    month = {dec},
    abstract = {Visualizations of vascular structures are frequently used in radiological  investigations to detect and analyze vascular diseases. Obstructions  of the blood flow through a vessel are one of the main interests  of physicians, and several methods have been proposed to aid the  visual assessment of calcifications on vessel walls. Curved Planar  Reformation (CPR) is a wide-spread method that is designed for peripheral  arteries which exhibit one dominant direction. To analyze the lumen  of arbitrarily oriented vessels, Centerline Reformation (CR) has  been proposed. Both methods project the vascular structures into  2D image space in order to reconstruct the vessel lumen. In this  paper, we propose Curved Surface Reformation (CSR), a technique that  computes the vessel lumen fully in 3D. This offers high-quality interactive  visualizations of vessel lumina and does not suffer from problems  of earlier methods such as ambiguous visibility cues or premature  discretization of centerline data. Our method maintains exact visibility  information until the final query of the 3D lumina data. We also  present feedback from several domain experts.},
    doi = {10.1109/TVCG.2013.215},
    event = {IEEE VIS 2013},
    images = {images/Auzinger-2013-VVC.jpg},
    keywords = {volume Rendering, reformation, vessel, surface approximation},
    pdf = {pdfs/Auzinger-2013-VVC.pdf},
    thumbnails = {images/Auzinger-2013-VVC.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/Auzinger_Mistelbauer_2013_CSR/},
    youtube = {https://www.youtube.com/watch?v=rESIFaO_-Gs},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Karimov-2013-VSV,
    author = {Alexey Karimov and Gabriel Mistelbauer and Johanna Schmidt and Peter Mindek and Elisabeth Schmidt and Timur Sharipov and Stefan Bruckner and Meister Eduard Gr{\"o}ller},
    title = {ViviSection: Skeleton-based Volume Editing},
    journal = {Computer Graphics Forum},
    year = {2013},
    volume = {32},
    number = {3},
    pages = {461--470},
    month = jun,
    abstract = {Volume segmentation is important in many applications, particularly
    in the medical domain. Most segmentation techniques, however, work
    fully automatically only in very restricted scenarios and cumbersome
    manual editing of the results is a common task. In this paper, we
    introduce a novel approach for the editing of segmentation results.
    Our method exploits structural features of the segmented object to
    enable intuitive and robust correction and verification. We demonstrate
    that our new approach can significantly increase the segmentation
    quality even in difficult cases such as in the presence of severe
    pathologies.},
    doi = {10.1111/cgf.12133},
    event = {EuroVis 2013},
    images = {images/Karimov-2013-VSV.jpg},
    keywords = {volume visualization, volume editing, segmentation, interaction},
    location = {Leipzig, Germany},
    pdf = {pdfs/Karimov-2013-VSV.pdf},
    thumbnails = {images/Karimov-2013-VSV.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/karimov-2013-vivisection/},
    youtube = {https://www.youtube.com/watch?v=4s12ZbUyHiY},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @InProceedings{Mindek-2013-CSE,
    author = {Peter Mindek and Stefan Bruckner and Meister Eduard Gr{\"o}ller},
    title = {Contextual Snapshots: Enriched Visualization with Interactive Spatial Annotations},
    booktitle = {Proceedings of SCCG 2013},
    year = {2013},
    pages = {59--66},
    month = may,
    note = {SCCG 2013 Best Paper Award},
    abstract = {Spatial selections are a ubiquitous concept in visualization. By localizing
    particular features, they can be analyzed and compared in different
    views. However, the semantics of such selections are often dependent
    on other parameter settings and it can be difficult to reconstruct
    them without additional information. In this paper, we present the
    concept of contextual snapshots as an effective means for managing
    spatial selections in visualized data. The selections are automatically
    associated with the context in which they have been created. Contextual
    snapshots can be also used as the basis for interactive integrated
    and linked views, which enable in-place investigation and comparison
    of multiple visual representations of data. Our approach is implemented
    as a flexible toolkit with welldefined interfaces for integration
    into existing systems. We demonstrate the power and generality of
    our techniques by applying them to several distinct scenarios such
    as the visualization of simulation data and the analysis of historical
    documents.},
    doi = {10.1145/2508244.2508251},
    images = {images/Mindek-2013-CSE.jpg},
    keywords = {spatial selections, annotations, linked views, provenance},
    location = {Smolenice, Slovakia},
    pdf = {pdfs/Mindek-2013-CSE.pdf},
    thumbnails = {images/Mindek-2013-CSE.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/mindek-2013-csl/},
    youtube = {https://www.youtube.com/watch?v=djuqJgixUCs},
    }
    [PDF] [YT] [Bibtex]
    @Article{Mindek-2013-VPE,
    author = {Peter Mindek and Stefan Bruckner and Peter Rautek and Meister Eduard Gr{\"o}ller},
    title = {Visual Parameter Exploration in {GPU} Shader Space},
    journal = {Journal of WSCG},
    year = {2013},
    volume = {21},
    number = {3},
    pages = {225--234},
    month = jun,
    abstract = {The wide availability of high-performance GPUs has made the use of
    shader programs in visualization ubiquitous.Understanding shaders
    is a challenging task. Frequently it is difficult to mentally reconstruct
    the nature and types of transformations applied to the underlying
    data during the visualization process. We propose a method for the
    visual analysis of GPU shaders, which allows the flexible exploration
    and investigation of algorithms, parameters, and their effects. We
    introduce a method for extracting feature vectors composed of several
    attributes of the shader, as well as a direct manipulation interface
    for assigning semantics to them. The user interactively classifies
    pixels of images which are rendered with the investigated shader.
    The two resulting classes, a positive class and a negative one, are
    employed to steer the visualization. Based on this information, we
    can extract a wide variety of additional attributes and visualize
    their relation to this classification. Our system allows an interactive
    exploration of shader space and we demonstrate its utility for several
    different applications.},
    images = {images/Mindek-2013-VPE.jpg},
    keywords = {parameter space exploration, shader augmentation},
    pdf = {pdfs/Mindek-2013-VPE.pdf},
    thumbnails = {images/Mindek-2013-VPE.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/mindek-2013-pel/},
    youtube = {https://www.youtube.com/watch?v=Sk7EXvqCoxs},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Mistelbauer-2013-VVC,
    author = {Gabriel Mistelbauer and Anca Morar and Andrej Varchola and R{\"u}diger Schernthaner and Ivan Baclija and Arnold K{\"o}chl and Armin Kanitsar and Stefan Bruckner and Meister Eduard Gr{\"o}ller},
    title = {Vessel Visualization using Curvicircular Feature Aggregation},
    journal = {Computer Graphics Forum},
    year = {2013},
    volume = {32},
    number = {3},
    pages = {231--240},
    month = jun,
    abstract = {Radiological investigations are common medical practice for the diagnosis
    of peripheral vascular diseases. Existing visualization methods such
    as Curved Planar Reformation (CPR) depict calcifications on vessel
    walls to determine if blood is still able to flow. While it is possible
    with conventional CPR methods to examine the whole vessel lumen by
    rotating around the centerline of a vessel, we propose Curvicircular
    Feature Aggregation (CFA), which aggregates these rotated images
    into a single view. By eliminating the need for rotation, vessels
    can be investigated by inspecting only one image. This method can
    be used as a guidance and visual analysis tool for treatment planning.
    We present applications of this technique in the medical domain and
    give feedback from radiologists.},
    doi = {10.1111/cgf.12110},
    event = {EuroVis 2013},
    images = {images/Mistelbauer-2013-VVC.jpg},
    keywords = {medical visualization, vessel visualization, vessel reformation},
    location = {Leipzig, Germany},
    pdf = {pdfs/Mistelbauer-2013-VVC.pdf},
    thumbnails = {images/Mistelbauer-2013-VVC.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/mistelbauer-2013-cfa/},
    youtube = {https://www.youtube.com/watch?v=WwF5GPOs1pA},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Patel-2013-ICS,
    author = {Daniel Patel and Veronika \v{S}olt{\'e}szov{\'a} and Jan Martin Nordbotten and Stefan Bruckner},
    title = {Instant Convolution Shadows for Volumetric Detail Mapping},
    journal = {ACM Transactions on Graphics},
    year = {2013},
    volume = {32},
    number = {5},
    pages = {154:1--154:18},
    month = sep,
    abstract = {In this article, we present a method for rendering dynamic scenes
    featuring translucent procedural volumetric detail with all-frequency
    soft shadows being cast from objects residing inside the view frustum.
    Our approach is based on an approximation of physically correct shadows
    from distant Gaussian area light sources positioned behind the view
    plane, using iterative convolution. We present a theoretical and
    empirical analysis of this model and propose an efficient class of
    convolution kernels which provide high quality at interactive frame
    rates. Our GPU-based implementation supports arbitrary volumetric
    detail maps, requires no precomputation, and therefore allows for
    real-time modi?cation of all rendering parameters.},
    doi = {10.1145/2492684},
    images = {images/Patel-2013-ICS.jpg},
    keywords = {shadows, volumetric effects, procedural texturing, filtering},
    pdf = {pdfs/Patel-2013-ICS.pdf},
    project = {geoillustrator},
    thumbnails = {images/Patel-2013-ICS.png},
    url = {http://dl.acm.org/citation.cfm?id=2492684},
    youtube = {https://www.youtube.com/watch?v=lhGWgew3HXY,https://www.youtube.com/watch?v=XrhYjgQxfb0},
    }
    [PDF] [DOI] [YT] [Bibtex]
    @Article{Schmidt-2013-VVA,
    author = {Johanna Schmidt and Meister Eduard Gr{\"o}ller and Stefan Bruckner},
    title = {VAICo: Visual Analysis for Image Comparison},
    journal = {IEEE Transactions on Visualization and Computer Graphics},
    year = {2013},
    volume = {19},
    number = {12},
    pages = {2090--2099},
    month = dec,
    abstract = {Scientists, engineers, and analysts are confronted with ever larger
    and more complex sets of data, whose analysis poses special challenges.
    In many situations it is necessary to compare two or more datasets.
    Hence there is a need for comparative visualization tools to help
    analyze differences or similarities among datasets. In this paper
    an approach for comparative visualization for sets of images is presented.
    Well-established techniques for comparing images frequently place
    them side-by-side. A major drawback of such approaches is that they
    do not scale well. Other image comparison methods encode differences
    in images by abstract parameters like color. In this case information
    about the underlying image data gets lost. This paper introduces
    a new method for visualizing differences and similarities in large
    sets of images which preserves contextual information, but also allows
    the detailed analysis of subtle variations. Our approach identifies
    local changes and applies cluster analysis techniques to embed them
    in a hierarchy. The results of this process are then presented in
    an interactive web application which allows users to rapidly explore
    the space of differences and drill-down on particular features. We
    demonstrate the flexibility of our approach by applying it to multiple
    distinct domains.},
    doi = {10.1109/TVCG.2013.213},
    event = {IEEE VIS 2013},
    images = {images/Schmidt-2013-VVA.jpg},
    keywords = {focus+context visualization, image set comparison, comparative visualization},
    pdf = {pdfs/Schmidt-2013-VVA.pdf},
    thumbnails = {images/Schmidt-2013-VVA.png},
    url = {http://www.cg.tuwien.ac.at/research/publications/2013/schmidt-2013-vaico/},
    youtube = {https://www.youtube.com/watch?v=wfBqKZLVszk},
    }

2012

    [Bibtex]
    @MISC {Hauser12PaVis,
    author = "Helwig Hauser and Stephen G. Kobourov and Huamin Qu",
    title = "Proceedings of the 2012 IEEE Pacific Visualization Symposium",
    howpublished = "Conference proceedings",
    month = "February-March",
    year = "2012",
    images = "images/Helwig12PaVis01.png",
    thumbnails = "images/Helwig12PaVis01.png",
    location = "Songdo, Korea",
    url = "http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=6178307"
    }
    [PDF] [Bibtex]
    @ARTICLE {Brambilla12AHierarchical,
    author = "Andrea Brambilla and Ivan Viola and Helwig Hauser",
    title = "A Hierarchical Splitting Scheme to Reveal Insight into Highly Self-Occluded Integral Surfaces",
    journal = "Journal of WSCG",
    year = "2012",
    volume = "20",
    number = "1",
    pages = "57--64",
    month = "July",
    abstract = "In flow visualization, integral surfaces are of particular interest for their ability to describe trajectories of massless particles. In areas of swirling motion, integral surfaces can become very complex and difficult to understand. Taking inspiration from traditional illustration techniques, such as cut-aways and exploded views, we propose a surface analysis tool based on surface splitting and focus+context visualization. Our surface splitting scheme is hierarchical and at every level of the hierarchy the best cut is chosen according to a surface complexity metric. In order to make the interpretation of the resulting pieces straightforward, cuts are always made along isocurves of specific flow attributes. Moreover, a degree of interest can be specified, so that the splitting procedure attempts to unveil the occluded interesting areas. Through practical examples, we show that our approach is able to overcome the lack of understanding originating from structural occlusion.",
    pdf = "pdfs/Brambilla12AHierarchical.pdf",
    images = "images/Brambilla12AHierarchical01.png, images/Brambilla12AHierarchical02.png, images/Brambilla12AHierarchical03.png",
    thumbnails = "images/Brambilla12AHierarchical01_thumb.png, images/Brambilla12AHierarchical02_thumb.png, images/Brambilla12AHierarchical03_thumb.png",
    issn = "1213-6972",
    publisher = "Union Agency",
    url = "http://wscg.zcu.cz/JWSCG/",
    event = "WSCG 2012 - 20th International Conference on Computer Graphics, Visualization and Computer Vision",
    location = "Pilsen, Czech Republic",
    pres = "pdfs/Brambilla12AHierarchical.pptx",
    project = "semseg"
    }
    [Bibtex]
    @MISC {Pobitzer12Exploiting,
    author = "Armin Pobitzer",
    title = "Exploiting the Turbulence Energy Cascade for Flow Visualization",
    howpublished = "Invited talk at the weekly seminar of Laboratoire de M\'{e}canique de Lille",
    month = "February",
    year = "2012",
    abstract = "Even though modern technology and tools, together with available computer power, theoretically enable us to visualise large vector fields directly, it often is neither interesting nor necessary to visualise every detail of them. Usually, interesting features of the investigated field can be visualized more efficiently using dedicated feature detectors, e.g. the $\lambda_2$ criterion [2] for vertical structures. In settings with highly complex flow patterns, such as fully developed turbulence, feature detectors may, however, mark almost the whole flow domain as a feature. In these cases visualisations based on these detectors become hard to interpret due to occlusion and visual cluttering. This problem is well known in visualisation, and has been addressed by previous work. Many of these methods have in common that they extract all features at first, and discard some of them afterwards. Criteria for this discarding are often of geometrical character, such as size (volume, length, area ...) or distance to next feature. While the visual output of such strategies satisfies the need to reduce occlusion and visual clutter, the interpretability of the results remains an open question. The immediate relation between the velocity field and the output of the feature detector is lost, since the simplication is made on the `image-level' only. In this talk we discuss how the internal structure of flow fields can be exploited, in particular the turbulence energy cascade. Based on proper orthogonal decomposition [3], we present a general simplification scheme for feature extraction that preserves the 1-to-1 relation between visual output of the method and the flow pattern it is extracted from. We apply the simplification scheme on both Eulerian and Lagrangian feature detectors and discuss the results. In particular the impact of the simplification scheme on the detection and visualization of Lagrangian Coherent Structures based on Finite-time Lyapunov exponents is addressed. The results presented in this talk are published in the article `Energy-scale Aware Feature Extraction for Flow Visualization [4]. [1] L. Hesselink, J. Helman, and P. Ning, Quantitative image processing in fluid mechanics, Experimental Thermal and Fluid Science, 5 (1992), pp. 605-616. Special Issue on Experimental Methods in Thermal and Fluid Science. [2] J. Jeong and F. Hussain, On the identification of a vortex, Journal of Fluid Mechanics, 285 (1995), pp. 69-84. [3] J. L. Lumley, The structure of inhomogeneous turbulent flows, in Atmospheric Turbulence and Radio Wave Propagation, Elsevier, 1967, pp. 166-178. [4] A. Pobitzer, M. Tutkun, O Andreassen, R. Fuchs, R. Peikert, and H. Hauser, Energy-scale aware feature extraction for flow visualization, Computer Graphics Forum, 30 (2011), pp. 771-780. [5] F. Sadlo and R. Peikert, Visualizing Lagrangian coherent structures: A comparison to vector field topology, in Topology-Based Methods in Visualization II: Proc. of the 2nd TopoInVis Workshop (TopoInVis 2007), H.-C. Hege, K. Polthier, and G. Scheuermann, eds, 2009, pp. 15-29.",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Lille, France",
    url = "http://lml.univ-lille1.fr/lml/?page=33\&seminID=172"
    }
    [Bibtex]
    @MISC {Pobitzer12PacificVisTutorial,
    author = "Helwig Hauser and Alexander Kuhn and Armin Pobitzer and Maik Schulze",
    title = "Time-Dependent Flow Visualization",
    howpublished = "Tutorial at 5th IEEE PacificVis Symposium",
    month = "February",
    year = "2012",
    abstract = "Vector fields are a common representation of many kinds of dynamic phenomena in a large variety of application fields. A particularly interesting class of vector fields represent time-dependent flows, i.e., flows where the vectors change over time themselves. A lot of good and relevant research work has been done on the question of how to visualize such unsteady vector fields and an overview is presented in this tutorial. In particularly, we emphasize Lagrangian methods, space-time domain approaches, and interactive visual analysis as three interesting and promising types of methodology. The tutorial is also introduced with some general remarks, in particular also on the question of why it often is not straight forward to extend methods that originally were developed for steady flows to the domain of unsteady flows. A number of examples illustrate the overview.",
    images = "images/Pobitzer12PacificVisTutorial.png",
    thumbnails = "images/Pobitzer12PacificVisTutorial_thumb.png",
    location = "Songdo, South Korea",
    url = "http://www.semseg.eu/download/2012-02-28--TimeDepFlowVizTutorial--materials/"
    }
    [PDF] [DOI] [Bibtex]
    @ARTICLE {Solteszova12APerceptual,
    author = "Veronika \v{S}olt{\'e}szov{\'a} and Cagatay Turkay and Mark Price and Ivan Viola",
    title = "A Perceptual-Statistics Shading Model",
    journal = "Visualization and Computer Graphics, IEEE Transaction on",
    year = "2012",
    volume = "18",
    number = "12",
    pages = "2265 -2274",
    month = "Dec",
    abstract = "The process of surface perception is complex and based on several influencing factors, e.g., shading, silhouettes, occluding contours, and top down cognition. The accuracy of surface perception can be measured and the influencing factors can be modified in order to decrease the error in perception. This paper presents a novel concept of how a perceptual evaluation of a visualization technique can contribute to its redesign with the aim of improving the match between the distal and the proximal stimulus. During analysis of data from previous perceptual studies, we observed that the slant of 3D surfaces visualized on 2D screens is systematically underestimated. The visible trends in the error allowed us to create a statistical model of the perceived surface slant. Based on this statistical model we obtained from user experiments, we derived a new shading model that uses adjusted surface normals and aims to reduce the error in slant perception. The result is a shape-enhancement of visualization which is driven by an experimentally-founded statistical model. To assess the efficiency of the statistical shading model, we repeated the evaluation experiment and confirmed that the error in perception was decreased. Results of both user experiments are publicly-available datasets.",
    pdf = "pdfs/Solteszova12APerceptual.pdf",
    images = "images/Solteszova12APerceptual01.png, images/Solteszova12APerceptual02.png, images/Solteszova12APerceptual03.png",
    thumbnails = "images/Solteszova12APerceptual01_thumb.png, images/Solteszova12APerceptual02_thumb.png, images/Solteszova12APerceptual03_thumb.png",
    event = "IEEE Scientific Visualization Conference 2012",
    location = "Seattle, WA, USA",
    doi = "10.1109/TVCG.2012.188",
    issn = "1077--2626",
    extra = "extra/Solteszova12APerceptual.zip",
    project = "illustrasound,medviz,illvis"
    }
    [Bibtex]
    @MISC {Hauser12VCF,
    author = "Helwig Hauser",
    title = "The Iterative Process of Interactive Visual Analysis",
    howpublished = "Talk in the Visual Computing Forum (VCF) at UiB",
    month = "September",
    year = "2012",
    abstract = "One central characteristic of our information age is that increasingly often we should exploit the wealth of available data for the sake of learning, decision making, as well as other tasks. A promising approach - not at the least also targeted by visual analytics - is to integrate the strengths of computers (fast computation, efficient handling of large datasets, comparably low costs, etc.) with the strengths of the users (perceptual capabilities, considering domain knowledge, detecting the unexpected, etc.). In this talk, we look at one possible solution, i.e., the concept of interactive visual analysis, and describe it as an iterative process, enabling the integration of computational and interactive means for data exploration and analysis. We consider a data scenario that opposes dependent and independent data dimensions (like in a table), general enough to match many different application cases. We focus on the case of multivariate data, but also address the case of high-dimensional data and opportunities for exploring and analyzing such data. After all, we think of interactive visual analysis as an iterative process, where each step is performed on the basis of a toolbox with computational and interactive visual solutions.",
    images = "images/Hauser12VCF.jpg",
    thumbnails = "images/Hauser12VCF_thumb.jpg",
    location = "Bergen, Norway",
    url = "http://www.ii.uib.no/vis/vcf/"
    }
    [Bibtex]
    @MISC {Hauser12VisTutorial,
    author = "Steffen Oeltze and Helmut Doleisch and Helwig Hauser and Gunther Weber",
    title = "Interactive Visual Analysis of Scientific Data",
    howpublished = "Tutorial at the IEEE VisWeek 2012",
    month = "October",
    year = "2012",
    abstract = "In a growing number of application areas, a subject or phenomenon is investigated by means of multiple datasets being acquired over time (spatiotemporal), comprising several attributes per data point (multi-variate), stemming from different data sources (multi-modal) or multiple simulation runs (multirun/ensemble). Interactive visual analysis (IVA) comprises concepts and techniques for a user-guided knowledge discovery in such complex data. Through a tight feedback loop of computation, visualization and user interaction, it provides new insight into the data and serves as a vehicle for hypotheses generation or validation. It is often implemented via a multiple coordinated view framework where each view is equipped with interactive drill-down operations for focusing on data features. Two classes of views are integrated: physical views show information in the context of the spatiotemporal observation space while attribute views show relationships between multiple data attributes. The user may drill-down the data by selecting interesting regions of the observation space or attribute ranges leading to a consistent highlighting of this selection in all other views (brushing-and-linking). In this tutorial, we discuss examples for successful applications of IVA to scientific data from various fields: automotive engineering, climate research, biology, and medicine. We base our discussions on a theoretical foundation of IVA which helps the tutorial attendees in transferring the subject matter to their own data and application area. This universally applicable knowledge is complemented in a tutorial part on IVA of very large data which accounts for the tera- and petabytes being generated by simulations and experiments in many areas of science, e.g., physics, astronomy, and climate research. The tutorial further provides an overview of off-the-shelf IVA solutions. It is concluded by a summary of the gained knowledge and a discussion of open problems in IVA of scientific data.",
    images = "images/Hauser12VisTutorial.png",
    thumbnails = "images/Hauser12VisTutorial_thumb.png",
    location = "Seattle (WA), USA",
    url = "http://visweek.org/visweek/2012/tutorial/interactive-visual-analysis-scientific-data",
    pres = "pdfs/Hauser12VisTutorialPres01.pdf"
    }
    [PDF] [Bibtex]
    @MISC {Brambilla12Geilo,
    author = "Andrea Brambilla and Armin Pobitzer and Helwig Hauser",
    title = "Flow Visualization and the SemSeg project",
    howpublished = "Poster presented at the Sintef winter school 2012",
    month = "January",
    year = "2012",
    pdf = "pdfs/Brambilla12Geilo.pdf",
    images = "images/Brambilla12Geilo01.png",
    thumbnails = "images/Brambilla12Geilo01_thumb.png",
    location = "Geilo, Norway",
    url = "http://www.sintef.no/Projectweb/eVITA/Winter-Schools/2012/"
    }
    [Bibtex]
    @MISC {Hauser12SemSegWorkshop,
    author = "Helwig Hauser and Kresimir Matkovic",
    title = "Interactive Visual Analysis of Time-Dependent Flows",
    howpublished = "Presentation at the 3rd SemSeg User Forum Workshop",
    month = "February",
    year = "2012",
    images = "images/Hauser12SemSegWorkshop.png",
    thumbnails = "images/Hauser12SemSegWorkshop_thumb.png",
    location = "Magdeburg, Germany",
    url = "http://vc.cs.ovgu.de/index.php?article_id=232",
    pres = "pdfs/Hauser12SemSegWorkshop-pres.pdf",
    project = "semseg"
    }
    [PDF] [Bibtex]
    @MISC {Pobitzer12NceSubsea,
    author = "Armin Pobitzer",
    title = "The State of the Art in Flow Visualization",
    howpublished = "Invited talk at NCS Subsea Theme Meeting - Visualization for Industrial Applications",
    month = "February",
    year = "2012",
    pdf = "pdfs/Pobitzer12NceSubsea.pdf",
    images = "images/no_thumb.png",
    thumbnails = "images/no_thumb.png",
    location = "Bergen, Norway",
    url = "http://eng.ncesubsea.no/page/389/activity/1029/theme-meeting-visualization-for-industrial-applications"
    }
    [Bibtex]
    @MISC {Hauser12TAVA,
    author = "Helwig Hauser",
    title = "Compromises and Added Value in Visual Analytics",
    howpublished = "Keynote talk at the TAVA 2012 workshop",
    month = "September",
    year = "2012",
    images = "images/Hauser12TAVA.png",
    thumbnails = "images/Hauser12TAVA_thumb.png",
    location = "Graz, Austria",
    pres = "pdfs/Hauser12TAVA-slides.pdf"
    }
    [PDF] [DOI] [Bibtex]
    @ARTICLE {Ma12ScientificStorytelling,
    author = "Kwan-Liu Ma and I. Liao and J. Frazier and H. Hauser and H.-N. Kostis",
    title = "Scientific Storytelling Using Visualization",
    journal = "Computer Graphics and Applications, IEEE",
    year = "2012",
    volume = "32",
    number = "1",
    pages = "12 -19",
    month = "Jan.--Feb.",
    abstract = "Scientists frequently tell stories using visualizations of scientific data, in the process of disseminating findings to peers and the general public. However, techniques and methods for effective scientific storytelling have received little attention so far. This article explores how literary and theatrical narrative conventions can inform the design and presentation of visualizations, and discusses the challenges of adapting scientific visualizations for broader audiences. It also summarizes recent workshops' findings on the role of storytelling in visualizations, and presents several examples of successful scientific-storytelling production teams. The conclusion is that scientific storytelling deserves greater support and recognition by the visualization community.",
    pdf = "pdfs/Ma12ScientificStorytelling.pdf",
    images = "images/Ma12ScientificStorytelling01.jpg, images/Ma12ScientificStorytelling02.jpg , images/Ma12ScientificStorytelling03.jpg, ../../../_images/CGA--2012-01--Cover.png",
    thumbnails = "images/Ma12ScientificStorytelling01_thumb.jpg, images/Ma12ScientificStorytelling02_thumb.jpg , images/Ma12ScientificStorytelling03_thumb.jpg, ../../../_images/CGA--2012-01--Cover_thumb.png",
    keywords = "literary narrative convention;scientific data visualization; scientific storytelling;theatrical narrative convention;data visualisation; natural sciences computing;",
    doi = "10.1109/MCG.2012.24",
    url = "http://dx.doi.org/10.1109/MCG.2012.24",
    issn = "0272-1716"
    }
    [Bibtex]
    @MISC {Hauser12EuroVA,
    author = "Helwig Hauser",
    title = "The Iterative Process of Interactive Visual Analysis",
    howpublished = "Keynote talk at the EuroVA 2012 workshop",
    month = "June",
    year = "2012",
    abstract = "One central characteristic of our information age is that increasingly often we should exploit the wealth of available data for the sake of learning, decision making, as well as other tasks. A promising approach - not at the least also targeted by visual analytics - is to integrate the strengths of computers (fast computation, efficient handling of large datasets, comparably low costs, etc.) with the strengths of the users (perceptual capabilities, considering domain knowledge, detecting the unexpected, etc.). In this talk, we look at one possible solution, i.e., the concept of interactive visual analysis, and describe it as an iterative process, enabling the integration of computational and interactive means for data exploration and analysis. We consider a data scenario that opposes dependent and independent data dimensions (like in a table), general enough to match many different application cases. We focus on the case of multivariate data, but also address the case of high-dimensional data and opportunities for exploring and analyzing such data. After all, we think of interactive visual analysis as an iterative process, where each step is performed on the basis of a toolbox with computational and interactive visual solutions.",
    images = "images/Hauser12EuroVA.jpg",
    thumbnails = "images/Hauser12EuroVA_thumb.jpg",
    location = "Vienna, Austria",
    url = "http://www.eurova.org/previous-events/eurova-2012",
    pres = "pdfs/Hauser12EuroVA-pres.pdf"
    }
    [Bibtex]
    @BOOK {peikert12topological,
    author = "Ronald Peikert and Helwig Hauser and Hamish Carr and Raphael Fuchs",
    title = "Topological Methods in Data Analysis and Visualization II: Theory, Algorithms, and Applications",
    publisher = "Springer",
    year = "2012",
    series = "Mathematics and Visualization",
    abstract = "When scientists analyze datasets in a search for underlying phenomena, patterns or causal factors, their first step is often an automatic or semi-automatic search for structures in the data. Of these feature-extraction methods, topological ones stand out due to their solid mathematical foundation. Topologically defined structures -as found in scalar, vector and tensor fields- have proven their merit in a wide range of scientific domains, and scientists have found them to be revealing in subjects such as physics, engineering, and medicine. Full of state-of-the-art research and contemporary hot topics in the subject, this volume is a selection of peer-reviewed papers originally presented at the fourth Workshop on Topology-Based Methods in Data Analysis and Visualization, TopoInVis 2011, held in Zurich, Switzerland. The workshop brought together many of the leading lights in the field for a mixture of formal presentations and discussion. One topic currently generating a great deal of interest, and explored in several chapters here, is the search for topological structures in time-dependent flows, and their relationship with Lagrangian coherent structures. Contributors also focus on discrete topologies of scalar and vector fields, and on persistence-based simplification, among other issues of note. The new research results included in this volume relate to all three key areas in data analysis-theory, algorithms and applications.",
    images = "images/peikert12topological.png",
    thumbnails = "images/peikert12topological_thumb.png",
    isbn = "978-3-642-23175-9",
    url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-3-642-23174-2"
    }
    [PDF] [Bibtex]
    @MISC {Pobitzer12Physics,
    author = "Armin Pobitzer",
    title = "Physics-based Velocity Field Simplification for Flow Visualization",
    howpublished = "Invited talk at Minisymposium on Analysis and Representation of Large Data Sets",
    month = "February",
    year = "2012",
    abstract = "With the availability of more computing power, simulations of increasingly complex fluid flows have become possible. In the attempt to make sense of data, visualization has greatly gained importance in everyday scientific computing. Many visualization techniques do, however, suffer from a tendency to overly rich response in complex scenarios. Hence, filtering of the visual output is an important topic. In this talk we discuss how such filtering can be achieved in a physically meaningful way, giving examples from the extraction of vortices and Lagrangian coherent structures.",
    pdf = "pdfs/Pobitzer12Physics.pdf",
    images = "images/Pobitzer12Physics.png",
    thumbnails = "images/Pobitzer12Physics_thumb.png",
    location = "Madrid, Spain"
    }
    [PDF] [Bibtex]
    @PHDTHESIS {solteszova12thesis,
    author = "Veronika \v{S}olt{\'e}szov{\'a}",
    title = "Perception-Augmenting Illumination",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2012",
    month = "Aug",
    abstract = "At each stage of the visualization pipeline, the information is impeded by loss or by noise because of imprecise acquisition, storage limitations, and processing. Furthermore, it passes through the complex and not yet well understood pathways in the human visual system and finally to result into a mental image. Due to the noise that impedes the information in the visualization pipeline and the processes in the human visual system, the mental image and the real-world phenomenon do not match. From the aspect of physics, the input of the visual system is confined only to patterns of light. Illumination is therefore essential in 3D visualization for perception of visualized objects. In this thesis, several advancements for advanced volumetric lighting are presented. First, a novel lighting model that supports interactive light source placement and yields a high-quality soft shadowing effect, is proposed. The light transport is represented by conical functions and approximated with an incremental blurring operation of the opacity buffer during front-to-back slicing of the volume. Furthermore, a new perceptuallyfounded model for expressing shadows that gives a full control over the appearance of shadows in terms of color and opacity, is presented. Third, a systematic error in perception of surface slant is modeled. This knowledge is then applied to adjust an existing shading model in a manner that compensates for the error in perception. These new visualization methodologies are linked to the knowledge of perceptual psychology and the craft of illustrators, who experimented with visual-presentation techniques for centuries. The new methodologies are showcased on challenging acoustic modalities such as 3D medical ultrasound and sonar imaging.",
    pdf = "pdfs/solteszova12thesis.pdf",
    images = "images/solteszova12thesis.png",
    thumbnails = "images/solteszova12thesis_thumb.png",
    isbn = "978-82-308-2118-3"
    }
    [Bibtex]
    @ARTICLE {Birkeland12TheUltrasound,
    author = "{\AA}smund Birkeland and Veronika \v{S}olt{\'e}szov{\'a} and Dieter H{\"o}nigmann and Odd Helge Gilja and Svein Brekke and Timo Ropinski and Ivan Viola",
    title = "The Ultrasound Visualization Pipeline - A Survey",
    journal = "CoRR",
    year = "2012",
    volume = "abs/1206.3975",
    abstract = "Ultrasound is one of the most frequently used imaging modality in medicine. The high spatial resolution, its interactive nature and non-invasiveness makes it the first choice in many examinations. Image interpretation is one of ultrasounds main challenges. Much training is required to obtain a confident skill level in ultrasound-based diagnostics. State-of-the-art graphics techniques is needed to provide meaningful visualizations of ultrasound in real-time. In this paper we present the process-pipeline for ultrasound visualization, including an overview of the tasks performed in the specific steps. To provide an insight into the trends of ultrasound visualization research, we have selected a set of significant publications and divided them into a technique-based taxonomy covering the topics pre-processing, segmentation, registration, rendering and augmented reality. For the different technique types we discuss the difference between ultrasound-based techniques and techniques for other modalities.",
    images = "images/Birkeland2012TheUltrasound.png",
    thumbnails = "images/Birkeland2012TheUltrasound_thumb.png",
    url = "http://arxiv.org/abs/1206.3975",
    project = "illustrasound,medviz,illvis"
    }
    [PDF] [Bibtex]
    @ARTICLE {Helljesen12Klinisk,
    author = "Linn Emilie S{\ae}vil Helljesen and Spiros Kotopoulis and Kim Nylund and Ivan Viola and Trygve Hausken and Odd Helge Gilja",
    title = "Klinisk bruk av 3D-ultralyd",
    journal = "Kirurgen",
    year = "2012",
    volume = "2",
    pages = "118--120",
    month = "June",
    pdf = "pdfs/Helljesen12Klinisk.pdf",
    images = "images/Helljesen12Klinisk01.png, images/Helljesen12Klinisk02.png",
    thumbnails = "images/Helljesen12Klinisk01_thumb.png, images/Helljesen12Klinisk02_thumb.png",
    url = "http://www.kirurgen.no/fagstoff/teknologiutvikling/klinisk-bruk-av-3d-ultralyd",
    project = "illustrasound,medviz"
    }
    [PDF] [Bibtex]
    @PHDTHESIS {angelelli12thesis,
    author = "Paolo Angelelli",
    title = "Visual Exploration of Human Physiology: Visualizing Perfusion, Blood Flow and Aging",
    school = "Department of Informatics, University of Bergen, Norway",
    year = "2012",
    month = "Apr",
    abstract = "With the technological advancements in medical imaging, it is nowadayspossible to capture in-vivo information related to different human physiologicalsystems. Such data extends the more traditional anatomical scans,but add size, complexity and heterogeneity. In addition, while anatomydata is defined in three-dimensional space, and 3D graphics techniques canbe used to represent it on the screen, physiology information is often moreabstract, and require tailored solutions to be represented in combinationwith their anatomical context.This thesis presents solutions for visualizing selected aspects in threedomains of physiology: blood flow, perfusion and aging. With respect toblood flow, it includes a technique to enhance the side-by-side visualizationof the tubular flow in vessels. This result is achieved with a methodthat generates straightened visualizations of the flow in its context, whichcan be easily aligned and then related to each other. With respect to perfusion,this thesis includes an interactive visual analysis solution that easeand improve the exploration, segmentation and analysis of perfusion dataacquired using contrast-enhanced ultrasound. This result is achieved byusing a statistical framework to extract enhancement information, and aninteractive, correlation-based approach to classify the tissue based on similarity.Finally, with respect to aging, two solutions to help exploring largedata collections of repeated examinations are presented. In one, interactivevisual analysis methods are employed to explore and analyze cohort studydata, while the other focuses on the guided exploration of repeated ultrasoundexaminations. Demonstration case studies are include to exemplifythe utility of the presented work.",
    pdf = "pdfs/angelelli12thesis.pdf",
    images = "images/angelelli12thesis.png",
    thumbnails = "images/angelelli12thesis_thumb.png",
    isbn = "978-82-308-2073-5"
    }
    [PDF] [DOI] [VID] [Bibtex]
    @ARTICLE {Turkay12Representative,
    author = "Cagatay Turkay and Arvid Lundervold and Astri Johansen Lundervold and Helwig Hauser",
    title = "Representative Factor Generation for the Interactive Visual Analysis of High-Dimensional Data",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2012",
    volume = "18",
    number = "12",
    pages = "2621--2630",
    month = "December",
    abstract = "Datasets with a large number of dimensions per data item (hundreds or more) are challenging both for computational and visual analysis. Moreover, these dimensions have different characteristics and relations that result in sub-groups and/or hierarchies over the set of dimensions. Such structures lead to heterogeneity within the dimensions. Although the consideration of these structures is crucial for the analysis, most of the available analysis methods discard the heterogeneous relations among the dimensions. In this paper, we introduce the construction and utilization of representative factors for the interactive visual analysis of structures in high-dimensional datasets. First, we present a selection of methods to investigate the sub-groups in the dimension set and associate representative factors with those groups of dimensions. Second, we introduce how these factors are included in the interactive visual analysis cycle together with the original dimensions. We then provide the steps of an analytical procedure that iteratively analyzes the datasets through the use of representative factors. We discuss how our methods improve the reliability and interpretability of the analysis process by enabling more informed selections of computational tools. Finally, we demonstrate our techniques on the analysis of brain imaging study results that are performed over a large group of subjects.",
    pdf = "pdfs/Turkay12Representative.pdf",
    vid = "vids/Turkay12Representative.avi",
    images = "images/Turkay12Representative01.png, images/Turkay12Representative02.png",
    thumbnails = "images/Turkay12Representative01_thumb.png, images/Turkay12Representative02_thumb.png",
    event = "IEEE Information Visualization Conference 2012",
    location = "Seattle, WA, USA",
    doi = "10.1109/TVCG.2012.256",
    issn = "1077-2626"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Parulek12ImplicitRepresentation,
    author = "Julius Parulek and Ivan Viola",
    title = "Implicit Representation of Molecular Surfaces",
    booktitle = "Proceedings of the IEEE Pacific Visualization Symposium (PacificVis 2012)",
    year = "2012",
    pages = "217--224",
    month = "March",
    abstract = "Molecular surfaces are an established tool to analyze and to study the evolution and interaction of molecules. One of the most advanced representations of molecular surfaces is called the solvent excluded surface. We present a novel and a simple method for representing the solvent excluded surfaces (SES). Our method requires no precomputation and therefore allows us to vary SES parameters outright. We utilize the theory of implicit surfaces and their CSG operations to compose the implicit function representing the molecular surface locally. This function returns a minimal distance to the SES representation. Additionally, negative values of the implicit function determine that the point lies outside SES whereas positive ones that the point lies inside. We describe how to build this implicit function composed of three types of patches constituting the SES representation. Finally, we propose a method to visualize the iso-surface of the implicit function by means of ray-casting and the set of rendering parameters affecting the overall performance.",
    pdf = "pdfs/Parulek12ImplicitRepresentation.pdf",
    images = "images/Parulek12ImplicitRepresentation.png",
    thumbnails = "images/Parulek12ImplicitRepresentation_thumb.png",
    location = "Songdo, Korea",
    project = "physioillustration"
    }
    [DOI] [Bibtex]
    @ARTICLE {Schindler12Lagrangian,
    author = "Benjamin Schindler and Raphael Fuchs and Stefan Barp and Jurgen Waser and Armin Pobitzer and Robert Carnecky and Kresimir Matkovic and Ronald Peikert",
    title = "Lagrangian Coherent Structures for Design Analysis of Revolving Doors",
    journal = "Visualization and Computer Graphics, IEEE Transactions on",
    year = "2012",
    volume = "18",
    number = "12",
    pages = "2159--2168",
    month = "December",
    abstract = "Room air flow and air exchange are important aspects for the design of energy-efficient buildings. As a result, simulations are increasingly used prior to construction to achieve an energy-efficient design. We present a visual analysis of air flow generated at building entrances, which uses a combination of revolving doors and air curtains. The resulting flow pattern is challenging because of two interacting flow patterns: On the one hand, the revolving door acts as a pump, on the other hand, the air curtain creates a layer of uniformly moving warm air between the interior of the building and the revolving door. Lagrangian coherent structures (LCS), which by definition are flow barriers, are the method of choice for visualizing the separation and recirculation behavior of warm and cold air flow. The extraction of LCS is based on the finite-time Lyapunov exponent (FTLE) and makes use of a ridge definition which is consistent with the concept of weak LCS. Both FTLE computation and ridge extraction are done in a robust and efficient way by making use of the fast Fourier transform for computing scale-space derivatives.",
    images = "images/Schindler12Lagrangian01.png",
    thumbnails = "images/Schindler12Lagrangian01_thumb.png",
    doi = "10.1109/TVCG.2012.243",
    issn = "1077-2626",
    url = "http://visdom.at/person/5/"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Pobitzer12AStatistics,
    author = "Armin Pobitzer and Alan Lez and Kresimir Matkovic and Helwig Hauser",
    title = "A Statistics-based Dimension Reduction of the Space of Path Line Attributes for Interactive Visual Flow Analysis",
    booktitle = "Proceedings of the IEEE Pacific Visualization Symposium (PacificVis 2012)",
    year = "2012",
    pages = "113--120",
    month = "March",
    abstract = "Recent work has shown the great potential of interactive flow analysis by the analysis of path lines. The choice of suitable attributes, describing the path lines, is, however, still an open question. This paper addresses this question performing a statistical analysis of the path line attribute space. In this way we are able to balance the usage of computing power and storage with the necessity to not loose relevant information. We demonstrate how a carefully chosen attribute set can improve the benefits of state-of-the art interactive flow analysis. The results obtained are compared to previously published work.",
    pdf = "pdfs/Pobitzer12AStatistics.pdf",
    images = "images/Pobitzer12AStatistics.png",
    thumbnails = "images/Pobitzer12AStatistics_thumb.png",
    location = "Songdo, Korea"
    }
    [DOI] [Bibtex]
    @ARTICLE {Doleish12Interactive,
    author = "Helmut Doleisch and Helwig Hauser",
    title = "Interactive Visual Exploration and Analysis of Multivariate Simulation Data",
    journal = "Computing in Science Engineering",
    year = "2012",
    volume = "14",
    number = "2",
    pages = "70--77",
    month = "March-April",
    abstract = "The interactive visual exploration of large and complex simulation datasets has become an important methodology that improves data analysis for scientists and professional practitioners.",
    images = "images/Doleish12Interactive01.png, images/Doleish12Interactive02.png",
    thumbnails = "images/Doleish12Interactive01_thumb.png, images/Doleish12Interactive02_thumb.png",
    keywords = "complex simulation datasets;data analysis;important methodology; interactive visual exploration;multivariate simulation data;data analysis; data visualisation;geophysics computing;",
    doi = "10.1109/MCSE.2012.27",
    issn = "1521-9615",
    url = "http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6159200"
    }
    [PDF] [Bibtex]
    @INPROCEEDINGS {Lidal12Design,
    author = "Endre M. Lidal and Helwig Hauser and Ivan Viola",
    title = "Design Principles for Cutaway Visualization of Geological Models",
    booktitle = "Proceedings of Spring Conference on Computer Graphics (SCCG 2012)",
    year = "2012",
    pages = "53--60",
    month = "May",
    abstract = "In this paper, we present design principles for cutaway visualizations that emphasize shape and depth communication of the focus features and their relation to the context. First, to eliminate cutaway-flatness we argue that the cutaway axis should have an angular offset from the view direction. Second, we recommend creating a box-shaped cutaway. Such a simple cutaway shape allows for easier context extrapolation in the cutaway volume. Third, to improve the relationship between the focus features and the context, we propose to selectively align the cutaway shape to familiar structures in the context. Fourth, we emphasize that the illumination model should effectively communicate the shape and spatial ordering inside the cutaway, through shadowing as well as contouring and other stylized shading models. Finally, we recommend relaxing the view-dependency constraint of the cutaway to improve the depth perception through the motion parallax. We have identified these design principles while developing interactive cutaway visualizations of 3D geological models, inspired by geological illustrations and discussions with the domain illustrators and experts.",
    pdf = "pdfs/Lidal12Design.pdf",
    images = "images/Lidal12Design01.jpg, images/Lidal12Design02.jpg",
    thumbnails = "images/Lidal12Design01_thumb.jpg, images/Lidal12Design02_thumb.jpg",
    location = "Smolenice castle, Slovakia",
    project = "geoillustrator"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Brambilla12Illustrative,
    author = "Andrea Brambilla and Robert Carnecky and Ronald Peikert and Ivan Viola and Helwig Hauser",
    title = "Illustrative Flow Visualization: State of the Art, Trends and Challenges",
    booktitle = "EuroGraphics 2012 State of the Art Reports (STARs)",
    year = "2012",
    pages = "75--94",
    abstract = "Flow visualization is a well established branch of scientific visualization and it currently represents an invaluable resource to many fields, like automotive design, meteorology and medical imaging. Thanks to the capabilities of modern hardware, flow datasets are increasing in size and complexity, and traditional flow visualization techniques need to be updated and improved in order to deal with the upcoming challenges. A fairly recent trend to enhance the expressiveness of scientific visualization is to produce depictions of physical phenomena taking inspiration from traditional handcrafted illustrations: this approach is known as illustrative visualization, and it is getting a foothold in flow visualization as well. In this state of the art report we give an overview of the existing illustrative techniques for flow visualization, we highlight which problems have been solved and which issues still need further investigation, and, finally, we provide remarks and insights on the current trends in illustrative flow visualization.",
    pdf = "pdfs/Brambilla12Illustrative.pdf",
    images = "images/Brambilla12Illustrative.png",
    thumbnails = "images/Brambilla12Illustrative_thumb.png",
    url = "http://diglib.eg.org/EG/DL/conf/EG2012/stars/075-094.pdf",
    doi = "10.2312/conf/EG2012/stars/075-094",
    location = "Cagliari, Italy",
    pres = "pdfs/Brambilla12Illustrative.pptx",
    project = "semseg"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Lidal12Geological,
    author = "Endre M. Lidal and Helwig Hauser and Ivan Viola ",
    title = "Geological Storytelling - Graphically Exploring and Communicating Geological Sketches",
    booktitle = "Proceedings of Sketch-Based Interfaces and Modeling (SBIM 2012)",
    year = "2012",
    pages = "11--20",
    abstract = "Developing structural geological models from exploratory subsea imaging is difficult and an ill-posed process. Therefore, in practice several experts generate a larger number of geological interpretations. This leads to the situation that a number of geological sketches are prepared and examined for the next steps in the oil and gas exploration pipeline. In this paper, we present Geological Storytelling, a novel graphical approach for performing rapid and expressive geomodeling of a multitude of model variations. The solution builds on a flip-over metaphor for sketching the individual steps in a story that externalizes the mental steps the modeler performs when developing the model. The stories, through the discrete story steps, are then visualized in a Story Tree for easy access and management. This tree also provides the interface for individual story playback and examination, or comparative visualization of several stories. With our approach, the experts can rapidly sketch geological stories that both visualize the proposed model of today's geology and visualize how the expert derived this model. Presenting the model as a visual story helps the peers to evaluate the geological soundness of the model. We have developed geological storytelling in collaboration with domain experts that work with such challenges on a daily basis. Our focus of this work has been on models derived from single seismic slices. We have implemented a prototype of Geological Storytelling to demonstrate our concept and to get domain expert feedback.",
    pdf = "pdfs/Lidal12Geological.pdf",
    images = "images/Lidal12Geological01.png, images/Lidal12Geological02.png",
    thumbnails = "images/Lidal12Geological01_thumb.png, images/Lidal12Geological02_thumb.png",
    url = "http://diglib.eg.org/EG/DL/WS/SBM/SBM12/011-020.pdf",
    doi = "10.2312/SBM/SBM12/011-020",
    project = "geoillustrator"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Pobitzer12Filtering,
    author = "Armin Pobitzer and Ronald Peikert and Raphael Fuchs and Holger Theisel and Helwig Hauser",
    title = "Filtering of FTLE for Visualizing Spatial Separation in Unsteady 3D Flow",
    booktitle = "Topological Methods in Data Analysis and Visualization II",
    year = "2012",
    editor = "R. Peikert and H. Hauser and H. Carr and R. Fuchs",
    pages = "237--253",
    publisher = "Springer",
    abstract = "Texture mapping is a common method for combining surface geometry with image data, with the resulting photorealistic 3D models being suitable not only for visualisation purposes but also for interpretation and spatial measurement, in many application fields, such as cultural heritage and the earth sciences. When acquiring images for creation of photorealistic models, it is usual to collect more data than is finally necessary for the texturing process. Images may be collected from multiple locations, sometimes with different cameras or lens configurations and large amounts of overlap may exist. Consequently, much redundancy may be present, requiring sorting to choose the most suitable images to texture the model triangles. This paper presents a framework for visualization and analysis of the geometric relations between triangles of the terrain model and covering image sets. The application provides decision support for selection of an image subset optimized for 3D model texturing purposes, for non-specialists. It aims to improve the communication of geometrical dependencies between model triangles and the available digital images, through the use of static and interactive information visualisation methods. The tool was used for computer-aided selection of image subsets optimized for texturing of 3D geological outcrop models. The resulting textured models were of high quality and with a minimum of missing texture, and the time spent in time-consuming reprocessing was reduced. Anecdotal evidence indicated that an increased user confidence in the final textured model quality and completeness makes the framework highly beneficial. ",
    pdf = "pdfs/Pobitzer12Filtering.pdf",
    images = "images/Pobitzer12Filtering01.png, images/Pobitzer12Filtering02.png",
    thumbnails = "images/Pobitzer12Filtering01_thumb.png, images/Pobitzer12Filtering02_thumb.png",
    doi = "http://dx.doi.org/10.1007/978-3-642-23175-9_16",
    url = "http://dx.doi.org/10.1007/978-3-642-23175-9_16",
    project = "semseg"
    }
    [PDF] [DOI] [Bibtex]
    @INPROCEEDINGS {Solteszova12Lowest,
    author = "Veronika \v{S}olt{\'e}szov{\'a} and Linn Emilie S{\ae}vil Helljesen and Wolfgang Wein and Odd Helge Gilja and Ivan Viola",
    title = "Lowest-Variance Streamlines for Filtering of 3D Ultrasound",
    booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM 2012)",
    year = "2012",
    pages = "41--48",
    month = "Sep",
    abstract = "Ultrasound as an acoustic imaging modality suffers from various kinds of noise. The presence of noise especially hinders the 3D visualization of ultrasound data, both in terms of resolving the spatial occlusion of the signal by surrounding noise, and mental decoupling of the signal from noise. This paper presents a novel type of structurepreserving filter that has been specifically designed to eliminate the presence of speckle and random noise in 3D ultrasound datasets. This filter is based on a local distribution of variance for a given voxel. The lowest variance direction is assumed to be aligned with the direction of the structure. A streamline integration over the lowest-variance vector field defines the filtered output value. The new filter is compared to other popular filtering approaches and its superiority is documented on several use cases. A case study where a clinician was delineating vascular structures of the liver from 3D visualizations further demonstrates the benefits of our approach compared to the state of the art.",
    pdf = "pdfs/Solteszova12Lowest.pdf",
    images = "images/Solteszova12Lowest01.png, images/Solteszova12Lowest02.png",
    thumbnails = "images/Solteszova12Lowest01_thumb.png, images/Solteszova12Lowest02_thumb.png",
    location = "Norrk{\"o}ping, Sweden",
    url = "http://diglib.eg.org/EG/DL/WS/VCBM/VCBM12",
    doi = "10.2312/VCBM/VCBM12/041-048",
    project = "illustrasound,medviz,illvis"
    }
    [DOI] [Bibtex]
    @INPROCEEDINGS {Natali12Rapid,
    author = "Mattia Natali and Ivan Viola and Daniel Patel",
    title = "Rapid Visualization of Geological Concepts",
    booktitle = "SIBGRAPI 2012 (XXV Conference on Graphics, Patterns and Images)",
    year = "2012",
    editor = "C. Freitas, L. Silva, R. Scopigno, and S. Sarkar",
    address = "Ouro Preto, MG, Brazil",
    month = "August",
    abstract = "We describe a sketch-based system for constructing an illustrative visualization of the subsurface. An intuitive and rapid modelling tool is defined, which takes as input user's strokes and creates a 3D layer-cake model of the earth. Our tool enables users to quickly express and communicate their ideas directly using a 3D model. For sketching, we have created geometric operators that capture the domain specific modelling requirements.We have devised sketching operators for expressing folding and faulting processes. This makes it possible to produce a large span of scenarios. Moreover, for communicating layer properties such as rock type and grain size, our system allows for associating user defined texture to each layer which can be deformed with a few sketch strokes.",
    images = "images/Natali12Rapid01.png, images/Natali12Rapid02.png",
    thumbnails = "images/Natali12Rapid01_thumb.png, images/Natali12Rapid02_thumb.png",
    url = "http://www.decom.ufop.br/sibgrapi2012/",
    doi = "10.1109/SIBGRAPI.2012.29",
    project = "geoillustrator"
    }