DevLan/vispubs huggingface dataset:
PhylloTrees: Phyllotactic Patterns for Tree Layout
Authors: Petra Neumann 0001, Sheelagh Carpendale, Anand Agarawala
Published at EuroVis, 2006

Motivations for drawing hierarchical structures are probably as diverse as datasets to visualize. This ubiquity of tree structures has lead to a manifold of tree layout algorithms and tree visualization systems. While many tree layouts exist, increasingly massive data sets, expanding computational power, and still relatively limited display space make tree layout algorithms a topic of ongoing interest. We explore the use of nature's phyllotactic patterns to inform the layout of hierarchical data. These naturally occurring patterns provide a non-overlapping, optimal packing when the total number of nodes is not known a priori. We present PhylloTrees, a family of expandable tree layouts based on these patterns.
PointCloudXplore: Visual Analysis of 3D Gene Expression Data Using Physical Views and Parallel Coordinates
Authors: Oliver Rübel, Gunther H. Weber, Soile V. E. Keränen, Charless C. Fowlkes, Cris L. Luengo Hendriks, Lisa Simirenko, Nameeta Y. Shah, Michael B. Eisen, Mark D. Biggin, Hans Hagen, Damir Sudar, Jitendra Malik, David W. Knowles, Bernd Hamann
Published at EuroVis, 2006

To allow a more rigorous understanding of animal gene regulatory networks, the Berkeley Drosophila Transcription Network Project (BDTNP) has developed a suite of methods that support quantitative, computational analysis of three-dimensional (3D) gene expression patterns with cellular resolution in early Drosophila embryos. Here we report the first components of a visualization tool, PointCloudXplore, that allows the relationships between different gene's expression to be analyzed using the BDTNP's datasets.

PointCloudXplore uses the established visualization techniques of multiple views, brushing, and linking to support the analysis of high-dimensional datasets that describe many genes' expression. Each of the views in PointCloud- Xplore shows a different gene expression data property. Brushing is used to select and emphasize data associated with defined subsets of embryo cells within a view. Linking is used to show in additional views the expression data for a group of cells that have first been highlighted as a brush in a single view, allowing further data subset properties to be determined. In PointCloudXplore, physical views of the data are linked to parallel coordinates. Physical views show the spatial relationships between different genes' expression patterns within the embryo. Parallel coordinates, on the other hand, show only some features of each gene's expression, but allow simultaneous analysis of data for many more genes than would be possible in a physical view. We have developed several extensions to standard parallel coordinates to facilitate brushing the visualization of 3D gene expression data.
Real-Time Super Resolution Contextual Close-up of Clinical Volumetric Data
Authors: T. Taerum, Mario Costa Sousa, Faramarz F. Samavati, S. Chan, Joseph Ross Mitchell
Published at EuroVis, 2006

We present an illustrative visualization system for real-time and high quality rendering of clinical volumetric medical data. Our technique is inspired by a medical illustration technique for depicting contextual close-up views of selected regions of interest where internal anatomical features are rendered in high detail. Our method integrates four important components: decimation of original volume for interactivity, B-spline subdivision for super-resolution rendering, fast gradient quantization technique for feature extraction and GPU fragment shaders for gradient dependent rendering and transfer functions. Examples with clinical CT and MRI data demonstrate the capabilities of our system.
Robust Surface Detection for Variance Comparison and Dimensional Measurement
Authors: Christoph Heinzl, R. Klingesberger, Johann Kastner, M. Eduard Gröller
Published at EuroVis, 2006

This paper describes a robust method for creating surface models from volume datasets with distorted density values due to artefacts and noise. Application scenario for the presented work is variance comparison and dimensional measurement of homogeneous industrial components in industrial high resolution 3D computed tomography (3D-CT). We propose a pipeline which uses common 3D image processing filters for pre-processing and segmentation of 3D-CT datasets in order to create the surface model. In particular, a pre-filtering step reduces noise and artefacts without blurring edges in the dataset. A watershed filter is applied on the gradient information of the smoothed data to create a binary dataset. Finally the surface model is constructed, using constrained elastic-surface nets to generate a smooth but feature preserving mesh of a binary volume. The major contribution of this paper is the development of the specific processing pipeline for homogeneous industrial components to handle large resolution data of industrial CT scanners. The pipeline is crucial for the following visual inspection of deviations.
Segmentation of Flow Fields using Pattern Matching
Authors: Julia Ebling, Gerik Scheuermann
Published at EuroVis, 2006

Due to the amount of data nowadays, automatic detection, classification and visualization of features is necessary for a thorough inspection of flow data sets. Pattern matching using vector valued templates has already been applied successfully for the detection of features. In this paper, the approach is extended to automatically compute feature based segmentations of flow data sets. Different problems of the segmentation like the influence of thresholds, overlapping features, and classification errors are discussed. Visualizations of the segmentation display important structures of the flow and highlight the interesting features. The segmentation algorithm presented in this paper is applicable to 2D and 3D vector fields as well as to time-dependent data.
Simultaneous Classification of Time-Varying Volume Data Based on the Time Histogram
Authors: Hiroshi Akiba, Nathaniel Fout, Kwan-Liu Ma
Published at EuroVis, 2006

An important challenge in the application of direct volume rendering to time-varying data is the specification of transfer functions for all time steps. Very little research has been devoted to this problem, however. To address this issue we propose an approach which allows simultaneous classification of the entire time series. We explore options for transfer function specification that are based, either directly or indirectly, on the time histogram. Furthermore, we consider how to effectively provide feedback for interactive classification by exploring options for simultaneous rendering of the time series, again based on the time histogram. Finally, we apply this approach to several large time-varying data sets where we show that the important features at all times are captured with about the same effort it takes to classify one time step using conventional classification.
Structure-accentuating Dense Flow Visualization
Authors: Sung W. Park, Hongfeng Yu 0001, Ingrid Hotz, Oliver Kreylos, Lars Linsen, Bernd Hamann
Published at EuroVis, 2006

Vector field visualization approaches can broadly be categorized into approaches that directly visualize local or integrated flow and approaches that analyze the topological structure and visualize extracted features. Our goal was to come up with a method that falls into the first category, yet reveals structural information. We have developed a dense flow visualization method that shows the overall flow behavior while accentuating structural information without performing a topological analysis. Our method is based on a geometry-based flow integration step and a texture-based visual exploration step. The flow integration step generates a density field, which is written into a texture. The density field is generated by tracing particles under the influence of the underlying vector field. When using a quasi-random seeding strategy for initialization, the resulting density is high in attracting regions and low in repelling regions. Density is measured by the number of particles per region accumulated over time. We generate one density field using forward and one using backward propagation. The density fields are explored using texture-based rendering techniques. We generate the two output images separately and blend the results, which allows us to distinguish between inflow and outflow regions. We obtained dense flow visualizations that display the overall flow behavior, emphasize critical and separating regions, and indicate flow direction in the neighborhood of these regions. We have test our method for isolated first-order singularities and real data sets.
Terrain Rendering using Spherical Clipmaps
Authors: Malte Clasen, Hans-Christian Hege
Published at EuroVis, 2006

We describe a terrain rendering algorithm for spherical terrains based on clipmaps. It leverages the high geometry throughput of current GPU to render large static triangle sets. The vertices are displaced by a height map texture. Our main contribution is mapping of texture coordinates to calculate the height map sample position based on the static vertex offset and the variable view position.
Texture Advection on Stream Surfaces: A Novel Hybrid Visualization Applied to CFD Simulation Results
Authors: Robert S. Laramee, Christoph Garth, Jürgen Schneider, Helwig Hauser
Published at EuroVis, 2006

Stream surfaces are a classic flow visualization technique used to portray the characteristics of vector fields, and texture advection research has made rapid advances in recent years. We present a novel hybrid visualization of texture advection on stream surfaces. This approach conveys properties of the vector field that stream surfaces alone cannot. We apply the visualization technique to various patterns of flow from CFD data important to automotive engine simulation including two patterns of in-cylinder flow (swirl and tumble motion) as well as flow through a cooling jacket. In addition, we explore multiple vector fields defined at the stream surface such as velocity, vorticity, and pressure gradient. The results of our investigation highlight both the strengths and limitations of the hybrid stream surface-texture advection visualization technique and offer new insight to engineers exploring and analyzing their simulations.
The alpha -histogram: Using Spatial Coherence to Enhance Histograms and Transfer Function Design
Authors: Claes Lundström, Anders Ynnerman, Patric Ljung, Anders Persson, Hans Knutsson
Published at EuroVis, 2006

The high complexity of Transfer Function (TF) design is a major obstacle to widespread routine use of Direct Volume Rendering, particularly in the case of medical imaging. Both manual and automatic TF design schemes would benefit greatly from a fast and simple method for detection of tissue value ranges. To this end, we introduce the a-histogram, an enhancement that amplifies ranges corresponding to spatially coherent materials. The properties of the a-histogram have been explored for synthetic data sets and then successfully used to detect vessels in 20 Magnetic Resonance angiographies, proving the potential of this approach as a fast and simple technique for histogram enhancement in general and for TF construction in particular.
Visualizing the Phonon Map
Authors: Eduard Deines, Frank Michel 0001, Martin Bertram 0001, Hans Hagen, Gregory M. Nielson
Published at EuroVis, 2006

In this work we present several visualization approaches for analyzing acoustic behavior inside a room. Our methods are based on the results of the phonon tracing algorithm. For a simulated phonon map we examine the influence of the room surfaces on the wave fronts during their propagation from the sound source. Our visualization is based on individual phonon and surface representations as well as scattered data interpolation. Additionally, an observation of acoustic behavior at different positions inside the room using colored and deformed spheres is possible.
Volume Composition Using Eye Tracking Data
Authors: Aidong Lu, Ross Maciejewski, David S. Ebert
Published at EuroVis, 2006

This paper presents a method to automate rendering parameter selection, simplifying tedious user interaction and improving the usability of visualization systems. Our approach acquires regions-of-interest for a dataset with an eye tracker and simple user interaction. Based on this importance information, we then automatically compute reasonable rendering parameters using a set of heuristic rules adapted from visualization experience and psychophysics experiments. While the parameter selections for a specific visualization task are subjective, our approach provides good starting results that can be refined by the user. Our system improves the interactivity of a visualization system by significantly reducing the necessary parameter selection and providing good initial rendering parameters for newly acquired datasets of similar types.
A fisheye follow-up: further reflections on focus + context
Authors: George W. Furnas
Published at CHI, 2006

Information worlds continue to grow, posing daunting challenges for interfaces. This paper tries to increase our understanding of approaches to the problem, building on the Generalized Fisheye View framework. Three issues are discussed. First a number of existing techniques are unified by the commonality of what they show, certain fisheye-related subsets, with the techniques differing only in how they show those subsets. Then the elevated importance of these subsets, and their generality, is used to discuss the possibility of non-visual fisheye-views, to attack problems not so amenable to visualization. Finally, several models are given for why these subsets might be important in user interactions, with the goal of better informing design rationales.
Feeling what you hear: tactile feedback for navigation of audio graphs
Authors: Steven A. Wall, Stephen A. Brewster
Published at CHI, 2006

Access to digitally stored numerical data is currently very limited for sight impaired people. Graphs and visualizations are often used to analyze relationships between numerical data, but the current methods of accessing them are highly visually mediated. Representing data using audio feedback is a common method of making data more accessible, but methods of navigating and accessing the data are often serial in nature and laborious. Tactile or haptic displays could be used to provide additional feedback to support a point-and-click type interaction for the visually impaired. A requirements capture conducted with sight impaired computer users produced a review of current accessibility technologies, and guidelines were extracted for using tactile feedback to aid navigation. The results of a qualitative evaluation with a prototype interface are also presented. Providing an absolute position input device and tactile feedback allowed the users to explore the graph using tactile and proprioceptive cues in a manner analogous to point-and-click techniques.
groupTime: preference based group scheduling
Authors: Mike Brzozowski, Kendra Carattini, Scott R. Klemmer, Patrick Mihelich, Jiang Hu, Andrew Y. Ng
Published at CHI, 2006

As our business, academic, and personal lives continue to move at an ever-faster pace, finding times for busy people to meet has become an art. One of the most perplexing challenges facing groupware is effective asynchronous group scheduling (GS). This paper presents a lightweight interaction model for GS that can extend its reach beyond users of current group calendaring solutions. By expressing availability in terms of preferences, we create a flexible framework for GS that preserves plausible deniability while exerting social pressure to encourage honesty among users. We also propose an ontology that enables us to model user preferences with machine learning, predicting user responses to further lower cognitive load. The combination of visualization/direct manipulation with machine learning allows users to easily and efficiently optimize meeting times. We also suggest resulting design implications for this class of intelligent user interfaces.
GUESS: a language and interface for graph exploration
Authors: Eytan Adar
Published at CHI, 2006

As graph models are applied to more widely varying fields, researchers struggle with tools for exploring and analyzing these structures. We describe GUESS, a novel system for graph exploration that combines an interpreted language with a graphical front end that allows researchers to rapidly prototype and deploy new visualizations. GUESS also contains a novel, interactive interpreter that connects the language and interface in a way that facilities exploratory visualization tasks. Our language, Gython, is a domain-specific embedded language which provides all the advantages of Python with new, graph specific operators, primitives, and shortcuts. We highlight key aspects of the system in the context of a large user survey and specific, real-world, case studies ranging from social and knowledge networks to distributed computer network analysis.
Keepin' it real: pushing the desktop metaphor with physics, piles and the pen
Authors: Anand Agarawala, Ravin Balakrishnan
Published at CHI, 2006

We explore making virtual desktops behave in a more physically realistic manner by adding physics simulation and using piling instead of filing as the fundamental organizational structure. Objects can be casually dragged and tossed around, influenced by physical characteristics such as friction and mass, much like we would manipulate lightweight objects in the real world. We present a prototype, called BumpTop, that coherently integrates a variety of interaction and visualization techniques optimized for pen input we have developed to support this new style of desktop organization.
Minimap: a web page visualization method for mobile phones
Authors: Virpi Roto, Andrei Popescu 0003, Antti Koivisto, Elina Vartiainen
Published at CHI, 2006

The Web has become available even on mobile phones, but the current methods to view large pages on small screens have not been highly usable. Current mobile phone browsers reformat Web pages to a single column that fits the screen width. Because not all content is comprehensible in this format, browsers provide a second mode for viewing pages in the same layout as on a PC. We have developed a modeless Web page visualization method called Minimap that shows pages in a modified Original layout. We conducted a long-term usability study with 20 participants to compare the state-of-the-art mobile phone browser with this new method. 18 participants preferred the new method, and it also scored better in more detailed usability ratings.
Sashay: designing for wonderment
Authors: Eric Paulos, Chris Beckmann
Published at CHI, 2006

No longer confined to our offices, schools, and homes, technology is expanding at an astonishing rate across our everyday public urban landscapes. From the visible (mobile phones, laptops, and blackberries) to the invisible (GPS, WiFi, GSM, and EVDO), we find the full spectrum of digital technologies transforming nearly every facet of our urban experience. Many current urban computing systems focus on improving our efficiency and productivity in the city by providing "location services" and/or interactive navigation and mapping tools. While agreeing with the need for such systems, we are reminded that urban life spans a much wider range of emotions and experiences. Our claim is that our successful future urban technological tools will be those that incorporate the full range of urban experiences -- from improving productivity and efficiency to promoting wonderment and daydreaming. We discuss intervention as a research strategy for understanding wonderment; demonstrate an example of such a study using a matchbook experiment to expose relationships between locations and emotions within a city; and use the results to develop Sashay -- a mobile phone application that promotes wonderment by visualizing an individual's personal patterns across the invisible, manufactured geography of mobile phone cellular towers.
Visual exploration of multivariate graphs
Authors: Martin Wattenberg
Published at CHI, 2006

This paper introduces PivotGraph, a software tool that uses a new technique for visualizing and analyzing graph structures. The technique is designed specifically for graphs that are "multivariate," i.e., where each node is associated with several attributes. Unlike visualizations which emphasize global graph topology, PivotGraph uses a simple grid-based approach to focus on the relationship between node attributes and connections. The interaction technique is derived from an analogy with methods seen in spreadsheet pivot tables and in online analytical processing (OLAP). Finally, several examples are presented in which PivotGraph was applied to real-world data sets.
Visualization of large hierarchical data by circle packing
Authors: Weixin Wang, Henry (Hui) Wang, Guozhong Dai, Hongan Wang
Published at CHI, 2006

In this paper a novel approach is described for tree visualization using nested circles. The brother nodes at the same level are represented by externally tangent circles; the tree nodes at different levels are displayed by using 2D nested circles or 3D nested cylinders. A new layout algorithm for tree structure is described. It provides a good overview for large data sets. It is easy to see all the branches and leaves of the tree. The new method has been applied to the visualization of file systems.
Visualizing email content: portraying relationships from conversational histories
Authors: Fernanda B. Viégas, Scott A. Golder, Judith S. Donath
Published at CHI, 2006

We present Themail, a visualization that portrays relationships using the interaction histories preserved in email archives. Using the content of exchanged messages, it shows the words that characterize one's correspondence with an individual and how they change over the period of the relationship.This paper describes the interface and content-parsing algorithms in Themail. It also presents the results from a user study where two main interaction modes with the visualization emerged: exploration of "big picture" trends and themes in email (haystack mode) and more detail-oriented exploration (needle mode). Finally, the paper discusses the limitations of the content parsing approach in Themail and the implications for further research on email content visualization.
2D asymmetric tensor analysis
Authors: Xiaoqiang Zheng, Alex T. Pang
Published at Vis, 2005

Analysis of degenerate tensors is a fundamental step in finding the topological structures and separatrices in tensor fields. Previous work in this area have been limited to analyzing symmetric second order tensor fields. In this paper, we extend the topological analysis to 2D general (asymmetric) second order tensor fields. We show that it is not sufficient to define degeneracies based on eigenvalues alone, but one must also include the eigenvectors in the analysis. We also study the behavior of these eigenvectors as they cross from one topological region into another.
A contract based system for large data visualization
Authors: Hank Childs, Eric Brugger, Kathleen S. Bonnell, Jeremy S. Meredith, Mark C. Miller, Brad Whitlock, Nelson L. Max
Published at Vis, 2005

VisIt is a richly featured visualization tool that is used to visualize some of the largest simulations ever run. The scale of these simulations requires that optimizations are incorporated into every operation VisIt performs. But the set of applicable optimizations that VisIt can perform is dependent on the types of operations being done. Complicating the issue, VisIt has a plugin capability that allows new, unforeseen components to be added, making it even harder to determine which optimizations can be applied. We introduce the concept of a contract to the standard data flow network design. This contract enables each component of the data flow network to modify the set of optimizations used. In addition, the contract allows for new components to be accommodated gracefully within VisIt's data flow network system.