Danny Holten's Personal Pages

Biography

I'm a PhD candidate postdoctoral researcher (postdoc) in the Visualization Group of professor Jack van Wijk at Eindhoven University of Technology. I obtained my MSc (ir) degree in Computer Science from Eindhoven University of Technology in 2005 (with honors). Since 2005, I'm pursuing a PhD (dr) degree In 2009, I obtained my PhD (dr) degree in Computer Science in the area of Information Visualization, more specifically, in the area of Software Visualization, from the same university (note: site update from PhD candidate period to postdoc period is in progress).

If I'm not working out at the gym in my spare time, I may just as well be found reading up on science, technology, or something I consider humorous. Apart from that, I like movies, martial arts, programming, graphic art / computer-generated imagery, philosophy, games of logic, linking to Wikipedia pages, and, of course, my friends. (According to some people, I also have an unhealthy obsession regarding the collection of specific toy robots, although I disagree.) For those interested, my Myers-Briggs Type Indicator is INTP.

Research

My current research is part of the Expression of Interest project. With respect to information visualization, the aim of the Expression of Interest project is to study how interesting data aspects can be visualized in a clear way. The final goal is to develop generic models and guidelines for this, which form a basis for a number of new visualization methods and techniques.

My PhD research (thesis as pdf) was part of the SWERL Reconstructor project, which aimed at raising the state of the art in software architecture reconstruction. Of the three main issues addressed by Reconstructor - view selection and categorization, abstraction and quantification, and interactive visualization - my research was concerned with interactive visualization, i.e., "How can users be enabled to understand the large amounts of information produced using visual representations?".

To answer this question, we employed (combinations of) techniques used in the areas of information visualization, scientific visualization, and computer graphics and developed new techniques for visualizing software systems based on insight gained. The pictures below show a couple of example visualization techniques for software systems (and more generic data) that we have developed. From top to bottom, left to right: Hierarchical Edge Bundles, visual comparison of hierarchically organized data, Force-Directed Edge Bundles, visual realism for the visualization of software metrics, and a perceptually based spectral model for isotropic textures (click images for enlarged version).

ExTraVis - EXecution TRAce VISualizer

Click here to visit the subpage for ExTraVis, a downloadable, OpenGL-based software visualization tool that enables users to interactively explore and analyze program execution traces. ExTraVis is part of the Reconstructor toolset and is introduced in the ICPC 2007 paper "Understanding Execution Traces Using Massive Sequence and Circular Bundle Views" (see Publications).

Publications

= Journal, = Conference / Workshop / Symposium, = Other.

• "Force-Directed Edge Bundling for Graph Visualization" (download PDF),
  Danny Holten and Jarke J. van Wijk, 11th Eurographics/IEEE-VGTC Symposium on Visualization (Computer Graphics Forum; Proceedings of EuroVis 2009), Pages 983 - 990, 2009.
• "A User Study on Visualizing Directed Edges in Graphs" (download PDF), received best paper nomination,
  Danny Holten and Jarke J. van Wijk, 27th SIGCHI Conference on Human Factors in Computing Systems (Proceedings of CHI 2009), Pages 2299 - 2308, 2009.
• "Drawing Binary Tanglegrams: An Experimental Evaluation" (download PDF),
  Martin Nöllenburg, Markus Völker, Alexander Wolff, and Danny Holten, 11th SIAM/SIGACT Workshop on Algorithm Engineering and Experiments (Proceedings of ALENEX 2009), Pages 106 - 119, 2009.
• "Visual Comparison of Hierarchically Organized Data" (download PDF),
  Danny Holten and Jarke J. van Wijk, 10th Eurographics/IEEE-VGTC Symposium on Visualization (Computer Graphics Forum; Proceedings of EuroVis 2008), Pages 759 - 766, 2008.
• "Execution Trace Analysis through Massive Sequence and Circular Bundle Views" (download PDF),
  Bas Cornelissen, Andy Zaidman, Danny Holten, Leon Moonen, Arie van Deursen, and Jarke J. van Wijk, Elsevier Journal of Systems & Software (JSS), Vol. 81, No. 12, Pages 2252 - 2268, 2008.
• "Trace Visualization Using Hierarchical Edge Bundles and Massive Sequence Views" (download PDF),
  Danny Holten, Bas Cornelissen, and Jarke J. van Wijk, 4th IEEE International Workshop on Visualizing Software for Understanding and Analysis (Proceedings of VISSOFT 2007), Pages 47 - 54, 2007.
• "Understanding Execution Traces Using Massive Sequence and Circular Bundle Views" (download PDF),
  Bas Cornelissen, Danny Holten, Andy Zaidman, Leon Moonen, Jarke J. van Wijk, and Arie van Deursen, 15th IEEE International Conference on Program Comprehension (Proceedings of ICPC 2007), Pages 49 - 58, 2007.
• "SQuAVisiT: A Software Quality Assessment and Visualisation Toolset" (download PDF),
  Serguei Roubtsov, Alexandru Telea, and Danny Holten, 7th IEEE International Working Conference on Source Code Analysis and Manipulation (Proceedings of SCAM 2007), Pages 155 - 156, 2007.
• "Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data" (download PDF), received best paper award,
  Danny Holten, IEEE Transactions on Visualization and Computer Graphics (TVCG; Proceedings of Vis/InfoVis 2006), Vol. 12, No. 5, Pages 741 - 748, 2006.
• "A Perceptually Based Spectral Model for Isotropic Textures" (download PDF),
  Danny Holten, Jarke J. van Wijk, and Jean-Bernard Martens, ACM Transactions on Applied Perception, Vol. 3, No. 4, Pages 376 - 398, 2006 (original formatting with high-resolution images).
• "Visual Realism for the Visualization of Software Metrics" (download PDF),
  Danny Holten, Roel Vliegen, and Jarke J. van Wijk, 3rd IEEE International Workshop on Visualizing Software for Understanding and Analysis (Proceedings of VISSOFT 2005), Pages 27 - 32, 2005.
• "Texture Synthesis for Data Visualization" (download PDF),
  Danny Holten, MSc Thesis, Technische Universiteit Eindhoven, 2005.

Posters

• "Software Visualization: Visualizing Structure, Relations, and Visual Software Comparison" (download PDF; A1 format),
  Danny Holten and Jarke J. van Wijk, LaQuSO VVSS (Verification and Validation of Software Systems) 2008 Symposium, Technische Universiteit Eindhoven, 2008.
• "Visual Comparison of Software Hierarchies" (download PPT; A0 format),
  Danny Holten and Jarke J. van Wijk, SIREN Scientific ICT-Research Event Netherlands, Technische Universiteit Delft, 2007.
• "Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data" (download PDF; A0 format),
  Danny Holten and Jarke J. van Wijk, SIREN Scientific ICT-Research Event Netherlands, Universiteit Utrecht, 2006.
• "Visual Realism for the Visualization of Software Metrics" (download PDF; A0 format),
  Danny Holten, Roel Vliegen, and Jarke J. van Wijk, SIREN Scientific ICT-Research Event Netherlands, Technische Universiteit Eindhoven, 2005.
• "Custom A0 Poster Template" (download zipped AI; Adobe Illustrator format),
  Danny Holten, Technische Universiteit Eindhoven, 2005 (special thanks to Cas Cremers for providing the photographs).

Teaching

• Masterclass Computer Graphics en Visualisatie,
  
  • One-day Dutch Masterclass for high-school students (klas 4 en 5 VWO) on the topics of Computer Graphics and Visualization. If you (or your high-school) is interested in attending or would like to receive more information, please contact me at d.h.r.holten<insert "@" here>tue.nl.
• 2IV10 "Computergrafiek 1" ("Computer Graphics 1"),
  • Course material, exercises and the evaluation thereof can be found at Dennie's site.
• 2Z830 "Programmeren 2 voor Wiskunde" ("Java Programming 2 for Math Students"),
  • Course material, exercises and the evaluation thereof can be found at Dennie's site.
• 2Z820 "Programmeren 1 voor Wiskunde" ("Java Programming 1 for Math Students"),
  • Course material, exercises and the evaluation thereof can be found at Dennie's site.

Honors & Awards

• Graduated with honors (MSc (ir), 2005).
• Received best paper award for "Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data", Danny Holten, IEEE Transactions on Visualization and Computer Graphics (TVCG; Proceedings of Vis / InfoVis 2006), Vol. 12, No. 5, Pages 741 - 748, 2006.
• Nominated for best paper award for "A User Study on Visualizing Directed Edges in Graphs", Danny Holten and Jarke J. van Wijk, 27th SIGCHI Conference on Human Factors in Computing Systems (Proceedings of CHI 2009), Pages 2299 - 2308, 2009.

Miscellaneous - Personal, projects, and pastime

• Obligatory cat rabbit pictures ("Binky") and a picture from my MSc graduation (Jack, dad, and me).
• Some pictures of the Eindhoven PhD candidates at the 2006 ASCI Conference.
• Fellow (former) PhD candidates from Eindhoven and Delft: (Bas), Bas (yes, again), (Dennie), (Hannes), Jing, Mickeal (send me a link when it's up), (Muck), Niels, and Yedendra.
• An experiment regarding the use of color-related search terms as input for Google Image Search (created before the option to search for images in a specific color was introduced).
  
  

Links - External sources of interest

= (Information) Visualization, = Graphics and Design, = Leisure, = Technology.

• Visual Complexity. A visual exploration on mapping complex networks.
• Information Aesthetics. Form follows data - data visualization and visual design.
• EagerEyes.org. All Things Visual. A website about visualization, art, visual thinking, aesthetics, and the connections between them.
• InfoVis:Wiki. The Information Visualization community platform. The InfoVis:Wiki project is intended to provide a community platform and forum integrating recent developments and news on all areas and aspects of Information Visualization.
• Prefuse. Prefuse is a set of software tools for creating rich interactive data visualizations. The prefuse information visualization toolkit provides a visualization framework for the Java programming language.
• Flare. The prefuse flare toolkit provides visualization and animation tools for the web using ActionScript and Adobe Flash.
• Quaternion Julia Sets on the GPU. The quaternion Julia set is a four-dimensional version of the Julia set fractal; playing with a small number of parameters results in a huge number of complex, beautiful shapes.
• BrandsOfTheWorld.com. A large collection of brands, logos and logotypes in vector format.
• DaFont.com. Download free and shareware fonts.
• StumbleUpon. Channel surf the internet with the StumbleUpon toolbar to find great websites, videos, photos and more based on your interests. StumbleUpon learns what you like and makes better recommendations.
• Scene.org. Scene.org cannot be explained in just a few words. On one hand it is the central source for the demoscene community but on the other hand it is an online digital community, consisting of several talented individuals across the world with the desire of creating something for the scene.
• Think Geek. Stuff for Smart Masses.
• PhD Comics. Piled Higher and Deeper. Life (or the lack thereof) in Academia.
• Despair, Inc. Soul-crushingly depressing Demotivators® designs, so you can skip the delusions that motivational products induce and head straight for the disappointments that follow.
• Ban Comic Sans Putting the "Sans" in Comic Sans. The source for anti-Comic Sans propaganda.
• Zero Punctuation The groundbreaking video review series starring Ben "Yahtzee" Croshaw.
• Cuda Zone. NVIDIA CUDA technology is a C language environment that unlocks the processing power of the GPU to solve complex compute-intensive problems.
• ATI Stream Technology. ATI Stream technology is a set of advanced hardware and software technologies that enable ATI GPU's, working in concert with the system’s CPU, to accelerate many applications beyond just graphics.
• GPGPU. The goal of GPGPU.org is to catalog the current and historical use of GPUs for general-purpose computation, and to provide a central resource for GPGPU software developers.

Copyright © 2005 - 2009 by Danny Holten. All Rights Reserved.
Last updated: 17 June 2009.