SIMON WALK

POST-DOCTORAL SCHOLAR


STANFORD UNIVERSITY

Stanford Center for Biomedical Informatics Research
1265 Welch Rd
Stanford, CA 94305

Phone: +1 (650) 495 - 9782
Email: walk@stanford.edu
Interests: Dynamical Systems & Complex Networks, Diffusion Processes on Networks and Agent-based Simulations, Knowledge & Data Mining, Social Network Analysis and Semantic Web & Ontologies
About Me
Simon Walk is a Post-Doctoral Scholar at the Stanford Center for Biomedical Informatics Research at Stanford University. Prior, he was employed as University Assistant at the Institute for Interactive Systems and Data Science (ISDS) at Graz University of Technology, which is also where he got his PhD in Computer Science in 2016. From 2012 to 2013, he was working as a scientific developer at the Know-Center GmbH and as a project assistant at the Knowledge Management Institute at Graz University of Technology. From 2013 to 2014, Simon Walk worked as a scientific developer at Virtual World Services GmbH. Additionally, he has been a visiting researcher at the Stanford Center for Biomedical Informatics Research at Stanford University (CA, USA) from November 2011 to February 2012 and September 2013 to December 2013. In 2014, he started to work as a University Assistant at the Institute for Interactive Systems and Data Science at Graz University of Technology until he started his Post-Doctoral appointment at Stanford University in 2015.

The main research interests of Simon Walk include Dynamical Systems & Complex Networks, Diffusion Processes on Networks and Agent-based Simulations, Knowledge & Data Mining, Social Network Analysis and Semantic Web & Ontologies.
Publications

JOURNAL PUBLICATIONS

  1. S. Walk, D. Helic, F. Geigl and M. Strohmaier (2016). Activity Dynamics in Collaboration Networks. ACM Transactions on the Web (TWEB) 10(2):11. [PDF] [arXiv] [ACM DL]
  2. S. Walk, P. Singer, M. Strohmaier, D. Helic, N. F. Noy and M. A. Musen (2015). How to apply Markov chains for modeling sequential edit patterns in collaborative ontology-engineering projects. International Journal of Human-Computer Studies 84, 51-66. [PDF] [arXiv]
  3. S. Walk, P. Singer, M. Strohmaier, T. Tudorache, M. A. Musen and N. F. Noy (2014). Discovering Beaten Paths in Collaborative Ontology-Engineering Projects Using Markov Chains. Journal of biomedical informatics 51, 254-271. [PDF] [arXiv]
  4. S. Walk, J. Pöschko, M. Strohmaier, K. Andrews, T. Tudorache, N. F. Noy, C. Nyulas and M. A. Musen (2013). Pragmatix: An Interactive Tool for Visualizing the Creation Process Behind Collaboratively Engineered Ontologies. International journal on Semantic Web and information systems 9 (1), 45. [PDF]
  5. M. Strohmaier, S. Walk, J. Pöschko, D. Lamprecht, T. Tudorache, C. Nyulas, M. A. Musen and N. F. Noy (2013). How Ontologies are Made: Studying the Hidden Social Dynamics Behind Collaborative Ontology-Engineering Projects. Web Semantics: Science, Services and Agents on the World Wide Web, 20, 18-34. [PDF]

CONFERENCE PUBLICATIONS

  1. S. Walk, L. Espín-Noboa, D. Helic, M. Strohmaier and M. A. Musen (2017). How Users Explore Ontologies on the Web: A Study of NCBO's BioPortal Usage Logs. In Proceedings of 26th International World Wide Web Conference WWW'17 [PDF] [arXiv]
  2. F. Geigl, S. Walk, M. Strohmaier and D. Helic (2016). Steering the Random Surfer on Directed Webgraphs. In Proceedings of IEEE/WIC/ACM International Conference on Web Intelligence WI2016 [PDF]
  3. F. Geigl, K. Lerman, S. Walk, M. Strohmaier and D. Helic (2016). Assessing the Navigational Effects of Click Biases and Link Insertion on the Web. In Proceedings of the 27th ACM Conference on Hypertext and Social Media HT '16 [PDF] [arXiv]
  4. M. Vitiello, S. Walk, R. Hernández, D. Helic and C. Gütl (2016). Classifying Students to improve MOOC dropout rates. In Proceedings of the European Stakeholder Summit on experiences and best practices in and around MOOCs (EMOOCS 2016), 501-508. [PDF]
  5. D. Lamprecht, F. Geigl, T. Karas, S. Walk, D. Helic and M. Strohmaier (2015). Improving Recommender System Navigability Through Diversification: A Case Study of IMDb. In Proceedings of the 15th International Conference on Knowledge Technologies and Data-driven Business, 21:1-21:8. [PDF]
  6. F. Geigl, D. Lamprecht, R. Hofmann-Wellenhof, S. Walk, M. Strohmaier and D. Helic (2015). Random Surfers on a Web Encyclopedia. In Proceedings of the 15th International Conference on Knowledge Technologies and Data-driven Business, 5:1-5:8. [PDF]
  7. S. Walk, P. Singer, L. E. Noboa, T. Tudorache, M. A. Musen and M. Strohmaier (2015). Understanding How Users Edit Ontologies: Comparing Hypotheses About Four Real-World Projects. In Proceedings of the 14th International Semantic Web Conference 2015, 551-568. [PDF]
  8. S. Walk, P. Singer, M. Strohmaier (2014). Sequential Action Patterns in Collaborative Ontology-Engineering Projects: A Case-Study in the Biomedical Domain. In Proceedings of the 23rd ACM International Conference on Information and Knowledge Management (CIKM), 1349-1358. [PDF]
  9. S. Walk, M. Strohmaier, T. Tudorache, N. F. Noy, C. Nyulas and M. A. Musen (2012). Recommending Concepts to Experts: An Exploration of Recommender Techniques for Collaborative Ontology Engineering Platforms in the Biomedical Domain. In Proceedings of the 3rd International Conference on Biomedical Ontology (ICBO 2012), Graz, Austria, 2012. [PDF]

WORKSHOP PUBLICATIONS

  1. T. Santos, S. Walk and D. Helic (2017). Nonlinear Characterization of Activity Dynamics in Online Collaboration Websites. In Proceedings of the 7th Temporal Web Analytics Workshop. [PDF]
  2. P. Koncar, S. Walk, D. Helic and M. Strohmaier (2017). Exploring the Impact of Trolls on Activity Dynamics in Real-World Collaboration Networks. In Proceedings of the 7th Temporal Web Analytics Workshop. [PDF]
  3. S. Walk, T. Tudorache and M. A. Musen (2016). Visualizing User Editing Behavior in Collaborative Ontology-Engineering Projects. In Proceedings of the 2nd International Workshop on Visualization and Interaction for Ontologies and Linked Data. [PDF] [Slides]
  4. S. Walk and M. Strohmaier (2014). Characterizing and Predicting Activity in Semantic MediaWiki Communities. Proceedings of the Third International Conference on Semantic Web Collaborative Spaces, 1275:54-67. [PDF]
  5. D. Kowald, S. Dennerlein, D. Theiler, S. Walk and C. Trattner (2013). The Social Semantic Server: A Framework to Provide Services on Social Semantic Network Data. I-Semantics, Graz, Austria, 2013. [PDF]

TALKS & PRESENTATIONS

  1. S. Walk (2016). Activity Dynamics in Collaboration Networks. Presented at 2016 Conference on Complex Systems (CCS2016), Beurs van Berlage, Amsterdam, NL. [Slides]
  2. S. Walk (2016). Extracting and Analyzing Sequential Interaction-Patterns. Presented at Protégé Research Meeting, Stanford, USA. [Slides]
Activities

RESEARCH VISITS

  • 05/2016 – 05/2017 Post-Doctoral Scholar at Stanford Biomedical Informatics Research Center (BMIR)
  • 09/2013 – 12/2013 Visiting Researcher at Stanford Center for Biomedical Informatics Research (BMIR)
  • 11/2011 – 02/2012 Visiting Researcher at Stanford Center for Biomedical Informatics Research (BMIR)

TEACHING

CONFERENCE PROGRAM COMMITTEE MEMBER

  • 28th ACM Conference on Hyptertext and Social Media - Social Networks & Digital Humanities Track ACM Hypertext 2017
  • 14th Extended/European Semantic Web Conference - Research Track ESWC2017
  • 25th World Wide Web Conference - Posters & Demos WWW16
  • 15th International Semantic Web Conference - Resources Track ISWC2016
  • 14th International Semantic Web Conference - Evaluation Track ISWC2015
  • 14th International Semantic Web Conference - Posters & Demos ISWC2015
  • WebSci Conference 2014 WebSci 2014
  • 13th International Semantic Web Conference - Posters & Demos ISWC2014

SUBREVIEWER

  • 15th International Semantic Web Conference - Research Track ISWC2016
  • 4th Workshop on USage Analysis and the Web of Data USEWOD2014
  • 23rd International World Wide Web Conference - Web Science Track WWW WebSci 2014
  • 11th European Semantic Web Conference ESWC 2014
  • 14th International Conference on Web Engineering ICWE 2014
  • 8th International Conference on Weblogs and Social Media ICWSM-14
  • 13th International Semantic Web Conference ISWC2014
  • 24th ACM Conference on Hypertext and Social Media Hypertext2013
  • 7th ACM Conference on Recommender Systems RecSys 2013
  • 3rd International Workshop on Mining Ubiquitous and Social Environments MUSE2012
Research
My main research interests include Knowledge & Data Mining, Social Network Analysis, Semantic Web & Ontologies as well as Dynamical Systems & Complex Networks.

OPEN PROJECTS


If you are looking for a Bachelor's or Master's project/thesis you can browse the projects that I would be interested in supervising here. If you have your own project idea, I am very happy to discuss your ideas. Just drop me a line (e-mail) and we will arrange a meeting.

STUDENTS


I would like to thank all the students who currently work or worked with me on interesting research topics: Lukas Eberhard, Tomas Karas, Patrick Kasper, Philipp Koncar, Tiago Santos and Massimo Vitiello.
Grants & Awards
I was involved in the acquisition of the following grants:
  • 2015 Competitive Initial Funding Program F&T Haus - Graz University of Technology (10,000€)
  • 2013 Marshallplan Stipend for a research visit (6,000€)