Dr Stephen Kobourov

My main research interests are in the design and implementation of efficient geometric algorithms with applications in information visualization, graph drawing, and human-computer interaction. Recently I have been working on large inter-disciplinary projects which rely on a new map-based visualization.

Recent Publications:

Felice De Luca, Iqbal Hossain, Stephen Kobourov, Katy Börner: Multi-level tree based approach for interactive graph visualization with semantic zoom. arXiv:1906.05996.

Stephen A Rains, Melanie D Hingle, Mihai Surdeanu, Dane Bell, Stephen Kobourov: A test of the risk perception attitude framework as a message tailoring strategy to promote diabetes screening. Journal of health communication, 34(6), 672-679, 2019.

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, Richard Spence: A General Framework for Multi-level Subsetwise Graph Sparsifiers. arXiv:1905.00536.

Dr Faryad Darabi Sahneh

My main research interests include network theory, graph algorithms, dynamical systems and control mathematical modeling.

Recent Publications:

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, Richard Spence: A General Framework for Multi-level Subsetwise Graph Sparsifiers. arXiv:1905.00536.

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, Richard Spence: Approximation algorithms and an integer program for multi-level graph spanners. arXiv:1904.01135.

Faryad Darabi Sahneh, Alon Efrat, Stephen Kobourov, Richard Spence: Computing Vertex-Weighted Multi-Level Steiner Trees. arXiv:1811.11700.

Dr Radoslav Fulek

The general area of my research is studying combinatorial properties of arrangements of basic geometric objects such as points, lines, polygons, polyhedra, discs, convex sets etc. motivated mainly by computational problems. Closely related to this, I am interested in topological graph theory, which can be regarded as the study of arrangements of curves on a fixed set of endpoints.

Recent Publications:

Radoslav Fulek, János Pach, Thrackles: An improved upper bound. Discrete Applied Mathematics 259: 226-231 (2019).

Radoslav Fulek, Bernd Gärtner, Andrey Kupavskii, Pavel Valtr, Uli Wagner, The Crossing Tverberg Theorem. SoCG 2019: 38:1-38:13.

Radoslav Fulek, Jan Kyncl, Z_2-Genus of Graphs and Minimum Rank of Partial Symmetric Matrices. SoCG 2019: 39:1-39:16.

Dr Md Iqbal Hossain

Md Iqbal Hossain is a research scientist of Computer Science department at University of Arizona. Dr. Hossain earned a Ph.D. in Computer Science and Engineering from Bangladesh University of Engineering and Technology (BUET). His areas of expertise include network analysis and visualization, design and analysis of algorithms, natural language processing (NLP) and machine learning (ML). He works on UAMAP: Knowledge map of University of Arizona. UAMAP project analyzes and visualizes research contributions, funds, collaborations, and citations of different universities in the US.

Recent Publications:

Felice De Luca, Md Iqbal Hossain, Stephen Kobourov: Symmetry Detection and Classification in Drawings of Graphs. arXiv:1907.01004, 2019.

Felice De Luca, Iqbal Hossain, Stephen Kobourov, Katy Börner: Multi-level tree based approach for interactive graph visualization with semantic zoom. arXiv:1906.05996.

Randy Burd, Kimberly Andrews Espy, Md Iqbal Hossain, Stephen Kobourov, Nirav Merchant, Helen Purchase: GRAM: global research activity map. Proceedings of the 2018 International Conference on Advanced Visual Interfaces, 2018.

Felice De Luca, Md Iqbal Hossain, Stephen Kobourov, Anna Lubiw, Debajyoti Mondal: Recognition and Drawing of Stick Graphs. International Symposium on Graph Drawing and Network Visualization, 303-316, 2018.

Md Iqbal Hossain, Stephen Kobourov, Helen Purchase, Mihai Surdeanu; REMatch: Research Expert Matching System. International Symposium on Big Data Visual and Immersive Analytics (BVDA), 2018.

Dr Vahan Huroyan

My main research interests include machine learning, data analysis and computer vision.

Recent Publications:

Hang Chen, Utkarsh Soni, Yafeng Lu, Vahan Huroyan, Ross Maciejewski, Stephen Kobourov: Same Stats, Different Graphs (Graph Statistics and Why We Need Graph Drawings). arXiv:1808.09913, 2018.

Vahan Huroyan, Gilad Lerman, Hau-Tieng Wu: Solving Jigsaw Puzzles By The Graph Connection Laplacian. arXiv:1811.03188, 2018.

Vahan Huroyan, Gilad Lerman: Distributed robust subspace recovery. SIAM Journal on Scientific Computing, 2018.

Dr Raymundo Navarrete

My main research interests include statistics and numerical analysis.

Recent Publications:

Raymundo Navarrete, Divakar Viswanath: Delay embedding of periodic orbits using a fixed observation function. DOI: 10.1016/j.physd.2018.11.009, 2018.

Raymundo Navarrete, Divakar Viswanath: Prevalence of Delay Embeddings with a Fixed Observation Function. 2018.

Raymundo Navarrete, Divakar Viswanath: Prediction of dynamical time series using kernel based regression and smooth splines. Electronic Journal of Statistics, 2017.

Reyan Ahmed

My main research interests include data science, algorithms and visualization.

Recent Publications:

Abu Reyan Ahmed, Md. Saidur Rahman, Stephen Kobourov, Online facility assignment, Theoretical Computer Science, 2019, ISSN 0304-3975, https://doi.org/10.1016/j.tcs.2019.08.011.

Sabin Devkota, Reyan Ahmed, Felice De Luca, Kate Isaacs, Stephen Kobourov. Stress-Plus-X (SPX) Graph Layout, arXiv:1908.01769, ccepted in the 27th International Symposium on Graph Drawing and Network Visualization (GD 2019).

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, and Richard Spence: A general framework for multi-level subsetwise graph sparsifiers. arXiv:1905.00536, 2019.

Ahmad Musa

I am a second year PhD student. My research interests are in Machine Learning and Natural Language Processing. Currently, I am working on a project named "Twitter4food". The goal of our project is to predict health risks (diabetes) from tweets using machine learning techniques and also to explore various food trends on twitter to gain a overall perspective on the food habits.

Richard Spence

My main research interests include graph algorithms, multi-level graph problems, computational complexity theory and computer graphics.

Recent Publications:

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, and Richard Spence: A general framework for multi-level subsetwise graph sparsifiers. arXiv:1905.00536, 2019.

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, and Richard Spence: Approximation algorithms and an integer program for multi-level graph spanners. arXiv:1904.01135, 2019.

Faryad Darabi Sahneh, Alon Efrat, Stephen Kobourov, Richard Spence: Computing Vertex-Weighted Multi-Level Steiner Trees. arXiv:1811.11700.

Dr Keaton Hamm

My main research interests include data science, harmonic analysis and approximation theory.

Recent Publications:

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, Richard Spence: A General Framework for Multi-level Subsetwise Graph Sparsifiers. arXiv:1905.00536.

Reyan Ahmed, Keaton Hamm, Mohammad Javad Latifi Jebelli, Stephen Kobourov, Faryad Darabi Sahneh, Richard Spence: Approximation algorithms and an integer program for multi-level graph spanners. arXiv:1904.01135.

Keaton Hamm, Longxiu Huang: CUR Decompositions, Approximations, and Perturbations. arXiv:1903.09698

Hang Chen

My main research interests include text mining, network science and graph algorithms.

Recent Publications:

Hang Chen, Utkarsh Soni, Yafeng Lu, Ross Maciejewski, Stephen Kobourov: Same Stats, Different Graphs. International Symposium on Graph Drawing and Network Visualization, 2018.

Dr Felice De Luca

My main research interests include information visualization, algorithms engineering, graph drawing and graph theory.

Recent Publications:

Felice De Luca, Iqbal Hossain, Stephen Kobourov, Katy Börner: Multi-level tree based approach for interactive graph visualization with semantic zoom. arXiv:1906.05996.

Felice De Luca, Stephen Kobourov, Helen Purchase: Perception of Symmetries in Drawings of Graphs. International Symposium on Graph Drawing and Network Visualization, 2018.

Felice De Luca, Md Iqbal Hossain, Stephen Kobourov, Anna Lubiw, Debajyoti Mondal: Recognition and Drawing of Stick Graphs. International Symposium on Graph Drawing and Network Visualization, 2018.

Dr Joe Fowler

My main research interests include graph drawing and visualization, computational geometry, sensor networks, and graph-based algorithms.

Recent Publications:

J. Joseph Fowler: Strongly-Connected Outerplanar Graphs with Proper Touching Triangle Representations. Graph Drawing 2013: 155-160

J. Joseph Fowler, Stephen G. Kobourov: Planar Preprocessing for Spring Embedders. Graph Drawing 2012: 388-399

Ulrik Brandes, Cesim Erten, Alejandro Estrella-Balderrama, J. Joseph Fowler, Fabrizio Frati, Markus Geyer, Carsten Gutwenger, Seok-Hee Hong, Michael Kaufmann, Stephen G. Kobourov, Giuseppe Liotta, Petra Mutzel, Antonios Symvonis: Colored Simultaneous Geometric Embeddings and Universal Pointsets. Algorithmica 60(3): 569-592 (2011)

Dr Sergey Pupyrev

My research interests are centered on graph drawing and graph algorithms. More interests: social network analysis, computational geometry, recommendation systems.

Recent Publications:

Lukas Barth, Sara Irina Fabrikant, Stephen G. Kobourov, Anna Lubiw, Martin Nollenburg, Yoshio Okamoto, Sergey Pupyrev, Claudio Squarcella, Torsten Ueckerdt, and Alexander Wolff. Semantic Word Cloud Representations: Hardness and Approximation Algorithms. Latin American Theoretical INformatics (LATIN'14), Accepted to appear in 2014.

Martin Fink and Sergey Pupyrev. Metro-Line Crossing Minimization: Hardness, Approximations, and Tractable Cases. 21st International Symposium on Graph Drawing (GD'13), Accepted to appear in 2013.

Sergey Bereg, Alexander E. Holroyd, Lev Nachmanson, and Sergey Pupyrev. Drawing Permutations with Few Corners. 21st International Symposium on Graph Drawing (GD'13), Accepted to appear in 2013.

Dr Paolo Simonetto

My current research interests are graph drawing and the generation of maps and diagrams.

I am part of the Gama Group (Graph and Maps Algorithms), supervised by Stephen Kobourov. I am also working on a ONR (Office of Naval Research) project for the development of a security visualisation software.

For most of my software, I use the graph drawing platform Tulip. Tulip is released under GPL licence and can be freely downloaded from SourceForge.

Recent Publications:
Paolo Simonetto, Pierre-Yves Koenig, Faraz Zaidi, Daniel Archambault et al. Solving the Traffic and Flitter Challenges with Tulip IEEE Symposium on Visual Analytics Science and Technology 2009 (VAST09). October 2009, Atlantic City.

Paolo Simonetto and David Auber An Heuristic for the Construction of Intersection Graphs 13th International Conference on Information Visualisation (IV09). July 2009, Barcelona.

Romain Bourqui, Frederic Gilbert, Paolo Simonetto, Faraz Zaidi, Umang Sharan and Fabien Jourdan
Detecting Structural Changes and Command Hierarchies in Dynamic Social Networks
2009 International Conference on Advances in Social Networks Analysis and Mining (ASONAM09). July 2009, Athens.

Muhammad Jawaherul Alam

My current research interests are Graph Drawing, Graph Algorithms, Computational Geometry.

Recent Publications:

Md. Jawaherul Alam, Michael Kaufmann, Stephen Kobourov and Tamara Mchedlidze, "Fitting Planar Graphs on Planar Maps", Journal of Graph Algorithms and Applications (JGAA), Accepted, to appear in 2014.

Md. Jawaherul Alam, Stephen Kobourov, Sergey Pupyrev and Jackson Toeniskoetter, "Happy Edges: Threshold-Coloring of Regular Lattices", 7th International Conference on Fun with Algorithms (FUN), pp. 28-39, 2014.

Md. Jawaherul Alam, David Eppstein, Michael Goodrich, Stephen Kobourov and Sergey Pupyrev, "Balanced Circle Packings for Planar Graphs", 22nd International Symposium on Graph Drawing (GD), pp. 125-136, 2014.

Daniel Fried

I am interested in information extraction, natural language processing, visualization, and machine learning. Our Maps of Computer Science system produces visualizations of topics taken from millions of Computer Science research papers, and allows interactive querying and profiling of authors, venues, and time frames.
Recent Publications:

D. Fried and S. Kobourov: "Maps of Computer Science." IEEE Pacific Visualization Symposium (PacificVis), 2014 (to appear).

D. Fried, Z. Li, A. Jannesari and F. Wolf. "Predicting parallelization of sequential programs using supervised learning." 12th International Conference on Machine Learning and Applications, 2013.

C. Dawson, J. Wright, A. Rebguns, M. Esc arcega, D. Fried and P. Cohen: "A generative probabilistic framework for learning spatial language." IEEE International Conference on Development and Learning, 2013

Sabrina Nusrat

I am currently working on implementing and evaluating various algorithms for visualization of cartograms.

Recent Publications:

Sabrina Nusrat and Stephen G. Kobourov, "Visualizing Cartograms: Goals and Task Taxonomy", submitted to: Eurographics Conference on Visualization (EuroVis 2015).

Sabrina Nusrat and Julita Vassileva, "Simulating a Trust-based Service Recommender System for Decentralized User Modeling Environment", International Journal of Trust Management in Computing and Communications (IJTMCC), Vol. 1, No. 2, 2013.

Ernesto Brau, Sabrina Nusrat, Andrew Predoehl, and Kobus Barnard, "Tracking Fluorescently-Labeled Pollen Tubes Growing in Vitro" (in preparation).

Bahador Saket

I am a PhD candidate in Computer Science department at the University of Arizona. I am working on problems in Human Computer Interaction and Information Visualization under the supervision of Dr. Stephen G. Kobourov. Previously, I completed my B.Sc. in Computer Science from Multimedia University (MMU).

Recent Publications:

Saket B., Yang S., Hong Z. Tan., Yatani K., Edge D. TalkZones: Section-based Time Support for Presentations, Submitted to the 10th International conference on Designing Interactive Systems (DIS ‘14), Vancouver.

Saket B., Prasojo C., Zhao S. Designing an Effective Vibration-Based Notification Interface for Mobile Phones, In Proc. 16th International Conference on Computer Supported Cooperative Work and Social Computing (CSCW ‘13), San Antonia, Texas .(6 Pages)

Saket B., Lim T. Y., Behrang F. Toward Emotional Design: An Exploratory Study of iPhone 4, In Proc. 4th International Conference on Applied Human Factors and Ergonomics (AHFE ‘12), July 2010, USA. (10 Pages)

Jackson Day Toeniskoetter

My research interest are on the Threshold Coloring and L-Contact graph problems. I have been making a game for FUN (webpage)

Sankar Veeramoni

My current research interests are Graph Drawing, Graph Algorithms, Computational Geometry.

Recent Publications:

A. Das, K. Fleszar, S. Kobourov, J. Spoerhase, S. Veeramoni, and A. Wolff. Approximating the Generalized Minimum Manhattan Network Problem 24th International Symposium on Algorithms and Computation (ISAAC), 2013. Slides

Y. Hu, S. G. Kobourov, and S. Veeramoni, "Embedding, Clustering and Coloring for Dynamic Maps." 5th IEEE Pacific Visualization Symposium (PacificVis), p. 33-40, 2012. Slides

Y. Hu, S. G. Kobourov, and S. Veeramoni, "On Maximum Differential Graph Coloring," 18th Symposium on Graph Drawing (GD), p. 274-286, 2010. Slides

Michael Schneider

I am a research programmer for the University of Arizona. I am currently working on the NETVUE project

Recent Publications:

Melanie Hingle, Donella Yoon1, Joseph Fowler, Stephen Kobourov, Michael Lee Schneider, Daniel Falk and Randy Burd "Collection and visualization of dietary behavior and reasons for eating using a popular and free social media software application."