Wednesday, May 20, 2015

14:00 – 14:15 Opening
14:15 – 15:15 Keynote I by Osamu Saeki, Kyushu University
Chair: Hamish Carr
15:15 – 15:45 Coffee Break
15:45 – 17:25 Papers I (Scalar Fields)
Chair: Mario Hlawitschka

  • Persistence-based tracking of rainfall field maxima
    S. Biasotti, A. Cerri, S. Pittaluga, D. Sobrero, M. Spagnuolo
  • Topology-based Analysis for Multimodal Atmospheric Data of Volcano Eruptions
    A. Kuhn, W. Engelke, M. Flatken, F. Chen, H.-C. Hege, I. Hotz
  • Fast Similarity Search in Scalar Fields using Merging Histograms
    H. Saikia, H.-P. Seidel, T. Weinkauf
  • ADAPT – Adaptive Thresholds for Feature Extraction
    P.-T. Bremer
18:00 Dinner

Thursday, May 21, 2015

09:00 – 10:00 Keynote II by Kathrin Padberg-Gehle, Technische Universität Dresden
includes presentation of the paper

  • Transfer operator-based extraction of coherent features on surfaces
    K. Padberg-Gehle, S. Reuther, S. Praetorius, A. Voigt

Chair: Tino Weinkauf

10:00 – 10:30 Coffee Break
10:30 – 12:00 Papers II (Morse-Smale Complex)
Chair: Christian Heine

  • Piecewise Polynomial Reconstruction of Functions from Simplified Morse-Smale complex
    L. Allemand-Giorgis, G.-P. Bonneau, S. Hahmann
  • Morse-Smale Analysis of Ion Diffusion for DFT Battery Materials Simulations
    A. Gyulassy, A. Knoll, P.-T. Bremer, B. Wang, K. Chun Lau, M. E. Papka, V. Pascucci, L. Curtiss
  • Notes on the Distributed Computation of Merge Trees on CW-complexes
    A. Landge, P.-T. Bremer, A. Gyulassy, V. Pascucci
  • Efficient software for in-situ programmable visual analysis based on the Morse-Smale complex
    N. Shivashankar, V. Natarajan
12:00 – 13:30 Lunch
13:30 – 15:10 Papers III (Vector Field Topology)
Chair: Tino Weinkauf

  • On the Topological Extraction of Escape Maps
    R. Peikert, G. Machado, F. Sadlo
  • Finite Time Steady Vector Field Topology
    A. Friederici, C. Rössl, H. Theisel
  • Decomposition of Vector Fields Beyond Problems of First Order and Their Applications
    W. Reich, M. Hlawitschka, G. Scheuermann
  • Compute and Visualize Discontinuity Among Neighboring Integral Curves of 2D Vector Fields
    L. Zhang, R. Laramee, D. Thompson, A. Sescu, G. Chen
15:10 – 15:40 Coffee Break
15:40 – 17:20 Papers IV (High-Dimensional and Multivariate Analysis)
Chair: Christian Rössl

  • Visualizing Topological Properties of the Search Landscape of Combinatorial Optimization Problems
    S. Volke, D. Zeckzer, M. Middendorf, G. Scheuermann
  • Computing and Visualizing Time-Varying Merge Trees for High-Dimensional Data
    P. Oesterling, C. Heine, G. H. Weber, D. Morozov, G. Scheuermann
  • Analysing quality measures for dimensionality reduction using persistent homology
    B. Rieck, H. Leitte
  • Computing invariants of knotted graphs given by sequences of points in 3-dimensional space
    V. Kurlin
19:00 Dinner

Friday, May 22, 2015

09:00 – 10:15 Papers V (Coherent Structures)
Chair: Filip Sadlo

  • Hierarchical Watershed Ridges for Visualizing Lagrangian Coherent Structures
    M. Chen, J. C. Hart, S. C. Shadden
  • Computing Finite-Time Lyapunov Exponents in Approximated Vector Field
    S. Koch, S. Volke, M. Hlawitschka, G. Scheuermann, H. Hagen
  • Maximum Number of Degenerate Curves in 3D Linear Tensor Fields
    Y. Zhang, Y.-J. Tzeng, E. Zhang
10:15 – 10:45 Coffee Break
10:45 – 12:00 Papers VI (Multivariate Analysis)
Chair: Georges-Pierre Bonneau

  • A Comparison of Joint Contour Nets and Pareto SetsL. Huettenberger, C. Heine, C. Garth
  • Parallel and Distributed Computation of the Joint Contour Net
    F. Hosseini, D. Duke
  • Topological Analysis of Atlantic Ocean Data using Joint Contour Net
    Z. Geng, D. Duke, H. Carr
12:00 – 12:15 Closing Remarks
12:15 – 13:30 Lunch (optional)
13:30 – 18:00 Hike to Trifels Castle (optional)


Invited Keynotes

TopoInVis 2015 will feature two invited keynote talks:

Topology of Singular Fibers for Visualization

Osamu Saeki, Kyushu University
Slides of the keynote

Osamu Saeki is a keynote speaker at TopoInVis 2015

Osamu Saeki

Classical Morse theory studies a single function, or a scalar field, given on a space, and is indispensable for data visualization. In this talk, we consider an analogue for handling several functions at a time, or in other words, a multivariate function. We first introduce such a theory from a mathematical viewpoint, putting emphasis on the theoretical side. The key ingredient is the so-called “singular fiber”, which is a natural counterpart of a level set containing a critical point of a Morse function. As topological change of level sets occurs near critical points, topological change of pre-images is encoded in singular fibers. We will see that singular fibers help us to capture the global feature of a given set of multivariate data. Some algorithmic aspects are also presented in relation to joint contour nets. Many of the contents are a joint work with Shigeo Takahashi, Daisuke Sakurai, Hsiang-Yun Wu, Keisuke Kikuchi, Hamish Carr, David Duke, and Takahiro Yamamoto.

Professor Osamu Saeki got his PhD in Mathematics from the University of Tokyo in 1992, by his thesis on 4-dimensional topology. His main interest has been to investigate 3- and 4-dimensional geometric objects by using differential topology, and in particular, singularity theory of differentiable maps. He is known to be one of the pioneers who established the theory of singular fibers of such maps. He is now a professor at the Institute of Mathematics for Industry, Kyushu University, and his recent main interest includes collaboration with computer scientists for enhancing visualization of multivariate data.

Transfer-Operator Methods for Analyzing Flow Data

Kathrin Padberg-Gehle, Technische Universität Dresden

Kathrin Padberg-Gehle is a keynote speaker at TopoInVis 2015

Kathrin Padberg-Gehle

In this talk we discuss the theory and application of transfer-operator based methods for the numerical analysis of complex flows. Transfer operators describe the evolution of densities under the action of the flow. They can be efficiently approximated within a set-oriented numerical framework and spectral properties of the resulting stochastic matrices are used to extract finite-time coherent sets. Also finite-time entropy, a density-based stretching quantity similar to finite-time Lyapunov exponents, is conveniently approximated by means of the discretized transfer operator. Transfer operator-based computational methods are purely probabilistic and derivative-free. Therefore they can also be applied in settings where derivatives of the flow map are hardly accessible. We demonstrate our approach in a number of example systems, in particular in the context of geophysical flow data.

Jun.-Prof. Dr. Kathrin Padberg-Gehle obtained her PhD in Mathematics at the University of Paderborn (UPB), Germany, in 2005. She was a postdoctoral researcher in the DFG research training group “Scientific Computation” at UPB from 2005 to 2007 and at the Institute of Transport and Economics at Technische Universität Dresden (TUD), Germany, from 2007 to 2010. From 2008 to 2010 she was a visiting scientist at TUD’s Center for Information Services and High Performance Computing. Since 2010 she has been assistant professor for Applied Mathematics at the Institute for Scientific Computing at TUD. Dr. Padberg-Gehle’s research focuses on the development of set-oriented methods for the numerical analysis of transport and mixing in complex systems and their applications in fluid dynamics.