@article{KastenReininghausHotzetal.2016, author = {Kasten, Jens and Reininghaus, Jan and Hotz, Ingrid and Hege, Hans-Christian and Noack, Bernd and Daviller, Guillaume and Morzyński, Marek}, title = {Acceleration feature points of unsteady shear flows}, series = {Archives of Mechanics}, volume = {68}, journal = {Archives of Mechanics}, number = {1}, pages = {55 -- 80}, year = {2016}, abstract = {A framework is proposed for extracting features in 2D transient flows, based on the acceleration field to ensure Galilean invariance. The minima of the acceleration magnitude, i.e. a superset of the acceleration zeros, are extracted and discriminated into vortices and saddle points --- based on the spectral properties of the velocity Jacobian. The extraction of topological features is performed with purely combinatorial algorithms from discrete computational topology. The feature points are prioritized with persistence, as a physically meaningful importance measure. These features are tracked in time with a robust algorithm for tracking features. Thus a space-time hierarchy of the minima is built and vortex merging events are detected. The acceleration feature extraction strategy is applied to three two-dimensional shear flows: (1) an incompressible periodic cylinder wake, (2) an incompressible planar mixing layer and (3) a weakly compressible planar jet. The vortex-like acceleration feature points are shown to be well aligned with acceleration zeros, maxima of the vorticity magnitude, minima of pressure field and minima of λ2.}, language = {en} } @inproceedings{KuhnEngelkeFlatkenetal., author = {Kuhn, Alexander and Engelke, Wito and Flatken, Markus and Hege, Hans-Christian and Hotz, Ingrid}, title = {Topology-based Analysis for Multimodal Atmospheric Data of Volcano Eruptions}, series = {Topological Methods in Data Analysis and Visualization IV}, booktitle = {Topological Methods in Data Analysis and Visualization IV}, publisher = {Springer}, address = {Cham, Schweiz}, doi = {10.1007/978-3-319-44684-4_2}, pages = {35 -- 50}, language = {en} } @incollection{HlawitschkaHotzKratzetal.2014, author = {Hlawitschka, Mario and Hotz, Ingrid and Kratz, Andrea and Marai, G. Elisabeta and Moreno, Rodrigo and Scheuermann, Gerik and Stommel, Markus and Wiebel, Alexander and Zhang, Eugene}, title = {Top Challenges in the Visualization of Engineering Tensor Fields}, series = {Visualization and Processing of Tensors and Higher-Order Descriptors for Multi-Field Data}, booktitle = {Visualization and Processing of Tensors and Higher-Order Descriptors for Multi-Field Data}, editor = {Westin, Carl-Frederic and Burgeth, Bernhard and Vilanova, Anna}, publisher = {Springer}, pages = {3 -- 15}, year = {2014}, language = {en} } @misc{KastenReininghausHotzetal., author = {Kasten, Jens and Reininghaus, Jan and Hotz, Ingrid and Hege, Hans-Christian and Noack, Bernd and Daviller, Guillaume and Morzyński, Marek}, title = {Acceleration feature points of unsteady shear flows}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-58397}, abstract = {A framework is proposed for extracting features in 2D transient flows, based on the acceleration field to ensure Galilean invariance. The minima of the acceleration magnitude, i.e. a superset of the acceleration zeros, are extracted and discriminated into vortices and saddle points --- based on the spectral properties of the velocity Jacobian. The extraction of topological features is performed with purely combinatorial algorithms from discrete computational topology. The feature points are prioritized with persistence, as a physically meaningful importance measure. These features are tracked in time with a robust algorithm for tracking features. Thus a space-time hierarchy of the minima is built and vortex merging events are detected. The acceleration feature extraction strategy is applied to three two-dimensional shear flows: (1) an incompressible periodic cylinder wake, (2) an incompressible planar mixing layer and (3) a weakly compressible planar jet. The vortex-like acceleration feature points are shown to be well aligned with acceleration zeros, maxima of the vorticity magnitude, minima of pressure field and minima of λ2.}, language = {en} } @misc{KastenHotzHege, author = {Kasten, Jens and Hotz, Ingrid and Hege, Hans-Christian}, title = {On the Elusive Concept of Lagrangian Coherent Structures}, series = {Topological Methods in Data Analysis and Visualization II}, journal = {Topological Methods in Data Analysis and Visualization II}, editor = {Peikert, Ronald and Hauser, Helwig and Carr, Hamish and Fuchs, Raphael}, publisher = {Springer}, doi = {10.1007/978-3-642-23175-9_14}, pages = {207 -- 220}, language = {en} } @article{ZobelReininghausHotz2011, author = {Zobel, Valentin and Reininghaus, Jan and Hotz, Ingrid}, title = {Generalized Heat Kernel Signature}, series = {Journal of WSCG, International Conference on Computer Graphics, Visualization and Computer Vision}, journal = {Journal of WSCG, International Conference on Computer Graphics, Visualization and Computer Vision}, pages = {93 -- 100target}, year = {2011}, language = {en} } @misc{KastenReininghausOberleithneretal.2010, author = {Kasten, Jens and Reininghaus, Jan and Oberleithner, Kilian and Hotz, Ingrid and Noack, Bernd and Hege, Hans-Christian}, title = {Flow over a Cavity - Evolution of the Vortex Skeleton}, publisher = {Visualization at 28th Annual Gallery of Fluid Motion exhibit, held at the 63th Annual Meeting of the American Physical Society, Division of Fluid Dynamics (Long Beach, CA, USA, November 21-23, 2010).}, year = {2010}, language = {en} } @article{KastenPetzHotzetal.2010, author = {Kasten, Jens and Petz, Christoph and Hotz, Ingrid and Hege, Hans-Christian and Noack, Bernd and Tadmor, Gilead}, title = {Lagrangian Feature Extraction of the Cylinder Wake}, series = {Physics of Fluids}, volume = {22}, journal = {Physics of Fluids}, number = {9}, doi = {10.1063/1.3483220}, pages = {091108}, year = {2010}, language = {en} } @inproceedings{KratzKettlitzHotz2011, author = {Kratz, Andrea and Kettlitz, Nino and Hotz, Ingrid}, title = {Particle-Based Anisotropic Sampling for Two-Dimensional Tensor Field Visualization}, series = {Vision Modeling and Visualization (VMV'11)}, booktitle = {Vision Modeling and Visualization (VMV'11)}, publisher = {Eurographics Association target}, pages = {145 -- 152}, year = {2011}, language = {en} } @misc{KratzMeyerHotz2011, author = {Kratz, Andrea and Meyer, Bj{\"o}rn and Hotz, Ingrid}, title = {A Visual Approach to Analysis of Stress Tensor Fields}, series = {Scientific Visualization: Interactions, Features, Metaphors}, volume = {2}, journal = {Scientific Visualization: Interactions, Features, Metaphors}, editor = {Hagen, Hans}, publisher = {Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik}, address = {Dagstuhl, Germany}, doi = {10.4230/DFU.Vol2.SciViz.2011.188}, pages = {188 -- 211}, year = {2011}, language = {en} }