@misc{ReininghausKastenWeinkaufetal., author = {Reininghaus, Jan and Kasten, Jens and Weinkauf, Tino and Hotz, Ingrid}, title = {Combinatorial Feature Flow Fields: Tracking Critical Points in Discrete Scalar Fields}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-12151}, number = {11-02}, abstract = {We propose a combinatorial algorithm to track critical points of 2D time-dependent scalar fields. Existing tracking algorithms such as Feature Flow Fields apply numerical schemes utilizing derivatives of the data, which makes them prone to noise and involve a large number of computational parameters. In contrast, our method is robust against noise since it does not require derivatives, interpolation, and numerical integration. Furthermore, we propose an importance measure that combines the spatial persistence of a critical point with its temporal evolution. This leads to a time-aware feature hierarchy, which allows us to discriminate important from spurious features. Our method requires only a single, easy-to-tune computational parameter and is naturally formulated in an out-of-core fashion, which enables the analysis of large data sets. We apply our method to a number of data sets and compare it to the stabilized continuous Feature Flow Field tracking algorithm.}, language = {en} } @article{HegeKastenHotz2011, author = {Hege, Hans-Christian and Kasten, Jens and Hotz, Ingrid}, title = {Distillation and Visualization of Spatiotemporal Structures in Turbulent Flow Fields}, series = {J. Phys.}, volume = {318}, journal = {J. Phys.}, edition = {6}, doi = {10.1088/1742-6596/318/6/062009}, pages = {062009}, year = {2011}, language = {en} } @phdthesis{Kasten2012, author = {Kasten, Jens}, title = {Lagrangian feature extraction in two-dimensional unsteady flows}, year = {2012}, language = {en} } @article{KastenReininghausHotzetal.2011, author = {Kasten, Jens and Reininghaus, Jan and Hotz, Ingrid and Hege, Hans-Christian}, title = {Two-Dimensional Time-Dependent Vortex Regions Based on the Acceleration Magnitude}, series = {IEEE Transactions on Visualization and Computer Graphics}, volume = {17}, journal = {IEEE Transactions on Visualization and Computer Graphics}, number = {12}, pages = {2080 -- 2087target}, year = {2011}, language = {en} } @article{ReininghausKotavaGuentheretal.2011, author = {Reininghaus, Jan and Kotava, N. and G{\"u}nther, David and Kasten, Jens and Hagen, Hans and Hotz, Ingrid}, title = {A Scale Space Based Persistence Measure for Critical Points in 2D Scalar Fields}, series = {Visualization and Computer Graphics, IEEE Transactions on}, volume = {17}, journal = {Visualization and Computer Graphics, IEEE Transactions on}, number = {12}, doi = {10.1109/TVCG.2011.159}, pages = {2045 -- 2052}, year = {2011}, language = {en} } @article{LacarellePMoeckPaschereitetal.2010, author = {Lacarelle, Arnaud and P. Moeck, Jonas and Paschereit, Christian and Gelbert, Gregor and King, Rudibert and M. Luchtenburg, Dirk and Noack, Bernd R. and Kasten, Jens and Hege, Hans-Christian}, title = {Modeling a Fuel/Air Mixing to Control the Pressure Pulsations and NOx Emissions in a Lean Premixed Combustor}, series = {Active Flow Control II}, volume = {108}, journal = {Active Flow Control II}, publisher = {Springer, Berlin}, doi = {10.1007/978-3-642-11735-0_20}, pages = {307 -- 321}, year = {2010}, language = {en} } @incollection{KastenWeinkaufPetzetal.2010, author = {Kasten, Jens and Weinkauf, Tino and Petz, Christoph and Hotz, Ingrid and Noack, Bernd R. and Hege, Hans-Christian}, title = {Extraction of Coherent Structures from Natural and Actuated Flows}, series = {Active Flow Control II}, volume = {108}, booktitle = {Active Flow Control II}, publisher = {Springer, Berlin}, isbn = {978-3-642-11734-3}, doi = {10.1007/978-3-642-11735-0_24}, pages = {373 -- 387}, year = {2010}, language = {en} } @inproceedings{KochWiebelKastenetal.2013, author = {Koch, Stefan and Wiebel, Alexander and Kasten, Jens and Hlawitschka, Mario}, title = {Visualizing Linear Neighborhoods in Non-Linear Vector Fields}, series = {Proceedings of the IEEE Pacific Visualization Symposium}, booktitle = {Proceedings of the IEEE Pacific Visualization Symposium}, address = {Sydney, Australia}, pages = {249 -- 256}, year = {2013}, language = {en} } @inproceedings{AuerKastenKratzetal.2013, author = {Auer, Cornelia and Kasten, Jens and Kratz, Andrea and Zhang, Eugene and Hotz, Ingrid}, title = {Automatic, Tensor-Guided Illustrative Vector Field Visualization}, series = {Proc. IEEE Pacific Visualization Symposium 2013}, booktitle = {Proc. IEEE Pacific Visualization Symposium 2013}, address = {Sydney, Australia}, doi = {10.1109/PacificVis.2013.6596154}, pages = {265 -- 275}, year = {2013}, language = {en} } @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} }