The VISualization & graphIX (VISIX) group led byProf. Dr.-Ing. Lars Linsenis concerned with the development of interactive visual representations and analysis systems. Today, digital data are acquired with an increasing amount in all fields of science and technology. Visualization methods allow for the extraction of relevant information from these sets of data and to display this information in an effective and intuitive way for human beings. Interaction mechanisms are employed to filter and refine the displays within a visual analysis process. VISIX develops visualization approaches for application in medicine, life sciences, physics, and geosciences, among others.
News
Informatiker analysieren die Ausbreitung von Waldbränden
Wissenschaftler und Studierende arbeiten gemeinsam an praxisnahen Lösungen
Trockenheit und extrem hohe Temperaturen hatten dieses Jahr ganz Europa fest im Griff. Im Sommer 2022 zerstörten Feuer mehr europäischen Wald – insgesamt 660.000 Hektar – als je in einem Sommer seit Beginn der Aufzeichnungen. Am schlimmsten betroffen war in diesem Jahr Spanien mit 245.000 Hektar verbrannter Fläche – es folgen Rumänien mit 150.000 und Portugal mit 75.000 Hektar. In Deutschland vernichteten Großbrände bis November mehr als 4.300 Hektar Waldfläche, ein Vielfaches von dem, was zwischen 2006 und 2021 im Durchschnitt pro Jahr verbrannt ist. Ein wichtiges Thema, mit dem sich die Arbeitsgruppe von Prof. Dr. Lars Linsen vom Institut für Informatik der WWU im Rahmen eines Projektseminars beschäftigte. Seine Studierenden durften an einem internationalen wissenschaftlichen Wettbewerb mitwirken und wurden frühzeitig an aktuelle Forschungsfragen herangeführt. Und das mit großem Erfolg: Das Team erzielte den ersten Platz.
Der „SciVis Contest“ beschäftigt sich mit Datenanalyseproblemen aus den Naturwissenschaften oder der Medizin. Der Wettbewerb ruft jedes Jahr Forschungsteams aus der ganzen Welt zum Mitmachen auf. Die diesjährige Aufgabe bestand in der visuellen Analyse von Waldbrandsimulationen. „Gemeinsam mit Doktoranden und Studierenden entwickelten wir über mehrere Monate interaktive visuelle Methoden, um ein Problem zu lösen und praxisnahe Hilfestellungen für die Feuerwehr und Behörden abzuleiten“, erklärt Lars Linsen, der seit 2017 die Arbeitsgruppe „Visualization and Graphics“ leitet.
Für die Untersuchung, wie Waldbrände sich ausbreiten, ist das Verständnis der Wechselwirkungen verschiedener physikalischer und chemischer Phänomene entscheidend. Der Untergrund und die Vegetation der Umgebung, die Windrichtung oder die Topografie spielen hierbei eine bedeutende Rolle. „Unsere Arbeit konzentrierte sich auf die Analyse der Strömungseigenschaften, insbesondere der Windturbulenzen“, erläutert Lars Linsen das Vorgehen. „Das trägt dazu bei, den Einfluss der Geländeform auf die Brandausbreitung zu verstehen.“ Das Team erstellte mehrere Übersichtsgrafiken, die unter anderem die Ausbreitung des Feuers über die Zeit zeigen und dadurch einen Vergleich zwischen verschiedenen Simulationsläufen ermöglichen. So fanden die Studierenden heraus, dass die seitliche Ausbreitung des Feuers bei steileren Bergen größer ist als bei flacheren Hängen. Ein weiteres Ergebnis der Analyse war die Rolle von Bergkuppen: Wenn sich das Feuer in Windrichtung vor der Bergkuppe entzündet hat, breitet es sich demzufolge über die Bergkuppe hinweg aus. Das sei nicht der Fall, wenn sich das Feuer hinter einer Bergkuppe entzündet. Diese Erkenntnisse sollen der Feuerwehr und den zuständigen Behörden helfen, Gefahren und die künftige Ausbreitung von Waldbränden besser einzuschätzen.
Die Doktorandin Marina Evers präsentierte die Ergebnisse Ende Oktober auf der internationalen Konferenz IEEE VIS in Oklahoma City in den USA. Sie nahm stellvertretend für das Team den ersten Preis entgegen. „An etwas zu arbeiten, das sowohl Menschen als auch die Natur schützen kann, hat uns alle sehr motiviert. Dass unsere Arbeit nun zum Gewinnerprojekt auserkoren wurde, freut uns natürlich besonders“, betont sie. Nach 2018, als es um eine Analyse von Asteroideneinschlägen in der Tiefsee ging, und 2020 zum Thema Meeresströmungen im Roten Meer hat das Team um Lars Linsen nun zum dritten Mal beim „SciVis Contest“ den ersten Platz erreicht.
Autorin: Kathrin Kottke
Dieser Artikel stammt aus der Unizeitung wissen|leben Nr. 8, 21. Dezember 2022: Link
VCBM conference paper on Radiofrequency Ablation Simulation Analysis
Prof. Lars Linsen presented a joint conference paper with Karl Heimes and Marina Evers, as well as Tim Gerrits (RWTH Aachen) and Sandeep Gyawali, David Sinden and Tobias Preusser (Fraunhofer MEVIS, Bremen) on "Studying the effect of tissue properties on radiofrequency ablation by visual simulation ensemble analysis" (Link) at the 12th Eurographics workshop on Visual Computing in Biology and Medicine (VCBM 2022), which took place in Vienna, Austria, on September 22-23, 2022. The paper received an Honorable Mention Full Paper Award.
Marina Evers and Prof. Lars Linsen published a paper on Multi-dimensional parameter-space partitioning of spatio-temporal simulation ensembles (Link) in the Elsevier journal on Computers & Graphics (Link).
New DFG project on "Visual Analysis of Hemodynamics Simulations for Increased Spatio-temporal PC-MRI Resolution"
We have acquired a new DFG-funded project (project number: 468824876, LI 1530/28-1) on "Visual Analysis of Hemodynamics Simulations for Increased Spatio-temporal PC-MRI Resolution". This project is a collaboration with the group of Dr. Mathias Krause (KIT) and Prof. Dr. Verena Hörr (University of Bonn and WWU) and will run for 3 years.
VCBM conference paper on Measured and Simulated Tubular Flow Analysis
Quynh Quang Ngo successfully defended his PhD thesis in Computer Science at the WWU under supervision of Prof. Lars Linsen on Visual Similarity Analysis for Dynamic Systems. Congratulations!
Muhammad Jawad successfully defended his PhD thesis in Computer Science at the WWU under supervision of Prof. Lars Linsen on Interactive Visual Analysis of Spectroscopy Imaging Data. Congratulations!
Ali Sheharyar successfully defended his PhD thesis in Computer Science at the WWU under supervision of Prof. Lars Linsen on Visual Analysis of Regional Myocardial Motion Data. Congratulations!
Dr. Vladimir Molchanov presented a joint conference paper with Prof. Lars Linsen on Smooth Map Deformation Using Integral Images at the 28. International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision 2020 (WSCG 2020), held virtually on June 19-21, 2020.
Bojan Kocev successfully defended his PhD thesis in Computer Science at Jacobs University under co-supervision of Prof. Lars Linsen on Modeling, Estimating, and Visualizing Spatial and Temporal Uncertainty for Image-guided Therapy. Congratulations!
José Matute successfully defended his PhD thesis in Computer Science at the WWU under supervision of Prof. Lars Linsen on Visual Analysis of Heterogeneous Medical Data for Cohort Studies. Congratulations!
Prof. Linsen presents visualization tool in TV documentary
The German TV channel ARD broadcasted a history documentary on the robbery of children by the Nazis (German title: Kinderraub der Nazis - Die vergessenen Opfer). In the documentary, Prof. Linsen presented a visualization tool developed together with José Matute, which was applied to data acquired by a colleague from History Prof. Isabel Heinemann.
Our team assistant Evelyn Egelkamp retires today. We are very sorry to lose her, but, at the same time, are very grateful that she has been with us and supported our group for more than 3 years. In fact, Evelyn Egelkamp supported the Institute of Computer Science for several decades as a team assistant. We appreciate all the dedication and skills she put into her work. We wish Evelyn Egelkamp a pleasant and joyful retirement. It is well deserved.
IVAPP conference paper on Billiard Dynamics Ensemble Analysis
Quanh Quang Ngo presented a joint conference paper with Stefan Boshe-Plois and Prof. Lars Linsen as well as Prof. Peter Albers (University of Heidelberg) on Visual Analysis of Billiard Dynamics Simulation Ensembles at the International Conference on Information Visualization Theory and Applications (IVAPP 2020), held in Valetta, Malta, on February 27-29, 2020.
IVAPP conference paper on Time-varying Topological Landscapes
Maria Herick presented a joint conference paper with Dr. Vladimir Molchanov and Prof. Lars Linsen on Temporally Coherent Topological Landscapes for Time-varying Scalar Fields at the International Conference on Information Visualization Theory and Applications (IVAPP 2020), held in Valetta, Malta, on February 27-29, 2020.
Prof. Linsen was re-elected by the general assembly to serve a second two-year period in the management board of the Center for Digital Humanties (CDH) of the WWU Münster. Subsequently, he was also re-elected by the management board to serve as its deputy speaker of the.
Prof. Linsen has been invited to contribute as a panelist to the 7th Viadrina Compliance Congress on November 13-14, 2019, in Berlin. The topic of the panel was AI-Compliance, i.e., how Artificial Intelligence may help or hinder the Compliance process.
Invited paper talk on Uncertainty in Medical Visualization at VCBM 2019
Prof. Lars Linsen presented a paper on Uncertainty Visualization for Interactive Assessment of Stenotic Regions in Vascular Structures at the 9th Eurographics workshop on Visual Computing in Biology and Medicine (VCBM 2019), which took place September 4-6, 2019, in Brno, Czech Republic. This was an invirted paper talk of a Computers & Graphics publication. Co-authors are Dr. Gordan Ristovski, José Matute, Prof. Horst Hahn (Fraunhofer MEVIS), Dr. Thomas Wehrum (University Hospital Freiburg), and Prof. Andreas Harloff (University Hospital Freiburg).
Prof. Lars Linsen served as one of the three paper chairs of the 9th Eurographics workshop on Visual Computing in Biology and Medicine (VCBM 2019), which took place September 4-6, 2019, in Brno, Czech Republic. He also chaired a session and served as a judge in the image contest.
Springer book chapter on MR Spectroscopy Data Visualization
Muhammad Jawad, Marina Evers, Alexander Gerwing, Maria Herick, Daniel Seibert, and Prof. Lars Linsen published a paper on A Visual Analytics Approach for Comparing Cohorts in Single-Voxel Magnetic Resonance Spectroscopy Data in the edited Springer book on Biomedical Visualization (Vol. 2) within the series on Advances in Experimental Medicine and Biology with Prof. Patricia Ohrmann from the Department of Psychiatry and Psychiotherapy of the University of Münster as well as Dr. Jochen Bauer and Dr. Harald Kugel from Institute of Clinical Radiology of the University Hospital Münster.
Prof. Linsen co-chair of EuroVis workshop on TrustVis
Prof. Lars Linsen co-chaired this year's EuroVis workshop on TrustVis, held on June 3, 2019, in Porto, Portugal, with Dr. Robert Kosara (Tableau Software, USA), Kai Lawonn (University of Koblenz-Landau, Germany), and Noeska Smits (University of Bergen, Norway).
TrustVis workshop paper on Uncertainty Visualization
At IEEE VIS 2018, Simon Leistikow, Karim Huesmann, and Prof. Lars Linsen (left to right) received the award for the winning entry of the SciVis contest. Dr. Alexey Fofonov was also co-author.
This year the VISIX group had record attendance at the IEEE VIS 2018 conference in Berlin, Germany, with 9 participants. For the picture, former group member Prof. Paul Rosenthal joined, as well.
Dr. Vladimir Molchanov and Prof. Lars Linsen present a paper at the IEEE VIS 2018 conference held in Berlin on October 21-26. The paper on "Shape-preserving Star Coordinates" will appear in a special issue of the IEEE Transaction of Visualization and Computer Graphics (TVCG).
Demo at ACM SUI 2018
Karim Huesmann, Dr. Dimitar Valkov, and Prof. Lars Linsen present a demo at the 6th ACM Symposium on Spatial User Interaction (ACM SUI 2018) in Berlin, October 13-14, 2018, on "RealityAlert: Improving Users' Physical Safety in Immersive Virtual Environments"
New DFG Project on "Visual Analysis of Multi-run Multi-field Simulation Data"
Prof. Linsen has acquired a new 3-years DFG project LI 1530/21-2 on "Visual Analysis of Multi-run Multi-field Simulation Data", which is a continuation of the DFG project LI 1530/21-1. The position is to be filled and there will be a respective job ad being out soon.
