@inproceedings{BeckHegeSeebassetal.1996, author = {Beck, Rudolf and Hege, Hans-Christian and Seebaß, Martin and Wust, Peter and Deuflhard, Peter and Felix, Roland}, title = {Adaptive Finite Element Codes for Numerical Calculations in Hyperthermia Treatment Planning}, series = {Proceedings of the 17th Congress on Hyperthermic Oncology}, volume = {2}, booktitle = {Proceedings of the 17th Congress on Hyperthermic Oncology}, address = {Rome, Italy}, pages = {515 -- 517}, year = {1996}, 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} } @article{LindowBaumProhaskaetal.2010, author = {Lindow, Norbert and Baum, Daniel and Prohaska, Steffen and Hege, Hans-Christian}, title = {Accelerated Visualization of Dynamic Molecular Surfaces}, series = {Comput. Graph. Forum}, volume = {29}, journal = {Comput. Graph. Forum}, doi = {10.1111/j.1467-8659.2009.01693.x}, pages = {943 -- 952}, year = {2010}, language = {en} } @article{FroehlerElberfeldMoelleretal., author = {Fr{\"o}hler, Bernhard and Elberfeld, Tim and M{\"o}ller, Torsten and Hege, Hans-Christian and Weissenb{\"o}ck, Johannes and De Beenhouwer, Jan and Sijbers, Jan and Kastner, Johann and Heinzl, Christoph}, title = {A Visual Tool for the Analysis of Algorithms for Tomographic Fiber Reconstruction in Materials Science}, series = {Computer Graphics Forum}, volume = {38}, journal = {Computer Graphics Forum}, number = {3}, doi = {10.1111/cgf.13688}, pages = {273 -- 283}, abstract = {We present visual analysis methods for the evaluation of tomographic fiber reconstruction algorithms by means of analysis, visual debugging and comparison of reconstructed fibers in materials science. The methods are integrated in a tool (FIAKER) that supports the entire workflow. It enables the analysis of various fiber reconstruction algorithms, of differently parameterized fiber reconstruction algorithms and of individual steps in iterative fiber reconstruction algorithms. Insight into the performance of fiber reconstruction algorithms is obtained by a list-based ranking interface. A 3D view offers interactive visualization techniques to gain deeper insight, e.g., into the aggregated quality of the examined fiber reconstruction algorithms and parameterizations. The tool was designed in close collaboration with researchers who work with fiber-reinforced polymers on a daily basis and develop algorithms for tomographic reconstruction and characterization of such materials. We evaluate the tool using synthetic datasets as well as tomograms of real materials. Five case studies certify the usefulness of the tool, showing that it significantly accelerates the analysis and provides valuable insights that make it possible to improve the fiber reconstruction algorithms. The main contribution of the paper is the well-considered combination of methods and their seamless integration into a visual tool that supports the entire workflow. Further findings result from the analysis of (dis-)similarity measures for fibers as well as from the discussion of design decisions. It is also shown that the generality of the analytical methods allows a wider range of applications, such as the application in pore space analysis.}, language = {en} } @article{VohraHarthIsoeetal., author = {Vohra, Sumit Kumar and Harth, Philipp and Isoe, Yasuko and Bahl, Armin and Fotowat, Haleh and Engert, Florian and Hege, Hans-Christian and Baum, Daniel}, title = {A Visual Interface for Exploring Hypotheses about Neural Circuits}, series = {IEEE Transactions on Visualization and Computer Graphics}, journal = {IEEE Transactions on Visualization and Computer Graphics}, doi = {10.1109/TVCG.2023.3243668}, abstract = {One of the fundamental problems in neurobiological research is to understand how neural circuits generate behaviors in response to sensory stimuli. Elucidating such neural circuits requires anatomical and functional information about the neurons that are active during the processing of the sensory information and generation of the respective response, as well as an identification of the connections between these neurons. With modern imaging techniques, both morphological properties of individual neurons as well as functional information related to sensory processing, information integration and behavior can be obtained. Given the resulting information, neurobiologists are faced with the task of identifying the anatomical structures down to individual neurons that are linked to the studied behavior and the processing of the respective sensory stimuli. Here, we present a novel interactive tool that assists neurobiologists in the aforementioned task by allowing them to extract hypothetical neural circuits constrained by anatomical and functional data. Our approach is based on two types of structural data: brain regions that are anatomically or functionally defined, and morphologies of individual neurons. Both types of structural data are interlinked and augmented with additional information. The presented tool allows the expert user to identify neurons using Boolean queries. The interactive formulation of these queries is supported by linked views, using, among other things, two novel 2D abstractions of neural circuits. The approach was validated in two case studies investigating the neural basis of vision-based behavioral responses in zebrafish larvae. Despite this particular application, we believe that the presented tool will be of general interest for exploring hypotheses about neural circuits in other species, genera and taxa.}, language = {en} } @article{SipsKothurUngeretal.2012, author = {Sips, Mike and Kothur, Patrick and Unger, Andrea and Hege, Hans-Christian and Dransch, Doris}, title = {A Visual Analytics Approach to Multiscale Exploration of Environmental Time Series}, series = {IEEE Transactions on Visualization and Computer Graphics}, volume = {18}, journal = {IEEE Transactions on Visualization and Computer Graphics}, number = {12}, doi = {10.1109/TVCG.2012.191}, pages = {2899 -- 2907}, year = {2012}, abstract = {We present a Visual Analytics approach that addresses the detection of interesting patterns in numerical time series, specifically from environmental sciences. Crucial for the detection of interesting temporal patterns are the time scale and the starting points one is looking at. Our approach makes no assumption about time scale and starting position of temporal patterns and consists of three main steps: an algorithm to compute statistical values for all possible time scales and starting positions of intervals, visual identification of potentially interesting patterns in a matrix visualization, and interactive exploration of detected patterns. We demonstrate the utility of this approach in two scientific scenarios and explain how it allowed scientists to gain new insight into the dynamics of environmental systems.}, language = {en} } @inproceedings{ProhaskaHegeGiehletal.2003, author = {Prohaska, Steffen and Hege, Hans-Christian and Giehl, Michael and Gowin, Wolfgang}, title = {A Virtual Laboratory for Assessment of Bone Biopsies}, series = {14th IAA Humans in Space Symposium}, booktitle = {14th IAA Humans in Space Symposium}, address = {Banff, Alberta, Canada}, pages = {7}, year = {2003}, language = {en} } @inproceedings{WeinkaufSahnerTheiseletal.2007, author = {Weinkauf, Tino and Sahner, Jan and Theisel, Holger and Hege, Hans-Christian and Seidel, Hans-Peter}, title = {A unified feature extraction architecture}, series = {Active Flow Control}, booktitle = {Active Flow Control}, publisher = {Springer Berlin/Heidelberg}, doi = {10.1007/978-3-540-71439-2_8}, pages = {119 -- 133}, year = {2007}, language = {en} } @article{BrandtRohlfingRybaketal.2005, author = {Brandt, Robert and Rohlfing, Torsten and Rybak, J{\"u}rgen and Krofczik, Sabine and Maye, Alexander and Westerhoff, Malte and Hege, Hans-Christian and Menzel, Randolf}, title = {A three-dimensional average-shape atlas of the honeybee brain and its applications}, series = {Journal of Comparative Neurology}, volume = {492(1)}, journal = {Journal of Comparative Neurology}, pages = {1 -- 19}, year = {2005}, language = {en} } @article{UdvaryHarthMackeetal., author = {Udvary, Daniel and Harth, Philipp and Macke, Jakob H. and Hege, Hans-Christian and de Kock, Christiaan P. J. and Sakmann, Bert and Oberlaender, Marcel}, title = {A Theory for the Emergence of Neocortical Network Architecture}, series = {BioRxiv}, journal = {BioRxiv}, doi = {https://doi.org/10.1101/2020.11.13.381087}, language = {en} } @incollection{KadookaOnishiChoietal.2003, author = {Kadooka, Yoshimasa and Onishi, Naoki and Choi, Jang-Woon and Lee, Young-Ho and Hege, Hans-Christian and Tago, Yoshio}, title = {A Study on the PIV Virtual Laboratory by Web Grid Technology}, series = {CD ROM Proc. PIV'03 - 5th Int. Symp. on Particle Image Velocimetry}, booktitle = {CD ROM Proc. PIV'03 - 5th Int. Symp. on Particle Image Velocimetry}, editor = {Kim, Kyung}, publisher = {The Korean Society of Visualization}, address = {Busan, Korea}, year = {2003}, language = {en} } @inproceedings{HarthVohraUdvaryetal., author = {Harth, Philipp and Vohra, Sumit and Udvary, Daniel and Oberlaender, Marcel and Hege, Hans-Christian and Baum, Daniel}, title = {A Stratification Matrix Viewer for Analysis of Neural Network Data}, series = {Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM)}, booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM)}, address = {Vienna, Austria}, doi = {10.2312/vcbm.20221194}, abstract = {The analysis of brain networks is central to neurobiological research. In this context the following tasks often arise: (1) understand the cellular composition of a reconstructed neural tissue volume to determine the nodes of the brain network; (2) quantify connectivity features statistically; and (3) compare these to predictions of mathematical models. We present a framework for interactive, visually supported accomplishment of these tasks. Its central component, the stratification matrix viewer, allows users to visualize the distribution of cellular and/or connectional properties of neurons at different levels of aggregation. We demonstrate its use in four case studies analyzing neural network data from the rat barrel cortex and human temporal cortex.}, language = {en} } @inproceedings{CoconuUllmerPaaretal.2018, author = {Coconu, Liviu and Ullmer, Brygg and Paar, Philip and Liu, Jing and Konkel, Miriam and Hege, Hans-Christian}, title = {A smartphone-based tangible interaction approach for landscape visualization.}, series = {PerDis '18 Proceedings of the 7th ACM International Symposium on Pervasive Displays, Munich, Germany, June 6-8, 2018}, booktitle = {PerDis '18 Proceedings of the 7th ACM International Symposium on Pervasive Displays, Munich, Germany, June 6-8, 2018}, publisher = {ACM}, address = {New York, NY, USA}, doi = {10.1145/3205873.3210707}, pages = {no. 23}, year = {2018}, abstract = {The use of tangible interfaces for navigation of landscape scenery - for example, lost places re-created in 3D - has been pursued and articulated as a promising, impactful application of interactive visualization. In this demonstration, we present a modern, low-cost implementation of a previously-realized multimodal gallery installation. Our demonstration centers upon the versatile usage of a smartphone for sensing, navigating, and (optionally) displaying element on a physical surface in tandem with a larger, more immersive display.}, language = {en} } @inproceedings{NadobnyWustStallingetal.1997, author = {Nadobny, Jacek and Wust, Peter and Stalling, Detlev and Hege, Hans-Christian and Deuflhard, Peter and Felix, Roland}, title = {A Quantitative Comparison Between VSIE and the FDTD Method Using Electrically Equivalent Patient and Antenna Models}, series = {Proceedings of 16th Annual Meeting of the European Society for Hyperthermic Oncology ESHO-97}, booktitle = {Proceedings of 16th Annual Meeting of the European Society for Hyperthermic Oncology ESHO-97}, address = {Berlin, Germany}, pages = {145}, year = {1997}, language = {en} } @inproceedings{BaumHege2006, author = {Baum, Daniel and Hege, Hans-Christian}, title = {A Point-matching based algorithm for 3D surface alignment of drug-sized molecules}, series = {Computational Life Sciences II, Second International Symposium, CompLife 2006, Cambridge (UK), Sept. 2006}, volume = {4216}, booktitle = {Computational Life Sciences II, Second International Symposium, CompLife 2006, Cambridge (UK), Sept. 2006}, publisher = {Springer}, doi = {10.1007/11875741_18}, pages = {183 -- 193}, year = {2006}, language = {en} } @inproceedings{HanikHegevonTycowicz, author = {Hanik, Martin and Hege, Hans-Christian and von Tycowicz, Christoph}, title = {A Nonlinear Hierarchical Model for Longitudinal Data on Manifolds}, series = {2022 IEEE 19th International Symposium on Biomedical Imaging (ISBI)}, booktitle = {2022 IEEE 19th International Symposium on Biomedical Imaging (ISBI)}, doi = {10.1109/ISBI52829.2022.9761465}, pages = {1 -- 5}, abstract = {Large longitudinal studies provide lots of valuable information, especially in medical applications. A problem which must be taken care of in order to utilize their full potential is that of correlation between intra-subject measurements taken at different times. For data in Euclidean space this can be done with hierarchical models, that is, models that consider intra-subject and between-subject variability in two different stages. Nevertheless, data from medical studies often takes values in nonlinear manifolds. Here, as a first step, geodesic hierarchical models have been developed that generalize the linear ansatz by assuming that time-induced intra-subject variations occur along a generalized straight line in the manifold. However, this is often not the case (e.g., periodic motion or processes with saturation). We propose a hierarchical model for manifold-valued data that extends this to include trends along higher-order curves, namely B{\´e}zier splines in the manifold. To this end, we present a principled way of comparing shape trends in terms of a functional-based Riemannian metric. Remarkably, this metric allows efficient, yet simple computations by virtue of a variational time discretization requiring only the solution of regression problems. We validate our model on longitudinal data from the osteoarthritis initiative, including classification of disease progression.}, language = {en} } @article{NavaYazdaniHegevonTycowicz, author = {Nava-Yazdani, Esfandiar and Hege, Hans-Christian and von Tycowicz, Christoph}, title = {A Hierarchical Geodesic Model for Longitudinal Analysis on Manifolds}, series = {Journal of Mathematical Imaging and Vision}, volume = {64}, journal = {Journal of Mathematical Imaging and Vision}, number = {4}, doi = {10.1007/s10851-022-01079-x}, pages = {395 -- 407}, abstract = {In many applications, geodesic hierarchical models are adequate for the study of temporal observations. We employ such a model derived for manifold-valued data to Kendall's shape space. In particular, instead of the Sasaki metric, we adapt a functional-based metric, which increases the computational efficiency and does not require the implementation of the curvature tensor. We propose the corresponding variational time discretization of geodesics and employ the approach for longitudinal analysis of 2D rat skulls shapes as well as 3D shapes derived from an imaging study on osteoarthritis. Particularly, we perform hypothesis test and estimate the mean trends.}, language = {en} } @misc{SieberKuhnHegeetal., author = {Sieber, Moritz and Kuhn, Alexander and Hege, Hans-Christian and Paschereit, C. Oliver and Oberleithner, Kilian}, title = {A Graphical Representation of the Spectral Proper Orthogonal Decomposition}, series = {68th Annual Meeting of the APS Division of Fluid Dynamics, Gallery of Fluid Motion, Nov 22-24, 2015, Boston, MA, USA.}, journal = {68th Annual Meeting of the APS Division of Fluid Dynamics, Gallery of Fluid Motion, Nov 22-24, 2015, Boston, MA, USA.}, abstract = {We consider the spectral proper orthogonal decomposition (SPOD) for experimental data of a turbulent swirling jet. This newly introduced method combines the advantages of spectral methods, such as Fourier decomposition or dynamic mode decomposition, with the energy-ranked proper orthogonal decomposition (POD). This poster visualizes how the modal energy spectrum transitions from the spectral purity of Fourier space to the sparsity of POD space. The transition is achieved by changing a single parameter - the width of the SPOD filter. Each dot in the 3D space corresponds to an SPOD mode pair, where the size and color indicates its spectral coherence. What we notice is that neither the Fourier nor the POD spectrum achieves a clear separation of the dynamic phenomena. Scanning through the graph from the front plane (Fourier) to the back plane (POD), we observe how three highly coherent SPOD modes emerge from the dispersed Fourier spectrum and later branch out into numerous POD modes. The spatial properties of these three individual SPOD modes are displayed in the back of the graph using line integral convolution colored by vorticity. The first two modes correspond to single-helical global instabilities that are well known for these flows. Their coexistence, however, has not been observed until now. The third mode is of double- helical shape and has not been observed so far. For this considered data set and many others, the SPOD is superior in identification of coherent structures in turbulent flows. Hopefully, it gives access to new fluid dynamic phenomena and enriches the available methods.}, language = {en} } @inproceedings{NavaYazdaniHegevonTycowicz, author = {Nava-Yazdani, Esfandiar and Hege, Hans-Christian and von Tycowicz, Christoph}, title = {A Geodesic Mixed Effects Model in Kendall's Shape Space}, series = {Proc. 7th MICCAI workshop on Mathematical Foundations of Computational Anatomy (MFCA)}, volume = {11846}, booktitle = {Proc. 7th MICCAI workshop on Mathematical Foundations of Computational Anatomy (MFCA)}, doi = {10.1007/978-3-030-33226-6_22}, pages = {209 -- 218}, abstract = {In many applications, geodesic hierarchical models are adequate for the study of temporal observations. We employ such a model derived for manifold-valued data to Kendall's shape space. In particular, instead of the Sasaki metric, we adapt a functional-based metric, which increases the computational efficiency and does not require the implementation of the curvature tensor. We propose the corresponding variational time discretization of geodesics and apply the approach for the estimation of group trends and statistical testing of 3D shapes derived from an open access longitudinal imaging study on osteoarthritis.}, language = {en} } @inproceedings{KaehlerWiseAbeletal.2006, author = {K{\"a}hler, Ralf and Wise, John and Abel, Tom and Hege, Hans-Christian}, title = {A framework for interactive, high-quality volume rendering of cosmological simulations}, series = {Proc. Int. Workshop on Volume Graphics (VG06)}, booktitle = {Proc. Int. Workshop on Volume Graphics (VG06)}, publisher = {Eurographics / IEEE VGTC 2006}, address = {Boston}, pages = {103 -- 110}, year = {2006}, language = {en} }