TY - CHAP A1 - Kumano, Soichiro A1 - Kera, Hiroshi A1 - Yamasaki, Toshihiko T1 - Wide Two-Layer Networks can Learn from Adversarial Perturbations T2 - Proceedings of the Conference on Neural Information Processing Systems Y1 - 2024 ER - TY - CHAP A1 - Kera, Hiroshi A1 - Ishihara, Yuki A1 - Kambe, Yuta A1 - Vaccon, Tristan A1 - Yokoyama, Kazuhiro T1 - Learning to Compute Gr\"obner Bases T2 - Proceedings of the Conference on Neural Information Processing Systems Y1 - 2024 ER - TY - JOUR A1 - Krishnadas, Anirudh A1 - Sinha, Nidhi A1 - Kirchner, Tom A1 - Antony, Bobby T1 - Calculation of electron-impact ionization of various benzene derivatives JF - IOP Publications- Physica Scripta N2 - Calculations of the electron-impact ionization cross-section of pyrene, anthracene, benzoyl chloride, benzophenone, and phthalonitrile are reported over a wide energy range. A comparison of theoretical models, viz. spherical complex optical potential (SCOP), pixel counting method (PCM), and the binary encounter Bethe (BEB) model is carried out. SCOP calculations provide the inelastic cross-section, and the ionization cross-section is extracted from it. This result is modified with PCM, a model previously applied to ion collisions which takes geometric screening corrections into account. The BEB model is used as an independent approach to calculate the ionization cross-section. It is demonstrated that all model results are in reasonable agreement with each other. Comparison is also made with other theoretical data where available. Y1 - 2024 U6 - https://doi.org/10.1088/1402-4896/ad640a VL - 99 IS - 9 SP - 095403 ER - TY - THES A1 - Kasravi, Javad T1 - Completion of Missing Parts in Medical Images Using Generative Adversarial Networks and Transformers N2 - Image inpainting (image completion) is a technique to remove undesirable elements or fill missing (repair damaged) sections in an image [1]. In medical images, inpainting can be applied for various applications. Issues like image artifacts (e.g., metal artifacts in CT and MRI) can introduce alterations to medical images. In simpler terms, these artifacts may introduce unwanted elements or anomalies into the medical images. These unwanted elements can be replaced with appropriate intensity in the images. In the context of defect reconstruction, which involves repairing skull defects, medical images are taken. To design an implant for a defective skull, image inpainting can be applied to an image containing the defective skull. This process generates an image with skull tissue, which can then be utilized for implant design. Additionally, in situations involving a restricted field of view, such as when only accessing the lower part of the full-body MRI, predicting the missing information (e.g., the upper part of the full-body MRI) can be beneficial for subsequent tasks, such as extracting bone structures for 3D shape modeling studies. Another application of inpainting is observed during actual stereo-fluoroscopic X-ray measurements. In these measurements, the calibration grid, which is beneficial for correcting distortions, introduces unwanted black dots into the image content. These black dots need to be removed from the image and replaced with the appropriate intensity. This thesis extends an existing architecture named Mask-aware Transformer (MAT) to fill in missing information in medical scans. The proposed method utilizes Generative Adversarial Networks and a Mask-aware Swin Transformer. Various adjustments, including changes in data type, model architecture, and adaptation for multinode training, have been implemented to address missing information in three different datasets. In one of our datasets, where black dots disrupt the image content, we applied our method to fill in the missing information. The results indicate that our approach outperforms other model-driven methods. In the second dataset, we employed the German National Cohort full-body MRI dataset to train a network for predicting the upper part of the full-body MRI. The outcomes indicate that the generated 2D slices exhibit realism and perform well in both pixel-wise and perceptual metrics. However, when these 2D slices are stacked into a 3D volume, inconsistencies between different slices become apparent. Furthermore, when we compare our 2D-aware image inpainting method to 3D inpainting algorithms used in the Brain Tumor Segmentation 2023 challenge, the results confirm the findings of the earlier experiment. The 2D slices produced are realistic, but there is inconsistency between them. In summary, theMAT demonstrates its ability to capture global dependencies by utilizing an adapted Swin Transformer for X-ray images, inherently 2D images. The results for 2D slices from a 3D MRI volume are also reasonable because the network is trained specifically on 2D slices. However, due to the lack of awareness regarding this architecture in the third dimension, inconsistencies between slices are observed. KW - Image Inpainting KW - Generative Adversarial Networks KW - Swin Transformer KW - Mask-Tware Transformer Y1 - 2024 ER - TY - THES A1 - Lukanek, Sandra T1 - 3D Reconstruction of the Mandible from Panoramic Dental X-Ray Projections N2 - Panoramic radiography is a popular imaging technique in dental medicine. It omprehensively represents the entire jaw, including the mandible, maxilla, and teeth in a compact two-dimensional (2D) image. It offers several advantages over three-dimensional (3D) imaging, such as Cone Beam Computed Tomography (CBCT), including cost-effectiveness and reduced radiation exposure. However, its major drawback lies in its ambiguities in spatial distribution, leading to inaccuracies in linear measurements due to the dependency on the parameters used for generating the image. In this thesis, we propose a methodology for reconstructing a 3D anatomy of the mandible from a given 2D panoramic X-ray image. Our approach involves extracting information from the 2D scan, considering the projection geometry, and aiming to achieve a realistic spatial distribution. The methodology builds upon an existing intensity-based 2D-3D registration algorithm, which is modified to accommodate the unique geometric parameters of panoramic radiography. By employing a virtual X-ray setup, we generate a panoramic X-ray from a Statistical Shape and Intensity Model (SSIM) derived from 25 tetrahedral meshes. The intensity information for each mesh is extracted from CBCT scans representing jaw anatomies. To reconstruct the true mandible, the model is iteratively optimized by comparing the simulated X-ray with the original panoramic X-ray. We evaluate and establish the setup using synthetically generated panoramic X-rays from multiple mandibles obtained from CBCT scans. After analyzing the feasibility of this method, we conclude that 2D-3D registration for panoramic X-rays presents a challenging task, as the ambiguity of the 2D projection involved in panoramic X-ray imaging can result in varied 3D shape representations. Y1 - 2024 ER - TY - JOUR A1 - Ramos, Alejandro A1 - Fischer, Eric W. A1 - Saalfrank, Peter A1 - Kühn, Oliver T1 - Shaping the laser control landscape of a hydrogen transfer reaction by vibrational strong coupling. A direct optimal control approach JF - The Journal of Chemical Physics Y1 - 2024 ER - TY - CHAP A1 - Urbano, Alonso A1 - Romero, David W. T1 - Self-Supervised Detection of Perfect and Partial Input-Dependent Symmetries T2 - Proceedings of the Geometry-grounded Representation Learning and Generative Modeling Workshop (GRaM) at ICML 2024 Y1 - 2024 ER - TY - THES A1 - Eifler, Leon T1 - Algorithms and Certificates for Exact Mixed Integer Programming N2 - Mixed Integer Programming (MIP) is a powerful tool for solving optimization problems with discrete decisions. Although the problem class of mixed integer programs is NP-hard, MIP solvers have made significant progress in solving large-scale instances through decades of dedicated research and complex algorithmic improvements. In practice, virtually all algorithms to solve MIP problems are based on floating-point arithmetic due to its rapid computation times and robust numerical capabilities. Using error tolerances, MIP solvers avoid numerical issues and maintain a solution quality that is sufficient for most practical applications. There are, however, applications where exact solutions are required, such as when MIPs are employed as a tool in computer-assisted proofs. In such cases, exact, certified MIP solvers are a necessity. This thesis delves into the study and development of exact, certified mixed integer programming methods. The primary contribution of this thesis is an algorithmic framework for exact rational mixed integer programming. This framework incorporates safe dual bounding techniques, exact rational presolving, an exact repair step for heuristic solutions, and a novel exact Gomory mixed integer cut generator. We validate the effectiveness of our framework through experiments on a diverse set of benchmark instances. We take great care to measure the similarities and differences with corresponding techniques in the floating-point setting. Furthermore, we incorporate certification techniques into the framework to provide rigorous guarantees on the correctness of the computed solutions. We also provide a comprehensive algorithmic and computational study of the solver-independent verification of these certficates. We also present a framework for applying exact MIP as a tool for computer-assisted mathematics, using Chvátals conjecture as an illustrative example. Another significant contribution of this thesis is a new algorithm for solving linear programs exactly. This algorithm combines two state-of-the-art techniques for exact linear programming: precision boosting and LP iterative refinement. Combining these techniques can significantly improve the performance of exact linear programming solvers, and we prove that the algorithm is theoretically guaranteed to terminate with an exact solution. Y1 - 2024 U6 - https://doi.org/https://doi.org/10.14279/depositonce-23941 ER - TY - CHAP A1 - Hadjidimitriou, Natalia Selini A1 - Lippi, Marco A1 - Nastro, Raffaele A1 - Koch, Thorsten A1 - Mamei, Marco T1 - Short-Term Forecasting of Energy Consumption and Production in Local Energy Communities T2 - 2024 32nd International Conference on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE) Y1 - 2024 U6 - https://doi.org/10.1109/WETICE64632.2024.00022 SP - 74 EP - 79 PB - IEEE ER - TY - GEN A1 - Ragyanszki, Anita A1 - Ji, Hongchen A1 - Fournier, Rene T1 - Understanding the Origins of Life – A Machine learning approach to estimate reaction mechanisms of biotic precursors T2 - SIMPLAIX N2 - Understanding the Origins of Life - A Machine learning approach to estimate reaction mechanisms of biotic precursors. Life as we know it is the result of billions of years of evolution; however, understanding how the very first organisms came into existence is a challenge that has yet to be solved. One theory states that components of these molecules may have formed in the interstellar medium (ISM) and been transported to Earth. The ISM, with its specific conditions, allows for molecular stability and the formation of biotic precursors that would otherwise be unlikely in Earth's prebiotic conditions. Understanding how these molecules formed in the ISM may be the key to determining how life began. The goal of this research is to develop a model for solving astrobiophysical problems by studying the formation mechanisms of biomolecules found in the ISM. Although such pathways have been studied individually, there has not yet been a comprehensive method to understand the complete reactions mechanisms. Several QM methods are available for finding transition states (TS) and energy barriers (E) of chemical reactions but are time-consuming and can hardly be applied to more complex systems. Our interest is to develop a machine learning approach to approximate TS, and E, requiring as input only estimates of geometry and energies of reactants and products. Y1 - 2024 ER - TY - GEN A1 - Ragyanszki, Anita A1 - Ji, Hongchen A1 - Fournier, Rene T1 - Understanding the Origins of Life - A Machine learning approach to estimate reaction mechanisms of biotic precursors T2 - Perspectives and challenges of future HPC installations for atomistic and molecular simulations N2 - Life as we know it is the result of billions of years of evolution; yet, understanding how the very first organisms came into existence is a challenge that has yet to be solved. One theory states that components of the first biotic molecules may not have formed on Earth. Rather, they may have initially formed in the interstellar medium (ISM) and been transported to Earth, as supported by recorded instances of organic molecules detected in space. The ISM, with its low temperatures and specific collision processes, allows for molecular stability and the formation of biotic precursors that would otherwise be unlikely in Earth's prebiotic conditions. Understanding how these molecules formed in the ISM may be the key to determining how life began. The goal of this research is to develop a new model for solving astrobiophysical problems by studying the formation mechanisms of biomolecules found in the ISM. Although such pathways have been studied individually, there has not yet been a comprehensive method to understand all the formation reactions that can occur in ISM. Several quantum chemical and numerical methods are available for finding transition states (TS) and energy barriers (E) of chemical reactions but are time-consuming and can hardly be applied to systems with more than a few atoms. Our main interest is to develop a a machine learning approach to approximate TS, and E, requiring as input only estimates of geometry and energies of reactants and products. Using a complete dataset 300 reaction features are computed, and an estimate of E is obtained by fitting a Kernel Ridge Regression (KRR) model with Laplacian kernel, and a fully connected Artificial Neural Network (ANN) to estimate reaction energy barriers. Y1 - 2024 ER - TY - JOUR A1 - Ji, Hongchen A1 - Ragyanszki, Anita A1 - Fournier, Rene T1 - A Machine Learning and Quantum Chemistry Approach for Identifying Prebiotic Molecules in the Interstellar Medium JF - Physical Chemistry Chemical Physics N2 - The discovery of molecules in the interstellar medium (ISM) plays a key role in understanding prebiotic chemistry. Relatively few (∼250) molecules have been confirmed in the ISM, and detecting additional species is crucial for expanding our knowledge of astrochemical processes. We present a strategy for predicting possible prebiotic molecules in the ISM that combines machine learning and high-accuracy quantum chemistry calculations. Using a reaction dataset of over 153,000 possible combinations of known interstellar molecules, we applied a machine learning model to estimate reaction energy barriers and identify those with low or zero barriers that are most likely to occur in the ISM. From this screening process, 24 molecules were identified, five of which have already been observed in interstellar space. For the remaining 19 molecules, we conducted density functional theory (DFT) and coupled cluster theory calculations to determine the most stable conformers, spectroscopic parameters, and predict their detectability through spectroscopy. We present data to guide future observational searches for new interstellar species, contributing to the ongoing exploration of complex organic molecules in space and their potential role in prebiotic chemistry. Y1 - 2024 ER - TY - JOUR A1 - Euler, Ricardo A1 - Maristany de las Casas, Pedro A1 - Borndörfer, Ralf T1 - Logic-Constrained Shortest Paths for Flight Planning N2 - The Logic-Constrained Shortest Path Problem (LCSP) combines a one-to-one shortest path problem with satisfiability constraints imposed on the routing graph. This setting arises in flight planning, where air traffic control (ATC) authorities are enforcing a set of traffic flow restrictions (TFRs) on aircraft routes in order to increase safety and throughput. We propose a new branch and bound-based algorithm for the LCSP. The resulting algorithm has three main degrees of freedom: the node selection rule, the branching rule and the conflict. While node selection and branching rules have been long studied in the MIP and SAT communities, most of them cannot be applied out of the box for the LCSP. We review the existing literature and develop tailored variants of the most prominent rules. The conflict, the set of variables to which the branching rule is applied, is unique to the LCSP. We analyze its theoretical impact on the B&B algorithm. In the second part of the paper, we show how to model the Flight Planning Problem with TFRs as an LCSP and solve it using the branch and bound algorithm. We demonstrate the algorithm’s efficiency on a dataset consisting of a global flight graph and a set of around 20000 real TFRs obtained from our industry partner Lufthansa Systems GmbH. We make this dataset publicly available. Finally, we conduct an empirical in-depth analysis of node selection rules, branching rules and conflicts. Carefully choosing an appropriate combination yields an improvement of an order of magnitude compared to an uninformed choice. Y1 - 2024 ER - TY - JOUR A1 - Becks, Henrik A1 - Lippold, Lukas A1 - Winkler, Paul A1 - Rohrer, Maximilian A1 - Leusmann, Thorsten A1 - Anton, David A1 - Sprenger, Bjarne A1 - Kähler, Philipp A1 - Rudenko, Iryna A1 - Andrés Arcones, Daniel A1 - Koutsourelakis, Phaedon-Stelios A1 - Unger, Jörg F. A1 - Weiser, Martin A1 - Petryna, Yuri A1 - Schnellenbach-Held, Martina A1 - Lowke, Dirk A1 - Wessels, Henning A1 - Lenzen, Armin A1 - Zabel, Volkmar A1 - Könke, Carsten A1 - Claßen, Martin A1 - Hegger, Josef T1 - Neuartige Konzepte für die Zustandsüberwachung und -analyse von Brückenbauwerken – Einblicke in das Forschungsvorhaben SPP100+ JF - Bauingenieur N2 - Die Brückeninfrastruktur in Deutschland und Europa steht aufgrund steigender Verkehrslasten und alternder Bauwerke vor erheblichen Herausforderungen. Das DFG-Schwerpunktprogramm 2388 „Hundert plus – Verlängerung der Lebensdauer komplexer Baustrukturen durch intelligente Digitalisierung“ (SPP100+) strebt an, durch digitale Innovationen und prädiktive Instandhaltungsstrategien die Nutzungsdauer bestehender Brückenbauwerke zu verlängern. Der vorliegende Beitrag fokussiert sich auf das SPP100+ zugehörige Cluster „Monitoring und Simulation“, das sieben Teilprojekte umfasst. Die Projekte entwickeln fortschrittliche Methoden zur Überwachung und Zustandsbewertung von Brücken mittels Digitaler Zwillinge, hochauflösender Sensortechnik und numerischer Simulationen. Innovative Ansätze wie nichtlineare Modellanpassungen, stochastische Methoden und künstliche Intelligenz ermöglichen eine präzise und frühzeitige Identifizierung potenzieller Schäden. Die Kombination aus kontinuierlichem Bauwerksmonitoring und effizienter Datenauswertung ist entscheidend für die langfristige Sicherheit und Langlebigkeit bestehender Brücken und trägt darüber hinaus zur Ressourcenschonung bei. N2 - Bridges in Germany and across Europe face significant challenges due to increasing traffic loads and aging structures. The DFG Priority Programme 2388 “Hundred Plus – Extending the Lifetime of Complex Engineering Structures through Intelligent Digitalization” (SPP100+) aims to extend the lifespan of existing bridge structures through digital innovations and predictive maintenance strategies. This paper focuses on the SPP100+ affiliated cluster “Monitoring and Simulation,” which encompasses seven sub-projects. These projects develop advanced methods for monitoring and assessing the condition of bridge structures using digital twins, high-resolution sensor technology, and numerical simulations. Innovative approaches such as nonlinear model adjustments, stochastic methods, and artificial intelligence facilitate precise and early identification of potential damages. The combination of continuous structural monitoring and efficient data evaluation is crucial for the long-term reliability and durability of existing bridges and contributes to resource conservation. T2 - Novel Concepts for the Condition Monitoring and Analysis of Bridge Structures – Insights into the SPP100+ Research Project Y1 - 2024 U6 - https://doi.org/10.37544/0005-6650-2024-10-63 VL - 99 IS - 10 SP - 327 EP - 338 ER - TY - CHAP A1 - Siqueira Rodrigues, Lucas A1 - Nyakatura, John A1 - Zachow, Stefan A1 - Israel, Johann Habakuk A1 - Kosch, Thomas T1 - Evaluating Visuohaptic Integration on Memory Retention of Morphological Tomographic Images T2 - The 19th ACM SIGGRAPH International Conference on Virtual-Reality Continuum and its Applications in Industry N2 - Scientific visualization and tomographic imaging techniques have created unprecedented possibilities for non-destructive analyses of digital specimens in morphology. However, practitioners encounter difficulties retaining critical information from complex tomographic volumes in their workflows. In light of this challenge, we investigated the effectiveness of visuohaptic integration in enhancing memory retention of morphological data. In a within-subjects user study (N=18), participants completed a delayed match-to-sample task, where we compared error rates and response times across visual and visuohaptic sensory modality conditions. Our results indicate that visuohaptic encoding improves the retention of tomographic images, producing significantly reduced error rates and faster response times than its unimodal visual counterpart. Our findings suggest that integrating haptics into scientific visualization interfaces may support professionals in fields such as morphology, where accurate retention of complex spatial data is essential for efficient analysis and decision-making within virtual environments. Y1 - 2024 U6 - https://doi.org/10.1145/3703619.3706055 SP - 1 EP - 10 PB - ACM CY - New York, NY, USA ER - TY - JOUR A1 - Regényi, Enikő A1 - Mashreghi, Mir-Farzin A1 - Schütte, Christof A1 - Sunkara, Vikram T1 - Exploring transcription modalities from bimodal, single-cell RNA sequencing data JF - NAR Genomics and Bioinformatics N2 - Abstract There is a growing interest in generating bimodal, single-cell RNA sequencing (RNA-seq) data for studying biological pathways. These data are predominantly utilized in understanding phenotypic trajectories using RNA velocities; however, the shape information encoded in the two-dimensional resolution of such data is not yet exploited. In this paper, we present an elliptical parametrization of two-dimensional RNA-seq data, from which we derived statistics that reveal four different modalities. These modalities can be interpreted as manifestations of the changes in the rates of splicing, transcription or degradation. We performed our analysis on a cell cycle and a colorectal cancer dataset. In both datasets, we found genes that are not picked up by differential gene expression analysis (DGEA), and are consequently unnoticed, yet visibly delineate phenotypes. This indicates that, in addition to DGEA, searching for genes that exhibit the discovered modalities could aid recovering genes that set phenotypes apart. For communities studying biomarkers and cellular phenotyping, the modalities present in bimodal RNA-seq data broaden the search space of genes, and furthermore, allow for incorporating cellular RNA processing into regulatory analyses. Y1 - 2024 U6 - https://doi.org/10.1093/nargab/lqae179 SN - 2631-9268 VL - 6 IS - 4 PB - Oxford University Press (OUP) ER - TY - JOUR A1 - Andrés Arcones, Daniel A1 - Weiser, Martin A1 - Koutsourelakis, Phaedon-Stelios A1 - Unger, Jörg F. T1 - Bias Identification Approaches for Model Updating of Simulation-based Digital Twins of Bridges JF - Structural Health Monitoring in the Light of Climate Impact and Data Science. Research and Review Journal of Nondestructive Testing N2 - Simulation-based digital twins of bridges have the potential not only to serve as monitoring devices of the current state of the structure but also to generate new knowledge through physical predictions that allow for better-informed decisionmaking. For an accurate representation of the bridge, the underlying models must be tuned to reproduce the real system. Nevertheless, the necessary assumptions and simplifications in these models irremediably introduce discrepancies between measurements and model response. We will show that quantifying the extent of the uncertainties introduced through the models that lead to such discrepancies provides a better understanding of the real system, enhances the model updating process, and creates more robust and trustworthy digital twins. The inclusion of an explicit bias term will be applied to a representative demonstrator case based on the thermal response of the Nibelungenbrücke of Worms. The findings from this work are englobed in the initiative SPP 100+, whose main aim is the extension of the service life of structures, especially through the implementation of digital twins. Y1 - 2024 U6 - https://doi.org/10.58286/30524 VL - 2 IS - 2 ER - TY - JOUR A1 - Harth, Philipp A1 - Udvary, Daniel A1 - Boelts, Jan A1 - Baum, Daniel A1 - Macke, Jakob H. A1 - Hege, Hans-Christian A1 - Oberlaender, Marcel T1 - Dissecting origins of wiring specificity in dense cortical connectomes JF - bioRxiv N2 - Wiring specificity in the cortex is observed across scales from the subcellular to the network level. It describes the deviations of connectivity patterns from those expected in randomly connected networks. Understanding the origins of wiring specificity in neural networks remains difficult as a variety of generative mechanisms could have contributed to the observed connectome. To take a step forward, we propose a generative modeling framework that operates directly on dense connectome data as provided by saturated reconstructions of neural tissue. The computational framework allows testing different assumptions of synaptic specificity while accounting for anatomical constraints posed by neuron morphology, which is a known confounding source of wiring specificity. We evaluated the framework on dense reconstructions of the mouse visual and the human temporal cortex. Our template model incorporates assumptions of synaptic specificity based on cell type, single-cell identity, and subcellular compartment. Combinations of these assumptions were sufficient to model various connectivity patterns that are indicative of wiring specificity. Moreover, the identified synaptic specificity parameters showed interesting similarities between both datasets, motivating further analysis of wiring specificity across species. Y1 - 2024 U6 - https://doi.org/10.1101/2024.12.14.628490 ER - TY - GEN A1 - Binkowski, Felix A1 - Betz, Fridtjof A1 - Hammerschmidt, Martin A1 - Zschiedrich, Lin A1 - Burger, Sven T1 - Source code and simulation results: Resonance modes in microstructured photonic waveguides - Efficient and accurate computation based on AAA rational approximation T2 - Zenodo Y1 - 2024 U6 - https://doi.org/10.5281/zenodo.14202408 SP - doi: 10.5281/zenodo.14202408 ER - TY - JOUR A1 - Clausecker, Robert A1 - Lemire, Daniel A1 - Schintke, Florian T1 - Faster Positional-Population Counts for AVX2, AVX-512, and ASIMD JF - CoRR Y1 - 2024 U6 - https://doi.org/10.48550/arXiv.2412.16370 VL - abs/2412.16370 SP - 1 EP - 23 ER - TY - JOUR A1 - Trepczynski, Adam A1 - Kneifel, Paul A1 - Heyland, Mark A1 - Leskovar, Marko A1 - Moewis, Philippe A1 - Damm, Philipp A1 - Taylor, William R. A1 - Zachow, Stefan A1 - Duda, Georg T1 - Impact of the External Knee Flexion Moment on Patello-Femoral Loading Derived from in vivo Loads and Kinematics JF - Frontiers in Bioengineering and Biotechnology N2 - Anterior knee pain and other patello-femoral (PF) complications frequently limit the success of total knee arthroplasty as the final treatment of end stage osteoarthritis. However, knowledge about the invivo loading conditions at the PF joint remains limited, as no direct measurements are available. We hypothesised that the external knee flexion moment (EFM) is highly predictive of the PF contact forces during activities with substantial flexion of the loaded knee.Six patients (65-80 years, 67-101 kg) with total knee arthroplasty (TKA) performed two activities of daily living: sit-stand-sit and squat. Tibio-femoral (TF) contact forces were measured in vivo using instrumented tibial components, while synchronously internal TF and PF kinematics were captured with mobile fluoroscopy. The measurements were used to compute PF contact forces using patient specific musculoskeletal models. The relationship between the EFM and the PF contact force was quantified using linear regression.Mean peak TF contact forces of 1.97 to 3.24 times body weight (BW) were found while peak PF forces reached 1.75 to 3.29 times body weight (BW). The peak EFM ranged from 3.2 to 5.9 %BW times body height, and was a good predictor of the PF contact force (R^2 = 0.95 and 0.88 for sit-standsit and squat, respectively).The novel combination of in vivo TF contact forces and internal patellar kinematics enabled a reliable assessment of PF contact forces. The results of the regression analysis suggest that PF forces can be estimated based solely on the EFM from quantitative gait analysis. Our study also demonstrates the relevance of PF contact forces, which reach magnitudes similar to TF forces during activities of daily living. Y1 - 2024 U6 - https://doi.org/10.3389/fbioe.2024.1473951 VL - 12 ER - TY - THES A1 - Ernst, Ariane T1 - Mathematical modeling and analysis of neurotransmission N2 - Modeling and simulation of neurotransmission plays a central role in the scientific investigation of synaptic functioning and neuronal communication. Understanding the neurotransmission process is crucial due to its fundamental significance in cognitive function, with impairments in this process potentially giving rise to severe pathological conditions. Existing modeling approaches capture the dynamic behavior and the probabilistic properties of the synaptic machinery utilizing results from stochastic chemical kinetics. However, the underlying mathematical theory rarely receives detailed consideration. In this thesis, we explore the neurotransmission process from a mathematical perspective and provide important insights that improve efficiency in its modeling and simulation. We introduce a new method for the direct and exact computation of first- and second-order moments of the postsynaptic current for the case of linear reaction networks, circumventing previously employed stochastic simulations. The approach hinges on the computation of the cross-correlation functions for the associated Markov jump process and their characterization by a partial differential equation. Our method can be applied to efficiently compare coarse-graining strategies for neurotransmission models, which we demonstrate for a significant recent model of synaptic vesicle release. We also numerically analyze the feasibility of reducing this particular model and show that a reduction can preserve the characteristics of the mean output current and its standard deviation to a satisfactory degree under typical stimulation conditions, where the approximation error can even be neglected depending on release site position. As the dependency on the local calcium concentration is preserved in the reduced model, it can be subjected to arbitrary types of signals in future studies. Moreover, we investigate the recovery processes of synaptic vesicles and release sites by introducing a nonlinear model with explicit recovery reactions. A sensitivity analysis provides the novel insight that the widely debated identity of the limiting recovery process during sustained stimulation is time-dependent. For our model, the output current’s first-order moment and its deterministic approximation show an exceptionally high level of agreement. We determine this to be an inherent consequence of the model structure due to the independence of the two recovery processes, supporting future use of the deterministic approximation. Parameter estimations confirm our model’s capability of reproducing experimental data. Y1 - 2024 ER - TY - JOUR A1 - Hintermüller, Michael A1 - Stengl, Steven-Marian T1 - A Generalized 𝛤-Convergence Concept for a Class of Equilibrium Problems JF - Journal of Nonlinear Science Y1 - 2024 U6 - https://doi.org/10.1007/s00332-024-10059-x VL - 34 IS - 83 ER - TY - JOUR A1 - Gelß, Patrick A1 - Issagali, Aizhan A1 - Kornhuber, Ralf T1 - Fredholm integral equations for function approximation and the training of neural networks JF - SIAM Journal on Mathematics of Data Science Y1 - 2024 U6 - https://doi.org/10.1137/23M156642X VL - 6 IS - 4 ER - TY - JOUR A1 - Stengl, Steven-Marian T1 - An alternative formulation of the quantum phase estimation using projection-based tensor decompositions JF - Quantum Information Processing Y1 - 2024 U6 - https://doi.org/10.1007/s11128-024-04347-4 VL - 23 ER - TY - GEN A1 - Roche, Léo J. A1 - Betz, Fridtjof A1 - Yang, Yuhui A1 - Limame, Imad A1 - Shih, Ching-Wen A1 - Burger, Sven A1 - Reitzenstein, Stephan T1 - Inside Front Cover: Numerical Investigation of a Coupled Micropillar - Waveguide System for Integrated Quantum Photonic Circuits (Adv. Quantum Technol. 12/2024) T2 - Adv. Quantum Technol. Y1 - 2024 U6 - https://doi.org/10.1002/qute.202470036 VL - 7 SP - 2470036 ER - TY - GEN A1 - Kempke, Nils-Christian A1 - Rehfeldt, Daniel A1 - Koch, Thorsten T1 - A Massively Parallel Interior-Point-Method for Arrowhead Linear Programs N2 - In practice, non-specialized interior point algorithms often cannot utilize the massively parallel compute resources offered by modern many- and multi-core compute platforms. However, efficient distributed solution techniques are required, especially for large-scale linear programs. This article describes a new decomposition technique for systems of linear equations implemented in the parallel interior-point solver PIPS-IPM++. The algorithm exploits a matrix structure commonly found in optimization problems: a doubly-bordered block-diagonal or arrowhead structure. This structure is preserved in the linear KKT systems solved during each iteration of the interior-point method. We present a hierarchical Schur complement decomposition that distributes and solves the linear optimization problem; it is designed for high-performance architectures and scales well with the availability of additional computing resources. The decomposition approach uses the border constraints’ locality to decouple the factorization process. Our approach is motivated by large-scale unit-commitment problems. We demonstrate the performance of our method on a set of mid-to large-scale instances, some of which have more than 10^9 nonzeros in their constraint matrix. T3 - ZIB-Report - 24-13 KW - direct methods for linear systems KW - mathematical programming KW - parallel computation KW - linear programming KW - large-scale problems KW - interior-point methods Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-98829 SN - 1438-0064 ER - TY - JOUR A1 - Komnik, Igor A1 - Funken, Johannes A1 - Zachow, Stefan A1 - Schmidt-Wiethoff, Rüdiger A1 - Ellermann, Andree A1 - Potthast, Wolfgang T1 - Surgical planning in HTO – Alternative approaches to the Fujisawa gold-standard JF - Technology and Health Care N2 - BACKGROUND: Presurgical planning of the correction angle plays a decisive role in a high tibial osteotomy, affecting the loading situation in the knee affected by osteoarthritis. The planning approach by Fujisawa et al. aims to adjust the weight-bearing line to achieve an optimal knee joint load distribution. While this method is accessible, it may not fully consider the complexity of individual dynamic knee-loading profiles. This review aims to disclose existing alternative HTO planning methods that do not follow Fujisawa’s standard. METHODS: PubMed, Web of Science and CENTRAL databases were screened, focusing on HTO research in combination with alternative planning approaches. RESULTS: Eight out of 828 studies were included, with seven simulation studies based on finite element analysis and multi-body dynamics. The planning approaches incorporated gradual degrees of realignment parameters (weight-bearing line shift, medial proximal tibial angle, hip- knee-ankle, knee joint line orientation), simulating their effect on knee kinematics, contact force/stress, Von Mises and shear stress. Two studies proposed implementing individual correction magnitudes derived from preoperatively predicted knee adduction moments. CONCLUSION: Most planning methods depend on static alignment assessments, neglecting an adequate loading-depending profile. They are confined to their conceptual phases, making the associated planning methods unviable for current clinical use. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-98227 ER - TY - GEN A1 - Hosoda, Junko A1 - Maher, Stephen J. A1 - Shinano, Yuji T1 - Combining Benders’ decomposition and parallelisation to solve large-scale adaptive network supply chain management problems N2 - Integrated supply chain network design—combining warehouse clustering with inter- and intra-cluster vehicle routing—is a fundamental feature of supply chain management problems. In this paper, a Benders’ decomposition-based parallel heuristic approach for the integrated long-haul and local vehicle routing problem is proposed. The proposed algorithm comprises lower- and upper-bound search algorithms running in parallel to find high-quality solutions for challenging supply chain management problems. A novel Benders’ decomposition approach is proposed to aid the improvement in the lower bound for large-scale problems. The results demonstrate that the Benders’ decomposition approach is effective in finding strong lower bounds and is beneficial for obtaining high-quality solutions. T3 - ZIB-Report - 24-12 Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-98744 SN - 1438-0064 ER - TY - JOUR A1 - Mayer, Julius A1 - Baum, Daniel A1 - Ambellan, Felix A1 - von Tycowicz, Christoph A1 - for the Alzheimer’s Disease Neuroimaging Initiative, T1 - Shape-based Disease Grading via Functional Maps and Graph Convolutional Networks with Application to Alzheimer’s Disease JF - BMC Medical Imaging N2 - Shape analysis provides methods for understanding anatomical structures extracted from medical images. However, the underlying notions of shape spaces that are frequently employed come with strict assumptions prohibiting the analysis of incomplete and/or topologically varying shapes. This work aims to alleviate these limitations by adapting the concept of functional maps. Further, we present a graph-based learning approach for morphometric classification of disease states that uses novel shape descriptors based on this concept. We demonstrate the performance of the derived classifier on the open-access ADNI database differentiating normal controls and subjects with Alzheimer’s disease. Notably, the experiments show that our approach can improve over state-of-the-art from geometric deep learning. Y1 - 2024 U6 - https://doi.org/10.1186/s12880-024-01513-z VL - 24 ER - TY - GEN A1 - Vu, Thi Huong A1 - Koch, Thorsten A1 - Xu, Hong-Kun T1 - The gradient projection method: Is the Polyak adaptive stepsize rule optimal? N2 - Not always! This is our answer to the question of whether the Polyak adaptive stepsize rule in the gradient projection method is optimal. The answer is based on revisiting the subgradient projection method by Polyak [USSR Computational Mathematics and Mathematical Physics 9 (1969)] for smooth and convex minimization problems where the objective function possesses a geometric property called flatness. Our results show that the method can be more flexible (the effective range for the parameter controlling the stepsize can be wider) and have sharper convergence rates. Applications to split feasibility/equality problems are presented, deriving for the first time the O(1/k) rate of convergence for the adaptive CQ method. A theoretical guarantee of the linear convergence of the gradient descent method with adaptive stepsizes for Google PageRank is provided. At the same time, numerical experiments are designed to spot the ``optimal" stepsize and to compare with other basic gradient methods. Y1 - 2024 ER - TY - THES A1 - Jami, Masoud T1 - Optimizing Checkpoint/Restart and Input/Output for Large Scale Applications Y1 - 2024 UR - https://doi.org/10.18452/29985 U6 - https://doi.org/10.18452/29985 PB - Humboldt-Universität zu Belin ER - TY - THES A1 - Lücke, Marvin T1 - Concentration effects and collective variables in dynamical systems on networks Y1 - 2024 U6 - https://doi.org/10.17169/refubium-45325 ER - TY - JOUR A1 - Sperber, Wolfram T1 - Die Geschichte der Mathematischen Gesellschaft der DDR (Teil II): von der Gründung bis zur Wende JF - Mathematische Semesterberichte N2 - Der Artikel beschreibt die Tätigkeit und die Rahmenbedingungen der Mathematischen Gesellschaft der DDR, MGDDR, von der Gründung bis zur Wende. Er setzt die Darstellung der Vorgeschichte der MGDDR fort, die aus den Entwicklungen Deutschlands nach dem II. Weltkrieg resultiert. Einerseits entwickelte die MGDDR in der DDR ein eigenständiges mathematisches Leben und förderte vielfältige Aktivitäten in der mathematischen Schulbildung und Weiterbildung, andererseits war die MGDDR in die Politik von Partei und Staat in der DDR eingebunden, was sich etwa in der Überwachung und Verhinderung von Kontakten zu mathematischen Fachgesellschaften und Mathematikern aus nicht-sozialistischen Ländern zeigte. Y1 - 2024 U6 - https://doi.org/10.1007/s00591-024-00379-0 VL - 72 IS - 2 SP - 135 EP - 191 ER - TY - GEN A1 - Betz, Fridtjof A1 - Hammerschmidt, Martin A1 - Zschiedrich, Lin A1 - Burger, Sven A1 - Binkowski, Felix T1 - Efficient Rational Approximation of Optical Response Functions with the AAA Algorithm (Laser Photonics Rev. 18(11)/2024) T2 - Laser Photonics Rev. Y1 - 2024 U6 - https://doi.org/10.1002/lpor.202470071 VL - 18 SP - 2470071 ER - TY - JOUR A1 - Hosoda, Junko A1 - Maher, Stephen J. A1 - Shinano, Yuji A1 - Villumsen, Jonas Christoffer T1 - A parallel branch-and-bound heuristic for the integrated long-haul and local vehicle routing problem on an adaptive transportation network JF - Computers & Operations Research N2 - Consolidation of commodities and coordination of vehicle routes are fundamental features of supply chain management problems. While locations for consolidation and coordination are typically known a priori, in adaptive transportation networks this is not the case. The identification of such consolidation locations forms part of the decision making process. Supply chain management problems integrating the designation of consolidation locations with the coordination of long haul and local vehicle routing is not only challenging to solve, but also very difficult to formulate mathematically. In this paper, the first mathematical model integrating location clustering with long haul and local vehicle routing is proposed. This mathematical formulation is used to develop algorithms to find high quality solutions. A novel parallel framework is developed that combines exact and heuristic methods to improve the search for high quality solutions and provide valid bounds. The results demonstrate that using exact methods to guide heuristic search is an effective approach to find high quality solutions for difficult supply chain management problems. Y1 - 2024 U6 - https://doi.org/10.1016/j.cor.2024.106570 SN - 0305-0548 VL - 165 PB - Elsevier BV ER - TY - JOUR A1 - Fujii, Koichi A1 - Kim, Sunyoung A1 - Kojima, Masakazu A1 - Mittelmann, Hans D. A1 - Shinano, Yuji T1 - An exceptionally difficult binary quadratic optimization problem with symmetry: a challenge for the largest unsolved QAP instance Tai256c JF - Optimization Letters N2 - Tai256c is the largest unsolved quadratic assignment problem (QAP) instance in QAPLIB. It is known that QAP tai256c can be converted into a 256 dimensional binary quadratic optimization problem (BQOP) with a single cardinality constraint which requires the sum of the binary variables to be 92. As the BQOP is much simpler than the original QAP, the conversion increases the possibility to solve the QAP. Solving exactly the BQOP, however, is still very difficult. Indeed, a 1.48% gap remains between the best known upper bound (UB) and lower bound (LB) of the unknown optimal value. This paper shows that the BQOP admits a nontrivial symmetry, a property that makes the BQOP very hard to solve. Despite this difficulty, it is imperative to decrease the gap in order to ultimately solve the BQOP exactly. To effectively improve the LB, we propose an efficient BB method that incorporates a doubly nonnegative relaxation, the orbit branching and the isomorphism pruning. With this BB method, a new LB with 1.25% gap is successfully obtained, and computing an LB with gap is shown to be still quite difficult. Y1 - 2024 U6 - https://doi.org/10.1007/s11590-024-02157-2 SN - 1862-4472 PB - Springer Science and Business Media LLC ER - TY - GEN A1 - Schintke, Florian A1 - Greve, Nico A1 - de Cuveland, Jan ED - Friese, Volker ED - Gasik, Piotr ED - Selyuzhenkov, Ilya T1 - Recent Flesnet developments and work in progress T2 - CBM Progress Report 2023 Y1 - 2024 U6 - https://doi.org/10.15120/GSI-2024-00765 SP - 132 PB - GSI Helmholtzzentrum für Schwerionenforschung GmbH ER - TY - CHAP A1 - Mukherjee, Deshabrato A1 - Burger, Sven A1 - Siefke, Thomas A1 - Gour, Jeetendra A1 - Bodermann, Bernd A1 - Petrik, Peter T1 - Modeling of dimensions and sensing properties of gold gratings by spectroscopic ellipsometry and finite element method T2 - EPJ Web of Conferences Y1 - 2024 U6 - https://doi.org/10.1051/epjconf/202430902016 VL - 309 SP - 02016 ER - TY - CHAP A1 - Hadjidimitriou, Natalia Selini A1 - Koch, Thorsten A1 - Lippi, Marco A1 - Petkovic, Milena A1 - Mamei, Marco T1 - Analysis of the Impact of COVID-19 and Russo-Ukraine War on Natural Gas Flow Using Time Series Forecasting T2 - Preceedings of the 16th International Conference on Management of Digital Ecosystems Y1 - 2024 ER - TY - JOUR A1 - Abbas, Amira A1 - Ambainis, Andris A1 - Augustino, Brandon A1 - Bärtschi, Andreas A1 - Buhrman, Harry A1 - Coffrin, Carleton A1 - Cortiana, Giorgio A1 - Dunjko, Vedran A1 - Egger, Daniel J. A1 - Elmegreen, Bruce G. A1 - Franco, Nicola A1 - Fratini, Filippo A1 - Fuller, Bryce A1 - Gacon, Julien A1 - Gonciulea, Constantin A1 - Gribling, Sander A1 - Gupta, Swati A1 - Hadfield, Stuart A1 - Heese, Raoul A1 - Kircher, Gerhard A1 - Kleinert, Thomas A1 - Koch, Thorsten A1 - Korpas, Georgios A1 - Lenk, Steve A1 - Marecek, Jakub A1 - Markov, Vanio A1 - Mazzola, Guglielmo A1 - Mensa, Stefano A1 - Mohseni, Naeimeh A1 - Nannicini, Giacomo A1 - O’Meara, Corey A1 - Tapia, Elena Peña A1 - Pokutta, Sebastian A1 - Proissl, Manuel A1 - Rebentrost, Patrick A1 - Sahin, Emre A1 - Symons, Benjamin C. B. A1 - Tornow, Sabine A1 - Valls, Víctor A1 - Woerner, Stefan A1 - Wolf-Bauwens, Mira L. A1 - Yard, Jon A1 - Yarkoni, Sheir A1 - Zechiel, Dirk A1 - Zhuk, Sergiy A1 - Zoufal, Christa T1 - Challenges and opportunities in quantum optimization JF - Nature Reviews Physics Y1 - 2024 U6 - https://doi.org/10.1038/s42254-024-00770-9 SN - 2522-5820 VL - 6 SP - 718 EP - 735 PB - Springer Science and Business Media LLC ER - TY - JOUR A1 - Kostré, Margarita A1 - Djurdjevac Conrad, Natasa A1 - Schütte, Christof A1 - Sunkara, Vikram T1 - Exploration of Particle Swarm Optimisation Algorithm with Divergent Parameters JF - Natural Computing Y1 - 2024 ER - TY - JOUR A1 - Siqueira Rodrigues, Lucas A1 - Schmidt, Timo Torsten A1 - Nyakatura, John A1 - Zachow, Stefan A1 - Israel, Johann Habakuk A1 - Kosch, Thomas T1 - Assessing the Effects of Sensory Modality Conditions on Object Retention across Virtual Reality and Projected Surface Display Environments JF - Proceedings of the ACM on Human-Computer Interaction N2 - Haptic feedback reportedly enhances human interaction with 3D data, particularly improving the retention of mental representations of digital objects in immersive settings. However, the effectiveness of visuohaptic integration in promoting object retention across different display environments remains underexplored. Our study extends previous research on the retention effects of haptics from virtual reality to a projected surface display to assess whether earlier findings generalize to 2D environments. Participants performed a delayed match-to-sample task incorporating visual, haptic, and visuohaptic sensory feedback within a projected surface display environment. We compared error rates and response times across these sensory modalities and display environments. Our results reveal that visuohaptic integration significantly enhances object retention on projected surfaces, benefiting task performance across display environments. Our findings suggest that haptics can improve object retention without requiring fully immersive setups, offering insights for the design of interactive systems that assist professionals who rely on precise mental representations of digital objects. Y1 - 2024 U6 - https://doi.org/10.1145/3698137 VL - 8 IS - ISS SP - 255 EP - 282 ER - TY - JOUR A1 - Fritsch, Daniel A1 - Schorr, Susan T1 - Disorder induced band gap lowering in kesterite type Cu2ZnSnSe4 and Ag2ZnSnSe4: a first-principles and special quasirandom structures investigation JF - Journal of Physics: Condensed Matter N2 - Abstract Quaternary chalcogenides, i.e. Cu2ZnSnS4, crystallising in the kesterite crystal structure have already been demonstrated as potential building blocks of thin film solar cells, containing only abundant elements and exhibiting power conversion efficiencies of about 14.9% so far. However, due to the potential presence of several structurally similar polymorphs, the unequivocal identification of their ground state crystal structures required the application of more elaborate neutron diffraction experiments. One particular complication arose from the later identified Cu–Zn disorder, present in virtually all thin film samples. Subsequently, it has been shown experimentally that this unavoidable Cu–Zn disorder leads to a band gap lowering in the respective samples. Additional theoretical investigations, mostly based on Monte-Carlo methods, tried to understand the atomistic origin of this disorder induced band gap lowering. Here, we present theoretical results from first-principles calculations based on density functional theory for the disorder induced band gap lowering in kesterite Cu2ZnSnSe4 and Ag2ZnSnSe4, where the Cu–Zn and Ag–Zn disorder is modelled via a supercell approach and special quasirandom structures. Results of subsequent analyses of structural, electronic, and optical properties are discussed with respect to available experimental results, and will provide additional insight and knowledge towards the atomistic origin of the observed disorder induced band gap lowering in kesterite type materials. Y1 - 2024 U6 - https://doi.org/10.1088/1361-648X/ad52de SN - 0953-8984 VL - 36 IS - 37 PB - IOP Publishing ER - TY - JOUR A1 - Eigen, Lennart A1 - Wölfer, Jan A1 - Baum, Daniel A1 - Van Le, Mai-Lee A1 - Werner, Daniel A1 - Dean, Mason N. A1 - Nyakatura, John A. T1 - Comparative architecture of the tessellated boxfish (Ostracioidea) carapace JF - Communications Biology Y1 - 2024 U6 - https://doi.org/10.1038/s42003-024-07119-z VL - 7 ER - TY - JOUR A1 - Yang, Binru A1 - Knötel, David A1 - Ciecierska-Holmes, Jana A1 - Wölfer, Jan A1 - Chaumel, Júlia A1 - Zaslansky, Paul A1 - Baum, Daniel A1 - Fratzl, Peter A1 - Dean, Mason N. T1 - Growth of a tessellation: geometric rules for the development of stingray skeletal patterns JF - Advanced Science Y1 - 2024 U6 - https://doi.org/10.1002/advs.202407641 VL - 11 IS - 48 ER - TY - CHAP A1 - Lindner, Niels A1 - Masing, Berenike A1 - Liebchen, Christian T1 - Integrierte Baufahrplanoptimierung auf dem Netz der S-Bahn Berlin T2 - HEUREKA'24 - Optimierung in Verkehr und Transport N2 - Zur Instandhaltung von Eisenbahnnetzen sind regelmäßig Baumaßnahmen erforderlich. Diese erfordern stets Anpassungen der Fahrpläne. Um den Fahrgästen trotz der Baumaßnahme weiterhin einen möglichst großen Teil des Regelangebotes bieten zu können, bewegen sich die resultierenden Baufahrpläne insbesondere in Schnellbahnnetzen mit ihren dichten Zugfolgen häufig nahe der Kapazitätsgrenze der Infrastruktur. Etablierte Verfahren zur Taktfahrplanoptimierung können diesen Anforderungen nicht genügen, da in der Praxis Anpassungen von Laufwegen der Linien, sowie der Gleisbelegungen häufig Teil der realisierten Lösungen sind. Für diese Aufgabe haben die Autoren zuletzt ein Optimierungsmodell vorgestellt, welches diese Möglichkeiten ausschöpft. In dem vorliegenden Beitrag wird erstmalig dessen Anwendung auf ein unmittelbar der Praxis der Baufahrplanung entnommenes Beispiel aus dem Netz der Berliner S-Bahn im Detail beschrieben. Y1 - 2024 VL - 002/140 ER - TY - CHAP A1 - Lindner, Niels A1 - Masing, Berenike T1 - SAT-Generated Initial Solutions for Integrated Line Planning and Turn-Sensitive Periodic Timetabling with Track Choice T2 - hEART 2024: 12th Symposium of the European Association for Research in Transportation N2 - Periodic timetabling is a challenging planning task in public transport. As safety requirements are crucial, track allocation is indispensable for validating the practical feasibility of a railway timetable. For busy stations with limited capacities, this requires a detailed planning of turn-arounds. It is therefore desirable to integrate timetabling not only with track allocation, but also with vehicle scheduling and line planning. This is captured by the Integrated Line Planning and Turn-Sensitive Periodic Timetabling Problem with Track Choice, whose MIP formulation has been demonstrated to be effective for construction site railway rescheduling, as long as a good quality initial solution is available. In this paper, we discuss how to generate such a solution by extending the SAT formulation of the Periodic Event Scheduling Problem with track choice, track occupation, and minimum service frequency components. The SAT approach is superior to pure MIP on real-world instances of the S-Bahn Berlin network. KW - Periodic Timetabling KW - Railway Timetabling KW - Railway Track Allocation KW - Boolean Satisfiability Problem KW - Rescheduling KW - Line Planning Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-98066 UR - https://transp-or.epfl.ch/heart/2024/abstracts/hEART_2024_paper_3685.pdf ER - TY - GEN A1 - Yueksel-Erguen, Inci A1 - Litzel, Ida A1 - Peng, Hanqiu T1 - Integrating Large Citation Datasets N2 - This paper explores methods for building a comprehensive citation graph using big data techniques to evaluate scientific impact more accurately. Traditional citation metrics have limitations, and this work investigates merging large citation datasets to create a more accurate picture. Challenges of big data, like inconsistent data formats and lack of unique identifiers, are addressed through deduplication efforts, resulting in a streamlined and reliable merged dataset with over 119 million records and 1.4 billion citations. We demonstrate that merging large citation datasets builds a more accurate citation graph facilitating a more robust evaluation of scientific impact. T3 - ZIB-Report - 24-10 KW - big data preprocessing KW - data analytics KW - citation graphs Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-98033 SN - 1438-0064 ER - TY - GEN A1 - Löbel, Fabian A1 - Borndörfer, Ralf A1 - Weider, Steffen T1 - Electric Bus Scheduling with Non-Linear Charging, Power Grid Bottlenecks, and Dynamic Recharge Rates N2 - Public transport operators are gradually electrifying their bus fleets, predominantly with battery-powered drive trains. These buses commonly have to be scheduled to recharge in-service, which gives rise to a number of challenges. A major problem is that the relationship between charging time and replenished driving range is non-linear, which is often approximately modeled. We examine the associated approximation error and show how it can result in a gross over- or underestimation of the fleet size. Moreover, we demonstrate that commonly used piecewise linear underestimations of the charge curve do not result in an underestimation of the predicted charge states in electric vehicle scheduling and routing models. Furthermore, since power grid upgrades are currently not keeping up with an ever growing electricity demand, operators are introducing active charge management tools to dynamically adjust the charging speed depending on the amount of available energy. It is therefore imperative to extend electric bus scheduling models to account for these developments. We propose a novel mixed-integer programming formulation for the electric bus scheduling problem featuring an improved approximation of the non-linear battery charging behavior as well as dynamic recharge speeds to accommodate grid load limits. The idea is to linearly interpolate what we call the charge increment function, which is closely related to the derivative of the commonly used charge curve. This provides very good error control and integrates easily into integer programming models. We demonstrate the practical usefulness of our model on a diverse library of real-life instances. Y1 - 2024 ER - TY - CHAP A1 - Borndörfer, Ralf A1 - Löbel, Andreas A1 - Löbel, Fabian A1 - Weider, Steffen T1 - Solving the Electric Bus Scheduling Problem by an Integrated Flow and Set Partitioning Approach T2 - 24th Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2024) N2 - Attractive and cost-efficient public transport requires solving computationally difficult optimization problems from network design to crew rostering. While great progress has been made in many areas, new requirements to handle increasingly complex constraints are constantly coming up. One such challenge is a new type of resource constraints that are used to deal with the state-of-charge of battery-electric vehicles, which have limited driving ranges and need to be recharged in-service. Resource constrained vehicle scheduling problems can classically be modelled in terms of either a resource constrained (multi-commodity) flow problem or in terms of a path-based set partition problem. We demonstrate how a novel integrated version of both formulations can be leveraged to solve resource constrained vehicle scheduling with replenishment in general and the electric bus scheduling problem in particular by Lagrangian relaxation and the proximal bundle method. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0030-drops-211992 VL - 123 SP - 11:1 EP - 11:16 PB - Schloss Dagstuhl -- Leibniz-Zentrum für Informatik CY - Dagstuhl, Germany ER - TY - CHAP A1 - Attree, Nicholas A1 - Gutiérrez, Pedro A1 - Groussin, Olivier A1 - Bürger, Johanna A1 - Keller, Horst Uwe A1 - Kramer, Tobias A1 - Lasagni Manghi, Riccardo A1 - Läuter, Matthias A1 - Lemos, Pablo A1 - Markkanen, Johannes A1 - Marschall, Raphael A1 - Schuckart, Christian T1 - The Results of ISSI Team #547: Understanding the Activity of Comets Through 67P's Dynamics T2 - EPSC Abstracts N2 - Understanding cometary activity gives us an insight into the materials properties, and therefore formation and evolution processes of these relatively pristine protoplanetary objects. We will present the results of an International Space Science Institute project to investigate the phenomenon through the effects of the outgassing activity on the orbit and spin-state of comet 67P/Churymov-Gerasimenko, e.g. its non-gravitational dynamics. This International Team gathered experts in orbital dynamics and trajectory reconstruction together with thermophysical modellers and comet observationalists, in order to compare the available extractions of 67P’s non-gravitational acceleration (NGA) from its trajectory. The team then fitted a combination of the NGA, the non-gravitational torque (NGT), and the total water-outgassing rate with a thermophysical activity model. The results of this model will be presented. In particular, it was found that: non-gravitational forces and torques are driven by water sublimation from the nucleus; thermal inertia and self-heating have only minor effects; spatially uniform activity cannot explain 67P's non-gravitational dynamics; spatially uniform momentum transfer cannot explain 67P's non-gravitational dynamics; and different terrain types have different instantaneous responses to insolation. The implications of these findings for the modelling of cometary material and the variety of surface types seen on 67P will be discussed. Y1 - 2024 U6 - https://doi.org/10.5194/epsc2024-82 VL - 17 ER - TY - JOUR A1 - Attree, Nicholas A1 - Gutiérrez, Pedro A1 - Groussin, Olivier A1 - Bürger, Johanna A1 - Keller, Horst Uwe A1 - Kramer, Tobias A1 - LASAGNI MANGHI, RICCARDO A1 - Läuter, Matthias A1 - Lemos, Pablo A1 - Markkanen, Johannes A1 - Marschall, Raphael A1 - Schuckart, Christian T1 - Varying water activity and momentum transfer on comet 67P/Churyumov-Gerasimenko from its non-gravitational forces and torques JF - Astronomy and Astrophysics N2 - Aims. We investigate the ability of a simultaneous fitting of comet 67P/Churyumov-Gerasimenko’s non-gravitational forces, torques, and total water-outgassing rate, as observed by Rosetta, to constrain complex thermophysical models of cometary material. Methods. We extend the previous work of fitting geographically defined surface outgassing models to the Rosetta observations by testing the effects of a more detailed geomorphological mapping, the resolution of the shape-model used, self-heating by neighbouring facets on the shape-model, thermal inertia in the outgassing solution, and the variation in the momentum coupling between the gas and the nucleus. We also directly compare the non-gravitational acceleration curves available in the literature. Results. We correct an error in the calculation of pole-orientation in the previous paper. We find that, under the assumptions of the model, non-gravitational forces and torques are driven by water sublimation from the nucleus, thermal inertia and self-heating have only minor effects, spatially uniform activity cannot explain 67P’s non-gravitational dynamics, spatially uniform momentum transfer cannot explain 67P’s non-gravitational dynamics, and different terrain types have different instantaneous responses to insolation. Conclusions. Consolidated terrain facing south on 67P/Churyumov-Gerasimenko has a high outgassing flux, a steep response to insolation, and a large gas momentum transfer coefficient. Instead, that facing north behaves differently, producing little to no water outgassing, and with a lower momentum transfer efficiency. Dusty terrain also has a lower outgassing rate and momentum transfer efficiency, and either depletes its volatile component or is buried in fall-back as the comet approaches the Sun. Momentum transfer appears correlated with insolation, likely due to an increased enhancement in the gas temperature as the dust it flows through is heated. Y1 - 2024 U6 - https://doi.org/10.1051/0004-6361/202450728 VL - 690 SP - A82 ER - TY - CHAP A1 - Kramer, Tobias A1 - Läuter, Matthias T1 - Benchmarking the rotating jet model of cometary activity with the trajectory of comet 67P/Churyumov-Gerasimenko T2 - EPSC Abstracts N2 - An important tool to assess the composition and the spatial origin of cometary material is the analysis of its trajectory reflecting gravitational acceleration due to solar system bodies complemented by non-gravitational accelerations (NGA). Y1 - 2024 U6 - https://doi.org/10.5194/epsc2024-207 VL - 17 ER - TY - GEN A1 - Lindner, Niels A1 - Bartoszuk, Karolina A1 - Debgupta, Srinwanti A1 - Gering, Marie-Claire A1 - Muschner, Christoph A1 - Zittel, Janina T1 - Warm-starting modeling to generate alternatives for energy transition paths in the Berlin-Brandenburg area N2 - Energy system optimization models are key to investigate energy transition paths towards a decarbonized future. Since this approach comes with intrinsic uncertainties, it is insufficient to compute a single optimal solution assuming perfect foresight to provide a profound basis for decision makers. The paradigm of modeling to generate alternatives enables to explore the near-optimal solution space to a certain extent. However, large-scale energy models require a non-negligible computation time to be solved. We propose to use warm start methods to accelerate the process of finding close-to-optimal alternatives. In an extensive case study for the energy transition of the Berlin-Brandenburg area, we make use of the sector-coupled linear programming oemof-B3 model to analyze a scenario for the year 2050 with a resolution of one hour and 100% reduction of greenhouse gas emissions. We demonstrate that we can actually achieve a significant computational speedup. T3 - ZIB-Report - 24-08 KW - Energy System Optimization KW - Energy Transition KW - Modeling to Generate Alternatives Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-97835 SN - 1438-0064 ER - TY - GEN A1 - Riedmüller, Stephanie A1 - Rivetta, Fabian A1 - Zittel, Janina T1 - Long-Term Multi-Objective Optimization for Integrated Unit Commitment and Investment Planning for District Heating Networks N2 - The need to decarbonize the energy system has intensified the focus on district heating networks in urban and suburban areas. Therefore, exploring transformation pathways with reasonable trade-offs between economic viability and environmental goals became necessary. We introduce a network-flow-based model class integrating unit commitment and long-term investment planning for multi-energy systems. While the integration of unit commitment and investment planning has been applied to multi-energy systems, a formal introduction and suitability for the application of long-term portfolio planning of an energy provider on an urban scale has yet to be met. Based on mixed integer linear programming, the model bridges the gap between overly detailed industrial modeling tools not designed for computational efficiency at scale and rather abstract academic models. The formulation is tested on Berlin's district heating network. Hence, the challenge lies in a large number of variables and constraints and the coupling of time steps, for example, through investment decisions. A case study explores different solutions on the Pareto front defined by optimal trade-offs between minimizing costs and emissions through a lexicographic optimization approach. The resulting solution catalog can provide decision-makers valuable insights into feasible transformation pathways, highlighting distinctions between robust and target-dependent investments. T3 - ZIB-Report - 24-09 KW - multi-objective optimization KW - multi-energy systems KW - investment planning KW - unit commitment Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-97804 SN - 1438-0064 ER - TY - GEN A1 - Ebert, Patricia A1 - Masing, Berenike A1 - Lindner, Niels A1 - Gleixner, Ambros T1 - Sorting Criteria for Line-based Periodic Timetabling Heuristics N2 - It is well-known that optimal solutions are notoriously hard to find for the Periodic Event Scheduling Problem (PESP), which is the standard mathematical formulation to optimize periodic timetables in public transport. We consider a class of incremental heuristics that have been demonstrated to be effective by Lindner and Liebchen (2023), however, for only one fixed sorting strategy of lines along which a solution is constructed. Thus, in this paper, we examine a variety of sortings based on the number, weight, weighted span, and lower bound of arcs, and test for each setting various combinations of the driving, dwelling, and transfer arcs of lines. Additionally, we assess the impact on the incremental extension of the event-activity network by minimizing resp. maximizing a connectivity measure between subsets of lines. We compare our 27 sortings on the railway instances of the benchmarking library PESPlib within the ConcurrentPESP solver framework. We are able to find five new incumbent solutions, resulting in improvements of up to 2%. T3 - ZIB-Report - 24-07 KW - Public Transport KW - Timetabling KW - Periodic Event Scheduling Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-97826 SN - 1438-0064 ER - TY - JOUR A1 - Witzke, Joel A1 - Lößer, Ansgar A1 - Bountris, Vasilis A1 - Schintke, Florian A1 - Scheuermann, Björn T1 - Low-level I/O Monitoring for Scientific Workflows JF - CoRR Y1 - 2024 U6 - https://doi.org/10.48550/ARXIV.2408.00411 VL - abs/2408.00411 SP - 1 EP - 10 ER - TY - CHAP A1 - Witzke, Joel A1 - Lößer, Ansgar A1 - Bountris, Vasilis A1 - Schintke, Florian A1 - Scheuermann, Björn T1 - I/O of Scientific Workflows Monitored in Detail T2 - 20th IEEE International Conference on e-Science, e-Science 2024, Osaka, Japan, September 16-20, 2024 Y1 - 2024 U6 - https://doi.org/10.1109/E-SCIENCE62913.2024.10678728 N1 - Best Poster Award SP - 1 EP - 2 ER - TY - CHAP A1 - Bortoletto, Enrico A1 - van Lieshout, Rolf Nelson A1 - Masing, Berenike A1 - Lindner, Niels T1 - Periodic Event Scheduling with Flexible Infrastructure Assignment T2 - 24th Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2024) N2 - We present novel extensions of the Periodic Event Scheduling Problem (PESP) that integrate the assignment of activities to infrastructure elements. An application of this is railway timetabling, as station and platform capacities are limited and need to be taken into account. We show that an assignment of activities to platforms can always be made periodic, and that it can be beneficial to allow larger periods for the assignment than for the timetable. We present mixed-integer programming formulations for the general problem, as well as for the practically relevant case when multiple platforms can be considered equivalent, for which we present a bipartite matching approach. We finally test and compare these models on real-world instances. Y1 - 2024 U6 - https://doi.org/10.4230/OASIcs.ATMOS.2024.4 VL - 123 SP - 4:1 EP - 4:18 ER - TY - CHAP A1 - Prause, Felix A1 - Borndörfer, Ralf T1 - A Bayesian Rolling Horizon Approach for Rolling Stock Rotation Planning with Predictive Maintenance T2 - 24th Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2024) N2 - We consider the rolling stock rotation planning problem with predictive maintenance (RSRP-PdM), where a timetable given by a set of trips must be operated by a fleet of vehicles. Here, the health states of the vehicles are assumed to be random variables, and their maintenance schedule should be planned based on their predicted failure probabilities. Utilizing the Bayesian update step of the Kalman filter, we develop a rolling horizon approach for RSRP-PdM, in which the predicted health state distributions are updated as new data become available. This approach reduces the uncertainty of the health states and thus improves the decision-making basis for maintenance planning. To solve the instances, we employ a local neighborhood search, which is a modification of a heuristic for RSRP-PdM, and demonstrate its effectiveness. Using this solution algorithm, the presented approach is compared with the results of common maintenance strategies on test instances derived from real-world timetables. The obtained results show the benefits of the rolling horizon approach. Y1 - 2024 U6 - https://doi.org/10.4230/OASIcs.ATMOS.2024.13 VL - 123 SP - 13:1 EP - 13:19 ER - TY - CHAP A1 - Jäger, Klaus A1 - Burger, Sven A1 - Aeberhard, Urs A1 - Llado, Esther Alarcon A1 - Bläsi, Benedikt A1 - Ehrler, Bruno A1 - Favre, Wilfried A1 - Fejfar, Antonín A1 - Gageot, Tristan A1 - Gordon, Ivan A1 - Helmers, Henning A1 - Höhn, Oliver A1 - Isabella, Olindo A1 - Jošt, Marko A1 - Ledinský, Martin A1 - Mandal, Jyotirmoy A1 - Manley, Phillip A1 - Munoz, Delfina A1 - Lizcano, Juan Camilo Ortiz A1 - Paetzold, Ulrich W. A1 - Raman, Aaswath P. A1 - Sai, Hitoshi A1 - Saive, Rebecca A1 - Schmid, Martina A1 - Yablonovitch, Eli A1 - Becker, Christiane T1 - A Roadmap on Optics for Terawatt Scale Photovoltaics T2 - Advanced Photonics Congress 2024 Y1 - 2024 U6 - https://doi.org/10.1364/SELED.2024.STu2G.5 SP - STu2G.5 PB - Optica Publishing Group ER - TY - CHAP A1 - Binkowski, Felix A1 - Betz, Fridtjof A1 - Hammerschmidt, Martin A1 - Zschiedrich, Lin A1 - Burger, Sven T1 - Poles and Zeros in Resonant Nano-Photonic Systems T2 - 2024 Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR) Y1 - 2024 U6 - https://doi.org/10.1109/CLEO-PR60912.2024.10676837 ER - TY - JOUR A1 - Roy, Sutapa A1 - Höfling, Felix T1 - Critical surface adsorption of confined binary liquids with locally conserved mass and composition JF - Molecular Physics N2 - Close to a solid surface, the properties of a fluid deviate significantly from their bulk values. In this context, we study the surface adsorption profiles of a symmetric binary liquid confined to a slit pore by means of molecular dynamics simulations; the latter naturally entails that mass and concentration are locally conserved. Near a bulk consolute point, where the liquid exhibits a demixing transition with the local concentration as the order parameter, we determine the order parameter profiles and characterise the relevant critical scaling behaviour, in the regime of strong surface attraction, for a range of pore widths and temperatures. The obtained order parameter profiles decay monotonically near the surfaces, also in the presence of a pronounced layering in the number density. Overall, our results agree qualitatively with recent theoretical predictions from a mesoscopic field-theoretical approach for the canonical ensemble. Y1 - 2024 U6 - https://doi.org/10.1080/00268976.2024.2391998 VL - 122 IS - 21-22 SP - e2391998 ER - TY - JOUR A1 - Stengl, Steven-Marian A1 - Gelß, Patrick A1 - Klus, Stefan A1 - Pokutta, Sebastian T1 - Existence and uniqueness of solutions of the Koopman--von Neumann equation on bounded domains JF - Journal of Physics A: Mathematical and Theoretical Y1 - 2024 U6 - https://doi.org/10.1088/1751-8121/ad6f7d VL - 57 IS - 39 ER - TY - JOUR A1 - Böttcher, Julia A1 - Parczyk, Olaf A1 - Sgueglia, Amedeo A1 - Skokan, Jozef T1 - The square of a Hamilton cycle in randomly perturbed graphs JF - Random Structures & Algorithms Y1 - 2024 U6 - https://doi.org/10.1002/rsa.21215 VL - 65 IS - 2 SP - 342 EP - 386 ER - TY - JOUR A1 - Deza, Antoine A1 - Onn, Shmuel A1 - Pokutta, Sebastian A1 - Pournin, Lionel T1 - Kissing polytopes JF - SIAM Journal on Discrete Mathematics N2 - We investigate the following question: How close can two disjoint lattice polytopes contained in a fixed hypercube be? This question stems from various contexts where the minimal distance between such polytopes appears in complexity bounds of optimization algorithms. We provide nearly matching bounds on this distance and discuss its exact computation. We also give similar bounds for disjoint rational polytopes whose binary encoding length is prescribed. Y1 - 2024 U6 - https://doi.org/10.1137/24M1640859 VL - 38 IS - 4 ER - TY - CHAP A1 - Gossing, Anne A1 - Beckert, Andreas A1 - Fischer, Christoph A1 - Klenert, Nicolas A1 - Natarajan, Vijay A1 - Pacey, George A1 - Vogt, Thorwin A1 - Rautenhaus, Marc A1 - Baum, Daniel T1 - A Ridge-based Approach for Extraction and Visualization of 3D Atmospheric Fronts T2 - 2024 IEEE Visualization and Visual Analytics (VIS) N2 - An atmospheric front is an imaginary surface that separates two distinct air masses and is commonly defined as the warm-air side of a frontal zone with high gradients of atmospheric temperature and humidity. These fronts are a widely used conceptual model in meteorology, which are often encountered in the literature as two-dimensional (2D) front lines on surface analysis charts. This paper presents a method for computing three-dimensional (3D) atmospheric fronts as surfaces that is capable of extracting continuous and well-confined features suitable for 3D visual analysis, spatio-temporal tracking, and statistical analyses. Recently developed contour-based methods for 3D front extraction rely on computing the third derivative of a moist potential temperature field. Additionally, they require the field to be smoothed to obtain continuous large-scale structures. This paper demonstrates the feasibility of an alternative method to front extraction using ridge surface computation. The proposed method requires only the sec- ond derivative of the input field and produces accurate structures even from unsmoothed data. An application of the ridge-based method to a data set corresponding to Cyclone Friederike demonstrates its benefits and utility towards visual analysis of the full 3D structure of fronts. Y1 - 2024 U6 - https://doi.org/10.1109/VIS55277.2024.00043 SP - 176 EP - 180 ER - TY - GEN A1 - Sikorski, Alexander T1 - ISOKANN.jl N2 - Julia pacarkge implementing the ISOKANN algorithm for the computation of invariant subspaces of Koopman operators Y1 - 2024 U6 - https://doi.org/10.5281/zenodo.11519359 ER - TY - JOUR A1 - Weimann, Kuba A1 - Conrad, Tim T1 - FELRec: Efficient Handling of Item Cold-Start With Dynamic Representation Learning in Recommender Systems JF - International Journal of Data Science and Analytics Y1 - 2024 U6 - https://doi.org/10.1007/s41060-024-00635-5 IS - 2024 PB - Springer Nature ER - TY - JOUR A1 - Binkowski, Felix A1 - Burger, Sven A1 - Kewes, Günter T1 - A tiny Drude scatterer can accurately model a coherent emitter in nanophotonics JF - Nanophotonics Y1 - 2024 U6 - https://doi.org/10.1515/nanoph-2024-0170 VL - 13 SP - 4537 ER - TY - JOUR A1 - Roche, Léo J. A1 - Betz, Fridtjof A1 - Yang, Yuhui A1 - Limame, Imad A1 - Shih, Ching-Wen A1 - Burger, Sven A1 - Reitzenstein, Stephan T1 - Numerical Investigation of a Coupled Micropillar - Waveguide System for Integrated Quantum Photonic Circuits JF - Adv. Quantum Technol. Y1 - 2024 U6 - https://doi.org/10.1002/qute.202400195 VL - 7 SP - 2400195 ER - TY - JOUR A1 - Kameda, Takeru A1 - Saha, Daniel K. A1 - Ray, Sourav A1 - Togashi, Yuichi A1 - Asano, Katsura T1 - Protocol for calculating binding free energy of RNA:RNA interactions through molecular dynamics simulations using adaptive biasing force technique JF - STAR Protocols Y1 - 2024 U6 - https://doi.org/10.1016/j.xpro.2024.103223 VL - 5 IS - 3 PB - Elsevier BV ER - TY - CHAP A1 - Winkler, Ludwig A1 - Richter, Lorenz A1 - Opper, Manfred T1 - Bridging discrete and continuous state spaces: Exploring the Ehrenfest process in time-continuous diffusion models T2 - Proceedings of the 41st International Conference on Machine Learning N2 - Generative modeling via stochastic processes has led to remarkable empirical results as well as to recent advances in their theoretical understanding. In principle, both space and time of the processes can be discrete or continuous. In this work, we study time-continuous Markov jump processes on discrete state spaces and investigate their correspondence to state-continuous diffusion processes given by SDEs. In particular, we revisit the Ehrenfest process, which converges to an Ornstein-Uhlenbeck process in the infinite state space limit. Likewise, we can show that the time-reversal of the Ehrenfest process converges to the time-reversed Ornstein-Uhlenbeck process. This observation bridges discrete and continuous state spaces and allows to carry over methods from one to the respective other setting. Additionally, we suggest an algorithm for training the time-reversal of Markov jump processes which relies on conditional expectations and can thus be directly related to denoising score matching. We demonstrate our methods in multiple convincing numerical experiments. Y1 - 2024 UR - https://raw.githubusercontent.com/mlresearch/v235/main/assets/winkler24a/winkler24a.pdf VL - 235 SP - 53017 EP - 53038 ER - TY - JOUR A1 - Sun, Jingtong A1 - Berner, Julius A1 - Richter, Lorenz A1 - Zeinhofer, Marius A1 - Müller, Johannes A1 - Azizzadenesheli, Kamyar A1 - Anandkumar, Anima T1 - Dynamical Measure Transport and Neural PDE Solvers for Sampling N2 - The task of sampling from a probability density can be approached as transporting a tractable density function to the target, known as dynamical measure transport. In this work, we tackle it through a principled unified framework using deterministic or stochastic evolutions described by partial differential equations (PDEs). This framework incorporates prior trajectory-based sampling methods, such as diffusion models or Schrödinger bridges, without relying on the concept of time-reversals. Moreover, it allows us to propose novel numerical methods for solving the transport task and thus sampling from complicated targets without the need for the normalization constant or data samples. We employ physics-informed neural networks (PINNs) to approximate the respective PDE solutions, implying both conceptional and computational advantages. In particular, PINNs allow for simulation- and discretization-free optimization and can be trained very efficiently, leading to significantly better mode coverage in the sampling task compared to alternative methods. Moreover, they can readily be fine-tuned with Gauss-Newton methods to achieve high accuracy in sampling. Y1 - 2024 ER - TY - CHAP A1 - Vaitl, Lorenz A1 - Winkler, Ludwig A1 - Richter, Lorenz A1 - Kessel, Pan T1 - Fast and unified path gradient estimators for normalizing flows T2 - International Conference on Learning Representations 2024 N2 - Recent work shows that path gradient estimators for normalizing flows have lower variance compared to standard estimators for variational inference, resulting in improved training. However, they are often prohibitively more expensive from a computational point of view and cannot be applied to maximum likelihood train- ing in a scalable manner, which severely hinders their widespread adoption. In this work, we overcome these crucial limitations. Specifically, we propose a fast path gradient estimator which improves computational efficiency significantly and works for all normalizing flow architectures of practical relevance. We then show that this estimator can also be applied to maximum likelihood training for which it has a regularizing effect as it can take the form of a given target energy func- tion into account. We empirically establish its superior performance and reduced variance for several natural sciences applications. Y1 - 2024 UR - https://openreview.net/pdf?id=zlkXLb3wpF ER - TY - JOUR A1 - Richter, Lorenz A1 - Sallandt, Leon A1 - Nüsken, Nikolas T1 - From continuous-time formulations to discretization schemes: tensor trains and robust regression for BSDEs and parabolic PDEs JF - Journal of Machine Learning Research N2 - The numerical approximation of partial differential equations (PDEs) poses formidable challenges in high dimensions since classical grid-based methods suffer from the so-called curse of dimensionality. Recent attempts rely on a combination of Monte Carlo methods and variational formulations, using neural networks for function approximation. Extending previous work (Richter et al., 2021), we argue that tensor trains provide an appealing framework for parabolic PDEs: The combination of reformulations in terms of backward stochastic differential equations and regression-type methods holds the romise of leveraging latent low-rank structures, enabling both compression and efficient computation. Emphasizing a continuous-time viewpoint, we develop iterative schemes, which differ in terms of computational efficiency and robustness. We demonstrate both theoretically and numerically that our methods can achieve a favorable trade-off between accuracy and computational efficiency. While previous methods have been either accurate or fast, we have identified a novel numerical strategy that can often combine both of these aspects. Y1 - 2024 UR - https://www.jmlr.org/papers/volume25/23-0982/23-0982.pdf VL - 25 SP - 248 ER - TY - JOUR A1 - Schmitt, Kira A1 - Titschack, Jürgen A1 - Baum, Daniel T1 - CoDA: Interactive Segmentation and Morphological Analysis of Dendroid Structures Exemplified on Stony Cold-Water Corals N2 - Dendroid stony corals build highly complex colonies that develop from a single coral polyp sitting in a cup-like skeleton, called corallite, by asexual reproduction, resulting in a tree-like branching pattern of its skeleton. Despite their beauty and ecological importance as reef builders in tropical shallow-water reefs as well as in cold-water coral mounds in the deep ocean, systematic studies investigating the ontogenetic morphological development of such coral colonies are largely missing. One reason for this is the sheer number of corallites – up to several thousands in a single coral colony. Another limiting factor, especially for the analysis of dendroid cold-water corals, is the existence of many secondary joints in the ideally tree-like structure that make a reconstruction of the skeleton tree extremely tedious. Herein, we present CoDA, the Coral Dendroid structure Analyzer, a visual analytics suite that allows for the first time to investigate the ontogenetic morphological development of complex dendroid coral colonies, exemplified on three important framework-forming dendroid cold-water corals: Lophelia pertusa (Linnaeus, 1758), Madrepora oculata (Linnaeus, 1758), and Goniocorella dumosa (Alcock, 1902). Input to CoDA is an initial instance segmentation of the coral polyp cavities (calices), from which it estimates the skeleton tree of the colony and extracts classical morphological measurements and advanced shape features of the individual corallites. CoDA also works as a proofreading and error correction tool by helping to identify wrong parts in the skeleton tree and providing tools to quickly correct these errors. The final skeleton tree enables the derivation of additional information about the calices/corallite instances that otherwise could not be obtained, including their ontogenetic generation and branching patterns – the basis of a fully quantitative statistical analysis of the coral colony morphology. Part of CoDA is CoDA.Graph, a feature-rich link-and-brush user interface for visualizing the extracted features and 2D graph layouts of the skeleton tree, enabling the real-time exploration of complex coral colonies and their building blocks, the individual corallites and branches. In the future, we expect CoDA to greatly facilitate the analysis of large stony corals of different species and morphotypes, as well as other dendroid structures, enabling new insights into the influence of genetic and environmental factors on their ontogenetic morphological development. Y1 - 2024 ER - TY - GEN A1 - Villani, Paolo A1 - Weiser, Martin T1 - Adaptive Gaussian process regression for inverse problems. ALGORITMY 2024 N2 - This submission contains the code used for the proceedings paper for ALGORITMY 2024, concerning surrogate model-based inverse problems. Version 2 modified plot appearances and fixed some minor typos. Y1 - 2024 ER - TY - JOUR A1 - Boniface, Dolachai A1 - Straube, Arthur A1 - Tierno, Pietro T1 - Photocatalytic magnetic microgyroscopes with activity-tunable precessional dynamics JF - Nano Letters N2 - Magnetic nano/microrotors are passive elements that spin around an axis due to an external rotating field while remaining confined to a close plane. They have been used to date in different applications related to fluid mixing, drug delivery or biomedicine. Here we realize an active version of a magnetic microgyroscope which is simultaneously driven by a photo-activated catalytic reaction and a rotating magnetic field. We investigate the uplift dynamics of this colloidal spinner when it stands up and precesses around its long axis while self-propelling due to the light induced decomposition of hydrogen peroxide in water. By combining experiments with theory, we show that activity emerging from the cooperative action of phoretic and osmotic forces effectively increase the gravitational torque which counteracts the magnetic and viscous ones, and carefully measure its contribution. Y1 - 2024 U6 - https://doi.org/10.1021/acs.nanolett.4c03386 VL - 24 IS - 47 SP - 14950 EP - 14956 ER - TY - JOUR A1 - Straube, Arthur A1 - Höfling, Felix T1 - Memory effects in colloidal motion under confinement and driving JF - J. Phys. A: Math. Theor. N2 - The transport of individual particles in inhomogeneous environments is complex and exhibits non-Markovian responses. The latter may be quantified by a memory function within the framework of the linear generalised Langevin equation (GLE). Here, we exemplify the implications of steady driving on the memory function of a colloidal model system for Brownian motion in a corrugated potential landscape, specifically, for one-dimensional motion in a sinusoidal potential. To this end, we consider the overdamped limit of the GLE, which is facilitated by separating the memory function into a singular (Markovian) and a regular (non-Markovian) part. Relying on exact solutions for the investigated model, we show that the random force entering the GLE must display a bias far from equilibrium, which corroborates a recent general prediction. Based on data for the mean-square displacement (MSD) obtained from Brownian dynamics simulations, we estimate the memory function for different driving strengths and show that already moderate driving accelerates the decay of the memory function by several orders of magnitude in time. We find that the memory may persist on much longer timescales than expected from the convergence of the MSD to its long-time asymptote. Furthermore, the functional form of the memory function changes from a monotonic decay to a non-monotonic, damped oscillatory behaviour, which can be understood from a competition of confined motion and depinning. Our analysis of the simulation data further reveals a pronounced non-Gaussianity, which questions the Gaussian approximation of the random force entering the GLE. Y1 - 2024 U6 - https://doi.org/10.1088/1751-8121/ad5b2d SN - 1751-8113 VL - 57 SP - 295003 PB - IOP Publishing ER - TY - JOUR A1 - Andrés Arcones, Daniel A1 - Weiser, Martin A1 - Koutsourelakis, Faidon-Stelios A1 - Unger, Jörg F. T1 - Model bias identification for Bayesian calibration of stochastic digital twins of bridges JF - Applied Stochastic Models in Business and Industry N2 - Simulation-based digital twins must provide accurate, robust and reliable digital representations of their physical counterparts. Quantifying the uncertainty in their predictions plays, therefore, a key role in making better-informed decisions that impact the actual system. The update of the simulation model based on data must be then carefully implemented. When applied to complex standing structures such as bridges, discrepancies between the computational model and the real system appear as model bias, which hinders the trustworthiness of the digital twin and increases its uncertainty. Classical Bayesian updating approaches aiming to infer the model parameters often fail at compensating for such model bias, leading to overconfident and unreliable predictions. In this paper, two alternative model bias identification approaches are evaluated in the context of their applicability to digital twins of bridges. A modularized version of Kennedy and O'Hagan's approach and another one based on Orthogonal Gaussian Processes are compared with the classical Bayesian inference framework in a set of representative benchmarks. Additionally, two novel extensions are proposed for such models: the inclusion of noise-aware kernels and the introduction of additional variables not present in the computational model through the bias term. The integration of such approaches in the digital twin corrects the predictions, quantifies their uncertainty, estimates noise from unknown physical sources of error and provides further insight into the system by including additional pre-existing information without modifying the computational model. Y1 - 2024 U6 - https://doi.org/10.1002/asmb.2897 VL - 41 IS - 3 ER - TY - CHAP A1 - Villani, Paolo A1 - Unger, Jörg F. A1 - Weiser, Martin T1 - Adaptive Gaussian Process Regression for Bayesian inverse problems T2 - Proceedings of the Conference Algoritmy 2024 N2 - We introduce a novel adaptive Gaussian Process Regression (GPR) methodology for efficient construction of surrogate models for Bayesian inverse problems with expensive forward model evaluations. An adaptive design strategy focuses on optimizing both the positioning and simulation accuracy of training data in order to reduce the computational cost of simulating training data without compromising the fidelity of the posterior distributions of parameters. The method interleaves a goal-oriented active learning algorithm selecting evaluation points and tolerances based on the expected impact on the Kullback-Leibler divergence of surrogated and true posterior with a Markov Chain Monte Carlo sampling of the posterior. The performance benefit of the adaptive approach is demonstrated for two simple test problems. Y1 - 2024 SP - 214 EP - 224 ER - TY - CHAP A1 - Ghannam, Mohammed A1 - Mexi, Gioni A1 - Lam, Edward A1 - Gleixner, Ambros T1 - Branch and price for the length-constrained cycle partition problem T2 - Proceedings of INFORMS Optimization Society Conference Y1 - 2024 ER - TY - JOUR A1 - Bolusani, Suresh A1 - Besançon, Mathieu A1 - Gleixner, Ambros A1 - Berthold, Timo A1 - D'Ambrosio, Claudia A1 - Muñoz, Gonzalo A1 - Paat, Joseph A1 - Thomopulos, Dimitri T1 - The MIP workshop 2023 computational competition on reoptimization JF - Mathematical Programming Computation N2 - This paper describes the computational challenge developed for a computational competition held in 2023 for the 20th anniversary of the Mixed Integer Programming Workshop. The topic of this competition was reoptimization, also known as warm starting, of mixed integer linear optimization problems after slight changes to the input data for a common formulation. The challenge was to accelerate the proof of optimality of the modified instances by leveraging the information from the solving processes of previously solved instances, all while creating high-quality primal solutions. Specifically, we discuss the competition’s format, the creation of public and hidden datasets, and the evaluation criteria. Our goal is to establish a methodology for the generation of benchmark instances and an evaluation framework, along with benchmark datasets, to foster future research on reoptimization of mixed integer linear optimization problems. Y1 - 2024 U6 - https://doi.org/10.1007/s12532-024-00256-w VL - 16 SP - 255 EP - 266 ER - TY - JOUR A1 - Carderera, Alejandro A1 - Besançon, Mathieu A1 - Pokutta, Sebastian T1 - Scalable Frank-Wolfe on generalized self-concordant functions via simple steps JF - SIAM Journal on Optimization Y1 - 2024 U6 - https://doi.org/10.1137/23M1616789 VL - 34 IS - 3 ER - TY - CHAP A1 - Eifler, Leon A1 - Witzig, Jakob A1 - Gleixner, Ambros T1 - Branch and cut for partitioning a graph into a cycle of clusters T2 - Combinatorial Optimization. ISCO 2024 N2 - In this paper we study formulations and algorithms for the cycle clustering problem, a partitioning problem over the vertex set of a directed graph with nonnegative arc weights that is used to identify cyclic behavior in simulation data generated from nonreversible Markov state models. Here, in addition to partitioning the vertices into a set of coherent clusters, the resulting clusters must be ordered into a cycle such as to maximize the total net flow in the forward direction of the cycle. We provide a problem-specific binary programming formulation and compare it to a formulation based on the reformulation-linearization technique (RLT). We present theoretical results on the polytope associated with our custom formulation and develop primal heuristics and separation routines for both formulations. In computational experiments on simulation data from biology we find that branch and cut based on the problem-specific formulation outperforms the one based on RLT. Y1 - 2024 U6 - https://doi.org/10.1007/978-3-031-60924-4_8 VL - 14594 SP - 97 EP - 108 ER - TY - CHAP A1 - Pauls, Jan A1 - Zimmer, Max A1 - Kelly, Una M A1 - Schwartz, Martin A1 - Saatchi, Sassan A1 - Ciais, Philippe A1 - Pokutta, Sebastian A1 - Brandt, Martin A1 - Gieseke, Fabian T1 - Estimating canopy height at scale T2 - Proceedings of the 41st International Conference on Machine Learning N2 - We propose a framework for global-scale canopy height estimation based on satellite data. Our model leverages advanced data preprocessing techniques, resorts to a novel loss function designed to counter geolocation inaccuracies inherent in the ground-truth height measurements, and employs data from the Shuttle Radar Topography Mission to effectively filter out erroneous labels in mountainous regions, enhancing the reliability of our predictions in those areas. A comparison between predictions and ground-truth labels yields an MAE/RMSE of 2.43 / 4.73 (meters) overall and 4.45 / 6.72 (meters) for trees taller than five meters, which depicts a substantial improvement compared to existing global-scale products. The resulting height map as well as the underlying framework will facilitate and enhance ecological analyses at a global scale, including, but not limited to, large-scale forest and biomass monitoring. Y1 - 2024 UR - https://raw.githubusercontent.com/mlresearch/v235/main/assets/pauls24a/pauls24a.pdf VL - 235 SP - 39972 EP - 39988 ER - TY - CHAP A1 - Hendrych, Deborah A1 - Besançon, Mathieu A1 - Pokutta, Sebastian T1 - Solving the optimal experiment design problem with mixed-integer convex methods T2 - 22nd International Symposium on Experimental Algorithms (SEA 2024) N2 - We tackle the Optimal Experiment Design Problem, which consists of choosing experiments to run or observations to select from a finite set to estimate the parameters of a system. The objective is to maximize some measure of information gained about the system from the observations, leading to a convex integer optimization problem. We leverage Boscia.jl, a recent algorithmic framework, which is based on a nonlinear branch-and-bound algorithm with node relaxations solved to approximate optimality using Frank-Wolfe algorithms. One particular advantage of the method is its efficient utilization of the polytope formed by the original constraints which is preserved by the method, unlike alternative methods relying on epigraph-based formulations. We assess our method against both generic and specialized convex mixed-integer approaches. Computational results highlight the performance of our proposed method, especially on large and challenging instances. Y1 - 2024 U6 - https://doi.org/10.4230/LIPIcs.SEA.2024.16 VL - 301 SP - 16:1 EP - 16:22 ER - TY - CHAP A1 - Kiem, Aldo A1 - Pokutta, Sebastian A1 - Spiegel, Christoph T1 - Categorification of Flag Algebras T2 - Discrete Mathematics Days 2024 Y1 - 2024 U6 - https://doi.org/10.37536/TYSP5643 SP - 259 EP - 264 ER - TY - CHAP A1 - Kiem, Aldo A1 - Pokutta, Sebastian A1 - Spiegel, Christoph T1 - The Four-Color Ramsey Multiplicity of Triangles T2 - Discrete Mathematics Days 2024 Y1 - 2024 U6 - https://doi.org/10.37536/TYSP5643 SP - 13 EP - 18 ER - TY - JOUR A1 - Hahn-Klimroth, Max A1 - Parczyk, Olaf A1 - Person, Yury T1 - Minimum degree conditions for containing an r-regular r-connected spanning subgraph JF - European Journal of Combinatorics Y1 - 2024 U6 - https://doi.org/10.1016/j.ejc.2024.103940 VL - 118 SP - 103940 ER - TY - JOUR A1 - Mundinger, Konrad A1 - Pokutta, Sebastian A1 - Spiegel, Christoph A1 - Zimmer, Max T1 - Extending the Continuum of Six-Colorings JF - Geombinatorics Quarterly Y1 - 2024 VL - 34 IS - 1 SP - 20 EP - 29 ER - TY - CHAP A1 - Mundinger, Konrad A1 - Pokutta, Sebastian A1 - Spiegel, Christoph A1 - Zimmer, Max T1 - Extending the Continuum of Six-Colorings T2 - Discrete Mathematics Days 2024 Y1 - 2024 U6 - https://doi.org/10.37536/TYSP5643 SP - 178 EP - 183 ER - TY - CHAP A1 - Martínez-Rubio, David A1 - Roux, Christophe A1 - Pokutta, Sebastian T1 - Convergence and Trade-Offs in Riemannian Gradient Descent and Riemannian Proximal Point T2 - Proceedings of the 41st International Conference on Machine Learning N2 - In this work, we analyze two of the most fundamental algorithms in geodesically convex optimization: Riemannian gradient descent and (possibly inexact) Riemannian proximal point. We quantify their rates of convergence and produce different variants with several trade-offs. Crucially, we show the iterates naturally stay in a ball around an optimizer, of radius depending on the initial distance and, in some cases, on the curvature. Previous works simply assumed bounded iterates, resulting in rates that were not fully quantified. We also provide an implementable inexact proximal point algorithm and prove several new useful properties of Riemannian proximal methods: they work when positive curvature is present, the proximal operator does not move points away from any optimizer, and we quantify the smoothness of its induced Moreau envelope. Further, we explore beyond our theory with empirical tests. Y1 - 2024 UR - https://raw.githubusercontent.com/mlresearch/v235/main/assets/marti-nez-rubio24a/marti-nez-rubio24a.pdf VL - 235 SP - 34920 EP - 34948 ER - TY - JOUR A1 - Parczyk, Olaf A1 - Pokutta, Sebastian A1 - Spiegel, Christoph A1 - Szabó, Tibor T1 - New Ramsey multiplicity bounds and search heuristics JF - Foundations of Computational Mathematics Y1 - 2024 U6 - https://doi.org/10.1007/s10208-024-09675-6 ER - TY - JOUR A1 - Allen, Peter A1 - Pfenninger, Vincent A1 - Parczyk, Olaf T1 - Resilience for tight Hamiltonicity JF - Combinatorial Theory Y1 - 2024 U6 - https://doi.org/10.5070/C64163846 VL - 4 IS - 1 ER - TY - JOUR A1 - Vu-Han, Tu-Lan A1 - Schettino, Rodrigo Bermudez A1 - Weiß, Claudia A1 - Perka, Carsten A1 - Winkler, Tobias A1 - Sunkara, Vikram A1 - Pumberger, Matthias T1 - An interpretable data-driven prediction model to anticipate scoliosis in spinal muscular atrophy in the era of (gene-) therapies JF - Scientific Reports N2 - 5q-spinal muscular atrophy (SMA) is a neuromuscular disorder (NMD) that has become one of the first 5% treatable rare diseases. The efficacy of new SMA therapies is creating a dynamic SMA patient landscape, where disease progression and scoliosis development play a central role, however, remain difficult to anticipate. New approaches to anticipate disease progression and associated sequelae will be needed to continuously provide these patients the best standard of care. Here we developed an interpretable machine learning (ML) model that can function as an assistive tool in the anticipation of SMA-associated scoliosis based on disease progression markers. We collected longitudinal data from 86 genetically confirmed SMA patients. We selected six features routinely assessed over time to train a random forest classifier. The model achieved a mean accuracy of 0.77 (SD 0.2) and an average ROC AUC of 0.85 (SD 0.17). For class 1 ‘scoliosis’ the average precision was 0.84 (SD 0.11), recall 0.89 (SD 0.22), F1-score of 0.85 (SD 0.17), respectively. Our trained model could predict scoliosis using selected disease progression markers and was consistent with the radiological measurements. During post validation, the model could predict scoliosis in patients who were unseen during training. We also demonstrate that rare disease data sets can be wrangled to build predictive ML models. Interpretable ML models can function as assistive tools in a changing disease landscape and have the potential to democratize expertise that is otherwise clustered at specialized centers. Y1 - 2024 U6 - https://doi.org/10.1038/s41598-024-62720-w VL - 14 IS - 11838 ER - TY - GEN A1 - Hajarolasvadi, Noushin A1 - Baum, Daniel T1 - Data for Training the DeepOrientation Model: Simulated cryo-ET tomogram patches N2 - A major restriction to applying deep learning methods in cryo-electron tomography is the lack of annotated data. Many large learning-based models cannot be applied to these images due to the lack of adequate experimental ground truth. One appealing alternative solution to the time-consuming and expensive experimental data acquisition and annotation is the generation of simulated cryo-ET images. In this context, we exploit a public cryo-ET simulator called PolNet to generate three datasets of two macromolecular structures, namely the ribosomal complex 4v4r and Thermoplasma acidophilum 20S proteasome, 3j9i. We select these two specific particles to test whether our models work for macromolecular structures with and without rotational symmetry. The three datasets contain 50, 150, and 450 tomograms with a voxel size of 10 ̊A, respectively. Here, we publish patches of size 40 × 40 × 40 extracted from the medium-sized dataset with 26,703 samples of 4v4r and 40,671 samples of 3j9i. The original tomograms from which the samples were extracted are of size 500 × 500 × 250. Finally, it should be noted that the currently published test dataset is employed for reporting the results of our paper titled ”DeepOrientation: Deep Orientation Estimation of Macromolecules in Cryo-electron tomography” paper. Y1 - 2024 U6 - https://doi.org/10.12752/9686 ER - TY - JOUR A1 - Siqueira Rodrigues, Lucas A1 - Schmidt, Timo Torsten A1 - Israel, Johann Habakuk A1 - Nyakatura, John A1 - Zachow, Stefan A1 - Kosch, Thomas T1 - Comparing the Effects of Visual, Haptic, and Visuohaptic Encoding on Memory Retention of Digital Objects in Virtual Reality JF - NordiCHI '24: Proceedings of the 13th Nordic Conference on Human-Computer Interaction N2 - Although Virtual Reality (VR) has undoubtedly improved human interaction with 3D data, users still face difficulties retaining important details of complex digital objects in preparation for physical tasks. To address this issue, we evaluated the potential of visuohaptic integration to improve the memorability of virtual objects in immersive visualizations. In a user study (N=20), participants performed a delayed match-to-sample task where they memorized stimuli of visual, haptic, or visuohaptic encoding conditions. We assessed performance differences between the conditions through error rates and response time. We found that visuohaptic encoding significantly improved memorization accuracy compared to unimodal visual and haptic conditions. Our analysis indicates that integrating haptics into immersive visualizations enhances the memorability of digital objects. We discuss its implications for the optimal encoding design in VR applications that assist professionals who need to memorize and recall virtual objects in their daily work. Y1 - 2024 U6 - https://doi.org/10.1145/3679318.3685349 SP - 1 EP - 13 ER -