@inproceedings{5822, author = {{Gaspers, Daniel and Knorr, Christoph and Nickchen, Tobias and Nickchen, Daniel and Mertsching, Barbel and Mohamed, Mahmoud A.}}, booktitle = {{2018 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR)}}, isbn = {{9781538655726}}, publisher = {{IEEE}}, title = {{{Real-time Graph-Based 3D Reconstruction of Sparse Feature Environments for Mobile Robot Applications}}}, doi = {{10.1109/ssrr.2018.8468658}}, year = {{2018}}, } @inproceedings{8750, abstract = {{In this article we propose a descent method for equality and inequality constrained multiobjective optimization problems (MOPs) which generalizes the steepest descent method for unconstrained MOPs by Fliege and Svaiter to constrained problems by using two active set strategies. Under some regularity assumptions on the problem, we show that accumulation points of our descent method satisfy a necessary condition for local Pareto optimality. Finally, we show the typical behavior of our method in a numerical example.}}, author = {{Gebken, Bennet and Peitz, Sebastian and Dellnitz, Michael}}, booktitle = {{Numerical and Evolutionary Optimization – NEO 2017}}, isbn = {{9783319961033}}, issn = {{1860-949X}}, title = {{{A Descent Method for Equality and Inequality Constrained Multiobjective Optimization Problems}}}, doi = {{10.1007/978-3-319-96104-0_2}}, year = {{2018}}, } @article{8751, abstract = {{Multiobjective optimization plays an increasingly important role in modern applications, where several criteria are often of equal importance. The task in multiobjective optimization and multiobjective optimal control is therefore to compute the set of optimal compromises (the Pareto set) between the conflicting objectives. The advances in algorithms and the increasing interest in Pareto-optimal solutions have led to a wide range of new applications related to optimal and feedback control, which results in new challenges such as expensive models or real-time applicability. Since the Pareto set generally consists of an infinite number of solutions, the computational effort can quickly become challenging, which is particularly problematic when the objectives are costly to evaluate or when a solution has to be presented very quickly. This article gives an overview of recent developments in accelerating multiobjective optimal control for complex problems where either PDE constraints are present or where a feedback behavior has to be achieved. In the first case, surrogate models yield significant speed-ups. Besides classical meta-modeling techniques for multiobjective optimization, a promising alternative for control problems is to introduce a surrogate model for the system dynamics. In the case of real-time requirements, various promising model predictive control approaches have been proposed, using either fast online solvers or offline-online decomposition. We also briefly comment on dimension reduction in many-objective optimization problems as another technique for reducing the numerical effort.}}, author = {{Peitz, Sebastian and Dellnitz, Michael}}, issn = {{2297-8747}}, journal = {{Mathematical and Computational Applications}}, number = {{2}}, title = {{{A Survey of Recent Trends in Multiobjective Optimal Control—Surrogate Models, Feedback Control and Objective Reduction}}}, doi = {{10.3390/mca23020030}}, volume = {{23}}, year = {{2018}}, } @inbook{8754, abstract = {{In this chapter, we combine a global, derivative-free subdivision algorithm for multiobjective optimization problems with a posteriori error estimates for reduced-order models based on Proper Orthogonal Decomposition in order to efficiently solve multiobjective optimization problems governed by partial differential equations. An error bound for a semilinear heat equation is developed in such a way that the errors in the conflicting objectives can be estimated individually. The resulting algorithm constructs a library of locally valid reduced-order models online using a Greedy (worst-first) search. Using this approach, the number of evaluations of the full-order model can be reduced by a factor of more than 1000.}}, author = {{Beermann, Dennis and Dellnitz, Michael and Peitz, Sebastian and Volkwein, Stefan}}, booktitle = {{Reduced-Order Modeling (ROM) for Simulation and Optimization}}, isbn = {{9783319753188}}, pages = {{47--72}}, title = {{{Set-Oriented Multiobjective Optimal Control of PDEs Using Proper Orthogonal Decomposition}}}, doi = {{10.1007/978-3-319-75319-5_3}}, year = {{2018}}, } @inproceedings{9999, abstract = {{Ultrasonic wire bonding is an indispensable process in the industrial manufacturing of semiconductor devices. Copper wire is increasingly replacing the well-established aluminium wire because of its superior electrical, thermal and mechanical properties. Copper wire processes differ significantly from aluminium processes and are more sensitive to disturbances, which reduces the range of parameter values suitable for a stable process. Disturbances can be compensated by an adaption of process parameters, but finding suitable parameters manually is difficult and time-consuming. This paper presents a physical model of the ultrasonic wire bonding process including the friction contact between tool and wire. This model yields novel insights into the process. A prototype of a multi-objective optimizing bonding machine (MOBM) is presented. It uses multi-objective optimization, based on the complete process model, to automatically select the best operating point as a compromise of concurrent objectives.}}, author = {{Unger, Andreas and Hunstig, Matthias and Meyer, Tobias and Brökelmann, Michael and Sextro, Walter}}, booktitle = {{In Proceedings of IMAPS 2018 – 51st Symposium on Microelectronics, Pasadena, CA, 2018}}, keywords = {{wire bonding, multi-objective optimization, process model, copper wire, self-optimization}}, title = {{{Intelligent Production of Wire Bonds using Multi-Objective Optimization – Insights, Opportunities and Challenges}}}, doi = {{10.4071/2380-4505-2018.1.000572}}, volume = {{Vol. 2018, No. 1, pp. 000572-000577.}}, year = {{2018}}, } @inproceedings{3930, author = {{Brassat, Katharina and Taube, A. and Kool, Daniel and Tasche, L. and Hoyer, K.P. and Schaper, Mirko and Lindner, Jörg}}, location = {{Warsaw, Poland}}, title = {{{Ti-6Al-4V alloy: 3D printing of lightweight implants and nanopatterning by self-assembly}}}, year = {{2018}}, } @article{669, abstract = {{We study a new class of games which generalizes congestion games andits bottleneck variant. We introduce congestion games with mixed objectives to modelnetwork scenarios in which players seek to optimize for latency and bandwidths alike.We characterize the (non-)existence of pure Nash equilibria (PNE), the convergenceof improvement dynamics, the quality of equilibria and show the complexity of thedecision problem. For games that do not possess PNE we give bounds on the approx-imation ratio of approximate pure Nash equilibria.}}, author = {{Feldotto, Matthias and Leder, Lennart and Skopalik, Alexander}}, issn = {{1382-6905}}, journal = {{Journal of Combinatorial Optimization}}, number = {{4}}, pages = {{1145--1167}}, publisher = {{Springer Nature}}, title = {{{Congestion games with mixed objectives}}}, doi = {{10.1007/s10878-017-0189-y}}, volume = {{36}}, year = {{2018}}, } @inproceedings{6970, abstract = {{Dynamic allocation of resources is a key feature in network function virtualization (NFV), enabling flexible adjustment of slices and contained network services to ever-changing service demands. Considering resource allocation across the entire network, many authors have proposed approaches to optimize the placement and chaining of virtual network function (VNF) instances and the allocation of resources to these VNF instances. In doing so, various optimization objectives are conceivable, e.g., minimizing certain required resources or the end-to-end delay of the placed services. In this paper, we investigate the relationship between four typical optimization objectives when coordinating the placement and resource allocation of chained VNF instances. We observe an interesting trade-off between minimizing the overhead of starting/stopping VNF instances and all other objectives when adapting to changed service demands.}}, author = {{Schneider, Stefan Balthasar and Dräxler, Sevil and Karl, Holger}}, booktitle = {{IEEE Global Communications Conference (GLOBECOM 2018)}}, location = {{Abu Dhabi, UAE}}, publisher = {{IEEE}}, title = {{{Trade-offs in Dynamic Resource Allocation in Network Function Virtualization}}}, year = {{2018}}, } @inproceedings{16425, abstract = {{In recent years, OpenCL has been increasingly adopted as it enables software programmers to harness the performance and power efficiency of FPGAs. Despite simplifying the FPGA programming challenge, achieving high performance and energy efficiency with OpenCL is still a difficult task. In order to further contribute to the advance of the OpenCL usage for FPGAs, we utilize a realistic application scenario as our case study: the AutoDock molecular docking software. While OpenCL has proven its effectiveness in accelerating molecular docking on GPUs, for FPGA-based AutoDock accelerators it struggles with difficult design patterns. Besides complex multiple-producers to single-consumer datapaths, these include time-intensive loops with variable runtimes. Therefore, this work presents the design and optimization steps for implementing AutoDock in OpenCL targeting an Arria-10 FPGA, as well as a corresponding execution runtime and energy-efficiency evaluation. Applying these techniques improved the performance of the initial OpenCL implementation for FPGAs by three orders of magnitude, with the final version of the code now yielding speed-ups of up to ~2.7x, and energy-efficiency gains of up to ~1.8x over the original serial AutoDock version executing on a current-generation CPU.}}, author = {{Solis-Vasquez, Leonardo and Koch, Andreas}}, booktitle = {{FSP Workshop 2018; Fifth International Workshop on FPGAs for Software Programmers}}, keywords = {{pc2-harp-ressources}}, pages = {{1--10}}, title = {{{A Case Study in Using OpenCL on FPGAs: Creating an Open-Source Accelerator of the AutoDock Molecular Docking Software}}}, year = {{2018}}, } @inproceedings{1181, abstract = {{The main idea in On-The-Fly Computing is to automatically compose existing software services according to the wishes of end-users. However, since user requirements are often ambiguous, vague and incomplete, the selection and composition of suitable software services is a challanging task. In this paper, we present our current approach to improve requirement descriptions before they are used for software composition. This procedure is fully automated, but also has limitations, for example, if necessary information is missing. In addition, and in response to the limitations, we provide insights into our above-mentioned current work that combines the existing optimization approach with a chatbot solution.}}, author = {{Bäumer, Frederik Simon and Geierhos, Michaela}}, booktitle = {{Joint Proceedings of REFSQ-2018 Workshops, Doctoral Symposium, Live Studies Track, and Poster Track co-located with the 23rd International Conference on Requirements Engineering: Foundation for Software Quality (REFSQ 2018)}}, editor = {{Schmid, Klaus and Spoletini, Paola and Ben Charrada, Eya and Chisik, Yoram and Dalpiaz, Fabiano and Ferrari, Alessio and Forbrig, Peter and Franch, Xavier and Kirikova, Marite and Madhavji, Nazim and Palomares, Cristina and Ralyté, Jolita and Sabetzadeh, Mehrdad and Sawyer, Pete and van der Linden, Dirk and Zamansky, Anna}}, issn = {{1613-0073}}, location = {{Utrecht, The Netherlands}}, publisher = {{CEUR-WS.org}}, title = {{{How to Deal with Inaccurate Service Requirements? Insights in Our Current Approach and New Ideas}}}, volume = {{2075}}, year = {{2018}}, } @inproceedings{15585, author = {{Bednarik, Roman and Schulte, Carsten and Budde, Lea and Heinemann, Birte and Vrzakova, Hana}}, booktitle = {{Proceedings of the 18th Koli Calling International Conference on Computing Education Research, Koli, Finland, November 22-25, 2018}}, pages = {{2:1--2:8}}, title = {{{Eye-movement Modeling Examples in Source Code Comprehension: A Classroom Study}}}, doi = {{10.1145/3279720.3279722}}, year = {{2018}}, } @inbook{14856, author = {{Hallmann, Corinna and Burmeister, Sascha Christian and Wissing, Michaela and Suhl, Leena}}, booktitle = {{Communications in Computer and Information Science}}, isbn = {{9783319962702}}, issn = {{1865-0929}}, title = {{{Heuristics and Simulation for Water Tank Optimization}}}, doi = {{10.1007/978-3-319-96271-9_5}}, year = {{2018}}, } @inproceedings{16034, author = {{Camberg, Alan Adam and Tröster, Thomas}}, booktitle = {{HYBRID - MATERIALS AND STRUCTURES 2018 - PROCEEDINGS}}, isbn = {{978-3-88355-417-4}}, location = {{Bremen}}, publisher = {{DGM - Deutsche Gesellschaft für Materialkunde e.V.}}, title = {{{Optimization-based material design of tailored stacked hybrids for further improvement in lightweight car body structures}}}, year = {{2018}}, } @unpublished{16293, abstract = {{Kernel transfer operators, which can be regarded as approximations of transfer operators such as the Perron-Frobenius or Koopman operator in reproducing kernel Hilbert spaces, are defined in terms of covariance and cross-covariance operators and have been shown to be closely related to the conditional mean embedding framework developed by the machine learning community. The goal of this paper is to show how the dominant eigenfunctions of these operators in combination with gradient-based optimization techniques can be used to detect long-lived coherent patterns in high-dimensional time-series data. The results will be illustrated using video data and a fluid flow example.}}, author = {{Klus, Stefan and Peitz, Sebastian and Schuster, Ingmar}}, booktitle = {{arXiv:1805.10118}}, title = {{{Analyzing high-dimensional time-series data using kernel transfer operator eigenfunctions}}}, year = {{2018}}, } @article{1369, abstract = {{In budget games, players compete over resources with finite budgets. For every resource, a player has a specific demand and as a strategy, he chooses a subset of resources. If the total demand on a resource does not exceed its budget, the utility of each player who chose that resource equals his demand. Otherwise, the budget is shared proportionally. In the general case, pure Nash equilibria (NE) do not exist for such games. In this paper, we consider the natural classes of singleton and matroid budget games with additional constraints and show that for each, pure NE can be guaranteed. In addition, we introduce a lexicographical potential function to prove that every matroid budget game has an approximate pure NE which depends on the largest ratio between the different demands of each individual player.}}, author = {{Drees, Maximilian and Feldotto, Matthias and Riechers, Sören and Skopalik, Alexander}}, issn = {{1382-6905}}, journal = {{Journal of Combinatorial Optimization}}, publisher = {{Springer Nature}}, title = {{{Pure Nash equilibria in restricted budget games}}}, doi = {{10.1007/s10878-018-0269-7}}, year = {{2018}}, } @article{8753, abstract = {{In a wide range of applications it is desirable to optimally control a dynamical system with respect to concurrent, potentially competing goals. This gives rise to a multiobjective optimal control problem where, instead of computing a single optimal solution, the set of optimal compromises, the so-called Pareto set, has to be approximated. When the problem under consideration is described by a partial differential equation (PDE), as is the case for fluid flow, the computational cost rapidly increases and makes its direct treatment infeasible. Reduced order modeling is a very popular method to reduce the computational cost, in particular in a multi query context such as uncertainty quantification, parameter estimation or optimization. In this article, we show how to combine reduced order modeling and multiobjective optimal control techniques in order to efficiently solve multiobjective optimal control problems constrained by PDEs. We consider a global, derivative free optimization method as well as a local, gradient-based approach for which the optimality system is derived in two different ways. The methods are compared with regard to the solution quality as well as the computational effort and they are illustrated using the example of the flow around a cylinder and a backward-facing-step channel flow.}}, author = {{Peitz, Sebastian and Ober-Blöbaum, Sina and Dellnitz, Michael}}, issn = {{0167-8019}}, journal = {{Acta Applicandae Mathematicae}}, number = {{1}}, pages = {{171–199}}, title = {{{Multiobjective Optimal Control Methods for the Navier-Stokes Equations Using Reduced Order Modeling}}}, doi = {{10.1007/s10440-018-0209-7}}, volume = {{161}}, year = {{2018}}, } @article{27027, author = {{Bühlmeier, Judith and Harris, Carla and Koletzko, Sibylle and Lehmann, Irina and Bauer, Carl-Peter and Schikowski, Tamara and von Berg, Andrea and Berdel, Dietrich and Heinrich, Joachim and Hebebrand, Johannes and Föcker, Manuel and Standl, Marie and Libuda, Lars}}, issn = {{2072-6643}}, journal = {{Nutrients}}, title = {{{Dietary Acid Load and Mental Health Outcomes in Children and Adolescents: Results from the GINIplus and LISA Birth Cohort Studies}}}, doi = {{10.3390/nu10050582}}, year = {{2018}}, } @inproceedings{5831, abstract = {{Many websites offer links to social media sites for convenient content sharing. Unfortunately, those sharing capabilities are quite restricted and it is seldom possible to share content with other services, like those provided by a user's favorite applications or smart devices. In this paper, we present Semantic Data Mediator (SDM) --- a flexible middleware linking a vast number of services to millions of websites. Based on reusable repositories of service descriptions defined by the crowd, users can easily fill a personal registry with their favorite services, which can then be linked to websites by SDM. For this, SDM leverages semantic data, which is already available on millions of websites due to search engine optimization. Further support for our approach from website or service developers is not required. To enable the use of a broad range of services, data conversion services are automatically composed by SDM to transform data according to the needs of the different services. In addition to linking web services, various service adapters allow services of applications and smart devices to be linked as well. We have fully implemented our approach and present a real-world case study demonstrating its feasibility and usefulness.}}, author = {{Wolters, Dennis and Heindorf, Stefan and Kirchhoff, Jonas and Engels, Gregor}}, booktitle = {{Service-Oriented Computing -- ICSOC 2017 Workshops}}, editor = {{Braubach, Lars and Murillo, Juan M. and Kaviani, Nima and Lama, Manuel and Burgueño, Loli and Moha, Naouel and Oriol, Marc}}, isbn = {{978-3-319-91764-1}}, pages = {{388--392}}, publisher = {{Springer International Publishing}}, title = {{{Semantic Data Mediator: Linking Services to Websites}}}, doi = {{10.1007/978-3-319-91764-1_36}}, year = {{2018}}, } @techreport{36411, author = {{Becker, Rieke and Heidgen, Michael and Lauert, Markus and Witschel, Verena}}, title = {{{Tagungsbericht: Kulturen der Moral – Moral Cultures. Internationale und interdisziplinäre Tagung in Kooperation mit der DGEJ vom 19. bis 22. September 2018 an der Universität Paderborn.}}}, year = {{2018}}, } @inproceedings{46350, abstract = {{The ubiquity of WiFi access points and the sharp increase in WiFi-enabled devices carried by humans have paved the way for WiFi-based indoor positioning and location analysis. Locating people in indoor environments has numerous applications in robotics, crowd control, indoor facility optimization, and automated environment mapping. However, existing WiFi-based positioning systems suffer from two major problems: (1) their accuracy and precision is limited due to inherent noise induced by indoor obstacles, and (2) they only occasionally provide location estimates, namely when a WiFi-equipped device emits a signal. To mitigate these two issues, we propose a novel Gaussian process (GP) model for WiFi signal strength measurements. It allows for simultaneous smoothing (increasing accuracy and precision of estimators) and interpolation (enabling continuous sampling of location estimates). Furthermore, simple and efficient smoothing methods for location estimates are introduced to improve localization performance in real-time settings. Experiments are conducted on two data sets from a large real-world commercial indoor retail environment. Results demonstrate that our approach provides significant improvements in terms of precision and accuracy with respect to unfiltered data. Ultimately, the GP model realizes continuous location sampling with consistently high quality location estimates.}}, author = {{van Engelen, J.E. and van Lier, J.J. and Takes, F.W. and Trautmann, Heike}}, booktitle = {{Proceedings of the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Database (ECML/PKDD)}}, pages = {{524–540}}, publisher = {{Springer}}, title = {{{Accurate WiFi based indoor positioning with continuous location sampling}}}, year = {{2018}}, }