@inbook{14890, author = {{Kuhlemann, Stefan and Sellmann, Meinolf and Tierney, Kevin}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783030300470}}, issn = {{0302-9743}}, title = {{{Exploiting Counterfactuals for Scalable Stochastic Optimization}}}, doi = {{10.1007/978-3-030-30048-7_40}}, year = {{2019}}, } @techreport{14902, author = {{Mair, Christina and Scheffler, Wolfram and Senger, Isabell and Sureth-Sloane, Caren}}, title = {{{Analyse der Veränderung der zwischenstaatlichen Gewinnaufteilung bei Einführung einer standardisierten Gewinnverteilungsmethode am Beispiel des Einsatzes von 3D-Druckern}}}, volume = {{42}}, year = {{2019}}, } @unpublished{16341, abstract = {{We present a technique for rendering highly complex 3D scenes in real-time by generating uniformly distributed points on the scene's visible surfaces. The technique is applicable to a wide range of scene types, like scenes directly based on complex and detailed CAD data consisting of billions of polygons (in contrast to scenes handcrafted solely for visualization). This allows to visualize such scenes smoothly even in VR on a HMD with good image quality, while maintaining the necessary frame-rates. In contrast to other point based rendering methods, we place points in an approximated blue noise distribution only on visible surfaces and store them in a highly GPU efficient data structure, allowing to progressively refine the number of rendered points to maximize the image quality for a given target frame rate. Our evaluation shows that scenes consisting of a high amount of polygons can be rendered with interactive frame rates with good visual quality on standard hardware.}}, author = {{Brandt, Sascha and Jähn, Claudius and Fischer, Matthias and Meyer auf der Heide, Friedhelm}}, booktitle = {{arXiv:1904.08225}}, title = {{{Rendering of Complex Heterogenous Scenes using Progressive Blue Surfels}}}, year = {{2019}}, } @inproceedings{13123, abstract = {{Given the recent development in embedded devices, wireless senor nodes are no longer limited to data collection but they can also do processing (e.g., smartphones). Accordingly, new types of applications take an advantage of the processing and flexibility provided by the wireless network. A common property between these applications is that the processing is not running on only one single node, but it is broken-down into smaller tasks that can run over multiple nodes, i.e., exploiting the in-network processing. We study a special variant of in-network processing, where the application is given by a graph; the processing tasks have predefined connections to be executed in a predefined sequence. The problem of embedding an application graph into a network is commonly known as Virtual Network Embedding (VNE). In this paper, we present a Genetic Algorithm (GA) solution to solve this wireless VNE problem, where we take into account the interference and multi-cast properties. We show that the GA has a good performance and fast execution compared to the optimization problem.}}, author = {{Afifi, Haitham and Horbach, Konrad and Karl, Holger}}, booktitle = {{2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) (WiMob 2019)}}, title = {{{A Genetic Algorithm Framework for Solving Wireless Virtual Network Embedding}}}, year = {{2019}}, } @inproceedings{13250, author = {{Ansótegui, Carlos and Heymann, Britta and Pon, Josep and Sellmann, Meinolf and Tierney, Kevin}}, booktitle = {{Learning and Intelligent Optimization}}, isbn = {{978-3-030-05347-5}}, pages = {{309--325}}, publisher = {{Springer International Publishing}}, title = {{{Hyper-Reactive Tabu Search for MaxSAT}}}, doi = {{10.1007/978-3-030-05348-2_27}}, year = {{2019}}, } @article{13434, author = {{Mäck, Markus and Caylak, Ismail and Edler, Philipp and Freitag, Steffen and Hanss, Michael and Mahnken, Rolf and Meschke, Günther and Penner, Eduard}}, issn = {{0936-7195}}, journal = {{GAMM-Mitteilungen}}, title = {{{"Optimization with constraints considering polymorphic uncertainties"}}}, doi = {{10.1002/gamm.201900005}}, year = {{2019}}, } @inproceedings{13442, author = {{Manavi, Seyed Alborz and Kenig, Eugeny}}, booktitle = {{Computer Aided Chemical Engineering}}, isbn = {{9780128186343}}, issn = {{1570-7946}}, publisher = {{29th European Symposium on Computer Aided Process Engineering}}, title = {{{Numerical Simulation of Forced Convection in a Microchannel with Realistic Roughness of 3D Printed Surface}}}, doi = {{10.1016/b978-0-12-818634-3.50138-7}}, year = {{2019}}, } @inproceedings{13443, abstract = {{This work considers the problem of control and resource allocation in networked systems. To this end, we present DIRA a Deep reinforcement learning based Iterative Resource Allocation algorithm, which is scalable and control-aware. Our algorithm is tailored towards large-scale problems where control and scheduling need to act jointly to optimize performance. DIRA can be used to schedule general time-domain optimization based controllers. In the present work, we focus on control designs based on suitably adapted linear quadratic regulators. We apply our algorithm to networked systems with correlated fading communication channels. Our simulations show that DIRA scales well to large scheduling problems.}}, author = {{Redder, Adrian and Ramaswamy, Arunselvan and Quevedo, Daniel}}, booktitle = {{Proceedings of the 8th IFAC Workshop on Distributed Estimation and Control in Networked Systems}}, keywords = {{Networked control systems, deep reinforcement learning, large-scale systems, resource scheduling, stochastic control}}, location = {{Chicago, USA}}, title = {{{Deep reinforcement learning for scheduling in large-scale networked control systems}}}, year = {{2019}}, } @inproceedings{10093, author = {{Beyer, Dirk and Jakobs, Marie-Christine and Lemberger, Thomas and Wehrheim, Heike}}, booktitle = {{Software Engineering and Software Management (SE/SWM 2019), Stuttgart, Germany, February 18-22, 2019}}, editor = {{Becker, Steffen and Bogicevic, Ivan and Herzwurm, Georg and Wagner, Stefan}}, pages = {{151----152}}, publisher = {{GI}}, title = {{{Combining Verifiers in Conditional Model Checking via Reducers}}}, doi = {{10.18420/se2019-46}}, volume = {{P-292}}, year = {{2019}}, } @inproceedings{10094, author = {{Sharma, Arnab and Wehrheim, Heike}}, booktitle = {{Software Engineering and Software Management, {SE/SWM} 2019, Stuttgart, Germany, February 18-22, 2019}}, editor = {{Becker, Steffen and Bogicevic, Ivan and Herzwurm, Georg and Wagner, Stefan}}, pages = {{157--158}}, publisher = {{{GI}}}, title = {{{Testing Balancedness of ML Algorithms}}}, doi = {{10.18420/se2019-48}}, volume = {{{P-292}}}, year = {{2019}}, } @inproceedings{30002, abstract = {{Utilisation of SiC semiconductors' fast switching speeds and high switching frequencies as a consequent are often in discussion. But which switching frequency is really optimal in terms of converter volume, losses and costs? Based on the example of a buck converter, this question is investigated, and a tool for loss calculation and design is described in this paper. A Pareto optimization of the converter is performed where the switching frequency is one of several design parameters. The buck converter can be realized by multiple rails interleaved, and several switches can be placed in parallel. Considered converter modes are continuous conduction mode, that allows hard-switching, ZVS, and incomplete ZVS depending on the switching frequency. Based on Pareto optimizations, a design is selected, and a laboratory sample of 5.5 kW for application in an EV battery charger is built up. Efficiencies of 99.5 % are achieved with switching frequencies of around 100 kHz.}}, author = {{Strothmann, Benjamin and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{2019 IEEE Applied Power Electronics Conference and Exposition (APEC)}}, publisher = {{IEEE}}, title = {{{Pareto Design and Switching Frequencies for SiC MOSFETs Applied in an 11 kW Buck Converter for EV-Charging}}}, doi = {{10.1109/apec.2019.8721850}}, year = {{2019}}, } @inproceedings{30334, author = {{Keuck, Lukas and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{Proc. 34th IEEE Applied Power Electronics Conference (APEC)}}, location = {{Anaheim, CA, USA}}, pages = {{1415 -- 1422}}, publisher = {{IEEE}}, title = {{{Computer-Aided Design and Optimization of an Integrated Transformer with Distributed Air Gap and Leakage Path for an LLC Resonant Converter}}}, year = {{2019}}, } @inproceedings{30335, author = {{Keuck, Lukas and Schafmeister, Frank and Böcker, Joachim and Jungwirth, Herbert and Schmidhuber, Michael}}, booktitle = {{Proc. IEEE International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management (PCIM)}}, location = {{Nuremberg, Germany}}, publisher = {{IEEE}}, title = {{{Computer-Aided Design and Optimization of an Integrated Transformer with Distributed Air Gap and Leakage Path for LLC Resonant Converter}}}, year = {{2019}}, } @inproceedings{24464, author = {{ Terhechte, Johannes and Berscheid, Anna Lena and Horwath, Ilona}}, location = {{Plzeň, Czech Republic}}, title = {{{DEVELOPMENT OF A CYBER-PHYSICAL SIMULATION ASSISTANCE SYSTEM FOR PARTIALLY AUTOMATED OPTIMIZATION OF THE EXTRUSION PROCESS}}}, year = {{2019}}, } @article{22047, abstract = {{Plastic freeforming (PF) is an additive-manufacturing process for producing three-dimensional plastic parts based on 3D CAD data by applying plastic droplets in layers. This process is used to produce customer-specific and complex geometries (prototypes and small series) on organic sheets. A comparable serial process is the injection of a second component onto organic sheets by injection molding. A sufficient bond between the PF structure and the organic sheets is of particular importance for each application. If this is not guaranteed, the composite system cannot withstand the mechanical load and fails. The force exerted on the system can no longer be transmitted between the PF structure and the organic sheet. The organic sheet is made of glass fiber-reinforced polypropylene (PP). The connection between the organic sheet and the PF structure is achieved by welding the molten polymer droplets and the surface of the organic sheet. The PF structures are made of PP to ensure sufficient compatibility with regard to the weldability of the components. The processing of PP in the PF process is a challenge because PP is a semicrystalline material. The shrinkage of semi-crystalline materials is significantly higher compared to amorphous materials. Due to the layered structure of the components, the shrinkage of the individual layers results in undesired warpage. The adhesive strength between the organic sheet and the PF structure is investigated by determining the bending strength in the 3-point bending test. The investigations include an optimization of the process parameters to maximize the adhesive strength. The experimental investigations show that an increase of the nozzle and build chamber temperature leads to a higher adhesive strength. In further investigations, the temperature of the nozzle shows no significant influence on the surface temperature despite the expected heat radiation. The surface temperature is almost only dependent on the temperature of the build chamber.}}, author = {{Moritzer, Elmar and Hirsch, André and Heim, H.P. and Cherif, C. and Truemper, W.}}, journal = {{Welding in the World}}, pages = {{867--873}}, publisher = {{Springer}}, title = {{{Plastic droplet welding: bond strength between plastic freeforming structures and continuous fiber-reinforced thermoplastic composites}}}, doi = {{10.1007/s40194-019-00714-3}}, volume = {{63}}, year = {{2019}}, } @inproceedings{22028, abstract = {{The mechanical properties of thin-walled plastic components are limited. One approach to improve the strength or stiffness of these components is to reinforce the thin-walled areas with an individually adapted Fused Deposition Modeling structure. Fused Deposition Modeling (FDM) is one of the most commonly used additive manufacturing processes. This process is characterized by the deposition of a fused, thermoplastic filament. Depending on the form of the reinforcement structure, the resulting hybrid structure should show higher strength or stiffness. The objective of the project is to determine constructive design and process guidelines for FDM structures. The FDM structure is to be used as a partial reinforcement for lightweight components and be adapted to the respective load conditions. Because of the lightweight application, the FDM structure should also have the lowest possible weight. The optimization of the FDM parts for different load cases is realized by adapting the design parameters. These parameters influence the layer generation and therefore also the inner structure of the FDM parts. In preliminary studies, the manufacturing restrictions of the FDM process are defined. The specimens are manufactured based on the Design of Experiments. To determine the static strength properties, different tests (tensile, compression, flexural, torsion and impact) are carried out. The investigations show that the filling strategy affects the mechanical properties. As a result of the investigations, design and process guidelines for the FDM structures are established according to the load conditions.}}, author = {{Moritzer, Elmar and Hirsch, André and Bürenhaus, Franziska Isabelle}}, booktitle = {{AIP Conference Proceedings}}, number = {{1}}, publisher = {{AIP Publishing}}, title = {{{Development and Modeling of Design and Process Guidelines for FDM Structures for the Partial Reinforcement of Hybrid Structures}}}, doi = {{10.1063/1.5088314}}, volume = {{2065}}, year = {{2019}}, } @article{4562, abstract = {{Employing main and sector-specific investment-grade CDS indices from the North American and European CDS market and performing mean-variance out-of-sample analyses for conservative and aggressive investors over the period from 2006 to 2014, this paper analyzes portfolio benefits of adding corporate CDS indices to a traditional financial portfolio consisting of stock and sovereign bond indices. As a baseline result, we initially find an increase in portfolio (downside) risk-diversification when adding CDS indices, which is observed irrespective of both CDS markets, investor-types and different sub-periods, including the global financial crisis and European sovereign debt crisis. In addition, the analysis reveals higher portfolio excess returns and performance in CDS index portfolios, however, these effects clearly differ between markets, investor-types and sub-periods. Overall, portfolio benefits of adding CDS indices mainly result from the fact that institutional investors replace sovereign bond indices rather than stock indices by CDS indices due to better risk-return characteristics. Our baseline findings remain robust under a variety of robustness checks. Results from sensitivity analyses provide further important implications for institutional investors with a strategic focus on a long-term conservative portfolio management.}}, author = {{Hippert, Benjamin and Uhde, André and Wengerek, Sascha Tobias}}, journal = {{Review of Derivatives Research }}, keywords = {{Corporate credit default swap indices, Mean-variance asset allocation, Out-of-sample portfolio optimization, Portfolio risk-diversification, Portfolio performance evaluation}}, number = {{2}}, pages = {{203--259}}, title = {{{Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe}}}, doi = {{https://doi.org/10.1007/s11147-018-9148-8}}, volume = {{22}}, year = {{2019}}, } @article{19300, author = {{Mäck, Markus and Caylak, Ismail and Edler, Philipp and Freitag, Steffen and Hanss, Michael and Mahnken, Rolf and Meschke, Günther and Penner, Eduard}}, issn = {{0936-7195}}, journal = {{GAMM-Mitteilungen}}, title = {{{Optimization with constraints considering polymorphic uncertainties}}}, doi = {{10.1002/gamm.201900005}}, year = {{2019}}, } @article{27026, abstract = {{While observational studies show an association between 25(OH)vitamin D concentrations and depressive symptoms, intervention studies, which examine the preventive effects of vitamin D supplementation on the development of depression, are lacking. To estimate the role of lowered 25(OH)vitamin D concentrations in the etiology of depressive disorders, we conducted a two-sample Mendelian randomization (MR) study on depression, i.e., “depressive symptoms” (DS, n = 161,460) and “broad depression” (BD, n = 113,769 cases and 208,811 controls). Six single nucleotide polymorphisms (SNPs), which were genome-wide significantly associated with 25(OH)vitamin D concentrations in 79,366 subjects from the SUNLIGHT genome-wide association study (GWAS), were used as an instrumental variable. None of the six SNPs was associated with DS or BD (all p > 0.05). MR analysis revealed no causal effects of 25(OH)vitamin D concentration, either on DS (inverse variance weighted (IVW); b = 0.025, SE = 0.038, p = 0.52) or on BD (IVW; b = 0.020, SE = 0.012, p = 0.10). Sensitivity analyses confirmed that 25(OH)vitamin D concentrations were not significantly associated with DS or BD. The findings from this MR study indicate no causal relationship between vitamin D concentrations and depressive symptoms, or broad depression. Conflicting findings from observational studies might have resulted from residual confounding or reverse causation.}}, author = {{Libuda, Lars and Laabs, Björn-Hergen and Ludwig, Christine and Bühlmeier, Judith and Antel, Jochen and Hinney, Anke and Naaresh, Roaa and Föcker, Manuel and Hebebrand, Johannes and König, Inke R. and Peters, Triinu}}, issn = {{2072-6643}}, journal = {{Nutrients}}, title = {{{Vitamin D and the Risk of Depression: A Causal Relationship? Findings from a Mendelian Randomization Study}}}, doi = {{10.3390/nu11051085}}, year = {{2019}}, } @article{27025, author = {{Knoll-Pientka, Nadja and Bühlmeier, Judith and Peters, Triinu and Albrecht, Muriel and Adams, Frederike and Wustrau, Katharina and Teufel, Martin and Hebebrand, Johannes and Föcker, Manuel and Libuda, Lars}}, issn = {{1590-1262}}, journal = {{Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity}}, pages = {{911--919}}, title = {{{Risk factors for a low weight gain in the early stage of adolescent anorexia nervosa inpatient treatment: findings from a pilot study}}}, doi = {{10.1007/s40519-019-00705-9}}, year = {{2019}}, }