@article{23052, author = {{Shareef, Zeeshan and Trächtler, Ansgar}}, journal = {{Robotica}}, number = {{06}}, pages = {{1322 -- 1334}}, title = {{{Simultaneous path planning and trajectory optimization for robotic manipulators using discrete mechanics and optimal control}}}, volume = {{34}}, year = {{2016}}, } @inproceedings{21688, abstract = {{Additive Manufacturing offers a great potential for the optimization of products. Therefore different approaches are feasible to exploit these potentials for elaborating optimal solutions. For example these include optimization of weight or stiffness of structural components as well as the integration of functions and other entities of assemblies. Note, however, that additive manufacturing processes have process specific limitations. Products, components and assemblies, as well as procedures for the design and production preparation must be optimized with regard to a successful additive manufacturing. The use of already known tools for the optimization and design needs to be reconsidered and adapted to theadditive manufacturing. This also includes the production planning with component orientation in build chamber as well as a necessary quality management system. This paper shows several ways for product optimization with additive manufacturing, often based on topology optimization, and procedures for information gathering, decision making and shape determination for part optimization for Additive Manufacturing.}}, author = {{Reiher, T. and Koch, R.}}, booktitle = {{27th Annual International Solid Freeform Fabrication Symposium }}, pages = {{2236--2249}}, title = {{{Product optimization with and for Additive Manufacturing}}}, doi = {{http://utw10945.utweb.utexas.edu/sites/default/files/2016/179-Reiher.pdf}}, volume = {{27}}, year = {{2016}}, } @inproceedings{21702, abstract = {{Nowadays, the material efficiency and part reliability are two majorissues in product development. Thus a product optimization often requires complex structures that are hard to be manufactured conventionally. Additive Manufacturing (AM) however offers great potentials for producing complex shaped parts economically. Different approaches are feasible to exploit these potentials based on the part’s application from shape optimization of structural components to the integration of functions and other entities of assemblies. Several parameters are defined that influence the costs and quality of the future product and carefully have to be balanced. To do so, the use of already known tools for the optimization and design needs to be reconsidered and adapted to the special characteristics of AM. As not all optimization potentials can be realized perfectly, a decision methodology is required to obtain the relevant potentials and to get to a trade-off between all requirements including the ecological impact. The paper shows different approaches for product optimization with AM and procedures for decision making in order to get to the optimal solution.}}, author = {{Reiher, T. and Deppe, G. and Koch, R.}}, booktitle = {{International Conference Production Engineering and Management 2016}}, isbn = {{978-3-946856-00-9}}, pages = {{27--38}}, title = {{{Combining material efficiency and part reliability by product optimization applying additive manufacturing}}}, doi = {{https://www.th-owl.de/elsa/download/333/334/PEM_2016_Proceeding_2016_09_14_Inhaltsnavigation.pdf}}, volume = {{6}}, year = {{2016}}, } @article{21730, author = {{Yanaka, K. and Yamanouchi, T.}}, journal = {{IEEE Computer Graphics and Applications}}, number = {{2}}, pages = {{68--73}}, publisher = {{Editors G. Domik and G. S. Owen}}, title = {{{3D Image Display Courses for Information Media Students}}}, doi = {{10.1109/MCG.2016.36}}, volume = {{36}}, year = {{2016}}, } @inproceedings{731, abstract = {{Traditional cellular networks are forced to remain active regardless of the actual amount of traffic that is currently produced/requested, with a clear waste of energy. Two-layer mobile networks with separated signalling and data layers have been recently proposed for energy savings in future implementations. These networks are able to switch off unneeded data cells completely while maintaining full coverage with their signalling cells, thus saving energy. In this demonstration, we showcase a testbed that uses Wi-Fi access points to emulate small cells of the data layer and a publicly available cellular connection as the signalling layer. We use off-the-shelf Android smartphones with an ad-hoc networking management module and a MultiPath TCP-enabled kernel to manage the Wi-Fi and cellular interfaces simultaneously. The testbed is used to demonstrate the general feasibility of this layered architecture and to facilitate experiments with network-wide resource optimization. }}, author = {{Peuster, Manuel and Karl, Holger and Enrico Redondi, Alessandro and Capone, Antonio}}, booktitle = {{IEEE Conference on Computer Communications Workshops, INFOCOM Workshops 2016, San Francisco, CA, USA, April 10-14, 2016}}, location = {{San Francisco}}, pages = {{1015----1016}}, title = {{{Demonstrating on-demand cell switching with a two-layer mobile network testbed}}}, doi = {{10.1109/INFCOMW.2016.7562232}}, year = {{2016}}, } @article{7484, author = {{Hoffmann, Sandro Phil and Albert, Maximilian and Meier, Cedrik}}, issn = {{0749-6036}}, journal = {{Superlattices and Microstructures}}, pages = {{397--408}}, publisher = {{Elsevier BV}}, title = {{{Fabrication of fully undercut ZnO-based photonic crystal membranes with 3D optical confinement}}}, doi = {{10.1016/j.spmi.2016.07.006}}, volume = {{97}}, year = {{2016}}, } @inproceedings{8759, abstract = {{In a wide range of applications, it is desirable to optimally control a 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 it is not possible to compute the entire control trajectory in advance, for instance due to uncertainties or unforeseeable events, model predictive control methods can be applied to control the system during operation in real time. In this article, we present an algorithm for the solution of multiobjective model predictive control problems. In an offline scenario, it can be used to compute the entire set of optimal compromises whereas in a real time scenario, one optimal compromise is computed according to an operator's preference. The results are illustrated using the example of an industrial laundry. A logistics model of the laundry is developed and then utilized in the optimization routine. Results are presented for an offline as well as an online scenario.}}, author = {{Peitz, Sebastian and Gräler, Manuel and Henke, Christian and Molo, Mirko Hessel-von and Dellnitz, Michael and Trächtler, Ansgar}}, booktitle = {{Procedia Technology}}, issn = {{2212-0173}}, pages = {{483--490}}, title = {{{Multiobjective Model Predictive Control of an Industrial Laundry}}}, doi = {{10.1016/j.protcy.2016.08.061}}, year = {{2016}}, } @article{9957, abstract = {{Leistungshalbleitermodule werden leistungsfähiger, effizienter, kompakter und haltbarer Ziel dieses Innovationsprojekts des Spitzenclusters „it’s OWL – Intelligente Technische Systeme OstWestfalen-Lippe“ ist die Entwicklung von selbstoptimierenden Verfahren, um unter variablen Produktionsbedingungen zuverlässige Kupferbondverbindungen herstellen zu können. Die Ultraschall-Drahtbondmaschine erhält die Fähigkeit, sich automatisch an veränderte Bedingungen anzupassen. Hierzu wird der gesamte Prozess der Ultraschall-Verbindungsbildung modelliert und neueste Verfahren der Selbstoptimierung angewandt. Die Evaluierung erfolgt anhand eines Prototypen in Form einer modifizierten Bondmaschine. Intelligent production of heavy copper wire bonds It is the aim of this innovation-project to develop a self-optimization system for ultrasonic copper wire bonding. It is part of the leading edge cluster “it’s OWL”. The bonding machine will be able to react autonomously to changing boundary conditions to ensure constant and reliable bonding results. For this, the hole bonding process is modeled in great detail and newest self-optimization techniques are utilized. A prototype-system incorporated in a serial machine is used for evaluation.}}, author = {{Brökelmann, Michael and Unger, Andreas and Meyer, Tobias and Althoff, Simon and Sextro, Walter and Hunstig, Matthias and Biermann, Florian and Guth, Karsten}}, journal = {{wt-online}}, pages = {{512--519}}, title = {{{Kupferbondverbindungen intelligent herstellen}}}, volume = {{7/8}}, year = {{2016}}, } @inproceedings{9963, abstract = {{Tire-wheel assembly is the only connection between road and vehicle. Contacting directly with road within postcard size of contact area, it is mounted and guided by the suspension system. Therefore kinematics and compliances of suspension system greatly influence the frictional coupling of tire tread elements and road surface asperities by affecting pressure and sliding velocity distribution in the contact zone. This study emphasizes the development of a numerical methodology for frictional rolling contact analysis with focus on interaction of suspension system dynamics and tire-road contact using ADAMS. For this purpose a comprehensive flexible multibody system of the multi-link rear suspension is established, where both flexible and rigid bodies are modeled to allow large displacements with included elastic effects. To meet accuracy requirements for the high frequency applications, such as road excitations, the amplitude- and frequency-dependency of rubber-metal bushings is included. Furthermore the proposed flexible viscoelastic suspension model is enhanced by a Flexible Ring Tire Model (FTire), which describes a 3D tire dynamic response and covers any road excitations by tread submodel connected to road surface model. Concerning the verification and validation procedure numerous experiments are carried out to confirm the validity and the accuracy of both the developed submodels and the entire model. The devised approach makes it possible to investigate the influence of suspension system design on dynamical rolling contact and to evaluate tire tread wear. Therefore it can be a useful tool to predict frictional power distribution within the contact area under more realistic conditions.}}, author = {{Kohl, Sergej and Sextro, Walter and Schulze, Sebastian}}, booktitle = {{The 2nd International Conference on Automotive Innovation and Green Energy Vehicle (AiGEV 2016), Cyberjaya, Malaysia, 2016.}}, keywords = {{Kinematics and compliances, flexible viscoelastic suspension model, frictional rolling contact analysis, frictional power distribution.}}, pages = {{1--12}}, title = {{{Aspects of Flexible Viscoelastic Suspension Modeling for Frictional Rolling Contact Analysis using ADAMS}}}, year = {{2016}}, } @inproceedings{9966, abstract = {{Usage of copper wire bonds allows to push power boundaries imposed by aluminum wire bonds. Copper allows higher electrical, thermal and mechanical loads than aluminum, which currently is the most commonly used material in heavy wire bonding. This is the main driving factor for increased usage of copper in high power applications such as wind turbines, locomotives or electric vehicles. At the same time, usage of copper also increases tool wear and reduces the range of parameter values for a stable process, making the process more challenging. To overcome these drawbacks, parameter adaptation at runtime using self-optimization is desired. A self-optimizing system is based on system objectives that evaluate and quantify system performance. System parameters can be changed at runtime such that pre-selected objective values are reached. For adaptation of bond process parameters, model-based self-optimization is employed. Since it is based on a model of the system, the bond process was modeled. In addition to static model parameters such as wire and substrate material properties and vibration characteristics of transducer and tool, variable model inputs are process parameters. Main simulation result is bonded area in the wiresubstrate contact. This model is then used to find valid and optimal working points before operation. The working point is composed of normal force and ultrasonic voltage trajectories, which are usually determined experimentally. Instead, multiobjective optimalization is used to compute trajectories that simultaneously optimize bond quality, process duration, tool wear and probability of tool-substrate contacts. The values of these objectives are computed using the process model. At runtime, selection among pre-determined optimal working points is sufficient to prioritize individual objectives. This way, the computationally expensive process of numerically solving a multiobjective optimal control problem and the demanding high speed bonding process are separated. To evaluate to what extent the pre-defined goals of self-optimization are met, an offthe- shelf heavy wire bonding machine was modified to allow for parameter adaptation and for transmitting of measurement data at runtime. This data is received by an external computer system and evaluated to select a new working point. Then, new process parameters are sent to the modified bonding machine for use for subsequent bonds. With these components, a full self-optimizing system has been implemented.}}, author = {{Meyer , Tobias and Unger, Andreas and Althoff, Simon and Sextro, Walter and Brökelmann, Michael and Hunstig, Matthias and Guth, Karsten}}, booktitle = {{IEEE 66th Electronic Components and Technology Conference}}, keywords = {{Self-optimization, adaptive system, bond process, copper wire}}, pages = {{622--628}}, title = {{{Reliable Manufacturing of Heavy Copper Wire Bonds Using Online Parameter Adaptation}}}, doi = {{10.1109/ECTC.2016.215}}, year = {{2016}}, } @inproceedings{9968, abstract = {{To increase quality and reliability of copper wire bonds, self-optimization is a promising technique. For the implementation of self-optimization for ultrasonic heavy copper wire bonding machines, a model of stick-slip motion between tool and wire and between wire and substrate during the bonding process is essential. Investigations confirm that both of these contacts do indeed show stick-slip movement in each period oscillation. In a first step, this paper shows the importance of modeling the stick-slip effect by determining, monitoring and analyzing amplitudes and phase angles of tooltip, wire and substrate experimentally during bonding via laser measurements. In a second step, the paper presents a dynamic model which has been parameterized using an iterative numerical parameter identification method. This model includes Archard’s wear approach in order to compute the lost volume of tool tip due to wear over the entire process time. A validation of the model by comparing measured and calculated amplitudes of tool tip and wire reveals high model quality. Then it is then possible to calculate the lifetime of the tool for different process parameters, i.e. values of normal force and ultrasonic voltage.}}, author = {{Unger, Andreas and Schemmel, Reinhard and Meyer, Tobias and Eacock, Florian and Eichwald, Paul and Althoff, Simon and Sextro, Walter and Brökelmann, Michael and Hunstig, Matthias and Guth, Karsten}}, booktitle = {{Wear Modeling in Copper Wire Wedge Bonding. IEEE CPMT Symposium Japan, 2016}}, keywords = {{the Ultrasonic Wire Bonding Process}}, pages = {{251--254}}, title = {{{Validated Simulation of the Ultrasonic Wire Bonding Process}}}, year = {{2016}}, } @phdthesis{172, author = {{Stapel, Florian}}, publisher = {{Universität Paderborn}}, title = {{{Ontology-based representation of abstract optimization models for model formulation and system generation}}}, year = {{2016}}, } @inproceedings{11834, abstract = {{We present a system for the 4th CHiME challenge which significantly increases the performance for all three tracks with respect to the provided baseline system. The front-end uses a bi-directional Long Short-Term Memory (BLSTM)-based neural network to estimate signal statistics. These then steer a Generalized Eigenvalue beamformer. The back-end consists of a 22 layer deep Wide Residual Network and two extra BLSTM layers. Working on a whole utterance instead of frames allows us to refine Batch-Normalization. We also train our own BLSTM-based language model. Adding a discriminative speaker adaptation leads to further gains. The final system achieves a word error rate on the six channel real test data of 3.48%. For the two channel track we achieve 5.96% and for the one channel track 9.34%. This is the best reported performance on the challenge achieved by a single system, i.e., a configuration, which does not combine multiple systems. At the same time, our system is independent of the microphone configuration. We can thus use the same components for all three tracks.}}, author = {{Heymann, Jahn and Drude, Lukas and Haeb-Umbach, Reinhold}}, booktitle = {{Computer Speech and Language}}, title = {{{Wide Residual BLSTM Network with Discriminative Speaker Adaptation for Robust Speech Recognition}}}, year = {{2016}}, } @inproceedings{157, abstract = {{Consider a scheduling problem in which a set of jobs with interjob communication, canonically represented by a weighted tree, needs to be scheduled on m parallel processors interconnected by a shared communication channel. In each time step, we may allow any processed job to use a certain capacity of the channel in order to satisfy (parts of) its communication demands to adjacent jobs processed in parallel. The goal is to find a schedule that minimizes the makespan and in which communication demands of all jobs are satisfied.We show that this problem is NP-hard in the strong sense even if the number of processors and the maximum degree of the underlying tree is constant.Consequently, we design and analyze simple approximation algorithms with asymptotic approximation ratio 2-2/m in case of paths and a ratio of 5/2 in case of arbitrary trees.}}, author = {{König, Jürgen and Mäcker, Alexander and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{563----577}}, title = {{{Scheduling with Interjob Communication on Parallel Processors}}}, doi = {{10.1007/978-3-319-48749-6_41}}, year = {{2016}}, } @inproceedings{149, abstract = {{In this paper we consider a strategic variant of the online facility location problem. Given is a graph in which each node serves two roles: it is a strategic client stating requests as well as a potential location for a facility. In each time step one client states a request which induces private costs equal to the distance to the closest facility. Before serving, the clients may collectively decide to open new facilities, sharing the corresponding price. Instead of optimizing the global costs, each client acts selfishly. The prices of new facilities vary between nodes and also change over time, but are always bounded by some fixed value α. Both the requests as well as the facility prices are given by an online sequence and are not known in advance.We characterize the optimal strategies of the clients and analyze their overall performance in comparison to a centralized offline solution. If all players optimize their own competitiveness, the global performance of the system is O(√α⋅α) times worse than the offline optimum. A restriction to a natural subclass of strategies improves this result to O(α). We also show that for fixed facility costs, we can find strategies such that this bound further improves to O(√α).}}, author = {{Drees, Maximilian and Feldkord, Björn and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{593----607}}, title = {{{Strategic Online Facility Location}}}, doi = {{10.1007/978-3-319-48749-6_43}}, year = {{2016}}, } @article{139, abstract = {{We consider online optimization problems in which certain goods have to be acquired in order to provide a service or infrastructure. Classically, decisions for such problems are considered as final: one buys the goods. However, in many real world applications, there is a shift away from the idea of buying goods. Instead, leasing is often a more flexible and lucrative business model. Research has realized this shift and recently initiated the theoretical study of leasing models (Anthony and Gupta in Proceedings of the integer programming and combinatorial optimization: 12th International IPCO Conference, Ithaca, NY, USA, June 25–27, 2007; Meyerson in Proceedings of the 46th Annual IEEE Symposium on Foundations of Computer Science (FOCS 2005), 23–25 Oct 2005, Pittsburgh, PA, USA, 2005; Nagarajan and Williamson in Discret Optim 10(4):361–370, 2013) We extend this line of work and suggest a more systematic study of leasing aspects for a class of online optimization problems. We provide two major technical results. We introduce the leasing variant of online set multicover and give an O(log(mK)logn)-competitive algorithm (with n, m, and K being the number of elements, sets, and leases, respectively). Our results also imply improvements for the non-leasing variant of online set cover. Moreover, we extend results for the leasing variant of online facility location. Nagarajan and Williamson (Discret Optim 10(4):361–370, 2013) gave an O(Klogn)-competitive algorithm for this problem (with n and K being the number of clients and leases, respectively). We remove the dependency on n (and, thereby, on time). In general, this leads to a bound of O(lmaxloglmax) (with the maximal lease length lmax). For many natural problem instances, the bound improves to O(K2).}}, author = {{Abshoff, Sebastian and Kling, Peter and Markarian, Christine and Meyer auf der Heide, Friedhelm and Pietrzyk, Peter }}, journal = {{Journal of Combinatorial Optimization}}, number = {{4}}, pages = {{ 1197----1216}}, publisher = {{Springer}}, title = {{{Towards the price of leasing online}}}, doi = {{10.1007/s10878-015-9915-5}}, year = {{2016}}, } @article{144, abstract = {{Following the direction pioneered by Fiat and Papadimitriou in their 2010 paper [12], we study the complexity of deciding the existence of mixed equilibria for minimization games where players use valuations other than expectation to evaluate their costs. We consider risk-averse players seeking to minimize the sum V=E+R of expectationE and a risk valuationR of their costs; R is non-negative and vanishes exactly when the cost incurred to a player is constant over all choices of strategies by the other players. In a V-equilibrium, no player could unilaterally reduce her cost.Say that V has the Weak-Equilibrium-for-Expectation property if all strategies supported in a player's best-response mixed strategy incur the same conditional expectation of her cost. We introduce E-strict concavity and observe that every E-strictly concave valuation has the Weak-Equilibrium-for-Expectation property. We focus on a broad class of valuations shown to have the Weak-Equilibrium-for-Expectation property, which we exploit to prove two main complexity results, the first of their kind, for the two simplest cases of the problem:• Two strategies: Deciding the existence of a V-equilibrium is strongly NP-hard for the restricted class of player-specific scheduling games on two ordered links [22], when choosing R as (1)Var (variance), or (2)SD (standard deviation), or (3) a concave linear sum of even moments of small order.• Two players: Deciding the existence of a V-equilibrium is strongly NP-hard when choosing R as (1)γ⋅Var, or (2)γ⋅SD, where γ>0 is the risk-coefficient, or choosing V as (3) a convex combination of E+γ⋅Var and the concave ν-valuationν−1(E(ν(⋅))), where ν(x)=xr, with r≥2. This is a concrete consequence of a general strong NP-hardness result that only needs the Weak-Equilibrium-for-Expectation property and a few additional properties for V; its proof involves a reduction with a single parameter, which can be chosen efficiently so that each valuation satisfies the additional properties.}}, author = {{Monien, Burkhard and Mavronicolas, Marios}}, journal = {{Theoretical Computer Science}}, pages = {{67--96}}, publisher = {{Elsevier}}, title = {{{The complexity of equilibria for risk-modeling valuations}}}, doi = {{10.1016/j.tcs.2016.04.013}}, volume = {{634}}, year = {{2016}}, } @inproceedings{29962, author = {{Stille, Karl Stephan Christian and Böcker, Joachim and Fröhleke, Norbert and Bettentrup, Ralf and Kaiser, Ingo}}, booktitle = {{2016 4th International Istanbul Smart Grid Congress and Fair (ICSG)}}, publisher = {{IEEE}}, title = {{{Integration of home photovoltaic generation into electricity tariff for load optimization}}}, doi = {{10.1109/sgcf.2016.7492441}}, year = {{2016}}, } @inproceedings{29960, author = {{Stille, Karl Stephan Christian and Böcker, Joachim and Fröhleke, Norbert and Bettentrup, Ralf and Kaiser, Ingo}}, booktitle = {{2016 10th International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG)}}, publisher = {{IEEE}}, title = {{{Supervisional load optimization for households with intelligent domestic appliances}}}, doi = {{10.1109/cpe.2016.7544176}}, year = {{2016}}, } @inproceedings{30607, author = {{Henkenius, Carsten and Fröhleke, Norbert and Böcker, Joachim and Figge, Heiko}}, booktitle = {{2016 IEEE Applied Power Electronics Conference and Exposition (APEC)}}, publisher = {{IEEE}}, title = {{{Numerical optimization of passive line filter components for suppression of electromagnetic interference (EMI)}}}, doi = {{10.1109/apec.2016.7468073}}, year = {{2016}}, }