@inproceedings{23183, author = {{Witting, Katrin and Dellnitz, Michael and Geisler, Jens and Trächtler, Ansgar and Walther, Andrea}}, booktitle = {{International Conference on Simulation Technology – SIMTECH }}, title = {{{Fast Pareto set computation using algorithmic differentiation applied to the guidance of a rail-bound vehicle}}}, year = {{2011}}, } @inproceedings{2195, author = {{Grawinkel, Matthias and Schäfer, Thorsten and Brinkmann, André and Hagemeyer, Jens and Porrmann, Mario}}, booktitle = {{Proc. Int. Symp. on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS)}}, pages = {{297--306}}, publisher = {{IEEE Computer Society}}, title = {{{Evaluation of Applied Intra-Disk Redundancy Schemes to Improve Single Disk Reliability}}}, doi = {{10.1109/mascots.2011.13}}, year = {{2011}}, } @inproceedings{799, author = {{Volkhausen, Tobias and Schinköthe, Kai and Karl, Holger}}, booktitle = {{IEEE 8th International Conference on Mobile Adhoc and Sensor Systems, MASS 2011, Valencia, Spain, October 17-22, 2011}}, pages = {{146----148}}, title = {{{Coding Opportunities from Similar Data in Wireless Cooperation Diversity Systems}}}, doi = {{10.1109/MASS.2011.126}}, year = {{2011}}, } @inproceedings{800, author = {{Biermann, Thorsten and Scalia, Luca and Karl, Holger}}, booktitle = {{Proceedings of the 14th International Symposium on Modeling Analysis and Simulation of Wireless and Mobile Systems, MSWiM 2011, Miami, Florida, USA, October 31 - November 4, 2011}}, pages = {{265----274}}, title = {{{Designing optical metro and access networks for future cooperative cellular systems}}}, doi = {{10.1145/2068897.2068945}}, year = {{2011}}, } @article{6425, abstract = {{Recently, many efforts have been made to develop more efficient Inter-Vehicle Communication (IVC) protocols for on-demand route planning according to observed traffic congestion or incidents, as well as for safety applications. Because practical experiments are often not feasible, simulation of network protocol behavior in Vehicular Ad Hoc Network (VANET) scenarios is strongly demanded for evaluating the applicability of developed network protocols. In this work, we discuss the need for bidirectional coupling of network simulation and road traffic microsimulation for evaluating IVC protocols. As the selection of a mobility model influences the outcome of simulations to a great deal, the use of a representative model is necessary for producing meaningful evaluation results. Based on these observations, we developed the hybrid simulation framework Veins (Vehicles in Network Simulation), composed of the network simulator OMNeT++ and the road traffic simulator SUMO. In a proof-of-concept study, we demonstrate its advantages and the need for bidirectionally coupled simulation based on the evaluation of two protocols for incident warning over VANETs. With our developed methodology, we can advance the state-of-the-art in performance evaluation of IVC and provide means to evaluate developed protocols more accurately. }}, author = {{Sommer, Christoph and German, Reinhard and Dressler, Falko}}, journal = {{IEEE Transactions on Mobile Computing}}, number = {{1}}, pages = {{3--15}}, publisher = {{IEEE}}, title = {{{Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis}}}, doi = {{10.1109/TMC.2010.133}}, volume = {{10}}, year = {{2011}}, } @article{9767, abstract = {{The paper presents the results of numerical and experimental investigation of cylindrical piezoelectric actuator used for achieving independent three degrees of freedom oscillations of the contact point. The design of actuator based on a hollow piezoelectric cylinder mounted on a metal rod. The piezoceramic cylinder has a radial polarization and special configuration of the electrodes that cover inner and outer surface of the cylinder. The main advantage of actuator's design is that solid metallic rod operates as a part of inner electrode of the cylinder and a stator of actuator. The geometry of piezoelectric actuator was adopted to reach resonance of oscillations for the first longitudinal mode and the third flexural mode at same frequency. The actuator is designed to move positioned object through contact point which is located on the top of the rod. The optimal topology of electrodes was found to achieve longitudinal and flexural oscillations of the actuator in two perpendicular planes. Three degrees of freedom of the positioning object can be achieved and control of the system can be implemented by applying different excitation schemes and regimes. The numerical simulation and experimental study of piezoelectric actuator was performed. Impedance of actuator was analyzed under different excitation regimes. The results of numerical modeling and experimental study were compared. Recommendations for the further development of this type of actuator are given.}}, author = {{Lucinskis, Raimundas and Mazeika, Dalius and Hemsel, Tobias and Bansevicius, Ramutis}}, journal = {{AIP Conference Proceedings}}, keywords = {{dielectric polarisation, piezoceramics, piezoelectric actuators}}, number = {{1}}, pages = {{693--696}}, publisher = {{AIP}}, title = {{{Multi-DOF cylindrical piezoelectric actuator with radial polarization}}}, doi = {{10.1063/1.3703277}}, volume = {{1433}}, year = {{2011}}, } @article{4150, abstract = {{Atomistic simulations on the silicon carbide precipitation in bulk silicon employing both, classical potential and first-principlesmethods are presented. The calculations aim at a comprehensive,microscopic understanding of the precipitation mechanism in the context of controversial discussions in the literature. For the quantum-mechanical treatment, basic processes assumed in the precipitation process are calculated in feasible systems of small size. The migration mechanism of a carbon 100 interstitial and silicon 11 0 self-interstitial in otherwise defect-free silicon are investigated using density functional theory calculations. The influence of a nearby vacancy, another carbon interstitial and a substitutional defect as well as a silicon self-interstitial has been investigated systematically. Interactions of various combinations of defects have been characterized including a couple of selected migration pathways within these configurations. Most of the investigated pairs of defects tend to agglomerate allowing for a reduction in strain. The formation of structures involving strong carbon–carbon bonds turns out to be very unlikely. In contrast, substitutional carbon occurs in all probability. A long range capture radius has been observed for pairs of interstitial carbon as well as interstitial carbon and vacancies. A rather small capture radius is predicted for substitutional carbon and silicon self-interstitials. Initial assumptions regarding the precipitation mechanism of silicon carbide in bulk silicon are established and conformability to experimental findings is discussed. Furthermore, results of the accurate first-principles calculations on defects and carbon diffusion in silicon are compared to results of classical potential simulations revealing significant limitations of the latter method. An approach to work around this problem is proposed. Finally, results of the classical potential molecular dynamics simulations of large systems are examined, which reinforce previous assumptions and give further insight into basic processes involved in the silicon carbide transition.}}, author = {{Zirkelbach, F. and Stritzker, B. and Nordlund, K. and Lindner, Jörg and Schmidt, W. G. and Rauls, E.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{6}}, publisher = {{American Physical Society (APS)}}, title = {{{Combinedab initioand classical potential simulation study on silicon carbide precipitation in silicon}}}, doi = {{10.1103/physrevb.84.064126}}, volume = {{84}}, year = {{2011}}, } @misc{10678, author = {{Ikonomakis, Nikolaos}}, publisher = {{Paderborn University}}, title = {{{PinSim: Schnelle Simulation mit Pintools}}}, year = {{2011}}, } @article{11850, abstract = {{In this paper, we present a novel blocking matrix and fixed beamformer design for a generalized sidelobe canceler for speech enhancement in a reverberant enclosure. They are based on a new method for estimating the acoustical transfer function ratios in the presence of stationary noise. The estimation method relies on solving a generalized eigenvalue problem in each frequency bin. An adaptive eigenvector tracking utilizing the power iteration method is employed and shown to achieve a high convergence speed. Simulation results demonstrate that the proposed beamformer leads to better noise and interference reduction and reduced speech distortions compared to other blocking matrix designs from the literature.}}, author = {{Krueger, Alexander and Warsitz, Ernst and Haeb-Umbach, Reinhold}}, journal = {{IEEE Transactions on Audio, Speech, and Language Processing}}, keywords = {{acoustical transfer function ratio, adaptive eigenvector tracking, array signal processing, beamformer design, blocking matrix, eigenvalues and eigenfunctions, eigenvector-based transfer function ratios estimation, generalized sidelobe canceler, interference reduction, iterative methods, power iteration method, reduced speech distortions, reverberant enclosure, reverberation, speech enhancement, stationary noise}}, number = {{1}}, pages = {{206--219}}, title = {{{Speech Enhancement With a GSC-Like Structure Employing Eigenvector-Based Transfer Function Ratios Estimation}}}, doi = {{10.1109/TASL.2010.2047324}}, volume = {{19}}, year = {{2011}}, } @article{11993, author = {{Dressler, Falko and Sommer, Christoph and Eckhoff, David and Tonguz, Ozan}}, issn = {{1556-6072}}, journal = {{IEEE Vehicular Technology Magazine}}, pages = {{43--51}}, title = {{{Toward Realistic Simulation of Intervehicle Communication}}}, doi = {{10.1109/mvt.2011.941898}}, year = {{2011}}, } @article{16239, author = {{Hankeln, Frederik and Mahnken, Rolf}}, issn = {{1617-7061}}, journal = {{PAMM}}, pages = {{379--380}}, title = {{{Simulation of Deep Drawing of Carbon Fibre Prepregs}}}, doi = {{10.1002/pamm.201110181}}, year = {{2011}}, } @inproceedings{14013, abstract = {{Modeling and simulation play a key-role in computer-assisted design of ultrasonic sensors. The accuracy of those numerical or analytical models highly depends on the material dataset chosen as well as on the digitized simplified geometry. Thus, researchers worked on techniques how to measure material datasets of piezoceramics or passive materials (i.e. polymers) for use in simulation [Rau08] [Rup09]. Most computer models neglect the influence of adhesive bonds between those active and passive material components used to form a complete ultrasonic transducer and thus imply perfect interface layers. To gain a more accurate model one need to go further and consider non-perfect interface layers between assembly parts. Because adhesive bonds are neither necessarily isotropic nor homogeneous and their geometric dimensions are very small, we need to define effective material datasets dependent on the model used in simulation. In this contribution the indicator under study is the electric impedance of the active element. We will show the influence of different adhesives used to adhere metal electrodes on piezoceramic discs. Therefore, we use several different types of adhesives (epoxies, cyanoacrylates and perfluorpolyether grease) and different sizes of piezoceramic discs (PIC 255, manufacturer: PI Ceramic GmbH) of the same batch (thickness, diameter). The electrodes have been cut from one plate made of stainless steel using a laser to avoid uncertainty effects due to variations in material-parameters. The probes have been prepared in an air-conditioned Lab with constant temperature and humidity. The indicators considered to identify the effect of those different adhesive films are extracted from the electric impedance of the electromechanical converter.}}, author = {{Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, location = {{Chengdu, China}}, pages = {{18--23}}, title = {{{Analyzing the effect of adhered metal electrodes on piezoelectric elements using different types of adhesives}}}, volume = {{3}}, year = {{2011}}, } @inproceedings{14016, abstract = {{There has been a lot of progress in finding measurable quantities of high in- formation content for the inverse determination of piezoelectric material properties. Since some material parameters (mainly \textgreek{e}S 11, e15and cE 44) do not or only marginally influence the electrical impedance over frequency, it is not sufficient to look only at the electri- cal impedance of discoidal piezoceramics [1]. Moreover, the parameter sensitivities vary with respect to the diameter--thickness ratio of the disc and the design of an ultrasonic transducer's piezoceramic has to match other requirements than those of a good material characterization [2, 3]. That is why it is still desirable to find model based approaches for parameter identification that either keep the technical effort low (e.g., only an impedance measurement) or increase speed of the inversion procedure. In this contribution we answer the question if an additional analytical approximation of cE 44, strictly following the ideas of Theocaris [4], in conjunction with a single measured elec- trical impedance will be sufficient for an accurate simulation of both, electrical impedance and surface normal velocity of a piezoceramic disc. Thereby, the remaining parameters are identified by means of the Inverse Method. Furthermore, we use the parameter ap- proximation as an initial guess and limiting boundary to speed up the inverse algorithm if both, electrical impedance and surface normal velocity are taken into account within the optimization procedure.}}, author = {{Rautenberg, Jens and Rupitsch, Stefan J. and Henning, Bernd and Lerch, Reinhard}}, booktitle = {{7th International Workshop on Direct and Inverse Problems in Piezoelectricity}}, title = {{{Utilizing an Analytical Approximation for c44E to Enhance the Inverse Method for Material Parameter Identification of Piezoceramics}}}, year = {{2011}}, } @inproceedings{14550, abstract = {{For many applications like level measurement and industry robotics it is of advantage if the directional characteristic of an ultrasonic transducer is changeable or adaptable for the improvement of spatial resolution. Often this goal is reached with the use of ultrasonic transducer arrays, which elements are driven with phase shifted excitation signals. One disadvantage of these solutions is the great effort for building such an array and the multi-channel sensor electronics. In this contribution the directional characteristic of a single air transducer with segmented electrodes is analyzed. Therefore a variable script based finite element model is used to discover the influence of different electrode configurations on the directional characteristic of a single piezoceramic transducer. Especially the influence on the angle of beam and the near field length are evaluated. The used variable model permits an optimization of the configuration with regards to the mentioned criteria. The findings will be used for the development of a level measurement system for bulk solids.}}, author = {{Unverzagt, Carsten and Henning, Bernd}}, keywords = {{Elektrode}}, location = {{Gdansk, Poland}}, title = {{{Finite element simulation of single ultrasonic transducer with segmented electrodes to adjust the directional characteristic}}}, year = {{2011}}, } @inproceedings{30534, author = {{Lv, J. and Cao, Z. and Fröhleke, N. and Böcker, Joachim and Yuan, H. and Mi, H.}}, booktitle = {{Proceedings of the 2011 14th European Conference on Power Electronics and Applications}}, title = {{{Thermal-electrical modeling and simulation of resonantly operated DC-DC converters based on extended describing function method}}}, year = {{2011}}, } @inproceedings{26364, abstract = {{We propose the use of the material flow simulation to evaluate the robustness of a production plan, which was created and optimized with no respect to unforeseen derivations. Since the necessary probabilities for machine failures and similar operational events on the floor can easily be integrated in the simulation model, in order to analyze, how initial plan performs in these situations. The influence of unforeseen events in daily production cannot be modeled within mathematical optimization without consuming large amounts of computation time. We show a possible way to use simulation to evaluate and enhance a production plan. We illustrate the developed process using a real-world use-case of medium complexity and can show, that simulation is able to evaluate the robustness of a given pro-optimizes production plan. }}, author = {{Laroque, Christoph and Delius, Robin and Fischer, Jan-Hendrik and Horstkemper, Dennis}}, booktitle = {{Proceedings of The Third International Conference on Advances}}, pages = {{13--20}}, publisher = {{Xpert Publishing Services}}, title = {{{Increase of Robustness on Pre-optimized Production Plans Through Simulation-based Analysis and Evaluation}}}, year = {{2011}}, } @inproceedings{26417, author = {{Klaas, Alexander and Laroque, Christoph and Renken, Hendrik and Dangelmaier, Wilhelm}}, booktitle = {{Proceedings of The 25th European Simulation and Modelling Conference - ESM’2011}}, title = {{{Goal-Based Agents in Material Flow Simulations - Integration of an Agent Programming Framework in the Discrete Event Simulator D3FACT}}}, year = {{2011}}, } @inproceedings{26384, author = {{Renken, Hendrik and Laroque, Christoph and Fischer, Matthias}}, booktitle = {{Proceedings of The 25th European Simulation and Modelling Conference - ESM’2011}}, title = {{{An Easy Extendable Modeling Framework for Discrete Event Simulation Models and their Visualization}}}, year = {{2011}}, } @inproceedings{26387, author = {{Klaas, Alexander and Laroque, Christoph and Fischer, Matthias and Dangelmaier, Wilhelm}}, booktitle = {{Proceedings of the 2011 Winter Simulation Conference}}, title = {{{Simulation Aided, Knowledge Based Routing for AGVs in a Distribution Warehouse}}}, year = {{2011}}, } @inproceedings{26385, author = {{Klaas, Alexander and Laroque, Christoph and Renken, Hendrik and Dangelmaier, Wilhelm}}, booktitle = {{Proceedings of The 25th European Simulation and Modelling Conference - ESM’2011}}, title = {{{Goal-Based Agents in Material Flow Simulations - Integration of an Agent Programming Framework in the Discrete Event Simulator D3FACT}}}, year = {{2011}}, }