@inproceedings{20911, abstract = {{One approach to cope with the growing complexity of today’s embedded systems software, especially in the automotive domain, is component-based software development. For systems based on hierarchical component architectures like AUTOSAR and developed in conformance with process models such as Automotive SPICE, requirements should be specified for the whole system under development and partitioned subsequently onto the particular components across several hierarchy layers. In previous work, we developed a formal requirements engineering (RE) approach based on a recent Live Sequence Chart (LSC) variant, so-called Modal Sequence Diagrams (MSDs). This scenario-based RE approach allows to validate the requirements by means of simulation (i.e., the play-out algorithm originally conceived for LSCs) and to formally verify the requirements for consistency. However, these scenarios are specified on a plain structural basis that does not reflect the typical structure of component architectures, which are arranged in a hierarchical way and encompass ports, interfaces, and directed connectors. In order to tackle this problem, we introduce in this paper a modeling and simulation approach for MSDs based on hierarchical component architectures. By binding these two aspects together, we foster an integrated and iterative RE and component architecture design. }}, author = {{Holtmann, Jörg and Meyer, Matthias}}, booktitle = {{Proceedings of 11th Workshop Automotive Software Engineering}}, pages = {{2458–2472}}, publisher = {{Bonner Koellen Verlag}}, title = {{{Play-out for Hierarchical Component Architectures}}}, volume = {{P-220}}, year = {{2013}}, } @inproceedings{1799, author = {{Ali-Ahmad, Hassan and Cicconetti, Claudio and de la Oliva, Antonio and Draxler, Martin and Gupta, Rohit and Mancuso, Vincenzo and Roullet, Laurent and Sciancalepore, Vincenzo}}, booktitle = {{2013 Second European Workshop on Software Defined Networks}}, isbn = {{9781479924332}}, publisher = {{IEEE}}, title = {{{CROWD: An SDN Approach for DenseNets}}}, doi = {{10.1109/ewsdn.2013.11}}, year = {{2013}}, } @inbook{1804, author = {{de la Oliva, Antonio and Morelli, Arianna and Mancuso, Vincenzo and Draexler, Martin and Hentschel, Tim and Melia, Telemaco and Seite, Pierrick and Cicconetti, Claudio}}, booktitle = {{Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering}}, isbn = {{9783642379345}}, issn = {{1867-8211}}, pages = {{28--41}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Denser Networks for the Future Internet, the CROWD Approach}}}, doi = {{10.1007/978-3-642-37935-2_3}}, year = {{2013}}, } @inproceedings{23137, author = {{Bauer, Frank and Gausemeier, Jürgen and Köchling, Daniel and Oestersötebier, Felix}}, booktitle = {{Smart Product Engineering - Proceedings of the 23rd CIRP Design Conference}}, publisher = {{Springer Berlin/Heidelberg}}, title = {{{Approach for an Early Validation of Mechatronic Systems using Idealized Simulation Models within the Conceptual Design}}}, year = {{2013}}, } @article{21935, author = {{Noé, Frank and Nüske, Feliks}}, issn = {{1540-3459}}, journal = {{Multiscale Modeling & Simulation}}, pages = {{635--655}}, title = {{{A Variational Approach to Modeling Slow Processes in Stochastic Dynamical Systems}}}, doi = {{10.1137/110858616}}, year = {{2013}}, } @inproceedings{481, abstract = {{Cloud computing offers high availability, dynamic scalability, and elasticity requiring only very little administration. However, this service comes with financial costs. Peer-to-peer systems, in contrast, operate at very low costs but cannot match the quality of service of the cloud. This paper focuses on the case study of Wikipedia and presents an approach to reduce the operational costs of hosting similar websites in the cloud by using a practical peer-to-peer approach. The visitors of the site are joining a Chord overlay, which acts as first cache for article lookups. Simulation results show, that up to 72% of the article lookups in Wikipedia could be answered by other visitors instead of using the cloud.}}, author = {{Graffi, Kalman and Bremer, Lars}}, booktitle = {{Proceedings of the International Conference on Communications (ICC'13)}}, pages = {{3444 -- 3449 }}, title = {{{Symbiotic Coupling of P2P and Cloud Systems: The Wikipedia Case}}}, doi = {{10.1109/ICC.2013.6655082}}, year = {{2013}}, } @inbook{8789, author = {{Reuter, Dirk and Gerth, Gerhard and Kirschner, J.}}, booktitle = {{Surface Diffusion}}, isbn = {{9781489902641}}, issn = {{0258-1221}}, title = {{{Surface Diffusion of 3d-Metals on W(110)}}}, doi = {{10.1007/978-1-4899-0262-7_43}}, year = {{2013}}, } @inproceedings{9855, abstract = {{During wheel bumping caused by stochastic road excitation, the wheel performs rotational and translational movements. The bump and rebound wheel velocity leads to significant angular velocities based on the (elasto-)kinematics of the suspension system. Based on the gyroscopic effect, moments arise about the rotating wheel induced by the angular change while bumping. Therefore it leads to undesirable wheel changes and degrades the tire contact and finally decreases the driving stability. A flexible MBS-model of the five-link rear axle system that includes these effects has been built up to allow a detailed investigation of the gyroscopic effect. Using the simulation results, conclusions can be drawn for refining design criteria for the kinematics, elastokinematics and topology of the suspension system to increase the active safety of the vehicle}}, author = {{Kohl, Sergej and Zuber, Armin and Sextro, Walter}}, booktitle = {{Proc. Appl. Math. Mech.}}, pages = {{23--24}}, title = {{{Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems}}}, doi = {{10.1002/pamm.201310007}}, volume = {{13}}, year = {{2013}}, } @misc{9863, abstract = {{The 9th International Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA 2012) was successfully held on 22–25 April 2012 in Hirosaki, Japan. The general chair was Prof. M.K. Kurosawa from the Tokyo Institute of Technology, Japan. In the past, Korea, Germany, Turkey, China, and USA have hosted the annual conference, but this was the first time for the annual IWPMA conference to be held in Japan. The IWPMA 2012 was organized as a joint symposium with JTTAS Smart Actuator/Sensor Study Committee and ICAT International Actuator Symposium. More than 150 people from the world (12 countries) participated and had fruitful discussions with 138 presentations including 11 invited talks. In addition to piezoelectric materials and piezoelectric actuators, the presentation topics were expanded to include solid-state actuators, energy harvesting, multifunctional materials, and other current important issues. It is our honor to pronounce that the “Sensors and Actuators A” journal has published this special issue on the IWPMA 2012 including the best 25 contributions. This issue covers the functional materials, such as piezoelectric and magnetostrictive materials, and their applications. However, for the innovative devices, various ideas concerning materials, mechanisms, designs, fabrication process, and control-systems are also required to be organically combined. From the view of this concept, we believe the published 25 papers can excite the researcher's intellectual curiosity concerning these issues and can serve as the driving force for further breakthroughs. Please enjoy the latest research results selected by our editor team. Finally, we appreciate all participants in the IWPMA 2012 and the devoted reviewers for the publication. We hope that the papers in this special issue will open up the next researches, which will be presented in the future IWPMA conferences.}}, booktitle = {{Sensors and Actuators A: Physical}}, editor = {{Morita, Takeshi and Hemsel, Tobias and Ijima, T. and Jeong, D. Y. and Kanda, T. and Twiefel, Jens and Uzgur, E. and Lallart, M.}}, location = {{Hirosaki}}, pages = {{1--172}}, publisher = {{Elsevier}}, title = {{{Selected Papers from the 9th International Workshop on Piezoelectric Materials and Applications in Actuators}}}, doi = {{10.1016/j.sna.2013.06.017}}, volume = {{200}}, year = {{2013}}, } @inproceedings{508, abstract = {{The process of planning a virtual topology for a Wavelength Devision Multiplexing (WDM) network is called Virtual Topology Design (VTD). The goal of VTD is to find a virtual topology that supports forwarding the expected traffic without congestion. In networks with fluctuating, high traffic demands, it can happen that no single topology fits all changing traffic demands occurring over a longer time. Thus, during operation, the virtual topology has to be reconfigured. Since modern networks tend to be large, VTD algorithms have to scale well with increasing network size, requiring distributed algorithms. Existing distributed VTD algorithms, however, react too slowly on congestion for the real-time reconfiguration of large networks. We propose Selfish Virtual Topology Reconfiguration (SVTR) as a new algorithm for distributed VTD. It combines reconfiguring the virtual topology and routing through a Software Defined Network (SDN). SVTR is used for online, on-the-fly network reconfiguration. Its integrated routing and WDM reconfiguration keeps connection disruption due to network reconfiguration to a minimum and is able to react very quickly to traffic pattern changes. SVTR works by iteratively adapting the virtual topology to the observed traffic patterns without global traffic information and without future traffic estimations. We evaluated SVTR by simulation and found that it significantly lowers congestion in realistic networks and high load scenarios.}}, author = {{Wette, Philip and Karl, Holger}}, booktitle = {{Proceedings of the 19th IEEE International Workshop on Local and Metropolitan Area Networks (IEEE LANMAN)}}, pages = {{1 -- 6 }}, title = {{{On the Quality of Selfish Virtual Topology Reconfiguration in IP-over-WDM Networks}}}, doi = {{10.1109/LANMAN.2013.6528271}}, year = {{2013}}, } @inproceedings{513, abstract = {{This paper initiates the study of self-adjusting networks (or distributed data structures) whose topologies dynamically adapt to a communication pattern $\sigma$. We present a fully decentralized self-adjusting solution called SplayNet. A SplayNet is a distributed generalization of the classic splay tree concept. It ensures short paths (which can be found using local-greedy routing) between communication partners while minimizing topological rearrangements. We derive an upper bound for the amortized communication cost of a SplayNet based on empirical entropies of $\sigma$, and show that SplayNets have several interesting convergence properties. For instance, SplayNets features a provable online optimality under special requests scenarios. We also investigate the optimal static network and prove different lower bounds for the average communication cost based on graph cuts and on the empirical entropy of the communication pattern $\sigma$. From these lower bounds it follows, e.g., that SplayNets are optimal in scenarios where the requests follow a product distribution as well. Finally, this paper shows that in contrast to the Minimum Linear Arrangement problem which is generally NP-hard, the optimal static tree network can be computed in polynomial time for any guest graph, despite the exponentially large graph family. We complement our formal analysis with a small simulation study on a Facebook graph.}}, author = {{Avin, Chen and Häupler, Bernhard and Lotker, Zvi and Scheideler, Christian and Schmid, Stefan}}, booktitle = {{Proceedings of the 27th IEEE International Parallel and Distributed Processing Symposium (IPDPS)}}, pages = {{395--406}}, title = {{{Locally Self-Adjusting Tree Networks}}}, doi = {{10.1109/IPDPS.2013.40}}, year = {{2013}}, } @inproceedings{544, abstract = {{Comparative evaluations of peer-to-peer protocols through simulations are a viable approach to judge the performance and costs of the individual protocols in large-scale networks. In order to support this work, we enhanced the peer-to-peer systems simulator PeerfactSim.KOM with a fine-grained analyzer concept, with exhaustive automated measurements and gnuplot generators as well as a coordination control to evaluate a set of experiment setups in parallel. Thus, by configuring all experiments and protocols only once and starting the simulator, all desired measurements are performed, analyzed, evaluated and combined, resulting in a holistic environment for the comparative evaluation of peer-to-peer systems.}}, author = {{Feldotto, Matthias and Graffi, Kalman}}, booktitle = {{Proceedings of the International Conference on High Performance Computing and Simulation (HPCS'13)}}, pages = {{99--106}}, title = {{{Comparative Evaluation of Peer-to-Peer Systems Using PeerfactSim.KOM}}}, doi = {{10.1109/HPCSim.2013.6641399}}, year = {{2013}}, } @inproceedings{546, abstract = {{Self-stabilization is the property of a system to transfer itself regardless of the initial state into a legitimate state. Chord as a simple, decentralized and scalable distributed hash table is an ideal showcase to introduce self-stabilization for p2p overlays. In this paper, we present Re-Chord, a self-stabilizing version of Chord. We show, that the stabilization process is functional, but prone to strong churn. For that, we present Ca-Re-Chord, a churn resistant version of Re-Chord, that allows the creation of a useful DHT in any kind of graph regardless of the initial state. Simulation results attest the churn resistance and good performance of Ca-Re-Chord.}}, author = {{Graffi, Kalman and Benter, Markus and Divband, Mohammad and Kniesburges, Sebastian and Koutsopoulos, Andreas}}, booktitle = {{Proceedings of the Conference on Networked Systems (NetSys)}}, pages = {{27--34}}, title = {{{Ca-Re-Chord: A Churn Resistant Self-stabilizing Chord Overlay Network}}}, doi = {{10.1109/NetSys.2013.11}}, year = {{2013}}, } @techreport{557, abstract = {{Since the last two decades, the water consumption in Germany is decreasing, which causes the water tanks and pipes in a water supply system to work inefficiently. This paper proposes an approach for a decision support system, which helps to decide how to plan new water tanks and resize existing tanks in water supply systems. The approach uses a combination of network reduction, mathematical optimization and hydraulic simulation. The mathematical optimization model is a nonconvex Mixed Integer Quadratically Constrained Program (MIQCP), which is solved by a piecewise linearization. As this may lead to many binary variables and therefore high computational times, the size of the water supply system model is reduced before building the optimization model. By applying several network reduction techniques there may occur some hydraulic differences between the original network model and the reduced network model. To make sure that the solution obtained in the optimization process is feasible in the original water supply system, the solution is verified by a hydraulic simulation tool.}}, author = {{Hallmann, Corinna}}, publisher = {{Universität Paderborn}}, title = {{{An Approach for a Decision Support Systems to optimize Water Tanks in Water Supply Systems by combining Network Reduction, Optimization and Simulation}}}, year = {{2013}}, } @inproceedings{559, abstract = {{Distributed hash tables are very versatile to use, as distributed storage is a desirable feature for various applications. Typical structured overlays like Chord, Pastry or Kademlia consider only homogeneous nodes with equal capacities, which does not resemble reality. In a practical use case, nodes might get overloaded by storing popular data. In this paper, we present a general approach to enable capacity awareness and load-balancing capability of homogeneous structured overlays. We introduce a hierarchical second structured overlay aside, which allows efficient capacity-based access on the nodes in the system as hosting mirrors. Simulation results show that the structured overlay is able to store various contents, such as of a social network, with only a negligible number of overloaded peers. Content, even if very popular, is hosted by easily findable capable peers. Thus, long-existing and well-evaluated overlays like Chord or Pastry can be used to create attractive DHT-based applications.}}, author = {{Wette, Philip and Graffi, Kalman}}, booktitle = {{Proceedings of the Conference on Networked Systems (NetSys)}}, pages = {{35--42}}, title = {{{Adding Capacity-Aware Storage Indirection to Homogeneous Distributed Hash Tables}}}, doi = {{10.1109/NetSys.2013.9}}, year = {{2013}}, } @inproceedings{10745, author = {{Toebermann, Christian and Geibel, Daniel and Hau, Manuel and Brandl, Ron and Kaufmann, Paul and Ma, Chenjie and Braun, Martin and Degner, Tobias}}, booktitle = {{Real-Time Conference}}, publisher = {{OPAL RT Paris}}, title = {{{Real-Time Simulation of Distribution Grids with high Penetration of Regenerative and Distributed Generation}}}, year = {{2013}}, } @inproceedings{12064, author = {{Sommer, Christoph and Joerer, Stefan and Dressler, Falko}}, booktitle = {{2012 IEEE Vehicular Networking Conference (VNC)}}, isbn = {{9781467349963}}, title = {{{On the applicability of Two-Ray path loss models for vehicular network simulation}}}, doi = {{10.1109/vnc.2012.6407446}}, year = {{2013}}, } @inproceedings{15094, author = {{Böttcher, Stefan and Brandenburg, Marc and Hartel, Rita}}, booktitle = {{WEBIST 2013 - Proceedings of the 9th International Conference on Web Information Systems and Technologies}}, pages = {{137--140}}, publisher = {{SciTePress}}, title = {{{DAG - Index - A Compressed Index for XML Keyword Search}}}, year = {{2013}}, } @book{1626, author = {{Krimphove, Dieter}}, pages = {{266}}, publisher = {{Verlag Kovač}}, title = {{{"Ihr betet an, was ihr nicht kennt" (Jo 4, 22) - Eine neue Sicht auf die Trinität }}}, year = {{2013}}, } @inproceedings{16340, abstract = {{Today’s simulation software normally has fixed, built-in editing and visualization views adapted to a specific problem domain. Often this monolithic concept prevents collaborative editing altogether. Even with more flexible concepts, editing simulation models with a heterogeneous set of clients is not possible. In this article we describe a flexible concept for collaborative editing of simulation models with heterogeneous clients, such as web-based, desktop and mobile clients. The clients may even show different editing views adapted to the user’s role. The concept we describe in this paper overcomes several problems: First we need to be able to connect and manage a set of heterogeneous clients in the simulation software. The very different user inputs from the connected clients then need to be processed, interpreted and combined to allow editing in a collaborative way for all users. At last we show a prototypical integration of the presented concept into our research platform d3fact.}}, author = {{Renken, Hendrik and Brandt, Sascha and Eichert, Felix A. and Klaas, Alexander}}, booktitle = {{Volume 2: 32nd Computers and Information in Engineering Conference, Parts A and B}}, isbn = {{9780791845011}}, location = {{Chicago, Illinois, USA}}, pages = {{1491--1500}}, title = {{{Visualization and Collaborative Editing of Simulation Models With Heterogeneous Clients: Implemented Into the Simulator D3FACT}}}, doi = {{10.1115/detc2012-71370}}, volume = {{2}}, year = {{2013}}, }