@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}}, } @inproceedings{9768, author = {{Lurie, Oleg and Kromov, Ivan and Trächtler, Ansgar and Sondermann-Wölke, Christoph and Sextro, Walter}}, booktitle = {{25. Tagung Technische Zuverlässigkeit (TTZ 2011) - Entwicklung und Betrieb zuverlässiger Produkte}}, pages = {{99--110}}, title = {{{Dependability Analysis of the Degradation Behavior of Mechatronics Systems with Different Operating Strategies}}}, year = {{2011}}, } @article{9769, abstract = {{In this study, we report some improvements in a hydrothermal method for lead-free piezoelectric powders and the performance of the sintered (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$ ceramics. To increase the obtained powder weight per source solution volume, the hydrothermal reaction conditions were modified. This improvement is important for mass production; however, it resulted in a larger particle size dispersion. Therefore, we examined to introduced the ball milling process that is useful for dense (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$ ceramics. When a large amount of powder was obtained, it took a long time to eliminate the residual alkaline ions in the hydrothermal powders by a washing process. Therefore, a neutralization was conducted in the powder washing process. Using this powder, a solid solution of (K,Na)NbO$_{3}$ceramics was synthesized. The relative density was successfully increased. Concerning the electrical properties, the relative permittivity was improved, and the piezoelectric constant d$_{33}$ was also increased from 114 to 130 pC/N.}}, author = {{Maeda, Takafumi and Hemsel, Tobias and Morita, Takeshi}}, journal = {{Japanese Journal of Applied Physics}}, pages = {{07HC01}}, publisher = {{The Japan Society of Applied Physics}}, title = {{{Improved Process for Hydrothermal Lead-Free Piezoelectric Powders and Performances of Sintered (K0.48Na0.52)NbO3 Ceramics}}}, volume = {{50}}, year = {{2011}}, } @inproceedings{9770, abstract = {{One cannot image today's life without mechatronic systems, which have to be developed in a joint effort by teams of mechanical engineers, electrical engineers, control engineers and software engineers. Often these systems are applied in safety critical environments like in cars or aircrafts. This requires systems that function correctly and do not cause hazardous situations. However, random errors due to wear or external influences cannot be completely excluded. Consequently, we have to perform a hazard analysis for the system. Further, the union of four disciplines in one system requires the development and analysis of the system as a whole. We present a component-based hazard analysis that considers the entire mechatronic system including hardware, i.e. mechanical and electrical components, and software components. Our approach considers the physical properties of different types of flow in mechatronic systems. We have identified reusable patterns for the failure behavior which can be generated automatically. This reduces the effort for the developer. As cycles, e.g. control cycles, are an internal part of every mechatronic system our approach is able to handle cycles. The presented approach has been applied to a real-life case study.}}, author = {{Priesterjahn, Claudia and Sondermann-Wölke, Christoph and Tichy, Mathias and Hölscher, Christian}}, booktitle = {{Proc. of the 2nd IEEE International Workshop MoBE-RTES at the 14th IEEE International Symposium on Object/Component/Service-oriented Real-time Distributed Computing (ISORC)}}, publisher = {{IEEE Computer Society}}, title = {{{Component-based Hazard Analysis for Mechatronic Systems}}}, year = {{2011}}, } @inproceedings{9771, abstract = {{Dieser Beitrag stellt ein Konzept vor, welches die Methode der Mehrzieloptimierung mit einer Online-Bewertung des aktuellen Systemzustands kombiniert. Dieses erlaubt Maßnahmen zur Zuverlässigkeitssteigerung abzuleiten. Das Konzept wird auf ein X-by-wire-Fahrzeug mit Einzelradaktorik angewandt. Dabei steht zunächst die Beeinflussung der Ziele der Mehrzieloptimierung zugunsten der Zuverlässigkeit des Systems im Vordergrund. In Simulationen wird gezeigt, dass über die Wahl und Gewichtung der Zielfunktionen die Quer- und Längskräfte an den Rädern vorteilhaft verteilt werden können. In this contribution a concept is illustrated, which combines the multi-objective optimization technique with an online assessment of the current system state. This allows deriving measures to increase the reliability of the system. The concept is applied to an X-by-wire vehicle with single-wheel actuators. The emphasis is here mostly on the influence of the objectives of the multiobjective optimization for the benefit of the reliability of the system. It is demonstrated in simulations, that the lateral and longitudinal forces at the wheels can be distributed advantageously by the selection of the suitable objective functions and the appropriate weights.}}, author = {{Sondermann-Wölke, Christoph and Sextro, Walter and Reinold, Peter and Trächtler, Ansgar}}, booktitle = {{25. Tagung Technische Zuverlässigkeit (TTZ 2011) - Entwicklung und Betrieb zuverlässiger Produkte}}, pages = {{291--302}}, title = {{{Zuverlässigkeitsorientierte Mehrzieloptimierung zur Aktorrekonfiguration eines X-by-wire-Fahrzeugs}}}, year = {{2011}}, } @article{9772, abstract = {{A profound description of friction in wheel--rail contact plays an essential role for optimization of traction control strategies, as input quantity for railway simulations in general and for the estimation of wear and rolling contact fatigue. A multitude of wheel--rail contact models exists, however, traction--creepage curves obtained from measurements show quantitative and qualitative deviations. There are several phenomena which influence the traction--creepage characteristics: Mechanisms resulting from surface roughness, frictional heating or the presence of interfacial fluids can have a dominating influence on friction. In this paper, a new wheel--rail contact model, accounting for these influential parameters, will be presented. The presented model accounts for the interaction of an interfacial fluid model for combined boundary and mixed lubrication of rough surfaces with a wheel--rail contact model that additionally accounts for frictional heating. A quantitative comparison with measurements found in the literature is not conducted, since the exact conditions of the measurements are mostly unknown and parameters can easily be adjusted to fit the measurements. Emphasis is placed on the qualitative behavior of the model with respect to the measurements and good agreement is found. The dependence of the maximum traction coefficient on rolling velocity, surface roughness and normal load is studied under dry and water lubricated conditions.}}, author = {{Tomberger, Christoph and Dietmaier, Peter and Sextro, Walter and Six, Klaus}}, issn = {{0043-1648}}, journal = {{Wear}}, keywords = {{Wheel--rail contact, Rolling contact, Friction, Interfacial fluid, Lubrication, Surface roughness, Contact temperature}}, pages = {{2 -- 12}}, title = {{{Friction in wheel--rail contact: A model comprising interfacial fluids, surface roughness and temperature}}}, doi = {{10.1016/j.wear.2010.10.025}}, volume = {{271}}, year = {{2011}}, } @article{9877, author = {{Isobe, Gaku and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, journal = {{Proceedings of Symposium on Ultrasonic Electronics}}, pages = {{19--20}}, publisher = {{Trans Tech Publ}}, title = {{{High temperature tolerant transducer for Ultrasonic Assisted Hydrothermal Method}}}, volume = {{32}}, year = {{2011}}, } @article{4157, author = {{Hehenkamp, Burkhard and Kaarboe, Oddvar}}, issn = {{0313-5926}}, journal = {{Economic Analysis and Policy}}, number = {{1}}, pages = {{49--70}}, publisher = {{Elsevier BV}}, title = {{{Paying for Performance in Hospitals}}}, doi = {{10.1016/s0313-5926(11)50004-9}}, volume = {{41}}, year = {{2011}}, } @misc{650, author = {{Platenius, Marie Christin}}, publisher = {{Universität Paderborn}}, title = {{{Reengineering of Design Deficiencies in Component-Based Software Architectures}}}, year = {{2011}}, } @inproceedings{652, abstract = {{In the development process of service-oriented systems, business process models are used at different levels. Typically, high-level business process models that describe business requirements and needs are stepwise refined to the IT level by different business modelers and software architects. As a result, different process model versions must be compared and merged by means of model version control. An important prerequisite for process model version control is an elaborated matching approach that results in precise mappings between different process model versions. The challenge of such an approach is to deal with syntactically different process models that are semantically equivalent. For that purpose, matching techniques must consider the semantics of process modeling languages.In this paper, we present a matching approach for process models in a versioning scenario. Based on a term formalization of process models, we enable an efficient and effective way to match syntactically different but semantically equivalent process models resulting in precise mappings.}}, author = {{Gerth, Christian and Luckey, Markus and Küster, Jochen and Engels, Gregor}}, booktitle = {{Proceedings of the IEEE 8th International Conference on Service Computingt (SCC)}}, pages = {{218----225}}, title = {{{Precise Mappings between Business Process Models in Versioning Scenarios}}}, doi = {{10.1109/SCC.2011.65}}, year = {{2011}}, } @misc{661, author = {{Arifulina, Svetlana}}, publisher = {{Universität Paderborn}}, title = {{{Coverage Criteria for Testing DMM Specifications}}}, year = {{2011}}, } @inproceedings{6886, author = {{Koch, S. and Kupke, J. and Tomow, D. and Schoppa, M. and Grunow, Paul and Krauter, Stefan}}, booktitle = {{Proceedings of the 26th European Photovoltaic Solar Energy Conference and Exhibition}}, title = {{{Polarisation Effects and Tests for Crystalline Silicon Cells}}}, year = {{2011}}, } @inproceedings{6887, author = {{Böttcher, A. and Horstmann, M. and Grunow, Paul and Pourhashemi, R. and Krauter, Stefan}}, booktitle = {{Proceedings of the 26th European Photovoltaic Solar Energy Conference and Exhibition}}, title = {{{Spectral Mismatch Correction for Micromorph Tandem Modules. }}}, year = {{2011}}, } @inproceedings{6888, author = {{Weber, T. and Albert, A. and Grunow, Paul and Krauter, Stefan}}, booktitle = {{Proceedings of the 26th European Photovoltaic Solar Energy Conference and Exhibition}}, title = {{{Electroluminescence Investigation on Thin Film Modules}}}, year = {{2011}}, } @inproceedings{16798, author = {{Ebert, Achim and Domik, Gitta and D. Gershon, Nahum and C. van der Veer, Gerrit}}, booktitle = {{Human-Computer Interaction - {INTERACT} 2011 - 13th {IFIP} {TC} 13 International Conference, Lisbon, Portugal, September 5-9, 2011, Proceedings, Part {IV}}}, editor = {{F. Campos, Pedro and C. Nicholas Graham, T. and A. Jorge, Joaquim and Jardim Nunes, Nuno and A. Palanque, Philippe and Winckler, Marco}}, pages = {{722--723}}, publisher = {{Springer}}, title = {{{Building Bridges - HCI and Visualization}}}, doi = {{10.1007/978-3-642-23768-3\_133}}, volume = {{6949}}, year = {{2011}}, } @article{15969, author = {{Lauter, Christian and Sarrazin, M. and Tröster, Thomas}}, journal = {{Adhäsion – Kleben und Dichten}}, pages = {{39--43}}, publisher = {{Springer Vieweg}}, title = {{{Multimaterialsysteme höchstfest verbunden}}}, volume = {{3/2011}}, year = {{2011}}, } @inproceedings{15971, author = {{Frantz, Meike and Stübbe, O. and Lauter, Christian and Schrange, J. and Tröster, Thomas}}, location = {{Köln}}, title = {{{Mechatronisches System zur Bestimmung der Restlebensdauer von Faserverbund-Leichtbaustrukturen am Beispiel einer Lauffeder}}}, year = {{2011}}, } @inproceedings{15972, author = {{Thomas, D. and Block, H. and Tröster, Thomas and Krogmeier, J.}}, location = {{Köln}}, title = {{{Herstellung von belastungsgerechten Strukturbauteilen mittels partieller induktiver Härtung}}}, year = {{2011}}, } @article{15974, author = {{Marten, Thorsten and Lauter, Christian and Tröster, Thomas}}, journal = {{Ingenieurspiegel}}, pages = {{67--69}}, publisher = {{Public Verlagsgesellschaft und Anzeigenagentur}}, title = {{{Automobilleichtbau durch höchstfeste Multimaterialsysteme}}}, volume = {{2/2011}}, year = {{2011}}, } @article{15975, author = {{Lauter, Christian and Thomas, D. and Frantz, Meike and Niewel, J. and Tröster, Thomas}}, journal = {{Werkstoffe in der Fertigung – Die Fachzeitschrift für technische Führungskräfte}}, pages = {{6--7}}, publisher = {{HW-Verlag}}, title = {{{Belastungsangepasste Strukturbauteile für Automobile aus höchstfesten Werkstoffen und Hybridwerkstoffen}}}, volume = {{2}}, year = {{2011}}, }