@inbook{4514, author = {{Jenert, Tobias and Zellweger, Franziska}}, booktitle = {{Kompetenzorientierte Hochschullehre: Die Notwendigkeit von Kohärenz zwischen Lernzielen, Prüfungsformen und Lehr-Lern-Methoden }}, isbn = {{978-3-0355-1084-3}}, pages = {{80--117}}, publisher = {{hep verlag ag }}, title = {{{Konsistente Gestaltung von Selbstlernumgebungen}}}, volume = {{1}}, year = {{2011}}, } @inbook{4515, author = {{Jenert, Tobias and Brahm, Taiga}}, booktitle = {{ Lehrbuch für Lernen und Lehren mit Technologien}}, editor = {{Ebner, Martin and Schön, Sandra}}, isbn = {{978-3842340114}}, pages = {{1--8}}, publisher = {{Books on Demand GmbH}}, title = {{{Planung und Organisation -Technologieeinsatz von der Bedarfsanalyse bis zur Evaluation}}}, year = {{2011}}, } @inbook{4524, author = {{Jenert, Tobias and Meier, Christoph and Brahm, Taiga}}, booktitle = {{Wissensgemeinschaften: Digitale Medien, Öffnung und Offenheit in Forschung und Lehre }}, editor = {{Köhler, Thomas and Neumann, Jörg}}, isbn = {{978-3-8309-2545-3}}, pages = {{136 -- 145}}, publisher = {{Waxmann Verlag GmbH }}, title = {{{QualiAss - ein Werkzeug zur Prozess- und Qualitätsunterstützung für schriftliche Prüfungen an Hochschulen : Nutzungsszenarien - Spezifikation - Einführung}}}, volume = {{60}}, year = {{2011}}, } @article{4544, abstract = {{The existence of localized vibrational modes both at the positive and at the negative LiNbO3 (0001) surface is demonstrated by means of first-principles calculations and Raman spectroscopy measurements. First, the phonon modes of the crystal bulk and of the (0001) surface are calculated within the density functional theory. In a second step, the Raman spectra of LiNbO3 bulk and of the two surfaces are measured. The phonon modes localized at the two surfaces are found to be substantially different, and are also found to differ from the bulk modes. The calculated and measured frequencies are in agreement within the error of the method. Raman spectroscopy is shown to be sensitive to differences between bulk and surface and between positive and negative surface. It represents therefore an alternative method to determine the surface polarity, which does not exploit the pyroelectric or piezoelectric properties of the material.}}, author = {{Sanna, S. and Berth, Gerhard and Hahn, W. and Widhalm, A. and Zrenner, Artur and Schmidt, W. G.}}, issn = {{0885-3010}}, journal = {{IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control}}, number = {{9}}, pages = {{1751--1756}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Vibrational properties of the LiNbO3 z-surfaces}}}, doi = {{10.1109/tuffc.2011.2012}}, volume = {{58}}, year = {{2011}}, } @article{4545, abstract = {{Laser irradiation damage in ZnTe epilayers was analyzed in situ by power-density-dependent and time-resolved micro-Raman spectroscopy. Damage by ablation or compound decomposition on the sample surface was revealed by the decrease of the ZnTe–nLO mode intensity with the increase of laser power density. The appearance of the peaks associated with the stronger crystalline-tellurium modes, tellurium aggregates and second-order Raman scattering at room temperature μ-Raman spectra was observed for higher power densities than 4.4 × 105 W cm−2. The Raman signal time transients of ZnTe–nLO and crystalline-tellurium modes reveal an exponential evolution of the laser irradiation damage and a fast formation of crystalline tellurium aggregates on the layer surface.}}, author = {{Wiedemeier, V and Berth, Gerhard and Zrenner, Artur and Larramendi, E M and Woggon, U and Lischka, K and Schikora, D}}, issn = {{0268-1242}}, journal = {{Semiconductor Science and Technology}}, number = {{10}}, publisher = {{IOP Publishing}}, title = {{{In situ characterization of ZnTe epilayer irradiation via time-resolved and power-density-dependent Raman spectroscopy}}}, doi = {{10.1088/0268-1242/26/10/105023}}, volume = {{26}}, year = {{2011}}, } @inproceedings{4546, abstract = {{Silicon oxynitride (SiON) layers for telecommunication device application are grown by Plasma Enhanced Chemical Vapor Deposition (PECVD) for various gas compositions of SiH4, N2O and NH3. Processing and annealing effects on the oxynitride films were studied by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM) measurements. By reduction of the silane (SiH4) gas flow and enhancement of the PECVD deposition temperature, the absorption loss due to NH bands can be nearly completely erased. Furthermore the surface roughness can be reduced by decreasing the gas flow and rising the deposition temperature. First waveguide structures are introduced and their characterization is presented.}}, author = {{Frers, Torsten and Hett, Thomas and Hilleringmann, Ulrich and Berth, Gerhard and Widhalm, Alex and Zrenner, Artur}}, booktitle = {{2011 Semiconductor Conference Dresden}}, isbn = {{9781457704314}}, location = {{Dresden, Germany}}, publisher = {{IEEE}}, title = {{{Characterization of SiON integrated waveguides via FTIR and AFM measurements}}}, doi = {{10.1109/scd.2011.6068744}}, year = {{2011}}, } @inbook{4559, abstract = {{Der Beitrag untersucht die Weblog-Arbeit Studierender zur Dokumenta¬tion und Reflexion von Praxisprojekten. Zu Beginn und nach Abschluss einer Lehrveranstaltung mit Praxisphase wurden Studierende zum Weblog-Arbeit befragt. Es zeigt sich, dass die Studierenden kaum über Erfahrungen in der Nutzung von Weblogs verfügen und überwiegend negative Einstellungen zum Bloggen aufweisen. Die Blogeinträge erreichen nicht die angestrebte Reflexionstiefe. Es wird diskutiert, wie das didaktische Design gestaltet werden kann, um die gewünschten Effekte - Peer-Feedback und tiefgehende Reflexion - zu erreichen.}}, author = {{Jenert, Tobias and Gebhardt , Anja}}, booktitle = {{Wissensgemeinschaften : Digitale Medien - Öffnung und Offenheit in Forschung und Lehre}}, editor = {{Köhler, Thomas and Neumann , Jörg}}, isbn = {{978-3-8309-2545-3}}, keywords = {{Weblogs, Selbststudium, Praxisprojekte, Hochschule, Edublog}}, pages = {{284--293}}, publisher = {{Waxmann Verlag GmbH }}, title = {{{Besseres Feedback, mehr Reflexion? – Fertigkeiten und Einstellungen Studierender zum Bloggen in Praxisprojekten}}}, volume = {{60}}, year = {{2011}}, } @article{4598, author = {{Guo, Zhichao and Feng, Yuanhua and Tan, Xiangyong}}, issn = {{0264-9993}}, journal = {{Economic Modelling}}, number = {{6}}, pages = {{2359--2368}}, publisher = {{Elsevier BV}}, title = {{{Short- and long-term impact of remarkable economic events on the growth causes of China–Germany trade in agri-food products}}}, doi = {{10.1016/j.econmod.2011.06.007}}, volume = {{28}}, year = {{2011}}, } @inproceedings{4707, author = {{Janiesch, Christian and Matzner, Martin and Müller, Oliver}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783642230585}}, issn = {{03029743}}, keywords = {{Reference architecture, business activity management, business process analytics, business process management, complex event processing}}, title = {{{A blueprint for event-driven business activity management}}}, doi = {{10.1007/978-3-642-23059-2_4}}, year = {{2011}}, } @article{4708, author = {{Müller-Wienbergen, Felix and Müller, Oliver and Seidel, Stefan and Becker, Jörg}}, isbn = {{1536-9323}}, issn = {{15369323}}, journal = {{Journal of the Association for Information Systems}}, keywords = {{Creativity, Creativity Support Systems, convergent thinking, design theory, divergent thinking}}, number = {{11}}, pages = {{714----740}}, title = {{{Leaving the Beaten Tracks in Creative Work – A Design Theory for Systems that Support Convergent and Divergent Thinking}}}, doi = {{10.1016/S0006-3495(00)76637-9}}, year = {{2011}}, } @article{4855, author = {{Garnefeld, Ina and Helm, Sabrina and Eggert, Andreas}}, journal = {{Journal of Service Research}}, number = {{1}}, pages = {{93----107}}, title = {{{Walk your talk: an experimental investigation of the relationship between word of mouth and communicators’ loyalty}}}, year = {{2011}}, } @article{4856, author = {{Eggert, Andreas and Hogreve, Jens and Ulaga, Wolfgang and Muenkhoff, Eva}}, journal = {{Industrial Marketing Management}}, number = {{5}}, pages = {{661----670}}, title = {{{Industrial services, product innovations, and firm profitability: A multiple-group latent growth curve analysis}}}, year = {{2011}}, } @article{4857, author = {{Eggert, Andreas and Serdaroglu, Murat}}, journal = {{Journal of Marketing Theory and Practice}}, number = {{2}}, pages = {{169----186}}, title = {{{Exploring the Impact of Sales Technology on Salesperson Performance: A Task-Base d Approach}}}, year = {{2011}}, } @article{4881, author = {{Fahr, Ren{\'e} and Irlenbusch, Bernd}}, journal = {{Journal of Economic Behavior \& Organization}}, number = {{1}}, pages = {{200----209}}, title = {{{Who follows the crowd—Groups or individuals?}}}, year = {{2011}}, } @article{4882, author = {{Fahr, Ren{\'e}}}, journal = {{management revue}}, pages = {{28----46}}, title = {{{Job design and job satisfaction—empirical evidence for Germany?}}}, year = {{2011}}, } @techreport{4918, author = {{Hinerasky, Christiane and Fahr, Rene}}, title = {{{When the early bird catches the worm: The impact of training in retail}}}, year = {{2011}}, } @inbook{4945, author = {{Ivens, Björn and Eggert, Andreas}}, booktitle = {{Handbuch Vertriebsmanagement}}, title = {{{Key Account Management}}}, year = {{2011}}, } @article{4972, author = {{Alewell, Dorothea and Hauff, Sven and Weiland, Katrin and Thommes, Kirsten}}, journal = {{International journal of manpower}}, number = {{4}}, pages = {{394----409}}, title = {{{HRM and the use of personnel services: an empirical analysis of German firms}}}, year = {{2011}}, } @article{4973, author = {{Braun, Irene and Pull, Kerstin and Alewell, Dorothea and Störmer, Susi and Thommes, Kirsten}}, issn = {{0048-3486}}, journal = {{Personnel Review}}, number = {{3}}, pages = {{364----382}}, title = {{{HR outsourcing and service quality: theoretical framework and empirical evidence}}}, volume = {{40}}, year = {{2011}}, } @article{6995, author = {{Beutner, Marc and Kremer, H.-Hugo and Zoyke, A. }}, journal = {{bwp@ Spezial 5 - Hochschultage Berufliche Bildung 2011}}, title = {{{Workshop 16 Individuelle Förderung. Konzepte und Erfahrungen zur Berufsorientierung im Übergang }}}, year = {{2011}}, } @misc{6999, booktitle = {{bwp@ Spezial 5 - Hochschultage Berufliche Bildung 2011}}, editor = {{Kremer, H.-Hugo and Tramm, T.}}, title = {{{Fachtagung 19}}}, year = {{2011}}, } @article{7049, author = {{Kremer, H.-Hugo and Tramm, T. and Tenberg, R.}}, journal = {{bwp@ Berufs- und Wirtschaftspädagogik - online}}, number = {{20}}, title = {{{Lernfeldansatz - 15 Jahre danach}}}, year = {{2011}}, } @article{7311, author = {{Soldat, Henning and Li, Mingyuan and Gerhardt, Nils C. and Hofmann, Martin R. and Ludwig, Arne and Ebbing, Astrid and Reuter, Dirk and Wieck, Andreas D. and Stromberg, Frank and Keune, Werner and Wende, Heiko}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{5}}, publisher = {{AIP Publishing}}, title = {{{Room temperature spin relaxation length in spin light-emitting diodes}}}, doi = {{10.1063/1.3622662}}, volume = {{99}}, year = {{2011}}, } @article{7335, author = {{Krenner, Hubert J. and Völk, Stefan and Schülein, Florian J. R. and Knall, Florian and Wixforth, Achim and Reuter, Dirk and Wieck, Andreas D. and Kim, Hyochul and Truong, Tuan A. and Petroff, Pierre M.}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, number = {{2}}, pages = {{407--410}}, publisher = {{Wiley}}, title = {{{Surface acoustic wave controlled carrier injection into self-assembled quantum dots and quantum posts}}}, doi = {{10.1002/pssc.201100236}}, volume = {{9}}, year = {{2011}}, } @article{7353, abstract = {{Manuelle Testerstellung verursacht hohe Kosten. Im Vergleich dazu bietet modellbasiertes Testen große Vorteile hinsichtlich Testautomatisierung, früher Fehlerfindung, Erhöhung der Testabdeckung, effizienten Testentwurfs und besserer Rückverfolgbarkeit. Die Einführung des modellbasierten Testens ist jedoch mit Investitionen verbunden, für die die Rendite häufig unklar erscheint. Dabei finden sich in der Literatur bereits etliche Erfahrungsberichte zur erfolg­reichen Einführung von modellbasiertem Testen in unterschiedlichen Anwendungsdomänen. In diesem Artikel präsentieren wir einen Überblick über einige dieser Erfahrungsberichte.}}, author = {{Weißleder, Stephan and Güldali, Baris and Mlynarski, Michael and Törsel, Arne-Michael and Faragó, David and Prester, Florian and Winter, Mario}}, journal = {{OBJEKTspektrum}}, number = {{6}}, pages = {{59--65}}, title = {{{Modellbasiertes Testen: Hype oder Realität?}}}, year = {{2011}}, } @article{7354, abstract = {{Acceptance testing is a time-consuming task for complex software systems that have to fulfill a large number of requirements. To reduce this effort, we have developed a widely automated method for deriving test plans from requirements that are expressed in natural language. It consists of three stages: annotation, clustering, and test plan specification. The general idea is to exploit redundancies and implicit relationships in requirements specifications. Multi-viewpoint techniques based on RM-ODP (Reference Model for Open Distributed Processing) are employed for specifying the requirements. We then use linguistic analysis techniques, requirements clustering algorithms, and pattern-based requirements collection to reduce the total effort of testing against the requirements specification. In particular, we use linguistic analysis for extracting and annotating the actor, process and object of a requirements statement. During clustering, a similarity function is computed as a measure for the overlap of requirements. In the test plan specification stage, our approach provides capabilities for semi-automatically deriving test plans and acceptance criteria from the clustered informal textual requirements. Two patterns are applied to compute a suitable order of test activities. The generated test plans consist of a sequence of test steps and asserts that are executed or checked in the given order. We also present the supporting prototype tool TORC, which is available open source. For the evaluation of the approach, we have conducted a case study in the field of acceptance testing of a national electronic identification system. In summary, we report on lessons learned how linguistic analysis and clustering techniques can help testers in understanding the relations between requirements and for improving test planning.}}, author = {{Güldali, Baris and Funke, Holger and Sauer, Stefan and Engels, Gregor}}, issn = {{0963-9314}}, journal = {{Software Quality Journal}}, number = {{4}}, pages = {{771--799}}, publisher = {{Springer Nature}}, title = {{{TORC: test plan optimization by requirements clustering}}}, doi = {{10.1007/s11219-011-9149-4}}, volume = {{19}}, year = {{2011}}, } @article{7355, abstract = {{Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at languages based on a metamodel. A DMM specification consists of a runtime metamodel and operational rules which describe how instances of the runtime metamodel change over time. A known deficiency of the DMM approach is that it does not support the refinement of a DMM specification, e.g., in the case of defining the semantics for a refined and extended domain-specific language (DSL). Up to now, DMM specifications could only be reused by adding or removing DMM rules. In this paper, we enhance DMM such that DMM rules can override other DMM rules, similar to a method being overridden in a subclass, and we show how rule overriding can be realized with the graph transformation tool GROOVE. We argue that rule overriding does not only have positive impact on reusability, but also improves the intuitive understandability of DMM semantics specifications.}}, author = {{Soltenborn, Christian and Engels, Gregor}}, issn = {{1045-926X}}, journal = {{Journal of Visual Languages & Computing}}, number = {{3}}, pages = {{233--250}}, publisher = {{Elsevier BV}}, title = {{{Using rule overriding to improve reusability and understandability of Dynamic Meta Modeling specifications}}}, doi = {{10.1016/j.jvlc.2010.12.005}}, volume = {{22}}, year = {{2011}}, } @article{7476, author = {{Kremer, H.-Hugo and Frehe, Petra}}, journal = {{Beilage Schule NRW}}, number = {{05/11}}, pages = {{4--8}}, title = {{{Individuelle Förderung - aber wie? Einblicke in das Innovationsprojekt InLab}}}, year = {{2011}}, } @article{7477, author = {{Sloane, Peter F. E. and Kremer, H.-Hugo}}, journal = {{Beilage Schule NRW}}, number = {{05/11}}, pages = {{4--8}}, title = {{{Individuelle Förderung fördern. Das Wirtschaftspädagogische Graduiertenkolleg als Innovation in der Lehrkräfte- und Schulentwicklung}}}, year = {{2011}}, } @article{7483, author = {{Kremer, H.-Hugo and Sandmann, D.}}, journal = {{bwp@ Berufs- und Wirtschaftspädagogik - online}}, title = {{{Kooperationsvorhaben berufliches Gymnasium und Bachelor Wirtschaftswissenschaften. Ein Paderborner Modellprojekt zur Berufs- und Studienorientierung}}}, year = {{2011}}, } @inproceedings{7535, author = {{Böckelmann, Irina and Schenk, Daniel and Rößler, Thoralf and Adler, Simon and Senft, Björn and Grubert, Jens and Mecke, Rüdiger and Huckauf, Anke and Urbina, Mario and Tümler, Johannes and Darius, Sabine}}, title = {{{Physiologische Beanspruchungsreaktionen bei der Anwendung von kopfgetragenen AR-Displays}}}, year = {{2011}}, } @inproceedings{7536, author = {{Klompmaker, Florian and Senft, Björn and Nebe, Karsten and Busch, Clemens and Willemsen, Detlev}}, booktitle = {{{HEALTHINF} 2011 - Proceedings of the International Conference on Health Informatics, Rome, Italy, 26-29 January, 2011}}, pages = {{268--273}}, title = {{{User Centered Design Process of OSAMi-D - Developing User Interfaces for a Remote Ergometer Training Application}}}, year = {{2011}}, } @article{7604, author = {{Kremer, H.-Hugo and Tramm, T.}}, journal = {{bwp@ Berufs- und Wirtschaftspädagogik - online}}, title = {{{Berufliche Bildung 2011, Fachtagung 19}}}, year = {{2011}}, } @inproceedings{8348, author = {{Krauter, Stefan}}, booktitle = {{ Proceedings of Decentralized Power Systems (DPS) 2011, Paderborn (Deutschland), 2. September 2011.}}, title = {{{The Challenge of Renewable Energies & Decentralized Power Systems – State of the Art, Potentials & Perspectives}}}, year = {{2011}}, } @inproceedings{8471, abstract = {{Performance is an important quality attribute for business information systems. When a tester has spotted a performance error, the error is passed to the software developers to fix it. However, in component-based software development the tester has to do blame analysis first, i. e. the tester has to decide, which party is responsible to fix the error. If the error is a design or deployment issue, it can be assigned to the software architect or the system deployer. If the error is specific to a component, it needs to be assigned to the corresponding component developer. An accurate blame analysis is important, because wrong assignments of errors will cause a loss of time and money. Our approach aims at doing blame analysis for performance errors by comparing performance metrics obtained in performance testing and performance prediction. We use performance prediction values as expected values for individual components. For performance prediction we use the Palladio approach. By this means, our approach evaluates each component’s performance in a certain test case. If the component performs poorly, its component developer needs to fix the component or the architect replaces the component with a faster one. If no omponent performs poorly, we can deduce that there is a design or deployment issue and the architecture needs to be changed. In this paper, we present an exemplary blame analysis based on a web shop system. The example shows the feasibility of our approach.}}, author = {{Brüseke, Frank and Becker, Steffen and Engels, Gregor}}, booktitle = {{Proceedings of the 16th International Workshop on Component-Oriented Programming (WCOP; satellite event of the CompArch 2011), Boulder Colorado, CO (USA)}}, pages = {{25--32}}, publisher = {{ACM}}, title = {{{Palladio-based performance blame analysis}}}, doi = {{http://dx.doi.org/10.1145/2000292.2000298}}, year = {{2011}}, } @inproceedings{8472, author = {{Nagel, Benjamin }}, booktitle = {{Proceedings of the Software Engineering 2011 (SE 2011), Karlsruhe (Germany)}}, publisher = {{Gesellschaft für Informatik (GI)}}, title = {{{Semi-automatische Ableitung externer Anpassungsmechanismen für selbst-adaptive Systeme}}}, year = {{2011}}, } @misc{8841, author = {{Jovanovikj, Ivan}}, title = {{{Search on Semi-Structured Data using Lucene Search Engine}}}, year = {{2011}}, } @inbook{9589, author = {{Beutner, Marc}}, booktitle = {{Lehrerbildung phasenübergreifend denken. Facetten einer bundesweiten Debatte}}, editor = {{Häcker, Th and Bartel, K and Peters, K}}, pages = {{140 -- 158}}, title = {{{Kompetenzbegriff und Evaluation im beruflichen Bildungswesen}}}, year = {{2011}}, } @inbook{9726, author = {{Flotmann, Christina and Tönnies, Merle}}, booktitle = {{Narrative in Drama: CDE Studies 18}}, editor = {{Tönnies, Merle and Flotmann-Scholz, Christina}}, pages = {{9--17}}, publisher = {{WVT}}, title = {{{Introducing Narrative in Drama}}}, volume = {{18}}, year = {{2011}}, } @article{9765, abstract = {{The multi-objective optimal design of a piezoelectric sandwich ultrasonic transducer is studied. The maximum vibration amplitude and the minimum electrical input power are considered as optimization objectives. Design variables involve continuous variables (dimensions of the transducer) and discrete variables (material types). Based on analytical models, the optimal design is formulated as a constrained multi-objective optimization problem. The optimization problem is then solved by using the elitist non-dominated sorting genetic algorithm (NSGA-II) and Pareto-optimal designs are obtained. The optimized results are analyzed and the preferred design is proposed. The optimization procedure presented in this contribution can be applied in multi-objective optimization problems of other piezoelectric transducers.}}, author = {{Hemsel, Tobias and Fu, Bo and Jing, Yi and Fu, Xuan}}, journal = {{Key Engineering Materials}}, pages = {{1808--1812}}, publisher = {{Trans Tech Publ}}, title = {{{Multi-Objective Optimization of a Piezoelectric Sandwich Ultrasonic Transducer by Using Elitist Non-Dominated Sorting Genetic Algorithm}}}, doi = {{10.4028/www.scientific.net/KEM.474-476.1808}}, volume = {{474 - 476}}, 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}}, } @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}}, } @book{9918, editor = {{Tönnies, Merle and Flotmann, Christina}}, publisher = {{WVT}}, title = {{{Narrative in Drama}}}, year = {{2011}}, } @article{4089, abstract = {{We study the influence of the phonon environment on the electron dynamics in a doped quantum dot molecule. A non-perturbative quantumkinetic theory based on correlation expansion is used in order to describe both diagonal and off-diagonal electron-phonon couplings representing real and virtual processes with relevant acoustic phonons. We show that the relaxation is dominated by phononassisted electron tunneling between constituent quantum dots and occurs on a picosecond time scale. The dependence of the time evolution of the quantum dot occupation probabilities on the energy mismatch between the quantum dots is studied in detail.}}, author = {{Grodecka-Grad, Anna and Förstner, Jens}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, keywords = {{tet_topic_qd}}, number = {{4}}, pages = {{1125--1128}}, publisher = {{Wiley}}, title = {{{Phonon-assisted decoherence and tunneling in quantum dot molecules}}}, doi = {{10.1002/pssc.201000824}}, volume = {{8}}, year = {{2011}}, } @article{4140, abstract = {{In this paper we report on the successful reduction of tensile strain in a thin strained ion-beam synthesized 3C-SiC(1 1 1) layer on silicon. The creation of a near-interface defect structure consisting of nanometric voids and stacking fault type defects by He ion implantation and subsequent annealing yields significant relaxation in the top SiC film. The microstructure of the defect layer is studied by transmission electron microscopy, and the strain state of the 3C-SiC layer was studied by high-resolution X-ray diffraction in a parallel beam configuration. Typical process conditions for the growth of GaN films on the SiC layer were emulated by high temperature treatments in a rapid thermal annealer or a quartz tube furnace. It is found that prolonged annealing at high temperatures leads to ripening of the voids and to a weaker reduction of the tensile strain. It is shown that this problem can be overcome by the co-implantation of oxygen ions to form highly thermally stable void/extended defect structures.}}, author = {{Häberlen, M. and Murphy, B. and Stritzker, B. and Lindner, Jörg}}, issn = {{0168-583X}}, journal = {{Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms}}, pages = {{322--325}}, publisher = {{Elsevier BV}}, title = {{{Relaxation of a strained 3C-SiC(111) thin film on silicon by He+ and O+ ion beam defect engineering}}}, doi = {{10.1016/j.nimb.2011.01.092}}, volume = {{272}}, year = {{2011}}, }