@article{9808, abstract = {{This study presents the methods employed by a team from the department of Mechatronics and Dynamics at the University of Paderborn, Germany for the 2013 PHM data challenge. The focus of the challenge was on maintenance action recommendation for an industrial machinery based on remote monitoring and diagnosis. Since an ensemble of data driven methods has been considered as the state of the art approach in diagnosis and prognosis, the first approach was to evaluate the performance of an ensemble of data driven methods using the parametric data as input and problems (recommended maintenance action) as the output. Due to close correlation of parametric data of different problems, this approach produced high misclassification rate. Event-based decision trees were then constructed to identify problems associated with particular events. To distinguish between problems associated with events that appeared in multiple problems, support vector machine (SVM) with parameters optimally tuned using particle swarm optimization (PSO) was employed. Parametric data was used as the input to the SVM algorithm and majority voting was employed to determine the final decision for cases with multiple events. A total of 165 SVM models were constructed. This approach improved the overall score from 21 to 48. The method was further enhanced by employing an ensemble of three data driven methods, that is, SVM, random forests (RF) and bagged trees (BT), to build the event based models. With this approach, a score of 51 was obtained . The results demonstrate that the proposed event based method can be effective in maintenance action recommendation based on events codes and parametric data acquired remotely from an industrial equipment.}}, author = {{Kimotho, James Kuria and Sondermann-Wölke, Chritoph and Meyer, Tobias and Sextro, Walter}}, journal = {{International Journal of Prognostics and Health Management}}, keywords = {{maintenance decision, Bagged trees, Decision trees, PSO-SVM, Random forests}}, number = {{2}}, title = {{{Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation}}}, volume = {{4}}, year = {{2013}}, } @article{9819, author = {{Herzig, Bardo and Klar, Tilman-Mathies}}, journal = {{Lernende Schule - Medienkompetenz entwickeln}}, number = {{64}}, pages = {{7--11}}, title = {{{Grundlagen medienbezogener Schulentwicklung}}}, 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}}, } @inproceedings{9856, author = {{Lenzen, Marco and Unger, Andreas and Wortberg, Johannes}}, publisher = {{SPE Antec}}, title = {{{2PC-Recu-Module for energy recovery at hydraulic driven injection molding machines}}}, year = {{2013}}, } @inproceedings{9858, abstract = {{In this contribution, we introduce a multiobjective optimization used to calculate safe optimal working points for a mechatronic system by including stochastic safety-critical signals in an objective function. Our application example consists of a linear drive for a rail-bound vehicle and an actuation unit. The linear drive's secondary part is fixed; the primary part is vehicle-mounted and can be adjusted vertically to account for deviations of the height of the secondary part. A small air gap between both parts improves efficiency, but increases the risk of a collision between the two parts. Using height data of the secondary part, a trajectory for the vertical adjustment of the primary part is calculated. However, unexpected deviations necessitate a readjustment of the air gap. The probability of such unexpected height deviations can be calculated from the readjustment data. The system is equipped with sensors to measure the air gap. Assuming that the sensor noise is normally distributed, noise characteristics are determined. Using this information and the probability distribution of unexpected height deviations, the probability of a collision is determined.T he sensor noise and the probability of a collision between both parts of the linear drive are included in the dynamical model of the system. Using multiobjective optimization, pareto-optimal working points for the controller of the air gap are obtained. By selecting an appropriate working point, safe operation can be ensured.}}, author = {{Meyer, Tobias and Hölscher, Christina and Menke, Michael and Sextro, Walter and Zimmer, Detmar}}, booktitle = {{Proc. Appl. Math. Mech.}}, pages = {{483--484}}, title = {{{Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System}}}, doi = {{10.1002/pamm.201310234}}, volume = {{13}}, year = {{2013}}, } @inproceedings{9859, abstract = {{Self-optimizing mechatronic systems allow the adaptation of the system's behavior to the current situation. This can be used to actively adapt the behavior to the current degradation state of the system or of some of its components. To this end, the Multi-Level Dependability Concept has been developed. In this contribution, we show how the Multi-Level Dependability Concept has been applied to the active suspension module of an innovative rail-bound vehicle. For this module, the usage of control reconfiguration, which is a novel approach to exploit complex redundancy systems, is required. We show that by combining self-optimization with the possibilities given by control reconfiguration, the dependability of a complex mechatronic system can be greatly improved.}}, author = {{Meyer , Tobias and Henning Keßler, Jan and Sextro, Walter and Trächtler, Ansgar}}, booktitle = {{Proceedings of the Annual Reliability and Maintainability Symposium (RAMS)}}, title = {{{Increasing Intelligent Systems' Reliability by Using Reconfiguration}}}, doi = {{10.1109/RAMS.2013.6517636}}, year = {{2013}}, } @article{9860, abstract = {{Self-optimizing mechatronic systems offer possibilities well beyond those of traditional mechatronic systems. Among these is the adaptation of the system behavior to the current situation. To do so, they are able to choose from different working points, which are pre-calculated using multiobjective optimization and are thus Pareto-optimal with regard to the chosen objective functions. In this contribution, a method is presented that allows to continuously control the system degradation by adapting the behavior of a selfoptimizing system throughout its complete lifetime. The current remaining useful lifetime is estimated and then related to the spent lifetime and the desired useful lifetime. Using this information, a reliability-related objective is prioritized using a closed-loop control, which in turn is used to determine the working point of the self-optimizing system. This way, the desired useful lifetime can be achieved. To exemplify the setup of the controller structure and to demonstrate the adaptation of the system behavior, a dynamic model of a clutch system is used. It can be seen that the closed loop controller is able to correct for external perturbations, such as changed requirements, as well as changed system parameters. This way, the modeled system is able to achieve the desired lifetime reliably.}}, author = {{Meyer, Tobias and Sondermann-Wölke, Christoph and Kimotho, James Kuria and Sextro, Walter}}, journal = {{Chemical Engineering Transactions}}, pages = {{625--630}}, title = {{{Controlling the Remaining Useful Lifetime using Self-Optimization}}}, doi = {{10.3303/CET1333105}}, volume = {{33}}, year = {{2013}}, } @inproceedings{9861, abstract = {{Selbstoptimierende mechatronische Systeme bieten die Möglichkeit, ihr Verhalten an geänderte Umgebungsbedingungen anzupassen. Dazu werden beispielsweise redundante Strukturen genutzt, Reglerparameter angepasst oder Regelstrategien umgeschaltet. Dies kann auch genutzt werden, um die Zuverlässigkeit des Systems zu steigern. Zugleich entstehen aber durch die gesteigerte Komplexität dieser Systeme zusätzliche Risiken. Um sicherzustellen, dass das System dennoch die gestellten Anforderungen bezüglich der Zuverlässigkeit erfüllt, ist eine Modellierung des Gesamtsystems und anschließende Zuverlässigkeitsbewertung notwendig. Dies ist aufgrund der situationsabhängigen Verhaltensanpassung und des nicht intuitiv vorhersehbaren Verhaltens jedoch nicht mit klassischen Verfahren möglich. Ein Modellierungsverfahren, das diese Eigenschaften abbilden kann, ist LARES (LAnguage for REconfigurable dependable Systems). Die Anwendung von LARES zur Bewertung der Zuverlässigkeit eines selbstoptimierenden Systems wird anhand des Feder-Neige-Moduls gezeigt. Es ist eine Baugruppe der Fahrzeuge eines innovativen Bahnsystems, der RailCabs. Das Feder-Neige-Modul dient dazu, unerwünschte Schwingungen des Fahrzeugaufbaus zu minimieren. Mit LARES können die Hardware-Komponenten des Systems, ihre in Abhängigkeit von der aktuellen Situation veränderten Belastungen sowie die nicht-deterministische Verhaltensadaption modelliert werden.}}, author = {{Meyer, Tobias and Sondermann-Wölke, Christoph and Sextro, Walter and Riedl, Martin and Gouberman, Alexander and Siegle, Markus}}, booktitle = {{9. Paderborner Workshop Entwurf mechatronischer Systeme}}, editor = {{Gausemeier, Jürgen and Dumitrescu, Roman and Rammig, Franz and Schäfer, Wilhelm and Trächtler, Ansgar}}, pages = {{161--174}}, publisher = {{Heinz Nixdorf Institut, Universität Paderborn}}, title = {{{Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework}}}, 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}}, } @article{9866, abstract = {{The hydrothermal method utilizes a solution-based chemical reaction to synthesize piezoelectric thin films and powders. This method has a number of advantages, such as low-temperature synthesis, and high purity and high quality of the product. In order to promote hydrothermal reactions, we developed an ultrasonic assisted hydrothermal method and confirmed that it produces dense and thick lead--zirconate--titanate (PZT) films. In the hydrothermal method, a crystal growth process follows the nucleation process. In this study, we verified that ultrasonic irradiation is effective for the nucleation process, and there is an optimum irradiation period to obtain thicker PZT films. With this optimization, a 9.2-$\mu$ m-thick PZT polycrystalline film was obtained in a single deposition process. For this film, ultrasonic irradiation was carried out from the beginning of the reaction for 18 h, followed by a 6 h deposition without ultrasonic irradiation. These results indicate that the ultrasonic irradiation mainly promotes the nucleation process.}}, author = {{Ohta, Kanako and Isobe, Gaku and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, issn = {{0041-624X}}, journal = {{Ultrasonics}}, keywords = {{Piezoelectric material}}, number = {{4}}, pages = {{837 -- 841}}, title = {{{Study on optimizing ultrasonic irradiation period for thick polycrystalline PZT film by hydrothermal method}}}, doi = {{10.1016/j.ultras.2012.12.003}}, volume = {{53}}, year = {{2013}}, } @article{9867, abstract = {{We report the piezoelectric properties of CuO-doped hydrothermal (K,Na)NbO3 ceramics that can be applied as hard-type lead-free piezoelectric ceramics. To date, we have succeeded in synthesizing high-quality KNbO3 and NaNbO3 powders by the hydrothermal method, which is based on an ionic reaction at high temperature (around 210 $\,^{\circ}$C) and pressure. Increasing both the piezoelectric constant d and the mechanical quality factor (Qm) is important for resonance-type piezoelectric devices, such as ultrasonic motors and transformers. CuO doping into hydrothermal (K,Na)NbO3 ceramics was examined to realize hard-type lead-free piezoelectric ceramics. By doping with 1.2 mol \% CuO, Qm was increased and the dielectric loss (tan δ) was decreased to 0.5\%. The grain size was also influenced by the amount of CuO doping, which indicates that Qm is related to the density. To achieve a higher Qm value, the grain size is required to be less than 5 µm; however, excessive CuO doping leads to anomalous grain growth. Optimal piezoelectric properties were obtained for 1.2 mol \% CuO-doped (K,Na)NbO3; k31 = 0.32, d31 = -44 pC/N, Qm (radial) = 959, and tan δ= 0.5\%. These characteristics showed that CuO doping with hydrothermal powders is effective for obtaining hard-type ceramics, and the mechanical quality factor is more than ten times higher than that of nondoped hydrothermal (K,Na)NbO3 ceramics. Therefore, compared with the conventional solid-state method, we could succeed in obtaining hard-type ceramics by a simple and short process.}}, author = {{Yokouchi, Yuriko and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, journal = {{Japanese Journal of Applied Physics}}, number = {{7S}}, title = {{{Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders}}}, doi = {{10.7567/JJAP.52.07HB03}}, volume = {{52}}, year = {{2013}}, } @article{3959, abstract = {{Microresonators containing quantum dots find application in devices like single photon emitters for quantum information technology as well as low threshold laser devices. We demonstrate the fabrication of 60 nm thin zinc-blende AlN microdisks including cubic GaN quantum dots using dry chemical etching techniques. Scanning electron microscopy analysis reveals the morphology with smooth surfaces of the microdisks. Micro-photoluminescence measurements exhibit optically active quantum dots. Furthermore this is the first report of resonator modes in the emission spectrum of a cubic AlN microdisk.}}, author = {{Bürger, M. and Kemper, R.M. and Bader, C.A. and Ruth, M. and Declair, S. and Meier, Cedrik and Förstner, Jens and As, D.J.}}, issn = {{0022-0248}}, journal = {{Journal of Crystal Growth}}, keywords = {{tet_topic_qd, tet_topic_microdisk}}, pages = {{287--290}}, publisher = {{Elsevier BV}}, title = {{{Cubic GaN quantum dots embedded in zinc-blende AlN microdisks}}}, doi = {{10.1016/j.jcrysgro.2012.12.058}}, volume = {{378}}, year = {{2013}}, } @article{3963, abstract = {{Whispering gallery modes (WGMs) were observed in 60 nm thin cubic AlN microdisk resonators containing a single layer of non-polar cubic GaN quantum dots. Freestanding microdisks were patterned by means of electron beam lithography and a two step reactive ion etching process. Micro-photoluminescence spectroscopy investigations were performed for optical characterization. We analyzed the mode spacing for disk diameters ranging from 2-4 lm. Numerical investigations using three dimensional finite difference time domain calculations were in good agreement with the experimental data. Whispering gallery modes of the radial orders 1 and 2 were identified by means of simulated mode field distributions.}}, author = {{Bürger, M. and Ruth, M. and Declair, S. and Förstner, Jens and Meier, Cedrik and As, Donat Josef}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, keywords = {{tet_topic_qd, tet_topic_microdisk}}, number = {{8}}, pages = {{081105}}, publisher = {{AIP Publishing}}, title = {{{Whispering gallery modes in zinc-blende AlN microdisks containing non-polar GaN quantum dots}}}, doi = {{10.1063/1.4793653}}, volume = {{102}}, year = {{2013}}, } @article{3976, author = {{Bauhoff, Frauke and Schneider, Martin}}, journal = {{Industrielle Beziehungen/The German Journal of Industrial Relations}}, pages = {{54----76}}, title = {{{„Sekret{\"a}rin des Vorstandes “gesucht: Stellenanzeigen und die expressive Funktion des AGG}}}, year = {{2013}}, } @article{3979, author = {{Bauhoff, Frauke and Schneider, Martin}}, journal = {{Industrielle Beziehungen/The German Journal of Industrial Relations}}, pages = {{54----76}}, title = {{{„Sekretärin des Vorstandes“ gesucht: Stellenanzeigen und die expressive Funktion des AGG}}}, year = {{2013}}, } @inbook{4094, author = {{Kemper, R.M. and As, Donald and Lindner, Jörg}}, booktitle = {{Silicon-based Nanomaterials}}, editor = {{Li, H. and Wu, J. and Wang, Z.M.}}, isbn = {{978-1-4614-8168-3}}, pages = {{381--405}}, publisher = {{Springer Series in Materials Science}}, title = {{{Cubic GaN on nano-patterned 3C-SiC/Si (001) substrates}}}, volume = {{187}}, year = {{2013}}, } @inproceedings{4097, author = {{Brassat, Katharina and Pauly, Johannes and Kemper, R. and Strake, M. and Brodehl, Christoph and Sievers, Werner and Riedl, Thomas and Lindner, Jörg}}, location = {{Paderborn}}, title = {{{Colloidal nano-lithography: state-of-the-art}}}, year = {{2013}}, } @article{4098, abstract = {{The selective deposition and self-assembly of nanospheres from a colloidal suspension in trenches on silicon surfaces is investigated using conventional light, confocal laser scanning and scanning electron microscopy. Trenches with widths of one to several nanosphere diameters are formed on silicon surfaces by photolithography and reactive ion etching. The spreading knife convective self-assembly technique is employed to distribute the nanosphere suspension on the pre-patterned surface. It is shown that this technique is particularly useful in combination with a functionalized surface where a selfassembled molecular monolayer changes the contact angle such that sphere deposition takes place almost exclusively in the trenches. By this, lines selectively filled with a chain of beads with a length of 0.5 mm have been achieved.}}, author = {{Brassat, Katharina and Assion, Fabian and Hilleringmann, Ulrich and Lindner, Jörg}}, issn = {{1862-6300}}, journal = {{physica status solidi (a)}}, location = {{Warsaw (Poland)}}, number = {{8}}, pages = {{1485--1489}}, publisher = {{Wiley}}, title = {{{Self-organization of nanospheres in trenches on silicon surfaces}}}, doi = {{10.1002/pssa.201200899}}, volume = {{210}}, year = {{2013}}, } @inproceedings{4100, author = {{Brassat, Katharina and Lindner, Jörg}}, location = {{Regensburg}}, title = {{{Selective deposition of nanospheres in trenches on silicon surfaces by self-organisation}}}, year = {{2013}}, } @inproceedings{4101, author = {{Brodehl, Christoph and Greulich-Weber, Siegmund and Lindner, Jörg}}, location = {{Paderborn}}, title = {{{Tailored structures produced via nanosphere lithography}}}, year = {{2013}}, }