@article{8607, author = {{Hohage, P. E. and Nannen, J. and Halm, S. and Bacher, G. and Wahle, M. and Fischer, S. F. and Kunze, U. and Reuter, Dirk and Wieck, A. D.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, title = {{{Coherent spin dynamics in Permalloy-GaAs hybrids at room temperature}}}, doi = {{10.1063/1.2943279}}, year = {{2008}}, } @article{8608, author = {{Hövel, S. and Gerhardt, N. C. and Hofmann, M. R. and Lo, F.-Y. and Reuter, Dirk and Wieck, A. D. and Schuster, E. and Keune, W. and Wende, H. and Petracic, O. and Westerholt, K.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, title = {{{Electrical detection of photoinduced spins both at room temperature and in remanence}}}, doi = {{10.1063/1.2948856}}, year = {{2008}}, } @article{8609, author = {{Hövel, S. and Gerhardt, N. C. and Hofmann, M. R. and Lo, F.-Y. and Ludwig, A. and Reuter, Dirk and Wieck, A. D. and Schuster, E. and Wende, H. and Keune, W. and Petracic, O. and Westerholt, K.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, title = {{{Room temperature electrical spin injection in remanence}}}, doi = {{10.1063/1.2957469}}, year = {{2008}}, } @article{8610, author = {{Koop, E. J. and van Wees, B. J. and Reuter, Dirk and Wieck, A. D. and van der Wal, C. H.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, title = {{{Spin Accumulation and Spin Relaxation in a Large Open Quantum Dot}}}, doi = {{10.1103/physrevlett.101.056602}}, year = {{2008}}, } @article{8611, author = {{Hugger, S. and Xu, Hengyi and Tarasov, A. and Cerchez, M. and Heinzel, T. and Zozoulenko, I. V. and Reuter, Dirk and Wieck, A. D.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, title = {{{Magnetic-barrier-induced conductance fluctuations in quantum wires}}}, doi = {{10.1103/physrevb.78.165307}}, year = {{2008}}, } @article{8612, author = {{Rizo, P. J. and Pugžlys, A. and Liu, J. and Reuter, Dirk and Wieck, A. D. and van der Wal, C. H. and van Loosdrecht, P. H. M.}}, issn = {{0034-6748}}, journal = {{Review of Scientific Instruments}}, title = {{{Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures}}}, doi = {{10.1063/1.3046283}}, year = {{2008}}, } @article{8613, author = {{Komijani, Y. and Csontos, M. and Ihn, T. and Ensslin, K. and Reuter, Dirk and Wieck, A. D.}}, issn = {{0295-5075}}, journal = {{EPL (Europhysics Letters)}}, title = {{{Observation of excited states in a p-type GaAs quantum dot}}}, doi = {{10.1209/0295-5075/84/57004}}, year = {{2008}}, } @article{8616, author = {{Kaiser, F J and Kohler, S and Hänggi, P and Malecha, M and Ebbecke, J and Wixforth, A and Schumacher, H W and Kästner, B and Reuter, Dirk and Wieck, A D}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, title = {{{Theoretical and experimental investigations of Coulomb blockade in coupled quantum dot systems}}}, doi = {{10.1088/0953-8984/20/37/374108}}, year = {{2008}}, } @article{8617, author = {{Hernandez, F. G. G. and Greilich, A. and Brito, F. and Wiemann, M. and Yakovlev, D. R. and Reuter, Dirk and Wieck, A. D. and Bayer, M.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, title = {{{Temperature-induced spin-coherence dissipation in quantum dots}}}, doi = {{10.1103/physrevb.78.041303}}, year = {{2008}}, } @article{8618, author = {{Scheibner, R and König, M and Reuter, Dirk and Wieck, A D and Gould, C and Buhmann, H and Molenkamp, L W}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, title = {{{Quantum dot as thermal rectifier}}}, doi = {{10.1088/1367-2630/10/8/083016}}, year = {{2008}}, } @inproceedings{9573, abstract = {{Integrating dependability in self-optimizing systems is a challenging task. Self-optimizing systems incorporate on the one hand the opportunity to apply novel solutions to complex mechatronic systems, but on the other hand constitute a possible risk because of non-determined behavior. The dependability concept in this paper covers both aspects: Increasing safety with selfoptimization and minimizing the risk of self-optimization. This dependability concept is combined with the self-optimization process of the active guidance module which is currently under development at the Collaborative Research Center 614 at the University of Paderborn.}}, author = {{Sondermann-Wölke, Christoph and Geisler, Jens and Müler, Thomas and Trächtler, Ansgar and Böcker, Joachim}}, booktitle = {{ASME 2008 -- International Design Engineering Technical Conferences \& Computers and Information in Engineering Conference (IDETC/CIE)}}, title = {{{The active guidance module of a rail-bound vehicle as an application for the dependability oriented design in self-optimizing systems}}}, year = {{2008}}, } @article{9574, abstract = {{For devices having non-linear contact, load plays a fundamental role. Variations in the characteristics of the load cause change in eigenfrequency and amplitude of the vibration. In most technical applications, this unwanted behaviour is cancelled by the use of control algorithms. However, multiple applications, like bond quality monitoring or chemical and pressure sensors, have found that the load may be characterised by interpreting the change in characteristics of a resonant vibrating device used as a sensor. Surgical resection of tumours is a very difficult task. After localising the tumour by the use of imaging techniques, the resection demands the surgeon to decide where and what to resect based on visual and tactile differentiation of tumour and healthy tissue. Exactness of this process could be enhanced if we can provide the surgeon with a device capable of evaluating mechanical characteristics of the tissue much more accurately than the surgeon himself can do. As the mechanical characteristics of tumour and healthy tissue differ but slightly, the task is to design a system with high sensitivity. Therefore, we have developed a resonant actuator-sensor that allows the differentiation among distinct media that have similar mechanical characteristics to tumour and healthy tissue using a piezoelectric bimorph. The design is based on the detection and evaluation of frequency shift and amplitude variation of the fundamental and higher harmonics using one layer for the resonant excitation of vibration and the other one as the sensing element.}}, author = {{Stroop, Ralf and Uribe, David Oliva and Martinez, Melisa Orta and Brökelmann, Michael and Hemsel, Tobias and Wallaschek, Jörg}}, issn = {{1385-3449}}, journal = {{Journal of Electroceramics}}, keywords = {{Piezo ceramics, Bimorph, Tactile sensor, Tumour tissue}}, number = {{3-4}}, pages = {{237--241}}, publisher = {{Springer US}}, title = {{{Tactile tissue characterisation by piezoelectric systems}}}, doi = {{10.1007/s10832-007-9183-6}}, volume = {{20}}, year = {{2008}}, } @article{9575, abstract = {{Many ultrasonic processes are based on the mechanical contact of oscillating parts. Within ultrasonic machining (drilling, milling, grinding) micro impacts lead to abrasion at the processed workpiece and hopefully do not damage the tool. In ultrasonic motors ideally neither part gets worn. Thus the appropriate design of contact partners as well as their kinematics is a substantial task during the development of such devices. A first step to optimize contact mechanics is to understand their behavior and dependencies on parameter variations, such as vibration amplitude and pre-stress of the impacting parts. For a detailed understanding models validated with convincing experimental data from measurements are absolutely essential. This paper focuses on simple vibro-impact experiments which can be used as benchmark data for future models. The setup of the experiment and first experimental investigations are described in detail.}}, author = {{Twiefel, Jens and Potthast, Christian and Mracek, Maik and Hemsel, Tobias and Sattel, Thomas and Wallaschek, Jörg}}, issn = {{1385-3449}}, journal = {{Journal of Electroceramics}}, keywords = {{Contact measurements, Vibro-impact, Ultrasonic application}}, number = {{3-4}}, pages = {{209--214}}, publisher = {{Springer US}}, title = {{{Fundamental experiments as benchmark problems for modeling ultrasonic micro-impact processes}}}, doi = {{10.1007/s10832-007-9169-4}}, volume = {{20}}, year = {{2008}}, } @inproceedings{9576, abstract = {{In neurosurgery, delineation of tumor boundaries during resection of brain tumors is of substantial relevance. During operation distinction between tumor and healthy tissue rely on the abilities of the surgeon based on visual and tactile differentiation. In this paper a high sensitivity actuator-sensor system using a piezoelectric bimorph is presented. Frequency shift and transfer function of the bimorphpsilas voltages are detected and evaluated. Sensorpsilas sensitivity is evaluated using two frequency controls strategies: A phase-locked loop (PLL) and a self-oscillating circuit. Results of measurements conducted on gel-phantoms are presented and discussed.}}, author = {{Uribe, David Oliva and Stroop, Ralf and Hemsel, Tobias and Wallaschek, Jörg}}, booktitle = {{Frequency Control Symposium, 2008 IEEE International}}, issn = {{1075-6787}}, keywords = {{biomedical measurement, brain, cancer, neurophysiology, phantoms, phase locked loops, piezoelectric actuators, surgery, tactile sensors, transfer functions, tumours, PLL, biomedical tissue differentiation system, brain tumor resection, frequency control, frequency shift, gel-phantom, high sensitivity actuator-sensor system, neurosurgery, phase-locked loop, piezoelectric actuators, piezoelectric bimorph, self-oscillating circuit, sensor sensitivity, tactile differentiation, tactile sensor system, transfer function, tumor boundary, visual differentiation, Biomedical measurements, Circuits, Frequency control, Neoplasms, Neurosurgery, Phase locked loops, Piezoelectric actuators, Surges, Transfer functions, Voltage}}, pages = {{91--94}}, title = {{{Development of a biomedical tissue differentiation system using piezoelectric actuators}}}, doi = {{10.1109/FREQ.2008.4622963}}, year = {{2008}}, } @inbook{9590, author = {{Beutner, Marc}}, booktitle = {{Qualität in Schule und Betrieb. Forschungsergebnisse und gute Praxis}}, editor = {{Bals, T and Hegemann, K and Wilbers, K}}, pages = {{333 -- 344}}, title = {{{Evaluation von Standards und Evaluation für Standards. Zentraler Tagungsband der 15. Hochschultage Berufliche Bildung}}}, year = {{2008}}, } @misc{9640, author = {{Tönnies, Merle}}, booktitle = {{Archiv für das Studium der neueren Sprachen und Literaturen}}, number = {{1}}, pages = {{155--156}}, title = {{{Caselli, D.: Beckett's Dante}}}, volume = {{245}}, year = {{2008}}, } @inbook{9702, author = {{Strauß, Sara}}, booktitle = {{Peter Ustinov als Autor – Eine Einführung}}, editor = {{Breuer, Rolf}}, pages = {{170--173}}, publisher = {{Fink}}, title = {{{The Frontiers of the Sea}}}, year = {{2008}}, } @inbook{9703, author = {{Strauß, Sara}}, booktitle = {{Peter Ustinov als Autor – Eine Einführung}}, editor = {{Breuer, Rolf}}, pages = {{178--181}}, publisher = {{Fink}}, title = {{{A Nose By Any Other Name}}}, year = {{2008}}, } @article{4156, author = {{Hehenkamp, Burkhard and Kaarbøe, Oddvar M.}}, issn = {{0165-1889}}, journal = {{Journal of Economic Dynamics and Control}}, number = {{5}}, pages = {{1357--1380}}, publisher = {{Elsevier BV}}, title = {{{Imitators and optimizers in a changing environment}}}, doi = {{10.1016/j.jedc.2007.06.001}}, volume = {{32}}, year = {{2008}}, } @article{4187, abstract = {{We study phonon-assisted electron tunneling in semiconductor quantum dot molecules. In particular, singletsinglet relaxation in a two-electron-doped structure is considered. The influence of Coulomb interaction is discussed via comparison with a single-electron system. We find that the relaxation rate reaches similar values in the two cases but the Coulomb interaction shifts the maximum rates toward larger separations between the dots. The difference in electron-phonon interaction between deformation potential and piezoelectric coupling is investigated. We show that the phonon-induced tunneling between two-electron singlet states is a fast process, taking place on the time scales of the order of a few tens of picoseconds.}}, author = {{Grodecka, A. and Machnikowski, P. and Förstner, Jens}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, keywords = {{tet_topic_qd}}, number = {{8}}, publisher = {{American Physical Society (APS)}}, title = {{{Phonon-assisted tunneling between singlet states in two-electron quantum dot molecules}}}, doi = {{10.1103/physrevb.78.085302}}, volume = {{78}}, year = {{2008}}, }