@inproceedings{9754,
  abstract     = {{A model based design approach for improved piezoelectric inertia motors is presented. Three velocityoptimized movement patterns for the driving body have been derived. The influence of the motor parameters and the process of designing an application specific motor with maximum velocity are shown. A simple dynamic model of the piezoelectric actuator is used to calculate the voltage signal for achieving the desired movement pattern. Observed distortions of the optimum pattern, their influence on the motion of the driven body and different methods to reduce them are discussed.}},
  author       = {{Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}},
  booktitle    = {{ACTUATOR 2010 Conference Proceedings}},
  issn         = {{0924-4247}},
  pages        = {{657--661}},
  title        = {{{Improving the Performance of Piezoelectric Inertia Motors}}},
  year         = {{2010}},
}

@inproceedings{9755,
  author       = {{Kraft , Verena and Bauch, C. and Nückel, M. and Hemsel, Tobias}},
  booktitle    = {{19. Gemeinschaftstagung LICHT 2010}},
  title        = {{{Konzeption und Aufbau eines Langzeitforschungsstandes zur lichttechnischen Charakterisierung von organischen Leuchtdioden (OLEDs)}}},
  year         = {{2010}},
}

@article{9756,
  abstract     = {{Dieser Beitrag fasst die bekannten analytischen Berechnungsmethoden für piezoelektrische Ultraschallverbundschwinger zusammen und gibt anhand typischer Beispiele Anleitungen zur Lösung theoretischer und technischer Fragen bei deren Entwicklung. Zunächst werden die passiven, in der Regel metallischen Komponenten von Verbundschwingern als Stab- oder Plattensysteme mit homogen verteilten Feder-, Masse und Dämpfungseigenschaften beschrieben. Hier breitet sich die Schwingungsenergie in Form stehender und fortschreitender Wellen zum akustischen Verbraucher hin aus. Es folgt eine gleichwertige und schaltungstreue Darstellung durch elektrische oder mechanische Vierpole, die für den Entwicklungsingenieur leichter zu handhaben sind und in Netzwerken direkt mit Masons Ersatzschaltung des piezoelektrischen Wandlers gekoppelt werden können. Danach werden die wichtigsten, messtechnisch zugänglichen Parameter anhand eines in Resonanznähe zulässigen Ersatzmodells mit konzentrierten elektrischen bzw. mechanischen Komponenten definiert. Als Schwerpunkt wird anschließend deren analytische Berechnung und messtechnische Verifizierung an typischen Beispielen demonstriert. Es folgen wichtige technische Informationen über Frequenzkorrekturen, Schallgeschwindigkeitsdispersion, Leistungs- und Belastbarkeitsgrenzen der Komponenten und andere wertvolle praktische Hinweise.}},
  author       = {{Lierke, Ernst-Günter and Littmann, Walter and Hemsel, Tobias}},
  issn         = {{1948-5719}},
  journal      = {{Veröffentlichung der Universität Paderborn}},
  title        = {{{Zur Theorie der piezoelektrischen Ultraschallverbundschwinger mit praktischen Schlussfolgerungen für den Entwicklungsingenieur}}},
  year         = {{2010}},
}

@article{9757,
  author       = {{Lucinskis, Raimundas and Mazeika, Dalius and Hemsel, Tobias and Bansevicius, Ramutis}},
  issn         = {{1948-5719}},
  journal      = {{MECHANIKA}},
  title        = {{{The experimental research of piezoelectric actuator with two vectors of polarization direction}}},
  year         = {{2010}},
}

@article{9758,
  abstract     = {{As a lead-free piezoelectric ceramics, (K,Na)NbO$_{3}$ is a promising material because of its good piezoelectric properties. In this study, (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics were synthesized from a KNbO$_{3}$ and NaNbO$_{3}$ mixture powder prepared by the hydrothermal reaction. The hydrothermal reaction enables the production of high quality powder for the ceramics fabrication process. To obtain (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics, these two powders KNbO$_{3}$ and NaNbO$_{3}$ were mixed and then sintered together. X-Ray diffraction analysis revealed that the solid solution ceramics (K$_{1-x}$Na$_{x}$)NbO$_{3}$ was produced by the sintering process. The K/Na ratio in (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics was optimized for the best piezoelectric properties. The optimized forms was (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$, which showed the following piezoelectric properties; k$_{33}$=0.56, d$_{33}$=114pC/N. In addition, the ferroelectric properties, P$_{r}$=7.72mC/cm$^{2}$, E$_{c}$=857V/mm, and the Curie temperature T$_{c}$=420$_{o}$C were also measured.}},
  author       = {{Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}},
  issn         = {{1948-5719}},
  journal      = {{Journal of Korean Physical Society}},
  keywords     = {{Lead-free piezoelectric material, KNN, Hydrothermal method}},
  number       = {{4}},
  pages        = {{924--928}},
  title        = {{{Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics}}},
  doi          = {{10.3938/jkps.57.924}},
  volume       = {{57}},
  year         = {{2010}},
}

@article{9759,
  abstract     = {{Among various lead-free piezoelectric materials, (K,Na)NbO$_{3}$ is a very promising candidate. In this study, (K,Na)NbO$_{3}$ ceramics were sintered from mixed (K,Na)NbO$_{3}$ and NaNbO$_{3}$ powders prepared by hydrothermal reaction. These two powders were mixed with distilled water in a KNbO$_{3}$/NaNbO$_{3}$ molar ratio of 1. After sintering the mixed powder, the solid solution of (Na,K)NbO$_{3}$ ceramics was obtained. The electrical properties such as the electromechanical coupling factors k$_{p}$ and k$_{33}$, the mechanical quality factor, Q$_{m}$, and the piezoelectric constant d$_{33}$ of the sintered (K,Na)NbO$_{3}$ ceramics were 0.32, 0.48, 71 (radial mode), 118 ((33)mode), and 107 pC/N, respectively.}},
  author       = {{Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}},
  issn         = {{1948-5719}},
  journal      = {{Materials Letters}},
  keywords     = {{Lead-free piezoelectric material, (K, Na)NbO$_{3}$ ceramics, Sintering solid solution, Piezoelectric properties}},
  number       = {{2}},
  pages        = {{125--128}},
  title        = {{{(K,Na)NbO3 lead-free piezoelectric ceramics synthesized from hydrothermal powders}}},
  doi          = {{10.1016/j.matlet.2009.10.012}},
  volume       = {{64}},
  year         = {{2010}},
}

@inproceedings{9760,
  abstract     = {{Self-optimizing systems are able to adapt their behavior autonomously according to their current self-determined objectives. Unforeseen influences could lead to dependability-critical behavior of the system. Methods are required which secure self-optimizing systems during operation. These methods to increase the dependability of the system should already be taken into consideration in the design process. This paper presents a guideline for the dependability-oriented design of self-optimizing systems, which integrates established classical methods like failure mode and effects analysis as well as methods based on self-optimization. On the one hand self-optimization is used to increase the dependability of the system by integrating objectives like safety, availability, and reliability to the objectives of the system. On the other hand methods are required to ensure the self-optimization itself. As basis for this guideline serves the principle solution of the system. The six phases of the guideline extend the design process and lead to an enhanced principle solution. Additionally, the guideline illustrates phases to implement and validate the self-optimizing system. The proposed guideline is applied to an innovative rail-bound vehicle, called RailCab, which is equipped with self-optimizing function modules.}},
  author       = {{Sondermann-Wölke, Christoph and Hemsel, Tobias and Sextro, Walter and Gausemeier, Jürgen and Pook, Sebastian}},
  booktitle    = {{Industrial Informatics (INDIN), 2010 8th IEEE International Conference on}},
  keywords     = {{RailCab, dependability-critical behavior, dependability-oriented design, failure mode, rail-bound vehicle, secure self-optimizing systems, self-optimizing function modules, optimisation, railways, self-adjusting systems}},
  pages        = {{739 --744}},
  title        = {{{Guideline for the dependability-oriented design of self-optimizing systems}}},
  doi          = {{10.1109/INDIN.2010.5549490}},
  year         = {{2010}},
}

@article{9761,
  abstract     = {{New mechatronic systems, called self-optimizing systems, are able to adapt their behavior according to environmental, user and system specific influences. Self-optimizing systems are complex and due to their non-deterministic behavior comprise hidden risks, which cannot be foreseen in the design phase of the system. Therefore, modifications of the ISO 17359 condition monitoring policy for being able to cope with this new kind of systems are presented. Besides avoiding critical situations evoked by self-optimization, the proposed concept uses self-optimization to increase the dependability of the system. This concept is applied to the active guidance module of an innovative rail-bound vehicle. First test drives provide information for the enhancement of the implementation of realtime switching to appropriate control strategies. The different control strategies are investigated in detail. It is illustrated that influences on the system like different track sections or the desired velocity of the RailCab effect the system and can lead to a higher amount of flange contacts, which indicate higher wear and thus a reduction of the availability of the system. Therefore, these influences should be minded within the condition monitoring policy. Consequently, this article presents the condition monitoring policy for self-optimizing function modules and its application to the active railway guidance module.}},
  author       = {{Sondermann-Wölke, Christoph and Sextro, Walter}},
  journal      = {{International Journal On Advances in Intelligent Systems}},
  keywords     = {{dependability, condition monitoring, selfoptimization, active railway guidance module}},
  number       = {{1 - 3}},
  pages        = {{65 -- 74}},
  title        = {{{Integration of Condition Monitoring in Self-optimizing Function Modules Applied to the Active Railway Guidance Module}}},
  volume       = {{3}},
  year         = {{2010}},
}

@inproceedings{9762,
  abstract     = {{Die erweiterten Möglichkeiten der Informationsverarbeitung mechatronischer Systeme erlauben es, mechatronische Systeme selbstoptimierend zu gestalten. Dabei bezieht sich die Selbstoptimierung auf die Fähigkeit des Systems, sich an die aktuelle Umfeldsituation anzupassen; wobei das System im Allgemeinen mehrere relevante Ziele verfolgt. Wurde eine Umfeldveränderung bemerkt, so müssen diese Ziele an die neue Situation angepasst und das resultierende Verhalten ausgewählt werden. In diesem Beitrag wird das selbstoptimierende Spurführungsmodul näher untersucht. Das Spurführungsmodul ist Bestandteil eines innovativen schienengebundenen Verkehrssystems, genannt RailCab, und dient zur Lenkung des einzelnen Fahrzeugs. Ziele des Spurführungsmoduls bestehen darin, die Verlässlichkeit des Spurführungsmoduls zu erhöhen sowie möglichst wenig Energie zu verbrauchen. Um kritische Systemzustände zu erkennen bzw. frühzeitig zu verhindern wird eine Vorgehensweise zur Einrichtung einer Zustandsüberwachung für selbstoptimierende Systeme beschrieben. Diese wird auf dem realen Versuchsträger im Maßstab 1:2,5 implementiert. Die Auswertung von Versuchsfahrten zeigt, dass gerade beim Auftreten eines Fehlers das Umschalten vom Ziel ''Energieverbrauch minimieren`` auf das Ziel ''Verlässlichkeit maximieren`` sinnvoll ist.}},
  author       = {{Sondermann-Wölke, Christoph and Sextro, Walter and Geisler, Jens and Trächtler, Ansgar}},
  booktitle    = {{Entwurf mechatronischer Systeme}},
  editor       = {{Gausemeier, Jürgen and Rammig, Frans Josef and Trächtler, Ansgar}},
  keywords     = {{Selbstoptimierung, Spurführungsmodul}},
  pages        = {{411 -- 420}},
  title        = {{{Experimentelle Untersuchung der Selbstoptimierung innerhalb des RailCab-Spurführungsmoduls}}},
  volume       = {{272}},
  year         = {{2010}},
}

@inproceedings{9763,
  abstract     = {{Recent advances in information processing enable new kinds of technical systems, called self-optimizing systems. These systems are able to adapt their objectives and their behavior according to the current situation and influences autonomously. This behavior adaptation is non-deterministic and hence self-optimization is a risk to the system, e.g. if the result of the self-optimization process does not match the suddenly changed situation. In contrary, self-optimization could be used to increase the dependability by pursuing objectives like reliability and availability. In our preceding publications we introduced the so called multi-level dependability concept to cope with this new kind of systems (cf. [6]). This concept comprises the monitoring of the system behavior, the classification of the current situation, and the selection of the appropriate measure, if reliability limits are exceeded. In this paper we present for the first time experimental results. The dependability concept is implemented in the self-optimizing active guidance system of a railway vehicle. The test drives illustrate clearly that the proposed concept is able to cope with, e.g., sensor failures, and is able to increase the reliability and availability of the active guidance module.}},
  author       = {{Sondermann-Wölke, Christoph and Geisler, Jens and Sextro, Walter}},
  booktitle    = {{Reliability and Maintainability Symposium (RAMS), 2010 Proceedings - Annual}},
  issn         = {{0149-144X}},
  keywords     = {{availability, dependability concept, multilevel dependability concept, railway vehicle, reliability, self optimizing active guidance system, self optimizing railway guidance system, situation classification, system behavior monitoring, optimal control, railways, reliability theory, self-adjusting systems}},
  pages        = {{1 --6}},
  title        = {{{Increasing the reliability of a self-optimizing railway guidance system}}},
  doi          = {{10.1109/RAMS.2010.5448080}},
  year         = {{2010}},
}

@article{9764,
  author       = {{Tomberger, Christoph and Dietmaier, Peter and Martin, Rosenberger and Sextro, Walter and Six, Klaus}},
  issn         = {{0043-1648}},
  journal      = {{ZEVrail}},
  pages        = {{127--135}},
  title        = {{{Einfluss von Oberflächenrauheit, fluiden Zwischenschichten und Kontakttemperaturen auf den Kraftschluss zwischen Rad und Schiene}}},
  volume       = {{134}},
  year         = {{2010}},
}

@article{4129,
  abstract     = {{We study a single quantum dot molecule doped with one electron in the presence of electron-phonon coupling. Both diagonal and off-diagonal interactions representing real and virtual processes with acoustic phonons via deformation potential and piezoelectric coupling are taken into account. We employ a non-perturbative quantum kinetic theory and show that the phonon-mediated relaxation is dominated by an electron tunneling on a picosecond time scale.A dependence of the relaxation on the temperature and the strength of the tunneling coupling is analyzed.}},
  author       = {{Grodecka-Grad, Anna and Förstner, Jens}},
  issn         = {{1742-6596}},
  journal      = {{Journal of Physics: Conference Series}},
  keywords     = {{tet_topic_qd}},
  publisher    = {{IOP Publishing}},
  title        = {{{Phonon-mediated relaxation in doped quantum dot molecules}}},
  doi          = {{10.1088/1742-6596/245/1/012035}},
  volume       = {{245}},
  year         = {{2010}},
}

@article{4144,
  abstract     = {{Non-polar relaxed cubic GaN was grown by molecular beam epitaxy (MBE) on nano-patterned 3C-SiC/Si 
(0 0 1)substrates with negligible hexagonal content and less defect density than in planar cubic GaN layers.Nano-patterning of 3C-SiC/Si(001) is achieved by self-ordered colloidal masks for the first time. The method presented here offers the possibility to create nano-patterned cubic GaN without the need for a GaN etching process andt hus isa potential alternative to the conventional top–down fabrication techniques.}},
  author       = {{Kemper, R.M. and Weinl, M. and Mietze, C. and Häberlen, M. and Schupp, T. and Tschumak, E. and Lindner, Jörg and Lischka, K. and As, Donald }},
  issn         = {{0022-0248}},
  journal      = {{Journal of Crystal Growth}},
  number       = {{1}},
  pages        = {{84--87}},
  publisher    = {{Elsevier BV}},
  title        = {{{Growth of cubic GaN on nano-patterned 3C-SiC/Si (001) substrates}}},
  doi          = {{10.1016/j.jcrysgro.2010.12.042}},
  volume       = {{323}},
  year         = {{2010}},
}

@article{4153,
  abstract     = {{Nanosphere lithography (NSL) masks consisting of mono- or double-layers of polystyrene (PS) nano-beads are fabricated on silicon exploiting the self-organization of PS particles during the controlled drying of a colloidal suspension on a surface. The shape changes and shrinkage of PS sphere masks upon treatment in an air plasma are studied as a function of initial sphere size, plasma power and treatment time. The influence of several experimental parameters, including the plasma induced temperature rise, are analysed using scanning and transmission electron microscopy. It is demonstrated that a variety of new intriguing nanopatterns can be generated on silicon surfaces by the combination of NSL and plasma techniques, largely broadening the variety of patterns available so far by NSL.}},
  author       = {{Gogel, D. and Weinl, M. and Lindner, Jörg and Stritzker, B.}},
  journal      = {{JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS}},
  number       = {{3}},
  pages        = {{740--744}},
  title        = {{{Plasma modification of nanosphere lithography masks made of polystyrene beads}}},
  volume       = {{12}},
  year         = {{2010}},
}

@article{4154,
  author       = {{Hehenkamp, Burkhard and Possajennikov, Alex and Guse, Tobias}},
  issn         = {{0167-2681}},
  journal      = {{Journal of Economic Behavior & Organization}},
  number       = {{2}},
  pages        = {{254--258}},
  publisher    = {{Elsevier BV}},
  title        = {{{On the equivalence of Nash and evolutionary equilibrium in finite populations}}},
  doi          = {{10.1016/j.jebo.2009.08.011}},
  volume       = {{73}},
  year         = {{2010}},
}

@article{4155,
  author       = {{Angerhausen, Julia and Bayer, Christian and Hehenkamp, Burkhard}},
  journal      = {{Journal of Institutional and Theoretical Economics (JITE)}},
  number       = {{3}},
  pages        = {{439--461}},
  publisher    = {{Mohr Siebeck}},
  title        = {{{Strategic Unemployment}}},
  volume       = {{166}},
  year         = {{2010}},
}

@article{4174,
  abstract     = {{A quantum dot molecule doped with a single electron in the presence of diagonal and off-diagonal carrierphonon
couplings is studied by means of a nonperturbative quantum kinetic theory. The interaction with acoustic phonons by deformation potential and piezoelectric coupling is taken into account. We show that the phonon-mediated relaxation is fast on a picosecond time scale and is dominated by the usually neglected off-diagonal coupling to the lattice degrees of freedom leading to phonon-assisted electron tunneling. We show that in the parameter regime of current electrical and optical experiments, the microscopic non-Markovian theory has to be employed.}},
  author       = {{Grodecka-Grad, A. and Förstner, Jens}},
  issn         = {{1098-0121}},
  journal      = {{Physical Review B}},
  keywords     = {{tet_topic_qd}},
  number       = {{11}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Theory of phonon-mediated relaxation in doped quantum dot molecules}}},
  doi          = {{10.1103/physrevb.81.115305}},
  volume       = {{81}},
  year         = {{2010}},
}

@article{4194,
  abstract     = {{A heterojunction field-effect transistor (HFET) was fabricated of nonpolar cubic AlGaN/GaN grown on Ar+ implanted 3C–SiC (001) by molecular beam epitaxy. The device shows a clear field effect at positive bias voltages with V_th=0.6 V. The HFET output characteristics were calculated using ATLAS simulation program. The electron channel at the cubic AlGaN/GaN interface was detected by room temperature capacitance-voltage measurements.}},
  author       = {{Tschumak, E. and Granzner, R. and Lindner, Jörg and Schwierz, F. and Lischka, K. and Nagasawa, H. and Abe, M. and As, Donald}},
  issn         = {{0003-6951}},
  journal      = {{Applied Physics Letters}},
  number       = {{25}},
  publisher    = {{AIP Publishing}},
  title        = {{{Nonpolar cubic AlGaN/GaN heterojunction field-effect transistor on Ar+ implanted 3C–SiC (001)}}},
  doi          = {{10.1063/1.3455066}},
  volume       = {{96}},
  year         = {{2010}},
}

@article{4200,
  abstract     = {{We studied the Fulde-Ferrell-Larkin-Ovchinnikov-type state established due to the proximity effect in superconducting
Nb/Cu_41Ni_59 bilayers. Using a special wedge-type deposition technique, series of 20–35
samples could be fabricated by magnetron sputtering during one run. The layer thickness of only a few
nanometers, the composition of the alloy, and the quality of interfaces were controlled by Rutherford backscattering
spectrometry, high-resolution transmission electron microscopy, and Auger spectroscopy. The magnetic
properties of the ferromagnetic alloy layer were characterized with superconducting quantum interference
device magnetometry. These studies yield precise information about the thickness and demonstrate the homogeneity
of the alloy composition and magnetic properties along the sample series. The dependencies of the
critical temperature on the Nb and Cu41Ni59 layer thickness, T_c(d_S) and T_c(d_F), were investigated for constant
thickness d_F of the magnetic alloy layer and d_S of the superconducting layer, respectively. All types of
nonmonotonic behaviors of T_c versus d_F predicted by the theory could be realized experimentally, from
reentrant superconducting behavior with a broad extinction region to a slight suppression of superconductivity
with a shallow minimum. Even a double extinction of superconductivity was observed, giving evidence for the
multiple reentrant behavior predicted by theory. All critical temperature curves were fitted with suitable sets of
parameters. Then, T_c(d_F) diagrams of a hypothetical ferromagnet/superconductor/ferromagnet spin-switch core
structure were calculated using these parameters. Finally, superconducting spin-switch fabrication issues are
discussed in detail in view of the achieved results.}},
  author       = {{Zdravkov, V. I. and Kehrle, J. and Obermeier, G. and Gsell, S. and Schreck, M. and Müller, C. and Krug von Nidda, H.-A. and Lindner, Jörg and Moosburger-Will, J. and Nold, E. and Morari, R. and Ryazanov, V. V. and Sidorenko, A. S. and Horn, S. and Tidecks, R. and Tagirov, L. R.}},
  issn         = {{1098-0121}},
  journal      = {{Physical Review B}},
  number       = {{5}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Reentrant superconductivity in superconductor/ferromagnetic-alloy bilayers}}},
  doi          = {{10.1103/physrevb.82.054517}},
  volume       = {{82}},
  year         = {{2010}},
}

@article{4202,
  abstract     = {{Unintentional doping in nonpolar a-plane 
112¯0 gallium nitride 
GaN grown on r-plane 
11¯02
sapphire using a three-dimensional 
3D–two-dimensional 
2D growth method has been
characterized. For both 2D only and 3D–2D growth, the presence of an unintentionally doped region
adjacent to the GaN/sapphire interface is observed by scanning capacitance microscopy 
SCM. The
average width of this unintentionally doped layer is found to increase with increasing 3D growth
time. By using an intentionally doped GaN:Si staircase structure for calibration, it is shown that the
unintentionally doped region has an average carrier concentration of 
2.5
0.31018 cm−3. SCM
also reveals the presence of unintentionally doped features extending at 60° from the GaN/sapphire
interface. The observation of decreasing carrier concentration with distance from the GaN/sapphire
interface along these features may suggest that the unintentional doping arises from oxygen
diffusion from the sapphire substrate. Low temperature cathodoluminescence spectra reveal
emission peaks at 3.41 and 3.30 eV, which are believed to originate from basal plane stacking faults

BSFs and prismatic stacking faults 
PSFs, respectively. It is shown that the inclined features
extending from the GaN/sapphire interface exhibit both enhanced BSF and PSF emission. We
suggest that enhanced unintentional doping occurs in regions around PSFs. Where BSFs intersect
this doped material their emission is also enhanced due to reduced nonradiative recombination.
Transmission electron microscopy confirms the presence of PSFs extending through the film at 60°
from the GaN/sapphire interface.}},
  author       = {{Zhu, Tongtong and Johnston, Carol F. and Häberlen, Maik and Kappers, Menno J. and Oliver, Rachel A.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  number       = {{2}},
  publisher    = {{AIP Publishing}},
  title        = {{{Characterization of unintentional doping in nonpolar GaN}}},
  doi          = {{10.1063/1.3284944}},
  volume       = {{107}},
  year         = {{2010}},
}