While it is known that any $c$-spanner is also both a weak $C_1$-spanner and a $C_2$-power spanner (for appropriate $C_1,C_2$ depending only on $c$ but not on the graph under consideration), we show that the converse fails: There exists a family of $c_1$-power spanners that are no weak $C$-spanners and also a family of weak $c_2$-spanners that are no $C$-spanners for any fixed $C$ (and thus no uniform spanners, either). However the deepest result of the present work reveals that, surprisingly, any weak spanner is also a uniform power spanner. We further generalize the latter notion by considering $(c,delta)$-power spanners where the sum of the $delta$-th powers of the lengths has to be bounded; so $(cdot,2)$-power spanners coincide with the usual power spanners and $(cdot,1)$-power spanners are classical spanners. Interestingly, these $(cdot,delta)$-power spanners form a strict hierarchy where the above results still hold for any $deltageq2$; some even hold for $delta>1$ while counterexamples reveal others to fail for $delta<2$. In fact we show that in general every self-similar curve of fractal dimension $d>delta$ is no $(C,delta)$-power spanner for any fixed $C$. AU - Schindelhauer, Christian AU - Volbert, Klaus AU - Ziegler, Martin ID - 18279 SN - 0302-9743 T2 - Proc. of 15th Annual International Symposium on Algorithms and Computation (ISAAC'04) TI - Spanners, Weak Spanners, and Power Spanners for Wireless Networks VL - 3341 ER - TY - CONF AU - Cherchago, Alexey AU - Heckel, Reiko ID - 7923 T2 - Proceedings of the conference on Graph Transformation (ICGT 2004), Rome (Italy) TI - Specification Matching of Web Services Using Conditional Graph Transformation Rules VL - 3256 / 2004 ER - TY - JOUR AU - Krimphove, Dieter ID - 1958 IS - Jg. 35, Heft 1 JF - Rechtstheorie TI - Spieltheoretische Aspekte des Rechts – Ein Beitrag zur Analyse und Gestaltung von Recht mit Hilfe objektiver quanitvizierbaren Methodik – ER - TY - GEN AU - Peckhaus, Volker ID - 18799 T2 - Mathematical Reviews [MR 2004d:01024; online: MathSciNet 1 971 369] TI - Stelzner, Werner, “Compatibility and Relevance: Bolzano and Orlov”, Logic and Logical Philosophy Nr. 10 (2002), 137-171 ER - TY - JOUR AU - Weiß, M AU - Barthel, T AU - Baumeister, Jochen ID - 20482 JF - ForschungsForum TI - Stressmodelle und Analyse der Hirntätigkeit VL - 7 ER - TY - CONF AU - Baresi, Luciano AU - Heckel, Reiko AU - Thöne, Sebastian AU - Varró, Dániel ID - 7918 T2 - Proceedings of the conference on Software Architecture (WICSA 2004), Oslo (Norway) TI - Style-Based Refinement of Dynamic Software Architectures ER - TY - CONF AU - Sohler, Christian AU - Czumaj, Artur ID - 18786 IS - 1 T2 - Automata, Languages and Programming (ICALP) TI - Sublinear-Time Approximation for Clustering via Random Sampling ER - TY - CONF AB - We demonstrate temporal and spatial pulse compression and modulational instabilities in the nonlinear defocusing regime near the band edge of bulk GaAs. Experiment and theory show that spatiotemporal coupling is responsible for these surprising phenomena. AU - Nielsen, Nils. C. AU - Siederdissen, Tilmann H. zu AU - Kuhl, Jürgen AU - Schaarschmidt, Martin AU - Förstner, Jens AU - Knorr, Andreas AU - Koch, Stephan W. AU - Giessen, Harald ID - 4279 KW - tet_topic_polariton SN - 3-54024-110-8 T2 - International Conference on Ultrafast Phenomena 2004 TI - Subpicosecond spatiotemporal pulse compression in a nonlinear defocusing material ER - TY - GEN AU - Peckhaus, Volker ID - 18487 T2 - Zentralblatt für Mathematik und ihre Grenzgebiete [Zbl. 1030.01021] TI - Sundholm, Göran, “Frege, August Bebel and the Return of Alsace-Lorraine: The Dating of the Distinction between Sinn and Bedeutung”, History and Philosophy of Logic 22 (2001), 57–73 ER - TY - CONF AU - Ateniese, Giuseppe AU - Riley, Chris AU - Scheideler, Christian ID - 2123 T2 - IWIA TI - Survivable Monitoring in Dynamic Networks ER - TY - JOUR AU - Knipping, Jörg AU - Wiggers, Hartmut AU - Rellinghaus, Bernd AU - Roth, Paul AU - Konjhodzic, Denan AU - Meier, Cedrik ID - 7679 IS - 8 JF - Journal of Nanoscience and Nanotechnology SN - 1533-4880 TI - Synthesis of High Purity Silicon Nanoparticles in a Low Pressure Microwave Reactor VL - 4 ER - TY - CONF AB - In turbomachinery, friction contacts are widely used to reduce dynamic stresses in turbine blades in order to avoid expensive damages. As a result of energy dissipation in the friction contacts the blade vibration amplitudes are reduced. In case of so-called friction dampers, which are pressed on the platforms of the blades by centrifugal forces, the damping effect can be optimized by varying the damper mass. This optimization can be done by means of a simulation model applying the so-called component mode synthesis and the Harmonic Balance Method to reduce computation time. It is based on the modal description of each substructure. In a real turbine or compressor blading great differences in the magnitude of the individual blade amplitudes occur caused by unavoidable mistuning of all system parameters like contact parameters and natural frequencies of the blades. It may happen that most of the blades experience only small stresses whereas a few blades experience critical stresses. Therefore, it is necessary to consider mistuning for all system parameters to simulate the forced response of bladed disk assemblies with friction contacts. For a mistuned bladed disk the complete system has to be modeled to calculate the dynamic response. In practice, usually the standard deviations instead of the distributions of the system parameters are known. Therefore, Monte-Carlo simulations are necessary to calculate the forced response of the blades for given mean values and standard deviations of the system parameters. To reduce the computational time, an approximate method has been developed and extended for small and moderate standard deviations of the system parameters to calculate the distribution and the envelopes of the frequency response functions for statistically varying system parameters, in the following called statistical mistuning. The approximate method is based on a sensitivity analysis and the assumption of a Weibull distribution of the vibration amplitudes of the blades. Both, the approximate method and the assumption of a Weibull distribution of the vibration amplitudes are validated by Monte-Carlo simulations. By these investigations the influence of different arrangements of the system parameters for given mean values and standard deviations of the vibration amplitudes of the blades can be determined, too. For the present investigations only a small influence of the arrangement of blades with respect to their natural frequencies has been observed. On the other hand, an intentional mistuning of the damper masses and the natural frequencies of the blades in a systematic way, in the following called systematic mistuning, can be investigated to reduce the amplitudes of the system. The simulation results of a systematic mistuning has been validated by a test rig with a rotating bladed disk assembly with friction dampers. The investigations show a good agreement between the simulations and the measurements but only a slight decrease of the maximum amplitudes in case of a systematic mistuning. Copyright {\copyright} 2004 by ASME AU - Götting, Florian AU - Sextro, Walter AU - Panning, Lars AU - Popp, Karl ID - 8952 IS - GT2004-53310 KW - Friction KW - Disks T2 - Proceedings of ASME TURBO Expo, Power for Land, Sea, and Air TI - Systematic mistuning of bladed disk assemblies with friction contacts VL - 6 ER - TY - CONF AU - Küster, Jochen ID - 8389 T2 - Proceedings 3rd UML Workshop in Software Model Engineering (WiSME 2004), Lisbon (Portugal) TI - Systematic Validation of Model Transformations ER -