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 $C$. }}, author = {{Schindelhauer, Christian and Volbert, Klaus and Ziegler, Martin}}, booktitle = {{Proc. of 15th Annual International Symposium on Algorithms and Computation (ISAAC'04)}}, isbn = {{9783540241317}}, issn = {{0302-9743}}, pages = {{805--821}}, publisher = {{Springer }}, title = {{{Spanners, Weak Spanners, and Power Spanners for Wireless Networks}}}, doi = {{10.1007/978-3-540-30551-4_69}}, volume = {{3341}}, year = {{2004}}, } @article{18281, author = {{Tophinke, Doris}}, journal = {{Infodienst. Kulturpädagogische Nachrichten }}, pages = {{26--27}}, title = {{{Quatschwörterverse und Satzklötze. Sprachförderung im Kindergarten}}}, volume = {{71}}, year = {{2004}}, } @inproceedings{18364, abstract = {{The visualisation of manufacturing-processes assists the user in understanding and analysis. Typically he can move free and unguided in a virtual environment which visualizes the entire process. Thus knowledge and conclusions are to some extend acquired on a random base. This article describes the development of a tool, which enables the user to interactively improve significant production processes in the simulation. He moves in a virtual 3D-environment (walkthrough system) and is able to acquire automatically calculated indications for significant processes. At the same time the simulation considers significant objects in a more detailed way. If the viewer is interested in a significant process, he is automatically guided to the relevant location where he can examine the critical situation by modification of the simulation model.}}, author = {{Mueck, Bengt and Dangelmaier, Wilhelm and Laroque, Christoph and Fischer, Matthias and Kortenjan, Michael}}, booktitle = {{Simulation and Visualisation 2004}}, pages = {{73--83}}, publisher = {{SCS European Publishing House}}, title = {{{Guidance of Users in Interactive 3D-Visualisations of Material Flow Simulations}}}, year = {{2004}}, }