@article{16551, abstract = {{ Spiral patterns have been observed experimentally, numerically, and theoretically in a variety of systems. It is often believed that these spiral wave patterns can occur only in systems of reaction–diffusion equations. We show, both theoretically (using Hopf bifurcation techniques) and numerically (using both direct simulation and continuation of rotating waves) that spiral wave patterns can appear in a single reaction–diffusion equation [ in u(x, t)] on a disk, if one assumes "spiral" boundary conditions (ur = muθ). Spiral boundary conditions are motivated by assuming that a solution is infinitesimally an Archimedian spiral near the boundary. It follows from a bifurcation analysis that for this form of spirals there are no singularities in the spiral pattern (technically there is no spiral tip) and that at bifurcation there is a steep gradient between the "red" and "blue" arms of the spiral. }}, author = {{Dellnitz, Michael and Golubitsky, Martin and Hohmann, Andreas and Stewart, Ian}}, issn = {{0218-1274}}, journal = {{International Journal of Bifurcation and Chaos}}, pages = {{1487--1501}}, title = {{{Spirals in Scalar Reaction–Diffusion Equations}}}, doi = {{10.1142/s0218127495001149}}, year = {{1995}}, } @article{16566, author = {{Breslauer, Dany and Czumaj, Artur and Dubhashi, Devdatt P. and Meyer auf der Heide, Friedhelm}}, issn = {{0020-0190}}, journal = {{Information Processing Letters}}, pages = {{103--110}}, title = {{{Transforming comparison model lower bounds to the parallel-random-access-machine}}}, doi = {{10.1016/s0020-0190(97)00032-x}}, year = {{1995}}, } @inbook{16611, author = {{Golubitsky, Martin and Marsden, Jerrold and Stewart, Ian and Dellnitz, Michael}}, booktitle = {{Normal Forms and Homoclinic Chaos}}, isbn = {{9780821803264}}, title = {{{The constrained Liapunov-Schmidt procedure and periodic orbits}}}, doi = {{10.1090/fic/004/05}}, year = {{1995}}, } @inbook{16704, author = {{Meyer auf der Heide, Friedhelm and Vöcking, Berthold}}, booktitle = {{STACS 95}}, isbn = {{9783540590422}}, issn = {{0302-9743}}, title = {{{A packet routing protocol for arbitrary networks}}}, doi = {{10.1007/3-540-59042-0_81}}, year = {{1995}}, } @inbook{16705, author = {{Czumaj, Artur and Meyer auf der Heide, Friedhelm and Stemann, Volker}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783540603139}}, issn = {{0302-9743}}, title = {{{Shared memory simulations with triple-logarithmic delay}}}, doi = {{10.1007/3-540-60313-1_133}}, year = {{1995}}, } @inproceedings{16706, author = {{Meyer auf der Heide, Friedhelm and Storch, Martin and Wanka, Rolf}}, booktitle = {{Proceedings of the seventh annual ACM symposium on Parallel algorithms and architectures - SPAA '95}}, isbn = {{0897917170}}, title = {{{Optimal trade-offs between size and slowdown for universal parallel networks}}}, doi = {{10.1145/215399.215430}}, year = {{1995}}, } @inproceedings{16707, author = {{Czumaj, Artur and Meyer auf der Heide, Friedhelm and Stemann, Volker}}, booktitle = {{Proceedings Third Israel Symposium on the Theory of Computing and Systems}}, isbn = {{0818669152}}, title = {{{Improved optimal shared memory simulations, and the power of reconfiguration}}}, doi = {{10.1109/istcs.1995.377051}}, year = {{1995}}, } @inbook{16717, author = {{Meyer auf der Heide, Friedhelm and Westermann, Matthias}}, booktitle = {{Graph-Theoretic Concepts in Computer Science}}, isbn = {{9783540606185}}, issn = {{0302-9743}}, title = {{{Hot-potato routing on multi-dimensional tori}}}, doi = {{10.1007/3-540-60618-1_77}}, year = {{1995}}, } @inbook{16874, author = {{Bäumker, Armin and Dittrich, Wolfgang and Meyer auf der Heide, Friedhelm}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783540603139}}, issn = {{0302-9743}}, title = {{{Truly efficient parallel algorithms: c-optimal multisearch for an extension of the BSP model}}}, doi = {{10.1007/3-540-60313-1_131}}, year = {{1995}}, } @article{10610, author = {{Platzner, Marco and Rinner, Bernhard and Weiss, Reinhold}}, journal = {{J.UCS Journal of Universal Computer Science}}, pages = {{811--820}}, publisher = {{Springer}}, title = {{{Exploiting Parallelism in Constraint Satisfaction for Qualitative Simulation}}}, volume = {{12}}, year = {{1995}}, } @inproceedings{11757, abstract = {{Clustering techniques have been integrated at different levels into the training procedure of a continuous-density hidden Markov model (HMM) speech recognizer. These clustering techniques can be used in two ways. First acoustically similar states are tied together. It will help to reduce the number of parameters but also allow to train otherwise rarely seen states together with more robust ones (state-tying). Secondly densities are clustered across states, this reduces the number of densities while at the same time keeping the best performances of our recognizer (density-clustering). We have applied these techniques both to word-based small-vocabulary and phoneme-based large-vocabulary recognition tasks. On the WSJ task, we could achieve a reduction of the word error rate by 7%. On the TI/NIST-connected digit task, the number of parameters was reduced by a factor 2-3 while keeping the same string error rate.}}, author = {{Dugast, Christian and Beyerlein, Peter and Haeb-Umbach, Reinhold}}, booktitle = {{ICASSP, Detroit}}, title = {{{Application of Clustering Techniques to Mixture Density Modelling for Continuous-Speech Recognition}}}, year = {{1995}}, } @article{11764, abstract = {{Today speech recognition of a small vocabulary can be realized so cost-effectively that the technology can penetrate into consumer electronics. But, as first applications that failed on the market show, it is by no means obvious how to incorporate voice control in a user interface. This paper addresses the issue of how to design a voice control so that the user perceives it as a benefit. User interface guidelines that are adapted or specific to voice control are presented. Then the process of designing a voice control in the user-centred approach is described. By means of two examples, the car stereo and telephone answering machine, it is shown how this is turned into practice.}}, author = {{Gamm, Stephan and Haeb-Umbach, Reinhold}}, journal = {{Philips Journal of Research}}, title = {{{User interface design of voice controlled consumer electronics}}}, year = {{1995}}, } @inproceedings{11765, author = {{Gamm, Stephan and Haeb-Umbach, Reinhold}}, booktitle = {{Eurospeech, Madrid}}, title = {{{Human Factors of a Voice-Controlled Car Stereo}}}, year = {{1995}}, } @inproceedings{11768, author = {{Gamm, Stephan and Haeb-Umbach, Reinhold and Langmann, Det}}, booktitle = {{International Symposium on Human Factors in Telecommunications, Melbourne}}, title = {{{The Usability Engineering of a Voice-Controlled Answering Machine}}}, year = {{1995}}, } @article{11786, abstract = {{Recognition accuracy has been the primary objective of most speech recognition research, and impressive results have been obtained, e.g. less than 0.3% word error rate on a speaker-independent digit recognition task. When it comes to real-world applications, robustness and real-time response might be more important issues. For the first requirement we review some of the work on robustness and discuss one specific technique, spectral normalization, in more detail. The requirement of real-time response has to be considered in the light of the limited hardware resources in voice control applications, which are due to the tight cost constraints. In this paper we discuss in detail one specific means to reduce the processing and memory demands: a clustering technique applied at various levels within the acoustic modelling.}}, author = {{Haeb-Umbach, Reinhold and Beyerlein, Peter and Geller, Dieter}}, journal = {{Philips Journal of Research}}, title = {{{Speech recognition algorithms for voice control interfaces}}}, year = {{1995}}, } @inproceedings{11787, abstract = {{We address the problem of automatically finding an acoustic representation (i.e. a transcription) of unknown words as a sequence of subword units, given a few sample utterances of the unknown words, and an inventory of speaker-independent subword units. The problem arises if a user wants to add his own vocabulary to a speaker-independent recognition system simply by speaking the words a few times. Two methods are investigated which are both based on a maximum-likelihood formulation of the problem. The experimental results show that both automatic transcription methods provide a good estimate of the acoustic models of unknown words. The recognition error rates obtained with such models in a speaker-independent recognition task are clearly better than those resulting from separate whole-word models. They are comparable with the performance of transcriptions drawn from a dictionary.}}, author = {{Haeb-Umbach, Reinhold and Beyerlein, P. and Thelen, E.}}, booktitle = {{ICASSP, Detroit}}, title = {{{Automatic Transcription of Unknown Words in a Speech Recognition System}}}, year = {{1995}}, } @article{11905, abstract = {{This paper gives an overview of the Philips Research system for continuous-speech recognition. The recognition architecture is based on an integrated statistical approach. The system has been successfully applied to various tasks in American English and German, ranging from small vocabulary tasks to very large vocabulary tasks and from recognition only to speech understanding. Here, we concentrate on phoneme-based continuous-speech recognition for large vocabulary recognition as used for dictation, which covers a significant part of our research work on speech recognition. We describe this task and report on experimental results. In order to allow a comparison with the performance of other systems, a section with an evaluation on the standard North American Business news (NAB2) task (dictation of American English newspaper text) is supplied.}}, author = {{Steinbiss, Volker and Ney, Hermann J. and Aubert, Xavier L. and Besling, Stefan and Dugast, Christian and Essen, Ute and Geller, Dieter and Haeb-Umbach, Reinhold and Kneser, Reinhard and Meier, Hans Günter and Oerder, Martin and Tran, Bach Hiep}}, journal = {{Philips Journal of Research}}, title = {{{The Philips Research system for continuous-speech dictation}}}, year = {{1995}}, } @article{11948, abstract = {{This paper gives an overview of the Philips research system for phoneme-based, large-vocabulary, continuousspeech recognition. The system has been successfully applied to various tasks in the German and (American) English languages, ranging from small vocabulary tasks to very large vocabulary tasks. Here, we concentrate on continuousspeech recognition for dictation in real applications, the dictation of legal reports and radiology reports in German. We describe this task and report on experimental results. We also describe a commercial PC-based dictation system which includes a PC implementation of our scientific recognition prototype. In order to allow for a comparison with the performance of other systems, a section with an evaluation on the standard Wall Street Journal task (dictation of American English newspaper text) is supplied. The recognition architecture is based on an integrated statistical approach. We describe the characteristic features of the system as opposed to other systems: 1. the Viterbi criterion is consistently applied both in training and testing; 2. continuous mixture densities are used without tying or smoothing; 3. time-synchronous beam search in connection with a phoneme look-ahead is applied to a tree-organized lexicon.}}, author = {{Steinbiss, Volker and Ney, Hermann J. and Essen, Ute and Tran, Bach Hiep and Aubert, Xavier L. and Dugast, Christian and Kneser, Reinhard and Meier, Hans Günter and Oerder, Martin and Haeb-Umbach, Reinhold and Geller, Dieter and Hoellerbauer, W. and Bartosik, H.}}, journal = {{Speech Communication}}, title = {{{Continuous speech dictation - From theory to practice}}}, year = {{1995}}, } @techreport{13026, author = {{Hellebrand, Sybille and Wunderlich, Hans-Joachim}}, title = {{{Synthesis Procedures for Self-Testable Controllers}}}, year = {{1995}}, } @techreport{13027, author = {{Hellebrand, Sybille and Wunderlich, Hans-Joachim and Goncalves, F. and Paulo Teixeira, Joao}}, title = {{{Evaluation of Self-Testable Controller Architectures Based on Realistic Fault Analysis}}}, year = {{1995}}, }