Publications

Patents

Papers

Books

• Privacy Protection in Video Surveillance
  

  A.W.Senior (Ed.) July 2009 ISBN: 978-1-84882-300-6 Springer All royalties go to WITNESS.

• Guide to Biometrics
  

  R. M. Bolle, J. H. Connell, S. Pankanti, N. K. Ratha and A. W. Senior Springer-Verlag, New York Summer 2003. ISBN 0387400893 Translated into Polish (2008) and Russian (2008)

• IEEE International Workshop on Analysis and Modelling of Faces and Gestures
  S. Gong, H. Zhang, S. Li, A. Senior, T. Vetter and W. Zhao (Eds.).
  239 pages, IEEE Computer Society, 2003. ISBN 0769520103
• IEEE International Workshop on Recognition, Analysis and Tracking of Faces and Gestures in Real Time Systems
  A. Senior (Ed.).
  184 pages, IEEE Computer Society, 2001 ISBN 0769510744

Journal papers

• Deep Learning for Acoustic Modeling in Parametric Speech Generation: A systematic review of existing techniques and future trends ,
  Zhen-Hua Ling, Shiyin Kang, Heiga Zen, Andrew Senior, Mike Schuster, Xiao-Jun Qian, Helen Meng, Li Deng in IEEE Signal Processing Magazine. Vol. 32, 2015
• A Real-Time End-to-End Multilingual Speech Recognition Architecture
  J. Gonzalez-Dominguez, D. Eustis, I. Lopez-Moreno, A. Senior, F. Beaufays, and P. J. Moreno
  in IEEE Journal of Selected Topics in Signal Processing special issue on Signal Processing for Big Data (SPBD) June 2015.
• Deep Neural Networks for Acoustic Modeling in Speech Recognition
  G. Hinton, L. Deng, D. Yu, G. Dahl, A. Mohamed, N. Jaitly, A. Senior, V. Vanhoucke, P. Nguyen, T. Sainath, and B. Kingsbury
  in IEEE Signal Processing Magazine. Vol. 29, No. 6, November, 2012
• Robust and efficient foreground analysis in complex surveillance videos
  Y.L. Tian, A. Senior, M. Lu
  Machine Vision and Applications, 2011 pp. 1-17
• IBM Smart Surveillance System (S3): Event Based Video Surveillance System with an Open and Extensible Framework
  Y.L. Tian, A. Senior, A. Hampapur, L. Brown, C. Shu, M. Lu
  Machine Vision and Applications, 2008 Vol 19. No 5-6 pp. 315-327
• Joint Face and Head Tracking inside Multi-Camera Smart Rooms
  Z. Zhang, G. Potamianos, A. W. Senior, T. S. Huang
  in Signal, Image and Video Processing Special Issue on Multi Sensor Object Detection and Tracking, pp 163-178 V.1 No.2 June 2007, Springer, London
• Appearance Models for Occlusion Handling
  A. Senior, A. Hampapur, Y.-L. Tian, L. Brown, S. Pankanti, R. Bolle
  in Journal of Image and Vision Computing Volume 24 Issue 11, pp 1233-1243 November 2006
• Enabling Video Privacy through Computer Vision
  A. Senior, S. Pankanti, A. Hampapur, L. Brown, Y.-L. Tian, A. Ekin, J. Connell, C.-F. Shu, M.Lu
  IEEE Security & Privacy V. 3 No.5 May/June 2005.
• Multi-scale Tracking for Smart Video Surveillance
  A. Hampapur, L. Brown, J. Connell, A. Ekin, N. Haas, M. Lu, H. Merkl, S. Pankanti, A. Senior, C.-F. Shu, Y.-L. Tian
  In IEEE Transactions on Signal Processing Volume 22, No. 2 March 2005
• Recent Advances in the Automatic Recognition of Audiovisual Speech
  G. Potamianos, C. Neti, G. Gravier, A. Garg, and A.W.Senior
  in Proceedings of the IEEE Vol. 91 No. 9 September 2003 pp. 1306-1326 (invited paper).
• A Combination Fingerprint Classifier
  A.W.Senior
  in IEEE Transactions on Pattern Analysis and Machine Intelligence Vol. 23 No. 10 October 2001 pp. 1165-1174.
• Improved Fingerprint Matching by Distortion Removal
  A.W. Senior, R. Bolle
  In IEICE Transactions on Information and Systems, special issue on biometrics. Volume E84-D No. 7 July 2001 pp. 825-832
• A cascade visual front end for speaker independent automatic speechreading
  G.Potamianos, C. Neti, G.Iyengar, A.Senior, A.Verma
  in International Journal of Speech Technology. Volume 4, Issue 3/4 July 2001 pp 193-208.
• Audio-visual speaker recognition for video broadcast news: Some fusion techniques
  B.Maison, C. Neti, A.Senior.
  Invited paper in Journal of VLSI Signal Processing special issue on Multimedia Volume 29 No. 1/2, 2001.
• An Off-line Cursive Handwriting Recognition System.
  A.W.Senior and A.J.Robinson
  IEEE Transactions on Pattern Analysis and Machine Intelligence Vol. 20 No. 3 March 1998 pages 309-321.

Book chapters

• Face privacy in automated systems
  A. Senior, S. Pankanti
  invited chapter in Handbook of Face Recognition 2nd Edition 2011 Ed. Anil Jain & Stan Li, Springer.
• Computer Vision Interfaces for Interactive Art
  A. Senior, A. Jaimes
  in Human-Centric Interfaces for Ambient Intelligence, Elsevier (2009)
• An Introduction to Automatic Video Surveillance
  A. Senior
  in Protecting Privacy in Video Surveillance, 2009. pp 1-9
• Privacy protection in a video surveillance system
  A. Senior
  in Protecting Privacy in Video Surveillance, 2009. pp 35-47
• Event detection, query and retrieval for video surveillance
  Y.-L. Tian, A. Hampapur, L. Brown, R. Feris, M.Lu, A. Senior, C.-F. Shu and Y.Zhai
  in Artificial Intelligence for Maximizing Content Based Image Retrieval. ed. Z.Ma Idea Group 2008
• Distributed Active Multi-camera Networks
  A. Senior, A. Hampapur, L. Brown, Y.-L. Tian, C.-F. Shu and S. Pankanti
  in Ambient Intelligence ed. P.Remagnino. G.L. Foresti and T.Ellis. Kluwer Publishing 2004. ISBN 0387229906
• Face recognition and its applications
  A.W. Senior and R.Bolle
  Chapter 4 in Biometric Solutions for Authentication in an E-World, D.Zhang ed. Kluwer Academic Publishers July 2002 ISBN 1402071426
• Fingerprint classification by Decision Fusion
  A.W. Senior and R. Bolle
  in Advances in Fingerprint Recognition ed. N.Ratha and R.Bolle. Springer-Verlag 2003 ISBN 0387955933

Other publications

• FLAT START TRAINING OF CD-CTC-SMBR LSTM RNN ACOUSTIC MODELS
  K.Rao, A. Senior and H. Sak to appear in ICASSP 2016
• ACOUSTIC MODELLING WITH CD-CTC-SMBR LSTM RNNS
  A. Senior, H. Sak, F. de Chaumont Quitry, T. Sainath, K. Rao ASRU 2015
• Speaker Location and Microphone Spacing Invariant Acoustic Modeling from Raw Multichannel Waveforms
  T.N. Sainath, R.J. Weiss, K.W. Wilson, A. Narayanan, M. Bacchiani, A. Senior ASRU 2015
• Large Vocabulary Automatic Speech Recognition for Children
  H. Liao, G. Pundak, O. Siohan, M. K. Carroll, N. Coccaro, Q.-M. Jiang, T.N. Sainath, A. Senior, F. Beaufays, and M. Bacchiani in Interspeech 2015
• Fast and Accurate Recurrent Neural Network Acoustic Models for Speech Recognition
  H. Sak, A. Senior, K.Rao, F.Beaufays in Interspeech 2015
• Learning the Speech Front-end With Raw Waveform CLDNNs
  T.N. Sainath, R.J. Weiss, A.Senior, K.W. Wilson, O. Vinyals in Interspeech 2015
• Learning Acoustic Frame Labeling for Speech Recognition with Recurrent Neural Networks
  H. Sak, A. Senior, K. Rao, O. Irsoy, A. Graves, F. Beaufays, J. Schalkwyk in ICASSP 2015
• Convolutional, Long Short-Term Memory, Fully Connected Deep Neural Networks
  T. N. Sainath, O. Vinyals, A. Senior, H. Sak in ICASSP 2015
• Context Dependent Phone Models for LSTM RNN Acoustic Modelling
  A. Senior, H. Sak, I. Shafran in ICASSP 2015
• Long Short-Term Memory Recurrent Neural Network Architectures for Large Scale Acoustic Modeling
  H. Sak, A. Senior, F. Beaufays in Interspeech 2014
• Sequence Discriminative Distributed Training of Long Short-Term Memory Recurrent Neural Networks
  H. Sak, O. Vinyals, G. Heigold A. Senior, E. McDermott, R. Monga, M. Mao in Interspeech 2014
• Asynchronous Stochastic Optimization for Sequence Training of Deep Neural Networks: Towards Big Data
  E. McDermott, G. Heigold, P. Moreno, A. Senior & M. Bacchiani in Interspeech 2014
• Asynchronous, Online, GMM-free Training of a Context Dependent Acoustic Model for Speech Recognition
  M. Bacchiani A. Senior in Interspeech 2014
• GMM-free DNN training
  A.Senior, G.Heigold, M.Bacchiani, H.Liao in ICASSP 2014
• Improving DNN speaker independence with i-vector features
  A.Senior, I.Lopez-Moreno in ICASSP 2014
• Long Short-Term Memory Recurrent Neural Network Architectures for Large Vocabulary Acoustic Modelling
  H.Sak, A.Senior, F.Beaufays 2014, on ArXiv.
• Fine context, low-rank, softplus deep neural networks for mobile speech recognition
  A.Senior, X.Lei in ICASSP 2014
• Deep Mixture Density Recurrent Neural Networks for Acoustic Modeling in Statistical Parametric Speech Synthesis
  H. Zen, A.Senior in ICASSP 2014
• Asynchronous Stochastic Optimization for Sequence Training of Deep Neural Networks
  G.Heigold, E.McDermott, V.Vanhoucke, A.Senior, M.Bacchiani in ICASSP 2014
• Large Scale Deep Neural Network Acoustic Modeling with Semi-supervised Training Data for YouTube Video Transcription
  H.Liao, E.McDermott, A.Senior in ASRU 2013
• Accurate and Compact Large Vocabulary Speech Recognition on Mobile Devices
  X.Lei, A.Senior, A.Gruenstein, J.Sorenson in Interspeech 2013.
• On Rectified Linear Units for Speech Processing ,
  M.D. Zeiler M. Ranzato, R. Monga, M.Mao, K.Yang, Q.V.Le, P.Nguyen, A. Senior, V.Vanhoucke, J.Dean, G.E.Hinton, in ICASSP 2013.
• Statistical Parametric Speech Synthesis Using Deep Neural Networks ,
  Heiga Zen, Andrew Senior, Mike Schuster in ICASSP 2013.
• An Empirical Study of Learning Rates in Deep Neural Networks for Speech Recognition ,
  A. Senior, G. Heigold, M. Ranzato, K. Yang in ICASSP 2013.
• Multilingual Acoustic Models Using Distributed Deep Neural Networks ,
  G. Heigold, V. Vanhoucke, A. Senior, P. Nguyen, M., M. Devin, J. Dean in ICASSP 2013.
• * Large Scale Distributed Deep Networks ,
  Jeffrey Dean, Greg S. Corrado, Rajat Monga, Kai Chen, Matthieu Devin, Quoc V. Le, Mark Z. Mao, Marc'Aurelio Ranzato, Andrew Senior, Paul Tucker, Ke Yang, Andrew Y. Ng in NIPS 2012.
• Application of Pretrained Deep Neural Networks to Large Vocabulary Speech Recognition,
  N. Jaitly, P. Nguyen, A. W. Senior, V. Vanhoucke
  in Interspeech 2012.
• Learning Improved Linear Feature Transformations for Speech Recognition
  A. Senior, Y. Cho, J. Weston
  to appear in ICASSP 2012
• Improving the speed of neural networks on CPUs
  V. Vanhoucke, A. Senior, M. Mao
  in NIPS Workshop on deep learning 2011
• Translation-Inspired OCR
  D.Genzel, A.C. Popat, N. Spasojevic, M. Jahr, A. Senior, E. Ie, F. Y.-F. Tang
  in International Conference on Document Analysis and Recognition. 2011, Beijing.
• Interactive motion analysis for video surveillance and long term scene monitoring
  A Senior, YL Tian, M Lu
  in Visual Surveillance 2010 at ACCV 2010 Workshops, pp. 164-174
• Video analytics for retail
  A.W. Senior, L. Brown, A. Hampapur, C.-F.Shu, Y. Zhai, R.S. Feris, Y.-L. Tian, S.Borger, C.Carlson
  In Special session on Video systems for retail applications Advanced Video and Sensor-based Surveillance. 2007, London.
• Searching Surveillance Video
  A. Hampapur, L. Brown, R.S. Feris, A.W. Senior, C.-F. Shu, Y.-L. Tian, Y. Zhai, M. Lu
  In Industrial special session Advanced Video and Sensor-based Surveillance. 2007, London.
• S3: The IBM Smart Surveillance System: From transactional systems to observational systems
  A. Hampapur, S.Borger, L. Brown, C. Carlson, J. Connell, M. Lu, A.W.Senior, V.Reddy, C.-F.Shu, Y.-L.Tian
  Invited paper in Special Session on Distributed Processing in Image Sensor Networks. International Conference on Speech and Signal Processing 2007, Hawaii.
• Visual Person Searches for Retail Loss Detection: Application and Evaluation
  A.W.Senior, L. Brown, C.-F.Shu, Y.-L.Tian, M. Lu, Y. Zhai, A. Hampapur
  In International Conference on Vision Systems 2007, Bielefeld, Germany.
• Video Privacy in the Era of Automated Surveillance
  L. M. Brown, S. Velipasalar, A. W. Senior, S. Pankanti, A. Hampapur, C.-F. Shu, Y.-L. Tian
  In Proceedings of IEEE workshop on Privacy Research in Vision 2006.
• A Comparison of Multi-camera Person Tracking Algorithms
  A.W.Senior, G.Potamianos, S.Chu, Z.Zhang, A. Hampapur
  In Proceedings of Visual Surveillance 2006.
• Presence/Absence: The 2005 ACM Multimedia Interactive Art Exhibition
  A. Senior, A. Jaimes, W. Muench
  In IEEE Multimedia Jan 2006.
• ACM Multimedia Interactive Art Program: An Introduction to the Presence/Absence Exhibition
  A. Jaimes, A. Senior, W. Muench
  In Proceedings of ACM Multimedia Conference 2005.
• IBM Smart Surveillance System (S3): A Open And Extensible Framework For Event Based Surveillance
  L. Brown, J. Connell, A. Hampapur, M. Lu, A. Senior, C.-F. Shu, Y. Tian
  In Proceedings of the International Conference on Advanced Video- and Signal-based Surveillance September 2005.
• A Joint System For Person Tracking and Face Detection
  Z. Zhang, G. Potamianos, A. Senior, S. Chu and T. Huang
  In Proceedings of HCI workshop, ICCV 2005.
• Acquiring Multi-Scale Images by Pan-Tilt-Zoom Control and Automatic Multi-Camera Calibration
  A. Senior, A. Hampapur
  In Workshop on Applications of Computer Vision Jan. 2005.
• Performance Evaluation of Surveillance Systems Under Varying Conditions
  Lisa M. Brown, Andrew W. Senior, Ying-li Tian, Jonathan Connell, Arun Hampapur, Chiao-fe Shu, Hans Merkl, and Max Lu
  In IEEE Int'l Workshop on Performance Evaluation of Tracking and Surveillance Jan. 2005.
• Shibboleth: Exploring cultural boundaries in speech
  A. Senior
  In proceedings of ACM Multimedia 2004 Interactive Art Program. pp. 1003-4
• Blinkering Surveillance: Enabling Video Privacy through Computer Vision
  A. Senior, S. Pankanti, A. Hampapur, L. Brown, Y.-L. Tian, A. Ekin
  IBM Technical Report RC22886 2003.
• Detection and Tracking in the IBM PeopleVision System
  J. Connell, A.W. Senior, A. Hampapur, Y.-L. Tian, L. Brown, S. Pankanti
  IEEE ICME Taiwan June 2004.
• Smart Surveillance: Applications, Technologies and Implications
  A. Hampapur, L. Brown, J. Connell, S. Pankanti, A.W. Senior, and Y.-L. Tian
  IEEE Pacific-Rim Conference On Multimedia, Singapore, Dec. 2003.
• Real-Time Articulated Human Body Tracking using Silhouette Information
  A.W. Senior
  in proceedings IEEE Workshop on Visual Surveillance/PETS, Nice, France, October 2003.
• Absolute Head Pose Estimation From Overhead Wide-Angle Cameras
  Y-L. Tian, L. Brown, J. Connell, S. Pankanti, A. Hampapur, A. Senior, and R. Bolle
  IEEE International Workshop on Analysis and Modeling for Face and Gestures, Nice, France, Oct. 2003.
• Face Cataloger: Multi-Scale Imaging for Relating Identity to Location
  A. Hampapur, S. Pankanti, A.W. Senior, Y-L Tian, L. Brown, and R. Bolle
  in proceedings IEEE conference on Advanced Video and Signal Based Surveillance, Miami, FL. July 21-22, 2003.
• Real World Real-time Automatic Recognition of Facial Expressions
  Y-L. Tian, L. Brown, A. Hampapur, S. Pankanti, A. W. Senior, and R. M. Bolle
  in proceedings IEEE workshop on performance evaluation of tracking and surveillance, Graz, Austria. March 31, 2003
• PeopleVision: Privacy Protection in Visual Surveillance
  S. Pankanti, A. Senior, L. Brown, A. Hampapur, Y.-L. Tian, and R. Bolle
  IEEE Pervasive Computing Work in Progress Volume 2 No. 1, January-March 2003. p. 96
  
• Autonomic User Interfaces
  A. Hampapur, A. W. Senior, S. Pankanti, Y.-L. Tian, Gopal S. Pingali, R. M. Bolle
  IBM Technical Report RC22542 August 2002.
• Tracking with Probabilistic Appearance Models
  A. W. Senior
  in proceedings ECCV workshop on Performance Evaluation of Tracking and Surveillance Systems 1 June 2002 pp 48-55.
• Fingerprint Minutiae: A Constructive Definition
  R. M. Bolle, A. W. Senior, N. K. Ratha, S. Pankanti,
  in proceedings ECCV workshop on Biometrics. Springer LNCS Volume 2359 pp.58-66 1 June 2002
• Appearance Models for Occlusion Handling
  A.Senior, A.Hampapur, Y-L Tian, L. Brown, S. Pankanti, R. Bolle
  in proceedings of Second International workshop on Performance Evaluation of Tracking and Surveillance systems in conjunction with CVPR'01 December 2001.
• Tutorial on Automated Biometrics
  N. Ratha, A.W.Senior
  in Proceedings of International Conference on Advances in Pattern Recognition, Rio de Janiero, Brazil, March 2001.
• Virtual Garden: A Vision-based Multimedia Installation
  A.Senior.
  In Proceedings of ACM Multimedia 2000 Workshop Bridging the Gap: Bringing Together New Media Artists and Multimedia Technologists.
• Perceptual Interfaces for Information Interaction: Joint processing of audio and visual information for human-computer interaction
  C. Neti, G.Iyengar, G.Potamianos, A.Senior, B.Maison
  Invited paper in proceedings of ICSLP Vol III pp. 11-14, Beijing October 2000.
• Joint processing of audio and visual information for multimedia indexing and human-computer interaction
  C. Neti, B.Maison, A.Senior, G.Iyengar, P.Decuetos, S.Basu, A.Verma
  presented at RIAO, December 2000.
• Audio-Visual Intent to Speak Detection for Human-Computer Interaction
  P. de Cuetos C. Neti, A. Senior
  presented at ICASSP 2000, Istanbul 2000.
• Late Integration in Audio-visual Continuous Speech Recognition
  A. Verma, T. Faruquie, C. Neti, S. Basu, A. Senior.
  in proceedings of Automatic Speech Recognition and Understanding Colorado, 12-15 December 1999.
• Pose Compensation for Bimodal Speech Recognition
  J. Ma, C. Neti, A. Senior
  in proceedings of Automatic Speech Recognition and Understanding 1999 Colorado, 12-15 December 1999.
• Minutia Template Exchange Format.
  R. M. Bolle, N. K. Ratha, A. Senior and S. Pankanti.
  In proceedings of IEEE Workshop on Automatic Identification Advanced Technologies pp. 74-77. Summit, New Jersey 28-29 October 1999.
• Audio-visual Large Vocabulary Continuous Speech Recognition in the Broadcast Domain
  S. Basu, C. Neti, N. Rajput, A. Senior, L. Subramaniam, A. Verma
  in Proceedings of IEEE Multimedia Signal Processing. Copenhagen, 13-15 September 1999.
• Audio-visual speaker Recognition for video broadcast news: some fusion techniques
  B. Maison, C. Neti and A. Senior.
  In Proceedings of IEEE Multimedia Signal Processing. Copenhagen, 13-15 September 1999.
• Recognizing faces in broadcast video.
  A. Senior.
  in proceedings of IEEE International Workshop on Recognition, Analysis, and Tracking of Faces and Gestures in Real-Time Systems ICCV 1999.
• On the use of visual information for improving audio-based speaker recognition
  A. Senior, C. Neti and B. Maison.
  In proceedings of Audio Visual Speech Processing, Santa Cruz, California, 7-9 August 1999.
• Face and Feature Finding for a Face Recognition System
  A.W.Senior
  In proceedings of Audio- and Video- based Biometric Person Authentication '99 pp. 154-159. Washington D. C. USA, March 22-24, 1999
• Audio-visual speaker recognition for video broadcast news
  C.Neti and A.W.Senior
  in proceedings DARPA Broadcast News HUB4 Workshop, Washington D.C., March 1999 pp 139-142.
• A Hidden Markov Model Fingerprint Classifier.
  A.W.Senior
  In proceedings of the 1997 IEEE Asilomar conference on Signals, Systems and Computers. pages 306-310.
• Writer Adaptation of an HMM handwriting recognition system.
  A.W.Senior and K.S.Nathan
  In proceedings of the International Conference on Acoustics, Speech and Signal Processing 1997.
• Initialization of Hidden Markov Models for Unconstrained On-line Handwriting Recognition.
  K.S.Nathan, A.W.Senior and J.Subrahmonia
  In International Conference on Acoustics, Speech and Signal Processing 1996, pages 3503-6.
• Duration Modelling for an On-line Handwriting Recognizer.
  A.W.Senior, K.S.Nathan and J.Subrahmonia
  In International Conference on Acoustics, Speech and Signal Processing 1996, pages 3483-6.
• Forward-Backward retraining of recurrent neural networks.
  A.W.Senior and A.J.Robinson
  in Advances in Neural Information Processing Systems Volume 8, 1996, pages 743-749.
• Off-line Cursive Handwriting Recognition Using Recurrent Neural Networks. (link to abstract)
  A.W.Senior
  PhD thesis, Cambridge University 1994.
• Using Constrained Snakes for Feature Spotting in Off-line Cursive Script.
  A.W.Senior and F.Fallside
  In proceedings of the International Conference on Document Analysis and Recognition pages 305-310. Tsukuba, Japan, October 1993.
• Normalisation and preprocessing for a recurrent network off-line handwriting recognition system.
  A.W.Senior
  In Fundamentals of Handwriting Recognition, ed. Sebastiano Impedovo. Springer Verlag 1994. Pages 360-5.
• A Recurrent Network Approach to the Automatic Reading of Handwriting.
  A.W.Senior
  Invited paper at Netherlands Historic Data Archive workshop on `OCR in the Historical Discipline' Leiden, The Netherlands, June 1993. In proceedings of VIII International Conference of the Association for History and Computing pages 59-65.
• An Off-line Cursive Script Recognition System Using Recurrent Error Propagation Networks
  A.W.Senior and F.Fallside
  in proceedings of International Workshop on Frontiers in Handwriting Recognition pages 132-141. Buffalo, USA, May 1993.
• Off-line Handwriting Recognition: A Review and Experiments.
  A.W.Senior and F.Fallside
  Technical Report 105, Cambridge University Engineering Department, December 1992.
• Off-line Handwriting Recognition using Recurrent Error Propagation Networks.
  A.W.Senior and F.Fallside
  In proceedings of British Machine Vision Conference. Leeds, UK, September 1992 pages 453-461.
• Reconnaissance de Parole Continue par Modèles Markoviens Cachées.
  A.W.Senior
  Technical report. Laboratoire d'Informatique et Méchanique pour les Sciences de l'Ingénieur (LIMSI) Paris, September 1991.