Dr Sim Khe Chai

Dr Sim Khe Chai

CSIDM-200806

Designation: Assistant Professor, National University of Singapore
Email: kcs23@cantab.net
Homepage: http://www.comp.nus.edu.sg/~simkc

Dr. Sim Khe Chai is jointly appointed as an Assistant Professor at the School of Computing (SoC), National University of Singappore (NUS) and as a research engineer at the Institute for Infocomm Research (I2R), one of the research institutes of Agency for Science, Technology and Research (A*STAR). He received the B.A. and M.Eng degrees in Electrical and Information Sciences from the University of Cambridge, England in 2001. He worked on the Application Programming Interface (API) for Hidden Markov Model Toolkit (HTK) (known as the ATK) for his Undergraduate final year project under the supervision of Prof. Steve Young. He was then awarded the Gates Cambridge Scholarship to pursue the course of Computer Speech, Text and Internet Technology (CSTIT) at the same university. He completed his M.Phil dissertation "Covariance Matrix Modelling using Rank-One Matrices" in 2002 under the supervision of Dr. Mark Gales. He joined the Machine Intelligence Laboratory (MIL) (formerly the Speech, Vision and Robotics (SVR) group), Cambridge University Engineering Department in the same year as a research student, supervised by Dr. Mark Gales. He received his Ph.D degree in July 2006. He is also an alumni of Churchill College. His main research interest is in statistical pattern classification and acoustic modelling for automatic speech recognition. He also worked on the DARPA funded Effective, Affordable and Reusable Speech-to-text (EARS) project from 2002-2005 and the Global Autonomous Language Exploitation (GALE) project between 2005 and 2006. He was also in the IIR team which participated in the NIST 2007 Language recognition Evaluation (LRE) and the NIST 2008 Speaker Recognition Evaluataion (SRE).

Research

Interests Statistical pattern classification, machine learning, speech recognition, speaker recognition, language recognition

Academic Experience

Cambridge University, UK Research Student
October 2002 – May 2006

  • Responsibilities: ** Ph.D. research on precision matrix modeling for speech recognition ** Participated in DARPA funded EARS & GALE projects ** Shared responsibilities in LVCSR system development –
  • Languages: English & Mandarin
  • Domain: Broadcast News & Conversational Telephone Speech
  • Major contributions: ** Participated in 2003 & 2004 NIST Rich Transcription Evaluations (RT03 & RT04) ** Contributed a discriminatively trained precision matrix model to the RT04 Evaluation

Cambridge University, UK Teaching Assistant
May 2006 – July 2006

  • Supervised Undergraduate & Masters students in Mechanics, C/C++ & Matlab/Octave computing courses. Shared responsibilities examinations, laboratory assignments & grades.

Industrial Experience

Institute for Infocomm Research, Singapore Research Engineer
October 2006 – present

  • Responsibilities: ** Research work in speech, speaker and language recognition ** Co-supervise students from NUS & NTU ** Participation in the 2007 NIST Language Recognition Evaluation ** Participation in the 2008 NIST Speaker Recognition Evaluation

Journal Publications

  • Khe Chai SIM and H. Li, “On Acoustic Diversification Front-end for Spoken Language Identification”, IEEE Transactions on Audio, Speech and Language Processing, July 2008
  • Khe Chai SIM and M. J. F. Gales, “Discriminative Semi-parametric Trajectory Models for Speech Recognition”, Computer Speech and Language, May 2007
  • Khe Chai SIM and M. J. F. Gales, “Minimum Phone Error Training of Precision Matrix Models”, IEEE Transactions on Audio, Speech and Language Processing, May 2006

Selected Conference Papers

  • Khe Chai SIM and H. Li, “Context-sensitive Probabilistic Phone Mapping Model for Cross-lingual Speech Recognition” in Proc. Interspeech 2008
  • Khe Chai SIM and H. Li, “Robust Phone Set Mapping using Decision Tree Clustering for Cross-lingual Phone Recognition”, in Proc. IEEE ICASSP 2008, Las Vegas, USA, April 2008
  • Khe Chai SIM and H. Li, “Fusion of Contrastive Models for Parallel Phonotactic Spoken Language Identification”, in Proc. Interspeech 2007, Antwerp, Belgium.
  • H. Li, Khe Chai SIM, J. Kuo and M. Dong, “Semantic Transliteration of Personal Names”, 45th Annual Meeting of the ACL, Prague, Czech Republic, June 2007.
  • Khe Chai SIM, W. Byrne, M. J. F. Gales, H. Sahbi and P. Woodland “Consensus Network Decoding for Statistical Machine Translation System Combination”, in Proc IEEE ICASSP, Honolulu, Hawaii, USA, April 2005.
  • Khe Chai SIM and M. J. F. Gales, “Temporally Varying Model Parameters for Large Vocabulary Continuous Speech Recognition”, in Proc Interspeech 2005, Lisbon, Portugal.
  • Khe Chai SIM and M. J. F. Gales, “Adaptation of Precision Matrix Models on Large Vocabulary Continuous Speech Recognition”, in Proc IEEE ICASSP, Philadelphia, USA, March 2005
  • X. Liu, M. J. F. Gales, Khe Chai SIM and K. Yu, “Investigation of Acoustic Modelling Techniques for LVCSR Systems”, in Proc IEEE ICASSP, Philadelphia, USA, March 2005
  • D. Y. Kim, H. Y. Chan, G. Evermann, M. J. F. Gales, D. Mrva, Khe Chai SIM and P. C. Woodland, “Development of the CU-HTK 2004 Broadcast News Transcription Systems”, in Proc IEEE ICASSP, Philadelphia, USA, March 2005
  • Khe Chai SIM and M. J. F. Gales, “Basis Superposition Precision Matrix Modelling for Large Vocabulary Continuous Speech Recognition”, in Proc IEEE ICASSP, Montreal, Quebec, Canada, 2004.