``Numerical Solution for Linear Programming Problems Using an Affine-Scaling Method (in Japanese),''
Department of Applied Mathematics, Tokyo University of Science, February 1999.
``A Study on Low Bit Rate Speech Coder Using Mixed Excitation (in Japanese),''
Department of Computational Intelligence and Systems Science, Tokyo Institute of Technology, February 2001.
This paper proposes a low bit rate speech coder at 1.6 kbps. The coder uses mixed excitation which is a mixture of a periodic pulse and white noise, and mel-generalized cepstral analysis for spectral estimation. To improve the coded speech quality, we study about pitch analysis, mixture method, and gain analysis. Furthermore, we introduce jitter to a periodic pulse, periodically emphasis of noise component, and variable mel-generalized cepstral coefficients order. The result of subjective evaluation test shows that the proposed coder at 1.6 kbps is almost as good as MELP at 2.4 kbps for female speech.
``Estimation of Articulatory Movements from Speech Signal Using an HMM-Based Speech Production Model,''
Department of Information Processing, Tokyo Institute of Technology, August 2006. [abstract]