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SHIMAMURA Tetsuya
Mathematics, Electronics and Informatics DivisionProfessor
Department of Information and Computer Sciences

Performance information

■ MISC
  • Equalization of Time-Variant Communications Channels via Adaptive AR Prefiltering               
    Shimamura T
    First page:327, Last page:331, 2009
    DOI:https://doi.org/10.1109/CSIE.2009.250
    DOI ID:10.1109/CSIE.2009.250
  • Dual Adaptive Pre-Whitening Filters for LMS Algorithm               
    Tashiro K; Shimamura T
    First page:1, Last page:4, 2009
  • Time Delay Estimation of Arrival and Spectrum Subtraction for Acoustic Dual-Microphone Systems               
    Nakamura N; Ikeda T; Shimamura T
    First page:165, Last page:168, 2009
  • Image Restoration via Wiener Filtering with Improved Noise Estimation               
    Furuya H; Eda S; Shimamura T
    First page:315, Last page:320, 2009
  • Image Restoration via Wiener Filtering in the Frequency Domain               
    Furuya H; Eda S; Shimamura T
    Volume:5, Number:Issue 2, First page:63, Last page:73, 2009
  • Equalization of time-variant communications channels via adaptive AR prefiltering               
    Tetsuya Shimamura
    2009 WRI World Congress on Computer Science and Information Engineering, CSIE 2009, Volume:6, First page:327, Last page:331, 2009
    For the purpose of time-variant channel equalization, a novel structure of equalizer is proposed. An autoregressive (AR) filter is used as the prefilter and a finite impulse response (FIR) filter is cascaded. The AR prefilter is constructed from channel estimation results adaptively, and the cascaded FIR filter behaves as an adaptive FIR equalizer. It is shown that the resulting infinite impulse response (IIR) equalizer is closely related with the IIR-type Wiener filter. Simulations demonstrate that the proposed equalizer provides better performance than the FIR equalizer with the least mean square adaptation in time-variant environments. © 2008 IEEE.
    English
    DOI:https://doi.org/10.1109/CSIE.2009.250
    DOI ID:10.1109/CSIE.2009.250, SCOPUS ID:71049116017
  • Dual Adaptive Pre-Whitening Filters for LMS Algorithm               
    Tashiro K; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:1, Last page:4, 2009
  • Time Delay Estimation of Arrival and Spectrum Subtraction for Acoustic Dual-Microphone Systems               
    Nakamura N; Ikeda T; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:165, Last page:168, 2009
  • Image Restoration via Wiener Filtering with Improved Noise Estimation               
    Furuya H; Eda S; Shimamura T
    Proceedings of WSEAS International Conference on Signal Processing, Robotics and Automation, First page:315, Last page:320, 2009
  • Image Restoration via Wiener Filtering in the Frequency Domain               
    Furuya H; Eda S; Shimamura T
    WSEAS Transactions on Signal Processing, Volume:5, Number:Issue 2, First page:63, Last page:73, 2009
  • Amplitude Banded Technique and Parallel Structure for Godard and Sato Algorithms of Blind Channel Equalization               
    Khan, M.L.R; Wondimagegnehu M.H; Shimamura T
    First page:768, Last page:772, 2008
    DOI:https://doi.org/10.1109/ICCITECHN.2008.4803015
    DOI ID:10.1109/ICCITECHN.2008.4803015
  • An Efficient and Effective Variable Step Size NLMS Algorithm               
    Takekawa H; Shimamura T; Jimaa S
    First page:1640, Last page:1643, 2008
    DOI:https://doi.org/10.1109/ACSSC.2008.5074702
    DOI ID:10.1109/ACSSC.2008.5074702
  • Convergence Evaluation of a Variable Step-Size LMSE Adaptive Switching Algorithm               
    Jimaa S; Shimamura T; Takekawa H
    First page:23, Last page:26, 2008
    DOI:https://doi.org/10.1109/INCC.2008.4562685
    DOI ID:10.1109/INCC.2008.4562685
  • Iterative Cross-Correlation Method for Time Delay Estimation               
    Nakamura N; Shimamura T
    First page:387, Last page:390, 2008
  • Wavelet Based Denoising for Images Degraded by Poisson Noise               
    Shimamura T; Eda S; Ito T; Kuwano Y; Takahashi Y
    First page:436, Last page:440, 2008
  • 騒音環境下に有効な骨導・気導一体型マイクロホン               
    島村徹也
    First page:11, Last page:16, 2008
  • 双対の適応白色化フィルタを用いたLMSアルゴリズム               
    田代和義; 島村徹也
    First page:195, Last page:200, 2008
  • 線形予測誤差を用いた骨導音声の品質改善               
    杉山貴紀; 島村徹也; 八嶋弘幸
    First page:164, Last page:169, 2008
  • Special Section on Papers Awarded the Student Paper Award at NCSP'08 Editor's Note               
    Shimamura T
    Volume:12, Number:4, First page:269, Last page:270, 2008
  • Special Section on Nonlinear Circuits and Signal Processing Editor's Note               
    Shimamura T
    Volume:12, Number:6, First page:412, Last page:413, 2008
  • Amplitude Banded Technique and Parallel Structure for Godard and Sato Algorithms of Blind Channel Equalization               
    Khan, M.L.R; Wondimagegnehu M.H; Shimamura T
    Proceedings of International Conference on Computer and Information Technology, First page:768, Last page:772, 2008
    DOI:https://doi.org/10.1109/ICCITECHN.2008.4803015
    DOI ID:10.1109/ICCITECHN.2008.4803015
  • High Pitch Source Isolation Using Complex Cepstrum in the Autocorrelation Domain               
    Bisrat Derebssa; Tetsuya Shimamura
    2008 IEEE ASIA PACIFIC CONFERENCE ON CIRCUITS AND SYSTEMS (APCCAS 2008), VOLS 1-4, First page:1284, Last page:1287, 2008
    This paper proposes a technique for improving the performance of linear predictive analysis by using homomorphic deconvolution. Estimating the vocal tract transfer function using linear prediction is often inaccurate when the speaker speaks with a high pitch. This is due to the convolution of the glottal output signal, which is a periodic impulse, with the vocal tract impulse response. We propose a method that will remove this convolution by using complex cepstrum homomorphic deconvolution in the autocorrelation domain. The technique has been tested for synthetic and natural speech of varying pitch frequency and has improved performance on formant frequency estimation than a similar technique proposed recently.
    IEEE, English
    DOI:https://doi.org/10.1109/APCCAS.2008.4746262
    DOI ID:10.1109/APCCAS.2008.4746262, Web of Science ID:WOS:000268007100317
  • An Efficient and Effective Variable Step Size NLMS Algorithm               
    Takekawa H; Shimamura T; Jimaa S
    Proceedings of Asilomar Conference on Signals, Systems and Computers, First page:1640, Last page:1643, 2008
    DOI:https://doi.org/10.1109/ACSSC.2008.5074702
    DOI ID:10.1109/ACSSC.2008.5074702
  • Adaptive Line Enhancer for Time Delay Estimation of Ultrasonic Echoes               
    Chayanin Tiengwattanatum; Nakamura Naoyuki; Tetsuya Shimamura
    2008 INTERNATIONAL SYMPOSIUM ON COMMUNICATIONS AND INFORMATION TECHNOLOGIES, First page:368, Last page:371, 2008
    A new method of time delay estimation for ultrasonic echoes in noisy environment is proposed. By using the least mean square algorithm for adaptive line enhancer as a pre-filter and following by a cross correlator can achieve better performance than the conventional method. Computer simulations results confirm the superiority of the proposed method even at very low signal-to-noise ratios.
    IEEE, English
    DOI:https://doi.org/10.1109/ISCIT.2008.4700215
    DOI ID:10.1109/ISCIT.2008.4700215, Web of Science ID:WOS:000265524600073
  • Amplitude-Division Parallel LMS Estimator               
    Tetsuya Shimamura; Shingo Oikawa; Yusuke Tsuda
    2008 51ST MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2, First page:950, Last page:953, 2008
    This paper presents a novel tracking technique for rapidly time-varying channels. The proposed scheme supposes multiple linear transversal filters (estimators), which are constructed in a parallel structure. The coefficient vectors for each estimator are adapted by the least mean square (LMS) algorithm according to the information of the channel coefficient values. Computer simulation results show that the proposed estimator provides an improvement relative to the conventional prediction based LMS estimators in various fade rate conditions.
    IEEE, English
    DOI:https://doi.org/10.1109/MWSCAS.2008.4616958
    DOI ID:10.1109/MWSCAS.2008.4616958, ISSN:1548-3746, Web of Science ID:WOS:000261729500238
  • Convergence Evaluation of a Variable Step-Size LMSE Adaptive Switching Algorithm               
    Jimaa S; Shimamura T; Takekawa H
    Proceedings of IEEE International Networking and Communications Conference, First page:23, Last page:26, 2008
    DOI:https://doi.org/10.1109/INCC.2008.4562685
    DOI ID:10.1109/INCC.2008.4562685
  • Iterative Cross-Correlation Method for Time Delay Estimation               
    Nakamura N; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:387, Last page:390, 2008
  • Wavelet Based Denoising for Images Degraded by Poisson Noise               
    Shimamura T; Eda S; Ito T; Kuwano Y; Takahashi Y
    Proceedings of IASTED International Conference on Biomedical Engineering, First page:436, Last page:440, 2008
  • 騒音環境下に有効な骨導・気導一体型マイクロホン               
    島村徹也
    ナノ材料・IT新技術説明会資料集, First page:11, Last page:16, 2008
  • 双対の適応白色化フィルタを用いたLMSアルゴリズム               
    田代和義; 島村徹也
    信号処理シンポジウム講演論文集, First page:195, Last page:200, 2008
  • 線形予測誤差を用いた骨導音声の品質改善               
    杉山貴紀; 島村徹也; 八嶋弘幸
    信号処理シンポジウム講演論文集, First page:164, Last page:169, 2008
  • Special Section on Papers Awarded the Student Paper Award at NCSP'08 Editor's Note               
    Shimamura T
    Journal of Signal Processing, Volume:12, Number:4, First page:269, Last page:270, 2008
  • Special Section on Nonlinear Circuits and Signal Processing Editor's Note               
    Shimamura T
    Journal of Signal Processing, Volume:12, Number:6, First page:412, Last page:413, 2008
  • Image Denoising for Poisson Noise by Pixel Values Based Division and Wavelet Shrinkage               
    Eda S; Shimamura T
    First page:441, Last page:444, 2007
  • Equalization with Amplitude Banded LMS Adaptation for Stationary Channels               
    Shimamura T
    First page:576, Last page:205, 2007
  • Performance of the Amplitude Banded LMS Equalizer on Stationary Channels               
    Shimamura T
    First page:289, Last page:292, 2007
  • Adaptive Non-Linear Prediction with Order Statistics for Speech in Impulsive Noise               
    Tanaka H; Ohhashi Y; Shimamura T
    First page:125, Last page:129, 2007
  • Discrete Cosine Transform Domain Parallel LMS Equalizer               
    Mohammed H.W; Shimamura T
    First page:119, Last page:124, 2007
  • 癒し音楽における1/fゆらぎと高周波成分との関連性               
    島村徹也; 小花あゆみ
    Volume:26, First page:25, Last page:30, 2007
  • 音声信号の非線形予測と信号表現に関する研究               
    島村徹也
    Volume:5 (18年度), First page:602, Last page:603, 2007
  • 効率的な時間遅延推定のための間接的差分関数法               
    中村尚之; 島村徹也
    First page:401, Last page:405, 2007
  • 可変ステップサイズ正規化LMSアルゴリズムの一提案               
    竹川英樹; 島村徹也
    First page:466, Last page:471, 2007
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    2007
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    Volume:6, First page:11, Last page:18, 2007
  • Magnitude Spectral Subtraction with DFTLMS Algorithm for Adaptive Line Enhancer               
    Tiengwattanatum C; Mohammed H.W; Shimamura T
    First page:213, Last page:216, 2007
  • Performance of Adaptive Nonlinear Predictor with Order Statistics in Impulsive Noise               
    Tanaka H; Ohhashi Y; Shimamura T
    Volume:2, 2007
  • Quality Improvement of Bone-Conducted Speech Using Linear Prediction Analysis Filter               
    Sugiyama T; Shimamura T; Yashima H
    First page:291, Last page:294, 2007
  • Indirect Cross-Correlation Method for Time Delay Estimation               
    Nakamura N; Shimamura T
    First page:74, Last page:77, 2007
  • Complementary and Phase Banded LMS Equalizers for Rapidly Time-Varying Channels               
    Mohammed H.W; Shimamura T
    Volume:11, First page:51, Last page:60, 2007
  • A Parallel Equalizer with LMS Adaptation in Discrete Cosine Transform Domain               
    Mohammed H.W; Shimamura T
    Volume:2, 2007
  • Restoration of Bone-Conducted Speech with the Wiener Filter and Long-Term Spectra               
    Kamata K; Yamashita K; Shimamura T; Furukawa T
    First page:583, Last page:586, 2007
  • Bone-Conducted Speech for Speaker Verification               
    Iijima S; Shimamura T
    First page:172, Last page:175, 2007
  • AMPLITUDE BANDED SATO ALGORITHM FOR BLIND CHANNEL EQUALIZATION               
    Muhammad Lutfor Rahman Khan; Mohammed H. Wondimagegnehu; Tetsuya Shimamura
    ICSPC: 2007 IEEE INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATIONS, VOLS 1-3, PROCEEDINGS, First page:1463, Last page:1466, 2007
    In this paper we propose a novel non-linear blind adaptive algorithm called the Amplitude Banded Sato (ABSato) algorithm for equalization of communication channels. The ABSato algorithm is derived as a modified version of the Amplitude Banded Least Mean Square (ABLMS) algorithm addressed by Shimamura et al. recently The capability of nonlinear classification the ABLMS algorithm inherently possesses is kept in the ABSato algorithm, resulting in an improvement of equalization performance. Mean square error as well as bit error rate performances are investigated on simple communication channel models. Observation of simulation results show that the ABSato algorithm provides better performance than the standard Sato algorithm on all the communication channel models.
    IEEE, English
    DOI:https://doi.org/10.1109/ICSPC.2007.4728606
    DOI ID:10.1109/ICSPC.2007.4728606, Web of Science ID:WOS:000266406700367
  • Image Denoising for Poisson Noise by Pixel Values Based Division and Wavelet Shrinkage               
    Eda S; Shimamura T
    Proceedings of International Symposium on Nonlinear Theory and Its Applications, First page:441, Last page:444, 2007
  • Equalization with Amplitude Banded LMS Adaptation for Stationary Channels               
    Shimamura T
    Proceedings of IASTED International Conference on Signal and Image Processing, First page:576, Last page:205, 2007
  • Performance of the Amplitude Banded LMS Equalizer on Stationary Channels               
    Shimamura T
    Proceedings of IEEE International Workshop on Nonlinear Dynamics of Electronic Systems, First page:289, Last page:292, 2007
  • Adaptive Non-Linear Prediction with Order Statistics for Speech in Impulsive Noise               
    Tanaka H; Ohhashi Y; Shimamura T
    Proceedings on WSEAS International Conference on Circuits, Systems, Signal and Telecommunications, First page:125, Last page:129, 2007
  • Discrete Cosine Transform Domain Parallel LMS Equalizer               
    Mohammed H.W; Shimamura T
    Proceedings on WSEAS International Conference on Circuits, Systems, Signal and Telecommunications, First page:119, Last page:124, 2007
  • 癒し音楽における1/fゆらぎと高周波成分との関連性               
    島村徹也; 小花あゆみ
    音楽音響研究会資料, Volume:26, First page:25, Last page:30, 2007
  • 音声信号の非線形予測と信号表現に関する研究               
    島村徹也
    総合研究機構研究プロジェクト研究成果報告書, Volume:5 (18年度), First page:602, Last page:603, 2007
  • 効率的な時間遅延推定のための間接的差分関数法               
    中村尚之; 島村徹也
    信号処理シンポジウム講演論文集, First page:401, Last page:405, 2007
  • 可変ステップサイズ正規化LMSアルゴリズムの一提案               
    竹川英樹; 島村徹也
    信号処理シンポジウム講演論文集, First page:466, Last page:471, 2007
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    Proceedings of NICOGRAPH, 2007
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    International Journal of Asia Digital Art and Design, Volume:6, First page:11, Last page:18, 2007
  • Magnitude Spectral Subtraction with DFTLMS Algorithm for Adaptive Line Enhancer               
    Tiengwattanatum C; Mohammed H.W; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:213, Last page:216, 2007
  • Performance of Adaptive Nonlinear Predictor with Order Statistics in Impulsive Noise               
    Tanaka H; Ohhashi Y; Shimamura T
    WSEAS Transactions on Signal Processing, Volume:2, 2007
  • Quality Improvement of Bone-Conducted Speech Using Linear Prediction Analysis Filter               
    Sugiyama T; Shimamura T; Yashima H
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:291, Last page:294, 2007
  • Linear Prediction Using Refined Autocorrelation Function               
    M. Shahidur Rahman; Tetsuya Shimamura
    EURASIP JOURNAL ON AUDIO SPEECH AND MUSIC PROCESSING, Volume:2007, First page:Article ID 45962, 9 Pages, 2007
    This paper proposes a new technique for improving the performance of linear prediction analysis by utilizing a refined version of the autocorrelation function. Problems in analyzing voiced speech using linear prediction occur often due to the harmonic structure of the excitation source, which causes the autocorrelation function to be an aliased version of that of the vocal tract impulse response. To estimate the vocal tract characteristics accurately, however, the effect of aliasing must be eliminated. In this paper, we employ homomorphic deconvolution technique in the autocorrelation domain to eliminate the aliasing effect occurred due to periodicity. The resulted autocorrelation function of the vocal tract impulse response is found to produce significant improvement in estimating formant frequencies. The accuracy of formant estimation is verified on synthetic vowels for a wide range of pitch frequencies typical for male and female speakers. The validity of the proposed method is also illustrated by inspecting the spectral envelopes of natural speech spoken by high-pitched female speaker. The synthesis filter obtained by the current method is guaranteed to be stable, which makes the method superior to many of its alternatives. Copyright (C) 2007 M. S. Rahman and T. Shimamura.
    SPRINGER INTERNATIONAL PUBLISHING AG, English
    DOI:https://doi.org/10.1155/2007/45962
    DOI ID:10.1155/2007/45962, ISSN:1687-4722, Web of Science ID:WOS:000207767400001
  • Indirect Cross-Correlation Method for Time Delay Estimation               
    Nakamura N; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:74, Last page:77, 2007
  • Complementary and Phase Banded LMS Equalizers for Rapidly Time-Varying Channels               
    Mohammed H.W; Shimamura T
    Journal of Signal Processing, Volume:11, First page:51, Last page:60, 2007
  • A Parallel Equalizer with LMS Adaptation in Discrete Cosine Transform Domain               
    Mohammed H.W; Shimamura T
    WSEAS Transactions on Signal Processing, Volume:2, 2007
  • Restoration of Bone-Conducted Speech with the Wiener Filter and Long-Term Spectra               
    Kamata K; Yamashita K; Shimamura T; Furukawa T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:583, Last page:586, 2007
  • Bone-Conducted Speech for Speaker Verification               
    Iijima S; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:172, Last page:175, 2007
  • Adaptive non-linear prediction for speech signals in mixture noise environments               
    Hirobumi Tanaka; Yuichiroh Ohhashi; Tetsuya Shimamura
    2006 International Symposium on Intelligent Signal Processing and Communications, ISPACS'06, First page:295, Last page:298, 2007
    For robust prediction analysis for speech signals in impulsive noise environments, we had proposed the OSLMS with AS predictor in [1]. Assuming general noise environments, however, we can not neglect background noises. Therefore, in this paper, we studied properties of the LPC in a mixture noise environment which has a content of impulsive noises and white Gaussian noises, and prove that an adaptive predictor perform more effectively in the mixture noises which has white noises with low power than batch predictors. Furthermore, we conducted prediction experiments using 3 adaptive predictors including the OSLMS with AS in the mixture noise environments. As a result, the OSLMS with AS predictor provided good performance in mixture noise environments which has practical white noise power, too. © 2006 IEEE.
    English
    DOI:https://doi.org/10.1109/ISPACS.2006.364890
    DOI ID:10.1109/ISPACS.2006.364890, SCOPUS ID:45249095876
  • A Parallel Estimator with LMS and RLS Adaptation for Fast Fading Channels               
    Oikawa S; Tsuda Y; Shimamura T
    First page:845, Last page:848, 2006
    DOI:https://doi.org/10.1109/ISPACS.2006.364777
    DOI ID:10.1109/ISPACS.2006.364777
  • Active Noise Control Using A Refined Filtering Approach               
    Isozaki K; Tsuda Y; Shimamura T
    2006
  • Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    First page:128, Last page:129, 2006
  • Learning for Bone-Conducted Speech via Adaptive and Neural Filters               
    Shimamura T; Tamiya T
    2006
  • A Harsh Noise Assessment Measure for Speech Enhancement               
    Yamashita K; Shimamura T
    2006
  • Improving Bone-Conducted Speech Quality via Neural Network               
    Shimamura T; Mamiya J; Tamiya T
    First page:628, Last page:632, 2006
    DOI:https://doi.org/10.1109/ISSPIT.2006.270876
    DOI ID:10.1109/ISSPIT.2006.270876
  • Speech Analysis Based on Modeling the Effective Voice Source(Speech Analysis, Statistical Modeling for Speech Processing)               
    島村徹也
    Volume:E89-D, Number:3, First page:1107, Last page:1115, 2006
    DOI:https://doi.org/10.1093/ietisy/e89-d.3.1107
    DOI ID:10.1093/ietisy/e89-d.3.1107, ISSN:0916-8532, CiNii Articles ID:110004719387
  • A Study on Normalized LMS Algorithm Using Refined Filtering Technique               
    Tsuda Y; Shimamura T
    First page:264, Last page:267, 2006
  • 高性能アクティブノイズキャンセルマイクロフォン開発におけるリアルタイムなディジタル雑音除去の研究               
    島村徹也; 和田存功
    Volume:7, First page:64, Last page:64, 2006
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    Yamashita T; Shimamura T
    Volume:10, First page:275, Last page:278, 2006
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    Yamashita K; Shimamura T
    2006
  • Refined Filtering for Normalized LMS Algorithm               
    Tsuda Y; Shimamura T
    Volume:2, First page:261, Last page:264, 2006
  • A Refined Filtering Approach to Adaptive Line Enhancement               
    Tsuda Y; Shimamura T
    First page:141, Last page:146, 2006
  • Autoregressive Moving Average (ARMA) Analysis of Speech by Modeling the Active Voice Source               
    Rahman M.S; Tanaka H; Shimamura T
    2006
  • Adaptive Time Variant Channel Equalization Using Phase Banded LMS Algorithm               
    Mohammed H.W; Shimamura T
    Volume:10, First page:227, Last page:230, 2006
  • Adaptive Time-Variant Channel Equalization Using Phase-Banded LMS Algorithm               
    Mohammed H. W; Shimamura T
    2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    Isozaki K; Tsuda Y; Shimamura T
    Volume:10, First page:279, Last page:282, 2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    Isozaki K; Tsuda Y; Shimamura T
    2006
  • A Parallel Estimator with LMS and RLS Adaptation for Fast Fading Channels               
    Oikawa S; Tsuda Y; Shimamura T
    Proceedings of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, First page:845, Last page:848, 2006
    DOI:https://doi.org/10.1109/ISPACS.2006.364777
    DOI ID:10.1109/ISPACS.2006.364777
  • Active Noise Control Using A Refined Filtering Approach               
    Isozaki K; Tsuda Y; Shimamura T
    Proceedings of the 35th International Congress and Exposition on Noise Control Engineering, 2006
  • Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Xin W; Kondo K; Tateno K; Konma T; Shimamura T
    Proceedings on Asia Digital Art and Design Association, First page:128, Last page:129, 2006
  • Learning for Bone-Conducted Speech via Adaptive and Neural Filters               
    Shimamura T; Tamiya T
    Proceedings of International Conference on Signals and Electronic Systems, 2006
  • A Harsh Noise Assessment Measure for Speech Enhancement               
    Yamashita K; Shimamura T
    Proceedings of European Conference on Signal Processing, 2006
  • Improving Bone-Conducted Speech Quality via Neural Network               
    Shimamura T; Mamiya J; Tamiya T
    Proceedings of IEEE International Symposium on Signal Processing and Information Technology, First page:628, Last page:632, 2006
    DOI:https://doi.org/10.1109/ISSPIT.2006.270876
    DOI ID:10.1109/ISSPIT.2006.270876
  • Speech Analysis Based on Modeling the Effective Voice Source(Speech Analysis, Statistical Modeling for Speech Processing)               
    島村徹也
    IEICE transactions on information and systems, Volume:E89-D, Number:3, First page:1107, Last page:1115, 2006
    DOI:https://doi.org/10.1093/ietisy/e89-d.3.1107
    DOI ID:10.1093/ietisy/e89-d.3.1107, ISSN:0916-8532, CiNii Articles ID:110004719387
  • A Study on Normalized LMS Algorithm Using Refined Filtering Technique               
    Tsuda Y; Shimamura T
    Proceedings of 5th WSEAS International Conference on Signal Processing, Robotics and Automation, First page:264, Last page:267, 2006
  • Coefficients - Delay simultaneous adaptation scheme for linear equalization of nonminimum phase channels               
    Y Tsuda; J Gamba; T Shimamura
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E89A, Number:1, First page:248, Last page:259, Jan. 2006
    An efficient adaptation technique of the delay is introduced for accomplishing more accurate adaptive linear equalization of nonminimum phase channels. It is focused that the filter structure and adaptation procedure of the adaptive Butler-Cantoni (ABC) equalizer is very suitable to deal with a variable delay for each iteration, compared with a classical adaptive linear transversal equalizer (LTE). We derive a cost function by comparing the system mismatch of an optimum equalizer coefficient vector with an equalizer coefficient vector with several delay settings. The cost function is square of difference of absolute values of the first element and the last element for the equalizer coefficient vector. The delay adaptation method based on the cost function is developed, which is involved with the ABC equalizer. The delay is adapted by checking the first and last elements of the equalizer coefficient vector and this results in an LTE providing a lower mean square error level than the other LTEs with the same order. We confirm the performance of the ABC equalizer with the delay adaptation method through computer simulations.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English
    DOI:https://doi.org/10.1093/ietfec/e89-a.1.248
    DOI ID:10.1093/ietfec/e89-a.1.248, ISSN:0916-8508, eISSN:1745-1337, CiNii Articles ID:110003486133, Web of Science ID:WOS:000234948500035
  • 高性能アクティブノイズキャンセルマイクロフォン開発におけるリアルタイムなディジタル雑音除去の研究
    島村徹也; 和田存功
    埼玉大学地域共同研究センター紀要, Volume:7, First page:64, Last page:64, 2006
    A spectral subtraction technique is carried out in which noise is estimated for non-speech duration and the estimated noise spectrum is subtracted from the noisy speech spectrum for speech duration.
    Japanese
    ISSN:1347-4758, CiNii Articles ID:120001371317
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    Yamashita T; Shimamura T
    Journal of Signal Processing, Volume:10, First page:275, Last page:278, 2006
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    Yamashita K; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Refined Filtering for Normalized LMS Algorithm               
    Tsuda Y; Shimamura T
    WSEAS Transactions on Signal Processing, Volume:2, First page:261, Last page:264, 2006
  • A Refined Filtering Approach to Adaptive Line Enhancement               
    Tsuda Y; Shimamura T
    回路とシステム軽井沢ワークショップ講演論文集, First page:141, Last page:146, 2006
  • Pitch Determination Using Aligned AMDF               
    M. Shahidur Rahman; Hirobumi Tanaka; Tetsuya Shimamura
    INTERSPEECH 2006 AND 9TH INTERNATIONAL CONFERENCE ON SPOKEN LANGUAGE PROCESSING, VOLS 1-5, First page:1714, Last page:1717, 2006
    A pitch determination method based on AMDF (Average Magnitude Difference Function) is proposed in this paper. The AMDF is often used to determine the pitch parameter in real-time speech processing applications. Failing trend of AMDF at higher lags, however, makes the method vulnerable to octave errors (pitch doubling or halving). In this paper, we propose an alignment technique that effectively eliminates the falling trend by aligning the AMDF peaks along a straight line. Experimental results on speech signals spoken by male and female speakers show that the current method can reduce the occurrence of octave errors in greater numbers when compared with other AMDF based functions.
    ISCA-INST SPEECH COMMUNICATION ASSOC, English
    Web of Science ID:WOS:000269965901166
  • Autoregressive Moving Average (ARMA) Analysis of Speech by Modeling the Active Voice Source               
    Rahman M.S; Tanaka H; Shimamura T
    Proceedings of International Conference on Signals and Electronic Systems, 2006
  • Adaptive Time Variant Channel Equalization Using Phase Banded LMS Algorithm               
    Mohammed H.W; Shimamura T
    Journal of Signal Processing, Volume:10, First page:227, Last page:230, 2006
  • Adaptive Time-Variant Channel Equalization Using Phase-Banded LMS Algorithm               
    Mohammed H. W; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    Isozaki K; Tsuda Y; Shimamura T
    Journal of Signal Processing, Volume:10, First page:279, Last page:282, 2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    Isozaki K; Tsuda Y; Shimamura T
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Time delay interpolation by system response coefficient ratios               
    J Gamba; T Shimamura
    IEEE SIGNAL PROCESSING LETTERS, Volume:12, Number:9, First page:641, Last page:644, Sep. 2005
    In this letter, we propose a new method of time delay interpolation based on the finite impulse response (FIR) filter coefficient ratios and derived from the Lagrange interpolation coefficients. The proposed method gives an explicit formula for the time delay that requires no frequency-domain transformations, making it suitable for entirely time-domain applications. Simulation results confirm the effectiveness of the proposed method.
    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, English
    DOI:https://doi.org/10.1109/LSP.2005.853047
    DOI ID:10.1109/LSP.2005.853047, ISSN:1070-9908, eISSN:1558-2361, Web of Science ID:WOS:000231234600012
  • Nonstationary noise estimation using low-frequency regions for spectral subtraction               
    K Yamashita; T Shimamura
    IEEE SIGNAL PROCESSING LETTERS, Volume:12, Number:6, First page:465, Last page:468, Jun. 2005
    In this letter, a noise estimation method for spectral subtraction is proposed by using low-frequency regions of noisy speech. The method allows tracking the time variation of noise without complicated computation. The performance of a spectral subtraction method based on the new noise estimation is investigated, and its effectiveness is shown. in practical experiments.
    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, English
    DOI:https://doi.org/10.1109/LSP.2005.847864
    DOI ID:10.1109/LSP.2005.847864, ISSN:1070-9908, Web of Science ID:WOS:000229157700009
  • Equalizer-aided time delay tracking based on L-1-normed finite differences               
    J Gamba; T Shimamura
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E88A, Number:4, First page:978, Last page:987, Apr. 2005
    This paper addresses the estimation of time delay between two spatially separated noisy signals by system identification modeling with the input and output corrupted by additive white Gaussian noise. The proposed method is based on a modified adaptive Butler-Cantoni equalizer that decouples noise variance estimation from channel estimation. The bias in time delay estimates that is induced by input noise is reduced by an IIR whitening filter whose coefficients are found by the Burg algorithm. For step time-variant delays, a dual mode operation scheme is adopted in which we define a normal operating (tracking) mode and an interrupt operating (optimization) mode. In the tracking mode, only a few coefficients of the impulse response vector are monitored through L-1-normed finite forward differences tracking, while in the optimization mode, the time delay optimized. Simulation results confirm the superiority of the proposed approach at low signal-to-noise ratios.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English
    DOI:https://doi.org/10.1093/ietfec/e88-a.4.978
    DOI ID:10.1093/ietfec/e88-a.4.978, ISSN:0916-8508, eISSN:1745-1337, CiNii Articles ID:10016562650, Web of Science ID:WOS:000228412600025
  • Spectrum estimation by noise-compensated data extrapolation               
    J Gamba; T Shimamura
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E88A, Number:3, First page:702, Last page:711, Mar. 2005
    High-resolution spectrum estimation techniques have been extensively studied in recent publications. Knowledge of the noise variance is vital for spectrum estimation from noise-corrupted observations. This paper presents the use of noise compensation and data extrapolation for spectrum estimation. We assume that the observed data sequence can be represented by a set of autoregressive parameters. A recently proposed iterative algorithm is then used for noise variance estimation while autoregressive parameters are used for data extrapolation. We also present analytical results to show the exponential decay characteristics of the extrapolated samples and the frequency domain smoothing effect of data extrapolation. Some statistical results are also derived. The proposed noise-compensated data extrapolation approach is applied to both the autoregressive and FFT-based spectrum estimation methods. Finally, simulation results show the superiority of the method in terms of bias reduction and resolution improvement for sinusoids buried in noise.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English
    DOI:https://doi.org/10.1093/ietfec/e88-a.3.702
    DOI ID:10.1093/ietfec/e88-a.3.702, ISSN:0916-8508, eISSN:1745-1337, CiNii Articles ID:110003213364, Web of Science ID:WOS:000227828700012
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    Shimamura T; Yamauchi J
    First page:47, Last page:52, 2005
  • Improved Spectral Subtraction Utilizing Iterative Processing               
    YAMASHITA K.; OGATA Shin'ya; SHIMAMURA Tetsuya
    The IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (Japanese edition) A, Volume:J88-A, Number:11, First page:1246, Last page:1257, 2005
    copyright(c)2005 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html本論文では, 雑音付加音声の雑音低減の手法であるスペクトル引き算法に, 反復処理とそれに適したパラメータ設定を施した, 新しい雑音抑制技術を提案する. 反復処理とは, 一度雑音低減処理を施した推定音声を再度入力信号とみなし, 音声強調処理を施す手段であり, 残留雑音の低減が見込まれる. 反復ごとにパラメータを調整することで, 音声の劣化を抑えた更なる残留雑音低減が可能となる. また, 提案法を実行する際に, スペクトル引き算のもつリアルタイム性を保持する手法も同時に提案する. 2種類の提案法の特性を, 白色雑音, 自動車雑音, 人混み雑音を付加した実音声を用い, 従来のスペクトル引き算法及びその改良法と比較する. 主観評価及び客観評価により, 各提案法はすべての雑音環境に対して優れた結果を示すことが確認された.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003501908, CiNii Books ID:AN10013345
  • Restoration from Image Degraded by White Noise Based on Iterative Spectral Subtraction Method               
    Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    First page:6288, Last page:6291, 2005
    DOI:https://doi.org/10.1109/ISCAS.2005.1466073
    DOI ID:10.1109/ISCAS.2005.1466073
  • Sinusoidal Time Delay Tracking by a Self-tuned LMS Filter with Interpolation Based on System Response Coefficient Ratios               
    Gamba J; Shimamura T
    First page:6, Last page:9, 2005
  • SIDOモデルを用いたブラインド等化に関する一検討               
    藤田昌宏; 津田雄亮; 島村徹也
    Volume:104719, First page:37, Last page:41, 2005
  • 音声信号のための雑音低減技術 (その2)               
    島村徹也
    Volume:9, Number:3, First page:183, Last page:188, 2005
  • 音声信号のための雑音低減技術 (その1)               
    島村徹也
    Volume:9, Number:2, First page:91, Last page:98, 2005
  • 高性能アクティブノイズキャンセルヘッドフォン開発におけるリアルタイムなディジタル雑音除去の研究               
    島村徹也; 和田存功
    Volume:6, First page:64, Last page:66, 2005
  • 反復アルゴリズムを用いたスペクトル引き算法による音声強調               
    緒方伸哉; 島村徹也
    Volume:9, Number:3, First page:255, Last page:266, 2005
    Japanese
    ISSN:1342-6230, CiNii Articles ID:40006817548, CiNii Books ID:AA11147833
  • 音声強調のための反射係数を利用した雑音パワー推定               
    緒方伸哉; 島村徹也
    Volume:9, First page:325, Last page:334, 2005
  • 洗練フィルタリングを用いたアクティブノイズコントロールシステム               
    磯崎弘太; 津田雄介; 島村徹也
    Volume:105, Number:482, First page:45, Last page:50, 2005
  • Equalization of Time Variant Multipath Channels Using Channel Estimation Based Classification Techniques               
    Tsutsumi Y; Tsuda Y; Shimamura T
    First page:2D-09.3, 2005
  • Channel Estimation Based on Classification Approaches to Equalization of Time Variant Multipath Channels               
    Tsutsumi Y; Tsuda Y; Shimamura T
    Volume:105, Number:29, First page:47, Last page:52, 2005
  • Performance Improvement of a Channel Estimation Based Equalizer on Time Variant Multipath Channels               
    Tsuda Y; Shimamura T
    First page:A4-2, 2005
  • Adaptive Nonlinear Predictive Analysis for Speech Using a Cascaded LMS-VSLMS Predictor               
    Tanaka H; Shimamura T
    First page:404, Last page:409, 2005
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    Shimamura T; Yamauchi J
    Volume:3, First page:323, Last page:330, 2005
  • Variable Step-Size LMS Estimator for Fast Fading Channels               
    OIKAWA Shingo; TSUDA Yusuke; SHIMAMURA Tetsuya
    IEICE technical report. Image engineering, Volume:105, Number:30, First page:53, Last page:58, 2005
    We propose a novel channel estimation technique for fast fading channels. The proposed scheme supposes multiple linear transversal filters, which are constructed in a parallel structure. The estimator coefficients for the proposed estimation scheme are adapted by the least mean square (LMS) algorithm. To obtain a further performance improvement of the proposed scheme, a technique to adjust the step-size for the LMS is also introduced. Computer simulation results show that the proposed method provides a significant improvement related to the conventional LMS estimator in high fade rate conditions.
    The Institute of Electronics, Information and Communication Engineers, English
    ISSN:0913-5685, CiNii Articles ID:110003205481, CiNii Books ID:AN10013006
  • A Parallel Estimator with LMS Adaptation for Fast Fading Channels               
    Oikawa S; Tsuda Y; Shimamura T
    First page:2C-12.4, 2005
  • Frequency Domain Magnitude Banded LMS Algorithm for Equalization of Rapidly Time Variant Channels               
    Mohammed H,W; Shimamura T; Cowan C.F.N
    Volume:12, First page:1, Last page:6, 2005
  • White Noise Removal in Image by Iterative Spectral Subtraction Method               
    Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    First page:13, Last page:16, 2005
  • Noise Removal for Image Degraded by Poisson Noise: A Pixel Values Based Division Approach               
    Kawanaka R; Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    First page:5, Last page:8, 2005
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    Shimamura T; Yamauchi J
    Proceedings of WSEAS International Conference on Electronics, Control and Signal Processing, First page:47, Last page:52, 2005
  • 反復処理を利用した改良スペクトル引き算(音声, <小特集>スマート信号処理とその画像・音声処理への応用論文)               
    山下浩平; 緒方伸哉; 島村徹也
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J88-A, Number:11, First page:1246, Last page:1257, 2005
    copyright(c)2005 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html本論文では, 雑音付加音声の雑音低減の手法であるスペクトル引き算法に, 反復処理とそれに適したパラメータ設定を施した, 新しい雑音抑制技術を提案する. 反復処理とは, 一度雑音低減処理を施した推定音声を再度入力信号とみなし, 音声強調処理を施す手段であり, 残留雑音の低減が見込まれる. 反復ごとにパラメータを調整することで, 音声の劣化を抑えた更なる残留雑音低減が可能となる. また, 提案法を実行する際に, スペクトル引き算のもつリアルタイム性を保持する手法も同時に提案する. 2種類の提案法の特性を, 白色雑音, 自動車雑音, 人混み雑音を付加した実音声を用い, 従来のスペクトル引き算法及びその改良法と比較する. 主観評価及び客観評価により, 各提案法はすべての雑音環境に対して優れた結果を示すことが確認された.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003501908, CiNii Books ID:AN10013345
  • Speech enhancement using a technique of adaptive bias suppression               
    Hirobumi Tanaka; Naomi Yamamura; Yuichiroh Ohhashi; Tetsuya Shimamura
    2005 39TH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS, VOLS 1 AND 2, First page:540, Last page:544, 2005
    In this paper, we assume speech corrupted by white Gaussian noise and propose a technique of adaptive bias suppression. A linear predictor is used as the basic filter and gamma-NLMS(Normalized Least Mean Square) algorithm, which is useful for suppressing bias, is adopted for the predictor adaptation. In addition, for suppressing bias more effectively we apply a weighting parameter and filter banks to the predictor. Experiments on continuous speech result in that the proposed predictor provides superior performances.
    IEEE, English
    Web of Science ID:WOS:000238142000103
  • Voice source modeling for accurate speech analysis               
    M. Shahidur Rahman; Tetsuya Shimamura
    2005 39TH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS, VOLS 1 AND 2, First page:305, Last page:309, 2005
    A two-pass least square method have been proposed for estimating the vocal tract parameters. An often encountered problem in using the conventional linear prediction analysis is due to the harmonic structure of the excitation source of voiced speech. This harmonic characteristic is coupled with the estimation of autoregressive (AR) coefficients that results in difficulties in estimating the vocal tract filter. This paper models the effective voice source from the residual obtained through the covariance analysis in the first-pass which is then used as input to the second-pass least square analysis. A better source-filter separation is thus achieved. The formant frequencies and bandwidths estimated using the proposed method for synthetic vowels are found to be accurate up to a factor of more than three (in percent) compared to the conventional method. Since the source characteristic is taken into account, local variations due to the positioning of analysis window are reduced significantly. The validity of the proposed method is also verified by inspecting the spectra obtained from natural vowel sounds uttered by high-pitched female speaker.
    IEEE, English
    Web of Science ID:WOS:000238142000057
  • Quality improvement of bone-conducted speech               
    Tetsuya Shimamura; Takeshi Tomikura
    Proceedings of the 2005 European Conference on Circuit Theory and Design, Volume:3, First page:73, Last page:76, 2005
    One method to communicate in a very high noise environment is to use bone-conducted speech. In this paper, a technique of improving the quality of bone-conducted speech is presented. The bone-conducted speech signal of a speaker is passed through a reconstruction filter designed by using the long-term spectra of the bone-conducted and normal speech signals. Properties of the normal, bone-conducted and reconstructed speech signals are investigated and it is shown that for speaker recognition, the reconstructed speech signal could be usefully utilized.
    English
    DOI:https://doi.org/10.1109/ECCTD.2005.1523063
    DOI ID:10.1109/ECCTD.2005.1523063, SCOPUS ID:33749024465
  • A reconstruction filter for bone-conducted speech               
    Tetsuya Shimamura; Toshiki Tamiya
    Midwest Symposium on Circuits and Systems, Volume:2005, First page:1847, Last page:1850, 2005
    Bone conduction is useful as a tool to accomplish speech enhancement in noisy environments. In this paper, we design a linear phase impulse response filter to reconstruct the quality of the bone-conducted speech signal obtained from a speaker. The bone-conducted speech observation as well as the normal speech information are effectively utilized to design the filter. From experimental results, the properties of the reconstruction filter are investigated. © 2005 IEEE.
    English
    DOI:https://doi.org/10.1109/MWSCAS.2005.1594483
    DOI ID:10.1109/MWSCAS.2005.1594483, ISSN:1548-3746, SCOPUS ID:33847106970
  • Restoration from Image Degraded by White Noise Based on Iterative Spectral Subtraction Method               
    Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    Proceedings of IEEE International Symposium on Circuits and Systems, First page:6288, Last page:6291, 2005
    DOI:https://doi.org/10.1109/ISCAS.2005.1466073
    DOI ID:10.1109/ISCAS.2005.1466073
  • Linear prediction using homomorphic deconvolution in the autocorrelation domain               
    MS Rahman; T Shimamura
    2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS, First page:2855, Last page:2858, 2005
    The conventional model of the linear prediction analysis suffers from difficulties in estimating vocal tract characteristics of high-pitched speakers. This paper shows that for voiced speech the vocal tract characteristics can be estimated accurately by homomorphic deconvolution in the autocorrelation domain. The speech autocorrelation function used by linear prediction is actually an 'aliased' version of that of the vocal tract system impulse response. This aliasing occurs due to the periodic nature of voiced speech. By using cepstrum analysis, the effect of this periodicity is eliminated from the autocorrelation function which is also periodic with the same periodicity as speech itself. The formant frequencies estimated using the deconvolved autocorrelation sequences of the system impulse response are found to be accurate by more than an order of magnitude when compared with the conventional linear prediction. The accuracy of formant estimation is verified on synthetic vowels for a wide range of pitch periods. The validity of the proposed method is also examined by inspecting the estimated spectral envelopes of real speech spoken by a female child.
    IEEE, English
    DOI:https://doi.org/10.1109/ISCAS.2005.1465222
    DOI ID:10.1109/ISCAS.2005.1465222, ISSN:0271-4302, Web of Science ID:WOS:000232002402237
  • Sinusoidal Time Delay Tracking by a Self-tuned LMS Filter with Interpolation Based on System Response Coefficient Ratios               
    Gamba J; Shimamura T
    Proceedings of IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing, First page:6, Last page:9, 2005
  • SIDOモデルを用いたブラインド等化に関する一検討               
    藤田昌宏; 津田雄亮; 島村徹也
    電子情報通信学会技術研究報告, Volume:104719, First page:37, Last page:41, 2005
  • 音声信号のための雑音低減技術 (その2)               
    島村徹也
    Journal of Signal Processing, Volume:9, Number:3, First page:183, Last page:188, 2005
    Japanese
    ISSN:1342-6230, CiNii Articles ID:40006817541, CiNii Books ID:AA11147833
  • 音声信号のための雑音低減技術 (その1)               
    島村徹也
    Journal of Signal Processing, Volume:9, Number:2, First page:91, Last page:98, 2005
  • 高性能アクティブノイズキャンセルヘッドフォン開発におけるリアルタイムなディジタル雑音除去の研究               
    島村徹也; 和田存功
    埼玉大学地域共同研究センター紀要, Volume:6, Number:6, First page:64, Last page:66, 2005
    For the purpose of developing an active noise canceling headphone, techniques of noise reduction are investigated from the viewpoints of digital as well as analogue processing. A prediction based digital method is derived and it is shown that the proposed technique is very useful for noise canceling.
    Japanese
    ISSN:1347-4758, CiNii Articles ID:120001371339, CiNii Books ID:AA11808968
  • 反復アルゴリズムを用いたスペクトル引き算法による音声強調               
    緒方伸哉; 島村徹也
    信号処理, Volume:9, Number:3, First page:255, Last page:266, 2005
    Japanese
    ISSN:1342-6230, CiNii Articles ID:40006817548, CiNii Books ID:AA11147833
  • 音声強調のための反射係数を利用した雑音パワー推定               
    緒方伸哉; 島村徹也
    信号処理, Volume:9, Number:4, First page:325, Last page:334, 2005
    Japanese
    ISSN:1342-6230, CiNii Articles ID:40006886206, CiNii Books ID:AA11147833
  • 洗練フィルタリングを用いたアクティブノイズコントロールシステム               
    磯崎弘太; 津田雄介; 島村徹也
    電子情報通信学会技術研究報告, Volume:105, Number:482, First page:45, Last page:50, 2005
  • Equalization of Time Variant Multipath Channels Using Channel Estimation Based Classification Techniques               
    Tsutsumi Y; Tsuda Y; Shimamura T
    Proceedings of IEEE Region 10 International Conference on Electrical and Electronic Technology, First page:2D-09.3, 2005
  • Channel Estimation Based on Classification Approaches to Equalization of Time Variant Multipath Channels               
    Tsutsumi Y; Tsuda Y; Shimamura T
    Technical Report of the IEICE, Volume:105, Number:29, First page:47, Last page:52, 2005
  • Performance Improvement of a Channel Estimation Based Equalizer on Time Variant Multipath Channels               
    Tsuda Y; Shimamura T
    Proceedings of Signal Processing Symposium, First page:A4-2, 2005
  • Adaptive Nonlinear Predictive Analysis for Speech Using a Cascaded LMS-VSLMS Predictor               
    Tanaka H; Shimamura T
    Proceedings of IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing, First page:404, Last page:409, 2005
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    Shimamura T; Yamauchi J
    WSEAS Transactions on Signal Processing, Volume:3, First page:323, Last page:330, 2005
  • Formant frequency estimation of high-pitched speech by homomorphic prediction               
    M. Shahidur Rahman; Tetsuya Shimamura
    Acoustical Science and Technology, Volume:26, Number:6, First page:502, Last page:510, 2005
    The conventional model of the linear prediction analysis suffers from difficulties in estimating vocal tract characteristics of high-pitched speakers. This is because the autocorrelation function used by the autocorrelation method of linear prediction for estimating autoregressive coefficients is actually an "aliased" version of that of the vocal tract impulse response. This "aliasing" occurs due to the periodic nature of voiced speech. Generally it is accepted that homomorphic filtering can be used to obtain an estimate of vocal tract impulse response which is free from periodicity. Thus linear prediction of the resulting vocal tract impulse response (referred to as homomorphic prediction) is expected to be free from variations of fundamental frequencies. To our knowledge any experimental study, however, has not yet appeared on the suitability of this method for analyzing high-pitched speech. This paper presents a detail study on the prospects of homomorphic prediction as a formant tracking tool especially for high-pitched speech where linear prediction fails to obtain accurate estimation. The formant frequencies estimated using the proposed method are found to be accurate by more than an order of magnitude compared to the conventional procedure. The accuracy of formant estimation is verified on synthetic vowels for a wide range of pitch periods covering typical male and high-pitched female speakers. The validity of the proposed method is also examined by inspecting the spectral envelopes of natural speech spoken by high-pitched female speakers. We noticed that almost all the previous methods dealing with this limitation of linear prediction are based on the covariance technique where the obtained AR filter can be unstable. The solutions obtained by the current method are guaranteed to be stable which makes it superior for many speech analysis applications.
    English
    DOI:https://doi.org/10.1250/ast.26.502
    DOI ID:10.1250/ast.26.502, ISSN:1346-3969, CiNii Articles ID:110003143601, SCOPUS ID:27644474210
  • Variable Step-Size LMS Estimator for Fast Fading Channels               
    Oikawa S; Tsuda Y; Shimamura T
    Technical Report of the IEICE, Volume:105, Number:30, First page:53, Last page:58, 2005
    We propose a novel channel estimation technique for fast fading channels. The proposed scheme supposes multiple linear transversal filters, which are constructed in a parallel structure. The estimator coefficients for the proposed estimation scheme are adapted by the least mean square (LMS) algorithm. To obtain a further performance improvement of the proposed scheme, a technique to adjust the step-size for the LMS is also introduced. Computer simulation results show that the proposed method provides a significant improvement related to the conventional LMS estimator in high fade rate conditions.
    The Institute of Electronics, Information and Communication Engineers, English
    ISSN:0913-5685, CiNii Articles ID:110003205481, CiNii Books ID:AN10013006
  • A Parallel Estimator with LMS Adaptation for Fast Fading Channels               
    Oikawa S; Tsuda Y; Shimamura T
    Proceedings of IEEE Region 10 International Conference on Electrical and Electronic Technology, First page:2C-12.4, 2005
  • Frequency Domain Magnitude Banded LMS Algorithm for Equalization of Rapidly Time Variant Channels               
    Mohammed H,W; Shimamura T; Cowan C.F.N
    WSEAS Transactions on Electronics, Volume:12, First page:1, Last page:6, 2005
  • White Noise Removal in Image by Iterative Spectral Subtraction Method               
    Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:13, Last page:16, 2005
  • Noise Removal for Image Degraded by Poisson Noise: A Pixel Values Based Division Approach               
    Kawanaka R; Kobayashi T; Shimamura T; Hosoya T; Takahashi Y
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, First page:5, Last page:8, 2005
  • 音声信号のための順序統計を用いた適応非線形予測器と反復法によるその特性改善               
    田中啓文; 早川晴子; 島村徹也
    Volume:J87-A, Number:7, First page:899, Last page:912, 2004
  • ピッチ同期加算処理を用いた雑音低減に基づくLPC分析               
    島村徹也; 黒岩世進伸
    Volume:J87, Number:A4, First page:458, Last page:469, 2004
  • A New Method of Noise Variance Estimation from Low-Order Yule-Walker Equations (Digital Signal Processing)               
    島村徹也
    Volume:E87-A, Number:1, First page:270, Last page:274, 2004
  • 非最小位相通信路における線形トランスバーサル等化器の特性改善 -係数および遅延量の同時適応-               
    津田雄亮; 島村徹也
    First page:B4-3, 2004
  • 反復スペクトル引き算法による雑音重畳画像からの復元               
    小林徹也; 島村徹也; 細谷徹夫; 高橋由武
    2004
  • Nonlinear Predictive Analysis of Speech by Iterative Approach               
    Tanaka H; Shimamura T
    First page:2055, Last page:2058, 2004
  • Reconstruction Filter design for Bone-Conducted Speech               
    Tamiya T; Shimamura T
    First page:1, Last page:4, 2004
  • Non-Stationary Noise Estimation Utilizing Harmonic Structure for Spectral Subtraction               
    Shimamura T; Yamauchi J
    First page:2305, Last page:2309, 2004
  • Noise-Robust Fundamental Frequency Extraction Method Based on Exponentiated Band-Limited Amplitude Spectrum               
    Shimamura T; Takagi H
    First page:II1 41-144, 2004
  • Pitch synchronous addition and extension for linear predictive analysis of noisy speech               
    T Shimamura
    NORSIG 2004: PROCEEDINGS OF THE 6TH NORDIC SIGNAL PROCESSING SYMPOSIUM, Volume:46, First page:196, Last page:199, 2004
    This paper proposes an approach for pitch synchronous linear predictive coding (LPC) of speech in noisy environments. A not. se reduction method is derived which produces an enhanced speech signal with one pitch period. For the proposed LPC method, the enhanced one pitch speech signal is used in a form of pitch extension so that the autocorrelation function is obtained accurately. Simulation experiments show that the proposed LPC method provides a superior performance in white noise.
    HELSINKI UNIVERSITY TECHNOLOGY, English
    ISSN:1458-6401, Web of Science ID:WOS:000225463400050
  • Adaptive Non-linear Prediction of Speech in Impulse Noise               
    Ohhashi Y; Tanaka H; Shimamura T
    First page:1675, Last page:1678, 2004
  • Improved model of SPAC (Speech Processing System by use of autocorrelation function) utilizing spectral subtraction as preprocessing               
    Ogata S; Ebata S; Shimamura T
    First page:3037, Last page:3040, 2004
  • A Novel Amplitude Banded RLS Algorithm for Equalization of Time Variant Multipath Channels               
    Mohammed H.W; Shimamura T
    First page:433, Last page:438, 2004
  • Equalizer-aided time delay tracking based on finite differences               
    J. Gamba; Y. Tsuda; T. Shimamura
    First page:B4-4, 2004
  • An adaptive Butler-Cantoni based time delay estimation (ABCTDE) method- IIR whitening filter approach               
    Gamba J; Tsuda Y; Shimamura T
    First page:265, Last page:268, 2004
  • 音声信号のための順序統計を用いた適応非線形予測器と反復法によるその特性改善               
    田中啓文; 早川晴子; 島村徹也
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J87-A, Number:7, First page:899, Last page:912, 2004
  • ピッチ同期加算処理を用いた雑音低減に基づくLPC分析               
    島村徹也; 黒岩世進伸
    電子情報通信学会論文誌, Volume:J87, Number:A4, First page:458, Last page:469, 2004
  • A New Method of Noise Variance Estimation from Low-Order Yule-Walker Equations (Digital Signal Processing)               
    島村徹也
    IEICE transactions on fundamentals of electronics, communications and computer sciences, Volume:E87-A, Number:1, First page:270, Last page:274, 2004
  • 非最小位相通信路における線形トランスバーサル等化器の特性改善 -係数および遅延量の同時適応-               
    津田雄亮; 島村徹也
    Proc. 第19回信号処理シンポジウム講演論文集, First page:B4-3, 2004
  • 反復スペクトル引き算法による雑音重畳画像からの復元               
    小林徹也; 島村徹也; 細谷徹夫; 高橋由武
    電子情報通信学会技術研究報告, 2004
  • Nonlinear Predictive Analysis of Speech by Iterative Approach               
    Tanaka H; Shimamura T
    Proc. 12th Europian Signal Processing Conf., First page:2055, Last page:2058, 2004
  • Reconstruction Filter design for Bone-Conducted Speech               
    Tamiya T; Shimamura T
    Proceedings of International Conference on Spoken Language Processing, First page:1, Last page:4, 2004
  • Non-Stationary Noise Estimation Utilizing Harmonic Structure for Spectral Subtraction               
    Shimamura T; Yamauchi J
    Proceedings of Asilomar Conference on Signals, Systems and Computers, First page:2305, Last page:2309, 2004
  • Noise-Robust Fundamental Frequency Extraction Method Based on Exponentiated Band-Limited Amplitude Spectrum               
    Shimamura T; Takagi H
    Proc. 47th IEEE International Midwest Symposium on Circuits and Systems, First page:II1 41-144, 2004
  • Pitch Synchronous Addition and Extension for Linear Predictive Analysis of Noisy Speech               
    Shimamura T; Kuroiwa Y
    Proc. 6th Nordic Signal Processing Symposium, First page:196, Last page:199, 2004
  • Adaptive Non-linear Prediction of Speech in Impulse Noise               
    Ohhashi Y; Tanaka H; Shimamura T
    Proc. 18th International Congress on Acoustics, First page:1675, Last page:1678, 2004
  • Improved model of SPAC (Speech Processing System by use of autocorrelation function) utilizing spectral subtraction as preprocessing               
    Ogata S; Ebata S; Shimamura T
    Proc. 18th International Congress on Acoustics, First page:3037, Last page:3040, 2004
  • A Novel Amplitude Banded RLS Algorithm for Equalization of Time Variant Multipath Channels               
    Mohammed H.W; Shimamura T
    Proceedings of IFAC Workshop on Adaptation and Learning in Control and Signal Processing, First page:433, Last page:438, 2004
  • Equalizer-aided time delay tracking based on finite differences               
    J. Gamba; Y. Tsuda; T. Shimamura
    Proc. 19th IEICE Signal Processing Symposium, First page:B4-4, 2004
  • An adaptive Butler-Cantoni based time delay estimation (ABCTDE) method- IIR whitening filter approach               
    Gamba J; Tsuda Y; Shimamura T
    Proceedings of IEEE International Symposium on Circuits and Systems, First page:265, Last page:268, 2004
  • 帯域制限をかけた振幅スペクトルのべき乗に基づく基本周波数抽出法(音声,聴覚)               
    島村徹也; 高木浩司
    Volume:J86-A, Number:11, First page:1097, Last page:1107, 2003
  • 帯域制限をかけた振幅スペクトルのべき乗に基づく基本周波数抽出法(音声,聴覚)               
    島村徹也; 高木浩司
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J86-A, Number:11, First page:1097, Last page:1107, 2003
  • Noise estimation using high frequency regions for spectral subtraction               
    J Yamauchi; T Shimamura
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E85A, Number:3, First page:723, Last page:727, Mar. 2002
    This paper presents an improved spectral subtraction method for speech enhancement. A new noise estimation method is derived in which the noise is assumed to be white. By using the property that a white noise spectrum is flat, high frequency components of a noisy speech spectrum arc, averaged and the standard deviation of the noise is estimated. This operation is performed in the analysis segment, thus the spectral subtraction method combined with the new noise estimation method does not need non-speech segments and as a result can adapt to non-stationary noise conditions. The effectiveness of the proposed spectral subtraction method is confirmed by experiments.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Report scientific journal
    ISSN:0916-8508, eISSN:1745-1337, Web of Science ID:WOS:000174258000021
  • Amplitude banded RLS approach to time variant channel equalization               
    T Shimamura; CFN Cowan
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E84A, Number:11, First page:2946, Last page:2949, Nov. 2001
    This paper proposes a non-linear adaptive algorithm, the amplitude banded RLS (ABRLS) algorithm, as an adaptation procedure for time variant channel equalizers. In the ABRLS algorithm, a coefficient matrix is updated based on the amplitude level of the received sequence. To enhance the capability of tracking for the ABRLS algorithm, a parallel adaptation scheme is utilized which involves the structures of decision feedback equalizer (DFE). Computer simulations demonstrate that the novel ABRLS based equalizer provides a significant improvement relative to the conventional RLS DFE on a rapidly time variant communication channel.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Report scientific journal
    ISSN:0916-8508, eISSN:1745-1337, Web of Science ID:WOS:000172132200044
  • Weighted autocorrelation for pitch extraction of noisy speech               
    T Shimamura; H Kobayashi
    IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING, Volume:9, Number:7, First page:727, Last page:730, Oct. 2001
    In this paper, we propose a modified version of the autocorrelation pitch extraction method well known to be robust against noise. Utilizing that the average magnitude difference function (AMDF) has similar characteristics with the autocorrelation function, the autocorrelation function is weighted by the reciprocal of the AMDF By simulation experiments, it is shown that the proposed pitch extraction method is useful in noisy environments.
    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, English
    DOI:https://doi.org/10.1109/89.952490
    DOI ID:10.1109/89.952490, ISSN:1063-6676, Web of Science ID:WOS:000171193600002
  • A fast converging RLS equaliser               
    T Shimamura
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E84A, Number:2, First page:675, Last page:680, Feb. 2001
    It is well known that based on the structure of a transversal filter, the RLS equaliser provides the fastest convergence in stationary environments. This paper addresses an adaptive transversal equaliser which has the potential to provide more faster convergence than the RLS equaliser. A comparison is made with respect to computational complexity required for each update of equaliser coefficients, and computer simulations are demonstrated to show the superiority of the proposed equaliser.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Report scientific journal
    ISSN:1745-1337, Web of Science ID:WOS:000166826000039
  • 線形予測分析に基づくホルマント周波数抽出の雑音耐性の改善               
    島村徹也; 趙奇方; 高橋淳一; 鈴木誠史
    Volume:J84-A, Number:6, First page:745, Last page:758, 2001
  • 平方根及び4乗根パワースペクトルの自己相関に基づくピッチ抽出(研究速報)               
    島村徹也; 吉尾重治; 趙奇方; 鈴木誠史
    Volume:J84-A, Number:3, First page:436, Last page:440, 2001
  • Equalisation of Time Variant Multipath Channels Using Amplitude Banded LMS Algorithms(Digital Signal Processing)(Regular Section)               
    島村徹也
    Volume:E84-A, Number:3, First page:802, Last page:812, 2001
  • IIR-Type Adaptive Equalizer with AR Prefilter and IIR-Type Wiener Filter               
    SHIMAMURA Tetsuya; SUZUKI Jouji
    The Transactions of the Institute of Electronics,Information and Communication Engineers. A, Volume:J84-A, Number:1, First page:109, Last page:112, 2001
    copyright(c)2001 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html筆者らは, 先にARプレフィルタを用いたIIR型の適応等化器を提案している.本論文では, そのIIR型適応等化器の特性を解析し, IIR型ウィーナーフィルタとの関係を明らかにする.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003313621, CiNii Books ID:AN10013345
  • 線形予測分析に基づくホルマント周波数抽出の雑音耐性の改善               
    島村徹也; 趙奇方; 高橋淳一; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J84-A, Number:6, First page:745, Last page:758, 2001
  • 平方根及び4乗根パワースペクトルの自己相関に基づくピッチ抽出(研究速報)               
    島村徹也; 吉尾重治; 趙奇方; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J84-A, Number:3, First page:436, Last page:440, 2001
  • Equalisation of Time Variant Multipath Channels Using Amplitude Banded LMS Algorithms(Digital Signal Processing)(Regular Section)               
    島村徹也
    IEICE transactions on fundamentals of electronics, communications and computer sciences, Volume:E84-A, Number:3, First page:802, Last page:812, 2001
  • A Fast Converging RLS Equaliser               
    島村徹也
    IEICE transactions on fundamentals of electronics, communications and computer sciences, Volume:E84-A, Number:2, First page:675, Last page:680, 2001
  • ARプレフィルタを用いたIIR型適応等化器とIIR型ウィーナーフィルタ               
    島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J84-A, Number:1, First page:109, Last page:112, 2001
    copyright(c)2001 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html筆者らは, 先にARプレフィルタを用いたIIR型の適応等化器を提案している.本論文では, そのIIR型適応等化器の特性を解析し, IIR型ウィーナーフィルタとの関係を明らかにする.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003313621, CiNii Books ID:AN10013345
  • An ARMA prefiltering approach to adaptive equalization               
    T Shimamura; T Takada; J Suzuki
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, Volume:E83A, Number:10, First page:2035, Last page:2039, Oct. 2000
    In this paper, we propose an adaptive IIR equalizer based on prefiltering techniques. The proposed equalizer has a cascade structure of an ARMA prefilter and an adaptive FIR equalizer. The ARMA prefilter is designed based on the transfer function estimated by the gradient-type instrumental variable algorithm. Simulation results are shown to confirm the performance of the proposed adaptive IIR equalizer. key words: prefilter, instrumental variable algorithm, adaptive IIR equalizer.
    IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Report scientific journal
    ISSN:0916-8508, eISSN:1745-1337, Web of Science ID:WOS:000090137600027
  • システム同定法を用いた雑音にロバストな音声分析(多次元信号処理とその応用・実現論文小特集)               
    有馬由紀; 島村徹也
    Volume:J83-A, Number:12, First page:1455, Last page:1466, 2000
  • システム同定法を用いた雑音にロバストな音声分析(多次元信号処理とその応用・実現論文小特集)               
    有馬由紀; 島村徹也
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J83-A, Number:12, First page:1455, Last page:1466, 2000
  • 対数スペクトルにクリッピングと帯域制限を用いる基本周波数抽出法               
    小林載; 島村徹也
    Volume:J82-A, Number:7, First page:1115, Last page:1122, 1999
  • 対数スペクトルにクリッピングと帯域制限を用いる基本周波数抽出法               
    小林載; 島村徹也
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J82-A, Number:7, First page:1115, Last page:1122, 1999
    copyright(c)1999 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html音声の基本周波数は, 音声処理の幅広い分野で必要とされる特徴パラメータである. 音声信号から基本周波数を抽出する手法は過去に多数提案されているが, あらゆる条件に対し有効な手法はいまだに確立されていない. 本論文では, ケプストラム法を改良することにより雑音環境下における音声に有効となる基本周波数抽出法を提案する. 本手法の特色は, 対数スペクトルのうち特に雑音の影響を受けやすい高周波数成分とスペクトルの谷の部分を除去し, 音声信号の調波構造を明確にした上でケプスドラムを求める点にある. 計算機シミュレーション実,験の結果, 従来法に比べ, 本手法における抽出精度はgross pitch errorを改善することができた. 特に, 周期性を有する雑音が混入された音声の場合に, 本手法により顕著な効果が得られた.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003313374, CiNii Books ID:AN10013345
  • Improvement of LPC Analysis of Speech by Noise Compensation               
    ZHAO Qifang; SHIMAMURA Tetsuya; SUZUKI Jouji
    The Transactions of the Institute of Electronics,Information and Communication Engineers. A, Volume:J81-A, Number:11, First page:1583, Last page:1591, 1998
    copyright(c)1998 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html白色雑音の混入した音声信号から自己相関法を用いて予測係数を求める場合, 自己相関関数R(k)のk=0の付近にその雑音の影響は集中する.従って, 原理的には, 自己相関関数R(0)から雑音パワーを引くことにより雑音補正が行われ, LPC分析の耐雑音性が向上される.しかし, 従来の雑音補正法ではパワーの引きすぎが原因でLPCフィルタが不安定になることがある.従って, その実際的応用は困難と思われる.一方で, スペクトル推定における同様な問題を解決するため, 島村らは反復アルゴリズムを利用した改良雑音補正AR係数推定法を提案した.本論文ではこの改良雑音補正AR係数推定法を音声のLPC分析の雑音低減に応用する.評価実験からこの方法はプリエンファシス(pre-emphasis)されていない音声に対しては有効であるが, プリエンファシスされた音声に対して改善が見られないことが明らかとなった.その理由として, プリエンファシスによって雑音の影響が自己相関関数R(k)のk=1の部分にも及んだことを理論解析で示した。そして, プリエンファシスに影響されない, R(0)とR(1)の双方から雑音パワーを引き去る反復アルゴリズムを導出した.その有効性を計算機シミュレーションで確認している.更にこの方法を拡張し, 白色雑音以外の雑音にも対応できる改善法を提案している.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003312764, CiNii Books ID:AN10013345
  • 対数スペクトルの自己相関関数を用いた搬送波抑圧SSBの離調周波数の推定               
    金子信一郎; 鈴木誠史; 島村徹也
    Volume:J81-D2, Number:7, First page:1501, Last page:1509, 1998
  • 高速スタートアップ等化のためのButler-Cantoni法の適応化               
    島村徹也; 鈴木誠史
    Volume:J81-A, Number:4, First page:622, Last page:630, 1998
  • 雑音補正による音声のLPC分析の改善               
    島村徹也; 趙奇方; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J81-A, Number:11, First page:1583, Last page:1591, 1998
    copyright(c)1998 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html白色雑音の混入した音声信号から自己相関法を用いて予測係数を求める場合, 自己相関関数R(k)のk=0の付近にその雑音の影響は集中する.従って, 原理的には, 自己相関関数R(0)から雑音パワーを引くことにより雑音補正が行われ, LPC分析の耐雑音性が向上される.しかし, 従来の雑音補正法ではパワーの引きすぎが原因でLPCフィルタが不安定になることがある.従って, その実際的応用は困難と思われる.一方で, スペクトル推定における同様な問題を解決するため, 島村らは反復アルゴリズムを利用した改良雑音補正AR係数推定法を提案した.本論文ではこの改良雑音補正AR係数推定法を音声のLPC分析の雑音低減に応用する.評価実験からこの方法はプリエンファシス(pre-emphasis)されていない音声に対しては有効であるが, プリエンファシスされた音声に対して改善が見られないことが明らかとなった.その理由として, プリエンファシスによって雑音の影響が自己相関関数R(k)のk=1の部分にも及んだことを理論解析で示した。そして, プリエンファシスに影響されない, R(0)とR(1)の双方から雑音パワーを引き去る反復アルゴリズムを導出した.その有効性を計算機シミュレーションで確認している.更にこの方法を拡張し, 白色雑音以外の雑音にも対応できる改善法を提案している.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003312764, CiNii Books ID:AN10013345
  • 対数スペクトルの自己相関関数を用いた搬送波抑圧SSBの離調周波数の推定               
    金子信一郎; 鈴木誠史; 島村徹也
    電子情報通信学会論文誌. D-II, 情報・システム, II-情報処理, Volume:J81-D2, Number:7, First page:1501, Last page:1509, 1998
  • 高速スタートアップ等化のためのButler-Cantoni法の適応化               
    島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J81-A, Number:4, First page:622, Last page:630, 1998
    CiNii Articles ID:10015530445
  • Equalisation of time-variant communications channels via channel estimation based approaches               
    T Shimamura; S Semnani; CFN Cowan
    SIGNAL PROCESSING, Volume:60, Number:2, First page:181, Last page:193, Jul. 1997
    For the purpose of tackling the problem of equalisation in a time-variant environment, two novel approaches are developed in which the separation of the channel estimation process from the equalisation process is attempted. Two linear filters - channel estimator and equalisation filter - are used to reconstruct the transmitted sequence. The gradient algorithm with degree-1 least square fading memory prediction is adopted for the channel estimator. Using the results produced by the channel estimator, the coefficients of the equalisation filter are indirectly updated. Computer simulation results show that the two channel estimation based adaptive equalisers provide significant improvement in the case of a second order Markov communication channel model. (C) 1997 Elsevier Science B.V.
    ELSEVIER SCIENCE BV, English
    DOI:https://doi.org/10.1016/S0165-1684(97)00071-6
    DOI ID:10.1016/S0165-1684(97)00071-6, ISSN:0165-1684, CiNii Articles ID:80009850376, Web of Science ID:WOS:A1997XU66900004
  • 品質劣化音声のためのLPC分析の一改良法               
    島村徹也; 國枝伸行; 鈴木誠史
    Volume:J80-A, Number:9, First page:1564, Last page:1566, 1997
  • 対数スペクトルの自己相関関数を利用したピッチ抽出法               
    國枝伸行; 島村徹也; 鈴木誠史
    Volume:J80-A, Number:3, First page:435, Last page:443, 1997
  • 品質劣化音声のためのLPC分析の一改良法               
    島村徹也; 國枝伸行; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J80-A, Number:9, First page:1564, Last page:1566, 1997
  • 対数スペクトルの自己相関関数を利用したピッチ抽出法               
    國枝伸行; 島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J80-A, Number:3, First page:435, Last page:443, 1997
  • 前向き後向き差分関数とフィルタバンクを利用した音声信号の雑音低減               
    國枝伸行; 島村徹也; 鈴木誠史
    Volume:J79-A, Number:3, First page:541, Last page:550, 1996
  • 前向き後向き差分関数とフィルタバンクを利用した音声信号の雑音低減               
    國枝伸行; 島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J79-A, Number:3, First page:541, Last page:550, 1996
    copyright(c)1996 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html我々は相関関数を利用した雑音低減方式について検討している. 先に提案したSPACやSPADは2乗ひずみや高調波ひずみを生じ, 明瞭性を低下させる欠点があった. また前向き後向き差分関数は, ランダム雑音に埋もれた単一正弦波をこうしたひずみを生じることなく強調できる. しかしながら, この関数を音声のような複合波に適用するとひずみが生じる欠点があった. 本論文では, 前向き後向き差分関数を音声強調に利用するため, フィルタバンクを利用した手法を提案する. 本方式では, 音声が調波構造からなることに着目する. すなわち, 音声をフィルタバンクを利用して複数の帯域制限信号に分解し, それぞれの信号に対して前向き後向き差分関数によって高調波を強調する. 強調した高調波を再合成することによって, 音声強調が実現できる. 本論文では, まず前向き後向き差分関数が帯域制限信号に対しても有効であることを示す. そして, 帯域幅が100 Hzのフィルタバンクを構成した提案法により, 疑似音声のSN比を6〜7dB改善できることを計算機シミュレーシヨンによって求めた. 本方式の実際の音声に対する効果を調べた結果, スペクトル包絡のピークを強調できることを確認できた. 試聴実験の結果からは, 提案法がSRACやSPADで生じるひずみを抑え, 雑音低減できるという結果が得られた.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003312403, CiNii Books ID:AN10013345
  • データ拡張を利用する2次元スペクトル推定法とその改良               
    島村徹也; 繆衛国; 鈴木誠史
    Volume:J78-A, Number:8, First page:965, Last page:976, 1995
  • ブラインド等化のためのプレフィルタリング               
    伊藤克子; 島村徹也; 鈴木誠史
    Volume:J78-A, Number:3, First page:323, Last page:331, 1995
  • データ拡張を利用する2次元スペクトル推定法とその改良               
    島村徹也; 繆衛国; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J78-A, Number:8, First page:965, Last page:976, 1995
  • ブラインド等化のためのプレフィルタリング               
    伊藤克子; 島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J78-A, Number:3, First page:323, Last page:331, 1995
  • Enhancement of Single Sinusoidal Signal by Forward and Backward Difference Function               
    KUNIEDA Nobuyuki; SHIMAMURA Tetsuya; SUZUKI Jouji
    The Transactions of the Institute of Electronics,Information and Communication Engineers. A, Volume:J77-A, Number:9, First page:1307, Last page:1311, 1994
    copyright(c)1994 IEICE許諾番号:07RB0174雑音中の単一正弦波をひずみなく強調するための新しい関数として前向き後向き差分関数を定義する.白色雑音の重畳した正弦波を対象に,この関数によるSN比改善特性を求めたところ,自己相関関数よりも優れた効果を得ることができた.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003313184, CiNii Books ID:AN10013345
  • Burg 法のためのデータ予測               
    島村徹也; 鈴木誠史
    Volume:J77-A, Number:8, First page:1182, Last page:1185, 1994
  • 前向き後向き差分関数による単一正弦波信号の強調               
    國枝伸行; 島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J77-A, Number:9, First page:1307, Last page:1311, 1994
    copyright(c)1994 IEICE許諾番号:07RB0174雑音中の単一正弦波をひずみなく強調するための新しい関数として前向き後向き差分関数を定義する.白色雑音の重畳した正弦波を対象に,この関数によるSN比改善特性を求めたところ,自己相関関数よりも優れた効果を得ることができた.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003313184, CiNii Books ID:AN10013345
  • Burg 法のためのデータ予測               
    島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J77-A, Number:8, First page:1182, Last page:1185, 1994
  • 全極型プレフィルタを用いた IIR 型適応等化器               
    伊藤克子; 島村徹也; 八嶋弘幸; 鈴木誠史
    Volume:J76-A, Number:9, First page:1279, Last page:1285, 1993
  • デルタ変調を利用した分析合成系のピッチ伝送方式(ショートノート)               
    岩間智史; 島村徹也; 鈴木誠史
    Volume:J76-A, Number:6, First page:910, Last page:912, 1993
  • 全極型プレフィルタを用いた IIR 型適応等化器               
    伊藤克子; 島村徹也; 八嶋弘幸; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J76-A, Number:9, First page:1279, Last page:1285, 1993
    copyright(c)1993 IEICE許諾番号:07RB0174本論文では,全極型プレフィルタを用いたIIR型適応等化器を提案する.本等化器は,通信路のひずみが大きく,悪条件により等化が困難な場合においても,LMSアルゴリズムを用いて,その等化を可能にする.等化器の構成は,FIR型適応フィルタの前部に推定された通信路の逆フィルタを置く縦続2段構成であり,全体の構成はIIRシステムである.FIR型適応フィルタのみを用いた従来のFIR型適応等化器では,入力信号の相関が大きい場合のLMSアルゴリズムの収束特性の劣化が問題となっていた.本法では,通信路で生じた信号の相関を低減する効果を有する逆フィルタをFIR型適応フィルタの前部に置くことにより,LMSアルゴリズムの収束特性を改善し,トレーニング時間の短縮を実現している.また,構成をIIR型にすることにより,FIR型の場合より低次のシステムで精度の高い等化が可能になる.システムの安定性は,簡単な操作により保証される.計算機シミュレーションでは,提案する等化器の有効性を立証する.
    The Institute of Electronics, Information and Communication Engineers, Japanese
    ISSN:0913-5707, CiNii Articles ID:110003312945, CiNii Books ID:AN10013345
  • デルタ変調を利用した分析合成系のピッチ伝送方式(ショートノート)               
    岩間智史; 島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J76-A, Number:6, First page:910, Last page:912, 1993
  • 1次元および2次元信号のためのスペクトルピーク強調法とその応用               
    島村徹也; 鈴木誠史
    Volume:J75-A, Number:12, First page:1783, Last page:1791, 1992
  • Speech Processing System by Use of Auto-Difference Function - SPAD -               
    KUNIEDA Nobuyuki; SHIMAMURA Tetsuya; SUZUKI Jouji; YASHIMA Hiroyuki
    The Transactions of the Institute of Electronics,Information and Communication Engineers. A, Volume:J75-A, Number:11, First page:1769, Last page:1772, 1992
    copyright(c)1992 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html雑音の重畳した音声の短時間差分関数の波形を逐次接続して出力することにより,雑音レベルの低減を行うことができる.この方式は,従来の自己相関関数を利用した音声処理方式(SPAC)よりも単純な構成で,同程度の雑音低減ができることを示す.
    Japanese
    ISSN:0913-5707, CiNii Articles ID:10006928407, CiNii Books ID:AN10013345
  • Least Squares Adaptive Filter with Complex Coefficients for Ill-Conditioned Adaptive Equalization               
    SHIMAMURA Tetsuya; SUZUKI Jouji
    The Transactions of the Institute of Electronics,Information and Communication Engineers. A, Volume:J75-A, Number:11, First page:1666, Last page:1674, 1992
    copyright(c)1992 IEICE許諾番号:07RB0174本論文では,チャネルのひずみが大きい悪条件下においても,良好な等化を実現することが可能な最小2乗型適応等化器を提案している.本法は,トランスバーサル型等化器のタップ係数を複素係数化し,次数を半減することにより,等化器への入力信号からなる入力相関行列の条件数が低減できることに着目したものである.具体的には,トレーニングモードにおいて,等化器の入出力信号を負の周波数成分を含まない解析信号に変換し,更に比2のデシメーション操作を施した後,複素係数適応フィルタリングを実行する.従来の実係数フィルタリング法に比べ,推定されるタップ係数値の精度が大幅に向上し,また,単位時間当りに必要とされる演算量が低減される.理論解析および計算機シミュレーション実験を通して,提案法の有効性が立証される.
    Japanese
    ISSN:0913-5707, CiNii Articles ID:10006928256, CiNii Books ID:AN10013345
  • 1次元および2次元信号のためのスペクトルピーク強調法とその応用               
    島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J75-A, Number:12, First page:1783, Last page:1791, 1992
  • 差分関数を利用した音声処理法式 - SPAD -               
    國枝伸行; 島村徹也; 鈴木誠史; 八嶋弘幸
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J75-A, Number:11, First page:1769, Last page:1772, 1992
    copyright(c)1992 IEICE許諾番号:07RB0174 http://www.ieice.org/jpn/trans_online/index.html雑音の重畳した音声の短時間差分関数の波形を逐次接続して出力することにより,雑音レベルの低減を行うことができる.この方式は,従来の自己相関関数を利用した音声処理方式(SPAC)よりも単純な構成で,同程度の雑音低減ができることを示す.
    Japanese
    ISSN:0913-5707, CiNii Articles ID:10006928407, CiNii Books ID:AN10013345
  • 悪条件下における適応等化のための複素係数を有する最小2乗型適応フィルタ               
    島村徹也; 鈴木誠史
    電子情報通信学会論文誌. A, 基礎・境界, Volume:J75-A, Number:11, First page:1666, Last page:1674, 1992
    copyright(c)1992 IEICE許諾番号:07RB0174本論文では,チャネルのひずみが大きい悪条件下においても,良好な等化を実現することが可能な最小2乗型適応等化器を提案している.本法は,トランスバーサル型等化器のタップ係数を複素係数化し,次数を半減することにより,等化器への入力信号からなる入力相関行列の条件数が低減できることに着目したものである.具体的には,トレーニングモードにおいて,等化器の入出力信号を負の周波数成分を含まない解析信号に変換し,更に比2のデシメーション操作を施した後,複素係数適応フィルタリングを実行する.従来の実係数フィルタリング法に比べ,推定されるタップ係数値の精度が大幅に向上し,また,単位時間当りに必要とされる演算量が低減される.理論解析および計算機シミュレーション実験を通して,提案法の有効性が立証される.
    Japanese
    ISSN:0913-5707, CiNii Articles ID:10006928256, CiNii Books ID:AN10013345
■ Books and other publications
  • 島村徹也 物理学辞典 (三訂版)               
    2005
  • 島村徹也 物理学辞典 (三訂版)               
    培風館, 2005
  • 池原雅章,島村徹也,真田幸俊 MATLABマルチメディア信号処理 下 音声・画像・通信               
    2004
  • 池原雅章,島村徹也 MATLABマルチメディア信号処理 上 ディジタル信号処理の基礎               
    2004
  • 池原雅章,島村徹也,真田幸俊 MATLABマルチメディア信号処理 下 音声・画像・通信               
    培風館, 2004
  • 池原雅章,島村徹也 MATLABマルチメディア信号処理 上 ディジタル信号処理の基礎               
    培風館, 2004
  • 島村徹也 MATLAB プログラム事例解説 Ⅰ 音声通信-特徴抽出と雑音低減-               
    2001
  • 高橋進一,島村徹也 一次元ディジタル信号処理の基礎               
    2001
  • 島村徹也 MATLAB プログラム事例解説 Ⅰ 音声通信-特徴抽出と雑音低減-               
    トリケップス, 2001
  • 高橋進一,島村徹也 一次元ディジタル信号処理の基礎               
    培風館, 2001
■ Lectures, oral presentations, etc.
  • Equalization of Time-Variant Communications Channels via Adaptive AR Prefiltering               
    2009
  • スペクトル引き算を利用したウィナーフィルタによる画像復元               
    2009
  • 改良雑音スペクトル推定を用いたウィナーフィルタリングによる画像復元               
    2009
  • 反復適応ウィナーフィルタを用いた画像復元               
    2009
  • Dual Adaptive Pre-Whitening Filters for LMS Algorithm               
    2009
  • Time Delay Estimation of Arrival and Spectrum Subtraction for Acoustic Dual-Microphone Systems               
    2009
  • Image Restoration via Wiener Filtering with Improved Noise Estimation               
    2009
  • Equalization of Time-Variant Communications Channels via Adaptive AR Prefiltering               
    Proceedings of WRI World Congress on Computer Science and Information Engineering, 2009
  • スペクトル引き算を利用したウィナーフィルタによる画像復元               
    電子情報通信学会2009総合大会講演論文集, 2009
  • 改良雑音スペクトル推定を用いたウィナーフィルタリングによる画像復元               
    電子情報通信学会2009総合大会講演論文集, 2009
  • 反復適応ウィナーフィルタを用いた画像復元               
    電子情報通信学会2009総合大会講演論文集, 2009
  • Dual Adaptive Pre-Whitening Filters for LMS Algorithm               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2009
  • Time Delay Estimation of Arrival and Spectrum Subtraction for Acoustic Dual-Microphone Systems               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2009
  • Image Restoration via Wiener Filtering with Improved Noise Estimation               
    Proceedings of WSEAS International Conference on Signal Processing, Robotics and Automation, 2009
  • Amplitude Banded Technique and Parallel Structure for Godard and Sato Algorithms of Blind Channel Equalization               
    2008
  • High Pitch Source Isolation Using Complex Cepstrum in the Autocorrelation Domain               
    2008
  • 双対の適応白色化フィルタを用いたLMSアルゴリズム               
    2008
  • 線形予測誤差を用いた骨導音声の品質改善               
    2008
    Poster presentation
  • An Efficient and Effective Variable Step Size NLMS Algorithm               
    2008
  • Adaptive Line Enhancer for Time Delay Estimation of Ultrasonic Echoes               
    2008
  • Amplitude-Division Parallel LMS Estimator               
    2008
  • Convergence Evaluation of a Variable Step-Size LMSE Adaptive Switching Algorithm               
    2008
  • 高騒音環境下における骨導音声を用いた話者認識               
    2008
  • デュアルマイクロホンでの時間遅延を利用した音声強調手法               
    2008
    Poster presentation
  • 縦続型適応非線形予測器を用いた音声信号の予測分析               
    2008
  • Quality Improvement of Bone-Conducted Speech Using Linear Prediction Analysis Filter               
    2008
  • Iterative Cross-Correlation Method for Time Delay Estimation               
    2008
  • Bone-Conducted Speech for Speaker Verification               
    2008
  • Wavelet Based Denoising for Images Degraded by Poisson Noise               
    2008
  • Amplitude Banded Technique and Parallel Structure for Godard and Sato Algorithms of Blind Channel Equalization               
    Proceedings of International Conference on Computer and Information Technology, 2008
  • High Pitch Source Isolation Using Complex Cepstrum in the Autocorrelation Domain               
    Proceedings of IEEE Asia Pacific Conference on Circuits and Systems, 2008
  • 双対の適応白色化フィルタを用いたLMSアルゴリズム               
    信号処理シンポジウム講演論文集, 2008
  • 線形予測誤差を用いた骨導音声の品質改善               
    信号処理シンポジウム講演論文集, 2008
    Poster presentation
  • An Efficient and Effective Variable Step Size NLMS Algorithm               
    Proceedings of Asilomar Conference on Signals, Systems and Computers, 2008
  • Adaptive Line Enhancer for Time Delay Estimation of Ultrasonic Echoes               
    Proceedings of International Symposium on Communication and Information Technology, 2008
  • Amplitude-Division Parallel LMS Estimator               
    Proceedings of IEEE International Midwest Symposium on Circuits and Systems, 2008
  • Convergence Evaluation of a Variable Step-Size LMSE Adaptive Switching Algorithm               
    Proceedings of IEEE International Networking and Communications Conference, 2008
  • 高騒音環境下における骨導音声を用いた話者認識               
    日本音響学会春期研究発表会講演論文集, 2008
  • デュアルマイクロホンでの時間遅延を利用した音声強調手法               
    日本音響学会春期研究発表会講演論文集, 2008
    Poster presentation
  • 縦続型適応非線形予測器を用いた音声信号の予測分析               
    日本音響学会春期研究発表会講演論文集, 2008
  • Quality Improvement of Bone-Conducted Speech Using Linear Prediction Analysis Filter               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2008
  • Iterative Cross-Correlation Method for Time Delay Estimation               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2008
  • Bone-Conducted Speech for Speaker Verification               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2008
  • Wavelet Based Denoising for Images Degraded by Poisson Noise               
    Proceedings of IASTED International Conference on Biomedical Engineering, 2008
  • Amplitude Banded Sato Algorithm for Blind Channel Equalization               
    2007
    Poster presentation
  • Image Denoising for Poisson Noise by Pixel Values Based Division and Wavelet Shrinkage               
    2007
  • Equalization with Amplitude Banded LMS Adaptation for Stationary Channels               
    2007
  • Performance of the Amplitude Banded LMS Equalizer on Stationary Channels               
    2007
    Poster presentation
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    2007
  • ディジタル無線通信における雑音にロバストな検波のための一手法               
    2007
  • Restoration of Bone-Conducted Speech with the Wiener Filter and Long-Term Spectra               
    2007
  • Magnitude Spectral Subtraction with DFTLMS Algorithm for Adaptive Line Enhancer               
    2007
  • Indirect Cross-Correlation Method for Time Delay Estimation               
    2007
  • Adaptive Non-Linear Prediction with Order Statistics for Speech in Impulsive Noise               
    2007
  • Discrete Cosine Transform Domain Parallel LMS Equalizer               
    2007
  • Amplitude Banded Sato Algorithm for Blind Channel Equalization               
    Proceedings of IEEE International Conference on Signal Processing and Communications, 2007
    Poster presentation
  • Image Denoising for Poisson Noise by Pixel Values Based Division and Wavelet Shrinkage               
    Proceedings of International Symposium on Nonlinear Theory and Its Applications, 2007
  • Equalization with Amplitude Banded LMS Adaptation for Stationary Channels               
    Proceedings of IASTED International Conference on Signal and Image Processing, 2007
  • Performance of the Amplitude Banded LMS Equalizer on Stationary Channels               
    Proceedings of IEEE International Workshop on Nonlinear Dynamics of Electronic Systems, 2007
    Poster presentation
  • Discrete Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Proceedings of NICOGRAPH International 2007, 2007
  • ディジタル無線通信における雑音にロバストな検波のための一手法               
    電子情報通信学会総合大会講演論文集, 2007
  • Restoration of Bone-Conducted Speech with the Wiener Filter and Long-Term Spectra               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2007
  • Magnitude Spectral Subtraction with DFTLMS Algorithm for Adaptive Line Enhancer               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2007
  • Indirect Cross-Correlation Method for Time Delay Estimation               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2007
  • Adaptive Non-Linear Prediction with Order Statistics for Speech in Impulsive Noise               
    Proceedings on WSEAS International Conference on Circuits, Systems, Signal and Telecommunications, 2007
  • Discrete Cosine Transform Domain Parallel LMS Equalizer               
    Proceedings on WSEAS International Conference on Circuits, Systems, Signal and Telecommunications, 2007
  • A Parallel Estimator with LMS and RLS Adaptation for Fast Fading Channels               
    2006
  • Adaptive Non-Linear Prediction with Order Statistics for Speech Signals in Mixture Noise               
    2006
  • Active Noise Control Using A Refined Filtering Approach               
    2006
  • Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    2006
  • Autoregressive Moving Average (ARMA) Analysis of Speech by Modeling the Active Voice Source               
    2006
  • Learning for Bone-Conducted Speech via Adaptive and Neural Filters               
    2006
  • Pitch Determination using Aligned AMDF               
    2006
  • A Harsh Noise Assessment Measure for Speech Enhancement               
    2006
  • Improving Bone-Conducted Speech Quality via Neural Network               
    2006
  • SIDOモデルを用いたブラインド等化に関する一検討               
    2006
  • 反復スペクトル引き算法による雑音重畳画像からの復元               
    2006
  • Reconstruction Filter design for Bone-Conducted Speech               
    2006
  • 骨導音声の品質改善について (その1)               
    2006
    Poster presentation
  • 反復RFアルゴリズムを利用したリアルタイム騒音制御               
    2006
    Poster presentation
  • 縦列型適応フィルタを用いたアクティブノイズコントロールシステムの提案               
    2006
  • 線形予測フィルタを用いた適応音声強調               
    2006
    Poster presentation
  • 騒音環境下での適応フィルタによる骨導音声の品質改善               
    2006
    Poster presentation
  • スペクトル引き算のための雑音の煩雑さを考慮した雑音評価法               
    2006
    Poster presentation
  • A Study on Normalized LMS Algorithm Using Refined Filtering Technique               
    2006
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    2006
  • Adaptive Time-Variant Channel Equalization Using Phase-Banded LMS Algorithm               
    2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    2006
  • A Parallel Estimator with LMS and RLS Adaptation for Fast Fading Channels               
    Proceedings of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, 2006
  • Adaptive Non-Linear Prediction with Order Statistics for Speech Signals in Mixture Noise               
    Proceedings of IEEE International Symposium on Intelligent Signal Processing and Communication Systems, 2006
  • Active Noise Control Using A Refined Filtering Approach               
    Proceedings of the 35th International Congress and Exposition on Noise Control Engineering, 2006
  • Wavelet Based Keyframe Extraction Method from Motion Capture Data               
    Proceedings on Asia Digital Art and Design Association, 2006
  • Autoregressive Moving Average (ARMA) Analysis of Speech by Modeling the Active Voice Source               
    Proceedings of International Conference on Signals and Electronic Systems, 2006
  • Learning for Bone-Conducted Speech via Adaptive and Neural Filters               
    Proceedings of International Conference on Signals and Electronic Systems, 2006
  • Pitch Determination using Aligned AMDF               
    Proceedings of International Conference on Spoken Language Processing, 2006
  • A Harsh Noise Assessment Measure for Speech Enhancement               
    Proceedings of European Conference on Signal Processing, 2006
  • Improving Bone-Conducted Speech Quality via Neural Network               
    Proceedings of IEEE International Symposium on Signal Processing and Information Technology, 2006
  • SIDOモデルを用いたブラインド等化に関する一検討               
    電子情報通信学会技術研究報告, 2006
  • 反復スペクトル引き算法による雑音重畳画像からの復元               
    電子情報通信学会技術研究報告, 2006
  • Reconstruction Filter design for Bone-Conducted Speech               
    Proceedings of International Conference on Spoken Language Processing, 2006
  • 骨導音声の品質改善について (その1)               
    日本音響学会2005年春季研究発表会講演論文集, 2006
    Poster presentation
  • 反復RFアルゴリズムを利用したリアルタイム騒音制御               
    日本音響学会春季研究発表会講演論文集, 2006
    Poster presentation
  • 縦列型適応フィルタを用いたアクティブノイズコントロールシステムの提案               
    日本音響学会春季研究発表会講演論文集, 2006
  • 線形予測フィルタを用いた適応音声強調               
    日本音響学会春季研究発表会講演論文集, 2006
    Poster presentation
  • 騒音環境下での適応フィルタによる骨導音声の品質改善               
    日本音響学会春季研究発表会講演論文集, 2006
    Poster presentation
  • スペクトル引き算のための雑音の煩雑さを考慮した雑音評価法               
    日本音響学会春季研究発表会講演論文集, 2006
    Poster presentation
  • A Study on Normalized LMS Algorithm Using Refined Filtering Technique               
    Proceedings of 5th WSEAS International Conference on Signal Processing, Robotics and Automation, 2006
  • Noise Estimation Using Multifrequency Regions for Spectral Subtraction               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Adaptive Time-Variant Channel Equalization Using Phase-Banded LMS Algorithm               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Active Noise Control Using Cascaded Adaptive Filters               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2006
  • Equalization of Time Variant Multipath Channels Using Channel Estimation Based Classification Techniques               
    2005
  • A Parallel Estimator with LMS Adaptation for Fast Fading Channels               
    2005
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    2005
  • Speech Enhancement Using a Technique of Adaptive Bias Suppression               
    2005
    Poster presentation
  • Voice Source Modeling for Accurate Speech Analysis               
    2005
  • Quality Improvement of Bone-Conducted Speech               
    2005
  • A Reconstruction Filter for Bone-Conducted Speech               
    2005
  • Restoration from Image Degraded by White Noise Based on Iterative Spectral Subtraction Method               
    2005
    Poster presentation
  • Linear Prediction Using Homomorphic Deconvolution in the Autocorrelation Domain               
    2005
    Poster presentation
  • Adaptive Nonlinear Predictive Analysis for Speech Using a Cascaded LMS-VSLMS Predictor               
    2005
  • Sinusoidal Time Delay Tracking by a Self-tuned LMS Filter with Interpolation Based on System Response Coefficient Ratios               
    2005
  • LMS-VSLMS縦列接続による適応非線形予測分析               
    2005
    Poster presentation
  • 白色雑音とインパルス雑音の混合環境下における音声信号の適応非線形予測分析               
    2005
    Poster presentation
  • 雑音スペクトルの多重処理を用いた改良スペクトル引き算法による音声強調               
    2005
    Poster presentation
  • 適応バイアス抑制技術を用いた音声強調               
    2005
  • 骨導音声の品質改善について (その2)               
    2005
  • アクティブノイズコントロールへの改良正規化LMSアルゴリズムの適用               
    2005
  • White Noise Removal in Image by Iterative Spectral Subtraction Method               
    2005
  • Noise Removal for Image Degraded by Poisson Noise: A Pixel Values Based Division Approach               
    2005
  • Equalization of Time Variant Multipath Channels Using Channel Estimation Based Classification Techniques               
    Proceedings of IEEE Region 10 International Conference on Electrical and Electronic Technology, 2005
  • A Parallel Estimator with LMS Adaptation for Fast Fading Channels               
    Proceedings of IEEE Region 10 International Conference on Electrical and Electronic Technology, 2005
  • Spectral Subtraction with Non-Stationary Noise Estimation Utilizing Harmonic Structure               
    Proceedings of WSEAS International Conference on Electronics, Control and Signal Processing, 2005
  • Speech Enhancement Using a Technique of Adaptive Bias Suppression               
    Proceedings of Asilomar Conference on Signals, Systems and Computers, 2005
    Poster presentation
  • Voice Source Modeling for Accurate Speech Analysis               
    Proceedings of Asilomar Conference on Signals, Systems and Computers, 2005
  • Quality Improvement of Bone-Conducted Speech               
    Proceedings of European Conference on Circuit Theory and Design, 2005
  • A Reconstruction Filter for Bone-Conducted Speech               
    Proceedings of IEEE International Midwest Symposium on Circuits and Systems, 2005
  • Restoration from Image Degraded by White Noise Based on Iterative Spectral Subtraction Method               
    Proceedings of IEEE International Symposium on Circuits and Systems, 2005
    Poster presentation
  • Linear Prediction Using Homomorphic Deconvolution in the Autocorrelation Domain               
    Proceedings of IEEE International Symposium on Circuits and Systems, 2005
    Poster presentation
  • Adaptive Nonlinear Predictive Analysis for Speech Using a Cascaded LMS-VSLMS Predictor               
    Proceedings of IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing, 2005
  • Sinusoidal Time Delay Tracking by a Self-tuned LMS Filter with Interpolation Based on System Response Coefficient Ratios               
    Proceedings of IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing, 2005
  • LMS-VSLMS縦列接続による適応非線形予測分析               
    日本音響学会2005年春季研究発表会講演論文集, 2005
    Poster presentation
  • 白色雑音とインパルス雑音の混合環境下における音声信号の適応非線形予測分析               
    日本音響学会2005年春季研究発表会講演論文集, 2005
    Poster presentation
  • 雑音スペクトルの多重処理を用いた改良スペクトル引き算法による音声強調               
    日本音響学会2005年春季研究発表会講演論文集, 2005
    Poster presentation
  • 適応バイアス抑制技術を用いた音声強調               
    日本音響学会2005年春季研究発表会講演論文集, 2005
  • 骨導音声の品質改善について (その2)               
    日本音響学会2005年春季研究発表会講演論文集, 2005
  • アクティブノイズコントロールへの改良正規化LMSアルゴリズムの適用               
    日本音響学会2005年春季研究発表会講演論文集, 2005
  • White Noise Removal in Image by Iterative Spectral Subtraction Method               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2005
  • Noise Removal for Image Degraded by Poisson Noise: A Pixel Values Based Division Approach               
    Proceedings of RISP International Workshop on Nonlinear Circuits and Signal Processing, 2005
  • 非最小位相通信路における線形トランスバーサル等化器の特性改善 -係数および遅延量の同時適応-               
    2004
  • Nonlinear Predictive Analysis of Speech by Iterative Approach               
    2004
  • Pitch Synchronous Addition and Extension for Linear Predictive Analysis of Noisy Speech               
    2004
  • Non-Stationary Noise Estimation Utilizing Harmonic Structure for Spectral Subtraction               
    2004
    Poster presentation
  • Noise-Robust Fundamental Frequency Extraction Method Based on Exponentiated Band-Limited Amplitude Spectrum               
    2004
  • Adaptive Non-linear Prediction of Speech in Impulse Noise               
    2004
    Poster presentation
  • Improved model of SPAC (Speech Processing System by use of autocorrelation function) utilizing spectral subtraction as preprocessing               
    2004
    Poster presentation
  • A Novel Amplitude Banded RLS Algorithm for Equalization of Time Variant Multipath Channels               
    2004
  • Equalizer-aided time delay tracking based on finite differences               
    2004
  • An adaptive Butler-Cantoni based time delay estimation (ABCTDE) method- IIR whitening filter approach               
    2004
  • 非最小位相通信路における線形トランスバーサル等化器の特性改善 -係数および遅延量の同時適応-               
    Proc. 第19回信号処理シンポジウム講演論文集, 2004
  • Nonlinear Predictive Analysis of Speech by Iterative Approach               
    Proc. 12th Europian Signal Processing Conf., 2004
  • Pitch Synchronous Addition and Extension for Linear Predictive Analysis of Noisy Speech               
    Proc. 6th Nordic Signal Processing Symposium, 2004
  • Non-Stationary Noise Estimation Utilizing Harmonic Structure for Spectral Subtraction               
    Proceedings of Asilomar Conference on Signals, Systems and Computers, 2004
    Poster presentation
  • Noise-Robust Fundamental Frequency Extraction Method Based on Exponentiated Band-Limited Amplitude Spectrum               
    Proc. 47th IEEE International Midwest Symposium on Circuits and Systems, 2004
  • Adaptive Non-linear Prediction of Speech in Impulse Noise               
    Proc. 18th International Congress on Acoustics, 2004
    Poster presentation
  • Improved model of SPAC (Speech Processing System by use of autocorrelation function) utilizing spectral subtraction as preprocessing               
    Proc. 18th International Congress on Acoustics, 2004
    Poster presentation
  • A Novel Amplitude Banded RLS Algorithm for Equalization of Time Variant Multipath Channels               
    Proceedings of IFAC Workshop on Adaptation and Learning in Control and Signal Processing, 2004
  • Equalizer-aided time delay tracking based on finite differences               
    Proc. 19th IEICE Signal Processing Symposium, 2004
  • An adaptive Butler-Cantoni based time delay estimation (ABCTDE) method- IIR whitening filter approach               
    Proceedings of IEEE International Symposium on Circuits and Systems, 2004
■ Research projects
  • -               
    Competitive research funding
  • -               
    Competitive research funding
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