KINDAI UNIVERSITY


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NAKASAKO Noboru

Profile

FacultyDepartment of Computational Systems Biology / Graduate School of Biology-Oriented Science and Technology
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/441-nakasako-noboru.html
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Last Updated :2020/06/01

Education and Career

Education

  •  - 1986 , Hiroshima University
  •  - 1986 , Hiroshima University, Graduate School, Division of Engineering
  •  - 1982 , Hiroshima University, Faculty of Engineering
  •  - 1982 , Hiroshima University, Faculty of Engineering

Academic & Professional Experience

  •   1994 ,  - 2002 , Faculty of Biology-Oriented Science and Technology, Kindai University
  •   1990 ,  - 1994 , lecturer, Department of Electrical Engineering, Hiroshima Institute of Technology
  •   1986 ,  - 1990 , Research Assistant, Department of Electrical Engineering, Hiroshima Institute of Technology,
  •   1992 ,  - 1993 , Faculty of Eng., Kinki Univ., Lecturer
  •   1984 ,  - 1985 , Faculty of Eng., Kinki Univ., Lecturer
  • Kinki Univ., Associate Professor
  • Assistant Professor
  • Research Assistant

Research Activities

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Measurement engineering
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Control and systems engineering
  • Informatics, Statistical science
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Communication and network engineering

Research Interests

  • System Engineering, Information and Communication Engineering, Electric Measurements and Control Engineering

Published Papers

  • Response of effective voltage-scaling factors in alpha band EEFs under affective picture stimuli, TOMINAGA Shigeru, YOSHIDA Hisashi, NAKASAKO Noboru, IWAKI Tatsuya, IEICE Trans. Infomation and Systems (Japanese Edition), IEICE Trans. Infomation and Systems (Japanese Edition), J102-D(5), 399 - 410, May 2019 , Refereed
  • A Realization of Acoustic Distance Measurement System Based on Phase Interference Using Cross-Spectral Method, Song ChangRyung, Toshihiro Shinohara, Tetsuji Uebo, Noboru Nakasako, IEEJ Transactions on Electronics, Information and Systems, IEEJ Transactions on Electronics, Information and Systems, 138(10), 1223 - 1229, Oct. 2018 , Refereed
  • Implementation of a One-Channel Acoustic Distance Measurement Method Using the Cross-Spectrum of Actual and Pseudo Observations, Changryung Song, Toshihiro Shinohara, Tetsuji Uebo, Noboru Nakasako, ICIC Express Letters, Part B: Applications, ICIC Express Letters, Part B: Applications, 9(9), 899 - 906, Sep. 2018 , Refereed
  • Consideration of Acoustic Distance Measurement Using the Hilbert Transform of 2ch Observations with a Linear Chirp Signal for Multiple Targets, Noboru Nakasako, Kohsuke Sakaguchi, Toshihiro Shinohara, Tetsuji Uebo, ICIC Express Letters, Part B: Applications, ICIC Express Letters, Part B: Applications, 9(8), 737 - 745, Aug. 2018 , Refereed
  • A Countermeasure for Ambient Noise in Acoustic Distance Measurement Using Cross-spectrum between 2ch Obsrevations with Analytic Signal Composed of Linear Chirps, Noboru Nakasako, Kohsuke Sakaguchi, Shinya Honda, Toshihiro Shinohara, Tetsuji Uebo, IEEJ Transactions on Electronics, Information and Systems, IEEJ Transactions on Electronics, Information and Systems, 137(11), 1443 - 1444, Nov. 2017 , Refereed
  • Fundamental study on acoustic distance measurement using cross-spectrum between 2ch observed signals of linear chirp sound, Noboru Nakasako, Shinya Honda, Toshihiro Shinohara, Testuji Uebo, Trans. of the Institute of Systems, Control and Information Engineers, Trans. of the Institute of Systems, Control and Information Engineers, 30(9), 339 - 346, Sep. 2017 , Refereed
  • Estimation of Distance to Sound Source in Noisy Environment Using Human Voice as Sound Source (Introduction of CrossSpectral Method between Actual and Pseudo Observed Waves and of Synchronous Addition), Shinya HONDA, Toshihiro SHINOHARA, Tetsuji UEBO, Masato NAKAYAMA, Noboru NAKASAKO, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J100-A(7), 295 - 298, Jul. 2017 , Refereed
  • Acoustic Distance Measurement Based on Phase Interference Between Direct and Reflected Ultrasonic Waves (Estimation for Close Range Using Single Transducer), Tomofumi Nakano, Noboru Nakasako, Toshihiro Shinohara, Tetsuji Uebo, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 136(11), 1551 - 1552, Nov. 2016 , Refereed
  • Estimation of the distance to sound source based on phase interference using cross-spectrum between actual and pseudo observed waves of a single-channel microphone, Shinya Honda, Noboru Nakasako, Toshihiro Shinohara, Tetsuji Uebo, Masato Nakayama, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 136(11), 1525 - 1531, Nov. 2016 , Refereed
  • Range and Velocity Estimation to a Target with Uniform Motion by Utilizing Acoustical Distance Measurement Method Based on Interference between Transmitted and Reflected Waves and by Introducing Frame Processing, HANABUSA Shimpei, NAKASAKO Noboru, NAKAYAMA Masato, SHINOHARA Toshihiro, UEBO Tetsuji, Trans. of the Institute of Systems, Control and Information Engineers, Trans. of the Institute of Systems, Control and Information Engineers, 60(5), 216 - 224, May 2016 , Refereed
  • Distance Measurement to Target Based on Phase Interference Using Audible Sound ---A Principle of Acoustic Distance Measurement and Its Progress(Review Paper), NAKASAKO Noboru, UEBO Tetsuji, SHINOHRA Toshihiro, Fundamentals Review, Fundamentals Review, 9(4), 330 - 339, Apr. 2016
  • Acoustic Distance Measurement Method Using 2ch Microphones Measurable from 0m Based on Phase Interference and Removal of DC Component, Kazuhiro SUZUKI, Noboru NAKASAKO, Masato NAKAYAMA, Toshihiro SHINOHARA, Tetsuji UEBO, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 135(11), 1349 - 1350, Nov. 2015 , Refereed
  • Distance Estimation Based on Interference of Audible Linear Chirp Signal:—Performance Evaluation in Noisy Environments and a Trial for Noise Reduction—, Noboru Nakasako, Shimpei Hanabusa, Toshihiro Shinohara, Masato Nakayama, Tetsuji Uebo, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 134(11), 1926 - 1927, Nov. 2014 , Refereed
  • Distance Measurement Method Effective from 0 m Using Phase Interference of Audible Sound, Noboru Nakasako, Toshihiro Shinohara, Keiji Kawanishi, Tetsuji Uebo, ELECTRONICS AND COMMUNICATIONS IN JAPAN, ELECTRONICS AND COMMUNICATIONS IN JAPAN, 97(8), 24 - 31, Aug. 2014
    Summary:In many engineering fields, distance to target is very important information. Typical distance measurement methods use the time delay between transmitted and reflected waves, but it is difficult to estimate short distances. A method for measuring short distances using a standing wave generated by phase interference of transmitted and reflected waves is known in the field of microwave radar. This method is given in a very simple form in which the distance between the microphone and target is estimated as the peak value of the range spectrum, which can be obtained from the Fourier transform of the power spectrum of the observed wave. However, since the minimum measurable distance depends on the bandwidth of the transmitted wave, measurement of shorter distances requires greater bandwidth of the transmitted wave. This paper describes a new distance estimation method that is effective from 0 m based on the phase interference of transmitted and reflected audible sound. Specifically, we introduce an analytic signal instead of the power spectrum and examine the validity and effectiveness of our method by applying it to an actual sound field. (C) 2014 Wiley Periodicals, Inc.
  • Separation of artifacts mixed in the EEGs when eating with use of independent vector analysis (IVA), TOMINAGA SHIGERU, YOSHIDA HISASHI, NAKASAKO NOBORU, 電子情報通信学会技術研究報告, 電子情報通信学会技術研究報告, 114(51(MBE2014 1-11)), 37 - 42, May 17 2014
  • The Object Localization by Acoustic Distance Measurement Method Based on Phase Interference with Cross-Spectral Method, Kazuhiro SUZUKI, Noboru NAKASAKO, Masato NAKAYAMA, Toshihiro SHINOHARA, Tetsuji UEBO, Manabu FUKUSHIMA, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J97-A(4), 343 - 346, Apr. 2014 , Refereed
  • A study on superimposition mode of mastication EMG on EEG, and its trial separation with use of FDICA, TOMINAGA SHIGERU, YOSHIDA HISASHI, NAKASAKO NOBORU, 電子情報通信学会技術研究報告, 電子情報通信学会技術研究報告, 113(373(MBE2013 75-92)), 57 - 62, Dec. 14 2013
  • A study on EEG lead systems, artifacts mixed into the EEGs when eating, and their classification methods based on ICA, TOMINAGA SHIGERU, YOSHIDA HISASHI, NAKASAKO NOBORU, 電子情報通信学会技術研究報告, 電子情報通信学会技術研究報告, 113(223(NC2013 22-45)), 113 - 118, Sep. 17 2013
  • Acoustic distance measurement method based on phase interference using the cross-spectral method, M. Nakayama, N. Nakasako, T. Uebo, M. Fukushima, Acoustical Science and Technology, Acoustical Science and Technology, 34(3), 197 - 205, May 2013 , Refereed
  • Multiple-nulls-steering beamformer based on both talker and noise direction-of-arrival estimation, M. Nakayama, T. Nishiura, Y. Yamashita, N. Nakasako, Acoustical Science and Technology, Acoustical Science and Technology, 34(2), 80 - 88, Mar. 2013 , Refereed
  • Distance Estimation Method Measurable from 0m Using Phase Interference of Audible Sound, Noboru Nakasako, Toshihiro Shinohara, Keiji Kawanishi, Tetsuji Uebo, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 132(11), 1749 - 1755, Nov. 2012 , Refereed
  • Range and Velocity Estimation Based on Phase Interference of Subband-divided and Time-delayed Impulse Sound to a Moving Target, Masato Nakayama, Noboru Nakasako, Toshihiro Shinohara, Yuma Neki, Tetsuji Uebo, Takanobu Nishiura, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 132(11), 1774 - 1775, Nov. 2012 , Refereed
  • Acoustic Distance Measurement Method Measurable from 0 m Based on the Interference between Transmitted and Reflected Waves Using Power and Phase Spectra of Single Channel Observations, Noboru Nakasako, Keiji Kawanishi, Toshihiro Shinohara, Tetsuji Uebo, Masato Nakayama, Proc. of the 2012 IEEE International Conference on Signal Processing, Communications and Computing, Proc. of the 2012 IEEE International Conference on Signal Processing, Communications and Computing, 1 - 6, Aug. 2012 , Refereed
  • Acoustic distance measurement method based on interference of speech presented by a dialogue system, Masato Nakayama, Noboru Nakasako, Yuma Neki, Tetsuji Uebo, Takanobu Nishiura, Proc. of the 2012 IEEE International Conference on Signal Processing, Communications and Computing, Proc. of the 2012 IEEE International Conference on Signal Processing, Communications and Computing, 1 - 6, Aug. 2012 , Refereed
  • Robust Acoustic Distance Maesurement Method Based on Synchronous Addition and Specral Subtraction in Noisy Environments, Masato Nakayama, Shimpei Hanabusa, Noboru Nakasako, Toshihiro Shinohara, Tetsuji Uebo, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 131(11), 1864 - 1870, Nov. 2011 , Refereed
  • A Trial Implementation of a Distance Estimation Method Based on Standing Waves of Audible Sound, Norimitsu Ohmata, Tetsuji Uebo, Noboru Nakasako, Toshihiro Shinohara, ELECTRICAL ENGINEERING IN JAPAN, ELECTRICAL ENGINEERING IN JAPAN, 177(2), 41 - 48, Nov. 2011
    Summary:In many engineering fields, the distance to target is very important information. In a typical method, the distance is estimated by measuring the time delay between transmitted and reflected waves. However, it is difficult to estimate short distances with a method like this. In the field of microwave radar, a method using standing waves to measure short distances and multiple targets is known. We have applied this method to distance estimation using audible sound and have shown the validity of this method by our simulations and experiments. In this paper, we present a prototype system for distance estimation in which this method is implemented, and evaluate the performance of this system by experiments in an actual sound field. (C) 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(2): 41-48, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21160
  • A study of acoustic distance measurement method based on phase interference using synchronous subtraction processing, Masato NAKAYAMA, Shimpei HANABUSA, Noboru NAKASAKO, Toshihiro SHINOHARA, Tetsuji UEBO, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J94-A(8), 676 - 679, Aug. 2011 , Refereed
  • Three-dimensional sound field reproduction method based on acoustic distance measurement method using near loudspeakers on the right and left sides, Masato NAKAYAMA, HIROHATA Kazuki, Noboru NAKASAKO, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J94-A(5), 313 - 322, May 2011 , Refereed
  • Talker localization based on interference between transmitted and reflected audible, Masato Nakayama, Noboru Nakasako, Toshihiro Shinohara, Tetsuji Uebo, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 130(11), 1994 - 2000, Nov. 2010 , Refereed
  • Distance estimation using audible sound --Principle of distance estimation based on standing wave, Noboru NAKASAKO, Tetsuji UEBO, Toshihiro SHINOHARA, SYSTEMS, CONTROL AND INFORMATION, SYSTEMS, CONTROL AND INFORMATION, 54(8), 314 - 319, Aug. 2010
  • Distance Estimation to Multiple Targets Using Band-Limited Noise Signal, Tetsuji Uebo, Noboru Nakasako, Norimitsu Ohmata, Hanae Itagaki, ELECTRONICS AND COMMUNICATIONS IN JAPAN, ELECTRONICS AND COMMUNICATIONS IN JAPAN, 93(7), 53 - 60, Jul. 2010
    Summary:In many engineering fields, the distance to target is fundamental and very important information. Acoustical signals, such as audible sound or ultrasound, often play an essential role in measurement of distance. To measure distance, the time delay of the reflected wave measured with reference to the transmitted pulse wave, that is, the time-of-flight (TOF), is typically used. However, this method cannot measure short distances because the transmitted wave, which has not attenuated enough at the time of reception of the reflected waves, suppresses the reflected waves for a short distance. Meanwhile, in microwave radar research, a novel method using standing waves has been recently proposed in order to measure the distances to multiple targets, even if short. We apply the fundamental principle of this method to the estimation of short distances for multiple targets using audible sound. In this paper, we focus our attention on audible band-limited noise. To verify the validity and effectiveness of our method, we perform computer simulations and experiments. It is confirmed that short distances to multiple targets, such as the distances to two targets located 0.1 and 1 m away, can be estimated properly by our method. (C) 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(7): 53-60, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10248
  • Fundamental consideration on distance estimation based on interference between transmitted and reflected sound, Noboru Nakasako, Toshihiro Shinohara, Atsushi Mori, Tetsuji Uebo, The Jounal of the INCE (Institute of Noise Control Engineers) of Japan, The Jounal of the INCE (Institute of Noise Control Engineers) of Japan, 34(2), 186 - 194, Apr. 2010 , Refereed
  • Distance estimation based on interference of audile linear chirp signal, Shimpei Hanabusa, Tetsuji Uebo, Yuuta Tsuchida, Toshihiro Shinohara, Noboru Nakasako, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 129(11), 2027 - 2033, Nov. 2009 , Refereed
  • A Study of Prosodic Features of Emotional Speech Based on the Auditory Impressions, Memoirs of the School of Biology-Oriented Science and Technology of Kinki University, Memoirs of the School of Biology-Oriented Science and Technology of Kinki University, (23), 1 - 14, Mar. 2009 , Refereed
  • A trail on implementation of distance estimation method based on standing wave of audble sound, Norimitsu Ohmata, Tetsuji Uebo, Noboru Nakasako, Toshihiro Shinohara, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 129(2), 314 - 319, Feb. 2009 , Refereed
  • Distance measurement based on standing wave for band-limited audible sound with random phase, T. Uebo, N. Nakasako, N. Ohmata, A. Mori, Acoustical Science and Technology, Acoustical Science and Technology, 30(1), 18 - 24, Jan. 2009 , Refereed
  • Distance estimation to multiple targets using band-limted noise signal, T. Uebo, N. Nakasako, N. Ohmata, H. Itagaki, IEEJ transactions on electronics, information and systems, IEEJ transactions on electronics, information and systems, 128(7), 1117 - 1122, Jul. 2008 , Refereed
  • Fundamental consideration on distance estimation using acoustical standing wave, N. Nakasako, T. Uebo, A. Mori, N. Ohmata, IEICE Trans. Fundamentals, IEICE Trans. Fundamentals, E91-A(4), 1218 - 1221, Apr. 2008 , Refereed
  • EEG analysis based on Independent Component Anlaysis and positive time-frequency distribution, N. Nakasako, H. Yoshida, N. Yamawaki, Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University, Memoirs of the Faculty of Biology-Oriented Science and Technology of Kinki University, (19), 23 - 35, Apr. 2007 , Refereed
  • Evaluation of Emotions for Music Sounds with Different Tones Based on Emotional Spectrum Analysis Method Using Brain Waves, 29, 1 - 8, Dec. 2005
  • A Practical Countermeasure to Wind-induced Noise in Environmental Noise Measurement Based on Linear and/or Non-linear Model Using Wind Speed Information, Noboru Nakasako, Koichi Sakamoto, Hitoshi Itoh, Yoshiaki Takakuwa, Memories of the School of Biology-oriented Science and Technology of Kinki University, Memories of the School of Biology-oriented Science and Technology of Kinki University, (16), 19 - 28, Oct. 2005 , Refereed
  • A consideration on sound reduction property in one-dimensional duct, N. Nakasako, H. Ogura, A. Ishikawa, Acoust. Sci. & Tech., Acoust. Sci. & Tech., 26(4), 374 - 415, Jul. 2005 , Refereed
  • Fundamental study on sound source localization and restoration Introduction of blind source separation and inverse filtering(Invited paper), N.Nakasako, H. Ogura, Y. Sakuma, Proc. 32nd International Congress and Exposition on Noise Control Engineering, Proc. 32nd International Congress and Exposition on Noise Control Engineering, 1478 - 1485, Aug. 2003
  • Fundamentals of independent component analysis(ICA)and acoustic signal processing, Noboru NAKASAKO, Hisanao OGURA, SYSTEMS, CONTROL AND INFORMATION, SYSTEMS, CONTROL AND INFORMATION, 46(7), 400 - 408, Jul. 2002
  • Simplified determination for the order of series type probability expression under introducing tolerance range and its application to traffic noise, N. Nakasako, M. Ohta, Acoust. Sci. & Tech.(旧日本音響学会英文誌), Acoust. Sci. & Tech.(旧日本音響学会英文誌), 22(5), 358 - 362, Sep. 2001 , Refereed
  • A fundamental consideration on the stochastic blind signal separation based on the rotational transformation and a measure of statistical independency, N. Nakasako, H. Ogura, M. Ohta, J. Acoust. Soc. Jpn. (E), J. Acoust. Soc. Jpn. (E), 21(1), 49 - 52, Jan. 2000 , Refereed
  • A practical and probabilistic evaluation method of sound insulation systems based on the extended regression analysis for roughly observed data, N. Nakasako, Y. Mitani, M, J. Acoust. Soc. Jpn. (E), J. Acoust. Soc. Jpn. (E), 19(6), 391 - 396, Nov. 1998 , Refereed
  • Identification and probabilistic response prediction methods of actual sound insulation systems contaminated by unknown background noise, N. Nakasako, M. Ohta, J. Acoust. Soc. Jpn. (E), J. Acoust. Soc. Jpn. (E), 19(2), 113 - 120, Mar. 1998 , Refereed
  • A probabilistic evaluation method of output response based on the extended regression analysis method for sound insulation systems with roughly observed data, N. Nakasako, M. 0hta, Y. Mitani, IEICE Trans. Fundamentals, IEICE Trans. Fundamentals, E80-A(10), 1410 - 1416, Oct. 1997 , Refereed
  • A precise estimation method of probability distribution based on roughly observed data with quantized level and its application to environmental sound noise measurement, Y. Mitani, N. Nakasako, J. Acoust. Soc.Jpn. (E), J. Acoust. Soc.Jpn. (E), 18(4), 183 - 190, Jul. 1997 , Refereed
  • A digital filter of restoring the stochastic signal from noisy and quntized observations, Noboru NAKASAKO, Mitsuo OHTA, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J79-A(5), 1013 - 1021, May 1996 , Refereed
  • A practical method of predicting Leq by use of Lx data for road traffic noise based on the introduction of probabilistic neura1networks, N. Nakasako, J. Acoust. S㏄. Jpn.(E), J. Acoust. S㏄. Jpn.(E), 17(1), 27 - 32, Jan. 1996 , Refereed
  • An extended evaluation method of non-Gaussian type sound envirenment utilizing the generalized capability in the parallel information processing of neural network and fuzzy probability, hta, A. Ikuta, N. Nakasako, 51(4), 299 - 306, Apr. 1995 , Refereed
  • The transformation relationship of dual direction type among noise evaluation indices L_x's based on an improvement of the principal component analysis method, Mitsuo Ohta, Noboru Nakasako, Yasuo Mitani, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 50(10), 829 - 835, Oct. 1994 , Refereed
  • A pratical regression analysis method based on the information criterion and its application to the actual acoustic system, Yasuo Mitani, Mitsuo Ohta, Noboru Nakasako, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 50(5), 353 - 360, May 1994 , Refereed
  • Generalization of Rician distribution for speckle pattern in ultra-sound image processing and random flights problem in Shannon's signal space, M. 0hta, S. Miyata, N. Nakasako, J. Acoust. Soc. Jpn(E), J. Acoust. Soc. Jpn(E), 13(2), 101 - 113, Mar. 1992 , Refereed
  • A study on the reverberation process from a view-point of the temporal transition of probability distribution information : An establishment of theory and its experiment, Mitsuo Ohta, Noboru Nakasako, Kazutatsu Hatakeyama, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 47(9), 639 - 646, Sep. 1991 , Refereed
  • New methodological trials of evaluating the sound intensity fluctuations at three observation points with arbitrary correlation in a diffuse sound fie1d, M. 0hta, N. Nakasako, K. Hatakeyama, ACUSTICA, ACUSTICA, 74(4), 242 - 253, Sep. 1991 , Refereed
  • Various stochastic properties of correlative fluctuation at arbitrary K observation points in a diffuse sound field : Establishment of theory and experiment, Mitsuo Ohta, Noboru Nakasako, Yasu Sato, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 47(8), 545 - 553, Aug. 1991 , Refereed
  • A stochastic evaluation method for the arbitary memory-type acoustic system with a non-linear observation and its application to the room acoustics-Continued report, Mitsuo Ohta, Noboru Nakasako, Kazumasa Nakamura, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 47(1), 13 - 20, Jan. 1991 , Refereed
  • Unification of various type expressions for probability distribution of arbitrary random noise and vibration waves based on their fluctuation ranges (theory and experiment), M. 0hta, N. Nakasako, Y. Xiao, Archives of Acoustics, Archives of Acoustics, 15(3-4), 399 - 416, Apr. 1990 , Refereed
  • The relation between mutual correlation and probability distribution for sound intensity fluctuations at two observation points in a diffuse sound field : Two methods of evaluating their correlation, Mitsuo Ohta, Noboru Nakasako, Kazumasa Nakamura, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 45(4), 255 - 262, Apr. 1989 , Refereed
  • A background noise correction method based on the dynamical state estimation algorithm for the actually observed data with arbitrary amplitude constraint, N. Nakasako, M, hta, B, Soenarko, Singapore Journal of Physics, Singapore Journal of Physics, 6(1), 137 - 144, Apr. 1989 , Refereed
  • Spatilal coorelation and probabilistic evaluation of fluctuations at two observation points in a diffuse sound field, Mitsuo OHTA, Noboru NAKASAKO, IEICE Trans. Fundamentals(Japanese Edition), IEICE Trans. Fundamentals(Japanese Edition), J71-A(11), 1999 - 2008, Nov. 1988 , Refereed
  • Several Type Practical Methods for Evaluating a Spatial Correlation of Sound Intensity Fluctuations in a Diffuse Sound Field, Mitsuo Ohta, Naomitsu Takaki, Noboru Nakasako, The Jounal of the INCE (Institute of Noise Control Engineers) of Japan, The Jounal of the INCE (Institute of Noise Control Engineers) of Japan, 12(1), 35 - 40, Feb. 1988 , Refereed
  • An identification method for arbitrary sound insulation walls under the background noise and the prediction of output probability : A practical algorithm based on a time series model, Mitsuo Ohta, Akira Ikuta, Noboru Nakasako, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 43(11), 837 - 844, Nov. 1987 , Refereed
  • Two probabilistic evaluation methods for single and double wall type sound insulation systems with arbitrary random noise excitation, M.0hta, N.Nakasako, The Journal of the Acoustical Society of Japan(E), The Journal of the Acoustical Society of Japan(E), 7(6), 335 - 342, Nov. 1986 , Refereed
  • A dynamical state estimation method based on the non-linear mixed stochastic model in room acoustics, M. Ohta, N. Nakasako, K. Hatakeyama, ACUSTICA, ACUSTICA, 62(2), 123 - 130, Nov. 1986 , Refereed
  • An evaluation theory of nonstationarity for the stochastic noise or vibration based on a temporal change of mean and variance and its application to the road traffic noise, Mitsuo OHTA, Noboru NAKASAKO, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 42(2), 102 - 112, Feb. 1986 , Refereed
  • A simplified evaluation method for nonstationary Gaussian random process, N. Nakasako, Acoustics Letter, Acoustics Letter, 12(8), 199 - 202, Aug. 1985 , Refereed
  • A probabilistic theory for the non-linear evaluation of arbitrary mixed model type acoustic systems and a probablistic evaluation of fluctuating Leq, Mitsuo Ohta, Hiroshi Yamada, Noboru Nakasako, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 41(4), 221 - 229, Apr. 1985 , Refereed
  • A practical probabilistic evaluation method for actually complicated insulation systems based on linear and non-linear regression models between observed input and output data of the system, M. Ohta, N. Nakasako, The Journal of the Acoustical Society of Japan(E), The Journal of the Acoustical Society of Japan(E), 6(2), 127 - 134, Apr. 1985 , Refereed
  • An identification and probabilistic prediction of arbitrary stochastic acoustic systems based on the regression model, Mitsuo OHTA, Noboru NAKASAKO, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 41(1), 13 - 20, Jan. 1985 , Refereed
  • A statistical evaluation method on the acuity of wave form for random noise and vibration : Level crossing,peak and trough, Mitsuo Ohta, shoji Oki, Noboru Nakasako, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN, 40(2), 87 - 94, Feb. 1984 , Refereed
  • A new trial of estimating the equivalent characteristic of sound propagation for the actual road traffic noise field based on the mixing model of two idealized propagation environments, M Ohta, A. Ikuta, N. Nakasako, The Journal of the Acoustical Society of Japan(E), The Journal of the Acoustical Society of Japan(E), 4(4), 189 - 202, Aug. 1983 , Refereed
  • A Study on Acoustic Beam Steering with Parametric Loudspeaker Based on Individual Delay-filtering for Carrier and Sideband Waves, Masato Nakayama, Takanobu Nishiura, Ryota Okuno, Noboru Nakasako, 2014 IEEE ASIA PACIFIC CONFERENCE ON CIRCUITS AND SYSTEMS (APCCAS), 2014 IEEE ASIA PACIFIC CONFERENCE ON CIRCUITS AND SYSTEMS (APCCAS), 447 - 450, 2014 , Refereed
    Summary:Parametric loudspeaker can form an acoustic beam with sharper directivity by using multiple small ultrasonic transducers. In recent years, acoustic beam steering methods based on delay-processing for multiple small ultrasonic transducers is proposed. However, in these methods, spatial aliasing in ultrasonic waves has not been focused. Therefore, in this paper, we investigate the relationship between the spatial aliasing of ultrasonic waves and the acoustic beam of audible sounds. In addition, we propose acoustic beam steering with parametric loudspeaker by individual delay-filtering for carrier and sideband waves.
  • A Prototype of BCI-Robot Arm System with 1ch Acoustic Distance Measurement Device, Nobuyuki Yamawaki, Noboru Nakasako, Tatuya Nishimae, Toshihiro Shinohara, Masato Nakayama, Daichi Yoshida, 2013 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATIONS SYSTEMS (ISPACS), 2013 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATIONS SYSTEMS (ISPACS), 336 - 339, 2013 , Refereed
    Summary:Patients who have difficulty moving their muscles freely require support for various situations that occur in everyday life. A controllable robot arm without using muscles may make the patient's quality of life improve. By using a brain-computer interface (BCI), control of the robot arm is possible by thought alone. Therefore, we have constructed several robot arms with an ultrasonic range finder and a web camera for BCI system. By utilizing these devices, collisions between the robot arm and the user could be avoided and control could be partially automated. The distance is very important information in the system. In the present work, an acoustic distance measurement (ADM) device was used. It consists of equipment with easy acquisition and does not need an electronic circuit which is in the ultrasonic range finder. It is a new device and has a possibility of simplifying the ADM device.
  • Fundamental Consideration on 1ch Acoustic Distance Measurement Method Based on Phase Interference by Considering the Movement of Transmitting-and-Receiving System, Noboru Nakasako, Tatuya Nishimae, Toshihiro Shinohara, Nobuyuki Yamawaki, Masato Nakayama, Tetsuji Uebo, 2013 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATIONS SYSTEMS (ISPACS), 2013 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATIONS SYSTEMS (ISPACS), 332 - 335, 2013 , Refereed
    Summary:Since the distance to target is very important information, we have proposed an acoustic distance measurement (ADM) method using a standing wave, which is generated by interference between transmitted and reflected waves. However, the amplitude-frequency characteristics of the measuring system between the microphone and the loudspeaker are not considered, but these characteristics cannot be ignored in a real environment. To remove the effect of the measuring system, our previous methods required a 2ch microphone or two measurements with targets and without targets. This paper describes a new ADM method considering a movement of transmitting-and-receiving system composed of 1ch microphone and loudspeaker. Finally, we examine the validity and effectiveness of our method by applying it to an actual sound field.
  • ACOUSTIC DISTANCE MEASUREMENT BASED ON PHASE INTERFERENCE USING THE CROSS-SPECTRAL METHOD WITH ADJACENT MICROPHONES, Masato Nakayama, Kazuhiro Suzuki, Noboru Nakasako, 2013 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP), 2013 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP), 423 - 427, 2013 , Refereed
    Summary:In a number of engineering fields, information on the distance to the target is very important. We previously proposed an acoustic distance measurement method based on interference between the transmitted and reflected waves, which can be used for distance measurement over a short range. In the previously proposed method, a sound source of the transmitted wave must be known in advance. In the present paper, we propose a new acoustic distance measurement method based on phase interference obtained using the cross-spectral method with adjacent microphones, which does not require the condition that a sound source of the transmitted wave is known. Finally, we confirmed the validity and effectiveness of the newly proposed method through both computer simulation and evaluation experiment in a real environment.
  • Acoustic Distance Measurement Method Based on Phase Interference Using Calibration and Whitening Processing in Real Environments, Masato Nakayama, Shimpei Hanabusa, Tetsuji Uebo, Noboru Nakasako, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E94A(8), 1638 - 1646, Aug. 2011 , Refereed
    Summary:Distance to target is fundamental and very important information in numerous engineering fields. Many distance measurement methods using sound use the time delay of a reflected wave, which is measured in reference to the transmitted wave. This method, however, cannot measure short distances because the transmitted wave, which has not attenuated sufficiently by the time the reflected waves are received, suppresses the reflected waves for short distances. Therefore, we proposed an acoustic distance measurement method based on the interference between the transmitted wave and the reflected waves, which can measure distance in a short range. The proposed method requires a cancellation processing for background components due to the spectrum of the transmitted wave and the transfer function of the measurement system in real environments. We refer to this processing as background components cancellation processing (BGCCP). We proposed BGCCP based on subtraction or whitening. However, the proposed method had a limitation with respect to the transmitted wave or additive noise in real environments. In the present paper, we propose an acoustic distance measurement method based on the new BGCCP. In the new BGCCP, we use the calibration of a real measurement system and the whitening processing of the transmitted wave and introduce the concept of the cepstrum to the proposed method in order to achieve robustness. Although the conventional BGCCP requires the recording of the transmitted wave under the condition without targets, the new BGCCP does not have this requirement. Finally, we confirmed the effectiveness of the proposed method through experiments in real environments. As a result, the proposed method was confirmed to be valid and effective, even in noisy environments.
  • A fundamental study on the statistical evaluation of receiver response for an electromagnetic wave environment in multi-dimensional signal space - Theory and basic experiment, M Ohta, Y Mitani, N Nakasako, JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, 12(5), 677 - 699, 1998 , Refereed
    Summary:In this paper, a statistical electromagnetic (abbr., EM) interference study is constructed mainly from a theoretical viewpoint on the basis of N-dimensional random walk problem in multi-dimensional signal space. First, a characteristic function of the Hankel transform type matched to this EM environmental study is introduced especially in an extended form of D. Middleton's basic result. Then, the probability density function (abbr., pdf) is explicitly derived for the EM random fluctuation with a power scaled variable (or an effective value) measured by a receiver with a mean square operation. The proposed theory is verified by showing the agreement with one of D. Middleton's great researches as a special case of the proposed expressions. Moreover, the effectiveness of the proposed method is experimentally confirmed through an acoustic type simulation of EM environment and the application to a simplified actual EM environment with joint space-time non-Poisson interference as one of the same wave motion type environment as EM environment.
  • A prediction method of non-stationary time series data by using a modular structured neural network, E Watanabe, N Nakasako, Y Mitani, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E80A(6), 971 - 976, Jun. 1997 , Refereed
    Summary:This paper proposes a prediction method for non-stationary time series data with time varying parameters. A modular structured type neural network is newly introduced for the purpose of grasping the changing property of time varying parameters. This modular structured neural network is constructed by the hierarchical combination of each neural network (NNT: Neural Network for Prediction of Time Series Data) and a neural network (NNW: Neural Network for Prediction of Weights). Next, we propose a reasonable method for determination of the length of the local stationary section by using the additive learning ability of neural networks. Finally, the validity and effectiveness of the proposed method are confirmed through simulation and actual experiments.
  • A state estimation method in acoustic environment based on fuzzy observation contaminated by background noise - Utilization of inverse probability and digital filter, A Ikuta, M Ohta, N Nakasako, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E80A(5), 825 - 832, May 1997 , Refereed
    Summary:In the measurement of actual random phenomenon, the observed data often contain the fuzziness due to the existence of confidence limitation in measuring instruments, permissible error in experimental data, some practical simplification of evaluation procedure and a quantized error in digitized observation. In this study, by introducing the well-known fuzzy theory, a state estimation method based on the above fuzzy observations is theoretically proposed through an establishment of wide sense digital filter under the actual situation of existence of the background noise in close connection of the inverse problem. The validity and effectiveness of the proposed method are experimentally confirmed by applying it to the actual fuzzy data observed in an acoustic environment.
  • A probabilistic evaluation method of discriminating system characteristics from background noise by use of multi-output observations in a complicated sound environment, N Nakasako, M Ohta, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E79A(8), 1252 - 1255, Aug. 1996 , Refereed
    Summary:This paper describes a trial of evaluating the proper characteristics of multiple sound insulation systems from their output responses contaminated by unknown background noises, The unknown parameters of sound insulation systems are first estimated on the basis of the linear time series on an intensity scale, describing functionally the input-output relation of the systems. Then, their output probability distributions are predicted when an arbitrary input noise passes through these insulation systems.
  • STOCHASTIC SIGNAL-DETECTION FROM A SATURATED NOISY OBSERVATION AND ITS APPLICATION TO ROOM ACOUSTICS, M OHTA, N NAKASAKO, JOURNAL OF SOUND AND VIBRATION, JOURNAL OF SOUND AND VIBRATION, 176(2), 209 - 224, Sep. 1994 , Refereed
    Summary:In the measurement of actual phenomena, the observed data often suffer from loss or distortion due to the limited dynamic range of the measurement instruments. This paper describes a new method of dynamical state estimation for stochastic systems, in a practical case in which the observed data fluctuates within a finite amplitude domain owing to the dynamic range of the measurement instrument. The state estimation method proposed for use with such incomplete observation data (with information loss or distortion) is a theoretically based improvement of the wide sense digital filter, for situations in which the data is contaminated by an external noise of arbitrary distribution type. A recurrence type estimation algorithm is explicitly derived in series expansion form from the Bayesian viewpoint, with the aim of utilizing hierarchically the linear and non-linear correlation information between the observed value and the unknown state variable. The proposed estimation theory is experimentally confirmed by applying it to a problem of background noise correction in room acoustics.
  • STOCHASTIC SIGNAL-PROCESSING FOR INCOMPLETE OBSERVATIONS UNDER THE AMPLITUDE LIMITATIONS IN INDOOR AND OUTDOOR SOUND ENVIRONMENTS BASED ON REGRESSION-ANALYSIS, N NAKASAKO, M OHTA, H OGAWA, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E77A(8), 1353 - 1362, Aug. 1994 , Refereed
    Summary:A specific signal in most of actual environmental systems fluctuates complicatedly in a non-Gaussian distribution form, owing to various kinds of factors. The nonlinearity of the system makes it more difficult to evaluate the objective system from the viewpoint of internal physical mechanism. Furthermore, it is very often that the reliable observation value can be obtained only within a definite domain of fluctuating amplitude, because many of measuring equipment have their proper dynamic range and the original random wave form is unreliable at the end of amplitude fluctuation. It becomes very important to establish a new signal processing or an evaluation method applicable to such an actually complicated system even from a functional viewpoint. This paper describes a new trial for the signal processing along the same line of the extended regression analysis based on the Bayes' theorem. This method enables us to estimate the response probability property of a complicated system in an actual situation, when observation values of the output response are saturated due to the dynamic range of measuring equipment. This method utilizes the series expansion form of the Bayes' theorem, which is applicable to the non-Gaussian property of the fluctuations and various kinds of correlation information between the input and output fluctuations. The proposed method is newly derived especially by paying our attention to the statistical information on the input-output data without the saturation operation instead of that on the resultantly saturated observation, differing from the well-known regression analysis and its improvement. Then, the output probability distribution for another kind of input is predicted by using the estimated regression relationship. Finally, the effectiveness of the proposed method is experimentally confirmed too by applying it to the actual data observed for indoor and outdoor sound environments.
  • A PRACTICAL TRIAL OF DYNAMICAL STATE ESTIMATION FOR NON-GAUSSIAN RANDOM VARIABLE WITH AMPLITUDE LIMITATION AND ITS APPLICATION TO THE REVERBERATION TIME MEASUREMENT, N NAKASAKO, M OHTA, Y MITANI, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E76A(9), 1392 - 1402, Sep. 1993 , Refereed
    Summary:Most of actual environmental systems show a complicated fluctuation pattern of non-Gaussian type, owing to various kinds of factors. In the actual measurement, the fluctuation of random signal is usually contaminated by an external noise. Furthermore, it is very often that the reliable observation value can be obtained only within a definite fluctuating amplitude domain, because many of measuring equipments have their proper dynamic range and original random wave form is unreliable at the end of amplitude fluctuation. It becomes very important to establish a new signal detection method applicable to such an actual situation. This paper newly describes a dynamical state estimation algorithm for a successive observation contaminated by the external noise of an arbitrary distribution type, when the observation value is measured through a finite dynamic range of measurement. On the basis of the Bayes' theorem, this method is derived in the form of a wide sense digital filter, which is applicable to the non-Gaussian properties of the fluctuations, the actual observation in a finite amplitude domain and the existence of external noise. Differing from the well-known Kalman's filter and its improvement, the proposed state estimation method is newly derived especially by paying our attention to the statistical information on the observation value behind the saturation function instead of that on the resultant noisy observation. Finally, the proposed method is experimentally confirmed too by applying it to the actual problem for a reverberation time measurement from saturated noisy observations in room acoustics
  • DISCRETE-TIME MODELING AND DIGITAL SIGNAL-PROCESSING FOR A PARAMETER-ESTIMATION OF ROOM ACOUSTIC SYSTEMS WITH NOISY STOCHASTIC INPUT, M OHTA, N NAKASAKO, K HATAKEYAMA, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E75A(11), 1460 - 1467, Nov. 1992 , Refereed
    Summary:This paper describes a new trial of dynamical parameter estimation for the actual room acoustic system, in a practical case when the input excitation is polluted by a background noise in contrast with the usual case when the output observation is polluted. The room acoustic system is first formulated as a discrete time model, by taking into consideration the original standpoint defining the system parameter and the existence of the background noise polluting the input excitation. Then, the recurrence estimation algorithm on a reverberation time of room is dynamically derived from Bayesian viewpoint (based on the statistical information of background noise and instantaneously observed data), which is applicable to the actual situation with the non-Gaussian type sound fluctuation, the non-linear observation, and the input background noise. Finally, the theoretical result is experimentally confirmed by applying it to the actual estimation problem of a reverberation time.
  • THE RANDOM-WALK PROBLEM IN N-DIMENSIONAL SIGNAL SPACE AND STOCHASTIC ACOUSTIC INFORMATION-PROCESSING - INTRODUCTION OF A HANKEL TRANSFORM TYPE OF CHARACTERISTIC FUNCTION AND ROOM ACOUSTICS, M OHTA, N NAKASAKO, ACUSTICA, ACUSTICA, 74(1), 23 - 40, Jun. 1991 , Refereed
    Summary:This paper, which is dedicated to Dr. M. Jessel in celebration of his 70th birthday, gives an exact expression for the stochastic problem of N-dimensional random walks on the basis of information theory in close connection with room acoustics. The probability density function is derived for the sum of independent and isotropic random vectors in an N-dimensional signal space, when the magnitude is independent of the direction. First, a characteristics function of the Hankel transform type is newly introduced, because it is suitable for consideration of the probability problem of N-dimensional random walks, and can be used to derive an exact representation of the probability density function. Then, the probability density function is explicitly derived for the random fluctuation of a power scaled variable (or effective value) with a mean squaring function (for instance, the sound or vibration energy fluctuation observed via a sound level meter or sound vibration meter). Finally, the validity and effectiveness of the proposed theory is experimentally confirmed by the use of a digital simulation technique, and is discussed particularly in connection with room acoustics.
  • AN EVALUATION THEORY FOR A MIXED MODEL STOCHASTIC-SYSTEM AND ITS APPLICATION TO NONSTATIONARY ROAD TRAFFIC NOISE, M OHTA, N NAKASAKO, ACUSTICA, ACUSTICA, 71(2), 121 - 126, Jun. 1990 , Refereed
  • NEW METHODOLOGICAL TRIALS OF ESTIMATING THE SOUND POWER LEVEL IN A ROOM BASED ON STOCHASTIC INFORMATION-PROCESSING, M OHTA, N NAKASAKO, K KITOH, ACUSTICA, ACUSTICA, 70(4), 292 - 296, Apr. 1990 , Refereed
  • A DYNAMICAL IDENTIFICATION METHOD BASED ON CONDITIONED OBSERVATIONS FOR A SOUND INSULATION SYSTEM WITH THE ORDER DETERMINED BY A NEW CRITERION INDEX, M OHTA, K HATAKEYAMA, A IKUTA, JOURNAL OF SOUND AND VIBRATION, JOURNAL OF SOUND AND VIBRATION, 127(2), 253 - 270, Dec. 1988 , Refereed
  • THE PROBABILISTIC EVALUATION OF DISCRETE LEVEL TYPE FOR A SOUND-TRANSMISSION THROUGH THE DOUBLE-WALL BY USE OF A STATISTICAL ENERGY ANALYSIS METHOD, M OHTA, H IWASHIGE, N NAKASAKO, ACUSTICA, ACUSTICA, 64(1), 1 - 13, Jul. 1987 , Refereed
  • A STOCHASTIC-THEORY ON THE BACKGROUND-NOISE CORRECTION CONSIDERED AS AN EQUIVALENT NONLINEAR FEEDBACK-SYSTEM WITH DIGITIZED LEVEL OBSERVATIONS AND ITS EXPERIMENTS, M OHTA, Y FUJITA, N NAKASAKO, B ZHANG, ACUSTICA, ACUSTICA, 63(3), 191 - 202, May 1987 , Refereed
  • A PREDICTION METHOD OF THE RESPONSE PROBABILITY-DISTRIBUTION FOR ARBITRARY SOUND INSULATION SYSTEMS, N NAKASAKO, M OHTA, S KUWAHARA, APPLIED ACOUSTICS, APPLIED ACOUSTICS, 22(2), 103 - 115, 1987 , Refereed
  • A NEW EVALUATION METHOD ON THE SOUND-TRANSMISSION LOSS OF GENERAL N-FOLD WALL BY USE OF A MODIFIED STATISTICAL ENERGY ANALYSIS METHOD, M OHTA, H IWASHIGE, N NAKASAKO, ACUSTICA, ACUSTICA, 61(2), 105 - 115, Aug. 1986 , Refereed
  • A NEW METHODOLOGICAL TRIAL ON PROBABILISTIC PREDICTION OF ROAD TRAFFIC NOISE BASED ON THE GROUPING MODEL OF POISSON-TYPE TRAFFIC-FLOW, M OHTA, K NAKAMURA, N NAKASAKO, ACUSTICA, ACUSTICA, 58(1), 39 - 47, 1985 , Refereed
  • A TRIAL OF PROBABILISTIC EVALUATION FOR THE SOUND INSULATION SYSTEM BASED ON THE MODIFIED METHOD OF STATISTICAL ENERGY ANALYSIS, M OHTA, S YAMAGUCHI, N NAKASAKO, ACUSTICA, ACUSTICA, 56(4), 270 - 279, 1984 , Refereed

Books etc

  • Higher-order Statistical Signal Pocessing, E. Uchino, M. 0hta, H. Minamihara, N. Nakasako, B, Boashash, E. J. Powers, A. M. Zoubir, 分担執筆, Chap. 5, pp.151-177, Longman, Melbourne,   1995 07
  • IEICE Dictionary of Electronics, Information and Communication Terms,   1999
  • Encyclopedia Electronics, Information and Communication Handbook,   1998
  • Higher-Order Statistical Signal Processing (jointly worked)(Edited by B.Boashash,E.J.Powers&A.M.Zoubin), Longman,Wiley,   1995

Conference Activities & Talks

  • Distance Measurementby Independent Component Analysis and Autocorrelation FunctionUsing Adjacent 2ch Microphones under High Noise, Noboru Nakasako, Yusuke Nakaoka, Toshihiro Shinohara, Tetsuji Uebo,   2020 05 20
  • Distance measurement and its implementation for very close range using both power and phase spectra of observation sound, NAKASAKO Noboru,   2019 08 29
  • Estimation of distance and velocity of moving targets based on phase interference using observed signals by two adjacent microphones, N. Nakasako, N. Yamazaki, H. Nakagawa, T. Shinohara, T. Uebo,   2019 05 22
  • Distance measurement based on the phase interference using adjacent 2 ch microphones under highly noisy environment (A trial of noise countermeasure by semi-blind signal processing), N. Nakasako, S. Murata, T. Shinohara, T. Uebo,   2018 05 16
  • A noise countermeasure for acoustic distance method based on phase interference in actual sound field using Normalized Least Mean Square (NLMS) method (Estimation of distance and velocity for a target moving with constant velocity), Natsuki Yamazaki, Toshihiro Shinohara, Tetsuji Uebo, Noboru Nakasako,   2017 09 01
  • Development of software to improve a basic communication skill by using voice and image processing, Ryohei Oda, Toshihiro Shinohara, Noboru Nakasako,   2017 09 01
  • A Consideration of Distance Resolution in Distance Measurement Method Based on Phase Interference Using Ultrasound, Toshihiro Shinohara, Tomohiro Ito, Tetsuji Uebo, Noboru Nakasako,   2017 08 31
  • Estimation of distance and velocity for a moving target with constant velocity using acoustic distance measurement method based on phase interference, Noboru Nakasako, Natsuki Yamazaki, Toshihiro Shinohara, Tetsuji Uebo, The 61st Annual Conference of the Institute of Systems, Control and Information Engineers,   2017 05 25
  • A trial of acoustical distance measurement based on phase interference using phase-steering at each channel of parametric loudspeaker to measure the distance to a human, T. Nakano, T. Shinohara, T. Uebo, M. Nakayama, N. Nakasako,   2016 09 01
  • 位相干渉と直流成 分の除去に基づく0mから計測可能な2ch音響測距法, 鈴木 和博, 中迫 昇, 中山 雅人, 篠原 寿広, 上保 徹志, 平成26年度電気関係学 会関西連合大会講演論文集,   2014 11
  • 解析信号の導入に よる超近距離計測可能な位相干渉に基づく2ch 音響測距法の検討, 鈴木 和博, 中迫 昇, 中山 雅人, 篠原 寿広, 上保 徹志, 2014年秋季 研究発表会講演論文集,   2014 09
  • Effect of the additional noise and the noise reduction method for the acoustic distance measurement method based on phase interference using cross spectrum in a noisy environment, SUZUKI Kazuhiro,   2014 03 10
  • A trial on calculating the equivalent reflection coefficient by acoustic distance measurement method based on phase interference in actual field, NEKI Yuma,   2014 03 10
  • A study on superimposition mode of mastication EMG on EEG, and its trial separation on FDICA,   2013 12
  • A study on EEG lead systems, artifacts mixed into the EEGs when eating, and their classification methods based on ICA,   2013 09
  • A Study of Visualization system of Three-dimensional Image for Diagnostic Assistance of Cerebrovascular Diseases with Head-mounted Display Considering Head Position of Operator,   2013 08
  • Fudndamental consideration on 1ch acoustic distance measurement method based on phase interference by considering the movement of transmitting and receiving system,   2013 05
  • A basic study to manipulate volume data of brain blood vessel using its position and diameter,   2013 01
  • Estimation of Center Line and Diameter of Blood Vessel by Vessel Tracing with Sequenctially Binarized Head CTA Image,   2013 01
  • Estimation of Centerline and Diameter of Brain Vessel in 3D Head CTA Image by Using Model Matching Method, International Forum on Medical Imaging in Asia,   2012 11 , International Forum on Medical Imaging in Asia
  • Extraction of the cerebral blood vessel from the head CTA image based on the Bayes' theorem using a blood vessel position, radius, and luminance distribution,   2012 08
  • A Simplified Estimation Method for Environmental Noises Using Independent Component Analysis, 19th International Congress on Sound and Vibration (Vilnius, Lithuania),   2012 07 , 19th International Congress on Sound and Vibration (Vilnius, Lithuania)
  • The vibration detection by time tracking the estimated distance specrum using the Acoustic Distance Measurement method with the cross spectral technique,   2012 05
  • A study of acoustic distance measurement method based on interference of speech presented by a dialogue system in real environments,   2012 05
  • Visualization of Cerebrovascular Structure Based on Position and Caliber of Blood Vessel,   2012 05
  • Estimation of Center Line and Diameter of Blood Vessel by Vessel Tracing with Simple Binarized Head CTA Image,   2012 01
  • A experimental study of acoustic distance measurement based on cross-spectral method using 2-channel microphones,   2012 01
  • Distance measurement method measurable from 0m based on power spectrum fluctuation of the interference sound for 1ch observations,   2011 11
  • A fundamental study of three-dimensional sound field reproduction based on the acoustic distance measurement method using parametric loudspeakers on the right and left sides,   2011 09
  • A study of the acoustic distance measurement method measurable from 0m based on phase of range spectrum,   2011 09
  • An experimental study of the effects of both reflection coefficient and distance decay in the acoustic distance measurement method based on interference,   2011 09
  • A fundamental study of the acoustic measurement method based on interference considering the movement of the loudspeaker and microphone,   2011 09
  • Estimation of distance from sound source using single microphone based on interference between transmitted and reflected waves, INTER-NOISE 2011, the 40th International Congress and Exposition on Noise Control Engineering,,   2011 09 , INTER-NOISE 2011, the 40th International Congress and Exposition on Noise Control Engineering,
  • Multiple-nulls-steering beamformer based on both talkers and noises localization, INTER-NOISE 2011, the 40th International Congress and Exposition on Noise Control Engineering,   2011 09 , INTER-NOISE 2011, the 40th International Congress and Exposition on Noise Control Engineering
  • Development the three-dimensional pointing device by single camera using ARToolKit to support the brain blood vessel disease diagnosis,   2011 08
  • A fundamental study of multiple-nulls-steering beamformer based on both talkers and noises localization,   2011 05
  • A study of robot sensor system by using speech for information presentation,   2011 05
  • Consideration on the effect of frequency-amplitude characteristics of the transmitted sound and measuring system on distance estimation method based on phase interference and trial to remove the effect,   2011 03
  • Acoustic tracking method based on interference for a moving object - a fundamental study with linear chirp signal -,   2011 03
  • A study of acoustic distance measurement method based on phase interference of computer-emitted speech using phoneme segmentation,   2011 03
  • A study of object localization based on a two-channel acoustic distance measurement method using a transmitted sound with high frequency components,   2011 03
  • Acoustic distance measurement method based on phase interference using linear chirp signal ―A trail on tracking of a moving object―,   2011 01
  • Distance estimation based on interference between transmitted and reflected audible sound in actual environment ( some trials on removing the effect of frequency-amplitude characteristics of the transmitted sound and measuring system and their comparativ,   2010 11
  • Robust Acoustic Distance Measurement Method Based on Interference in Noisy Environments, The 2010 International Symposium on Communications and Information Technologies (ISCIT2010),   2010 10 , The 2010 International Symposium on Communications and Information Technologies (ISCIT2010)
  • Distance Estimation Method Measurable from 0m Based on Standing Wave Using Band-limited Sound with Uniform Amplitude and Random Phase, The 2010 International Symposium on Communications and Information Technologies (ISCIT2010),   2010 10 , The 2010 International Symposium on Communications and Information Technologies (ISCIT2010)
  • Estimation of Center Line and Diameter of Blood Vessel in Three-dimensional Head CTA by Vessel Tracing with Three-dimensional Blood Vessel Matching Method,   2010 09
  • Three-dimensional sound field reproduction method based on acoustic distance measurement using near loudspeakers -- a study of a sound quality and its correction method--,   2010 09
  • A study of acoustic distance measurement method based on interference by using subtraction of known signals,   2010 09
  • A fundamental study of acoustic distance measurement method based on interference of a transmitted wave having a time width to a moving object,   2010 09
  • A consideration on 2-channel acoustic distance estimation method measurable from 0m based on phase interference,   2010 09
  • A study of talker localization method by combining a two-channel acoustic distance measurement method and a CSP method,   2010 09
  • Estimation of Center Line and Diameter of Brain Blood Vessel Using Three-dimensional Blood Vessel Matching Method with Head Three-dimensional CTA,   2010 08
  • Fundamental study on distance estimation using audible sound for aiming to analyze an ability of reading a sign of surrounding objects,   2010 05
  • A study of three dimensional sound field reproduction based on distance estimation using near loudspeaker on the right and left sides,   2010 05
  • A trial of distance estimation to a subject with speech (based on standing wave theory),   2010 03
  • A study of distance estimation based on interference of audible sound for a moving object,   2010 03
  • Estimation of distance from sound source using single microphone based on interference between transmitted and reflected audible sound (utilization of duplicative reflection),   2010 03
  • Distance estimation method measurable from 0m using a standing wave of audible sound -- Utilization of band-limited Gaussian noise --,   2010 01
  • Distance estimation based on interference between transmitted and reflected audible sound---a trial on removing the effect of frequency-amplitude characteristics of the transmitted sound and measuring system---,   2009 11
  • Correction Method of Estimated Distance Using Geometrical Information on Sound Source and Microphone, 2009 Asia-Pacific Signal and Information Processing Association, Annual Summit and Conference,   2009 10 , 2009 Asia-Pacific Signal and Information Processing Association, Annual Summit and Conference
  • Fundamental consideration on distance estimation based on interference between transmitted and reflected waves using audible sound (Removal of the frequency-amplitude characteristic of measuring system),   2009 09
  • Distance estimation based on the standing wave thoery under white noise input (Reduction of the number of experiments due to the removal of frequency-amplitude characteristics of the transmitted sound and measuring system),   2009 09
  • Distance Estimation and Compensation Method Using Band-limited Transmitted Wave with Uniform Amplitude and Random Phase Characteristics, The 24th International Technical Conference on Circuits/Systems, Computers and Communications,   2009 07 , The 24th International Technical Conference on Circuits/Systems, Computers and Communications
  • Distance estimation based on acoustical standing wave using audible transmitted wave and its compensation method,   2009 05
  • A study of talker localization based on distance estimation using the standing wave and microphone array,   2009 03
  • Fundamental consideration of distance estimation based on interference between transmitted and reflected waves using audible sound (Compensation by geometric arrangement of sound source and microphone),   2009 03
  • A consideration on distance estimation based on the standing wave and its implementation (utilization of chirp sound signal),   2009 01
  • Consideration on distance estimation using interference between transmitted and reflected sound ---Utilization of band-limited Gaussian noise---,   2008 11
  • Distance estimation method between microphone and targets using band-limited random noise and its statistical property,   2008 10
  • Fundamental consideration on estimation of distance from microphone to object with audible sound based on standing wave theory (Geometrical positions of sound source, microphone and object),   2008 09
  • Distance estimation between microphone and target based on phase interference using a transmitted signal of band-limited gaussian noise,   2008 09
  • Distance estiomation based on periodicity of power spectrum induced by interference between transmitted and reflected sound,   2008 05
  • Distance measurement with audible chirp signal based on standing wave,   2008 03
  • Experimental consideration on distance estimation using interference of transmitted wave and reflected wave (validity ofdistance estimatiion and estimation of reflection coefficients),   2008 03
  • Distance estimation to targets using white gaussian noise signal,   2008 03
  • A trial on the implimentation for distance estimation method based on standing waves of audible sound,   2008 01
  • Distance estimation based on standing wave theory with impuse aound -- experimental comparison with cepstrum analysis,   2007 11
  • Fundamental consideration on distance measurement by using band-limited random noise,   2007 11
  • Fundamental consideration on distance estimation based on interference between transmitted and reflected sound,   2007 11
  • Distance estimation based on standing wave of audible sound under a pulse input (Comparison with Cepstrum analysis),   2007 09
  • On distance measurement using band-limited noise, SICE Annual Conference 2007,   2007 09 , SICE Annual Conference 2007
  • Distance estimation to targets using band-limted signal,   2007 09
  • Distance estimation using standing wave with impusive sound,   2007 08
  • Distance measurement by audible sound (Utilization of band-limited signal with random phase), The China-Japan Joint Conference of Acoustics 2007 (JCA2007),   2007 06 , The China-Japan Joint Conference of Acoustics 2007 (JCA2007)
  • Simplified estimation method for environmental noises using Independent Component Analysis,   2007 05
  • Distance measurement to targets using audible sound (Possilbility of utilization of standing wave),   2007 05
  • Distance measurement by audible sound (Experimental consideration using band-limited noise),   2007 03
  • Distance estimation using standing wave for audible sound (Fundamenal experiment with impulse input),   2007 03
  • Sound reduction property of one-dimensional duct with random loadings, The 35th International Congress and Exposition on Noise Control Engineering (Inter-noise 2006),   2006 12 , The 35th International Congress and Exposition on Noise Control Engineering (Inter-noise 2006)
  • A simplified estimation method for environmental noises using Independent Component Analysis,   2006 11
  • A trial to song searchin system considerinag individual vocal range,   2006 11
  • A trial of analyzing an acoustic signal by time-frequency distrubution -- Introduction of Copula-based positive time-frequency distribution --,   2006 09
  • Fundamenal consideration on distance estimation using standing wave,   2006 09
  • Fundamental Consideration on Independent Component Analysis for 3-dimensional Complex Signals due to 3-dimensional Unitary Transformation --Maximization of Evaluation Function Based on Complex Hermite Moment--, 13th International Congress on Sound and Vibration (ICSV13),   2006 07 , 13th International Congress on Sound and Vibration (ICSV13)
  • Practical Prediction Method for Environmental Noises Using Neural Network Model, 9th Western Pacific Acoustic Conference (WESPAC IX),   2006 06 , 9th Western Pacific Acoustic Conference (WESPAC IX)
  • Simplified Estimation Method for Environmental Noises Using Independent Component Analysis, 9th Western Pacific Acoustic Conference (WESPAC IX),   2006 06 , 9th Western Pacific Acoustic Conference (WESPAC IX)
  • On the simulation for one-dimensional duct noise based on transmission-line model, 9th Western Pacific Acoustic Conference (WESPAC IX),   2006 06 , 9th Western Pacific Acoustic Conference (WESPAC IX)
  • Parameter estimation based on complex ICA for time-delayed mixture and signal separation/restoration by inverse filter,   2006 05
  • BLIND SOURCE SEPARATION FOR 3-DIMENSIONAL CONVOLUTIVE MIXTURE IN TERMS OF PARAMETERIZATION OF UNITARY MATRIX AND COMPLEX HERMITE MOMENT,   2006 03
  • A trial of analyzing an acoustic signal by Copula-based positive time-frequency distrubution -- Analysis method taking marginal distributions in time and frequency domains into consideration --,   2006 03
  • Fundamental Consideration on Independent Component Analysis for 3-dimensional Complex Signals due to 3-dimensional Unitary Transformation --Maximization of Evaluation Function Based on Complex Hermite Moment,   2006 01
  • A trial of analyzing an acoustic signal by time-frequency analysis --Introduction of Copula-based positive time-frequency distribution--,   2005 11
  • Sound Reduction Property of One-Demensional Duct with Random Loading,   2005 09
  • Blind separation of N-dimensional mixed signals in terms of Hermite moment and its application to EEG data, The 5th international Workshop on Biosignal Interpretation,   2005 09 , The 5th international Workshop on Biosignal Interpretation
  • Effect of Non-objective Component on the Estimation in Independent Component Analysis, 12th International Congress on Sound and Vibration (ICSV12),   2005 07 , 12th International Congress on Sound and Vibration (ICSV12)
  • SOUND REDUCTION EFFECT OF ONE-DIMENSIONAL DUCT WITH RANDOMNESS,   2005 03
  • Blind Separation for 3 Signals in Terms of Complex Hermite Moment and 3-dimensional Unitary Transformation,   2005 03
  • Fundamental consideration on sound reduction property in one-dimensional duct with random media.,   2004 09
  • Two-stage filters for canceling a one-dimensional duct noise based on transmission-line model, The 47th IEEE International Midwest Symposium on Circuit Systems (MWSCAS),   2004 08 , The 47th IEEE International Midwest Symposium on Circuit Systems (MWSCAS)
  • ANC of one-dimensional duct based on equivalent circuit model, International Congress on Acoustics 2004 (ICA2004),   2004 04 , International Congress on Acoustics 2004 (ICA2004)
  • The effect of non-objective component on the parameter estimation in independent component analysis,   2004 03
  • On the ANC in one-dimensional duct and the filter design for control,   2003 11
  • Direction findings of arrival sound based on the blind source separation and restoration of signals with inverse filtering,   2003 11
  • The estimation of sound source positions based on the estimated parameters of the complex ICA,   2003 11
  • Active noise control for one-dimensional duct using equivalent circuit representation,   2003 09
  • On active noise control for one-dimensional sound field based on equivalent circuit model,   2003 09
  • ANC of one.dimensional duct based on equivalent circuit model and its simulation,   2003 05
  • Sound source localization from time.shifted mixtures by complex blind separation and inverse filter design for separation/reproduction simulation on speech data,   2003 03
  • Sound source localization based on the estimated parameters by complex ICA and restoration of signals blind separation for time-shifted mixtures and inverse filtering,   2003 03
  • Simple estimation methods of the mixed wind noise in the environmental low.frequency noise measurement application for the estimation of aircraft noise or wind turbine generator noise,   2003 03
  • Prediction of wind noise and estimation of sound signal based on wind speed information considering time-variant system,   2003 01

Misc

  • Considering visibility of vascular virtual handling system for endovascular intervention assistance, Toshihiro SHINOHARA, Yoshiji NISHIDA, Noboru NAKASAKO, Computer Assisted Radiology and Surgery (CARS 2019) Proceedings of the 33th International Congress and Exhibition,   2019 06
  • ACOUSTIC DISTANCE USING CROSS-SPECTRUM BETWEEN ADJACENT TWO-CHANNEL OBSERVATIONS BASED ON PHASE INTERFERENCE (DISTANCE MEASUREMENT FOR PARABOLIC TARGET), Noboru Nakasako, Shinya Honda, Toshihiro Shinohara, Tetsuji Uebo, Proc. on the 25th International Congress on Sound and Vibration (ICSV25), 8ページ(CD-ROM収録),   2018 07
  • Vascular virtual handling in three-dimensional image for endovascular intervention assistance, Toshihiro Shinohara, Yoshiji Nishida, Noboru Nakasako, Mitsuhiro Ogura, Computer Assisted Radiology and Surgery (CARS 2018) Proceedings of the 32th International Congress and Exhibition,   2018 06
  • AN ATTEMPT OF DISTANCE MEASUREMENT FOR A HUMAN BASED ON PHASE INTERFERENCE USING BEAM-STEERING AT EACH CHANNEL OF PARAMETRIC ARRAY LOUDSPEAKER, N. Nakasako, T. Nakano, T. Shinohara, M. Nakayama, T. Uebo, Proc. on the 24th International Congress on Sound and Vibration (ICSV24), 8ページ(CD-ROM収録),   2017 07
  • ACOUSTIC DISTANCE MEASUREMENT BASED ON PHASE INTERFERENCE BETWEEN TRANSMITTED AND REFLECTED WAVES AND POSITION ESTIMATION BY USING KINECT V2'S MICROPHONE ARRAY, R. Oda, T. Shinohara, T. Uebo, N. Nakasako, Proc. on the 24th International Congress on Sound and Vibration (ICSV24), 8ページ(CD-ROM収録),   2017 07
  • ACOUSTIC DISTANCE MEASUREMENT BASED ON THE INTERFERENCE BETWEEN TRANSMITTED AND REFLECTED WAVES USING CROSS-SPECTRAL METHOD BY INTRODUCING ANALYTIC SIGNAL OF LINEAR CHIRP AND HILBERT TRANSFORM FILTER, K. Sakaguchi, S. Honda, T. Shinohara, T. Uebo, N. Nakasako, Proc. on the 24th International Congress on Sound and Vibration (ICSV24), 8ページ(CD-ROM収録),   2017 07
  • AN IMPLEMENTATION ON PROTOTYPE COMPACT SYSTEM OF TWO-CHANNEL ACOUSTIC DISTANCE MEASUREMENT METHOD MEASURABLE FROM 0M BASED ON THE STANDING WAVE CONSIDERING DIRECT CURRENT COMPONENT AND PHASE SPECTRUM, C. Song, T. Shinohara, T. Uebo, N. Nakasako, Proc. on the 24th International Congress on Sound and Vibration (ICSV24), 8ページ(CD-ROM収録),   2017 07
  • ACOUSTIC CHARACTERISTICS OF BIVALVE AND POSSIBILITY OF AUTOMATICALLY DISCRIMINATING DEFECTIVE BIVALVE USING ACOUSTIC SIGNAL, S. Murata, T. Shinohara, T. Nakano, N. Nakasako, Proc. on the 24th International Congress on Sound and Vibration (ICSV24), 8ページ(CD-ROM収録),   2017 07
  • パラメトリックスピーカを用いた位相干渉に基づく音響測距と音源提示の試み, 中野智史, 篠原寿広, 上保徹志, 中山雅人, 中迫昇, 日本音響学会研究発表会講演論文集(CD-ROM), 2017, ROMBUNNO.1‐P‐33,   2017 03 01 , http://jglobal.jst.go.jp/public/201702253695844870
  • Acoustic distance measurement based on the interference between transmitted and reflected waves using cross-spectral method by introducing analytic signal of linear chirp sound, N. Nakasako, S. Honda, T. Shinohara, M. Nakayama, T. Uebo, 5th Joint Meeting of Acoustical Society of America and Acoustical Society of Japan,   2016 11
  • Acoustic distance measurement based on phase interference between transmitted and reflected waves, M. Nakayama, T. Nishiura, N. Nakasako, 5th Joint Meeting of Acoustical Society of America and Acoustical Society of Japan,   2016 11 , 招待有り
  • A Basic Study on Reflection Coefficient Estimation of Body Tissue by Ultrasound Using Phase Interference, Toshihiro Shinohara, Yurika Miyawaki, Noboru Nakasako, Tetsuji Uebo, Masato Nakayama, Proc. of u-Healthcare 2015, 145, 145,   2015 12
  • Acoustic Distance Measurement Method for Very Close Range Using Two-channel Microphones Based on Phase Interference and Removal of DC Component with Hough Transform, Noboru NAKASAKO, Kazuhiro SUZUKI, Toshihiro SHINOHARA, Masato NAKAYAMA, Tetsuji UEBO, Proc. of u-Healthcare 2015, 144, 144,   2015 12
  • A practical method to estimate the distance and velocity utilizing interference of a linear chirp (Invited paper), N. Nakasako, S. Hanabusa, M. Nakayama, T. Shinohara, T. Uebo, Proc. on the 22nd International Congress on Sound and Vibration (ICSV22),   2015 07
  • A trial on calculating the equivalent reflection coefficient by acoustic distance measurement method based on phase interference in the actual sound actual field, N. Nakasako, Y. Neki, M. Nakayama, T. Shinohara, T. Uebo, Proc. of inter-noise 2014,   2014 11
  • Robust acoustic distance measurement method based on synchronous addition using cross-spectral method in a noisy environment, K. Suzuki, N. Nakasako, M. Nakayama, T. Shinohara, T. Uebo, Proc. on the 21st International Congress on Sound and Vibration (ICSV21),   2014 07
  • Effect of a measurement system on 1ch acoustic distance measurement based on phase interference and its correction by considering adjacent frequency components of the power spectrum, N. Nakasako, Y. Neki, M. Nakayama, T. Shinohara, T. Uebo, Proc. on the 21st International Congress on Sound and Vibration (ICSV21),   2014 07
  • Visualization of Vascular Diameter for Diagnostic Assistance of Cerebrovascular Diseases, Toshihiro Shinohara, Takuto Shiraishi, Masato Nakayama, Noboru Nakasako, Proc. of the 35th Annual International Conference of IEEE Engineering in Medicine and Biology Society,   2013 07
  • Estimation of Centerline and Diameter of Brain Vessel in 3D Head CTA Image by Using Model Matching Method, 篠原 寿広, 前川 将志, 中山 雅人, 中迫 昇, International Forum on Medical Imaging in Asia,   2012 11
  • Estimation of distance from sound source using single microphone based on interference between transmitted and reflected waves, 中迫 昇, 篠原 寿広, 英 慎平, 上保 徹志, INTER-NOISE 2011, the 40th International Congress and Exposition on Noise Control Engineering,,   2011 09
  • Robust acoustic distance measurement method based on interference in noisy environments, Masato Nakayama, Shimpei Hanabusa, Noboru Nakasako, Tetsuji Uebo, Tetsuji Uebo, ISCIT 2010 - 2010 10th International Symposium on Communications and Information Technologies, 176, 181,   2010 12 01 , 10.1109/ISCIT.2010.5664833, http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=78651225530&origin=inward
    Summary:Distance to target is fundamental and very important information in many engineering fields. Many distance measurement methods with sound utilize the time delay of reflected wave which is measured with reference to transmitted one. This method, however, can not measure short distance because the transmitted wave, which has not attenuated enough as of reception of reflected waves, suppresses the reflected waves for short distance. Therefore we proposed acoustic distance measurement method based on interference between transmitted wave and reflected waves, which could measure distance in short range. However, the performance of our method was not discussed in noisy environments. In this paper, we focus discussion on noisy environments with additive noise. We describe our method using real measuring system in noisy environments. In addition, we propose suitable noise reduction for our method by applying an idea of synchronous addition and spectral subtraction in noisy environments. Finally, we confirm the effectiveness of our method using noise reduction through simulation and experiment. As a result, it has been confirmed that the distance can be measured at SNR = 5 or 15 dB by our method without using noise reduction and can be measured at SNR = -5 to 5 dB by our method using noise reduction. ©2010 IEEE.
  • Distance Estimation Method Measurable from 0m Based on Standing Wave Using Band-limited Sound with Uniform Amplitude and Random Phase, 河西 慶治, 中迫 昇, 篠原 寿広, 上保 徹志, The 2010 International Symposium on Communications and Information Technologies (ISCIT2010),   2010 10
  • Correction Method of Estimated Distance Using Geometrical Information on Sound Source and Microphone, 英 慎平, 中迫 昇, 篠原 寿広, 上保 徹志, 2009 Asia-Pacific Signal and Information Processing Association, Annual Summit and Conference,   2009 10
  • Distance Estimation and Compensation Method Using Band-limited Transmitted Wave with Uniform Amplitude and Random Phase Characteristics, 中迫 昇, 篠原 寿広, 英 慎平, 上保 徹志, The 24th International Technical Conference on Circuits/Systems, Computers and Communications,   2009 07
  • Identification of sound source position or direction based on the statistical independency in an actual sound environment(Project No. : 13650472), 1, 65,   2003 03
  • TRIAL OF ESTIMATING DISTANCE BASED ON THE INTERFERENCE OF AN AUDIBLE CHIRP, Noboru Nakasako, Yuta Tsuchida, Toshihiro Shinohara, Tetsuji Uebo, PROCEEDINGS OF THE 23RD INTERNATIONAL CONGRESS ON SOUND AND VIBRATION: FROM ANCIENT TO MODERN ACOUSTICS,   2016
    Summary:The distance to a target is fundamental information in many engineering applications, and an acoustical signal, especially an ultrasonic sound, often plays an essential role in measuring such a distance. Many proposed methods for measuring distance use the time delay between the transmitted and reflected waves, but it is difficult to measure short distances when the reflected waves are buried in the transmitted wave. Recently, a method to measure short distances using standing wave in the research field of microwave was proposed by T. Uebo et al. We applied the fundamental principles of that method to the estimation of short distances when using audible sound as the transmitted wave. This enables us to obtain the range spectrum from the power spectrum of the composite sound and to measure either short- or long-range distances, but it requires two applications of the Fourier transform. We propose a method for estimating distance that uses a chirp (a signal in which the frequency changes over time) as the transmitted wave, because the period of the power fluctuation of the composite sound will be inversely proportional to the distance between the microphone and the target. We confirmed the validity of the chirp -based distance estimate by performing a computer simulation and by applying it to an actual sound field.
  • A TRIAL OF ACOUSTICAL DISTANCE MEASUREMENT BASED ON PHASE INTERFERENCE USING AN ULTRASONIC SOUND, Tomofumi Nakano, Toshihiro Shinohara, Tetsuji Uebo, Noboru Nakasako, Masato Nakayama, PROCEEDINGS OF THE 23RD INTERNATIONAL CONGRESS ON SOUND AND VIBRATION: FROM ANCIENT TO MODERN ACOUSTICS,   2016
    Summary:In order to achieve the realistic sensation of sound, sound field reproduction technique plays a very important role. The sound field reproduction technology is roughly classified into binaural and transaural reproduction systems. The former has a merit that it can be implemented in small scale systems under the assumption of the headphone listening but it is somewhat burdensome to wear the headphone. Although the latter does not require headphones, it requires large scale system to reproduce the sound field. In this paper, we focus on the development of small scale sound reproduction system. If the distance between sound source and listener is a priori known, it may be possible to reproduce the sound field more accurately. As a method of distance estimation for a target, acoustical distance measurement (ADM) was proposed based on phase interference using audible sound. However, measurement of audible sound has the potential to record private information such as conversation, which may yield a privacy issue. There is a reproduction method of sound field by parametric loudspeaker using ultrasonic sound. Therefore, in order to reproduce sound field more accurately, protecting personal conversation from the sound measurement, this paper describes a new method to estimate the distance using an ultrasonic wave. This acoustic distance measurement is based on interference between direct wave and reflected wave using ultrasonic wave. First, the composite wave of direct wave and reflected wave is observed, and then the power spectrum of the composite wave is obtained by Fourier transform. The power spectrum of composite wave is a periodical function whose period is inversely proportional to the distance between microphone and target. Finally, by applying Fourier transform again to the power spectrum, the range spectrum is obtained, whose peak position corresponds to the distance. To confirm the effectiveness of the proposed method, it is applied to the actual situation of distance measurement by using ultrasonic sound.
  • ESTIMATING THE DISTANCE TO A SOUND SOURCE, USING SINGLE-CHANNEL CROSS-SPECTRAL METHOD BETWEEN OBSERVED AND PSEUDO-OBSERVED WAVES BASED ON PHASE INTERFERENCE, Shinya Honda, Toshihiro Shinohara, Tetsuji Uebo, Noboru Nakasako, PROCEEDINGS OF THE 23RD INTERNATIONAL CONGRESS ON SOUND AND VIBRATION: FROM ANCIENT TO MODERN ACOUSTICS,   2016
    Summary:In acoustic applications, it is often important to estimate the distance to the sound source. The conventional way to estimate the distance to the target is based on the time delay between the transmitted and reflected waves, but this method cannot be used when the reflected wave is buried in the transmitted wave. Thus, a method has been proposed that uses the interference between the transmitted and reflected waves to estimate the distance to the target. In an existing method for measuring acoustic distance based on phase interference, it has been shown that a spurious peak appears in the range spectrum (which is the absolute value of the Fourier transform of the power spectrum; the position of its peak corresponds to the distance). The spurious peak is caused by the measuring system from the loudspeaker to the microphone. To remove the effect of the measuring system, a single-channel cross-spectral analysis was applied to the observed wave and a pseudo observed wave, which was the result of convolving the transmitted wave with the impulse response of the measuring system, as measured in advance. We note that attaching a microphone to a target causes multiple reflections (interference between the sound source and the target). Thus, in this paper, we propose a method based on the phase interference to estimate the distance between a sound source and a target, using single-channel cross-spectral analysis of the observed wave and a pseudo-observed wave. We also present the results of applying the proposed method to estimating the distance to the source of a sound (human voice).
  • On distance measurement using band-limited noise, Noboru Nakasako, Tetsuji Uebo, Norimitsu Ohmata, Atsushi Mori, PROCEEDINGS OF SICE ANNUAL CONFERENCE, VOLS 1-8, 151, 156,   2007 , 10.1109/SICE.2007.4420968, http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=50249102636&origin=inward
    Summary:In many engineering fields, distance to target is fundamental and very important information, and often estimated or measured by using sound. To measure the distance to the target, time delay between reflected wave from transmitted wave is often used. However, it is difficult to measure short distance. Actually, ultrasonic range finders and ultrasonic level meters have minimum detectable range. Meanwhile, in the research field of microwave radar, a range finding method using standing wave is known for measuring short distances. It seems effective to use the standing wave of sound wave for measuring short distances. Moreover, in an actual situation of acoustic measurement, a random noise is very often utilized as well as a pure tone. Therefore, we focus our attention on audible sound and examine the distance estimation method using standing wave in audible sound. Specifically, we perform a computer simulation when audible sound, e.g., white noise, is used as a transmitted wave.
  • Simplified determination for the order of series type probability expression under introducing tolerance range and its application to traffic noise(jointly worked), Acoust. Sci. & Tech., Vol.22, No.5, pp.358-363,   2001 , 10.1250/ast.22.358
  • A Fundamental Consideration on the Stochastic Blind Signal Separation Based on the Rotational Transformation and a Measure of Statistical In dependency (jointly worked), Noboru Nakasako, Hisanao Ogura, Mitsuo Ohta, J. Acout. Soc. Jpn. (E), 21, 1, 49, 52,   2000 , 10.1250/ast.21.49
  • A Practical and Probabilistic Evaluation Method of Sound Insulation Systems Based on the Extended Regression Analysis for Roughly Observed Data(jointly worked), Noboru Nakasako, Yasuo Mitani, Mitsuo Ohta, J. Acoust. Soc. Jpn. (E), 19, 6, 391, 396,   1998 , 10.1250/ast.19.391
  • A fundamental study on the statistical evaluation of receiver response for an electromagnetic wave environment in multi-dimensional signal space - Theory and basic experiment, M Ohta, Y Mitani, N Nakasako, JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, 12, 5, 677, 699,   1998
    Summary:In this paper, a statistical electromagnetic (abbr., EM) interference study is constructed mainly from a theoretical viewpoint on the basis of N-dimensional random walk problem in multi-dimensional signal space. First, a characteristic function of the Hankel transform type matched to this EM environmental study is introduced especially in an extended form of D. Middleton's basic result. Then, the probability density function (abbr., pdf) is explicitly derived for the EM random fluctuation with a power scaled variable (or an effective value) measured by a receiver with a mean square operation. The proposed theory is verified by showing the agreement with one of D. Middleton's great researches as a special case of the proposed expressions. Moreover, the effectiveness of the proposed method is experimentally confirmed through an acoustic type simulation of EM environment and the application to a simplified actual EM environment with joint space-time non-Poisson interference as one of the same wave motion type environment as EM environment.
  • Identification and Probabilistic Response Prediction Methods for Actual Sound Iudulation Systems Contaminated by Background Noise(jointly worked), Noboru Nakasako, Mitsuo Ohta, J. Acoust. Soc. Jpn. (E), 19, 2, 113, 120,   1998 , 10.1250/ast.19.113
  • A probabilistic evaluation method of output response based on the extended regression analysis method for sound insulation systems with roughly observed data, N Nakasako, M Ohta, Y Mitani, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E80A, 8, 1410, 1416,   1997 08
    Summary:In this paper, a new trial for the signal processing is proposed along the same line as a previous study on the extended regression analysis based on the Bayes' theorem. This method enables us to estimate a response probability property of complicated systems in an actual case when observation values of the output response are roughly observed due to the quantization mechanism of measuring equipment. More concretely, the main purpose of this research is to find the statistics of the joint probability density function before a level quantization operation which reflects every proper correlation informations between the system input and the output fluctuations. Then, the output probability distribution for another kind of in put is predicted by using the estimated regression relationship. Finally, the effectiveness of the proposed method is experimentally confirmed by applying it to the actually observed input-output data of the acoustic system.
  • A prediction method of non-stationary time series data by using a modular structured neural network, E Watanabe, N Nakasako, Y Mitani, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E80A, 6, 971, 976,   1997 06
    Summary:This paper proposes a prediction method for non-stationary time series data with time varying parameters. A modular structured type neural network is newly introduced for the purpose of grasping the changing property of time varying parameters. This modular structured neural network is constructed by the hierarchical combination of each neural network (NNT: Neural Network for Prediction of Time Series Data) and a neural network (NNW: Neural Network for Prediction of Weights). Next, we propose a reasonable method for determination of the length of the local stationary section by using the additive learning ability of neural networks. Finally, the validity and effectiveness of the proposed method are confirmed through simulation and actual experiments.
  • A state estimation method in acoustic environment based on fuzzy observation contaminated by background noise - Utilization of inverse probability and digital filter, A Ikuta, M Ohta, N Nakasako, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E80A, 5, 825, 832,   1997 05
    Summary:In the measurement of actual random phenomenon, the observed data often contain the fuzziness due to the existence of confidence limitation in measuring instruments, permissible error in experimental data, some practical simplification of evaluation procedure and a quantized error in digitized observation. In this study, by introducing the well-known fuzzy theory, a state estimation method based on the above fuzzy observations is theoretically proposed through an establishment of wide sense digital filter under the actual situation of existence of the background noise in close connection of the inverse problem. The validity and effectiveness of the proposed method are experimentally confirmed by applying it to the actual fuzzy data observed in an acoustic environment.
  • A Precise Estimation Method of Probability Distribution Based on Roughly Observed Data with Quantized Level and Its Application to Environmental Sound Noise Measurement(jointly worked), Yasuo Mitani, Noboru Nakasako, Mitsuo Ohta, J. Acoust. Soc. Jpn. (E), 18, 4, 183, 190,   1997 , 10.1250/ast.18.183
  • A probabilistic evaluation method of discriminating system characteristics from background noise by use of multi-output observations in a complicated sound environment, N Nakasako, M Ohta, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E79A, 8, 1252, 1255,   1996 08
    Summary:This paper describes a trial of evaluating the proper characteristics of multiple sound insulation systems from their output responses contaminated by unknown background noises, The unknown parameters of sound insulation systems are first estimated on the basis of the linear time series on an intensity scale, describing functionally the input-output relation of the systems. Then, their output probability distributions are predicted when an arbitrary input noise passes through these insulation systems.
  • A Digital Filter of Restoring the Stochastic Signal Processing from Noisy and Quantized Level Observations, Trans.IEICE A, J79-A, 5, 1013,   1996
  • A Pratical Method of Predicting Leg by Use of Lx Data for Road Trafic Noise Based on the Introduction of Probabilistic Neural Networks (jointly worked), Noboru Nakasako, Mitsuo Ohta, J.Acoust.Soc.Jpn.(E), 17, 1, 27, 32,   1996 , 10.1250/ast.17.27
  • An Extended Evaluation Method of Non-Gaussian Type Sound Environment Utilizing the Generalized Capability in the Parallel Information Processing of Neural Network and Fuzzy Probability, J. Acoust. Soc. Jpn., 51, 4, 299,   1995 , 10.20697/jasj.51.4_299
  • STOCHASTIC SIGNAL-PROCESSING FOR INCOMPLETE OBSERVATIONS UNDER THE AMPLITUDE LIMITATIONS IN INDOOR AND OUTDOOR SOUND ENVIRONMENTS BASED ON REGRESSION-ANALYSIS, N NAKASAKO, M OHTA, H OGAWA, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E77A, 8, 1353, 1362,   1994 08
    Summary:A specific signal in most of actual environmental systems fluctuates complicatedly in a non-Gaussian distribution form, owing to various kinds of factors. The nonlinearity of the system makes it more difficult to evaluate the objective system from the viewpoint of internal physical mechanism. Furthermore, it is very often that the reliable observation value can be obtained only within a definite domain of fluctuating amplitude, because many of measuring equipment have their proper dynamic range and the original random wave form is unreliable at the end of amplitude fluctuation. It becomes very important to establish a new signal processing or an evaluation method applicable to such an actually complicated system even from a functional viewpoint. This paper describes a new trial for the signal processing along the same line of the extended regression analysis based on the Bayes' theorem. This method enables us to estimate the response probability property of a complicated system in an actual situation, when observation values of the output response are saturated due to the dynamic range of measuring equipment. This method utilizes the series expansion form of the Bayes' theorem, which is applicable to the non-Gaussian property of the fluctuations and various kinds of correlation information between the input and output fluctuations. The proposed method is newly derived especially by paying our attention to the statistical information on the input-output data without the saturation operation instead of that on the resultantly saturated observation, differing from the well-known regression analysis and its improvement. Then, the output probability distribution for another kind of input is predicted by using the estimated regression relationship. Finally, the effectiveness of the proposed method is experimentally confirmed too by applying it to the actual data observed for indoor and outdoor sound environments.
  • The Transformation Relationship of Dual Direction Type among Noise Evaluation Indices Lx's Based on an Improvement of the Principal Component Analysis Method, J. Acoust. Soc. Jpn., 50, 10, 829,   1994 , 10.20697/jasj.50.10_829
  • A PRACTICAL TRIAL OF DYNAMICAL STATE ESTIMATION FOR NON-GAUSSIAN RANDOM VARIABLE WITH AMPLITUDE LIMITATION AND ITS APPLICATION TO THE REVERBERATION TIME MEASUREMENT, N NAKASAKO, M OHTA, Y MITANI, IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, E76A, 9, 1392, 1402,   1993 09
    Summary:Most of actual environmental systems show a complicated fluctuation pattern of non-Gaussian type, owing to various kinds of factors. In the actual measurement, the fluctuation of random signal is usually contaminated by an external noise. Furthermore, it is very often that the reliable observation value can be obtained only within a definite fluctuating amplitude domain, because many of measuring equipments have their proper dynamic range and original random wave form is unreliable at the end of amplitude fluctuation. It becomes very important to establish a new signal detection method applicable to such an actual situation. This paper newly describes a dynamical state estimation algorithm for a successive observation contaminated by the external noise of an arbitrary distribution type, when the observation value is measured through a finite dynamic range of measurement. On the basis of the Bayes' theorem, this method is derived in the form of a wide sense digital filter, which is applicable to the non-Gaussian properties of the fluctuations, the actual observation in a finite amplitude domain and the existence of external noise. Differing from the well-known Kalman's filter and its improvement, the proposed state estimation method is newly derived especially by paying our attention to the statistical information on the observation value behind the saturation function instead of that on the resultant noisy observation. Finally, the proposed method is experimentally confirmed too by applying it to the actual problem for a reverberation time measurement from saturated noisy observations in room acoustics

Awards & Honors

  •   2007 06 , The China-Japan Joint Conference on Acoustics 2007, The Best Paper Award

Research Grants & Projects

  • Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(基盤研究(C)), Development of rear sonar using exhaust sound of automobile, The purpose of this study is to realize a rear-sonar of automobile for detecting obstacles(or targets) behind the automobile, using the exhaust sound of the automobile emitted from the automobile muffler. (1) We considered the fundamental properties and potentials of the distance estimation method based on the phase interference of audible sound. (2) We developed several methods, so as to reduce the error due to geometrical positions of the loudspeaker, target and microphone and the error due to the effect of the observation noise and measurement system. Furthermore, (3) we proposed a distance measurement method to measure the distance shorter than the minimum measurable distance.
  • Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(基盤研究(C)), Theoretical analysis of sound reduction property in one-dimensional random duct and its application to noise control, It is known that a wave cannot propagate long distance in random media and is confined in a small region when the field is excited. In physics it is called the "localization", the phenomenon which is closely related to the cut-off (non-propagating) state of waves in a certain broad frequency band. It is expected that this property can be utilized as a muffler to reduce the sound noise because the sound propagating in random media or random loadings would exhibit strong exponential decay along distance. On the other hand, a one-dimensional acoustic duct can be expressed by a transmission line model commonly used in the study of microwave waveguide. In this research, I focus on the sound decaying property of one-dimensional duct (random duct) and demonstrate the validity of the proposed theory through a computer simulation. The results I obtained in 2005 and 2006 are listed below.[2005 year] : As the first step of research, I expressed the sound field in duct by a transmission line model, on which I theoretically analyzed the ordinary one-dimensional duct and carried out computer simulation. Based on the circuit representation, I theoretically proposed the sound reduction property in a case when there exist random media in duct. To confirm the validity of the analysis, I performed the computer simulation and showed the existence of the strong exponential decay. These results have been published in a scientific journal and presented in domestic conference.[2006 year] : Following to the fundamental consideration on the sound reduction problem with randomness in 2005, I theoretically proposed the sound reduction property in a case when there exist random loadings in duct and the extensive simulation makes it clear that the proposed method also enables us to cause the strong exponential decay. These results have been presented in international conferences.
  • Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(基盤研究(C)), Identification of sound source position or direction based on the statistical independecy in an actual sound environment, Sound source localization problem has been important in various actual fields of acoustics and many approaches have been developed e.g., MUSIC, etc. Most of them utilize only the lower order statistics of observations such as a covariance matrix and the orthogonality (or uncorrelation) between the objective signal and noise. Recently , Independent Component Analysis (ICA) becomes popular to solve a blind signal separation problem where independent sources are mixed and then measured by multiple sensors. The ICA of complex signals has been also proposed for a case when observations have time differences between source signals or are affected by system (room etc.).In this research, some trials of estimating the sound source positions or directions are proposed from various viewpoints. In particular, most of them are based on the statistical independency between source signals or between the source signal and an additional noise. The results we obtained in 2001 and 2002 are listed below.[2001 year]: As the first step of research, the correlation method is introduced to calculate the delay time between observations at each microphone and then to estimate the sound direction. In the second approach, MUSIC method and Kalman filter are employed, respectively, to estimate the direction of source and to detect the amplitude information for sound source localization.The third method is a trial of estimating the time delays or the distances between receivers and sound sources based on the complex ICA, especially for the mixed observations with time delays. Further, we can easily construct an inverse filter to separate the (over-all) real mixed signals using the parameters estimated by ICA, while the usual complex ICA required synthesizing all frequency components. Finally, through fundamental simulation, we demonstrate the high-quality blind separation as well as the validity for the estimation of the source parameters.[2002 year]: Following to the fundamental consideration on the sound source localization problem in 2001, the extensive simulation makes it clear that the proposed method also enables us to find the directions of arrival. These results have been presented in domestic or international conferences.
  • Theory of Independent Component Analysis and Its Application to Actual Data
  • Neural Networks, Fuzzy Theory and Genetic Algorithm and Their Application to Random Signal Processing
  • Development of Signal Processing Algorithm and Its Application to Environmental System