九州大学 研究者情報
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實松 豊(じつまつ ゆたか) データ更新日:2019.07.03

准教授 /  システム情報科学研究院 情報学部門 数理情報


主な研究テーマ
深層学習を利用したMRI撮像の高速化
キーワード:MRI, Deep Learning, Deep Neural Networks, Image Super Resolution
2017.04~2020.03.
通信路符号化逆定理における正復号指数の評価と指数の計算アルゴリズム
キーワード:正復号確率,誤り指数,反復アルゴリズム
2014.03~2017.03.
圧縮センシングに基づくレーダー信号処理
キーワード:圧縮センシング, Rate of Innovation 信号, Prony's 周波数推定法
2014.04~2017.03.
β変換器の量子化誤差
キーワード:AD/DA変換器,β進展開,PCM, ΣΔ変換,量子化誤差
2012.10~2014.03.
マルチユーザ検出器とスピングラス
キーワード:スピングラス,統計物理,ランダム行列,ニューラルネットワーク,連想記憶
2005.04~2014.03.
2次元の拡散符号信号による時間・周波数同期確立
キーワード:不確定性関数,ウィグナー分布,拡散符号
2001.04.
従事しているプロジェクト研究
最先端研究開発支援プログラム「複雑系数理モデル学の基礎理論構築とその分野横断的科学技術応用」
2010.03~2014.03, 代表者:合原 一幸, 東京大学, 総務省(日本)
我が国独自の学問「数理工学(Mathematical Engineering)」やカオス、フラクタル、複雑ネットワークなどの工学応用を目指す「カオス工学(Chaos Engineering)」を基にして、複雑系数理モデル学の構築とその様々な分野横断的科学技術応用を目指す。.
合原複雑数理モデルプロジェクト
2006.12~2008.10, 代表者:合原 一幸, 東京大学, ERATO,JST(日本)
最近Princeton大のDaudechiesらにより提案されたベータ変換を用いるA/D変換にカオス力学系の立場からの検証を行う. A/D変換における標本化・量子化という根本問題にカオス理論による考察を行うことを目的とする..
研究業績
主要原著論文
1. Dongshin Yang, Yutaka Jitsumatsu, Super resolution channel estimation by using spread spectrum signal and atomic norm minimization, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, 10.1587/transfun.E101.A.2141, E101A, 12, 2141-2148, 2018.12, [URL], Compressed Sensing (CS) is known to provide better channel estimation performance than the Least Square (LS) method for channel estimation. However, multipath delays may not be resolved if they span between the grids. This grid problem of CS is an obstacle to super resolution channel estimation. An Atomic Norm (AN) minimization is one of the methods for estimating continuous parameters. The AN minimization can successfully recover a spectrally sparse signal from a few time-domain samples even though the dictionary is continuous. There are studies showing that the AN minimization method has better resolution than conventional CS methods. In this paper, we propose a channel estimation method based on the AN minimization for Spread Spectrum (SS) systems. The accuracy of the proposed channel estimation is compared with the conventional LS method and Dantzig Selector (DS) of the CS. In addition to the application of channel estimation in wireless communication, we also show that the AN minimization can be applied to Global Positioning System (GPS) using Gold sequence..
2. Dongshin Yang and Yutaka Jitsumatsu, Dividing the grids of compressed sensing for channel estimation and investigating Markov codes, Nonlinear Theory and Its Applications, IEICE, https://doi.org/10.1587/nolta.9.259, 9, 2, 259-267, 2018.04, [URL].
3. YUTAKA JITSUMATSU, Kazuya Matsumura, A β-ary to binary conversion for random number generation using a β encoder, Nonlinear Theory and Its Applications, IEICE, http://doi.org/10.1587/nolta.7.38, 7, 1, 38-55, 2016.01, [URL], A β encoder is an analog-to-digital (A/D) converter, proposed by Daubechies et al. in 2002, that outputs a truncated sequence of β expansion of an input value x. It is known that the conventional pulse code modulation (PCM) that outputs the binary expansion of x is sensitive to the offset of the threshold voltage, while a β encoder is robust to such an offset. We propose an algorithm that calculates the binary expansion of an interval that is identified by an output sequence from a β encoder. Such a method is referred to as a β-ary to binary converter. We generate sequences of random numbers, using a hardware β encoder followed by the β-ary to binary converter. The randomness of the generated binary random numbers is verified by the National Institute of Standards and Technology (NIST) statistical test suite..
4. YUTAKA JITSUMATSU, Tohru Kohda, Digital Phase Updating Loop and Delay-Doppler Space Division Multiplexing for Higher Order MPSK, 7th Int. Workshop Multiple Access Communications, 10.1007/978-3-319-10262-7_1, 8715, 1-15, 2014.12, [URL], An alternative to the use of higher order Quadrature Amplitude Modulation (QAM) that shows strong variations of output amplitude is the use of higher order Phase Shift Keying (PSK). The bit error probability of higher order PSK is sensitive to phase distortion that is caused by propagation delay and Doppler frequency estimation errors. Phase Updating Loop (PUL) is a generalization of a Phase Locked Loop (PLL) that can estimate the delay and the Doppler accurately. In order to realize a higher order PSK, we recently proposed a delay-Doppler Space Division Multiplexing (dD-SDM) method in which a parameter space consisting of delay and Doppler is partitioned into several sub-spaces and each subspace has its assigned signature codes. In this paper, digital PUL is defined. Simulation results show that by the use of the dD-SDM method together with digital PUL we can successfully demodulate 256PSK data..
5. YUTAKA JITSUMATSU, Tatsuro Higuchi, Masahiro Hashiguchi, Optimal Sign Patterns for a Generalized Schmidl-Cox Method, Sequences and Their Applications 2014, 10.1007/978-3-319-12325-7_23, 8865, 269-279, 2014.11, [URL], The timing synchronization method proposed by Schmidl and Cox for orthogonal frequency division multiplexing (OFDM) systems uses a reference block consisting of two identical parts, while the one proposed by Shi and Serpedin uses a reference block consisting of four parts with a sign pattern (+1,+1,−1,+1). The accuracy of estimated delays of the latter method is higher than the former. In this paper, the number of partitions is generalized as an integer number M. Two criteria for optimization are proposed. Optimal codes with code length 5≤M≤30 are investigated..
6. YUTAKA JITSUMATSU, Tohru Kohda, Kazuyuki Aihara, Delay-Doppler Space Division-based Multiple-Access Solves Multiple-Target Detection, Lecture Notes in Computer Science, 10.1007/978-3-319-03871-1_5, 8310, 39-53, 2013.12, [URL].
7. YUTAKA JITSUMATSU, Welch Bound for Bandlimited and Timelimited Signals, Lecture Notes in Computer Science, 7280, 269-278, 2012.09, [URL], Synchronisation must be established in any communication systems. In multicarrier communications, time and frequency offsets are taken into account. We use cross-ambiguity function to evaluate synchronisation performance and the interference in a CDMA system with such two-dimensional offsets. Welch bound for one dimensional and discrete time cross correlation function is extended to the one for two dimensional and continuous time cross ambiguity functions. This bound is compared with an ambiguity function for continuous time signal generated from discrete time signal with rectangular chip waveforms..
8. Y. Jitsumatsu and T. Kohda, Asynchrony, Markov, interference, RIMS Kokyuroku, 1742, 165-179, 2011.05, [URL].
9. Yutaka Jitsumatsu and Tohru Kohda, Chip-Asynchronous Version of Welch Bound: Gaussian Pulse Improves BER Performance,, Sequences and Their Applications - SETA 2006, vol.4086, pp.351-363, 2006.09.
10. Yutaka Jitsumatsu, Tahir Abbas Khan and Tohru Kohda, Reduction of MAI in Asynchronous DS/CDMA Systems Using Post-Filter, IEICE Tranactions on Fundamentals, E87A, 9, 2301-2307, Vol. E87-A, No.9, pp. 2301-2307, 2004.09.
11. Jitsumatsu, Y.; Kohda, T., Bit error rate of incompletely synchronised correlator in asynchronous DS/CDMA system using SS Markovian codes, Electronics Letters, 10.1049/el:20020276, 38, 9, 415-416, Volume: 38 Issue: 9, Page(s): 415 -416, 2002.04.
主要学会発表等
1. Dongshin Yang and Yutaka Jitsumatsu, Super Resolution Channel Estimation with Spread Spectrum Signal and Atomic Norm Minimization, 2018 International Symposium on Information Theory and Its Applications (ISITA), 2018.10, [URL], One of the important tasks in wireless communications is propagation delay estimation. It has been found that the channel estimation accuracy of compressed sensing is superior to the existing method based on signal parameter estimation through MUltiple SIgnal Classification (MUSIC) and Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT). However, there is a problem in the method that multipath delays may not be resolved if they span between the grids. This problem leads to inaccurate channel estimation. In this paper, we describe the Atomic Norm Minimization (ANM) that enables super resolution channel estimation. In additions, we propose ANM by using Spread Spectrum (SS) signal. In this study, we show new experiments using Gold code for Global Positioning System (GPS). We have also added a new experiment to check the performance of the ANM with SS signal..
2. Yeelai Chew, YUTAKA JITSUMATSU, Estimation of Beta-Value for Pipelined Beta Encoders, Int. Symp. Nonliner Theory and its Application (NOLTA2016), 2017.11, [URL].
3. Koji Itaya, YUTAKA JITSUMATSU, Random Number Generation Using Outputs from Multiple Beta Encoders, Int. Symp. Nonliner Theory and its Application (NOLTA2016), 2017.11, [URL].
4. Yutaka Jitsumatsu, On computation of secrecy exponent functions, The 40th Symp. on Inform. Theory and its Applications (SITA2017), 2017.11, [URL].
5. D. Yang and Y. Jitsumatsu, Channel Estimation by Using Spread Spectrum Signal and Atomic Norm Minimization, The 40th Symp. on Inform. Theory and its Applications (SITA2017), 2017.11, [URL].
6. Dongshin Yang, YUTAKA JITSUMATSU, Compressive Sensing of Up-Sampled Model and Atomic Norm for SuperResolution Radar, 2017 Int. Radar Sympo. (IRS2017), 2017.06, [URL].
7. YUTAKA JITSUMATSU, Computation of the Random Coding Secrecy
Exponent for a Constant Composition Ensemble, Proc. Int. Sympo. Inform. Theory, 2017.06, [URL].
8. Dongshin Yang, YUTAKA JITSUMATSU, Discretization in Channel Estimation Using Compressed Sensing and Its Performance Improvement, 13th IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS 2016), 2016.08, [URL].
9. YUTAKA JITSUMATSU, Yasutada Oohama, Computing the Optimal Exponent of Correct Decoding for Discrete Memoryless Sources, Proc. Int. Sympo. Inform. Theory, 2016.07, [URL], The form of
Dueck and K\"orner's exponent function for
correct decoding probability for discrete memoryless channels
at rates above the capacity
is similar to
the form of
Csisz\'ar and K\"orner's exponent function for
correct decoding probability i.
10. 實松 豊, 大濱靖匡, A New Iterative Algorithm for Computing the Optimal Exponent of Correct Decoding Probability for Discrete Memoryless Channels under Input Constraint, 第38回情報理論とその応用シンポジウム, 2015.11.
11. Shuntaro Ito, Dongshin Yang, YUTAKA JITSUMATSU, Estimation of Multi-path Channels by Using the Annihilating Filter Method, 2015 IEEE 82nd Vehicular Technology Conference, 2015.09, [URL], Estimation of
the channel distortion {characteristics} is of crucial importance
for realizing a reliable communication.
In order to estimate the channel,
a received signal is sampled at some rate.
The Nyquist rate is widely used notion to determine the sampling rate
of the received signal.
On the other hand, Vetterli introduce{d} the concept of rate of innovation
that is the degree of freedom of the signal space and proposed annihilating
filter method, which solves a nonlinear simultaneous equation
by means of finding roots of the characteristic polynomial of the equation.
By using this technique, the number of samples can be reduced
from the Nyquist rate.
In this paper, we employ the annihilating filter method to perform
the estimation of a multi-path channel.
A spread spectrum signal with a wide bandwidth is transmitted,
while the received signal is sampled at a very low sampling rate
that is determined according to the rate of innovation..
12. Yasutada Oohama, YUTAKA JITSUMATSU, A New Iterative Algorithm for Computing the Optimal
Exponent of Correct Decoding for Discrete Memoryless Channels, Int. Sympo. Inform. Theory 2015, 2015.06, [URL], For a discrete memoryless channel,
a lower bound for the correct decoding
probability exponent
was derived by Arimoto.
He also gave an iterative algorithm for computing
the exponent.
Subsequently, Dueck and K\"orner determined the optimal
exponent function of the correct decoding probability.
In this paper, a new iterative algorithm that
computes Dueck and K\"orner's exponent is presented.
.
13. YUTAKA JITSUMATSU, Masahiro Hashiguchi, Tatsuro Higuchi, Optimal Sign Patterns for a Generalized Schmidl-Cox Method, Sequences and Their Applications 2014, 2014.11, [URL].
14. Tatsuro Higuchi, YUTAKA JITSUMATSU, Performance Analysis of a Time Synchronization Method
for Multipath Fading Channels with Doppler Shift, 17th Int. Symp. on Wireless Personal Multimedia Commun. (WPMC2014), 2014.09, [URL].
15. YUTAKA JITSUMATSU, Tohru Kohda, Kazuyuki Aihara, Phase-tuned layers with multiple 2D SS codes realize 16PSK communication, 2014 IEEE Wireless Communications and Networking Conference , 2014.04, [URL].
16. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Delay-Doppler Space Division- based Multiple-Access Solves Multiple-Target Detection
, 6th International Workshop on Multiple Access Communications(MACOM2013), 2013.12.
17. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Recovering noncoherent MPSK signal with unknown delay and Doppler using its ambiguity function, 4th International Workshop on Recent Advances in Broadband Access Networks(RABAN2013), 2013.11.
18. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, PLL-free Receiver for Gabor Division/Spread Spectrum System, The 9th IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob2013), 2013.10.
19. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Signals that can be easily time-frequency synchronized from their ambiguity function
, IEEE Information Theory Workshop 2013(ITW2013), 2013.09.
20. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Gabor Division/Spread Spectrum System is Separable in Time and Frequency Synchronization
, 2013 IEEE 78th Vehicular Technology Conference: VTC2013-Fall, 2013.09.
21. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Spread Spectrum-Based Cooperative and individual time-frequency synchronization
, The Tenth International Symposium on Wireless Communication Systems(ISWCS2013) , 2013.08.
22. Yutaka Jitsumatsu, Tohru Kohda, Kazuyuki Aihara, Separability of Time-Frequency Synchronization
, International Radar Symposium 2013 (IRS2013) , 2013.06.
23. YUTAKA JITSUMATSU, Tohru Kohda, Kazuyuki Aihara, Frequency-division spread-spectrum makes frequency synchronisation easy, IEEE Globecom 2012, 2012.12.
24. Tohru Kohda and Yutaka Jitsumatsu and Kazuyuki Aihara, Markovian SS Codes Flatten the Spectrum of UWB Gaussian Pulse, 2011 IEEE Int. Conf. on Ultrawide band, 2011.09.
25. T. Kohda and Y. Jitsumatsu, 2D Markovian SS codes flatten Time-frequency distribution of signals in asynchronous Gabor division CDMA systems, 2011 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP2011), 2011.05.
26. T. Kohda, Y. Jitsumatsu, K. Fujino and K. Aihara, Frequency division (FD)-based CDMA system which permits frequency offset, 2010 Int. Sympo. on Spread Spectrum Techniques and Applications (ISSSTA2010), 2010.10.
27. Yutaka Jitsumatsu and Tohru Kohda, Quasi-Orthogonal Multi-Carrier CDMA, IEEE Globecom 2008, 2008.12, [URL].
28. Yutaka Jitsumatsu and Tohru Kohda, Markov codes make Gaussian pulse superior to a raised cosine pulse, 10th IEEE Int. Symp. Spread Spectrum Techniques and Applications, 2008.08, [URL].
29. Yutaka Jitsumatsu and Tohru Kohda, Prolate spheroidal wave functions induce Gaussian chip waveforms, 2008 IEEE Int. Symp. Inform. Theory (ISIT), 2008.07.
30. Yutaka Jitsumatsu and Tohru Kohda, Welch Bound for FIR Lowpass Filtered Sequences, 2007 IEEE Int. Symp. Inform. Theory, 2007.06.
31. Yutaka Jitsumatsu and M. Tahir Abbas Khan and Tohru Kohda, Gaussian Chip Waveform Together with Markovian Spreading Codes Improve BER Performacnce in Chip-Asynchronous CDMA Systems, Proc. of Globecom 2006, 2006.11.
32. Yutaka Jitsumatsu and Tohru Kohda, Chip-Asynchronous Version of Welch Bound: Gaussian Pulse Improves BER Performance, Sequences and Their Applications - SETA 2006, 2006.09.
33. Yutaka Jitsumatsu and Tohru Kohda, A lower bound on the mean squared correlations for band-limited asynchronous DS/CDMA systems, Proc. of 2006 IEEE Int. Symp. on. Information Theory, 2006.07.
特許出願・取得
特許出願件数  10件
特許登録件数  3件
学会活動
所属学会名
情報理論とその応用学会
IEEE
電子情報通信学会
学協会役員等への就任
2019.06~2021.06, 電子情報通信学会, 幹事.
2019.06~2021.06, 電気情報通信学会, 通信方式研究専門委員.
2017.05~2017.05, 電子情報通信学会 NOLTAソサイエティ, 運営委員.
2014.05~2020.05, 電気情報通信学会, 情報理論研究専門委員.
2013.05~2015.05, 電子情報通信学会, 基礎・境界ソサイエティ,SITAサブソ委員,SITA担当.
2010.06~2016.05, 電子情報通信学会 基礎・境界ソサイエティ, CAS専門委員.
2008.04~2010.03, 情報理論とその応用学会, 幹事.
学会大会・会議・シンポジウム等における役割
2019.12.02~2019.12.06, International Symposium on Nonlinear Theory and Its Applicatoins (NOLTA2019), プログラム編集委員.
2018.10.28~2018.10.31, International Symposium on Information Theory and Its Applications 2018, General Secretaries.
2017.02.23~2017.02.23, 第1回情報理論および符号理論とその応用ワークショップ, 座長(Chairmanship).
2016.11.27~2016.11.30, 2016 International Symposium on Nonlinear Theory and Its Applications , 座長(Chairmanship).
2015.07.13~2015.07.14, 情報理論研究会, 座長(Chairmanship).
2015.03.16~2015.03.18, JEC-ECC2015, 座長(Chairmanship).
2014.03.21~2014.03.22, 情報とダイナミクスV研究集会, 実行委員.
2013.08.30~2013.08.30, Workshop on Modern Error Correcting Codes , Organizer.
2012.03.16~2012.03.17, 情報とダイナミクスIV研究集会, 実行委員.
2011.08.01~2013.03.01, 情報理論とその応用シンポジウム(SITA)2012, 総務.
2011.01.26~2011.01.26, 電子情報通信学会 回路とシステム研究会, 座長(Chairmanship).
2010.09.26~2010.09.26, 電気関連学会九州支部連合大会, 座長(Chairmanship).
2009.11.30~2009.12.05, 情報理論とその応用シンポジウム(SITA)2009, 編集.
2009.03.09~2009.03.10, 電子情報通信学会 情報理論研究会, 座長(Chairmanship).
2008.09.07~2008.09.10, 2008 International Symposium on Nonlinear Theory and its Applications, 座長(Chairmanship).
2006.09~2006.09, 2006 International Symposium on Nonlinear Theory and Its Applications, 座長(Chairmanship).
2005.09~2005.09, 2005 International Symposium on Nonlinear Theory and Its Applications, 座長(Chairmanship).
2005.05~2005.05, 2005 IEEE International Symposium on Circuits and Systems, 座長(Chairmanship).
2004.11~2004.11.24, 2004 International Symposium on Nonlinear Theory and Its Applications (NOLTA2004), Secretary.
2003.10~2003.10, 電気関係学会九州支部連合大会, 座長(Chairmanship).
学会誌・雑誌・著書の編集への参加状況
2012.05~2016.05, 電子情報通信学会・英文論文誌A, 国内, 編集委員.
2008.12~2010.08, 電子情報通信学会/英文論文誌A/情報理論とその応用特集号, 国内, 編集委員.
2009.12~2011.08, 電子情報通信学会/英文論文誌A/情報理論とその応用特集号, 国内, 編集委員.
学術論文等の審査
年度 外国語雑誌査読論文数 日本語雑誌査読論文数 国際会議録査読論文数 国内会議録査読論文数 合計
2018年度 10 
2017年度
2016年度    
2014年度    
2013年度
2013年度
2012年度  
2009年度
2010年度
2008年度 10    13 
2006年度    
2005年度    
2004年度    
その他の研究活動
海外渡航状況, 海外での教育研究歴
University of Maryland, UnitedStatesofAmerica, 2016.01~2016.10.
受賞
貢献賞, 一般社団法人 電子情報通信学会, 2014.09.
Best Paper Award, MACOM-2013 Chairs, 2013.12.
研究資金
科学研究費補助金の採択状況(文部科学省、日本学術振興会)
2019年度~2022年度, 基盤研究(C), 代表, 力学系に基づく乱数系列を用いた盗聴耐性付きスパース符号分割通信.
2007年度~2010年度, 基盤研究(B), 分担, 情報量概念を基盤とした学習理論の展開.
2017年度~2019年度, 基盤研究(C), 分担, 機械学習によるMRIの撮像時間短縮.
2016年度~2018年度, 基盤研究(C), 代表, ベータ写像に基づくAD変換器を用いた製造誤差に頑健なユニバーサル乱数生成.
2013年度~2016年度, 若手研究(B), 代表, オフセットを許容する時間・周波数領域同期法.
2008年度~2011年度, 基盤研究(B), 分担, 力学系理論による符号設計とそのディジタル通信への応用.
2008年度~2010年度, 若手研究(B), 代表, 空間ゆらぎのある記憶パタンを埋め込んだ連想記憶空間.
2005年度~2006年度, 萌芽研究, 分担, カオスに基づく擬似乱数を用いたスペクトラム拡散電子透かしシステム.
2005年度~2006年度, 若手研究(B), 代表, カオスに基くスペクトル拡散符号を用いたマルチユーザ同期捕捉.
2003年度~2006年度, 基盤研究(B), 分担, マルコフ性を有するカオス拡散符号を用いた非同期DS/CDMAシステム.
2004年度~2005年度, 特定領域研究(A)特定領域研究(B), 分担, カオスに基づいたi.i.d.2値系列によるストリーム暗号システム.
競争的資金(受託研究を含む)の採択状況
2019年度~2019年度, AMED, 代表, 多重解像度深層学習によるMRIの検査時間短縮.
2009年度~2013年度, 最先端研究開発支援プログラム(総務省), 分担, 複雑系数理モデル学の基礎理論構築とその分野横断的科学技術応用.

九大関連コンテンツ

pure2017年10月2日から、「九州大学研究者情報」を補完するデータベースとして、Elsevier社の「Pure」による研究業績の公開を開始しました。
 
 
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