Doctor of Engineering, Waseda University

information and communication engineering

information security

coding theory

network information theory

Informatics, Information theory

Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Communication and network engineering

Apr. 2024 - Present
The University of Electro-Communications, Graduate School of Informatics and Engineering, Professor

Apr. 2012 - Mar. 2024
The University of Electro-Communications, Graduate School of Informatics and Engineering, Associate Professor

Mar. 2008 - Mar. 2012
The University of Electro-Communications, Center for Frontier Science and Engineering, Assistant Professor

Apr. 2007 - Mar. 2008
Waseda University, Media Network Center, Assistant Professor

01 Apr. 2005 - 31 Mar. 2007
Media Network Center, Waseda University, Research Associate

Apr. 2003 - Dec. 2005
Waseda University, Graduate School of Science and Engineering, Department of Management and Systems Engineering

神奈川県立 横浜緑ヶ丘高校, Japan

Dec. 2024 - Present
プログラム委員長, 第48回情報理論とその応用シンポジウム, Society

May 2020 - Present
情報理論研究会研究専門委員, 電子情報通信学会, Society

Jun. 2018 - Present
査読委員, 電子情報通信学会

Sep. 2022 - Jul. 2025
Financial Co-Chair, 2024 International Symposium on Information Theory and its Applications, Society

Jun. 2018 - Apr. 2025
基礎境界ソサイエティ 編集幹事(総務), 電子情報通信学会

May 2022 - Dec. 2024
情報理論とその応用小特集編集委員, 電子情報通信学会, Society

Apr. 2024 - Nov. 2024
TPC Member, 2024 International Symposium on Information Theory and its Applications, Society

May 2023 - Dec. 2023
プログラム委員会委員, 第46回情報理論とその応用シンポジウム, Society

Dec. 2021 - Apr. 2023
実行委員 総務担当, 第45回情報理論とその応用シンポジウム, Society

Jun. 2018 - May 2022
編集委員, 電子情報通信学会 会誌編集委員会, Society

Jun. 2016 - May 2018
基礎境界ソサイエティ Fundamentals Review 編集正幹事, 電子情報通信学会

Jun. 2015 - May 2017
基礎境界ソサイエティ Fundamentals Review 編集幹事（WEB担当）, 電子情報通信学会

Jun. 2015 - May 2017
基礎境界ソサイエティ 電子広報担当幹事, 電子情報通信学会

May 2011 - Apr. 2017
情報理論研究会研究専門委員, 電子情報通信学会, Society

Jun. 2015 - May 2016
基礎境界ソサイエティ Fundamentals Review 編集幹事補佐, 電子情報通信学会

May 2013 - Apr. 2015
Research Society of Information Theory and Its Applications, IEICE, Society

May 2013 - Apr. 2015
情報理論とその応用サブソサイエティ 企画（国外）担当, 電子情報通信学会, Society

Jan. 2012 - Dec. 2013
Secretary of Information Theory Soc. Japan Chapter, IEEE, Society

Apr. 2007 - Mar. 2009
企画幹事, 情報理論とその応用学会, Society

Sep. 2021
電子情報通信学会 基礎・境界ソサイエティ編集委員会
査読委員としての貢献
電子情報通信学会 論文誌 編集活動感謝状

Sep. 2020
電子情報通信学会 基礎・境界ソサイエティ 貢献賞
電子情報通信学会 基礎・境界ソサイエティ 貢献賞

Sep. 2018
電子情報通信学会 基礎・境界ソサイエティ 貢献賞
電子情報通信学会 基礎・境界ソサイエティ 貢献賞

Sep. 2017
電子情報通信学会 基礎・境界ソサイエティ 貢献賞
電子情報通信学会 基礎・境界ソサイエティ 貢献賞

Sep. 2016
電子情報通信学会 基礎・境界ソサイエティ 貢献賞
電子情報通信学会 基礎・境界ソサイエティ 貢献賞

Nov. 2007
情報理論とその応用学会
2006年度 情報理論とその応用学会 奨励賞

Jan. 2007
東京電機大学
第30回 丹羽保次郎記念論文賞

Mar. 2006
早稲田大学
第16回 早稲田大学大川功記念論文賞

Outer bounds on the CEO problem with privacy constraints
Vamoua Yaghongka; Hideki Yagi; Hideki Ochiai
IEEE Trans. Inf. Forensics & Security, 20, 2, 1566-1581, Feb. 2025, Peer-reviwed
Scientific journal, English

Optimum achievable rates in two random number generation problems with f-divergences using smooth R\'enyi entropy.
Ryo Nomura; Hideki Yagi
Entropy, 26, 9, Sep. 2024, Peer-reviwed
Scientific journal, English

Variable-length resolvability for general sources and channels
Hideki Yagi; Te Sun Han
Lead, Entropy, 25, 10, Oct. 2023, Peer-reviwed
Scientific journal, English

Key agreement using physical identifiers for degraded and less noisy authentication channels
Vamoua Yachongka; Hideki Yagi; Hideki Ochiai
IEEE Trans. Inf. Forensics & Security, 18, 8, 5316-5331, Sep. 2023, Peer-reviwed
Scientific journal, English

Utility-privacy trade-offs with limited leakage for encoder
Naruki Shinohara; Hideki Yagi
Last, Proc. of 2023 IEEE Int. Symposium on Information Theory (ISIT2023), Jun. 2023, Peer-reviwed
English

Utility-privacy trade-offs with limited leakage for encoder
Naruki Shinohara; Hideki Yagi
Last, Entropy, 25, 6, 921, Jun. 2023, Peer-reviwed
Scientific journal, English

Biometric identification systems with both chosen and generated secret keys by allowing correlation
Vamoua Yachongka; Hideki Yagi
Last, IEICE Trans. Fundamentals, E106-A, 3, 382-393, Mar. 2023, Peer-reviwed
Scientific journal, English

Construction methods for error correcting output codes using constructive coding and their system evaluations
Shigeichi Hirasawa; Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Hiroshige Inazumi
Proc. of 2022 IEEE Int. Conference on Systems, Man, and Cybernetics (SMC2022), IEEE, 09 Oct. 2022, Peer-reviwed
International conference proceedings, English

Effect of Hamming distance on performance of ECOC with estimated binary classifiers
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Proc. of 2022 IEEE Int. Conference on Systems, Man, and Cybernetics (SMC2022), 111-116, Oct. 2022, Peer-reviwed
International conference proceedings, English

Performance analysis for biometric identification systems with nonlegitimate users
Hideki Yagi; Shigeichi Hirasawa
Lead, Proc. of 2022 IEEE Int. Conference on Systems, Man, and Cybernetics (SMC2022), 3057-3062, Oct. 2022, Peer-reviwed
International conference proceedings, English

Unified expression of utility-privacy trade-off in privacy-constrained source coding
Naruki Shinohara; Hideki Yagi
Last, Proc. of 2022 Int. Symposium on Information Theory and its Applications (ISITA2022), 198-202, Oct. 2022, Peer-reviwed
International conference proceedings, English

Performance evaluation of error-correcting output coding based on noisy and noiseless binary classifiers
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
Int. Journal of Neural Systems, World Scientific, 33, 2, 2350004-1-2350004-19, Oct. 2022, Peer-reviwed
Scientific journal, English

Secret key-based authentication with passive eavesdropper for scalar Gaussian sources
Vamoua Yachongka; Hideki Yagi; Yasutada Oohama
Proc. of 2022 IEEE Int. Symposium on Information Theory (ISIT2022), IEEE, 2685-2690, 26 Jun. 2022, Peer-reviwed
International conference proceedings, English

Performance evaluation of ECOC considering estimated probability of binary classifiers
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
Proc. of 10th World Conference on Information Systems and Technologies (WorldCIST2022), 12 Apr. 2022, Peer-reviwed
International conference proceedings, English

Analysis on optimal error exponents of binary classification for source with multiple subclasses
Hiroto Kuramata; Hideki Yagi
Last, Entropy, MDPI, 24, 5, 635, 1-27, Apr. 2022, Peer-reviwed
Scientific journal, English

Upper bounds on the error probability for the ensemble of linear block codes with mismatched decoding
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
IEICE Trans. Fundamentals, E105-A, 3, 363-371, 01 Mar. 2022, Peer-reviwed, In channel decoding, a decoder with suboptimal metrics may be used because of the uncertainty of the channel statistics or the limitations of the decoder. In this case, the decoding metric is different from the actual channel metric, and thus it is called mismatched decoding. In this paper, applying the technique of the DS2 bound, we derive an upper bound on the error probability of mismatched decoding over a regular channel for the ensemble of linear block codes, which was defined by Hof, Sason and Shamai. Assuming the ensemble of random linear block codes defined by Gallager, we show that the obtained bound is not looser than the conventional bound. We also give a numerical example for the ensemble of LDPC codes also introduced by Gallager, which shows that our proposed bound is tighter than the conventional bound. Furthermore, we obtain a single letter error exponent for linear block codes.
Scientific journal, English

Optimal error exponents of binary classification for sources with multiple subclasses
Hiroto Kuramata; Hideki Yagi
Last, Proc. of 2022 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2022), 21-23, 28 Feb. 2022, Peer-reviwed
International conference proceedings, English

Biometric identification systems with noisy enrollment for Gaussian sources and channels
Vamoua Yachongka; Hideki Yagi; Yasutada Oohama
Entropy, MDPI, 23, 8, 1049, 1-26, 15 Aug. 2021, Peer-reviwed
Scientific journal, English

A study on the optimization of the ECOC method for multi-label classification problems
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
IPSJ Trans. Mathematical Modeling and Its Applications, IPSJ, 14, 3, 1-10, 01 Aug. 2021, Peer-reviwed
Scientific journal, Japanese

Optimum intrinsic randomness rate with respect to f-divergences using the smooth min entropy
Ryo Nomura; Hideki Yagi
Proc. of 2021 IEEE Int. Symposium on Information Theory (ISIT2021), IEEE, 1784-1789, Jul. 2021, Peer-reviwed
International conference proceedings, English

Single-letter characterizations for information erasure under restriction on the output distribution
Naruaki Amada; Hideki Yagi
Last, IEICE Trans. Fundamentals, E104-A, 5, 805-813, 01 May 2021, Peer-reviwed
Scientific journal, English

Fundamental limits of biometric identification system under noisy enrollment
Vamoua Yachongka; Hideki Yagi
Last, IEICE Trans. Fundamentals, E104-A, 1, 283-294, 01 Jan. 2021, Peer-reviwed
Scientific journal, English

Biometric identification systems with both chosen and generated secrecy
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2020 Int. Symposium on Information Theory and its Applications (ISITA2020), 24 Oct. 2020, Peer-reviwed
International conference proceedings, English

Upper bounds on the error probability for the ensemble of linear block codes with mismatched decoding
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
Proc. of 2020 Int. Symposium on Information Theory and its Applications (ISITA2020), 151-155, 24 Oct. 2020, Peer-reviwed, In this paper, applying the technique of the DS2 bound, we derive an upper bound on the error probability of mismatched decoding with the ensemble of linear block codes, which was defined by Hof, Sason and Shamai. Assuming the ensemble of random linear block codes defined by Gallager, we show that the obtained bound is not looser than the conventional bound.
International conference proceedings, English

Optimum source resolvability rate with respect to f-divergences using the smooth Rényi entropy
Ryo Nomura; Hideki Yagi
Proc. of 2020 IEEE Int. Symposium on Information Theory (ISIT2020), IEEE, 2286-2291, 21 Jun. 2020, Peer-reviwed
International conference proceedings, English

Binary codeword table for multilevel document classification using information theoretic criterion
Gendo Kumoi; Hideki Yagi; Masayuki Goto; Shigeichi Hirasawa
IPSJ Trans. Mathematical Modeling and Its Applications, IPSJ, 13, 11, 1-12, 25 Mar. 2020, Peer-reviwed
Scientific journal, Japanese

A new characterization of the capacity region of identification system under noisy enrollment
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 54th Annual Conference on Information Sciences and Systems (CISS2020), IEEE, 1, 18 Mar. 2020, Peer-reviwed
International conference proceedings, English

The minimum cost of information erasure for stationary memoryless sources under restriction on the output distribution
Naruaki Amada; Hideki Yagi
Last, Proc. of 54th Annual Conference on Information Sciences and Systems (CISS2020), IEEE, 1, 18 Mar. 2020, Peer-reviwed
International conference proceedings, English

The Shannon cipher system with causal disclosure over separate noisy channel
Qipeng Wu; Hideki Yagi
Last, Proc. of 2020 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2020), 543-546, 29 Feb. 2020, Peer-reviwed
International conference proceedings, English

Sum-capacity region of a multi-enrollment rate-constrained system using PUF observations
Lingyun Chen; Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2020 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2020), 547-550, 29 Feb. 2020, Peer-reviwed
International conference proceedings, English

Decision feedback scheme with criterion LR+Th for the ensemble of linear block codes
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
IEICE Trans. Fundamentals, The Institute of Electronics, Information and Communication Engineers, 103, 1, 334-345, Jan. 2020, Peer-reviwed,

In decision feedback scheme, Forney's decision criterion (Forney's rule: FR) is optimal in the sense that the Neyman-Pearson's lemma is satisfied. Another prominent criterion called LR+Th was proposed by Hashimoto. Although LR+Th is suboptimal, its error exponent is shown to be asymptotically equivalent to that of FR by random coding arguments. In this paper, applying the technique of the DS2 bound, we derive an upper bound for the error probability of LR+Th for the ensemble of linear block codes. Then we can observe the new bound from two significant points of view. First, since the DS2 type bound can be expressed by the average weight distribution whose code length is finite, we can compare the error probability of FR with that of LR+Th for the fixed-length code. Second, the new bound elucidates the relation between the random coding exponents of block codes and those of linear block codes.

Scientific journal, English

Optimum overflow thresholds in variable-length source coding allowing non-vanishing error probability
Ryo Nomura; Hideki Yagi
IEEE Trans. Information Theory, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 65, 12, 8213-8221, 01 Dec. 2019, Peer-reviwed, The variable-length source coding problem allowing the error probability up to some constant is considered for general sources. In this problem, the optimum mean codeword length of variable-length codes has already been determined. On the other hand, in this paper, we focus on the overflow (or excess codeword length) probability instead of the mean codeword length. The infimum of overflow thresholds under the constraint that both of the error probability and the overflow probability are smaller than or equal to some constant is called the optimum overflow threshold. In this paper, we first derive finite-length upper and lower bounds on these probabilities so as to analyze the optimum overflow thresholds. Then, by using these bounds, we determine the general formula of the optimum overflow thresholds in both of the first-order and second-order forms. Next, we consider another expression of the derived general formula so as to reveal the relationship with the optimum coding rate in the fixed-length source coding problem. Finally, we apply the general formula derived in this paper to the case of stationary memoryless sources.
Scientific journal, English

System evaluation of ternary error-correcting output codes for multiclass classification problems
Shigeichi Hirasawa; Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Tetsuya Sakai; Hiroshige Inazumi
Proc. of 2019 IEEE Int. Conference on Systems, Man and Cybernetics (SMC2019), IEEE, Oct. 2019, Peer-reviwed
International conference proceedings

Identification, secrecy, template, and privacy-leakage of biometric identification system under noisy enrollment
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2019 IEEE Int. Symposium on Information Theory (ISIT2019), IEEE, 812-816, 07 Jul. 2019, Peer-reviwed
International conference proceedings, English

On the capacity region of an SRAM-PUF 2-enrollment rate-constrained system without cell-permutation symmetry
Lingyun Chen; Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2019 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2019), 52-55, 04 Mar. 2019, Peer-reviwed
International conference proceedings, English

Exponential error bounds and decoding complexity for block codes constructed by unit memory trellis codes of branch length two
Shigeichi Hirasawa; Hideki Yagi; Manabu Kobayashi; Masao Kasahara
Proc. of 53th Annual Conference on Information Sciences and Systems (CISS2019), IEEE, 1-6, Mar. 2019, Peer-reviwed
International conference proceedings, English

Construction of locally repairable codes with multiple localities based on encoding polynomial
Tomoya Hamada; Hideki Yagi
Last, IEICE Trans. Fundamentals, E101-A, 12, 2047-2054, 01 Dec. 2018, Peer-reviwed
Scientific journal, English

Fundamental tradeoff among identification, secrecy and compression rates in biometric identification system
Vamoua Yachongka; Hideki Yagi
Last, Journal of Signal Processing, 22, 6, 337-342, 01 Nov. 2018, Peer-reviwed
Scientific journal, English

Decision feedback scheme with criterion LR+Th for the ensemble of linear block codes
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
Proc. of 2018 Int. Symposium on Information Theory and its Applications (ISITA2018), IEEE, 261-265, 28 Oct. 2018, Peer-reviwed
International conference proceedings, English

New results on variable-length lossy compression allowing positive overflow and excess distortion probabilities
Shota Saito; Hideki Yagi; Toshiyasu Matsushima
Proc. of 2018 Int. Symposium on Information Theory and its Applications (ISITA2018), 359-363, 28 Oct. 2018, Peer-reviwed
International conference proceedings, English

Overflow probability of codeword cost in variable-length coding problem allowing non-vanishing error probability
Ryo Nomura; Hideki Yagi
Proc. of 2018 Int. Symposium on Information Theory and its Applications (ISITA2018), IEEE, 364-368, 28 Oct. 2018, Peer-reviwed, The variable-length source coding with unequal cost allowing error probability is considered for general sources. In this setting, the first-and second-order optimum mean codeword cost have already been determined. On the other hand, we focus on the overflow probability of codeword cost and determine the general formulas of the first-and second-order optimum achievable overflow threshold. We also apply our general formulas to the stationary memoryless source.
International conference proceedings, English

A new bound of (r,\delta)-locally repairable codes over finite field of small order
Tomoya Hamada; Hideki Yagi
Last, Proc. of 2018 Int. Symposium on Information Theory and its Applications (ISITA2018), 504, 28 Oct. 2018, Peer-reviwed
International conference proceedings, English

Fundamental trade-off among identification, secrecy and template rates in identification system
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2018 Int. Symposium on Information Theory and its Applications (ISITA2018), 507, 28 Oct. 2018, Peer-reviwed
International conference proceedings, English

On the DS2 bound for Forney's generalized decoding using non-binary linear block codes
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
IEICE Trans. Fundamentals, E101-A, 8, 1223-1234, 01 Aug. 2018, Peer-reviwed, Recently, Hof et al. extended the type-2 Duman and Salehi (DS2) bound to generalized decoding, which was introduced by Forney, with decision criterion FR. From this bound, they derived two significant bounds. One is the Shulman-Feder bound for generalized decoding (GD) with the binary-input output-symmetric channel. The other is an upper bound for an ensemble of linear block codes, by applying the average complete weight distribution directly to the DS2 bound for GD. For the Shulman-Feder bound for GD, the authors derived a condition under which an upper bound is minimized at an intermediate step and show that this condition yields a new bound which is tighter than Hof et al.’s bound. In this paper, we first extend this result for non-binary linear block codes used over a class of symmetric channels called the regular channel. Next, we derive a new tighter bound for an ensemble of linear block codes, which is based on the average weight distribution.
Scientific journal, English

A greedy construction approach of codeword table on error correcting output coding for multivalued classification and its evaluation by using artificial data
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
Proc. of 2018 Int. Conf. on Engineering, Technology, and Applied Sciences (ICETA2018), 15-22, 25 Jun. 2018, Peer-reviwed
International conference proceedings, English

Variable-length resolvability for mixed sources and its application to variable-length source coding
Hideki Yagi; Te Sun Han
Lead, Proc. of 2018 IEEE Int. Symposium on Information Theory (ISIT2018), IEEE, 2391-2396, 22 Jun. 2018, Peer-reviwed
International conference proceedings, English

Variable-length channel resolvability for discrete memoryless sources and channels
Hideki Yagi; Te Sun Han
Lead, Proc. of 2018 IEEE Int. Symposium on Information Theory (ISIT2018), IEEE, 2047-2051, 21 Jun. 2018, Peer-reviwed
International conference proceedings, English

Overflow probability of variable-length codes allowing non-vanishing error probability
Ryo Nomura; Hideki Yagi
Proc. of 2018 IEEE Int. Symposium on Information Theory (ISIT2018), Institute of Electrical and Electronics Engineers Inc., 589-593, Jun. 2018, Peer-reviwed, The variable-length coding problem allowing the error probability up to some constant is considered for general sources. In this problem, we focus on the overflow (or excess codeword length) probability We also consider another expression of our general formula so as to reveal the relationship with the optimum coding rate in the fixed-length source coding problem.
International conference proceedings, English

Fundamental tradeoff among identification, secrecy and compression rates in biometric identification system
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2018 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2018), 5-8, 04 Mar. 2018, Peer-reviwed
International conference proceedings, English

Construction of locally repairable codes with multiple localities based on encoding polynomial
Tomoya Hamada; Hideki Yagi
Last, Proc. of 2018 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2018), 627-630, 04 Mar. 2018, Peer-reviwed
International conference proceedings, English

Polar codes achieving strong secrecy for broadcast channel with confidential messages
Takahiro Fujita; Hideki Yagi
Last, Proc. of 2018 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2018), 631-634, 04 Mar. 2018, Peer-reviwed
International conference proceedings, English

A simple proof of polarization for memoryless sources with and without side information
Yuming Yang; Hideki Yagi
Last, Proc. of 2018 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2018), 635-638, 04 Mar. 2018, Peer-reviwed
International conference proceedings, English

Variable-length coding with cost allowing non-vanishing error probability
Hideki Yagi; Ryo Nomura
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E100A, 8, 1683-1692, Aug. 2017, Peer-reviwed, We consider fixed-to-variable length coding with a regular cost function by allowing the error probability up to any constant epsilon. We first derive finite-length upper and lower bounds on the average codeword cost, which are used to derive general formulas of two kinds of minimum achievable rates. For a fixed-to-variable length code, we call the set of source sequences that can be decoded without error the dominant set of source sequences. For any two regular cost functions, it is revealed that the dominant set of source sequences for a code attaining the minimum achievable rate under a cost function is also the dominant set for a code attaining the minimum achievable rate under the other cost function. We also give general formulas of the second-order minimum achievable rates.
Scientific journal, English

Generalized construction of cyclic (r, t)-locally repairable codes using trace function
Quang Thanh Pham; Hideki Yagi
Last, IEICE Communications Express, 6, 7, 449-453, 01 Jul. 2017, Peer-reviwed
Scientific journal, English

Variable-length lossy compression allowing positive overflow and excess distortion probabilities
Shota Saito; Hideki Yagi; Toshiyasu Matsushima
Proc. of 2017 IEEE Int. Symposium on Information Theory (ISIT2017), IEEE, 1568-1572, 25 Jun. 2017, Peer-reviwed
International conference proceedings, English

Variable-length resolvability for general sources
Hideki Yagi; Te Sun Han
Lead, Proc. of 2017 IEEE Int. Symposium on Information Theory (ISIT2017), IEEE, 1748-1752, 25 Jun. 2017, Peer-reviwed
International conference proceedings, English

Single-bit quantization of binary-input, continuous-output channels
Brian M. Kurkoski; Hideki Yagi
Proc. of 2017 IEEE Int. Symposium on Information Theory (ISIT2017), IEEE, 2088-2092, 25 Jun. 2017, Peer-reviwed
International conference proceedings, English

Channel resolvability theorems for general sources and channels
Hideki Yagi
Lead, Proc. of 2017 IEEE Int. Symposium on Information Theory (ISIT2017), IEEE, 2746-2750, 25 Jun. 2017, Peer-reviwed
International conference proceedings, English

Reliability function and strong converse of biometrical identification systems based on list-decoding
Vamoua Yachongka; Hideki Yagi
Last, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E100A, 5, 1262-1266, May 2017, Peer-reviwed, The biometrical identification system, introduced by Willems et al., is a system to identify individuals based on their measurable physical characteristics. Willems et al. characterized the identification capacity of a discrete memoryless biometrical identification system from information theoretic perspectives. Recently, Mori et al. have extended this scenario to list-decoding whose list size is an exponential function of the data length. However, as the data length increases, how the maximum identification error probability (IEP) behaves for a given rate has not yet been characterized for list-decoding. In this letter, we investigate the reliability function of the system under fixed-size list-decoding, which is the optimal exponential behavior of the maximum IEP. We then use Arimoto's argument to analyze a lower bound on the maximum IEP with list-decoding when the rate exceeds the capacity, which leads to the strong converse theorem. All results are derived under the condition that an unknown individual need not be uniformly distributed and the identification process is done without the knowledge of the prior distribution.
Scientific journal, English

Lattice codes for Gaussian broadcast channel with a common message
Yuki Yoshioka; Hideki Yagi
Last, Proc. of 2017 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2017), 565-568, 03 Mar. 2017, Peer-reviwed
International conference proceedings, English

Capacity region of Gaussian bidirectional broadcast channel with common and confidential messages
Akinori Inaba; Hideki Yagi
Last, Proc. of 2017 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2017), 193-196, 28 Feb. 2017, Peer-reviwed
International conference proceedings, English

Variable-length coding with cost allowing non-vanishing error probability
Hideki Yagi; Ryo Nomura
Lead, Proc. of 2016 Int. Symposium on Information Theory and its Applications (ISITA2016), IEEE, 16-20, Oct. 2016, Peer-reviwed, We derive a general formula of the minimum achievable rate for fixed-to-variable length coding with a regular cost function by allowing the error probability up to a constant. E. For a fixed-to-variable length code, we call the set of source sequences that can be decoded without error the dominant set of source sequences. For any two regular cost functions, it is revealed that the dominant set of source sequences for a code attaining the minimum achievable rate with a cost function is also the dominant set for a code attaining the minimum achievable rate with the other cost function. We also give a general formula of the second-order minimum achievable rate.
International conference proceedings, English

Theory of Information Spectrum
Hideki Yagi
Sugaku Seminar, Nihon Hyoronsha, 55, 8, 14-19, 01 Aug. 2016, Invited
Japanese

First- and second-order coding theorems for mixed memoryless channels with general mixture
Hideki Yagi; Te Sun Han; Ryo Nomura
Lead, IEEE Trans. Inf. Theory, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 62, 8, 4395-4412, Aug. 2016, Peer-reviwed, This paper investigates the first-and second-order maximum achievable rates of codes with/without cost constraints for mixed channels whose channel law is characterized by a general mixture of (at most) uncountably many stationary and memoryless discrete channels. These channels are referred to as mixed memoryless channels with general mixture and include the class of mixed memoryless channels of finitely or countably memoryless channels as a special case. For the mixed memoryless channels with general mixture, the first-order coding theorem which gives a formula for the e-capacity is established, and then a direct part of the second-order coding theorem is provided. A subclass of mixed memoryless channels whose component channels can be ordered according to their capacity is introduced, and the first-and second-order coding theorems are established. It is shown that the established formulas reduce to several known formulas for restricted scenarios.
Scientific journal, English

Variable-length lossy source coding allowing some probability of union of overflow and excess distortion
Ryo Nomura; Hideki Yagi
Proc. of 2016 IEEE Int. Symposium on Information Theory (ISIT2016), IEEE, 2958-2962, Jul. 2016, Peer-reviwed, We consider a new concept of achievability in the variable-length lossy source coding on the basis of the probability of the union of the overflow of codeword length and the excess distortion. In this setting, our main concern is to determine the achievable rate-distortion region for a given source and distortion measure. To this end, we first derive non-asymptotic upper and lower bounds, and then we derive general formulas of this achievable rate-distortion region in the first- and second-order sense. Finally, we apply our general formulas to stationary memoryless sources with an additive distortion measure.
International conference proceedings, English

Reliability function and strong converse of biometrical identification systems
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2016 IEEE Int. Symposium on Information Theory (ISIT2016), IEEE, 547-551, Jul. 2016, Peer-reviwed, The biometrical identification system, introduced by Willems et al., is a system to identify individuals based on measurable physical characteristics of each individual. One of the most important factors on this system is the identification capacity, i.e. the maximum achievable rate of the number of individuals that can be distinguished with a vanishing error probability asymptotically. Willems et al. have made clear that the identification capacity of a discrete memoryless system can be characterized from an information theoretic perspective. Recently, Mori et al. have extended this scenario and characterized the identification capacity under list-decoding whose list size is an exponential function of the data length. However, as the length of biometrical data sequences increases, how the maximum identification error probability of the system behaves; that is, how fast it decreases for a given rate, has not yet been discussed.
In this paper, we first use Arimoto's argument to analyze a lower bound on the error probability, which leads to the proof of the strong converse theorem when each individual is not uniformly distributed and the identification process is done without the knowledge of the prior distribution. We then investigate the reliability function of the system under fixed-size list-decoding, which is the optimal exponential behavior of the maximum identification error probability, and it is shown that the reliability function behaves like the well-known random coding error exponent.
International conference proceedings, English

Reliability function of discrete memoryless biometrical identification systems
Vamoua Yachongka; Hideki Yagi
Last, Proc. of 2016 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2016), 61-64, 07 Mar. 2016, Peer-reviwed
International conference proceedings, English

On derivation of tighter Shulman-Feder bound for Forney's generalized decoding
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
IEICE Trans. on Fumdamentals, IEICE, J98-A, 12, 680-690, 01 Dec. 2015, Peer-reviwed
Scientific journal, Japanese

First- and second-order coding theorems for mixed memoryless channels with general mixture
Hideki Yagi; Te Sun Han; Ryo Nomura
Lead, Proc. of 2015 IEEE Int. Symposium on Information Theory (ISIT2015), IEEE, 2969-2973, Jun. 2015, Peer-reviwed, This paper studies the first- and second-order maximum achievable rates of codes with/without cost constraints for general mixed channels whose channel law is characterized by a mixture of uncountably many stationary and memoryless discrete channels. These channels are referred to as general mixed memoryless channels and include mixed memoryless channels of finitely or countably many memoryless channels as a special case. For general mixed memoryless channels, the first-order coding theorem which gives a formula for the epsilon-capacity is established, and then a direct part of the second-order coding theorem is provided. A subclass of general mixed memoryless channels whose component channels can be ordered according to their capacity is introduced, and the first- and second-order coding theorems are established. It is shown that the established formulas reduce to several known formulas for restricted scenarios.
International conference proceedings, English

Variable-length coding with epsilon-fidelity criteria for general sources
Hideki Yagi; Ryo Nomura
Lead, Proc. of 2015 IEEE Int. Symposium on Information Theory (ISIT2015), IEEE, 2181-2185, Jun. 2015, Peer-reviwed, This paper addresses two problems of variable length coding with a fidelity criterion for general sources, in which either the probability of codeword length overflow or that of excess distortion for a given threshold is allowed up to epsilon. In each problem, a general formula for the achievable region of coding rates and distortion levels is established via information spectrum methods. It is shown that there is a tight connection between the two problems, and the achievable regions are the same under a mild condition on the distortion measure. As a consequence, it turns out that superficially different general formulas for the two coding problems coincide with each other.
International conference proceedings, English

Information spectrum approach to fixed-length lossy source coding problem with some excess distortion probability
Ryo Nomura; Hideki Yagi
Proc. of 2015 IEEE Int. Symposium on Information Theory (ISIT2015), IEEE, 306-310, Jun. 2015, Peer-reviwed, This paper deals with a fixed-length lossy source coding problem with some excess distortion probability called the source coding problem with epsilon-fidelity criterion. In this problem, the rate-distortion function and the distortion-rate function have already been characterized for i.i.d. sources with an additive distortion measure in the sense of first-order and second-order coding rates. However, general formulas for these functions have not been revealed up to present. Hence, in this paper we derive general formulas for the rate-distortion function and the distortion-rate function with the epsilon-fidelity criterion in both of the first-order and second-order cases. A relationship between our general formulas and previous results are also discussed.
International conference proceedings, English

Channel dispersion for well-ordered mixed channels decomposed into memoryless channels
Hideki Yagi; Ryo Nomura
Lead, Proc. of 2014 Int. Symposium on Information Theory and its Applications (ISITA2014), IEEE, 35-39, Oct. 2014, Peer-reviwed, For a class of mixed channels that are decomposed into finitely many stationary memoryless channels, the optimum second-order coding rate, or equivalently, channel dispersion, is derived. The addressed channel, which is an instance of non-ergodic channels, is a sub-class of regular decomposable channels introduced by Winkelbauer. The second-order coding theorem can be viewed as an extension of the coding theorem established by Polyanskiy, Poor, and Verdu for the mixed channel of finitely many binary symmetric channels.
International conference proceedings, English

Write-once memory codes for low-complexity decoding of asymmetric multiple access channel
Ryota Sekiya; Erick C. G. Alvarez; Brian M. Kurkoski; Hideki Yagi
Proc. of 2014 Int. Symposium on Information Theory and its Applications (ISITA2014), IEEE, 623-627, Oct. 2014, Peer-reviwed, Write-Once Memory (WOM) codes are designed for data storage, which allow re-writing on n cells that can change their bit value from 0 to 1 but not vice versa. This paper focuses on applying "WOM codes" to cooperative wireless communications. Due to the characteristics of WOM codes, the Asymmetric Multiple Access Channel (AMAC) (also referred to as the MAC with degraded messages) is considered, which is a conventional Multiple Access Channel (MAC), where one user can observe the other user's message. We describe an AMAC system where WOM codes are used to deal with the interference between two users. For a specific AMAC model, WOM codes can achieve the AMAC capacity, and using WOM codes for the AMAC with no errors leads to a low-complexity decoder. Finally, we comment of how the AMAC model can be applied to the relay channel. While we consider primarily the AMAC with no errors, this study forms a foundation for future work on the AMAC with errors.
International conference proceedings, English

Quantization of binary-input discrete memoryless channels
Brian M. Kurkoski; Hideki Yagi
IEEE Trans. Inf. Theory, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 60, 8, 4544-4552, Aug. 2014, Peer-reviwed, The quantization of the output of a binary-input discrete memoryless channel to a smaller number of levels is considered. An algorithm, which finds an optimal quantizer, in the sense of maximizing mutual information between the channel input and quantizer output is given. This result holds for arbitrary channels, in contrast to previous results for restricted channels or a restricted number of quantizer outputs. In the worst case, the algorithm complexity is cubic M-3 in the number of channel outputs M. Optimality is proved using the theorem of Burshtein, Della Pietra, Kanevsky, and Nadas for mappings, which minimize average impurity for classification and regression trees.
Scientific journal, English

Single-letter characterization of epsilon-capacity for mixed memoryless channels
Hideki Yagi; Ryo Nomura
Lead, Proc. of 2014 IEEE Int. Symposium on Information Theory (ISIT2014), IEEE, 2874-2878, Jun. 2014, Peer-reviwed, For the class of mixed channels decomposed into stationary memoryless channels, single-letter characterizations of the epsilon-capacity have not been known except for restricted classes of channels such as the regular decomposable channel introduced by Winkelbauer. This paper gives single-letter characterizations of epsilon-capacity for mixed channels decomposed into at most countably many memoryless channels with a finite input alphabet with/without cost constraints. It is shown that the given characterization reduces to the one for the channel capacity given by Ahlswede when epsilon is zero. Some properties of the function of the epsilon-capacity are analyzed.
International conference proceedings, English

Bounds on maximum likelihood decoding performance for linear codes at low rates
Hideki Yagi; H. Vincent Poor
Lead, IEEE Trans. Inf. Theory, Institute of Electrical and Electronics Engineers Inc., 59, 7, 4482-4497, Jul. 2013, Peer-reviwed, For a given linear code (ensemble), upper bounds on the error probability under maximum likelihood decoding are investigated at low rates. A class of symmetric memoryless channels suitable for Bhattacharyya-type bounds, which are particularly of importance at low rates, is introduced. Over a symmetric channel, a lower bound on the error exponent is derived for a given linear code. A sufficient condition for achieving the expurgated exponent, which is the best among known error exponents at low rates, within a fixed discrepancy is given. Over a general discrete memoryless channel, the same analysis provides a lower bound on the average error exponent for an ensemble of coset codes generated by a given linear code. The bounding technique is extended to the case of generalized maximum likelihood decoding with erasure and list-decoding options. © 2013 IEEE.
Scientific journal, English

Analysis on the fingerprinting capacity for memoryless and fair collusion attacks
Tomoya Narita; Hideki Yagi; Tsutomu Kawabata
Proc. of 2013 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP2013), 1, Mar. 2013, Peer-reviwed
International conference proceedings, English

Finite blocklength bounds for multiple access channels with correlated sources
Hideki Yagi
Proc. of 2012 Int. Symposium on Information Theory and its Applications (ISITA2012), IEEE, 377-381, Oct. 2012, Peer-reviwed, Refined bounds on the probability of decoding error for arbitrary multiple-access channels with correlated sources are derived. The contribution of this paper is to give new upper bounds on the probability of decoding error for any given blocklength. These bounds can be used for the analysis over any multiple-access channels with correlated and uncorrelated sources in the finite blocklength regime. It is shown that the derived bounds can recover previously known bounds for the multiple access channel with correlated and uncorrelated sources.
International conference proceedings, English

Finding the capacity of a quantized binary-input DMC
Brian M. Kurkoski; Hideki Yagi
Proc. of 2012 IEEE Int. Symposium on Information Theory (ISIT2012), IEEE, 686-690, Jul. 2012, Peer-reviwed, Consider a binary-input, M-output discrete memoryless channel (DMC) where the outputs are quantized to K levels, with K < M. The subject of this paper is the maximization of mutual information between the input and quantizer output, over both the input distribution and channel quantizer. This can be regarded as finding the capacity of a quantized DMC. An algorithm is given, which either finds the optimal input distribution and corresponding quantizer, or declares a failure.
International conference proceedings, English

Channel quantizers that maximize random coding exponents for binary-input memoryless channels
Hideki Yagi; Brian M. Kurkoski
Lead, Proc. of 2012 IEEE Int. Conference on Communications (ICC2012), IEEE, 2228-2232, Jun. 2012, Peer-reviwed, The problem of finding the optimum output quantizer for a given discrete memoryless channel is investigated, where the quantizer output has fewer values than the channel output. While mutual information has received attention as an objective function for optimization, the focus of this paper is use of the random coding exponent, which was originally derived by Gallager, as criteria. Two problems are addressed, where one problem is a partial problem of the other. The main result is a quantizer design algorithm, and a proof that it finds the optimum quantizer in the partial problem. The quantizer design algorithm is based on a dynamic programming approach, and is an extension of a mutual-information maximization method. For the binary-input case, it is shown that the optimum quantizer can be found with complexity that is polynomial in the number of channel outputs.
International conference proceedings, English

On the capacity of fingerprinting codes against AND, averaging, and related attacks
Gou Hosoya; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Journal of Information Assurance and Security, 7, 41-51, May 2012, Peer-reviwed
Scientific journal, English

Polynomial-time codes against averaging attack for multimedia fingerprinting
Hideki Yagi; Tsutomu Kawabata
Lead, Multimedia - A Multidisciplinary Approach to Complex Issues (I. Karydis, Eds), 125-140, Mar. 2012, Peer-reviwed
Research society, English

On the capacity of fingerprinting codes against unknown size of colluders
Gou Hosoya; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Proc. of the 7th Int. Conference on Information Assurance and Security (IAS2011), 234-239, Dec. 2011, Peer-reviwed, In this paper, a new attack model in which the number of colluders are distributed according to a certain probability distribution is introduced. Two classes of collusion attacks which include well-known collusion attacks in the context of multimedia fingerprinting are provided. For these two attack classes, achievable rates for the unknown size of the actual colluders are derived. Based on the derived achievable rates, achieve rates for some particular attacks are investigated. For the AND attack, the bound derived in this paper coincides with the previous known bound, although the attack model in this paper does not assume that the decoder knows the actual number of colluders. Moreover, for the averaging attack, it is clarified that derived achievable rate is larger than previously known bound with random linear codes. © 2011 IEEE.
International conference proceedings, English

Improved rate-equivocation regions for secure cooperative communication
Ninoslav Marina; Hideki Yagi; H. Vincent Poor
Proc. of 2011 IEEE Int. Symposium on Information Theory (ISIT2011), IEEE, 2871-2875, Jul. 2011, Peer-reviwed, A simple four node network in which cooperation improves the information-theoretic secrecy is studied. The channel consists of two senders, a receiver, and an eavesdropper. One or both senders transmit confidential messages to the receiver, while the eavesdropper tries to decode the transmitted message. The main result is the derivation of a newly achievable rate-equivocation region that is shown to be larger than a rate-equivocation region derived by Lai and El Gamal for the relay-eavesdropper channel. When the rate of the helping interferer is zero, the new rate-equivocation region reduces to the capacity-equivocation region over the wire-tap channel; hence, the new achievability scheme can be seen as a generalization of a coding scheme proposed by Csiszar and Korner.
International conference proceedings, English

Coset codes for compound multiple access channels with common information
Hideki Yagi; H. Vincent Poor
Lead, IEEE Trans. Inf. Theory, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 57, 6, 3429-3448, Jun. 2011, Peer-reviwed, Code construction is considered for arbitrary discrete memoryless compound multiple access channels (MACs) with common information. This class of channels includes MACs with/without common messages or with partially cooperating encoders. A construction method of code ensembles based on coset codes is proposed for these channels. Assuming joint maximum likelihood decoding, the performance of the proposed code ensemble is analyzed by deriving a lower bound on error exponents. A condition assuring that codes achieve the capacity region on average is given. It is seen that an elaborate combination of good linear codes gives capacity achieving codes for compound MACs with common messages or with partially cooperating encoders. The use of restricted ensembles with low-density parity check (LDPC) codes as component codes is also discussed. It is shown that a coset code ensemble based on nonbinary regular LDPC codes approaches the random coding exponent, and thus is capacity-achieving.
Scientific journal, English

Quantization of Binary-Input Discrete Memoryless Channels, with Applications to LDPC Decoding
Brian M. Kurkoski; Hideki Yagi
CoRR, abs/1107.5637, 2011, Peer-reviwed

Polynomial-time decodable codes for multiple access channels
Hideki Yagi; H. Vincent Poor
Lead, IEEE Commun. Letters, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 15, 1, 73-75, Jan. 2011, Peer-reviwed, A construction of polynomial-time decodable codes for discrete memoryless multiple access channels (MACs) is proposed based on concatenated codes. Concatenated codes, originally developed by Forney, can achieve any rate below capacity for the single-user discrete memoryless channel while requiring only polynomial-time decoding complexity in the code length. In this letter, Forney's construction together with multi-level concatenation is generalized to MACs. An error exponent for the constructed code is derived, and it is shown that the constructed code can achieve any rate in the capacity region.
Scientific journal, English

An iterative decoding algorithm for rate-compatible punctured low-density parity-check codes of high coding rates
Gou Hosoya; Hideki Yagi; Manabu Kobayashi
Proc. of 2010 Int. Symposium on Information Theory and Its Applications (ISITA2010), 394-399, Oct. 2010, Peer-reviwed, An iterative decoding algorithm of rate-compatible punctured low-density parity-check (RCP-LDPC) codes of high coding rates is developed. This algorithm performs a predetermined recovering process of punctured bits sums at the beginning of each iteration of the standard belief-propagation (BP) decoding algorithm. By propagating messages of two punctured bits sum, this algorithm can recover much more punctured bits than the standard BP decoding algorithm. It is shown that the proposed algorithm is applicable for RCP-LDPC codes of higher coding rates with little increase of decoding complexity. © 2010 IEEE.
International conference proceedings, English

An explicit construction of concatenated codes for multiple access channels
Hideki Yagi; H. Vincent Poor
Lead, Proc. of 48th Annual Allerton Conference on Communication, Control, and Computing, 466-473, Sep. 2010, Peer-reviwed, Recently, a construction of polynomial-time decodable codes for discrete memoryless multiple access channels (MACs) has been proposed based on multi-level concatenated coding. This paper provides several refinements to concatenated codes for MACs. First, an explicit construction of inner codes is devised based on an ensemble of affine codes so that no search for good inner codes that achieve the capacity region is needed. Then a new decoding algorithm is proposed in which the inner decoding and the outer decoding alternate to improve a lower bound on the error exponent. It is shown that the proposed codes still arbitrarily approach every interior point of the capacity region for a given MAC with polynomial-time decoding complexity. ©2010 IEEE.
International conference proceedings, English

Performance analysis of linear codes under maximum likelihood decoding at low rates
Hideki Yagi; H. Vincent Poor
Lead, Proc. of 2010 IEEE Int. Symposium on Information Theory (ISIT2010), IEEE, 1168-1172, Jun. 2010, Peer-reviwed, or a given linear code, a lower bound on the error exponent under maximum likelihood decoding is investigated at low rates. or a given linear code, a lower bound on the error exponent under maximum likelihood decoding is investigated at low rates. F In the analysis of the decoding error probability, it is important to characterize the error exponent, since it indicates how fast the probability of decoding error converges to zero asymptotically. Over a symmetric memoryless channel, an error exponent is derived for a given linear code. A sufficient condition for achieving the expurgated exponent, which is the best among known error exponents at low rates, is given. Over a general discrete memoryless channel, the same analysis shows the expected error exponent of an ensemble of coset codes generated by a given linear code.
International conference proceedings, English

Coset codes for multiple access channels with common information based on LDPC codes
Hideki Yagi; H. Vincent Poor
Proc. of 2010 IEEE Int. Symposium on Information Theory (ISIT2010), IEEE, 475-479, Jun. 2010, Peer-reviwed, Coding for discrete memoryless compound multiple access channels (MACs) with common information is considered. A construction method for an ensemble of MAC codes is proposed based on non-binary low-density parity check (LDPC) codes. It is shown that an overall MAC code asymptotically approaches the random coding exponent for the compound MAC with common information under joint maximum likelihood decoding. The analysis of decoding error probability shows that several regular LDPC codes which are good for a single-user channel are sufficient for achieving the random coding exponent or the capacity region for this channel.
International conference proceedings, English

Closest point algorithms with l(p) norm for root lattices
Kenichirou Takizawa; Hideki Yagi; Tsutomu Kawabata
Proc. of 2010 IEEE Int. Symposium on Information Theory (ISIT2010), IEEE, 1042-1046, Jun. 2010, Peer-reviwed, We study quantizers with l(p) norm, with p >= 1, for the root lattices. Our algorithms extend the ones proposed by Conway and Sloane [1] with l(2) norm. They proposed an interesting algorithm for A(n) lattice, but without proof of the optimality. We give the proof of the optimality with our extended case of l(p) norm. We also give an algorithm for E(6) and its dual, which are not described in [1].
International conference proceedings, English

Nearest point algorithms for root lattices under norm lp
Kenitirou Takizawa; Hideki Yagi; Tsutomu Kawabata
IEICE Trans. Fundamentals (in Japanese), The Institute of Electronics, Information and Communication Engineers, J93-A, 4, 289-299, Apr. 2010, Peer-reviwed, 本論文では,ルート格子に対するl_pノルムによる最適量子化アルゴリズムを考える.先に,ConwayとSloaneはルート格子に対して,l_2ノルムによる最適量子化アルゴリズムを提案した.しかしながら,そのアルゴリズムの最適性は証明されていない.そこで本論文では,l_pノルムを用いた場合も含めて,アルゴリズムの最適性を示す.また,従来与えられていなかった格子E_6並びにその双対格子E^*_6に対する量子化アルゴリズムを提案し,l_pノルムを用いたときに最適となることを示す.
Scientific journal, Japanese

Concatenation of a discrete memoryless channel and a quantizer
Brian M. Kurkoski; Hideki Yagi
Proc. of 2010 IEEE Information Theory Workshop (ITW2010), Jan. 2010, Peer-reviwed, The concatenation of an arbitrary discrete memoryless channel with binary input followed by a quantizer is considered. For a restricted quantizer alphabet size, it is shown that the maximum of the mutual information between the channel input and the quantizer output can be found by dynamic programming. Numerical examples are given to illustrate the results. This problem is shown to be an example of concave programming.
International conference proceedings, English

Locally optimal message quantization for binary LDPC decoding
Brian Kurkoski; Hideki Yagi
Proc. of 2010 IEEE Information Theory Workshop (ITW2010), Jan. 2010, Peer-reviwed
International conference proceedings, English

Polynomial-time decodable fingerprinting codes for multimedia
Hideki Yagi
Lead, Proc. of 2009 Mosharaka Int. Conf. on Communications, Networking and Information Technology (MIC-CNIT2009), 100-105, Dec. 2009, Peer-reviwed
International conference proceedings, English

Adaptive decoding algorithms for low-density parity-check codes over the binary erasure channel
Gou Hosoya; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E92A, 10, 2418-2430, Oct. 2009, Peer-reviwed, Two decoding procedures combined with a belief-propagation (BP) decoding algorithm for low-density parity-check codes over the binary erasure channel are presented. These algorithms continue a decoding procedure after the BP decoding algorithm terminates. We derive a condition that our decoding algorithms can correct an erased bit which is uncorrectable by the BP decoding algorithm. We show by simulation results that the performance of our decoding algorithms is enhanced compared with that of the BP decoding algorithm with little increase of the decoding complexity.
Scientific journal, English

Coset codes for compound multiple access channels with common information
Hideki Yagi; H. Vincent Poor
Lead, Proc. of 2009 IEEE Int. Symposium on Information Theory (ISIT2009), IEEE, 1854-1858, Jul. 2009, Peer-reviwed, This paper considers code construction for arbitrary discrete memoryless compound multiple access channels (MACs) with common information. This class of channels includes a MAC with/without common messages or with partially cooperating encoders. A construction method of code ensembles based on coset codes is proposed for these channels. Assuming joint maximum likelihood decoding, the performance of the proposed code ensemble is analyzed by deriving error exponents. A condition is shown such that codes achieve the capacity region on average. The result obtained here reduces to the result of Slepian and Wolf or other conventional works if restricted to a single MAC. A combination of good linear codes gives capacity achieving codes for compound MACs with common messages or with partially cooperating encoders.
International conference proceedings, English

Fingerprinting codes for multimedia data against averaging attack
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E92A, 1, 207-216, Jan. 2009, Peer-reviwed, Code construction for digital fingerprinting, which is a copyright protection technique for multimedia, is considered. Digital fingerprinting should deter collusion attacks, where several fingerprinted copies of the same content are mixed to disturb their fingerprints. In this paper, we consider the averaging attack, which is known to be effective for multimedia fingerprinting with the spread spectrum technique. We propose new methods tor constructing fingerprinting codes to increase the coding rate of conventional fingerprinting codes, while they guarantee to identify the same number of colluders. Due to the new fingerprinting codes, the system can deal with a larger number of users to supply digital contents.
Scientific journal, English

Random coding bounds for correlated parallel channels with unidirectionally cooperating decoders
Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Lead, Proc. of 2008 Int. Symposium on Information Theory and its Applications (ISITA2008), IEEE, 121-125, Dec. 2008, Peer-reviwed, We propose a maximum likelihood decoding scheme with decoder's partial cooperation, in which only unidirectional information passing is possible, for correlated parallel channels. We derive a bound on the probability of decoding error for the proposed scheme with a coset code ensemble by using randomized technique. From the property of the derived error exponent, we show a condition that the scheme achieves the capacity region. We compare the proposed scheme with other possible scheme with decoder's unidirectional cooperation.
International conference proceedings, English

An efficient design of irregular LDPC codes using beta approximation for the Gilbert-Elliott channel
Manabu Kobayashi; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Proc. of 2008 Int. Symposium on Information Theory and its Applications (ISITA2008), IEEE, 1543-1547, Dec. 2008, Peer-reviwed, In this paper, we investigate the design of low-density parity-check (LDPC) codes for the Gilbert-Elliott (GE) channel. Recently, Eckford et al. proposed a design method of irregular LDPC codes using approximate density-evolution (DE) for Markov channels [7]. In the design method proposed by Eckford et al., the probability density function (PDF) of the messages from variable nodes to check nodes is approximated by the Gaussian distribution. In this paper, we first show the method to obtain the accurate PDF of the messages from variable nodes to check nodes by utilizing two DE steps for the Gaussian distribution. We call this method the iterative density approximation (IDA). Using this method, we can design the good LDPC codes. Next, we propose an efficient design method of irregular LDPC codes by using Beta approximation to the PDF of the channel state probability for the GE channel. Consequently, we show that the complexity to calculate PDFs of the channel messages is considerably reduced though the rates of LDPC codes obtained by using the proposed approximation are almost the same as that of the IDA method.
International conference proceedings, English

Density evolution analysis of robustness for LDPC codes over the Gilbert-Elliott channel
Manabu Kobayashi; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E91A, 10, 2754-2764, Oct. 2008, Peer-reviwed, In this paper. we analyze the robustness for low-density parity-check (LDPC) codes over the Gilbert-Elliott (GE) channel. For this purpose we propose a density evolution method for the case where LDPC decoder uses the mismatched parameters for the GE channel. Using this method, we derive the region of tuples of true parameters and mismatched decoding parameters for the GE channel. where the decoding error probability approaches asymptotically to zero.
Scientific journal, English

A method for grouping symbol nodes of group shuffled BP decoding agorithm
Yoshiyuki Sato; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E91A, 10, 2745-2753, Oct. 2008, Peer-reviwed, In this paper, we propose a method for enhancing performance of a sequential version of the belief-propagation (BP) decoding algorithm, the group shuffled BP decoding algorithm for low-density parity-check (LDPC) codes. An improved BP decoding algorithm, called the shuffled BP decoding algorithm, decodes each symbol node in serial at each iteration. To reduce the decoding delay of the shuffled BP decoding algorithm, the group shuffled BP decoding algorithm divides all symbol nodes into several groups. In contrast to the original group shuffled BP, which automatically generates groups according to symbol positions, in this paper we propose a method for grouping symbol nodes which generates groups according to the structure of a Tanner graph of the codes. The proposed method can accelerate the convergence of the group shuffled BP algorithm and obtain a lower error rate in a small number of iterations. We show by simulation results that the decoding performance of the proposed method is improved compared with those of the shuffled BP decoding algorithm and the group shuffled BP decoding algorithm.
Scientific journal, English

Error control codes for parallel channel with correlated errors
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Proc. of 2008 IEEE Information Theory Workshop (ITW2008), IEEE, 421-425, May 2008, Peer-reviwed, This paper introduces two channel models of correlated parallel channels. Then we analyze structure of error correcting codes over these correlated parallel channels. We derive necessary and sufficient conditions for these codes and some code construction is presented. We also show some upper and lower bounds on the coding rate of the error correcting codes for correlated parallel channels. The introduced channel models are related to burst error channels and the codes analyzed in this paper can be used as asymmetric interleaving codes for burst error channels.
International conference proceedings, English

Improved collusion-secure codes for digital fingerprinting based on finite geometries
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Proc. of 2007 IEEE Int. Conference on Systems, Man, and Cybernetics (SMC2007), IEEE, 522-526, Oct. 2007, Peer-reviwed, Digital fingerprinting, a copyright protection technique for digital contents, is considered. Digital fingerprinting should deter collusion attacks, where several fingerprinted copies of the same content are mixed to disturb their fingerprints. In this paper, we consider the averaging attack, which has effect for multimedia fingerprinting. We propose new collusion-secure fingerprinting codes based on finite geometries (FGs) which increase the rate of conventional collusion-secure codes, while they guarantee to identify the same number of colluders. Due to the new FG-based fingerprinting codes, the system can deal with a larger number of users to distribute a digital content.
International conference proceedings, English

Short concatenated fingerprinting codes for multimedia data
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Proc. of Forty-fifth Annual Allerton Conference on Communication, Control, and Computing, 1040-1045, Sep. 2007, Peer-reviwed
International conference proceedings, English

A generalization of the parallel error correcting codes by allowing some random errors
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E90A, 9, 1745-1753, Sep. 2007, Peer-reviwed, This paper generalizes parallel error correcting codes proposed by Ahlswede et al. over a new type of multiple access channel called parallel error channel. The generalized parallel error correcting codes can handle with more errors compared with the original ones. We show construction methods of independent and non-independent parallel error correcting codes and decoding methods. We derive some bounds about the size of respective parallel error correcting codes. The obtained results imply a single parallel error correcting code can be constructed by two or more kinds of error correcting codes with distinct error correcting capabilities.
Scientific journal, English

New traceability codes against a generalized collusion attack for digital fingerprinting
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Information Security Applications (Lecture Notes in Computer Science), SPRINGER-VERLAG BERLIN, 4298, 252-266, Mar. 2007, Peer-reviwed, In this paper, we discuss collusion-secure traceability codes for digital fingerprinting which is a technique for copyright protection of digital contents. We first state a generalization of conventional collusion attacks where illicit users of a digital content collude to create an illegal digital content. Then we propose a collusion- secure traceability code which can detect at least one colluder against it. We show the rate and properties of the proposed traceability code.
Scientific journal, English

A generalization of the parallel error correcting codes
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Proc. of 2006 IEEE Information Theory Workshop (ITW2006), IEEE, 229-+, Oct. 2006, Peer-reviwed, This paper generalizes parallel error correcting codes proposed by Alshwede et al. over a type of multiple access channels called a parallel channel. The generalized parallel error correcting codes can handle with more errors compared with the original ones. We show construction methods of independent and non-independent parallel error correcting code and decoding methods. We derive some bounds about the size of respective parallel error correcting code.
International conference proceedings, English

Peformance of low-density parity-check codes for burst erasures
Gou Hosoya; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Proc. of 2006 Int. Symposium on Information Theory and its Applications (ISITA2006), 491-496, Oct. 2006, Peer-reviwed
International conference proceedings, English

Fast algorithm for generating candidate codewords in reliability-based maximum likelihood decoding
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E89A, 10, 2676-2683, Oct. 2006, Peer-reviwed, We consider the reliability-based heuristic search methods for maximum likelihood decoding, which generate test error patterns (or, equivalently, candidate codewords) according to their heuristic values. Some studies have proposed methods for reducing the space complexity of these algorithms, which is crucially large for long block codes at medium to low signal to noise ratios of the channel. In this paper, we propose a new method for reducing the time complexity of generating candidate codewords by storing some already generated candidate codewords. Simulation results show that the increase of memory size is small.
Scientific journal, English

A modification method for constructing low-density parity-check codes for burst erasures
Gou Hosoya; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E89A, 10, 2501-2509, Oct. 2006, Peer-reviwed, We study a modification method for constructing low-density parity-check (LDPC) codes for solid burst erasures. Our proposed modification method is based on a column permutation technique for a parity-check matrix of the original LDPC codes. It can change the burst erasure correction capabilities without degradation in the performance over random erasure channels. We show by simulation results that the performance of codes permuted by our method are better than that of the original codes, especially with two or more solid burst erasures.
Scientific journal, English

A heuristic search method with the reduced list of test error patterns for maximum likelihood decoding
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E88A, 10, 2721-2733, Oct. 2005, Peer-reviwed, The reliability-based heuristic search methods for maximum likelihood decoding (MLD) generate test error patterns (or, equivalently, candidate codewords) according to their heuristic values. Test error patterns are stored in lists and its space complexity is crucially large for MLD of long block codes. Based on the decoding algorithms both of Battail and Fang and of its generalized version suggested by Valembois and Fossorier, we propose a new method for reducing the space complexity of the heuristic search methods for MLD including the well-known decoding algorithm of Han et al. If the heuristic function satisfies a certain condition, the proposed method guarantees to reduce the space complexity of both the Battail-Fang and Han et al. decoding algorithms. Simulation results show the high efficiency of the proposed method.
Scientific journal, English

Efficient reliability-based soft decision decoding algorithm over Markov modulated channel
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Proc. of 2004 Int. Symposium on Information Theory and its Applications (ISITA2004), 823-826, Oct. 2004, Peer-reviwed
International conference proceedings, English

Modification methods for construction and performance analysis of low-density parity check-check codes over Markov-modulated channels
Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Proc. of 2004 Int. Symposium on Information Theory and its Applications (ISITA2004), 206-211, Oct. 2004, Peer-reviwed
International conference proceedings, English

An improved method of reliability-based maximum likelihood decoding algorithms using an order relation among binary vectors
Hideki Yagi; Manabu Kobayashi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E87A, 10, 2493-2502, Oct. 2004, Peer-reviwed, Reliability-based maximum likelihood decoding (MLD) algorithms of linear block codes have been widely studied. These algorithms efficiently search the most likely codeword using the generator matrix whose most reliable and linearly independent k (dimension of the code) columns form the identity matrix. In this paper, conditions for omitting unnecessary metrics computation of candidate codewords are derived in reliability-based MLD algorithms. The proposed conditions utilize an order relation of binary vectors. A simple method for testing if the proposed conditions are satisfied is devised. The method for testing proposed conditions requires no real number operations and, consequently, the MLD algorithm employing this method reduces the number of real number operations, compared to known reliability-based MLD algorithms.
Scientific journal, English

Complexity reduction of the Gazelle and Snyders decoding algorithm for maximum likelihood decoding
Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Lead, IEICE Trans. Fundamentals, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E86A, 10, 2461-2472, Oct. 2003, Peer-reviwed, Several reliability based code search algorithms for maximum likelihood decoding have been proposed. These algorithms search the most. likely codeword, using the most reliable information set. where the leftmost k (the dimension of code) columns of generator matrix are the most reliable and linearly independent. Especially, D. Gazelle and J. Snyders have proposed an efficient decoding algorithm and this algorithm requires small number of candidate codewords to find out the most likely codeword. In this paper, we propose new efficient methods for both generating candidate codewords and computing metrics of candidate codewords to obtain the most likely codeword at the decoder. The candidate codewords constructed by the proposed method are identical those in the decoding algorithm of Gazelle et al. Consequently, the proposed decoding algorithm reduces the time complexity in total; compared to the decoding algorithm of Gazelle et al. without the degradation in error performance.
Scientific journal, English

A note on conditions on random number generations with f-divergence
Ryo Nomura; Hideki Yagi
Last, Dec. 2024, Proc. of 47th Symposium on Information Theory and its Applications (SITA2024), Japanese, Summary national conference

Upper bounds on error probability for linear codes with mismatched decoding using decision feedback scheme
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
Dec. 2024, Proc. of 47th Symposium on Information Theory and its Applications (SITA2024), Summary national conference

Fast Polarization for Joint Source-Channel Coding with Side Information at Decoder
Yuki Nagai; Hideki Yagi
Last, Dec. 2024, Proc. of 47th Symposium on Information Theory and its Applications (SITA2024), Japanese, Summary national conference

Channel polarization for asymmetric q-Ary channels with q=2^r
Mikihisa Saito; Hideki Yagi
Last, Nov. 2023, Proc. of 46th Symposium on Information Theory and its Applications (SITA2023), Japanese

A problem of common randomness with capacity constraints over slow fading channel using two outage probabilities
Haruki Tomikawa; Hideki Yagi
Last, Nov. 2023, Proc. of 46th Symposium on Information Theory and its Applications (SITA2023), Japanese

Strong secrecy of biometric identification systems with passive eavesdropper
Shogo Koyanagi; Vamoua Yachongka; Hideki Yagi
Last, Nov. 2023, Proc. of 46th Symposium on Information Theory and its Applications (SITA2023), 105-110, Japanese

Multi-class classification based on error correcting output codes
Manabu Kobayashi; Gendo Kumoi; Hideki Yagi; Shigeichi Hirasawa
Nov. 2023, Proc. of 46th Symposium on Information Theory and its Applications (SITA2023), 83-88, Japanese

Source coding With unreliable side information under average error criterion
Kenji Aratani; Hideki Yagi
Last, Aug. 2023, IEICE Tech. Rep., IT2023-16, 123, 149, 13-16, Japanese

Polarization analysis for joint source-channel coding with side information
Yuki Nagai; Hideki Yagi
Last, Aug. 2023, IEICE Tech. Rep., IT2023-15, 123, 149, 7-12, Japanese

An improved context tree switching method by dynamic expansion and pruning of context tree
Masaya Ootsu; Hideki Yagi
Last, Jan. 2023, IEICE Tech. Rep., IT2022-36, 122, 355, 42-47, Japanese

A problem of common randomness over slow fading channel using outage probabilities
Haruki Tomikawa; Hideki Yagi
Last, Nov. 2022, Proc. of 45th Symposium on Information Theory and its Applications (SITA2022), 350-355, Japanese

Biometric identification systems with enrollment noise and passive eavesdropper
Shogo Koyanagi; Vamoua Yachongka; Hideki Yagi
Last, Nov. 2022, Proc. of 45th Symposium on Information Theory and its Applications (SITA2022), 344-349, Japanese

Strong converse theorem for utility-privacy trade-offs
Naruki Shinohara; Hideki Yagi
Last, Nov. 2022, Proc. of 45th Symposium on Information Theory and its Applications (SITA2022), 338-343, Japanese

Extensible polarization-adjusted convolutional codes and its application to rateless codes
Vamoua Yachongka; Michitaka Kurosu; Mizuho Asahi; Hideki Yagi; Koji Ishibashi
May 2022, IEICE Tech. Rep., IT2022-3, 122, 25, 13-18, English

Hybrid-ARQ scheme using systematic polarization-adjusted couvolutional codes
Mizuho Asahi; Vamoua Yachongka; Hideki Yagi
Last, 03 Mar. 2022, IEICE Tech. Rep., IT2021-87, 121, 428, 25-30, Japanese

Construction for BICM polar codes with polarization weight
Michitaka Kurosu; Vamoua Yachongka; Hideki Yagi
Last, 03 Mar. 2022, IEICE Tech. Rep., IT2021-86, 121, 428, 19-24, Japanese

A construction method for ECOC with constructive coding
Shigeichi Hirasawa; Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Hiroshige Inazumi
Mar. 2022, Proc. of 2022 IPSJ General Conference, Japanese, Summary national conference

Multivalued classification performance based on estimation error of binary classifiers
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
Dec. 2021, Proc. of 44th Symposium on Information Theory and its Applications (SITA2021), Japanese

Analysis on optimal error exponents of binary classification for mixed sources
Hiroto Kuramata; Hideki Yagi
Last, Dec. 2021, Proc. of 44th Symposium on Information Theory and its Applications (SITA2021), Japanese

A unified expression of achievable region in privacy-constrained source coding
Naruki Shinohara; Hideki Yagi
Last, Dec. 2021, Proc. of 44th Symposium on Information Theory and its Applications (SITA2021), English

Intrinsic randomness rate with respect to subclass of f-divergences using the smooth min entropy
Ryo Nomura; Hideki Yagi
24 Nov. 2021, IEICE Tech. Rep., IT2020-37, 120, 268, 73-78, Japanese

A construction method for ECOC with constructive coding
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
May 2021, 日本経営工学会春季大会予稿集, Japanese

Analysis of optimal error exponents for classification for Markov sources
Hiroto Kuramata; Hideki Yagi; Tsutomu Kawabata
05 Mar. 2021, IEICE Tech. Rep., IT2020-152, 120, 105, 245-250, Japanese

Local recovery with error tolerance for locally recoverable codes
Genki Oiwa; Hideki Yagi
Last, 03 Dec. 2020, IEICE Tech. Rep., IT2020-47, 120, 105, 129-133, Japanese

A study on the optimization of the ECOC method for multi-label classification problems
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
Dec. 2020, Proc. IPSJ MPS Tech. Rep., Japanese

A selection method of transmitted bits for Polar Codes using generalized Hamming weights
Mizuho Asahi; Vamoua Yachongka; Hideki Yagi
Last, 16 Jul. 2020, IEICE Tech. Rep., IT2020-11, 120, 105, 1-6, Japanese

A new characterization of the capacity region of biometric identification system under noisy enrollment
Vamoua Yachongka; Hideki Yagi
Last, 29 Nov. 2019, Proc. of 42nd Symposium on Information Theory and its Applications (SITA2019), 558, 563, English

Sum-capacity region of an SRAM-PUF multi-enrollment rate-constrained system
Lingyun Chen; Vamoua Yachongka; Hideki Yagi
Last, 29 Nov. 2019, Proc. of 42nd Symposium on Information Theory and its Applications (SITA2019), 564-569, English

A single-letter characterization for the minimum cost of information erasure under restriction on the output distribution
Naruaki Amada; Hideki Yagi
Last, 29 Nov. 2019, Proc. of 42nd Symposium on Information Theory and its Applications (SITA2019), 633-637, English

The Shannon cipher system over noisy channel with causal disclosure
Qipeng Wu; Hideki Yagi
Last, 29 Nov. 2019, Proc. of 42nd Symposium on Information Theory and its Applications (SITA2019), 638-643, English

Optimum source resolvability rate with respect to f-divergence and smooth Renyi entropy
Ryo Nomura; Hideki Yagi
17 Oct. 2019, Proc. 2019 Shannon Theory Workshop (STW2019), 10-16, English

A multi-value classification method using q-ary Exhaustive Code
Gendo Kumoi; Hideki Yagi; Manabu Kobayashi; Masayuki Goto; Shigeichi Hirasawa
IEICE and IPSJ, 03 Sep. 2019, Proc. 2019 Forum on Information Technology (FIT2019), 10-13, English

An improved bound on the dimension of (r, \delta)-locally repairable codes
Tomoya Hamada; Hideki Yagi
Last, 11 Dec. 2018, Proc. of 41st Symposium on Information Theory and its Applications (SITA2018), 76-81, Japanese

Fundamental trade-off among identification, secrecy, template, and privacy-leakage rates in biometric identification system
Vamoua Yachongka; Hideki Yagi
Last, 11 Dec. 2018, Proc. of 41st Symposium on Information Theory and its Applications (SITA2018), 505-510, English

Error exponent analysis for biometric identification systems with nonlegitimate entities
Hideki Yagi; Shigeichi Hirasawa
Lead, 11 Dec. 2018, Proc. of 41st Symposium on Information Theory and its Applications (SITA2018), 511-516, English

Polar codes achieving strong secrecy for broadcast channel with two confidential messages
Takahiro Fujita; Hideki Yagi
Last, Dec. 2018, Proc. of 41st Symposium on Information Theory and its Applications (SITA2018), 499-504, Japanese

An improved bound on dimension of locally repairable codes
Tomoya Hamada; Hideki Yagi
Last, 05 Sep. 2018, IEICE Tech. Rep., IT2018-27, 118, 205, 1-6, Japanese

On the minimum cost of information erasure for stationary memoryless sources
Naruaki Amada; Hideki Yagi
Last, 19 Jul. 2018, IEICE Tech. Rep., IT2018-17, 118, 139, 25-29, Japanese

Lattice codes for strong interference channel via rate-splitting approach
Yuki Yoshioka; Hideki Yagi
Last, 23 Jan. 2018, IEICE Tech. Rep., IT2017-90, 117, 394, 207-212, Japanese

A simple proof of polarization for stationary memoryless sources and its extension to non-stationary memoryless sources
Yuming Yang; Hideki Yagi
Last, 23 Jan. 2018, IEICE Tech. Rep., IT2017-91, 117, 394, 213-218, Japanese

Bidirectional broadcast channel under strong secrecy and cost constraints
Akinori Inaba; Hideki Yagi
Last, 23 Jan. 2018, IEICE Tech. Rep., IT2017-92, 117, 394, 219-224, Japanese

The capacity region of identification, secrecy and compression rates in biometric identification systems
Vamoua Yachongka; Hideki Yagi
Last, 22 Jan. 2018, IEICE Tech. Rep., IT2017-60, 117, 394, 31-36, English

Variable-length channel resolvability for discrete memoryless sources and channels
Hideki Yagi; Te Sun Han
Lead, 30 Nov. 2017, Proc. of 40th Symposium on Information Theory and its Applications (SITA2017), 259-264, English

A study on codeword table construction in multilevel classification based on error correcting code using artificial data
Gendo Kumoi; Kenta Mikawa; Hideki Yagi; Masayuki Goto; Shigeichi Hirasawa
29 Nov. 2017, Proc. of 40th Symposium on Information Theory and its Applications (SITA2017), 259-264, Japanese

Variable-length channel resolvability for mixed sources and non-mixed channels
Hideki Yagi; Te Sun Han
Lead, 20 Oct. 2017, Proc. 2017 Shannon Theory Workshop (STW2017), 9-16, English

Biometric identification system with protected templates under noisy enrollment
Vamoua Yachongka; Hideki Yagi
Last, 12 Sep. 2017, Proc. of 2017 IEICE Society Conference, 19-19, English

First- and second-order optimistic coding theorems on variable-length codes allowing non-vanishing error probability
Ryo Nomura; Hideki Yagi
電子情報通信学会, 08 Sep. 2017, IEICE Tech. Rep., IT2017-42, 117, 208, 21-26, English, 0913-5685, 40021342296, AN10013083

A codeword construction method for multilevel document classification using correlation of binary discriminators from the viewpoint of coding theory
Gendo Kumoi; Hideki Yagi; Masayuki Goto; Shigeichi Hirasawa
Sep. 2017, IPSJ MPS Tech. Rep., 0, Japanese

Construction of coding table method focused on correlation of binary discriminator in multilevel document classification based on coding theory
Gendo Kumoi; Hideki Yagi; Masayuki Goto; Shigeichi Hirasawa
Sep. 2017, Proc. of 2017 Forum on Information Technology (FIT2017), 0, Japanese

Polar codes achieving strong secrecy for broadcast channel with confidential messages
Takahiro Fujita; Hideki Yagi
Last, 13 Jul. 2017, IEICE Tech. Rep., IT2017-28, 117, 120, 67-72, Japanese

Exponential error bounds for block codes constructed by unit memory trellis codes
Shigeichi Hirasawa; Hideki Yagi; Manabu Kobayashi; Masao Kasahara
電子情報通信学会, 13 Jul. 2017, IEICE Tech. Rep., IT2017-33, 117, 120, 97-102, English, 0913-5685, 40021285165, AN10013083

Construction of locally repairable codes with multiple localities based on encoding polynomial
Tomoya Hamada; Hideki Yagi
Last, Jul. 2017, IEICE Tech. Rep., IT2017-21, 117, 120, 27-32, Japanese

Overflow probability of variable-length codes allowing non-vanishing error probability
Ryo Nomura; Hideki Yagi
電子情報通信学会, 09 Mar. 2017, IEICE Tech. Rep., IT2016-126, 116, 505, 173-178, English, 0913-5685, 40021159153, AN10060811

On block codes constructed by tail biting unit memory trellis codes
Shigeichi Hirasawa; Hideki Yagi; Manabu Kobayashi; Masao Kasahara
Mar. 2017, Proc. 2017 IEICE General Conference, English

A study on construction of ECOC matrix for multi-valued document classification based on performance of binary classifiers
Gendo Kumoi; Hideki Yagi; Masayuki Goto; Shigeichi Hirasawa
Mar. 2017, Proc. 2017 IPSJ General Conference, 0, Japanese

Variable-length lossy compression allowing positive overflow and excess distortion probabilities
Shota Saito; Hideki Yagi; Toshiyasu Matsushima
14 Dec. 2016, Proc. of 39th Symposium on Information Theory and its Applications (SITA2016), 164-169, English

Optimistic channel resolvability and the strong converse property
Hideki Yagi
Lead, 14 Dec. 2016, Proc. of 39th Symposium on Information Theory and its Applications (SITA2016), 47-52, English

Channel resolvability over single and compound channels
Hideki Yagi
Lead, 電子情報通信学会, 02 Sep. 2016, IEICE Tech. Rep., IT2016-41, 116, 206, 41-46, English, 0913-5685, 40020961522, AN10013083

Lattice codes for Gaussian broadcast channel with common message
Yuki Yoshioka; Hideki Yagi
Last, 21 Jul. 2016, IEICE Tech. Rep., IT2016-23, 116, 163, 13-18, Japanese

Polar coding for bidirectional broadcast channel with non-binary output alphabets
Akinori Inaba; Hideki Yagi
Last, 電子情報通信学会, 21 Jul. 2016, IEICE Tech. Rep., IT2016-24, 116, 163, 19-24, English, 0913-5685, 40020907893, AN10013083

Refined analysis of optimum coding rate for channels with states
Hideki Yagi
Lead, 電子情報通信学会, 11 Mar. 2016, IEICE Tech. Rep., WBS2015-120, 115, 500, 221-228, Japanese, Invited, Summary national conference

Shulman-Feder bound for Forney's generalized decoding using q-ary linear codes
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
Nov. 2015, Proc. of 38th Symposium on Information Theory and its Applications (SITA2015), Japanese

Variable-length coding with cost allowing non-vanishing error probability
Hideki Yagi; Ryo Nomura
Lead, Nov. 2015, Proc. of 38th Symposium on Information Theory and its Applications (SITA2015), English

Analysis on reliability function and strong converse of discrete memoryless biometrical identification systems
Yachongka Vamoua; Hideki Yagi
Last, 電子情報通信学会, 21 May 2015, IEICE Tech. Rep., IT2015-3, 13, 37, 13-18, English, 0913-5685, 40020491539

The capacity region of general multiple access channel with partially cooperating encoders
Ayato Murakoshi; Hideki Yagi
Last, 02 Dec. 2014, Proc. of 37th Symp. on Information Theory and its Applications (SITA2014), 565-570, Japanese

Optimistic coding with an epsilon-fidelity criterion and strong converse theorem
Hideki Yagi; Ryo Nomura
Lead, Dec. 2014, Proc. of 37th Symposium on Information Theory and its Applications (SITA2014), Japanese

Source coding theorem with a fidelity criterion allowing some probability of union of overflow and excess distortion
Ryo Nomura; Hideki Yagi
Dec. 2014, Proc. of 37th Symposium on Information Theory and its Applications (SITA2014), Japanese

Applying write once memory codes to asymmetric multiple access channel with errors
Ryota Sekiya; Erick C. G. Alvarez; Brian Kurkoski; Hideki Yagi
Dec. 2014, Proc. of 37th Symposium on Information Theory and its Applications (SITA2014), English

Finite-length analysis in channel coding
Hideki Yagi
Lead, IEICE, 23 Sep. 2014, Proc. 2014 IEICE Society Conference, AT-2-2, Japanese, Invited

On relations between DS2 bound and Sulman-Feder bound for Forney's Generalized Decoding
Toshihiro Niinomi; Hideki Yagi; Shigeichi Hirasawa
For maximum likelihood decoding, Shamai and Sason have pointed out that various upper bounds which were known are a special case of the DS2 bound. Then, recently, Hof et al. extended this discussion to generalized decoding (GD), which was introduced by Forney with decision criterion FR. Hof et al. also derived the Sulman-Feder bound for GD (GD-SF) for the binary-input output-symmetric channel under some proper conditions. However, this bound employs one parameter, though Forney's original upper bound has two parameters. In this paper, by choosing a proper function g(y), we derive a new GD-SF using two parameters and clarify this bound is tighter than Hof et al.'s GD-SF., The Institute of Electronics, Information and Communication Engineers, 19 Sep. 2014, IEICE Tech. Rep., IT2014-43, 114, 224, 13-18, Japanese, 0913-5685, 110009950856, AN10013083

A sweeping trend in theory of channel coding -finite blocklength analysis-
Hideki Yagi
Lead, There has been a recent trend of studies which analyze the fundamental limit of achievable coding rates under a fixed code length in Shannon theory, and the research topic in this trend is referred to as "finite block-length analysis". Papers authored by Hayashi and Polyanskiy, Poor, and Verdu have won 2011 IEEE IT Society paper Award, boosting this topic in channel coding. This paper explains basic concepts and recent results of finite blocklength analysis especially from the approach of Polyanskiy et al., which makes full use of relationships between channel coding and hypothesis testing., 電子情報通信学会, 26 Nov. 2013, IEICE Tech. Rep., IT2013-43, 113, 319, 19-26, Japanese, Invited, Summary national conference, 0913-5685, 110009888058, AN10013083

Error expoenent of universal fingerprinting code for memoryless and fair collusion attacks
Tomoya Narita; Hideki Yagi
Last, 19 Nov. 2013, Proc. of 36th Symp. on Information Theory and its Applications (SITA2013), 580-585, Japanese

Two-bit LDPC LUT decoder based on maximization of mutual information
Francisco J; C. Romero; Brian M. Kurkoski; Hideki Yagi
19 Nov. 2013, Proc. of 36th Symp. on Information Theory and its Applications (SITA2013), 232-237, English

Channel dispersion for a class of mixed channels decomposed into stationary memoryless channels
Hideki Yagi; Ryo Nomura
Lead, Nov. 2013, Proc. of 36th Symposium on Information Theory and its Applications (SITA2013), Japanese

Finite blocklength analysis for multiple access channels and composite hypothesis testing
Hideki Yagi; Yasutada Oohama
Lead, Dec. 2012, Proc. of 35th Symposium on Information Theory and its Applications (SITA2012), Japanese

Analysis on the fingerprinting capacity for the memoryless and fair collusion Attacks
Tomoya Narita; Hideki Yagi; Tsutomu Kawabata
Dec. 2012, Proc. of 35th Symposium on Information Theory and its Applications (SITA2012), Japanese

The capacity of fingerprinting codes against several attack classes with unknown size of colluders
Gou Hosoya; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Nov. 2011, Proc. of 34th Symposium on Information Theory and its Applications (SITA2011), English

An approach to designing channel quantizers using the random coding exponent
Hideki Yagi; Brian Kurkoski
Lead, Nov. 2011, Proc. of 34th Symposium on Information Theory and its Applications (SITA2011), English

Replica shuffled BP decoding algorithms for irregular LDPC codes based on degree distributions
Yoshiyuki Sato; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Oct. 2008, Proc. of 31st Symposium on Information Theory and its Applications (SITA2008), 129-134, Japanese

A locally modified image detection method using Euler vector
Takehiro Fujita; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Oct. 2008, Proc. of 31st Symposium on Information Theory and its Applications (SITA2008), 837-842, Japanese

On designing irregular LDPC codes using accurate densities for Gilbert-Elliott channel
Manabu Kobayashi; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Oct. 2008, Proc. 31th Symposium on Information Theory and its Applications (SITA2008), 516-521, English

Near duplicated image detection by learning with difference vector to original image
Toshiyuki Sano; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Feb. 2008, IEICE Tech. Rep., ITS2007-62, 107, 487, 1-6, Japanese

Image retrieval using bit-plane for JPEG2000 coded texture image
Tatsuya Noguchi; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Dec. 2007, IEICE Tech. Rep., IE2007-119, 107, 380, 39-43, Japanese

A heuristic search method of symbol node grouping for ahuffled BP decoding algorithm
Yoshiyuki Sato; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Nov. 2007, Proc. of 30th Symposium on Information Theory and its Applications (SITA2007), 18-23, Japanese

Error control codes for parallel channel with correlated errors
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Oct. 2007, Proc. of 30th Symposium on Information Theory and its Applications (SITA2007), 867-872, English

A symbol grouping method of shuffled BP algorithm for LDPC codes
Yoshiyuki Sato; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
May 2007, IEICE Tech. Rep., IT2007-3, 107, 42, 13-18, Japanese

Shortened and concatenated collusion-secure codes for digital fingerprinting
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, May 2007, IEICE Tech. Rep. IT2007-6, 107, 42, 31-36, English

Shortening methods of collusion-secure codes for digital fingerprinting
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
May 2007, Proc. of 2007 Hawaii and SITA Joint Conference on Information Theory (HISC2007), 73-78, English

An adaptive decoding algorithm of LDPC codes over the binary erasure channel
Gou Hosoya; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
May 2007, Proc. of 2007 Hawaii and SITA Joint Conference on Information Theory (HISC2007), 154-159, English, Peer-reviwed

Text Categorization Using Naive Bayes Model Based on Co-Occurrence words
Yuichi Tsuda; Hideki Yagi; Shigeichi Hirasawa
28 Nov. 2006, 情報理論とその応用シンポジウム予稿集 = The proceedings of the Symposium on Information Theory and Its Applications, 29, 2, 613-616, Japanese, 10022582224, AA11796188

Document clustering methods based on probabilistic latent semantic indexing with feature of words
Masafumi Nagao; Hideki Yagi; Shigeichi Hirasawa
28 Nov. 2006, Proc. of 29th Symposium on Information Theory and its Applications (STIA2006), 29, 2, 617-620, Japanese, 10022582232, AA11796188

Improved bit-flipping decoding algorithms of lowdensity parity-check codes with updating reliabilities
Yu Hasegawa; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Nov. 2006, Proc. of 29th Symposium on Information Theory and its Applications (SITA2006), 649-652, Japanese

Performance analysis of EM decoding algorithm for HMM channels
Manabu Kobayashi; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Nov. 2006, Proc. of 29th Symposium on Information Theory and its Applications (SITA2006), 291-294, Japanese

On correctable burst-erasure lengths for LDPC codes with column permuted parity-check matrices
Gou Hosoya; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Nov. 2006, Proc. 29th Symposium on Information Theory and its Applications (SITA2006), 645-648, English

Decoding performance of linear parallel error correcting codes
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Nov. 2006, Proc. of 29th Symposium on Information Theory and its Applications (SITA2006), 189-192, English

A new class of traceability codes for digital fingerprinting
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, May 2006, Proc. of 2006 Hawaii, IEICE and SITA Joint Conference on Information Theory (HISC2006), 13-18, English

A modification method for constructing low-density parity-check codes for burst erasures
Gou Hosoya; Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Mar. 2006, IEICE Tech. Rep., IT2005-121, 153-158, English

A method of a detection of double-use of the ticket for e-ticket system of refreshable tokens
Koji Enoki; Hideki Yagi; Katsuyuki Umezawa; Shigeichi Hirasawa
Nov. 2005, Proc. of 28th Symposium on Information Theory and its Applications (SITA2005), 579-582, Japanese

Weighted bit-flipping decoding algorithms of low-density parity-check codes with updating reliabilities
Tadashi Sato; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Nov. 2005, Proc. of 28th Symposium on Information Theory and its Applications (SITA2005), 9-12, Japanese

Collusion-secure codes for fingerprinting based on finite geometries
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Nov. 2005, Proc. of 28th Symposium on Information Theory and its Applications (SITA2005), 701-704, Japanese

A decoding algorithm for q-ary turbo codes by deleting trellis branches
Yu Hasegawa; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Jul. 2005, IEICE Tech. Rep. IT2005-37, 9-14, Japanese

Fast algorithm for generating candidate codewords in reliability-based maximum likelihood decoding
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, May 2005, Proc. of 2005 Hawaii, IEICE and SITA Joint Conference on Information Theory (HISC2005), 73-78, English

A relevance feedback method using several query vectors
Yuya Hayashita; Hideki Yagi; Shigeichi Hirasawa
14 Dec. 2004, Proc. of 27th Symposium on Information Theory and its Applications (SITA2004), 27, 1, 49-52, Japanese, 10014280161, AA11796188

An improved soft-decision decoding algorithm based on sort-and-match technique
Satoshi Nieda; Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
14 Dec. 2004, Proc. of 27th Symposium on Information Theory and its Applications (SITA2004), 27, 2, 567-570, Japanese, 10014281191, AA11796188

Complexity reduction method of suboptimal maximum likelihood decoding algorithms for tail-biting convolutional codes
Tadashi Sato; Hideki Yagi; Shigeichi Hirasawa
Jul. 2004, IEICE Tech. Rep., IT2004-25, 41-46, Japanese

Analysis of decoding performance of low-density parity-check codes for channels with memory
Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Dec. 2003, Proc. of 26th Symposium on Information Theory and its Applications (SITA2003), 269-272, Japanese

An efficient block turbo decoding algorithm over channels with memory
Shinji Wakasa; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Dec. 2003, Proc. of 26th Symposium on Information Theory and its Applications (SITA2003), 85-88, Japanese

A method for reducing space complexity of reliability based heuristic search maximum likelihood decoding algorithms
Hideki Yagi; Toshiyasu Matsushima; Shigeichi Hirasawa
Lead, Dec. 2003, Proc. of 26th Symposium on Information Theory and Its Applications (SITA2003), 185-188, English

Turbo decoding algorithms for burst error channels -efficient decoding algorithms of block turbo codes-
Shinji Wakasa; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Jul. 2003, IEICE Tech. Rep. IT2003-21, 61-66, Japanese

Construction methods of low-density parity-check codes for burst error channels
Gou Hosoya; Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Jul. 2003, IEICE Tech. Rep., IT2003-20, 61-66, Japanese

An improved method of maximum likelihood decoding algorithms using the most reliable basis based on an order relation among binary vectors
Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Lead, May 2003, IEICE Tech. Rep. IT2003-6, 23-28, English

An efficient reliability-based soft desicion decoding algorithm over hidden Markov noise channel
Hideki Yagi; Manabu Kobayashi; Shigeichi Hirasawa
Lead, Dec. 2002, Proc. of 25th Symposium on Information Theory and its Applications (SITA2002), pp.11-14, Japanese

A decoding algorithm of low density parity check codes for hidden Markov noise channel
Gou Hosoya; Hideki Yagi; Shigeichi Hirasawa
Jul. 2002, IEICE Tech. Rep., IT2002-23, 19-24

On sectionalization of trellis for block codes
Hideki Yagi; Tomotsugu Okada; Manabu Kobayashi; Shigeichi Hirasawa
Lead, Mar. 2000, IEICE Tech. Rep., IT99-97, 69-74, Japanese

非一様な入力に対する多重アクセス通信路の分極現象
坂英斗; 八木秀樹
第47回情報理論とその応用シンポジウム（ポスター発表）
Dec. 2024

動く教材で学ぶデータエンジニアリング
雲居玄道; 八木秀樹; 後藤正幸
Japanese, 日本経営工学会春季大会
15 May 2021

A unified approach to designing channel quantizers for binary-input memoryless channels
Hideki Yagi; Brian Kurkoski
Others, Japanese, 2011LDPC符号ワークショップ, LDPC符号ワークショップ
Sep. 2011

Generalized time-sharing for asynchronous interference channels
Hideki Yagi; H. Vincent Poor
Others, English, 2011 Inform. Theory and Applications Workshop, Univ. of California, San Diego
Feb. 2011

Improved rate-equivocation regions for secure cooperative communication
Ninoslav Marina; Hideki Yagi; H. Vincent Poor
Others, English, 2011 Inform. Theory and Applications Workshop, Univ. of California, San Diego
Feb. 2011

Optimal non-uniform quantization of LDPC decoders
Brian Kurkoski; Hideki Yagi
Others, English, 2010 Information Theory and Applications Workshop, Univ. of California, San Diego
Feb. 2010

Error exponents for linear codes under maximum likelihood decoding at low rates
Hideki Yagi; H. Vincent Poor
Others, English, 2010 Information Theory and Applications Workshop, Univ. of California, San Diego
Feb. 2010

Soc. of Information Theory and its Applications (SITA)

Research Institute of Signal Processing, Japan

IEICE

IEEE

Studies on Automatic Repeat-Request and List Decoding for Mismatched Decoing
Toshihiro Niinomi
Coinvestigator
2023 - 2026

Advanced Theory for Highly Reliable and Secure Coding Systems
Hidek Yagi
Principal investigator
2020 - 2024

第5世代移動通信システムの更なる高度化に向けた研究開発
石橋功至
総務省, 研究助成, Coinvestigator
Aug. 2019 - Mar. 2023

IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
Yasutada Oohama
Coinvestigator
2018 - 2023

Analysis of Information Transformation for Highly Reliable and Secure Communication and Recording Systems
Hideki Yagi
Principal investigator
2016 - 2020

線形符号・LDPC符号を用いた判定帰還方式における誤り指数と計算量の削減について
Toshihiro Niinomi
Coinvestigator
2017 - 2019

LatticeNET: Practical Lattice Codes for Cooperative Wireless Networks
Brian Kurkoski
Coinvestigator
2014 - 2017

Refinement of Multi-User Information Theory for Highly Reliable Network
Hideki Yagi
Principal investigator
2013 - 2015

Development of Fundamental Theory on Multi-User Channel Coding for High Speed Network
Hideki Yagi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Young Scientists (B), Principal investigator, This study aims to analyze coding rates of optimal codes and to develop methods for constructing codes that can approach the theoretical limit over multi-user communication systems. The main result is to develop an explicit construction method of codes having the following three properties over a (compound) multiple access channel: (1) they can be implemented with the complexity polynomial in the code length N, (2) they can approach the optimal coding rates asymptotically, and (3) their decoding error probability can converge to zero exponentially in N. Another important result is to give bounds on coding rates of optimal codes with a fixed code length N, which are tighter than known bounds., 22760270
2010 - 2012

マルチメディアコンテンツの著作権保護を目的とした高効率なデジタル指紋符号の開発
Hideki Yagi
Principal investigator
2008 - 2009

デジタルコンテンツの著作権保護のための符号化手法に関する研究
電気通信普及財団, Principal investigator
2007 - 2009

ＷＥＢコンテンツの著作権侵害検出サーチエンジンに関する研究
平澤茂一
電気通信普及財団, Coinvestigator
2006 - 2008

早大と電通大、2値分類器の結合による多値分類法の理論的解析に成功
日本経済新聞社, 日本経済新聞プレスリリース, https://www.nikkei.com/article/DGXZRSP648652_S3A200C2000000/, Paper
Mar. 2023

第48回情報理論とその応用シンポジウム(SITA2025)
Competition etc, Planning etc, Nov. 2025 - Nov. 2025