Papers - Koichi BETSUMIYA
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Automorphism groups of cyclic orbifold vertex operator algebras associated with the Leech lattice and some non-prime isometries
Koichi Betsumiya, Ching Hung Lam, Hiroki Shimakura
Israel Journal of Mathematics 2023.10
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Automorphism groups and uniqueness of holomorphic vertex operator algebras of central charge $24$
Koichi Betsumiya, Ching Hung Lam, Hiroki Shimakura
Communications in Mathematical Physics 399 ( 3 ) 1773 - 1810 2022.12
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tame 自己同型群について
別宮 耕一
第31回有限群論草津セミナー報告集 31 1 - 3 2020.3
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拡張ハミング符号と正六百胞体との対応について
別宮 耕一
第30回有限群論草津セミナー報告集 30 37 - 42 2019.3
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Triply even code の極大性判定
別宮 耕一
第29回有限群論草津セミナー報告集 - 14 - 17 2018.3
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立方重偶符号の自己同型群に現れる単純群
別宮耕一
第２７回有限群論草津セミナー報告集 29 - 32 2016.3
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組合せ構造における純粋ナッシュ均衡性
別宮耕一
第２６回有限群論草津セミナー報告集 6 - 8 2015.7
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On triply even codes
BETSUMIYA Koichi
RIMS Kokyuroku 1844 139 - 145 2013.7
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Upper bounds on cyclotomic numbers
Koichi Betsumiya, Mitsugu Hirasaka, Takao Komatsu, Akihiro Munemasa
Linear Algebra and Its Applications 438 ( 1 ) 111 - 120 2013.1
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Classification of doubly even self-dual codes of length 40
別宮 耕一
第29回代数的組合せ論シンポジウム報告集 10 - 16 2013
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A complete classification of doubly even self-dual codes of length 40
Betsumiya Koichi, Harada Masaaki, Munemasa Akihiro
ELECTRONIC JOURNAL OF COMBINATORICS 19 ( 3 ) 2012.8
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On triply even binary codes
Koichi Betsumiya, Akihiro Munemasa
JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES 86 ( 1 ) 1 - 16 2012.8
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Hadamard matrices of order 32 and extremal ternary self-dual codes
Koichi Betsumiya, Masaaki Harada, Hiroshi Kimura
Designs, Codes and Cryptography. An International Journal 58 ( 2 ) 203 - 214 2011.2
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Invariant ring of Clifford-Weil group, and Jacobi forms over totally real field.
BETSUMIYA Koichi, Choie, YoungJu
Séminaires et Congrès 21 1 - 16 2010
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Mass Formula for Even Codes over Z4 （共著）
Koichi Betsumiya, Rowena Alma L. Betty and Akihiro Munemasa
Springer-Verlag Lecture Notes in Computer Science 5921 15 - 17 2009.12
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Mass formula for even codes over Z_8
別宮 耕一, 宗政 昭弘
Cryptography and Coding, Springer LNCS 5921 65 - 77 2009
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Minimum Lee weights of type II codes over F2r
Koichi BETSUMIYA
Discrete Mathematics 308 ( 14 ) 3018 - 3022 2008.7
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Type II codes over Galois rings
別宮耕一
第２４回代数的組合せ論シンポジウム報告集 51 - 54 2007.11
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アダマール行列による超立方体の分割
別宮耕一
第１８回有限群論草津セミナー報告集 69 - 70 2006.12
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Special Self-Dual Codes over $\mathbb{F}_4$(Theory and Applications of Combinatorial Designs with Related Field)
Betsumiya Koichi
1465 119 - 125 2006.1
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Ozeki polynomials and Jacobi forms
K Betsumiya, Y Choie
ARS COMBINATORIA 77 233 - 244 2005.10
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Codes over F4, Jacobi forms and Hilbert-Siegel modular forms over Q(√5) （共著）
Koichi BETSUMIYA, YoungJu CHOIE
European Journal of Combinatorics 26 ( 5 ) 629 - 650 2005.7
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Jacobi forms over totally real fields and type II codes over Galois rings GR(2(m), f)
K Betsumiya, Y Choie
EUROPEAN JOURNAL OF COMBINATORICS 25 ( 4 ) 475 - 486 2004.5
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Optimal self-dual codes over F2×F2 with respect to the Hamming weight （共著）
Koichi BETSUMIYA, Masaaki HARADA
IEEE Transactions on Information Theory 50 ( 2 ) 356 - 358 2004.2
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Type II codes over F2m+uF2m （共著）
Koichi BETSUMIYA, San LING, Fidel R. NEMENZO
Discrete Mathematics 275 ( 1-3 ) 43 - 65 2004.1
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Formally self-dual codes related to Type II codes
K Betsumiya, M Harada
APPLICABLE ALGEBRA IN ENGINEERING COMMUNICATION AND COMPUTING 14 ( 2 ) 81 - 88 2003.8
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Extremal self-dual codes over F-2 x F-2
K Betsumiya, TA Gulliver, M Harada
DESIGNS CODES AND CRYPTOGRAPHY 28 ( 2 ) 171 - 186 2003.3
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On self-dual codes over some prime fields （共著）
Koichi Betsumiya, Stelios Georgiou, T. Aaron Gulliver, Masaaki, Harada, Christos Koukouvinos
Discrete Mathematics 262 ( 1-3 ) 37 - 58 2003.2
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On self-dual codes over some prime fields
K Betsumiya, S Georgiou, TA Gullivere, M Harada, C Koukouvinos
DISCRETE MATHEMATICS 262 ( 1-3 ) 37 - 58 2003.2
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Type II codes over F2r （共著）
Koichi BETSUMIYA, Masaaki HARADA, Akihiro MUNEMASA
Springer-Verlag Lecture Notes in Computer Science 227 102 - 111 2001.11
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On Type II codes over F4 （共著）
Koichi BETSUMIYA, T. Aaron GULLIVER, Masaaki HARADA, Akihiro MUNEMASA
IEEE Transactions on Information Theory 47 ( 6 ) 2242 - 2248 2001.9
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On type II codes over F-4
K Betsumiya, TA Gulliver, M Harada, A Munemasa
IEEE TRANSACTIONS ON INFORMATION THEORY 47 ( 6 ) 2242 - 2248 2001.9
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Classification of Type II code over GF(4) of some small lengths (Codes, lattices, vertex operator algebras and finite groups)
Betsumiya Koichi
1228 43 - 50 2001.9
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Classification of formally self-dual even codes of lengths up to 16 （共著）
Koichi BETSUMIYA, Masaaki HARADA
Designs, Codes and Cryptography 23 ( 3 ) 235 - 332 2001.8
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Binary optimal odd formally self-dual codes
K Betsumiya, M Harada
DESIGNS CODES AND CRYPTOGRAPHY 23 ( 1 ) 11 - 21 2001.5
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Binary optimal odd formally self-dual codes （共著）
Koichi BETSUMIYA, Masaaki HARADA
Designs, Codes and Cryptography 23 ( 1 ) 11 - 21 2001.3
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Classification of formally self-dual even codes of lengths up to 16
K Betsumiya, M Harada
DESIGNS CODES AND CRYPTOGRAPHY 23 ( 3 ) 325 - 332 2001
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Type II Codes over F2r.
Koichi Betsumiya, Masaaki Harada, Akihiro Munemasa
Applied Algebra, Algebraic Algorithms and Error-Correcting Codes, 14th International Symposium, AAECC-14, Melbourne, Australia November 26-30, 2001, Proceedings 102 - 111 2001
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On type II codes over F-4
K Betsumiya, TA Gulliver, M Harada, A Munemasa
2000 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY, PROCEEDINGS 47 ( 6 ) 141 - 141 2000
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Binary optimal linear rate 1/2 codes (共著)
Koichi BETSUMIYA, Masaaki HARADA
Springer-Verlag Lecture Notes in Computer Science 1719 462 - 471 1999.11
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On binary extremal formally self-dual even codes (共著)
Koichi BETSUMIYA, T. Aaron GULLIVER, Masaaki HARADA
Kyushu Journal of Mathematics 53 ( 2 ) 421 - 430 1999.9