1. Homogeneity theorems on perfect codes in Hamming schemes and generalized Hamming schemes, Tokyo J. Mathematics, 8 (1985), 429-438.
  2. An analogue of t-designs in association schemes of alternating bilinear forms, Graphs and Combinatorics, 2 (1986), 259-267.
  3. On nonsymmetric P- and Q-polynomial association schemes, J. Combinatorial Theory, Ser. B 51 (1991), 314-328.
  4. Splitting fields of association schemes, J. Combinatorial Theory, Ser. A 57 (1991), 157-161.
  5. On pseudo-automorphisms and fusions of an association scheme, Europ. J. Combinatorics, 12 (1991), 317-325 (with T. Ikuta and T. Ito).
  6. Amorphous association schemes over the Galois rings of characteristic 4, Europ. J. Combinatorics, 12 (1991), 513-526 (with T. Ito and M. Yamada).
  7. Paires orthogonales de sous-algebres involutives, C. R. Acad. Sci. Paris, Serie I, 314 (1992), 329-331 (with Y. Watatani).
  8. An inequality for primitive translation association schemes, Memoirs Fac. Sci., Kyushu Univ., Ser. A, 46 (1992), 189-194 (with T. Itoh).
  9. A local characterization of the graph of alternating forms, Finite Geometry and Combinatorics, F. De Clerck, et al., editors, 289-302, Cambridge University Press, 1993 (with S. V. Shpectorov).
  10. A local characterization of the graphs of alternating forms and the graphs of quadratic forms over GF(2), Finite Geometry and Combinatorics, F. De Clerck, et al., editors, 303-317, Cambridge University Press, 1993 (with D. V. Pasechnik and S. V. Shpectorov).
  11. The automorphism group and the convex subgraphs of the quadratic forms graph in characteristic 2, J. Algebraic Combin. 2 (1993), 411-419 (with D. V. Pasechnik and S. V. Shpectorov).
  12. Generalized spin models, J. Knot Theory and its Ramifications 3 (1994), 465-475 (with K. Kawagoe and Y. Watatani).
  13. The Terwilliger algebras of group association schemes, Kyushu J. Mathematics 49 (1995), 93-102 (with E. Bannai). preprint version (paper, appendix)
  14. On a class of small 2-designs over GF(q), J. Combinatorial Designs, 5 (1995) 61-77 (with M. Miyakawa and S.Yoshiara).
  15. On perfect t-shift codes in abelian groups, Designs, Codes and Cryptography 5 (1995), 253-259.
  16. An alternative construction of the graphs of quadratic forms in characteristic 2, Algebra Colloquium 2 (1995), 275-287.
  17. On fusion algebras associated to finite group actions, Pacific J. Math., 177 (1997), 269-290 (with H. Kosaki and S. Yamagami).
  18. Orthogonal arrays, primitive trinomials, and shift-register sequences, Finite Fields and Their Applications, 4 (1998), 252-260.
  19. Duality maps of finite abelian groups and their applications to spin models, J. Algebraic Combinatorics, 8 (1998), 223-233 (with Etsuko Bannai).
  20. New 5-designs with automorphism group PSL(2,23), J. Combinatorial Designs, 7 (1999), 147-155 (with M. Kitazume).
  21. Flag-transitive 2-designs arising from line-spreads in PG(2n-1,2), Geometriae Dedicata, 77 (1999), 209-213.
  22. Type IV Self-Dual Codes over Rings, IEEE Trans. Inform. Theory, 45 (1999), 2345-2360. (with S. T. Dougherty, P. Gaborit, M. Harada and P. Sole).
  23. Tight 2-designs and perfect 1-codes in Doob graphs, J. Stat. Planning and Inference, 86 (2000), 505-513 (with J. H. Koolen).
  24. Classification of Type IV Self-Dual Z_4-Codes of Length 16, Finite Fields and Their Applications 6 (2000), 244-254. (with M. Harada).
  25. On Type II codes over F_4, IEEE Transactions on Information Theory, 47 (2001), 2242-2248 (with K. Betsumiya, T. A. Gulliver and M. Harada)
  26. Some results on modular forms --- subgroups of the modular group whose ring of modular forms is a polynomial ring, ``Groups and Combinatorics --- in Memory of Michio Suzuki,'' 245-254, Advanced Studies in Pure Mathematics 32, Mathematical Society of Japan, 2001 (with E. Bannai, M. Koike and J. Sekiguchi).
  27. Type II codes over F_2^r, ``Applied Algebra, Algebraic Algorithms and Error Correcting Codes,'' 2001, Springer Lecture Notes in Comp. Sci. 2227, 102-111 (with Koichi Betsumiya and Masaaki Harada).
  28. A Correction to ``Incidence matrices and finite cyclic projective planes'' by Chat Yin Ho, Des. Codes Cryptogr., 25 (2002), 91--93. (with D. Brozovic and C. Ho).
  29. A mass formula for Type II codes over finite fields of characteristic two, ``Codes and Designs,'' Proceedings of a conference honoring Professor Dijen K. Ray-Chaudhuri on the occasion of his 65th birthday, K. T. Arasu and A. Seress, eds., pp. 207--214, de Gruyter, 2002.
  30. A quasi-symmetric 2-(49,9,6) design, J. Combin. Des., 10 (2002), 173--179 (with Masaaki Harada).
  31. Even unimodular Gaussian lattices of rank 12, J. Number Theory, 95 (2002), 77--94 (with Masaaki Kitazume).
  32. Four-weight spin models and Jones pairs, Trans. Amer. Math. Soc., 355 (2003), 2305--2325 (with Chris Godsil and Ada Chan).
  33. On Hadamard matrices of order 2(p+1) with an automorphism of odd prime order p, J. Combinatorial Designs, 11 (2003), 367--380 (with Daniel B. Dalan and Masaaki Hadara).
  34. Type II codes over F_2 + uF_2 and applications to Hermitian modular forms, Abh. Math. Sem. Univ. Hamburg, 73 (2003), 13--42.
    (with Eiichi Bannai, Masaaki Harada, Tomoyoshi Ibukiyama and Manabu Oura).
  35. Directed strongly regular graphs via coherent algebras, Linear Algebra Appl., 377 (2004), 83--109 (with Mikhail Klin, Mikhail Muzychuk and Paul-Hermann Zieschang).
  36. Spherical 5-designs obtained from finite unitary groups, European J. Combin., 25 (2004), 261--267.

  37. Extremal self-dual $[40,20,8]$ codes with covering radius $7$, Finite Fields and Their Applications, 10 (2004), 183--197 (with Masaaki Harada and Kenichiro Tanabe).

  38. On a $5$-design related to an extremal doubly-even self-dual code of length $72$, J. Combin. Theory, Ser.~A, 107 (2004), 143--146 (with Masaaki Harada, Masaaki Kitazume).

  39. A new quasi-symmetric $2$-$(56,16,6)$ design obtained from codes, Discrete Math., 29 (2004), 231--234 (with Vladimir D. Tonchev).
  40. The nonexistence of certain tight spherical designs, With an appendix by Y.-F.S. P\'etermann, Algebra i Analiz, 16 (2004), 1--23 (with Eiichi Bannai and Boris Venkov).
  41. On some self-dual codes and unimodular lattices in dimension $48$, European J. Combin., 26 (2005), 543--557 (with Masaaki Harada, Masaaki Kitazume and Boris Venkov).
  42. A characterization of designs related to an extremal doubly-even self-dual code of length $48$, Annals of Combinatorics, 9 (2005), 189--198 (with Masaaki Harada, Vladimir Tonchev).
  43. Some restrictions on weight enumerators of singly even self-dual codes, IEEE Trans. Inform. Theory, 52 (2006), 1266--1269 (with Masaaki Harada).
  44. Hyperplane partitions and difference systems of sets, J. Combin. Theory, Ser.~A, 113 (2006), 1689--1698 (with Ryoh Fuji-Hara and Vladimir Tonchev).
  45. On the covering radii of extremal doubly even self-dual codes, Adv. Math. Commun. 1 (2007), 251--256 (with Masaaki Harada).
  46. Simple abelian quadruple systems, J. Combin. Theory, Ser.~A 114 (2007), 1160--1164 (with Masanori Sawa).
  47. Determination of weight enumerators of binary extremal self-dual $[42,21,8]$ codes, Finite Fields and Their Applications, 14 (2008), 177--187 (with Stefka Bouyuklieva and Masaaki Harada).
  48. A new example of non-amorphous association schemes, Contributions to Discrete Mathematics 3, no. 2 (2008), 31--36 (with Takuya Ikuta). (link, magma program)

  49. There exists no self-dual $[24,12,10]$ code over ${F}_5$, Designs, Codes Cryptogr. 52 (2009), 125-127 (with Masaaki Harada).

  50. A complete classification of ternary self-dual codes of length 24, J. Combin. Theory, Ser.~A 116 (2009), 1063-1072. (with Masaaki Harada).

  51. Classification of ternary extremal self-dual codes of length 28, Math. Comp. 78 (2009), 1787-1796 (with Masaaki Harada and Boris Venkov).

  52. On the classification of self-dual ${Z}_k$-codes, the Twelfth IMA International Conference on Cryptography and Coding, 2009, Springer Lecture Notes in Comp. Sci. 5921, 78-90 (with Masaaki Harada).

  53. Mass formula for even codes over ${Z}_{8}$, the Twelfth IMA International Conference on Cryptography and Coding, 2009, Springer Lecture Notes in Comp. Sci. 5921, 65-77 (with Koichi Betsumiya, Rowena A.L. Betty).

  54. Mass formula for self-orthogonal codes over ${Z}_{p^2}$, Journal of Combinatorics, Information & System Sciences 34 (2009), 51-66 (with Rowena A. L. Betty).

  55. On graphs with complete multipartite mu-graphs, Discrete Math. 310 (2010), 1812-1819 (with Aleksandar Jurisic and Yuki Tagami). doi:10.1016/j.disc.2009.12.009

  56. Pseudocyclic association schemes and strongly regular graphs, European J. Combin. 31 (2010), 1513-1519 (with Takuya Ikuta). doi:10.1016/j.ejc.2009.08.003

  57. Classification of generalized Hadamard matrices $H(6,3)$ and quaternary Hermitian self-dual codes of length 18, Electronic J. Combin. 17 (2010), #R171 (with Masaaki Harada, Clement Lam and Vladimir D. Tonchev).

  58. Hamming graphs in Nomura Algebras, Linear Algebra Appl. 435 (2011), 330-341 (with Ada Chan).

  59. The twisted Grassmann graph is the block graph of a design, Innov. Incidence Geom. 12 (2011), 1-6 (with Vladimir D. Tonchev).

  60. Classification of quaternary hermitian self-dual codes of length 20, IEEE Trans. Inform. Theory 57 (2011), 3758-3762 (with Masaaki Harada). doi:10.1109/TIT.2011.2134330

  61. The codes and the lattices of Hadamard matrices, Europ. J. Combin. 33 (2012), 519-533 (with Hiroki Tamura). doi:10.1016/j.ejc.2011.11.007

  62. On the classification of weighing matrices and self-orthogonal codes, J. Combin. Des. 20 (2012), 40-57 (with Masaaki Harada). doi:10.1002/jcd.20295

  63. Steiner quadruple systems with point-regular automorphism groups, J. Stat. Theory Practice 6 (2012), 97-128 (with Masanori Sawa). doi:10.1080/15598608.2012.647536

  64. Classification of self-dual codes of length 36, Adv. Math. Commun. 6 (2012), 229-235 (with Masaaki Harada).

  65. A note on super Catalan numbers, Interdisciplinary Information Sciences 18 (2012), 23-24 (with Evangelos Georgiadis and Hajime Tanaka). doi:10.4036/iis.2012.23

  66. On triply even binary codes, J. London Math. Soc. 86 (2012), 1-16 (with Koichi Betsumiya). doi:10.1112/jlms/jdr054

  67. A complete classification of doubly even self-dual codes of length 40, Electronic J. Combin. 19 (2012), P18, 12 pages (with Koichi Betsumiya and Masaaki Harada).

  68. Spin models constructed from Hadamard matrices, Journal of Applied Mathematics and Computing 40 (2012), 231-248 (with Takuya Ikuta). doi:10.1007/s12190-012-0547-y

  69. Nomura algebra of nonsymmetric Hadamard models, Designs, Codes and Cryptogr. 65 (2012), 99-106 (with Takuya Ikuta). doi:10.1007/s10623-012-9609-2

  70. Upper bounds on cyclotomic numbers, Linear Algebra and Applications 438 (2012), 111-120 (with Koichi Betsumiya, Mitsugu Hirasaka and Takao Komatsu). doi:10.1016/j.laa.2012.06.045

  71. Residue codes of extremal Type II ${Z}_4$-codes and the moonshine vertex operator algebra, Math. Z. 274 (2013), 685-700 (with Masaaki Harada and Ching Hung Lam). doi:10.1007/s00209-012-1091-z

  72. On fat Hoffman graphs with smallest eigenvalue at least $-3$, Ars Math. Contemp. 7 (2014), 105-121 (with Hye Jin Jang, Jack Koolen and Tetsuji Taniguchi).

  73. Fat Hoffman graphs with smallest eigenvalue greater than $-3$, Discrete Applied Math. 176 (2014), 78-88 (with Yoshio Sano and Tetsuji Taniguchi). doi:10.1016/j.dam.2014.01.008

  74. Fat Hoffman graphs with smallest eigenvalue at least $-1-tau$, Ars Math. Contemp. 7 (2014), 247-262 (with Yoshio Sano and Tetsuji Taniguchi).

  75. Edge-signed graphs with smallest eigenvalue greater than $-2$, J. Combin. Theory, Series B 110 (2015), 90-111 (with Gary Greaves, Jack Koolen, Yoshio Sano and Tetsuji Taniguchi). doi:10.1016/j.jctb.2014.07.006

  76. On the smallest eigenvalues of the line graphs of some trees, Linear Algebra and its Applications 466 (2015), 501-511 (with Yoshio Sano and Tetsuji Taniguchi). doi:10.1016/j.laa.2014.10.037

  77. Complex Hadamard matrices contained in a Bose-Mesner algebra, Special Matrices 3 (2015), 91-110 (with Takuya Ikuta). doi:10.1515/spma-2015-0009

  78. Equiangular lines in Euclidean spaces, J. Combin. Theory, Series A 138 (2016), 208-235 (with Gary Greaves, Jack Koolen, and Ferenc Szollosi). doi:10.1016/j.jcta.2015.09.008

  79. On the classification of self-dual $[20,10,9]$ codes over $GF(7)$, Finite Fields and Their Applications 42 (2016), 57-66 (with Masaaki Harada). doi:10.1016/j.ffa.2016.07.004

  80. On the classification of self-dual ${Z}_k$-codes II, Interdisciplinary Information Sciences 17 (2016), 81-85 (with Masaaki Harada). doi:10.4036/iis.2015.R.01

  81. A note on the Brawley-Carlitz theorem on irreducibility of composed products of polynomials over finite fields, Lecture Notes in Comp. Sci. 10064, pp.~84-92, 2017 (with Hiroko Nakamura). doi:10.1007/978-3-319-55227-9_7

  82. Godsil-McKay switching and twisted Grassmann graphs, Designs, Codes Cryptogr. 84 (2017), 173-179. doi:10.1007/s10623-016-0244-1

  83. Self-dual codes and the non-existence of a quasi-symmetric $2$-$(37,9,8)$ design with intersection numbers $1$ and $3$, J. Combin. Des. 25 (2017), 469-476 (with Masaaki Harada and Vladimir Tonchev). doi:10.1002/jcd.21556

  84. On s-extremal singly even self-dual $[24k+8,12k+4,4k+2]$ codes, Finite Fields and Their Applications, 48 (2017), 306-317 (with Masaaki Harada). doi:information: 10.1016/j.ffa.2017.08.008

  85. On a lower bound for the Laplacian eigenvalues of a graph, Graphs Combin. 33 (2017), 1509-1519 (with Gary R. W. Greaves and Anni Peng). doi:10.1007/s00373-017-1835-y

  86. Transforming a matrix into a standard form, Interdisciplinary Information Sciences 23 (2017), 163-166 (with Pritta Etriana Putri). doi:10.4036/iis.2016.S.02

  87. A matrix approach to the Yang multiplication theorem, Australasian J. Combin. 70 (2018), 279-287 (with Pritta Etriana Putri).

  88. Butson-type complex Hadamard matrices and association schemes on Galois rings of characteristic 4, Special Matrices 6 (2018), 1-10 (with Takuya Ikuta). doi:10.1515/spma-2018-0001

  89. Nonexistence of certain singly even self-dual codes with minimal shadow, Electronic Journal of Combinatorics 25 (2018), #P1.13 (with Stefka Bouyuklieva and Masaaki Harada).

  90. Some restrictions on weight enumerators of singly even self-dual codes II, Interdisciplinary Information Sciences 24 (2018), 77-85 (with Masaaki Harada). doi:10.4036/iis.2017.R.03

  91. New strongly regular graphs from finite geometries via switching, Linear Algebra Appl. 580 (2019), 464-474 (with Ferdinand Ihringer). doi:10.1016/j.laa.2019.07.014

  92. Bent vectorial functions, codes and designs, IEEE Trans. Inform. 65 (2019), 7533-7541 (with Cunsheng Ding and Vladimir Tonchev). doi: 10.1109/TIT.2019.2922401

  93. Complex Hadamard matrices attached to a $3$-class nonsymmetric association scheme, Graphs Combin. 35 (2019), 1293-1304 (with Takuya Ikuta). doi:10.1007/s00373-019-02044-z

  94. Classification of self-dual codes of length 20 over ${Z}_4$ and length at most 18 over ${F}_2+u{F}_2$, IMACC 2019, Lecture Notes in Comp. Sci. 11929, 64-77 (with Rowena Betty). doi:10.1007/978-3-030-35199-1_4

  95. Complementary Ramsey numbers and Ramsey graphs, J. Indonesian Math. Soc. 25 (2019), no. 2, 146-153 (with Masashi Shinohara). doi:10.22342/jims.25.2.827.146-153

  96. Krein parameters of fiber-commutative coherent configurations, Algebra Colloquium 27 (2020), 1-10 (with Keiji Ito). doi:10.1142/S1005386720000024

  97. Ternary codes, biplanes, and the nonexistence of some quasi-symmetric and quasi-3 designs, J. Combinatorial Des. 28 (2020), 745-752 (with Vladimir D. Tonchev). doi:10.1002/jcd.21740

  98. Signed analogue of line graphs and their smallest eigenvalues, J. Graph Theory 98 (2021), 309-325 (with Alexander L. Gavrilyuk, Yoshio Sano and Tetsuji Taniguchi). doi:10.1002/jgt.22699

  99. A note on Assmus-Mattson type theorems, Designs, Codes and Cryptogr. 89 (2021), 843-858 (with Tsuyoshi Miezaki and Hiroyuki Nakasora) doi:10.1007/s10623-021-00848-w

  100. Maximality of Seidel matrices and switching roots of graphs, Graphs and Combin. 37 (2021), 1491-1507 (with Meng-Yue Cao, Jack H. Koolen and Kiyoto Yoshino). doi.org/10.1007/s00373-021-02359-w

  101. Bordered complex Hadamard matrices and strongly regular graphs, Interdisciplinary Information Sciences 27 (2021), 41-56 (with Takuya Ikuta). doi.org/10.4036/iis.2020.R.03

  102. Quasi-symmetric $2$-$(41,9,9)$ designs and doubly even self-dual codes of length $40$ Applicable Algebra in Engineering, Communication and Computing 33 (2022), 855-866 (with Vladimir D. Tonchev). doi.org/10.1007/s00200-022-00543-w

  103. Maximal digraphs whose Hermitian spectral radius is at most $2$ (with Alexander Gavrilyuk), Linear Algebra Appl. 658 (2023), 331-349. doi.org/10.1016/j.laa.2022.11.007

  104. Extended double covers of non-symmetric association schemes of class $2$ (with Takuya Ikuta), in ``Algebraic Combinatorics and the Monster Group'', pp.518-526, edited by A.A.~Ivanov, Cambridge University Press, 2023.

  105. Classification of Extremal Type II ${Z}_4$-codes of Length $24$, (with Rowena A.L. Betty), Designs, Codes and Cryptography, 92 (2024), 771-785. doi.org/10.1007/s10623-023-01293-7

  106. Convex subgraphs and spanning trees of the square cycles, (with Yuuho Tanaka), Australasian Journal of Combinatorics 88 (2024), 204-211.

  107. Jacobi polynomials and harmonic weight enumerators of the first-order Reed-Muller codes and the extended Hamming codes (with Tsuyoshi Miezaki), Des. Codes Cryptogr. 92 (2024), 1041-1049. doi.org/10.1007/s10623-023-01327-0

  108. A note on $t$-designs in isodual codes, (with Madoka Awada, Tsuyoshi Miezaki, and Hiroyuki Nakasora), Finite Fields Appl. 95 (2024), 102366. doi.org/10.1016/j.ffa.2024.102366

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