[Researched paper]
[1] Imbedding of a complex projective space similar to Segre imbedding, Arch. Math. (Basel) 37 (1981), no.6, 556-560.
[2] Imbedding of a complex projective space defined by monomials of same degree, (with Y. Shimizu), Math. Z. 179 (1982), no.3, 337-344.
[3] On submanifolds all of whose geodesics are circles in a complex space form, (with N. Sato), Kodai Math. J. 6 (1983), no.2, 157-166.
[4] Real hypersurfaces of complex projective spaces, Math. Ann. 263 (1983), no.4, 473-478.
[5] Isotropic immersions with parallel second fundamental form, Canad. Math. Bull. 26 (1983), no.3, 291-296.
[6] Isotropic immersions with parallel second fundamental form II, Yokohama Math.J. 31 (1983), no.1-2, 131-138.
[7] Real hypersurfaces of a complex projective space II, Bull. Austra. Math. Soc. 30 (1984), no1, 123-127.
[8] Isotropic immersions, Canad. J. Math. 38 (1986), no.2, 416-430.
[9] Remarks on isotropic immersions, Yokohama Math. J. 34 (1986), no.1-2, 83-90.
[10] Constant mean curvature submanifolds of higher codimensions, (with T. Maebashi), Kodai Math. J. 9 (1986), no.2,175-178.
[11] Helical geodesic immersions into complex space forms, (with Y. Ohnita), Geom. Dedicata 30 (1989), no.1, 93-114.
[12] On real hypersurfaces of a complex projective space, (with M. Kimura), Math. Z. 202 (1989), no.3, 299-311.
[13] Surfaces with constant Kaehler angle all of whose geodesics are circles in a complex space form, (with S. Udagawa), Tokyo J. Math. 13 (1990), no.2, 341-351.
[14] Real hypersurfaces of a complex projective space in terms of holomorphic distribution, (with S. Udagawa), Tsukuba J. Math. 14 (1990), no.1, 39-52.
[15] On real hypersurfaces of a complex projective space II, (with M. Kimura), Tsukuba J.Math. 15 (1991), no.2, 547-561.
[16] Characterizations of geodesic hyperspheres in a complex projective space in terms of Ricci tensors, (with M. Kimura), Yokohama Math. J. 40 (1992), no.1, 35-43.
[17] On slant immersions into Kaehler manifolds, (with Y. Ohnita and S. Udagawa), Kodai Math. J. 16 (1993), no.2, 205-219.
[18] On real hypersurfaces of a complex projective space III, (with M. Kimura), Hokkaido Math. J. 22 (1993), no.1, 63-78.
[19] Ricci tensors of real hypersurfaces in a complex projective space, Proc. Amer. Math. Soc. 122 (1994), no.4, 1229-1235.
[20] Isotropic immersions into a real space form, (with K. Tsukada), Canad. Math. Bull. 37 (1994), no.2, 245-253.
[21] Geometry of submanifolds in terms of behavior of geodesics, (with K. Ogiue), Tokyo J. Math. 17 (1994), no.2, 347-354.
[22] Lie derivatives on homogeneous real hypersurfaces of type B in a complex projective space, (with U-Hang Ki and Y. J Suh), Yokohama Math. J. 42 (1994), no.2, 121-131.
[23] Lie derivatives on real hypersurfaces in a complex projective space, (with M. Kimura), Czechoslovak Math. J. 45 (1995), no.1, 135-148.
[24] Circles in a complex projective space, (with T. Adachi and S. Udagawa), Osaka J. Math. 32 (1995), no.3, 709-719.
[25] Extrinsic characterizations of circles in a complex projective space imbedded in a Euclidean space, (with B.-y. Chen), Tokyo J. Math. 19 (1996), no. 1, 169-185.
[26] Holomorphic helices in a complex space form, (with T. Adachi), Proc. Amer. Math.. Soc. 125 (1997), 1197-1202.
[27] Global behaviours of circles in a complex hyperbolic space, (with T.Adachi), Tsukuba J. Math. 21 (1997), 29-42.
[28] Characterizations of geodesic hyperspheres in a complex projective space by observing the extrinsic shape of geodesics, (with K.Ogiue), Math. Z. 225 (1997), 537-542.
[29] Extrinsic shape of circles and standard imbeddings of projective spaces, (with T. Adachi and K. Ogiue), Manuscripta Math. 93 (1997), 267-272.
[30] Extrinsic shape of circles and the standard imbedding of a cayley projective plane, (with T.Adachi and K. Ogiue), Hokkaido Math. J. 26 (1997), 411-419.
[31] Circular geodesic submanifolds with parallel mean curvature vector in a non-flat complex space form, (with R. Takagi), Proc. Japan Acad. 73 (1997), 55-57.
[32] Length spectrum of circles in a complex projective space, (with T. Adachi), Osaka J. Math. 35 (1998), 553-565.
[33] Notes on extrinsic spheres, (with U-Hang Ki), Korean Math. Bull. 35 (1998), 433-439.
[34] A construction of closed helices with self-intersections in a complex projective space by using submanifold theory, (with T. Adachi), Hokkaido Math. J. 28 (1999), 133-145.
[35] Circular helices in a standard sphere, (with T. Adachi), New Zealand J. Math. 28 (1999), 1-6.
[36] A characterization of all homogeneous real hypersurfaces in a complex projective space by observing the extrinsic shape of geodesics, (with T. Adachi and M. Kimura), Arch. Math. (Basel) 73 (1999), 303-310.
[37] Geometric meaning of isoparametric hypersurfaces in a real space form, (with M. Kimura), Canadian Math. Bull. 43 (2000), 74-78.
[38] Geometry of holomorphic distributions of real hypersurfaces in a complex projective space, (with U-Hang Ki and M. Kimura), Czechoslovak Math. J. 51 (2001), 197-204.
[39] Simpleness and closedness of circles in compact Hermitian symmetric spaces, (with T. Adachi and S. Udagawa), Tsukuba J. Math. 24 (2000), 1-13.
[40] Hopf hypersurfaces with constant principal curvatures in complex projective or complex hyperbolic spaces, (with B.-y. Chen), Tokyo J. Math. 24 (2001), 133-152.
[41] Space forms from the viewpoint of their geodesic spheres, (with T. Adachi), Bull. Australian Math. Soc. 62 (2000), 205-210.
[42] Length spectrum of geodesic spheres in a non-flat complex space form, (with T. Adachi and M. Yamagishi), J. Math. Soc. Japan 54 (2002), 373-408.
[43] A characterization of extrinsic spheres in a Riemannian manifold, (with M. Kozaki), Tsukuba J. Math. 26 (2002), 291-297.
[44] Curvature-adapted real hypersurfaces in quternionic space forms, (with T. Adachi), Kodai Math. J. 24 (2001), 98-119.
[45] Quaternionic distribution of curvature-adapted real hypersurfaces in a quternionic hyperbolic space, (with T. Adachi), Journal of Geometry, 75 (2002), 1-14.
[46] Some characterizations of quaternionic space forms, (with T. Adachi), Proc. Japan Acad. 76 (2000), Ser. A, 168-172.
[47] Real hypersurfaces in nonflat complex space forms are irreducible, (with B.-y. Chen), Osaka J. Math. 40 (2003), 121-138.
[48] A characterization of the second Veronese embedding into a complex projective space, (with T. Adachi), Proc. Japan Acad. 77 (2001), Ser. A, 99-102.
[49] Characterization of totally geodesic K\"ahler immersions, (with K. Suizu and T. Adachi), Hokkaido Math. J. 31 (2002), 629-641.
[50] A characterization of Veronese imbeddings into complex projective spaces, (with K. Suizu and T. Adachi), Math. Reports Acad. Sci. Royal Soc. Canada 24 (2002), no. 2, 61-66.
[51] On some isotropic submanifolds in spheres, Proc. Japan Acad. 77 (2001), Ser. A, 173-175.
[52] A characterization of constant isotropic immersions by circles, Arch. Math. (Basel) 81 (2003), 90-95.
[53] Geometry of ordinary helices in a complex projective space, (with T. Adachi and S. Udagawa), Hokkaido Math. J. 33 (2004), 233-246.
[54] Characterization of totally umbilic hypersurfaces in a space form by circles, (with T. Adachi), Czechoslovak Math. J. 55 (2005), 203-207.
[55] Characterizations of space forms by circles on their geodesic spheres, (with T. Adachi), Proc. Japan Acad. 78 (2002), Ser. A, 143-147.
[56] Real hypersurfaces some of whose geodesics are plane curves in nonflat complex space forms, (with T. Adachi and M. Kimura), Tohoku Math. J. 57 (2005), 223-230.
[57] Holomorphic helix of proper order 3 on a complex hyperbolic plane, (with T. Adachi), Topology and its Applications (Elsevier Science) 146/147 (2005), 201-207.
[58] Congruence theorem of geodesics on some naturally reductive Riemannian homogeneous manifolds, (with T. Adachi), Math. Reports Acad. Sci. Royal Soc. Canada 26 (2004), 11-17.
[59] 階数１の対称空間における曲線と部分多様体, (with T. Adachi), 数学５６巻第１号（２００４年１月）, 論説３３頁ー４８頁. Curves and submanifolds in rank one symmetric spaces, (with T. Adachi), Amer. Math. Soc., A Translation of 数学, Sugaku Expositions 19 (2006), 217-235.
[60] Characterization of complex space forms in terms of geodesics and circles on their geodesic spheres, (with T. Adachi), Nihonkai Math. J. 14 (2003), 95-98.
[61] Characteristic vector fields on geodesic spheres in a complex space form, (with T. Adachi), Bull. Calcutta Math. Soc. 99 (2007), 411-414.
[62] Characterization of totally $\eta$-umbilic real hypersurfaces in nonflat complex space forms by some inequality, (with T. Itoh), Proc. Japan Acad. Ser. A. 80 (2004), 61-64.
[63] Ruled real hypersurfaces in a nonflat quaternionic space form, (with T. Adachi and S. Udagawa), Monatshefte f\"ur Mathematik 145 (2005), 179-190.
[64] Shape operators and structure tensors of real hypersurfaces in nonflat quaternionic space forms, (with T. Adachi), Bull. Polish Acad. Sci. Math. 52 (2004), 319-329.
[65] Study of isotropic immersions, (with N. Boumuki), Kyungpook Math. J. 45 (2005), 363-394.
[66] Isoparametric hypersurfaces with less than 4 principal curvatures in a sphere, (with T. Adachi), Colloquium Math. 105 (2006), 143-148.
[67] Totally geodesic immersions of K\"ahler manifolds and K\"ahler Frenet curves, (with H. Tanabe), Math. Z. 252 (2006), 787-795.
[68] Schur's lemma for K\"ahler manifolds, (with T. Adachi and S. Udagawa), Arch. Math. (Basel) 90 (2008), 163-172.
[69] Integral curves of the characteristic vector field of real hypersurfaces in nonflat complex space forms, (with T. Adachi), Geometriae Dedicata. 123 (2006), 65-72.
[70] Geodesic spheres in a nonflat complex space form and their integral curves of characteristic vector fields, (with T. Adachi and Y.H. Kim), Hokkaido Math. J. 36 (2007), 353-363.
[71] Practical criterion for some submanifolds to be totally geodesic, (with Y.H. Kim), Monatshefte f\"ur Mathematik 149 (2006), 233-242.
[72] Complex space forms and geodesics on their geodesic spheres, (with T. Adachi), Far East J. Math. Sci. (FJMS) 18 (2005), 277-284.
[73] A useful characterization of some real hypersurfaces in a nonflat complex space form, (with T. Itoh), Bull. Polish Acad. Sci. Math. 54 (2006), 125-136.
[74] Characterization of parallel isometric immersions of space forms into space forms in the class of isotropic immersions, (with S. Udagawa), Canadian J. Math. 61 (2009), 641-655.
[75] Characterization of complex space forms in terms of characteristic vector fields on geodesic spheres, C. R. Math. Rep. Acad. Sci. Canada 28 (2006), 114-120.
[76] Characterizations of type $A_2$ hypersurfaces in a complex projective space, (with T. Adachi), Bull. Aust. Math. Soc. 77 (2008), no. 1, 1--8.
[77] A characterization of the homogeneous minimal ruled real hypersurface in a complex hyperbolic space, (with T. Adachi and Y.H. Kim), J. Math. Soc. Japan 61 (2009), 315-325.
[78] A characterization of the homogeneous real hypersurface of type (B) with two distinct constant principal curvatures in a complex hyperbolic space, Sci. Math. Japonicae 68 (2008), 1-10.
[79] Extrinsic geodesics and hypersurfaces of type (A) in a complex projective space, (with T. Adachi), Tohoku Math. J. 60 (2008), 597-605.
[80] Geometric meaning of Sasakian space forms from the viewpoint of submanifold theory, (with T. Adachi and M. Kameda), Kodai Math. J. 33 (2010), 383-397.
[81] Sasakian curves on hypersurfaces in a nonflat complex space form, (with T. Adachi), Results in Math. 56 (2009), 489-499.
[82] Three real hypersurfaces some of whose geodesics are mapped to circles with the same curvature in a nonflat complex space form, (with K. Okumura), Geometriae Dedicata.156 (2012), 71-80.
[83] Real hypersurfaces which are contact in a nonflat complex space form, (with T. Adachi and M. Kameda), Hokkaido Math. J. 40 (2011), 205-217.
[84] Real hypersurfaces with $\phi$-invariant shape operator in a complex projective space, (with H. Naitoh), Glasgow Math. J. 53 (2011), 347-358.
[85] Real hypersurfaces in a nonflat complex space form and their almost contact metric structures, (with Y.H. Kim), Colloquium Mathematicum 124 (2011), 117-131.
[86] A homogeneous submanifold with nonzero parallel mean curvature vector in Euclidean sphere, (with S. Udagawa), J. Geom. 102 (2011), 123-131.
[87] Totally $\eta$-umbilic hypersurfaces in a nonflat complex space form and their almost contact metric structures, (with B.H. Kim), Sci. Math. Japonicae 72 (2010), 289-296.
[88] Geometry of the horosphere
in a complex hyperbolic space, Differential Geometry and its Applications 29
(2011), S246-S250.
[89] A certain two-parameters family of helices of order
6 in Euclidean sphere, (with B.H. Kim), Differential Geometry and its
Applications 35 (2014), 117-124.
[90] The real hypersurface of type (B) with two distinct
principal curvatures in a complex hyperbolic space, (with K. Yamashita), Kodai Math. J. 37 (2014), 24-33.
[91] A characterization of minimal real hypersurfaces of
type $({\rm A}_2)$ in a complex projective space in terms of their geodesics,
(with Y. Taniguchi), Sci. Math. Japonicae 74 (2011),
139-144.
[92] Characterizations of geodesic hyperspheres in a nonflat complex space form, (with T. Adachi and Y.H. Kim),
Glasgow Math. J. 55 (2013), 217-227.
[93] Hopf hypersurfaces with
$\eta$-parallel Ricci tensors in a nonflat complex
space form, Sci. Math. Japonicae 76 (2013), 449-456.
[94] Congruence classes of minimal ruled real
hypersurfaces in a nonflat complex space form, (with
T. Adachi and T. Bao), Hokkaido Math. J. 43 (2014), 1-14.
[95] Naturally reductive homogeneous real hypersurfaces
in a nonflat complex space form, (with H. Tamaru),
Topology and its Applications 196 (2015), 675-683.
[96] Normal real hypersurfaces in a nonflat
complex space form, (with B.H. Kim and H. Tanabe), Sci. Math. Japonicae 77 (2014), 159-167.
[97] Nonnegatively curved geodesic spheres in a complex
hyperbolic space, Math. Reports Acad. Sci. Royal Soc. Canada 34 (2013), 38-44.
[98] Sectional curvatures of geodesic spheres in a
complex hyperbolic space, (with T. Kajiwara), Kodai Math. J. 38 (2015), 604-619.
[99] Ruled real hypersurfaces having the same sectional
curvature as that of an ambient nonflat complex space
form, (with H. Tanabe and Y.H. Kim), Kodai Math. J.
39 (2016), 119-128.
[100] A characterization of homogeneous real
hypersurfaces of types (C), (D) and (E) in a complex projective space, (with H.
Tanabe), Differential Geometry and its Applications 54 (2017), 2-10.
[101] A characterization of the homogeneous ruled real
hypersurface in a complex hyperbolic space in terms of the first curvature of
some integral curves, (with H. Tanabe), Arch. Math. (Basel) 105 (2015),
593-599.
[102] Characterizations of three homogeneous real
hypersurfaces in a complex projective space, (with M Kimura), Hokkaido Math. J.
47 (2018), 1-26.
[103] A characterization of a certain real hypersurface
of type $({\rm A}_2)$ in a complex projective space, (with B.H. Kim and I.B.
Kim), Czechoslovak Math. J. 67
(2017), 271–278.
[104] Curvature properties of homogeneous real
hypersurfaces in nonflat complex space forms, (with
H. Tamaru and H. Tanabe), Kodai Math. J. 41 (2018),
315-331.
[105] Sectional curvatures of ruled real hypersurfaces
in a complex hyperbolic space, (with H. Tanabe), Differential Geometry and its
Applications 51 (2017), 1-8.
[106] Integral curves of the characteristic vector field
of minimal ruled real hypersurfaces in non-flat complex space forms, (with M.
Kimura and H. Tanabe), to appear in Hokkaido Math. J.
[107] Characterizations of Berger spheres from the
viewpoint of submanifold theory, (with B.H. Kim and I.B. Kim), Glasgow Math. J.
62 (2020), 137-145.
[108] Geometric properties of Lie hypersurfaces in a
complex hyperbolic space, (with Y.H. Kim and H. Tanabe), Czechoslovak Math. J.
69 (144) (2019), 983-996.
[109] The homogeneous ruled real hypersurface in a
complex hyperbolic space, (with M. Kimura and H. Tanabe), to appear in J.
Geometry.
[110] Generating curves of minimal ruled real
hypersurfaces in a nonflat complex space form, (with H. Tanabe and S. Udagawa), Canadian Math. Bull. 62 (2019), 383-392.
[111] New construction of ruled real hypersurfaces in a
complex hyperbolic space and its applications, (with M. Kimura and H. Tanabe),
Geom. Dedicata, online.
[112] Length spectrum of complete simply connected Sasakian space forms, (with T. Adachi), to appear in
Differential geometry and its Applications.
[113] Ricci curvatures and scalar curvatures of minimal
homogeneous real hypersurfaces in a nonflat complex space
form, (with M. Kimura and H. Tanabe), to appear in Sci. Math. Japonicae.
[114] Sectional curvatures of homogeneous real
hypersurfaces of types (A) and (B) in a complex projective space, (with M.
Kimura and H. Tanabe), preprint.
[Conference paper]
[1] Second fundamental form of real hypersurfaces in a
complex projective space.Nonassociative algebras and
related topics (Hiroshima,1990), 139-153. World Sci. Publishing, River Edge,
NJ, 1991.
[2] Geometry of real hypersurfaces in a complex
projective space, Aspects of Complex Analysis, Differential Geometry,
Mathematical Physics and Applications, Bulgaria, September 1998, World
Scientific, 160-171.
[3] Differential geometry of circles in a complex
projective space, (with T. Adachi), Proceedings of the Second Meeting
Quaternionic Structures in Mathematics and Physics, Rome, Italy 6-10 September
1999, World Scientific, 253-263.
[4] Circles and K\"ahler
immersions, (with T. Adachi), Trends in Complex Analysis, Differential Geometry
and Mathematical Physics, Bulgaria, September 2002, World Scientific 123-134.
[5] Three theorems on isotropic immersions, Trends in
Complex Analysis, Differential Geometry and Mathematical Physics, Bulgaria,
September 2002, World Scientific 116-122.
[6] Ordinary helices and Riemannian geometry, (with T.
Adachi), Contemporary aspects of complex analysis, differential geometry and
mathematical physics, August 2004, Plovdiv, Bulgaria, World Sci. 14-24.
[7] Totally umbilic hypersurfaces and isoparametric hypersurfaces in space forms, (with M.
Kimura), Contemporary aspects of complex analysis, differential geometry and
mathematical physics, August 2004, Plovdiv, Bulgaria, World Sci. 149-157.
[8] Real hypersurfaces in a nonflat
complex space form from the viewpoint of their geodesics, (with T. Adachi),
Topics in almost Hermitian geometry and related fieds,
2004, World Sci. 157-169.
[9] Type two Killing helices of proper order four on a
complex projective plane, (with T. Adachi), Topics in Differential geometry,
complex analysis and Mathematical Physics, 2006, World Sci. 9-14.
[10] Sectional curvatures of some homogeneous real
hypersurfaces in a complex projective space, (with M. Kimura), Topics in
Differential geometry, complex analysis and Mathematical Physics, 2006, World
Sci. 196-204.
[11] Generalized Veronese manifolds and isotropic
immersions, (with S. Udagawa), Differential Geometry
and its Applications, Proc. Conf., in Honour of
Leonhard Euler, Olomouc, August 2007, 2008 World Sci. 197-202.
[12] A characterization of Clifford minimal
hypersurfaces in terms of their geodesics, Topics in Differential geometry,
complex analysis and Mathematical Physics, 2008, World Sci. 167-173.
[13] Homogeneous submanifolds and homogeneous curves in
space forms, Differential geometry of submanifolds and its related topics,
2013, World Sci. 1-15.
[14] Sectional curvatures of ruled real hypersurfaces in
a nonflat complex space form, (with H. Tanabe),
Differential geometry of submanifolds and its related topics, 2013, World Sci.
113-118.
[口頭発表]
[1] 茨城における「幾何学研究集会」で講演, 1981年1月.
[2] 仙台における「幾何学研究集会」で講演, 1983年11月.
[3] 盛岡における「微分幾何学シンポジューム」で講演,
1984年10月.
[4] 熊本大学における「幾何学研究集会」で講演, 1985年6月.
[5] 佐渡島における「幾何学研究集会」で講演, 1986年9月.
[6] 鹿児島大学における「幾何学研究集会」で講演, 1987年11月.
[7] 広島における「幾何学国際研究集会」で講演, 1990年8月.
[8] 新潟大学における「微分幾何学シンポジューム」で講演,
1991年7月.
[9] 横浜市立大学における「幾何学研究集会」で講演, 1991年9月.
[10] 筑波大学における「微分幾何学シンポジューム」で講演,
1994年7月.
[11] テサロニッキ（ギリシャ）における「国際研究集会」で講演,
1996年5月.
[12] 日本工大における「幾何学研究集会」で講演, 1996年10月.
[13] デトロイト（米国）における AMS Meeting で講演, 1997年5月.
[14] 島根大学における「幾何学研究集会」で講演, 1997年9月.
[15] バルナ（ブルガリア）における「国際研究集会」で講演,
1998年9月.
[16] 東京大学における「微分幾何学シンポジューム」で講演,
1999年8月.
[17] ローマ（イタリア）における「国際研究集会」で講演,
1999年9月.
[18] 東京都立大学における「幾何学研究集会」で講演,
1999年9月.
[19] 筑波大学における「幾何小研究会」で講演, 1999年12月.
[20] 上智大学における「幾何学研究集会」で講演, 2000年2月.
[21] 久住における「幾何学研究集会」で講演, 2000年9月.
[22] 越後湯沢における「幾何学研究集会」で講演, 2000年11月.
[23] 東京都立大学における「幾何学国際研究集会」で講演,
2001年12月,
[24] 島根大学における「国際研究集会」で講演, 2002年6月.
[25] バルナ（ブルガリア）における「国際研究集会」で講演,
2002年9月.
[26] 筑波大学における「幾何学研究集会」で講演, 2002年12月.
[27] コルカタ（インド）における「国際研究集会」で講演,
2003年2月.
[28] 東京都立大学における「幾何学国際研究集会」で講演,
2003年12月.
[29] 東京都立大学における「微分幾何学シンポジューム」で講演,
2004年8月.
[30] プロビデフ大学（ブルガリア）における「国際研究集会」で講演, 2004年9月.
[31] チョンブック大学（韓国）における「大韓数学会」で特別講演, 2004年10月.
[32] 新潟大学における「幾何学国際研究集会」で講演,
2004年11月.
[33] ソフィア（ブルガリア）における「国際研究集会」で講演,
2006年8月.
[34] 京都大学数理解析研究所における「幾何学研究集会」で講演,
2007年7月.
[35] オロモーツ（チェコ共和国）における「DGA 2007 国際研究集会」で講演, 2007年8月.
[36] 阿蘇における「幾何学研究集会」で講演, 2007年9月.
[37] 広島大学における「幾何学研究集会」で講演, 2007年10月.
[38] 越後湯沢における「幾何学研究集会」で講演, 2007年11月.
[39] 千葉工業大学における「幾何学研究集会」で講演,
2008年3月.
[40] ソフィア（ブルガリア）における「国際研究集会」で講演,
2008年8月,
[41] 新潟大学における「幾何学研究集会」で講演, 2008年11月.
[42] コルカタ（インド）における「国際研究集会」で講演,
2008年12月.
[43] 熊本大学教育学部における「幾何学研究集会」で講演,
2009年1月.
[44] クアラルンプール（マレーシア）における「アジア数学会」で講演, 2009年6月.
[45] 梨花女子大学（韓国・ソウル）における「国際研究集会」で講演, 2010年8月.
[46] ブルノ（チェコ共和国）における「DGA 2010 国際研究集会」で講演, 2010年8月.
[47] 東京理科大学における「幾何学研究集会」で講演,
2010年9月.
[48] 熊本大学教育学部における「幾何学研究集会」で講演,
2011年1月.
[49] 佐賀大学における「幾何学研究集会」で講演, 2012年8月.
[50] 広島大学における「幾何学研究集会」で講演, 2012年10月.
[51] NIMS 研究所（韓国・大田）における「国際研究集会」で講演, 2013年2月.
[52] ブルノ（チェコ共和国）における「DGA 2013 国際研究集会」で講演, 2013年8月.
[53] 島根大学における「国際研究集会」で特別講演, 2013年9月.
[54] マンガリア（ルーマニア）における「国際研究集会」で講演,
2014年８月.
[55] 越後湯沢幾何学研究集会で講演, 2015年11月.
[56] 全州国立大学校（韓国・全州）における「国際研究集会」で講演, 2016年6月.
[57] ブルノ（チェコ共和国）における「DGA 2016 国際研究集会」で講演, 2016年7月.
[58] トラブゾン（トルコ）における 「ICRAPAM 2018 国際研究集会」で講演,
2018 年8月.
[59] フラデツ・クラローベ（チェコ共和国）における「DGA
2019 国際研究集会」で講演, 2019年9月.