Junichi Fujii

(藤井淳一)

Profile Information

Affiliation: Special Appointed Professor, Division of Math, Sciences, and Information Technology in Education, Osaka Kyoiku University

Degree: Master of Education(Osaka Kyoiku University)
教育学修士(大阪教育大学)
PhD (Science)(Science University of Tokyo)
理学博士(東京理科大学)

Other name(s) (e.g. nickname): Jun Ichi Fujii
Researcher number: 60135770
J-GLOBAL ID: 200901073543532288
researchmap Member ID: 1000032188

External link: http://www.osaka-kyoiku.ac.jp/~fujii/lhtml/index-j.html

Research Interests

Research Areas

Research History

Apr, 2021 - Present

大阪教育大学・名誉教授
Apr, 2021 - Mar, 2024

大阪教育大学・特任教授
Nov, 2006 - Mar, 2021

大阪教育大学・教授
Apr, 1995 - Oct, 2006

大阪教育大学・助教授
Apr, 1988 - Mar, 1995

大阪教育大学・講師

Education

Apr, 1978 - Mar, 1980

数学教育, Graduate School, Division of Education, Osaka Kyoiku University
Apr, 1974 - Mar, 1978

小学校教員養成課程(数学科), Faculty of Education, Osaka Kyoiku University

Papers

174

行列表現をめぐって

瀬尾祐貴, 富永雅, 藤井淳一, 藤井正俊, 松本明美

数学教育研究, 32(32) 43-52, 2002
Kolmogorov's complexity for positive definite matrices

JI Fujii, M Fujii

LINEAR ALGEBRA AND ITS APPLICATIONS, 341 171-180, Jan, 2002 Peer-reviewed

Based on Kolmogorov's idea, complexity of positive definite matrices with respect to a unit vector is defined. We show that the range of the complexity coincides with the logarithm of its spectrum and the order induced by the complexity is equivalent to the spectral one. This order implies the reversed one induced by the operator entropy. (C) 2002 Elsevier Science Inc. All rights reserved.
Operator inequalities of Malamud and Wielandt

JI Fujii, R Nakamoto, Y Seo

LINEAR ALGEBRA AND ITS APPLICATIONS, 326(1-3) 101-109, Mar, 2001 Peer-reviewed

We show that the Wielandt operator inequality and the Malamud one are equivalent and discuss some variations of them. From this point of view, we give also a proof of Malamud's multivariable inequality with its variations. (C) 2001 Elsevier Science Inc. All rights reserved.
Jensen の不等式をめぐって

瀬尾祐貴, 富永雅, 藤井淳一, 藤井正俊, 松本明美

数学教育研究, 31(31) 63-70, 2001
非可換から可換へ Specht ratio の場合

瀬尾祐貴, 富永雅, 藤井淳一, 藤井正俊, 松本明美

数学教育研究, 30(30) 1-14, 2000
An analogue to Hansen’s theory of generalized L¨owner’s functions

Fujii, Jun Ichi, Fujii, Masatoshi

Mathematica Japonica, 35(2) 327-330, 1999 Peer-reviewed
Operator inequalities for Schwarz and Hua

Fujii, Jun Ichi

Sciantiae Mathematicae, 2(3) 263-268, 1999 Peer-reviewed
Simplified proof of characterization of chaotic order via Specht's ratio

Fujii, Jun Ichi, Furuta, Takayuki, Yamazaki, Takeaki, Yanagida, Masahiro

Scientiae Mathematicae, 2(1) 63-64, 1999 Peer-reviewed
Bhatia-Kittaneh's operator norm inequality

Fujii, Jun Ichi, Fujii, Masatoshi

Mathematica Japonica, 49(1) 91-92, 1999 Peer-reviewed
Determinant for positive operators

Fujii, Jun Ichi, Seo, Yuki

Scientiae Mathematicae, 1(2) 153-156, 1998 Peer-reviewed
Determinant for positire operators and Specht's theorem

Fujii, Jun Ichi, Izumino, Saichi, Seo, Yuki

Scientiae Mathematicae, 1(3) 307-310, 1998 Peer-reviewed
On parametrized operator means dominated by power ones

Fujii, Jun Ichi, Seo, Yuki

Scientiae Mathematicae, 1(3) 301-306, 1998 Peer-reviewed
An operator version of the Wilf-Diaz-Matcalf inequality

Fujii, Jun Ichi, Furuta, Takayuki

Nihonkai Mathemetical Journal, 9(1) 47-52, 1998 Peer-reviewed
Entropy and coding for graphs

Fujii Jun Ichi, Seo Yuki

International Journal of Mathematical and Statistical Science, 6(1) 63-77, 1997 Peer-reviewed
アメリカの微積分改革運動についての一報告数学教育の危機に際して

藤井淳一

数学教育研究, 24, 1995
Similarity invariants of explications of graphs

Fujii, Jun Ichi

Mathematica Japonica, 42(2) 233-237, 1995 Peer-reviewed
The Marcus-Khan theorem for Hilbert space operators

Fujii, Jun Ichi

Mathematica Japonica, 41(3) 531-535, 1995 Peer-reviewed
Graphs and tensor product of operators

Fujii, Junichi, Seo, Yuki

Mathematica Japonica, 41(2) 245-252, 1995 Peer-reviewed
Interpolational paths and their derivatives

Fujii, Jun Ichi, Kamei, Eizaburo

Mathematica Japonica, 39(3) 557-560, 1994 Peer-reviewed
Fuzzy’s but walking shadow

Fujii, Jun Ichi, Nakamura, Masahiro

Mathematica Japonica, 40(2) 255-257, 1994 Peer-reviewed
風にそよいで

中村正弘, 藤井淳一

数学教育研究, 23, 1993
Graphs and numerical center of mass

Fujii, Jun Ichi, Seo, Yuki

Mathematica Japonica, 38(2) 351-359, 1993 Peer-reviewed
Theorems of Williams and Prasanna

Fujii, Jun Ichi, Fujii, Masatoshi

Mathematica Japonica, 38(1) 35-37, 1993 Peer-reviewed
Conrergence to the Infimum Projection

Fujii, Jun Ichi

Mathematica Japonica, 38(4) 767-770, 1993 Peer-reviewed
Entropy of Graphs

Fujii, Jun Ichi

Mathematica Japonica, 38(1) 39-46, 1993 Peer-reviewed
Norm Inequalities Equiralent to Heinz Inequality

Fujii, Jun Ichi, Fujii, Masatoshi, Furuta, Takayuki, Nakamoto, Ritsuo

Proceedings of the American Mathematical Society, 118(3) 827-830, 1993 Peer-reviewed
OPERATOR MEANS AND RANGE INCLUSION

JI FUJII

LINEAR ALGEBRA AND ITS APPLICATIONS, 170(C) 137-146, Jun, 1992 Peer-reviewed

We prove the range inclusions ran A1/2 + ran B1/2 superset-or-equal-to ran(Am B)1/2 superset-or-equal-to ran A1/2 and ran B1/2 for an operator mean m. An equality condition in each inclusion is given by using the representing function f(x) = 1 mx and F(x) = xm 1. Further we show that an operator mean m is majorized by a geometric mean if and only if ran(Am B) superset-or-equal-to ran A1/2 and ran B1/2.
Operator Means and the Relative Operator Entropy

Fujii, Jun Ichi

Operator Theory : Adrances and Applications, Birhauser, (59) 161-172, 1992 Peer-reviewed
On Hunmmel’s theorem

Fujii, Jun Ichi, Izumino, Saichi, Nakamura, Masahiro

Mathematica Japonica, 37(5) 985-986, 1992 Peer-reviewed
Norm inequalities related to McIntosh type inequality

Fujii, Jun Ichi, Fujii, Masatoshi, Furuta, Takayuki, Nakamoto, Ritsuo

Nihonkai Juornal of Mathematics, 3(1) 67-72, 1992 Peer-reviewed
Strang’s inequality

Fujii, Jun Ichi, Fujii, Masatoshi, Izumino, Saichi, Kubo, Fumio, Nakamoto,Ritsuo

Math. Japon., 37(3) 479-486, 1992 Peer-reviewed
Graphs and idempotent operators

Fujii, Jun Ichi, Seo, Yuki

Mathematica Japonica, 37(6) 1079-1085, 1992 Peer-reviewed
The spectrum of an infinite directed graph

Fujii, Jun Ichi, Fujii, Masatoshi, Sasaoka, Hiromitsu, Watatani, Yasuo

Mathematica Japonica, 36 36-625, 1991 Peer-reviewed
Graphs and Stampfli’s center of mass

Fujii, Jun Ichi, Seo, Yuki

Mathematica Japonica, 35(5) 855-860, 1990 Peer-reviewed
A norm inequality for operator monotone functions

Fujii, Jun Ichi, Fujii, Masatoshi

Mathematica Japonica, 35(2) 249-252, 1990 Peer-reviewed
Operaor entropy and fuzziness in noncommutative information theory

Fujii, Jun Ichi, Nakamura, Masahiro

Mathematica Japonica, 35, 1990 Peer-reviewed
An extension of the Kubo -Ando theory : Solidarities

Fujii, Jun Ichi, Fujii, Masatoshi, Seo, Yuki

Mathematica Japonica, 35 35-396, 1990 Peer-reviewed
Graphs and the Radjavi-Williams factorization

Fujii, Jun Ichi, Seo, Yuki

Mathematica Japonica, 35(6) 1189-1195, 1990 Peer-reviewed
Convergence of sequence defined by operator means

Fujii, Jun Ichi, Nakamura, Masahiro, Seo, Yuki

Mathematica Japonica, 34(1) 9-14, 1989 Peer-reviewed
Uhlmann's interpolational method for operator means

Fujii, Jun Ichi, Kamei, Eizaburo

Mathematica Japonica, 34 34-547, 1989 Peer-reviewed
Jones'index and the relative operator entropy

Fujii, Jun Ichi, Seo, Yuki

Mathematica Japonica, 34, 1989 Peer-reviewed
Relative operator entropy in noncommutative information theory

Fujii, Jun Ichi, Kamei, Eizaburo

Mathematica Japonica, 34 34-348, 1989 Peer-reviewed
ON OPERATOR INEQUALITIES DUE TO ANDO-KITTANEH-KOSAKI

JI FUJII, M FUJII

PUBLICATIONS OF THE RESEARCH INSTITUTE FOR MATHEMATICAL SCIENCES, 24(2) 295-300, Mar, 1988 Peer-reviewed
数学教育と他教科の関連について地図と面積計の数学

柳本朋子, 藤井淳一, 鈴木正彦, 岡森博和, 小竹仙哉, 阪本善信, 下村成彦

大阪教育大学紀要第V 部門, 37(1) 17-24, 1988
Characterizing the geometric operator mean by the interpolation theory

Fujii, Jun Ichi

Mathematica Japonica, 33(6) 845-849, 1988 Peer-reviewed
On Izumino’s view of operator means

Fujii, Jun Ichi

Mathematica Japonica, 33(5) 671-675, 1988 Peer-reviewed
A parametrization between operator means

Fujii, Jun Ichi, Kubo, Fumio, Kubo Kyoko

Mathematica Japonica, 33(2) 201-208, 1988 Peer-reviewed
スリットカメラと一次変換パソコンと数学による問題の解明II

岡森博和, 藤井淳一, 河辺有希生, 石田香屋子

数学教育研究, 17, 1987
世界地図を作るパソコンと数学による問題の解明I

岡森博和, 藤井淳一, 柳本朋子, 白須賀恒彦, 島和夫

数学教育研究, 17, 1987
The Stein transformation on positive operators

Fujii, Jun Ichi, Nakamoto, Ritsuo

Mathematica Japonica, 32(5) 697-700, 1987 Peer-reviewed

Misc.

負パラメータを持つTsallis relative operator entropy (関数空間の構造とその周辺)

瀬尾祐貴, 藤井淳一

数理解析研究所講究録, (2041) 167-174, Jul, 2017
The adjoint of multi-variable operator means and power ones (作用素論に基づく量子情報理論の幾何学的構造に関する研究と関連する話題)

藤井淳一, 瀬尾祐貴

数理解析研究所講究録, (2033) 115-134, Jun, 2017
RELATIVE OPERATOR ENTROPY AND KARCHER MEAN (Research on structure of operators by order and geometry with related topics)

1996 45-53, Apr, 2016
Relative entropies and information ones for matrices (Theory of operator means and related topics)

Fujii Jun Ichi

RIMS Kokyuroku, 1935 156-162, Apr, 2015
On geometric structure of positive definite matrices (Operator monotone functions and related topics)

Fujii Jun Ichi

RIMS Kokyuroku, 1893 122-125, May, 2014

Books and Other Publications

Operator and Norm Inequalities and Related Topics

Fujii, Jun Ichi, Seo, Yuki (Role: Contributor, Relative Operator Entropy（p.p.69-96）)

Birkhauser, 2022 (ISBN: 9783031021039)
Structural Analysis of Complex Networks

M.Dehmer(ed, F.Emmmert-Streib e (Role: Joint author)

Birkhauser, 2011
Reduced linear codes from cyclic ones

Proceedings of 2005 Symposium on Applied Functional Analysis-Information Sciences and Related Fields, 2007
Jensen's inequalities on any interval for operators

Yokohama PublishersProceedings of the 3rd International Conference on Nonlinear Analysis and Convex Analysis, 2004
Mathematics Education and Personal Computers

(Role: Joint author, Daiichi-Hoki Shuppan)

Daiichi-Hoki Shuppan, 1997

Presentations

Means for fixed rank PSD matrices based on geodesics

Workshop on Operator theory and Operator algebras 2020, Nov 25, 2020
同ランク正半定値の行列平均について

藤井淳一

日本数学会2020 年度春季年会, Mar 18, 2020
同ランク半正定値行列の平均について

藤井淳一

ＲＩＭＳ研究集会「順序を用いた作用素の構造研究と関連する話題」, Oct 24, 2019
ある作用素平均族のべき単調性

藤井淳一

ＲＩＭＳ研究集会「作用素平均を利用した作用素の構造解析の研究と関連する話題」, Oct 25, 2018
power difference mean の表現関数のPM 性について

藤井淳一

日本数学会秋季総合分科会, Sep 25, 2018

Professional Memberships

Research Projects

Geometric structure in quantum information theory based on Operator Theory and its applications

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2019 - Mar, 2022

SEO YUKI
The study on geometrical structure in quantum information theory based on Operator Theory

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2016 - Mar, 2019

Seo Yuki
Opereator inequalities and their application to related fields

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, 2011 - 2013

FUJII Jun Ichi
Developments and Applications for Operator Inequalities

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, 2008 - 2010

FUJII Junichi
非可換エントロピー論

1989

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