OKUMURA Hiroshi

J-GLOBAL         Last updated: Dec 9, 2017 at 11:22
 
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Name
OKUMURA Hiroshi
E-mail
hokmrprotonmail.com

Published Papers

 
Haga's theorems in paper folding and related theorems in Wasan geometry Part 1
OKUMURA Hiroshi
arxiv.org   1-14   Nov 2017
Wasan geometry with the division by 0
OKUMURA Hiroshi
arxiv.org   1-4   Nov 2017
The Descartes circles theorem and division by zero calculus
OKUMURA Hiroshi, Saitoh Saburou
arxiv.org   1-9   Nov 2017
A note on the problems involving congruent circles in Tenzan Kaitei
OKUMURA Hiroshi
Sangaku Journal of Mathematics   1 39-41   Nov 2017   [Refereed]
A SURVEY OF MATHEMATICS DISCOVERED BY COMPUTERS. PART 2.
Sava Grozdev, Hiroshi Okumura, Deko Dekov
Mathematics and Informatics   60(6) 543-550   Dec 2017   [Refereed]
Theorems on two congruent circles on a line
OKUMURA Hiroshi
Sangaku Journal of Mathematics   1 35-38   Oct 2017   [Refereed]
Configurations of congruent circles on a line
OKUMURA Hiroshi
Sangaku Journal of Mathematics   1 24-34   Oct 2017   [Refereed]
Computer Discovered Mathematics: Problems for Students about Excentral Triangle
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 185-200   Oct 2017   [Refereed]
Problems on the Brocard circle
Save Grozdev, Hiroshi Okumura, Deko Dekov
Mathematics and Informatics   60(4) 382-390   Aug 2017   [Refereed]
Computer Discovered Mathematics: Notable Circles
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 117-134   Jun 2017   [Refereed]
Leversha Triangles and Leversha Points
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 111-116   Jun 2017   [Refereed]
Computer Discovered Mathematics: Triangles Associated with Triangulation Triangles
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 106-110   Jun 2017   [Refereed]
Triangles Homothetic with Triangle ABC. Part 3
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 97-105   Jun 2017   [Refereed]
Triangles Homothetic with Triangle ABC. Part 2
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 90-96   May 2017   [Refereed]
Triangles Homothetic with Triangle ABC
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2 86-89   Apr 2017   [Refereed]
Poristic triangles of the arbelos
Antonio Gutierrez, Hiroshi Okumura, Hussein Tahir
International Journal of Geometry   6(1) 27-35   Apr 2017   [Refereed]
Computer Discovered Mathematics: Problems about Points on the Euler line
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 81-85   Mar 2017   [Refereed]
Computer Discovered Mathematics: Excenters-Incenter Reflections Triangle
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 72-80   Mar 2017   [Refereed]
Relations of 0 and infinity
Hiroshi Okumura, Saburou Saitoh, Tsutomu Matsuura
Journal of Technology and Social Science   1(1) 70-77   Mar 2017   [Refereed]
A three tangent congruent circle problem
Yasuo Kanai, Hiroshi Okumura
Sangaku Journal of Mathematics   1 16-20   Mar 2017   [Refereed]
Computer Discovered Mathematics: Half-Anticevian Triangle of the Incenter
Sava Grozdev, Hiroshi Okumura, Deko Dekov,
International Journal of Computer Discovered Mathematics   2(1) 55-71   Feb 2017   [Refereed]
Computer Discovered Mathematics: Triangles homothetic with the Orthic triangle
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 46-54   Feb 2017   [Refereed]
Computer Discovered Mathematics: Incentral Triangle
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 35-45   Feb 2017   [Refereed]
A Note on the Leversha Point
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 30-34   Jan 2017   [Refereed]
Japanese mathematics
OKUMURA Hiroshi
Sangaku Journal of Mathematics   1 1-6   Jan 2017   [Refereed]
Division by Zero z/0 = 0 in Euclidean Spaces
Hiroshi Michiwaki, Hiroshi Okumura, Saburoh Saitoh
International Journal of Mathematics and Computation   28(1) 1-16   Jan 2017   [Refereed]
Computer Discovered Mathematics: Euler Anticevian Triangles
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   2(1) 1-29   Jan 2017   [Refereed]
A Characterization of the Golden Arbelos
OKUMURA Hiroshi
Mathematical Medley   42(2) 3-5   Dec 2016   [Refereed]
Computer Discovered Mathematics: Grebe Triangles
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   1(4) 14-23   Nov 2016   [Refereed]
Computer Discovered Mathematics: Haimov Triangle of the Incenter
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   1(3) 57-61   Oct 2016   [Refereed]
Computer Discovered Mathematics: Orthopoles
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   1(3) 50-56   Oct 2016   [Refereed]
An equilateral triangle in the arbelos
OKUMURA Hiroshi
International Journal of Geometry   5(2) 93-95   Oct 2016   [Refereed]
Computer Discovered Mathematics: A Note on the Miquel Points
Sava Grozdev, Hiroshi Okumura, Deko Dekov
International Journal of Computer Discovered Mathematics   1(3) 45-49   Sep 2016   [Refereed]
Origamics with Wasan geometry
OKUMURA Hiroshi
Symmetry: Culture and Science   28(3) 312-320   Jul 2016   [Refereed]
A note on regular pentagons arising from the golden arbelos
OKUMURA Hiroshi
Global Journal of Advanced Research on Classical and Modern Geometries   5(2) 75-77   Oct 2016   [Refereed]
The square of the arbelos
OKUMURA Hiroshi
Global Journal of Advanced Research on Classical and Modern Geometries   5(1) 46-55   Apr 2016   [Refereed]
Two Pairs of Archimedean Circles Derived from a Square
OKUMURA Hiroshi
Forum Geometricorum   16 23-24   Mar 2016   [Refereed]
An inscribed square of a right triangle associated with an arbelos
Hiroshi Okumura
Global Journal of Advanced Research on Classical and Modern Geometries   4(2) 125-135   Oct 2015   [Refereed]
The inscribed square of the arbelos
OKUMURA Hiroshi
Global Journal of Advanced Research on Classical and Modern Geometries   4(1) 55-61   Apr 2015   [Refereed]
Archimedean circles passing through a special point
OKUMURA Hiroshi
International Journal of Goemetry   4(1) 5-10   Apr 2015   [Refereed]
The arbelos with overhang
OKUMURA Hiroshi
KoG   18 19-27   Dec 2014   [Refereed]
A Folded Square Sangaku Problem
Hiroshi Okumura
Mathematical Medley   40(2) 21-23   Dec 2014   [Refereed]
Archimedean circles related to the Schoch line
Hiroshi Okumura
Forum Geometricorum   14 369-370   Nov 2014   [Refereed]
A note on Haga's theorems in paper folding
Hiroshi Okumura
Forum Geometricorum   14 241-242   Sep 2014   [Refereed]
Lamoenian Circles of the Collinear Arbelos
Hiroshi Okumura
KoG   17 9-13   Dec 2013   [Refereed]
Archimedean twin circles in the arbelos
Hiroshi Okumura
Mathematical Gazette   97(540) 512-512   Nov 2013   [Refereed]
Archimedean circles of the collinear arbelos and the skewed arbelos
Hiroshi Okumura
Journal for Geometry and Graphics   17(1) 31-52   Jul 2013   [Refereed]
The area of a generalised arbelos
Hiroshi Okumura
Mathematical Gazette   97(538) 157-160   Mar 2013   [Refereed]
Ubiquitous Archimedean circles
Hiroshi Okumura
Mathematics and Informatics   55(4) 308-311   2012   [Refereed]
Archimedean Circles Induced by Skewed Arbeloi
NAKAJIMA Ryuichi, OKUMURA Hiroshi
Journal for Geometry and Graphics   16 13-17   2012   [Refereed]
Dilations and the arbelos
Hiroshi Okumura
Normat   60(1) 4-8   2012   [Refereed]
Ubiquitous Archimedean Circles of the Collinear Arbelos
Hiroshi Okumura
KoG   16 17-20   Dec 2012   [Refereed]
Are those Archimedean triplet circles really triplets?
Hiroshi Okumura
Normat   60(1) 9-14   2012   [Refereed]
More on Twin Circles of the Skewed Arbelos
Hiroshi Okumura
Forum Geometricorum   11 139-144   2011   [Refereed]
Generalized arbelos in aliquot parts: non-intersecting case
Hiroshi Okumura and Masayuki Watanabe
Journal for Geometry and Graphics   13 41-57   2009   [Refereed]
Generalized arbelos in aliquot parts: intersecting case
Hiroshi Okumura and Masayuki Watanabe
Journal for Geometry and Graphics   12 53-62   2008   [Refereed]
Characterizations of an infinite set of Archimedean circles
Hiroshi Okumura and Masayuki Watanabe
Forum Geometricorum   7 121-123   2007   [Refereed]
Remarks on Woo's Archimedean circles
Hiroshi Okumura and Masayuki Watanabe
Forum Geometricorum   7 125-128   2007   [Refereed]
The arbelos, mathematics and computer graphics
Hiroshi Okumura and Masayuki Watanabe
Proceedings of the twelfth Asian technology conference in mathematics   20-30   2007   [Refereed]
A generalization of Power's Archimedean circles
Hiroshi Okumura and Masayuki Watanabe
Forum Geometricorum   6 103-105   2006   [Refereed]
Non-Archimedean twin circles in the arbelos
Hiroshi Okumura and Masayuki Watanabe
Mathematics Plus   13(1) 60-62   2005
The arbelos in n-aliquot parts
Hiroshi Okumura and Masayuki Watanabe
Forum Geometricorum   5 37-45   2005   [Refereed]
The twin circles of Archimedes in a skewed arbelos
Hiroshi Okumura and Masayuki Watanabe
Forum Geometricorum   4 229-251   2004   [Refereed]
Japanese Mathematics
Hiroshi Okumura
Symmetry: Culture and Science   12(1-2) 79-86   2001
Tangent Circles in the ratio 2:1
Hiroshi Okumura and Masayuki Watanabe
Crux Mathematicorum   27(2) 116-120   2001   [Refereed]
A self-similar circle pattern
Eiji Nakajima, Ryuichi Nakajima, Hiroshi Okumura
Mathematics and Informatics Quarterly   10(2) 79-81   2000
A double tiling of triangles and regular hexagons
Hiroshi Okumura, John Rigby
Discrete and Computational Geometry   24(2-3 467-479)    2000   [Refereed]
Geometries in the East and the West in the 19th century
Hiroshi Okumura
Symmetry: Culture and Science   10(1-2) 189-197   1999
Generalisations of a four-square theorem
Hiroshi Okumura, John Rigby
25(1) 20-24   1999   [Refereed]
Ebisui's theorem and a (15_4, 20_3) configuration
Hiroshi Okumura
Journal of Graphic Science of Japan   32(4) 23-28   1998   [Refereed]
A surprising property of successively touching circles
Hiroshi Okumura, Chuichi Sodeyama
Mathematics Plus   6(3) 17-18   1998
Incircles of rhombuses
Hiroshi Okumura, Eiji Nakajima
Mathematics and Informatics Quarterly   8(3) 143-148   1998
A high speed ray tracing algorithm using similarity of neighboring image pixels
Proceeding of International Symposium on Information theory and its Applications Mexico City   553-556   1998
Problems involving right triangles with tangent circles
Hiroshi Okumura
Mathematics and Informations Quarterly   8(1) 34-36   1998
Sangaku problems involving a rectangle divided into three triangles with tangent circles
Hiroshi Okumura
Mathematics and Informatics Quarterly   7(2) 89-92   1997

Misc

 
Hiroshi Okumura
Sangaku Journal of Mathematics   1 11-12   Feb 2017   [Refereed]
We propose two problems arising from figures appeared in sangaku problems in Fukushima.
課題76-3の一般化
OKUMURA Hiroshi
初等数学(初等数学の会)   (80) 24-25   Jan 2017
A note on the problem 73-2
OKUMURA Hiroshi
Shotoh Sugaku   78(3) 40-41   Mar 2016
Origamics involving circles
OKUMURA Hiroshi
37-42   Feb 2016
Problem 158
Save Grozdev, Hiroshi Okumura, Deko Dekov
MathProblems Journal   6(2) 560-560   2016
Rendering Algorithm of a Motion Blur Image Using Adaptive Distributed Ray Tracing : A High Speed Image Signal Processing for Three Dimensional Computer Graphics
NIINO Takahiro, OKUMURA Hiroshi, Sodeyama Chuich
Bulletin of Maebashi Institute of TechnologyB   4 89-90   Mar 2001
The Separation of Polyphonic Tone of Different Class of Two Musical Instruments
Minoru TODA, Hiroshi OKUMURA, Chuichi Sodeyama
3 97-102   Mar 2000
Mathematical study of Wasan geometry
OKUMURA Hiroshi
Proceedings of Fourth international symposium on the history of mathematics using Chinese characters   129-139   1999

Books etc

 
Origami^3
OKUMURA Hiroshi
A K Peters   Jul 2002   
The Pattern Book: Fractals, Art, and Nature
OKUMURA Hiroshi
World Scientific   Jul 1995   

Conference Activities & Talks

 
Twin circles in a triangle and its application to an arbelos
Hiroshi Okumura and Masayuki Watanabe
International Conference "Synergetics and reflection in mathematics education", At Bachinovo, Bulgaria   10 Sep 2010   

Social Contribution

 
Mathematical Reviews reviewer
[Report writing]
Zentralblatt MATH reviewer
[Report writing]
International Journal of Computer Discovered Mathematics, editor in chief
[Chief Editor, Editor, Planner]
Sangaku Journal of Mathematics, editor-in-chief
[Chief Editor, Editor, Planner]