Department of Mathematics

Researcher List >> Yoshiyuki Ohyama
 

Yoshiyuki Ohyama

 
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NameYoshiyuki Ohyama
URL
AffiliationTokyo Woman's Christian University
SectionSchool of Arts and Sciences
Job titleProfessor
DegreeDocter of Science(Waseda University), 理学修士(早稲田大学)
J-Global ID200901010817271379

Research Interests

 
結び目理論 ,Knot Theory

Research Areas

 
  • Natural sciences / Geometry / 

Education

 
 
 - 
1990
Waseda University  
 
 
 - 
1990
Waseda University Graduate School, Division of Science and Engineering 
 
 
 - 
1985
Waseda University School of Science and Engineering 
 
 
 - 
1985
Waseda University Faculty of Science and Engineering 
 

Papers

 
 
Yoshiyuki Ohyama   Migiwa Sakurai   
46(1) 19-31   Jun 2023   [Refereed]
 
Yoshiyuki OHYAMA   Migiwa SAKURAI   
Journal of the Mathematical Society of Japan   73(3)    Jul 2021   [Refereed]
 
Yoshiyuki Ohyama   Migiwa Sakurai   
Journal of Knot Theory and Its Ramifications   28(12) 1950074-1950074   Oct 2019   [Refereed]
Satoh and Taniguchi introduced the [Formula: see text]-writhe [Formula: see text] for each non-zero integer [Formula: see text], which is an invariant for virtual knots. The [Formula: see text]-writhes give the coefficients of some polynomial inva...
 
Sumiko Horiuchi   Yoshiyuki Ohyama   
JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS   26(13)    Nov 2017   [Refereed]
We consider a local move, denoted by., on knot diagrams or virtual knot diagrams. If two (virtual) knots K-1 and K-2 are transformed into each other by a finite sequence of lambda moves, the lambda distance between K-1 and K-2 is the minimum numbe...
 
Sumiko Horiuchi   Yoshiyuki Ohyama   
JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS   23(4)    Apr 2014   [Refereed]
A local move called a C-n-move is closely related to Vassiliev invariants. The C-n-distance between two knots K and L, denoted by d(Cn) (K, L), is the minimal number of C-n-moves needed to transform K into L. In the case of n >= 3, we show that...

Misc.

 
 
Sumiko Horiuchi   Yoshiyuki Ohyama   
JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS   19(4) 503-507   Apr 2010   
Adams et al. introduce the notion of almost alternating links; non-alternating links which have a projection whose one crossing change yields an alternating projection. For an alternating knot K, we consider the number Alm(K) of almost alternating...
 
Sumiko Horiuchi   Yoshiyuki Ohyama   
JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS   19(4) 503-507   Apr 2010   
Adams et al. introduce the notion of almost alternating links; non-alternating links which have a projection whose one crossing change yields an alternating projection. For an alternating knot K, we consider the number Alm(K) of almost alternating...
 
Yasutaka Nakanishi   Yoshiyuki Ohyama   
HIROSHIMA MATHEMATICAL JOURNAL   39(3) 443-450   Nov 2009   
After the works of Kauffman-Banchoff and Yamasaki, it is known that a local move called the pass move is strongly related to the Arf invariant, which is equivalent to the parity of the coefficient of the degree two term in the Conway polynomial. O...
 
Yasutaka Nakanishi   Yoshiyuki Ohyama   
Hiroshima Mathematical Journal   39(3) 443-450   2009   
 
Yoshiyuki Ohyama   Harumi Yamada   
JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS   17(7) 771-785   Jul 2008   
It is shown that two knots can be transformed into each other by C-n-moves if and only if they have the same Vassiliev invariants of order less than n. Consequently, a C-n-move cannot change the Vassiliev invariants of order less than n and may ch...

Books and Other Publications

 
 
 
培風館   1995      

Professional Memberships

 
 
   
 
日本数学会
 
   
 
Mathematical Society of Japan

Research Projects

 
 
A study of invariants and local moves for virtual knots
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research
Project Year: Apr 2021 - Mar 2025
 
結び目と3次元多様体の量子トポロジー
日本学術振興会: 科学研究費助成事業
大槻 知忠 金信 泰造 伊藤 哲也 谷山 公規 藤原 耕二 逆井 卓也 大山 淑之 山下 靖 茂手木 公彦 森藤 孝之 玉木 大 志摩 亜希子 
Project Year: Apr 2016 - Mar 2021
 
Geometric structures and combinaorial structures of 3-manifolds
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research
Sakuma Makoto 
Project Year: Apr 2015 - Mar 2020
 
Topology of knots and 3-manifolds
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research
Ohtsuki Tomotada KAMADA Seiichi HABIRO Kazuo 
Project Year: Apr 2012 - Mar 2017
 
Studies of knot theory and their applications
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research
KAWAUCHI Akio KAMADA Seiichi SAKUMA Makoto NAKANISHI Yasutaka TANIYAMA Kouki OOYAMA Toshiyuki MOTEGI Kimihiko GOUDA Hiroshi SHIMOKAWA Koya TERAGAITO Masakazu SATOU Shin TANAKA Toshihumi IWAKIRI Masahide CHON Inde KISHIMOTO Kengo OTSUKI Tomotada SHIMIZU Ayaka 
Project Year: Apr 2012 - Mar 2017

Social Activities

 
 
[Advisor,Report writing]
 1 Apr 2022 - 31 Mar 2023