Committee 
Date Time 
Place 
Paper Title / Authors 
Abstract 
Paper # 
ET 
20200125 13:25 
Wakayama 
Wakayama JA Building 
Development and Practice of Software to Support Subjects in Lower Grades of Elementary School Tetsuya Shimizu, Koichi Yamazaki (Gunma Univ.) ET201973 
With the spread of information and communication technology (ICT for short), the use of ICT in course instruction has be... [more] 
ET201973 pp.2126 
COMP 
20171027 14:00 
Tokyo 

A Revised Version of "Games with a Single Pile of Stones and Number Theoretic Problems" Yoshihiro Tsukamura (former Sony), Yoshihide Igarashi, Takaaki Fujita, Yuta Urabe, Koichi Yamazaki (Gunma Univ.) COMP201722 
The game MSP(m) discussed in this paper, is played alternately by two players, removing at least one stone and at most $... [more] 
COMP201722 pp.1320 
COMP 
20171027 14:30 
Tokyo 

Linear width and Single ideal Takaaki Fujita, Koichi Yamazaki (Gunma Univ.) COMP201723 
Branchwidth is a well studied graph parameter, and it was extended into parameter on a connectivity system. Linearwidt... [more] 
COMP201723 pp.2127 
COMP 
20160906 13:30 
Toyama 
Toyama Prefectural University 
Games with a Single Pile of Stones and Number Theoretic Problems Yoshihiro Tsukamura (SONY), Yoshihide Igarashi, Yuta Urabe, Koichi Yamazaki (Gunma Univ.) COMP201617 
The game discussed in this paper is played alternately by two players, removing at least one and at most m stones from t... [more] 
COMP201617 pp.1724 
COMP 
20150423 13:40 
Miyagi 

Approximability of width parameters Koichi Yamazaki (Gunma Univ.) COMP20152 
Wu et al. showed that for several graph width parameters including treewidth, pathwidth, and cutwidth, there is no polyn... [more] 
COMP20152 pp.913 
COMP 
20150309 16:30 
Kyoto 
Ritsumeikan University 
Tangle and ideal Koichi Yamazaki (Gunma Univ.) COMP201451 
In this article, we revisit "tangle" defined on a symmetric submodular function of a set $X$ from the viewpoint of idea... [more] 
COMP201451 pp.6164 
COMP 
20140424 10:20 
Miyagi 
Tohoku University 
Thin strip graphs Yota Otachi (JAIST), Akitoshi Kawamura (Univ. of Tokyo), Hidehiro Shinohara (Tohoku Univ.), Takashi Hayashi, Koichi Yamazaki (Gunma Univ.) COMP20141 
A unit disk graph is a emph{$c$strip graph} if it has a unit disk representation in which all centers of the unit disks... [more] 
COMP20141 pp.14 
COMP 
20121031 14:40 
Miyagi 
Tohoku University 
On 1 + $\epsilon$ strip graphs Takashi Hayashi (Gunma Univ.), Hidehiro Shinohara (Tohoku Univ.), Koichi Yamazaki (Gunma Univ.) COMP201239 
A unit disk graph $G$ is called an $\varepsilon$strip graph,
if all center points of the disks lie
in a parallel stri... [more] 
COMP201239 pp.3336 
COMP 
20110309 13:35 
Tokyo 
Chuo Univ. 
Evaluation of metaheuristic algorithms for Spanning Tree Congestion Daiki Maruta (Gunma Univ.), Yota Otachi (Tohoku Univ.), Koichi Yamazaki (Gunma Univ.) COMP201050 
Spanning tree congestion (STC) is a graph parameter
which has been well studied recently.
This work is to compare the... [more] 
COMP201050 pp.2528 
COMP 
20091016 11:10 
Miyagi 
Tohoku University 
Reformulation of the scheme for computing treewidth and minimum fillin Masanobu Furuse, Yota Otachi, Koichi Yamazaki (Gunma Univ.) COMP200934 
Bouchitt´e and Todinca introduced a scheme, i.e., Dynamic Programming based on recursive formulas in terms of minimal se... [more] 
COMP200934 pp.1724 
COMP 
20090417 10:55 
Kyoto 
Kyoto Univ. 
Pathwidth of 3dimensional grids Ryohei Suda, Yota Otachi, Koichi Yamazaki (Gunma Univ.) COMP20093 
The notion of pathwidth of graphs has been introduced by Robertson and Seymour.Pathwidth, which has relations to bandwid... [more] 
COMP20093 pp.1519 
COMP 
20081203 09:30 
Gunma 
Gunma Univ. 
A lower bound for treewidth of Cartesian product graphs Kyohei Kozawa, Yota Otachi, Koichi Yamazaki (Gunma Univ.) COMP200846 
In this paper, we give a lower bound
for treewidth of Cartesian product graphs.
To be more precise,
we show that ... [more] 
COMP200846 pp.15 
COMP 
20081010 15:45 
Miyagi 
Tohoku Univ. 
The carvingwidth of even grids Masanobu Furuse, Kyohei Kozawa, Yota Otachi, Koichi Yamazaki (Gunma Univ.) COMP200843 
In [Call routing and the ratcatcher. Combinatorica 14(2) (1994) 217241],
Seymour and Thomas introduced the concept of... [more] 
COMP200843 pp.7175 
COMP 
20080310 15:55 
Kanagawa 

Security number for outerplanar graphs Kyohei Kozawa, Yota Otachi, Koichi Yamazaki (Gunma Univ.) COMP200764 
Let $G=(V,E)$ be a graph and $S = \{s_1,s_2,\ldots,s_k\}$ be a subset
of $V$.
An \textit{attack} on $S$ is any $k$ m... [more] 
COMP200764 pp.6365 
COMP 
20060322 15:05 
Tokyo 
The University of ElectroCommunications 
Experimental analyses of approximation algorithms for the maximum weighted independent set problem on dclaw free graphs Yota Otachi, Koichi Yamazaki (Gunma Univ.) 
A $d$claw is an induced subgraph isomorphic to $K_{1,d}$. A graph is $d$claw free if it has no $d$claws. Several appr... [more] 
COMP200560 pp.2530 
COMP 
20051222 14:25 
Tokushima 
The University of Tokushima 
Genetic Algorithms for bandwidth reduction problem Kazumasa Aoki, Yota Otachi, Koichi Yamazaki (Gunma Univ.) 
(To be available after the conference date) [more] 
COMP200553 pp.2936 
COMP 
20050318 14:35 
Tokyo 
Tokyo Institute of Technology 
A lower bound for the vertex isoperimetric number of the complete kary tree Yota Otachi, Kaori Umezawa, Koichi Yamazaki (Gunma Univ.) 
The vertex isoperimetric number problem (for short VINP) is to determine the value of vi(G)= max_{1 \le k \le V} min_{... [more] 
COMP200480 pp.5760 
COMP 
20041210 14:30 
Chiba 
Toho University 
Interval bigraphs are unit grid intersection graphs Yota Otachi, Koichi Yamazaki (Gunma Univ.) 
An interval bigraph is the intersection graph of two families of intervals on the real line such that vertices are adjac... [more] 
COMP200456 pp.2123 