Project/Area Number  02302047 
Research Category 
GrantinAid for Cooperative Research (A).

Research Field 
情報工学

Research Institution  Tohoku University 
Principal Investigator 
NISHIZEKI Takao Tohoku University, Faculty of Engineering, Professor, 工学部, 教授 (80005545)

CoInvestigator(Kenkyūbuntansha) 
渡辺 治 東京工業大学, 工学部, 助教授 (80158617)
安浦 寛人 京都大学, 工学部, 助教授 (80135540)
梅尾 博司 大阪電気通信大学, 教授 (80132356)
五十嵐 善英 群馬大学, 工学部, 教授 (60006260)
浅野 孝夫 上智大学, 工学部, 助教授 (90124544)
WATANABE Toshimasa Hiroshima University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (80112184)
HIRATA Tomio Nagoya University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (10144205)
HAGIHARA Kenichi Osaka University, Faculty of Engineering Science, Associate Professor, 基礎工学部, 助教授 (00133140)
KATOH Naoki Kobe University of Commerce, Department of Management Sciecne, Professor, 管理科学科, 教授 (40145826)
IMAI Hiroshi The University of Tokyo, Faculty of Science, Associate Professor, 理学部, 助教授 (80183010)

Project Fiscal Year 
1990 – 1991

Project Status 
Completed(Fiscal Year 1991)

Budget Amount *help 
¥10,800,000 (Direct Cost : ¥10,800,000)
Fiscal Year 1991 : ¥4,800,000 (Direct Cost : ¥4,800,000)
Fiscal Year 1990 : ¥6,000,000 (Direct Cost : ¥6,000,000)

Keywords  Algorithm / Parallel processing / Combinatorial problem / Discrete structure / Computational geometry / Network / Distributed processing / アルゴリズム / 並列処理 / 組合せ問題 / 離散構造 / 計算幾何学 / ネットワク / 分散処理 
Research Abstract 
We studied and examined algorithms which solve problems for discrete structures. We have obtained new knowledge about limitations of current algorithms and algorithm theory. We especially studied parallel and distributed algorithms. We have constructed a base for designing new algorithms, and then, designed and analyzed many new algorithms. The main results are as follows. 1. One of the most important problems in VLSI layout design is a circuit partitioning problem, for which a number of algorithms have been presented. Given a set of modules together with a net list, the problem here is to find an optimal partition of the module set into two so that the areas occupied by modules are comparable in the two sides and the number of interconnections between two sides is minimized. For this problem we compared the method based on graph representation with the one of solving the bipartition problem after mapping modules into points in the plane. 2. For intractable problems such as NPcomplete problems, a lot of algorithms, which are claimed to run fast on average, have been developed. Usually their performances have been estimated by methematical analysis but, especially for practical purposes, it should be also important to estimate them by actually running the algorithms. We discussed how instances of the satisfiability problem, which are to be used to scale the performance of the algorithms, should be generated. We, in turn, showed several instancegeneration algorithms that meet the requirements considered.
