| Project/Area Number |
15360006
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Nagoya University |
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Principal Investigator |
SAKATA Makoto Nagoya University, Faculty of Engineering, Department of Applied Physics, Professor, 大学院・工学研究科, 教授 (40135306)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIBORI Eiji Nagoya University, Faculty of Engineering, Department of Applied Physics, Associate Professor, 大学院・工学研究科, 助教授 (10293672)
AOYAGI Shinobu Nagoya University, Faculty of Engineering, Department of Applied Physics, Research Associate, 大学院・工学研究科, 助手 (40360838)
TAKATA Masaki Japan Synchrotron Radiation Research Institute, Research and Utilization Division, Director, 利用研究促進部門I, 主席研究員 (60197100)
KUBOTA Yoshiki Osaka prefecture university, Department of Physics, Lecturer, 理学系研究科, 講師 (50254371)
KATO Kenichi Japan Synchrotron Radiation Research Institute, Research and Utilization Division, Researcher, 利用研究促進部門I, 研究員 (90344390)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2005: ¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 2004: ¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 2003: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Genetic Algorithm / Schema / adaptive solution / Powder Structural Analysis / Maximum Entropy Method / Difference MEM / Ab initio Analysis / Charge Density / 遺伝的アルゴリズム(GA) / 並列計算機 / X線回折 / 格子定数決定 / 構造決定 / 放射光X線 / 20自由度 / 電荷移動錯体 / 粉末X線構造解析 / マキシマムエントロピー法 / 単一分子からなる分子性金属 / 金属内包フラーレン / ab-initio構造決定 / 分子動力学計算 |
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| Research Abstract |
Genetic algorithm (GA) is used in search and optimization of many parameters in genotype, such as finding the maximum of a function over some domain space. GA is inspired by John Holland's theory for adaptation. In GA optimization, the schema theorems provide probabilistic solutions, which is appropriate for adaptation.
In an X-ray structural analysis, probabilistic solutions have basically no usefulness. We have to determine an optimum solution in the present study rather than probabilistic solutions. Thus, probabilistic solutions must progress to the optimum solution. At first, we expected that the Maximum Entropy Method (MEM) show abilities in the evolution from probabilistic to optimum solution, which is very difficult process. In the present research, it is found that difference-MEM (DMEM) has great abilities for such process.
The DMEM is useful for various situations of analysis process. The two main processes are described as follows. One is the DMEM charge density based on full structure model. The other is the DMEM charge density based on a structure model, in which a few atoms are intentionally omitted. In both cases, the DMEM charge density is much more useful than the ordinary MEM charge density for the present purposes. The reason is very clear. The DMEM can easily reveal the weak charge density. The utilization of DMEM with the combination of GA would be the main achievement of present study. It provides the possibilities for precise structural analysis of the larger molecular materials, such as pharmaceutical compounds.
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