| Project/Area Number |
09680442
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Natural disaster science
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| Research Institution | Toyama Univ. |
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Principal Investigator |
MURAI Tadakuni Toyama Univ. Prof., 工学部, 教授 (40019196)
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| Co-Investigator(Kenkyū-buntansha) |
HORITA Yuukou Toyama Univ. Associate Prof., 工学部, 助教授 (80209303)
KAWAI Takeo Hokuriku Elec. Co. Head of section, 地域総合研究所, 部長
池田 長康 富山大学, 工学部, 教授 (10222895)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | thundercloud / electric field / boundary element / charge distribution / lightning forecast / estimation algorithm / 雷雲電荷 / 逆問題 / 数値落雷予測 |
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| Research Abstract |
The information of the electric field intensity on the ground is useful for forecasting the lightning. To investigate the capability of the proposed approaches for estimating the electric charge distribution in thundercloud from the electric field information, the following studies were carried out.
First, a new boundary element technique named semi-infinit boundary element was proposed to calculate the electric field caused by the electric charge in cloud. It is found that the electric field distribution considering the effect of the topography can easily be evaluated by using the technique.
Second, to estimate the electric charge distribution from the electric field measured on the ground surface, some algorithms such as Newton scheme, Least square's method, Sampled pattern matching method, Neural network and Kalman filter were investigated. In the electric charge estimation problem, the number of the measuring points may be so small that a special device must be introduced to increase the "virtual measuring point". It is found from the numerical simulation that Newton scheme would be most suitable for accurate estimation, and also the electric field intensity data must be measured with three significant digit figures for the estimation.
As another study, a weather-proof type equipment using potentiometer was developed to measure the electric field on the ground. However, the quality of the measurement accuracy must be improved for practical use.
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