| Project/Area Number |
08680328
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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 |
Statistical science
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| Research Institution | Tokyo University of Fisheries |
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Principal Investigator |
YAMADA Sakutaro Tokyo University of Fisheries, Department of Fisheries, Professor, 水産学部, 教授 (60017077)
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| Co-Investigator(Kenkyū-buntansha) |
KITAKADO Toshihide Tokyo University of Fisheries, Department of Fisheries, Assistant Professor, 水産学部, 助手 (40281000)
TANAKA Eiji Tokyo University of Fisheries, Department of Fisheries, Associate Professor, 水産学部, 助教授 (40217013)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
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| Keywords | Age Determination / Length-Age Transformation / Incomplete Data / EM Algorithm / Information / 推定精度 |
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| Research Abstract |
We show our main results obtained by this project.
1. Iterated age-length transformation kernel method.
This method is done using EM-algorithm, which is nowadays popular in statistics to estimate unknown parameters of the complete data distribution using the observed incomplete data. We found the EM-algorithm assumes that the mechanism of the data incompleteness was known. This fault is important in application of fishery resource analysis, and is difficult to be resolved.
2. Log-linear model.
In this model the notion of the age-length transformation kernel is not used. But, as is with the above-mentioned kernel method, in this model the data of the length composition are obtained through the selection of the fishing net mesh size. Hence the data do not reflect true length distribution. We already have an idea for this problem, but is not solved completely.
3. These are our main results obtained. We furthermore will continue studying this important problem in fishery resource analysis
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