• Title/Summary/Keyword: 단계별추출추정법

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Comparison of Step-Wise and Exact Maximum Likelihood Estimations on Cell Probabilities of Contingency Table (단계별로 얻어진 이차원 분할표의 모수 추정을 위한 정확최대우도추정법과 단계별추출추정법의 비교)

  • Lee, Sang-Eun;Kang, Kee-Hoon;Jeung, Seok-O;Shin, Key-Il
    • Communications for Statistical Applications and Methods
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    • v.17 no.1
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    • pp.67-77
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    • 2010
  • In multinomial scheme with step-wise sampling, maximum likelihood estimates of multinomial probabilities are improved when some frequencies are merged. In this study, for cell probabilities in a I by J independent contingency tables, exact MLE and step-wise estimation methods are applied and the results are compared using MSE and Bias.

Stochastic Simulation Model of Fire Occurrence in the Republic of Korea (한국 산불 발생에 대한 확률 시뮬레이션 모델 개발)

  • Lee, Byungdoo;Lee, Yohan;Lee, Myung Bo;Albers, Heidi J.
    • Journal of Korean Society of Forest Science
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    • v.100 no.1
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    • pp.70-78
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    • 2011
  • In this study, we develop a fire stochastic simulation model by season based on the historical fire data in Korea. The model is utilized to generate sequences of fire events that are consistent with Korean fire history. We employ a three-stage approach. First, a random draw from a Bernoulli distribution is used to determine if any fire occurs for each day of a simulated fire season. Second, if a fire does occur, a random draw from a geometric multiplicity distribution determines their number. Last, ignition times for each fire are randomly drawn from a Poisson distribution. This specific distributional forms are chosen after analysis of Korean historical fire data. Maximum Likelihood Estimation (MLE) is used to estimate the primary parameters of the stochastic models. Fire sequences generated with the model appear to follow historical patterns with respect to diurnal distribution and total number of fires per year. We expect that the results of this study will assist a fire manager for planning fire suppression policies and suppression resource allocations.