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摘要: In probability theory and statistics, a scale parameter is a special kind of numerical parameter of a parametric family of probability distributions. The larger the scale parameter, the more spread out the distribution.If a family of probability distributions is such that there is a parameter s (and 阅读全文
posted @ 2011-06-26 18:50 emanlee 阅读(1419) 评论(0) 推荐(0) 编辑
摘要: In statistics, a location family is a class of probability distributions parametrized by a scalar- or vector-valued parameter μ, which determines the "location" or shift of the distribution. Formally, this means that the probability density functions or probability mass functions in this c 阅读全文
posted @ 2011-06-26 18:35 emanlee 阅读(754) 评论(0) 推荐(0) 编辑
摘要: In probability theory and statistics, a shape parameter is a kind of numerical parameter of a parametric family of probability distributions. A shape parameter is any parameter of a probability distri... 阅读全文
posted @ 2011-06-26 18:18 emanlee 阅读(2171) 评论(0) 推荐(0) 编辑
摘要: 进行科学的决策是项目评估工作中的主要目的之一。科学的决策方法就是对比判断,亦即对拟建项目的备选方案进行比选。但是,决策存在一定的风险性,项目评估工作中的大量决策基本是属于风险型决策。 概率分析为在风险条件下决定方案取舍的方法,决策树分析也是常用的风险决策方法之一。 所谓决策树分析,就是利用概率分析原理,用树状图描述备选方案的内容、参数、状态以及在实施过程中不同阶段方案的相互关系,对方案进行系统分... 阅读全文
posted @ 2011-06-24 22:43 emanlee 阅读(18008) 评论(0) 推荐(0) 编辑
摘要: Abstract: Tests of fit are given for the generalized Pareto distribution (GPD) based on Cramer-von Mises statistics. Examples are given to illustrate the estimation techniques and the goodness-of-fit ... 阅读全文
posted @ 2011-06-21 07:47 emanlee 阅读(1199) 评论(0) 推荐(0) 编辑
摘要: 可决系数 可决系数(coefficient of determination) 如果样本回归线对样本观测值拟合程度越好,各样本观测点与回归线靠得越近,由样本回归做出解释的离差平方和与总离差平方和越相近;反之,拟合程度越差,相差越大。 可决系数的计算式: 可决系数可以作为综合度量回归模型对样本观测值拟合优度的度量指标。 可决系数是测定多个变量间相关关系密切程度的统计分析指标,它也是反映多个自变量对因... 阅读全文
posted @ 2011-06-20 23:07 emanlee 阅读(10171) 评论(0) 推荐(0) 编辑
摘要: 《极大似然估计的 Bahadur 渐近有效性》,成平, 《数学学报》, 1980年06期 asymptotically efficient estimator 渐近有效估计量 asymptotically normal 渐近正态 asymptotic variance 渐近方差 -- 对数似然函数对估计量的二阶偏导,然后取负号,再对这个数(矩阵)求逆。 阅读全文
posted @ 2011-06-20 22:00 emanlee 阅读(5422) 评论(0) 推荐(0) 编辑
摘要: In probability theory, heavy-tailed distributions are probability distributions whose tails are not exponentially bounded: that is, they have heavier tails than the exponential distribution. In many applications it is the right tail of the distribution that is of interest, but a distribution may hav 阅读全文
posted @ 2011-06-19 20:07 emanlee 阅读(4341) 评论(0) 推荐(1) 编辑
摘要: The goodness of fit of a statistical model describes how well it fits a set of observations. Measures of goodness of fit typically summarize the discrepancy between observed values and the values expe... 阅读全文
posted @ 2011-06-19 15:16 emanlee 阅读(802) 评论(0) 推荐(0) 编辑
摘要: Multiple comparisons In statistics, the multiple comparisons or multiple testing problem occurs when one considers a set of statistical inferences simultaneously. Errors in inference, including confid... 阅读全文
posted @ 2011-06-19 09:31 emanlee 阅读(514) 评论(0) 推荐(0) 编辑
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