An empirical Bayes（EB）two-sided test problem about the continuousone-parameter exponential family has been discussed.We construct the EB test decisionrule and prove its asymptotical optimality.Further,we get its con...An empirical Bayes（EB）two-sided test problem about the continuousone-parameter exponential family has been discussed.We construct the EB test decisionrule and prove its asymptotical optimality.Further,we get its convergence ratesO(n<sup>-（λ（s-2））/（2s+1）</sup>under suitable conditions,where 0【λ【2,and s】2 is a given natural number.Finally,some examples about the result of the convergence rates are given.展开更多
Heterosis represents one of the most revolutionary advancements in crop improvement.In the genetic dissection of heterosis,NCIII design is one of the most powerful and widely used mating schemes.However,the methodolog...Heterosis represents one of the most revolutionary advancements in crop improvement.In the genetic dissection of heterosis,NCIII design is one of the most powerful and widely used mating schemes.However,the methodologies for quantitative trait loci (QTL) detection in the design were mostly based on composite interval mapping.Therefore,in this study,our purpose was to develop a statistical method for mapping epistatic QTL associated with heterosis in the RIL-based NCIII design.First,we derivated the expectations of two classical linear transformations,Z 1 and Z 2,while a quantitative trait was controlled by two QTL with digenic epistasis and arbitrary linkage under the F ∞ and F 2 metric models.Then,we constructed an epistatic genetic model that includes all markers on the whole genome simultaneously,and estimated all the parameters in the model by the empirical Bayes approach.Finally,a series of Monte Carlo simulation experiments was carried out to confirm the proposed approach.The results show that:(1) all the augmented genetic parameters for main-effect QTL could be rightly identified with satisfactory statistical power and precision;(2) the statistical powers in the detection of augmented epistatic effects were substantively affected by the signs of pure epistatic effects;(3) it is more difficult to detect epistatic QTL than to detect main-effect QTL;(4) statistical power is higher in the RIL-based NCIII design than in the F 2-based NCIII design,especially in the detection of the augmented epistatic effect that consists of two pure epistatic effects in opposite directions.展开更多
This paper considers the empirical Bayes （EB） estimation problem for the parameter β of the linear regression model y = Xβ＋ ε with ε- N（0, σ^2I） given β. Based on Pitman closeness （PC） criterion and mean ...This paper considers the empirical Bayes （EB） estimation problem for the parameter β of the linear regression model y = Xβ＋ ε with ε- N（0, σ^2I） given β. Based on Pitman closeness （PC） criterion and mean square error matrix （MSEM） criterion, we prove the superiority of the EB estimator over the ordinary least square estimator （OLSE）.展开更多
In urban or suburban areas with a large number of access points, four-lane undivided highways are prone to crashes due to left-turning and through movements in a single lane. Many studies recommended expensive counter...In urban or suburban areas with a large number of access points, four-lane undivided highways are prone to crashes due to left-turning and through movements in a single lane. Many studies recommended expensive countermeasures like conversion from undivided to divided road with physical separation. One inexpensive alternative is reconfiguring the existing roadways by either increasing or decreasing the number of lanes. This study investigated the safety impact of converting four lane undivided roadways （4U） to five lane undivided roadways （ST） with a two way left turn lane （TIkrLTL）. This study used Empirical Bayes method to determine the safety impact of this inexpensive countermeasure. In this study, data from eight sites from Louisiana were collected for investigation, and site- specific crash modification factor （CMF） values were calculated. Although ST is usually not preferable due to its exposure of higher number of crashes in the existing literature, the findings of the current study indicated a positive safety impact. The benefit-cost ratio of this conversion ranges from 97 to 379. The current findings indicate that conversion of 4U to 5T is a feasible inexpensive solution for urban roadways with lower volume and a limited number of driveways.展开更多
For the data with error of measurement in historical samples, the empirical Bayes test rule for the parameter of Rayleigh distribution is constructed, and the asymptotically optimal property is obtained. It is shown t...For the data with error of measurement in historical samples, the empirical Bayes test rule for the parameter of Rayleigh distribution is constructed, and the asymptotically optimal property is obtained. It is shown that the convergence rate of the proposed EB test rule can be arbitrarily close to O（n-1/2） under suitable conditions.展开更多
基金project supported by National Natural Science Foundation of China
文摘An empirical Bayes（EB）two-sided test problem about the continuousone-parameter exponential family has been discussed.We construct the EB test decisionrule and prove its asymptotical optimality.Further,we get its convergence ratesO(n<sup>-（λ（s-2））/（2s+1）</sup>under suitable conditions,where 0【λ【2,and s】2 is a given natural number.Finally,some examples about the result of the convergence rates are given.
基金supported by the National Basic Research Program of China(2011CB109306)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions+1 种基金the National Natural Science Foundation of China(30900842,31000666)the NAU Youth Sci-Tech Innovation Fund(KJ08001)
文摘Heterosis represents one of the most revolutionary advancements in crop improvement.In the genetic dissection of heterosis,NCIII design is one of the most powerful and widely used mating schemes.However,the methodologies for quantitative trait loci (QTL) detection in the design were mostly based on composite interval mapping.Therefore,in this study,our purpose was to develop a statistical method for mapping epistatic QTL associated with heterosis in the RIL-based NCIII design.First,we derivated the expectations of two classical linear transformations,Z 1 and Z 2,while a quantitative trait was controlled by two QTL with digenic epistasis and arbitrary linkage under the F ∞ and F 2 metric models.Then,we constructed an epistatic genetic model that includes all markers on the whole genome simultaneously,and estimated all the parameters in the model by the empirical Bayes approach.Finally,a series of Monte Carlo simulation experiments was carried out to confirm the proposed approach.The results show that:(1) all the augmented genetic parameters for main-effect QTL could be rightly identified with satisfactory statistical power and precision;(2) the statistical powers in the detection of augmented epistatic effects were substantively affected by the signs of pure epistatic effects;(3) it is more difficult to detect epistatic QTL than to detect main-effect QTL;(4) statistical power is higher in the RIL-based NCIII design than in the F 2-based NCIII design,especially in the detection of the augmented epistatic effect that consists of two pure epistatic effects in opposite directions.
文摘This paper considers the empirical Bayes （EB） estimation problem for the parameter β of the linear regression model y = Xβ＋ ε with ε- N（0, σ^2I） given β. Based on Pitman closeness （PC） criterion and mean square error matrix （MSEM） criterion, we prove the superiority of the EB estimator over the ordinary least square estimator （OLSE）.
基金Louisiana Transportation Research Center (LTRC Project No. 08-3SS) for their support
文摘In urban or suburban areas with a large number of access points, four-lane undivided highways are prone to crashes due to left-turning and through movements in a single lane. Many studies recommended expensive countermeasures like conversion from undivided to divided road with physical separation. One inexpensive alternative is reconfiguring the existing roadways by either increasing or decreasing the number of lanes. This study investigated the safety impact of converting four lane undivided roadways （4U） to five lane undivided roadways （ST） with a two way left turn lane （TIkrLTL）. This study used Empirical Bayes method to determine the safety impact of this inexpensive countermeasure. In this study, data from eight sites from Louisiana were collected for investigation, and site- specific crash modification factor （CMF） values were calculated. Although ST is usually not preferable due to its exposure of higher number of crashes in the existing literature, the findings of the current study indicated a positive safety impact. The benefit-cost ratio of this conversion ranges from 97 to 379. The current findings indicate that conversion of 4U to 5T is a feasible inexpensive solution for urban roadways with lower volume and a limited number of driveways.
基金The NSF(1012138,0612163)of Guangdong Ocean Unversitythe Scientific and Technological Project(2010C3112006)of Zhanjiang
文摘For the data with error of measurement in historical samples, the empirical Bayes test rule for the parameter of Rayleigh distribution is constructed, and the asymptotically optimal property is obtained. It is shown that the convergence rate of the proposed EB test rule can be arbitrarily close to O（n-1/2） under suitable conditions.
