An improved averaged two-replication procedure with Latin hypercube sampling

The averaged two-replication procedure assesses the quality of a candidate solution to a stochastic program by forming point and confidence interval estimators on its optimality gap. We present an improved averaged two-replication procedure that uses Latin hypercube sampling to form confidence intervals of optimality gap. This new procedure produces tighter and less variable interval widths by reducing the sampling error by $\sqrt{2}$. Despite having tighter intervals, it improves an earlier procedure’s asymptotic coverage probability bound from ${(1?\alpha )}^2$ to $(1?\alpha )$.     

长沙市规模以下零售业抽样调查方案

本文介绍了一个根据具体城市情况制定的零售贸易餐饮业的抽样调查方案.以长沙市规模以下零售业、餐饮业为总体,用区域抽样代替一般的名录抽样,并采用细致的分层解决商业单位分布不均匀问题.文中也给出了与抽样方案配套的总体和域目标量的估计及相应的方差估计公式.     

两个方差分量的不变二次估计的可容许性

本文对Ｙ￣Ｎ（Ｘβ，θ１Ｖ１＋θ２Ｖ２），Ｖ１，Ｖ２〉０给出了方差分量的线性函数的不变二次无偏估计、不变二次非负估计及不变二次估计不可容许的充要条件，并据此给出了具体判别上述估计的可容许性的方法。     

A Necessary and Sufficient Condition for Admissibility of Nonnegative Quadratic Estimator

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Estimation of covariance matrices in fixed and mixed effects linear models

The estimation of the covariance matrix or the multivariate components of variance is considered in the multivariate linear regression models with effects being fixed or random. In this paper, we propose a new method to show that usual unbiased estimators are improved on by the truncated estimators. The method is based on the Stein–Haff identity, namely the integration by parts in the Wishart distribution, and it allows us to handle the general types of scale-equivariant estimators as well as the general fixed or mixed effects linear models.     

An Algorithmic Approach to Discrete Time Non-homogeneous Backward Semi-Markov Reward Processes with an Application to Disability Insurance

In this paper semi-Markov reward models are presented. Higher moments of the reward process is presented for the first time applied to in time non-homogeneous semi-Markov insurance problems. Also an example is presented based on real disability data. Different algorithmic approaches to solve the problem is described. This work is partly supported by the Knowledge Foundation and Sparbankens Stiftelse Nya. The authors would like to thank the anonymous referee.     

Bayesian hierarchical linear mixed models for additive smoothing splines

Bayesian hierarchical models have been used for smoothing splines, thin-plate splines, and L-splines. In analyzing high dimensional data sets, additive models and backfitting methods are often used. A full Bayesian analysis for such models may include a large number of random effects, many of which are not intuitive, so researchers typically use noninformative improper or nearly improper priors. We investigate propriety of the posterior for these cases. Our findings extend known results for normal linear mixed models to certain cases with Bayesian additive smoothing spline models. Supported by National Science Foundation grant SES-0351523 and by National Institutes of Health grants R01-CA100760 and R01-MH071418.     

Dispersion of mass and the complexity of randomized geometric algorithms

How much can randomness help computation? Motivated by this general question and by volume computation, one of the few instances where randomness provably helps, we analyze a notion of dispersion and connect it to asymptotic convex geometry. We obtain a nearly quadratic lower bound on the complexity of randomized volume algorithms for convex bodies in Rn (the current best algorithm has complexity roughly n⁴, conjectured to be n³). Our main tools, dispersion of random determinants and dispersion of the length of a random point from a convex body, are of independent interest and applicable more generally; in particular, the latter is closely related to the variance hypothesis from convex geometry. This geometric dispersion also leads to lower bounds for matrix problems and property testing.     

茵陈挥发油GC-MS指纹图谱分析

建立了茵陈挥发油GC-MS指纹图谱,将正交投影算法用于不同样本中共有峰的提取,提高了共有峰的识别能力,降低了由于保留时间的漂移、质谱检索匹配度不高以及色谱峰重叠而引起的共有峰识别的难度.采用共有峰率、变异率及相似度等几个指标对4个不同产地的茵陈挥发油成分进行了评价,从共性、差异和整体性等多个方面全面表征茵陈挥发油的化学模式特征.结果表明,不同产地的茵陈挥发油成分大致相同,该指纹图谱可用于茵陈中挥发油成分的质量控制.     

RANDOM VARIABLE WITH FUZZY PROBABILITY

IntroductionThematteroffuzzyrandomisusuallyclassifiedintothreeparts:fuzzyevent_exactitudeprobabilitymodel,crispevent_fuzzyprobabilitymodel,fuzzyevent_fuzzyprobabilitymodel.Uptonow ,themajorityofresearchesandachievementsareaboutthefirstmodel,buttherearefewresearchesandachievementsaboutthesecondmodel[1- 4].Whenresearchingthesecondmodel,thefuzzyprobabilityaboutcertainbasiceventsmustbegivenfirst,andthefuzzinessofvariablesiscausedbythefuzzyprobabilityaboutthesebasicevents.Theabove_mentionedrelation…