Bootstrapping the renewal spacings processes

We define the generalized bootstrapped version of the empirical and quantile renewal spacing processes. We show that the asymptotic theory of the renewal spacings processes holds for the bootstrap version.     

Perturbation analysis for an orthogonal least-squares estimator

Coordinate measuring machines (CMMs) are used to check the geometric integrity of component parts. The geometric constraints to which a part must conform, as defined e.g., by The American National Standards Institute, assume the use of some type of gauging system when inspecting the part. Statistical issues arise in interpretting CMM data in the inspection of part tolerances. We consider a set of n planar regions on the surface of a part. The unit vector normal to each plane is estimated by orthogonal least squares. The small-sample density of this estimator (on the unit sphere S²) is determined asymptotically as the variance of the CMM error approaches 0. To a first-degree approximation, this density is Fisher-von Mises. Diagnostics are reviewed to test the geometric constraint that the n planar regions are oriented correctly with respect to one another, and to test the flatness of planar regions.     

含卤族元素的试剂对二级醇的选择性氧化

醇的氧化在合成化学中具有很重要的位置。随着近年来不断的研究和探索,醇的氧化选择性越来越高。本文列举了一些含卤族元素的氧化剂对不同种类醇的选择性氧化实例。     

基于企业知识积累的研发人员激励模型

按照知识基础论的观点,分析研发人员对企业的双重贡献,其贡献不仅体现在直接为企业带来当期利润与市场价值,还可以提升企业知识存量,进而使企业获取持续技术创新能力和竞争优势。结果表明,运用博弈论的分析方法,构建了一个基于企业知识积累的研发人员激励动态模型。分析指出,一个有效的研发激励机制,应该使风险收入在研发人员的报酬中占相当比重,考虑研发人员的风险承受能力及其努力的成本,与企业知识积累的数量和质量的提高挂钩。     

Two remarks on order statistics

Let X₍₁₎,…,X_(n) be the order statistics of n iid distributed random variables. We prove that (X_(i)) have a certain Markov property for general distributions and secondly that the order statistics have monotone conditional regression dependence. Both properties are well known in the case of continuous distributions.     

Confidence regions for the common mean vector of several multivariate normal populations

Suppose that there are independent samples available from several multivariate normal populations with the same mean vector m? but possibly different covariance matrices. The problem of developing a confidence region for the common mean vector based on all the samples is considered. An exact confidence region centered at a generalized version of the well-known Graybill-Deal estimator of m? is developed, and a multiple comparison procedure based on this confidence region is outlined. Necessary percentile points for constructing the confidence region are given for the two-sample case. For more than two samples, a convenient method of approximating the percentile points is suggested. Also, a numerical example is presented to illustrate the methods. Further, for the bivariate case, the proposed confidence region and the ones based on individual samples are compared numerically with respect to their expected areas. The numerical results indicate that the new confidence region is preferable to the single-sample versions for practical use.     

我国住宅二级市场存在的问题及对策

说明了住宅业在国民经济中的重要性以及住宅二级市场的内涵 ;分析了目前住宅二级市场存在的开放程度不够 ,房屋确权不明确 ,中介服务不规范等多方面的问题 ;并提出笔者的几点建议思考 ,旨在开放住宅二级市场以促进我国住宅产业的新发展     

论中、高等职业技术教育的衔接

中、高等职业技术教育衔接的渠道不畅 ,这是影响我国职教整体快速发展的一个原因 ,也是一个急需解决的问题。中、高等职技教育的衔接有其必要性、可行性 ,两者的衔接有一定的原则与形式     

Estimating the probability of winning (losing) in a gambler's ruin problem with applications

In a classical gambler's ruin problem, the distribution of the number of games lost till ruin is considered, which we call the lost game distribution (LGD). Some applications of LGD in the theory of queues, in the theory of epidemic and in certain clustering and branching models are mentioned. The maximum likelihood estimation of LGD in the framework of modified power series distribution (MPSD), introduced by the author (1974), is studied. The variance and bias of the MLE are given and the actual mean of the MLE is obtained by discussing the negative moments of the MPSD in general. The minimum variance unbiased estimator of θ^k (k≥1) is obtained employing the technique developed by the author (1977) for the class of MPSD.     

Emergency stocks: A theoretical analysis and an illustration for Israel

The paper develops a methodology for designing and evaluating the performance of emergency stocks. The system is required to meet consumers' demands in all emergency situations at a given level of reliability and least possible costs. The model takes into account the various stochastic elements that determine the performance of the system, including the frequency of emergency situations and their expected duration, the pace of replenishing the stocks, the consumption rate in an emergency situation, and the opportunity for stock building prior to the occurance of an emergency on the basis of advance information about the severity of the strategic situation.