Maximum Likelihood Estimation of a Poisson Parameter in a Model of Equioverlapping Samples:A Simulation Study

In a model of equioverlapping samples maximum likelihood estimation of a Poisson parameter is examined and compared with two linear unbiased estimations by mean squared error. Since a likelihood estimator is not explicitly available in general, a simulation study has been performed and the results are illustrated     

壮傣、侗水群体分化年代考

操壮侗语族壮傣语支语言的壮、布依、傣、泰、佬等族以及操侗水语支语言的侗、水、仫佬、毛南等族,同源异流,都源于上古分布于我国南方的越人。操壮傣语支语言的群体与操侗水语支语言群体的分化,可能是在原始母权制氏族社会晚期。     

论信托的合并与分立--基于比较的视角

信托的合并与分立属于信托变更范畴,具有降低管理成本、提升管理效率和实现规模经济等效用,在域外民事信托和商事信托中得到了广泛的运用。由于信托的合并与分立关系到受益人、信托债权人等利害关系人的利益,比较法上多比照公司合并与分立时的规定,规定相应的通知公告、异议程序。中国《信托法》第5章不仅未规定信托变更的一般条款,也未在此基础上对信托合并、分立予以规范,未来应予完善,以适应信托效率化的需求。     

和谐与分裂的双重变奏——论海子诗歌中的身体意象

海子以身体投入诗歌创作中,使其诗歌出现了大量的身体意象。这些身体意象总体可归为两种,一种是带给人稳定亲切感的和谐的身体意象,一种是带给人撕裂苦闷感的分裂的身体意象,这些意象涉及身体与自然、身体与欲望、身体与死亡、身体的有限性、历史的肉身化等多个方面。海子诗歌中身体意象呈现和谐与分裂双重变奏的原因既与海子的诗学观有关,也与海子个人的身心遭际、时代环境以及他对人类命运的思索相联。     

Order statistics from overlapping samples: bivariate densities and regression properties

In this paper, we are interested in the joint distribution of two order statistics from overlapping samples. We give an explicit formula for the distribution of such a pair of random variables under the assumption that the parent distribution is absolutely continuous. We are also interested in the question to what extent conditional expectation of one of such order statistic given another determines the parent distribution. In particular, we provide a new characterization by linearity of regression of an order statistic from the extended sample given the one from the original sample, special case of which solves a problem explicitly stated in the literature. It appears that to describe the correct parent distribution it is convenient to use quantile density functions. In several other cases of regressions of order statistics we provide new results regarding uniqueness of the distribution in the sample.     

Estimating and testing group effects from type i censored normal samples in experimental design

The maximum likelihood (ML) equations calculated from censored normal samples do not admit explicit solutions. A principle of modification is given and modified maximum likelihood (MML) equations, which admit explicit solutions, are defined. This approach makes it possible to tackle the hitherto unresolved problem of estimating and testing hypotheses about group-effects in one-way classification experimental designs based on Type I censored normal samples. The MML estimators of group-effects are obtained as explicit functions of sample observations and shown to be asymptotically identical with the ML estimators and hence BAN (best asymptotic normal) estimators. A statistic t is defined to test a linear contrast of group-effects and shown to be asymptotically normally distributed. A numerical example is presented which illustrates the procedure.     

基于论元NP的作格分裂的语用阐释

以跨语言语料为基础,从语用学视角探讨了基于作论元的名词短语（NP）的语义性质的作格分裂模式。格结构中的论元NP具有指示性。将充当论元的NP按指示性的强弱分为不同的NP类,即为NP指示性等级。调查表明,基于NP指示性等级的作格分裂模式不仅适用于格标语言,也适用于汉语这样的非格标语言。在上述讨论的基础上,分析了汉语的作格分裂模式。     

供需未匹配的多车场多车型多货品可拆分取送货车辆路径问题

取送货车辆路径问题在多点调拨系统普遍存在,属于NP-hard问题。该问题研究通常需考虑车场数、车型种类、货品种类、客户服务次数等诸多因素,已有文献多假设客户间供需已匹配、单车场、单车型、单货品和取送货需求一次性满足,优化目标多设置为总路径最短。而从企业运营实践来看,运输方案不仅要规划客户间访问路径,还需进行客户间供需匹配;运输成本不仅与运距有关,还涉及运输货品的重量和派车成本;运输网络中多车场、多车型和多货品更加常见,且客户需求量往往大于车辆装载能力。因此,本文首次尝试基于"运距×运量"的车辆路径成本和基于额定吨位的固定派车成本之和最小为优化目标,建立同时考虑多车场、多车型、多货品、客户间供需未匹配和需求可拆分的取送货车辆路径问题模型,并设计基于大规模邻域搜索的迭代局部搜索求解算法。该算法采用基于运输效率提升的贪婪思想来快速构建高质量初始可行解,并通过引入四种移除算子、两种修复算子和车场车型调整优化策略形成大规模可行搜索邻域以增强全局寻优能力。基于18个文献算例和6个企业实例的数值实验结果表明：1）本文提出的算法在求解质量和求解效率方面均优于相关文献中的算法;2）相对人工调拨方案,本文设计的方案能够帮助企业节约33%的运输成本和21%的车次。本研究不仅可拓展取送货车辆路径问题现有理论,而且可为企业实际运营提供决策支持。     

Attacking the Market Split Problem with Lattice Point Enumeration

The market split problem was proposed by Cornuéjols and Dawande as benchmark problem for algorithms solving linear systems with 0/1 variables. Here, we present an algorithm for the more general problem A · x = b with arbitrary lower and upper bound on the variables. The algorithm consists of exhaustive enumeration of all points of a suitable lattice which are contained in a given polyhedron. We present results for the feasibility version as well as for the integer programming version of the market split problem which indicate that the algorithm outperforms the previously published approaches to this problems considerably.     

基于户籍制度改革的“成都样本”思考

2003年成都统筹城乡发展以来陆续改革户籍政策,并于2010年底出台了《关于全域成都城乡统一户籍实现居民自由迁徙的意见》。《意见》引发了国内舆论界和理论界的热评。笔者仅以成都的户籍制度改革为样本,从制度变迁的角度阐释户籍制度改革的核心与重点,并以此为基础,分析成都户籍制度改革的路径,提出进一步推进户籍制度改革面临的难题,以为我国其它省市户籍制度改革提供经验借鉴。