Estimation of P{X < Y} for geometric—exponential model based on complete and censored samples

This article deals with the estimation of R = P{X < Y}, where X and Y are independent random variables from geometric and exponential distribution, respectively. For complete samples, the MLE of R, its asymptotic distribution, and confidence interval based on it are obtained. The procedure for deriving bootstrap-p confidence interval is presented. The UMVUE of R and UMVUE of its variance are derived. The Bayes estimator of R is investigated and its Lindley's approximation is obtained. A simulation study is performed in order to compare these estimators. Finally, all point estimators for right censored sample from the exponential distribution, are obtained.     

Strength matters: Tie strength as a causal driver of networks’ information benefits

Studies of social networks have often taken the existence of a social tie as a proxy for the transmission of information. However, other studies of social networks in the labor market propose that the likelihood of information transmission might depend on strength of the tie; and that tie strength is a potentially important source of the tie's value. After all, even if job seekers have social ties to those who have valuable job information, the seekers will gain little information benefit when the ties do not actually transmit the information. This paper clarifies the conditions under which social ties might provide information benefits. We use a survey vignette experiment and ask MBA students about their likelihood of relaying job information via strong ties (to friends) or weak ties (to acquaintances), holding constant the structural locations spanned by the tie and job seekers' fit with the job. The results support the claim that strength of tie has a causal effect on the chances of information transmission: potential referrers are more likely to relay job information to their friends than to acquaintances. The larger implication of these findings is that whatever benefits there might be to using weak ties to reach distant non-redundant information during job search, these benefits need to be considered against the likely fact that people connected via weak ties are less likely to actually share information about job opportunities than are people to whom the job seeker is strongly tied.     

论建设国家中心城市——从国家战略层面全面提升广州科学发展实力的研究

国务院批准实施的《珠江三角洲地区改革发展规划纲要（2008—2020）》，从国家战略层面明确了广州作为国家中心城市的战略定位。如何建设国家中心城市、全面提升科学发展实力，成为广州在新的历史条件下的重大使命。本文从广州实际出发，就建设国家中心城市、全面提升科学发展实力进行了理论探讨和实证分析，并提出了相应的对策措施。     

当前称谓语的演变及其社会意义

本文通过对若干称谓语的演变的考察,认为称谓语的演变反映了社会生活的变迁,并具有一定导向力量,大多从经济文化发达地区向落后地区扩散。     

供应链整合跨度与强度二维互动演进机理研究

现阶段,企业与企业之间的竞争已经逐步转变为供应链与供应链之间的竞争,加强供应链管理已经逐渐成为企业获取竞争优势的重要策略,而促进供应链成员间的整合则是供应链管理成功的关键.基于以往的供应链整合研究,文章从供应链整合的两个维度——跨度与强度——出发,分别探讨供应链整合在两个维度上的演进机理,并指出供应链整合是供应链成员依赖于关系学习的两个维度相互作用、互动演进的有限过程,为供应链整合提供了新的理解角度,并辅以永辉超市供应链整合的案例加以验证.     

基于财政竞争力分析的福建省经济发展策略研究

财政对经济增长起着不可替代的促进作用,而财政竞争力也是经济综合竞争力的重要组成部分,分析福建省各地市的财政竞争力以寻找经济发展策略,对促进福建省经济有重大意义。本文对各地市财政收支现状进行初步比较,构建财政竞争力三级指标体系以分析财政竞争力水平,同时利用主成分因子得分分析财政竞争力与经济发展之间的关系。研究结果表明,厦门、福州及泉州财政竞争力较强,以这三个地市为例,从财政竞争实力和竞争潜力两个方面提出进一步提升财政竞争力的建议。     

高强混凝土高温性能研究进展

对近年来高强混凝土高温性能的研究成果进行了综述与分析,包括热工性、高温下和高温后力学性能以及高强高性能混凝土的爆裂性能。其中,高强混凝土热工性能方面的研究成果较少且研究结果离散性较大;高强混凝土力学性能方面的研究主要集中于抗压强度、抗拉强度、变形性能、弹性模量、泊松比、应力 应变关系等,而对高强混凝土结构、构件高温力学性能和温度场分析方面的研究较少;高强高性能混凝土爆裂方面的研究多集中于爆裂规律和爆裂抑制措施,对爆裂机理和微观结构的研究较少。本文分别从3个方面指出了高强混凝土高温性能研究中存在的问题和今后的研究方向,为深入研究高强混凝土的高温性能提供参考。     

基于因子分析的株洲各县市区 综合经济实力评价

市区经济发展离不开本市各个县市区经济的贡献,而本市各县市区发展之间的差异会影响整个市区的经济发展。株洲市近几年来发展迅速,但各县市区的发展却有很大差异。通过因子分析方法研究株洲市各县市区的综合经济实力问题,并根据株洲统计年鉴提出了14个反映城市综合经济实力的指标。研究结果反映了株洲市各县市区的经济发展之间差异,为株洲市经济发展提供了参考。     

Comparison of Interval Estimators of Pr(X < Y) in the Two-parameter Exponential Distribution

We consider confidence intervals for the stress–strength reliability Pr(X< Y) in the two-parameter exponential distribution. We have derived the Bayesian highest posterior density interval using non-informative prior distributions. We have compared its performance with the intervals based on the generalized pivot variable intervals in terms of their coverage probabilities and expected lengths. Our simulation study shows that the Bayesian interval performs better according to the criteria used, especially when the sample sizes are very small. An example is given.     

铝板件自冲铆接的实验分析

本文介绍了一种新型的铝板件冲压连接技术,并根据实验结果阐述了自冲铆接的机理,分析了铆钉和模具结构对连接性能的影响,并对自冲铆接与圆点冲压连接的强度进行对比.此外,本文对这种新型连接技术的实际应用作了简要介绍.