Bayesian inference for dynamic social network data

We consider a continuous-time model for the evolution of social networks. A social network is here conceived as a (di-) graph on a set of vertices, representing actors, and the changes of interest are creation and disappearance over time of (arcs) edges in the graph. Hence we model a collection of random edge indicators that are not, in general, independent. We explicitly model the interdependencies between edge indicators that arise from interaction between social entities. A Markov chain is defined in terms of an embedded chain with holding times and transition probabilities. Data are observed at fixed points in time and hence we are not able to observe the embedded chain directly. Introducing a prior distribution for the parameters we may implement an MCMC algorithm for exploring the posterior distribution of the parameters by simulating the evolution of the embedded process between observations.     

Normal approximation to the hypergeometric distribution in nonstandard cases and a sub-Gaussian Berry–Esseen theorem

In this paper, we consider simple random sampling without replacement from a dichotomous finite population. We investigate accuracy of the Normal approximation to the Hypergeometric probabilities for a wide range of parameter values, including the nonstandard cases where the sampling fraction tends to one and where the proportion of the objects of interest in the population tends to the boundary values, zero and one. We establish a non-uniform Berry–Esseen theorem for the Hypergeometric distribution which shows that in the nonstandard cases, the rate of Normal approximation to the Hypergeometric distribution can be considerably slower than the rate of Normal approximation to the Binomial distribution. We also report results from a moderately large numerical study and provide some guidelines for using the Normal approximation to the Hypergeometric distribution in finite samples.     

跨国公司扩大对华R&D投资的影响与对策

跨国公司在华R＆D投资的发展会对我国的企业、产业、技术创新和技术进步带来什么样的影响?能否达到我国吸引跨国公司R＆D投资所期望的战略目标和层次?这是人们所普遍关心和想深入了解的一个问题。本文探讨了跨国公司在华R＆D投资的内在动因与挑战问题;分析了我国吸引跨国公司R＆D投资的多重需求和效应;提出了促使我国吸引跨国公司R＆D投资有效目标实现的应对策略。     

试论罗斯福"新政"与黑人民权问题

罗斯福政府并没有给予黑人真正的"新政",也没有为促进黑人民权的发展采取重大举措。但是罗斯福政府在大萧条时期所采取的救济措施,以及联邦政府扩大对黑人知名人士的任命,使黑人看到了民主党统治下的联邦政府可以成为黑人争取民权的工具。罗斯福"新政"也因此改变了多数黑人在政治上的政党选择,对日后美国的政治生活和黑人争取民权的斗争产生了深远的影响。     

劳伦斯的阿芙罗狄特情结

戴·赫·劳伦斯一生崇拜阿芙罗狄特,他津津乐道的血意识其实是阿芙罗狄特精神的现代阐释,而小说《查特莱夫人的情人》则是对这种精神的形象表达,隐喻作者一贯坚持的只有性爱才能拯救人类的思想主题。     

第三种势力--政治视角中的鸿都门学

鸿都门学是由汉灵帝独立发起并组织的 ,其初衷和实际并不是直接针对党锢之士的 ,而是针对东观、太学等清流士人 ,同时也是针对宦官集团的 ,因此鸿都门学是汉灵帝执政时代的第三种政治势力。它介于清流与浊流之间 ,是汉灵帝试图依赖的一种新兴的政治力量     

A comparison of conditional Poisson sampling versus unequal probability sampling with replacement

The variance of the Horvitz–Thompson estimator for a fixed size Conditional Poisson sampling scheme without replacement and with unequal inclusion probabilities is compared to the variance of the Hansen–Hurwitz estimator for a sampling scheme with replacement. We show, using a theorem by Gabler, that the sampling design without replacement is more efficient than the sampling design with replacement.     

农业龙头企业R＆D与企业成长关系研究

农业龙头企业在农业产业化经营中具有关键作用 ,对农业龙头企业如何实现持续成长的探讨 ,成了当前研究热点之一。文章主要从技术创新角度分析农业龙头企业成长 ,在已有研究基础上 ,探讨龙头企业R&D与企业成长之间的互动机理及其环境契合。认为 ,在一定条件下 ,农业龙头企业R&D与企业成长之间存在正反馈关系 ,契合的企业成长环境会加强二者的互动关系。     

两汉民俗区研究

民俗的重要特征是地域性,民俗区研究对研究区域历史文化有重要意义。自司马迁起,就开始将两汉民俗区划分为9个,后又有刘向、朱赣把全国划为13个民俗区,17个民俗亚区;今人周振鹤先生重新组合《汉书·地理志》的资料,把两汉民俗区划为三大民俗区域,16个民俗区,15个民俗亚区。以上划分法都有一定的缺憾,应划为四大民俗带:长城民俗带、黄河民俗带、长江民俗带、珠江民俗带。民俗区的形成有自然环境和政治环境的影响,相对南方而言,北方地区民俗受社会政治环境的影响更大一些。     

城市三维地层信息系统的提出与思考

根据城市建设的实际情况，阐述了建立三维地层信息系统的意义，并针对当前地理信息系统发展的状况，提出了建立城市三维地层信息系统的思路．