On the reciprocity of connections in weighted and unweighted networks

Bivariate Bernoulli and bivariate geometric distributions are proposed to model reciprocity in weighted and unweighted networks. Sampling properties of commonly used reciprocity measures are studied, under both presence and absence of reciprocity. Extensions to situations where link parameters depend on outgoing and incoming nodes are investigated. Results are illustrated with a data set, on 50 anesthesia providers at a hospital, that describes the number of times an anesthesia provider starting an operation transfers his/her responsibilities to another anesthesia provider.     

党政机构微博在突发事件中传播效果的影响因素及策略

在分析铁路货运量预测方法的基础上，针对标准BP神经网络的不足，提出改进的BP神经网络预测模型。首先,利用动态陡度因子来改变激励函数的陡峭程度，以此来得到更好的激励函数响应特征以及更好的非线性表达能力；其次，利用附加动量因子，通过对以前经验的积累，既降低了神经网络对误差曲面的局部细节敏感特性，又较好的遏制了神经网络易于限于局部最小的缺陷；最后，采取改变学习率的方法，给定一个较大的学习率初始值，在学习的过程中学习率不断减小，网络最终趋于稳定。改进BP算法既可以得到更优的解，还能够缩短训练时间。利用全国铁路货运     

Social network and family business: Uncovering hybrid family firms

What does it mean for a private enterprise in China to be embedded in a family? Our purpose here is twofold: (1) use social network analysis to describe what it means for a firm to be embedded in a family, (2) reveal from the application a new kind of firm, not family, yet akin to family. Armed with data on a large probability sample of private enterprises — a third of which meet ownership and employment criteria of being family businesses — we uncover a category of “hybrid family firms” that look modern in the style of firms that exclude family, but operate socially in ways similar to family firms. Our conclusion from summary statistics on the sample is that there are no differences in average performance level or network advantage for the three categories of businesses: family firms, hybrid family firms, and family-excluded firms. The fact that CEOs of family firms and hybrid family firms more often turn to family as key business contacts is a fact about network composition that raises no question about network mechanisms. Whether the CEO turns to more or fewer family contacts, government help is more likely with stronger political connections, and business success and survival are more likely with a large, open network. That said, the look-modern, act-traditional hybrid family firms stand alone in prospering with a CEO embedded in a closed business network. Recognition of hybrid family firms adds to the literature’s illustrations of social network analysis used to distinguish types of businesses and business people, and extends the population of organizations within which governance and strategy are likely to be better understood when viewed through a family logic.     

Reversible jump Markov chain Monte Carlo algorithms for Bayesian variable selection in logistic mixed models

In this article, to reduce computational load in performing Bayesian variable selection, we used a variant of reversible jump Markov chain Monte Carlo methods, and the Holmes and Held (HH) algorithm, to sample model index variables in logistic mixed models involving a large number of explanatory variables. Furthermore, we proposed a simple proposal distribution for model index variables, and used a simulation study and real example to compare the performance of the HH algorithm with our proposed and existing proposal distributions. The results show that the HH algorithm with our proposed proposal distribution is a computationally efficient and reliable selection method.     

基于消费者显著性偏好的双边平台转换成本和定价策略研究

针对消费者对转换成本和价格属性具有显著性偏好的实际情况，基于显著性理论对垄断双边平台企业的转换成本和定价策略问题进行了研究。研究发现：1)在显著性偏好非对称型市场上，对价格敏感的一方收取的价格最低，对高转换成本的一方收取的价格最高，而在显著性偏好对称型市场上，平台的最优价格位于非对称型市场之间，但是对价格敏感型市场收取的价格低于转换成本敏感型市场的价格。2)在高转换成本的市场，平台利润最低；低转换成本市场平台利润最高，而混合型情况的最优利润位于这两者之间。该研究结论说明平台企业应该采取措施来降低用户加入平台的转换成本，从而增加利润，这与现实的案例研究结论相吻合。     

Differences in meconium stained amniotic fluid in an Australian population: A retrospective study

Background

Meconium stained amniotic fluid commonly occurs postdates (?>40 weeks gestation) indicating fetal maturity. Previous literature indicates that different ethnicities mature at different rates.

Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning

Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well‐established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents’ relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor‐based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates.     

网络环境下服务科学与创新管理研究展望

基于网络环境的服务发展与创新已成为经济发展的新引擎。本文在分析网络环境下服务特征基础上，探讨了其对服务科学与创新管理研究的影响。结合我国社会经济发展对现代服务快速增长的需求，本文提炼了服务科学研究的三类基本科学问题，包括服务价值的内涵与度量，服务资源的要素及其价值生成，和服务关系的界定与形成问题；提出了服务与创新管理的四个重要研究领域，即：服务生态系统的形成与演化，服务资源要素的组织与协调，服务的关联与融合和社会服务运作管理问题。在四个重要研究领域的进一步分析中，论文以一个异质数据服务资源的组织与融合为例，描述了服务资源组织与协调的一个具体问题，说明了已有研究方法解决该问题的困难，和未来该问题研究需要关注的重点；另以平台服务中基于价值和关系的服务定价问题为例，说明服务关联与融合研究的挑战及其未来研究的努力方向。     

汉语网络语言影响内地藏生汉语习得的原因与对策

汉语网络语言影响藏生汉语习得的情感，影响藏生汉语习得中“可理解的语言输入”的数量和质量，影响藏生对汉语社会文化的适应和趋同程度。这些影响主要与汉语网络语言使用失范、内地藏生汉语习得与汉语网络环境脱节、汉藏文化障碍影响汉语网络语言的推介等因素相关。据此，文章从二语习得的角度提出解决对策：培养藏生对汉语网络语言的价值观和情感；引导和规范汉语网络语言，优化网络环境；寻求藏生汉语习得与网络社会生活的契合点，提高“可理解的语言输入”的数量和质量。