Effects of some design factors on the distribution of similarity indices in cluster analysis

This article investigates the effects of number of clusters, cluster size, and correction for chance agreement on the distribution of two similarity indices, namely, Jaccard and Rand indices. Skewness and kurtosis are calculated for the two indices and their corrected forms then compared with those of the normal distribution. Three clustering algorithms are implemented: complete linkage, Ward, and K-means. Data were randomly generated from bivariate normal distributions with specified means and variance covariance matrices. Three-way ANOVA is performed to assess the significance of the design factors using skewness and kurtosis of the indices as responses. Test statistics for testing skewness and kurtosis and observed power are calculated. Simulation results showed that independent of the clustering algorithms or the similarity indices used, the interaction effect cluster size x number of clusters and the main effects of cluster size and number of clusters were found always significant for skewness and kurtosis. The three way interaction of cluster size x correction x number of clusters was significant for skewness of Rand and Jaccard indices using all clustering algorithms, but was not significant using Ward's method for both Rand and Jaccard indices, while significant for Jaccard only using complete linkage and K-means algorithms. The correction for chance agreement was significant for skewness and kurtosis using Rand and Jaccard indices when complete linkage method is used. Hence, such design factors must be taken into consideration when studying distribution of such indices.     

交易获利机会损失的侵权损害赔偿

法经济学的一种通行观点认为,交易获利机会的损失在相当大的程度上并非"真实社会成本",而仅仅是不同市场主体之间的转移支付,因此原则上否定此种交易获利机会赔偿的侵权法规则具有合理性。提出该观点的早期文献系统性低估了交易获利机会损失事件引发的"真实社会成本"。实际上,如果坚持使用"真实社会成本"概念对侵权法规则进行分析,最终甚至会导致对物之损害赔偿的传统规则的正当性也发生疑问。适宜的作法是放弃"真实社会成本"概念而代之以"相对社会成本"概念,原则上将成本——收益分析限定于加害人与被害人之间的关系。按照此种思路,除第三人提供交易机会所导致的或具有合同法救济渠道的交易获利机会损失需要特殊处理外,并无效率方面的原则性理由支持侵权法一般性地排除交易获利机会损失的可赔性。     

Selective Maintenance in System Reliability with Random Costs of Repairing and Replacing the Components

In this paper we consider the problem of determining the optimum number of repairable and replaceable components to maximize a system's reliability when both, the cost of repairing the components and the cost of replacement of components by new ones, are random. We formulate it as a problem of non-linear stochastic programming. The solution is obtained through Chance Constrained programming. We also consider the problem of finding the optimal maintenance cost for a given reliability requirement of the system. The solution is then obtained by using Modified E-model. A numerical example is solved for both the formulations.     

加入WTO后我国合作金融机构面临的挑战、机遇及对策

本文通过分析我国加入WTO后 ,合作金融机构面临的冲击和挑战 ,并根据合作金融机构自身的特点、优势和机遇 ,提出相应的对策、建议     

互联网－思想政治工作的双刃剑

二十一世纪是信息化时代,而网络技术的迅猛发展对政治、经济、文化及社会生活等各个方面产生了广泛的影响,如何正确认识网络及其带给思想政治工作的机遇和挑战,积极寻找有效对策,是当前必须解决的一个新的政治课题。     

上海自贸试验区建设对中国经济转型:机遇和挑战

上海自贸试验区实行加快政府职能转变、扩大投资领域开放、推进贸易发展方式改变、深化金融领域开放创新等一系列任务和要求,提出改革管理模式、创新税收制度、实施相关产业政策和建立风险防御体系等政策和措施。这不仅可为其他地区经济改革提供了范例,更有利于中国经济从当前粗放型发展模式向集约型转变。但在转变的过程中,中国经济将面临如何平稳过渡的挑战。     

Chance constrained optimization for targeted Internet advertising

We introduce a chance constrained optimization model for the fulfillment of guaranteed display Internet advertising campaigns. The proposed formulation for the allocation of display inventory takes into account the uncertainty of the supply of Internet viewers. We discuss and present theoretical and computational features of the model via Monte Carlo sampling and convex approximations. Theoretical upper and lower bounds are presented along with a numerical substantiation.     

CHANCE OF MISCLASSIFICATION IN THE CASE OF SEVERAL NORMAL POPULATIONS

When a new observation is to be classified into one of several multivariate normal populations with different means and the same covariance matrix, by Rao's method of scoring, the chance of misclassification is expressed as a multiple integral. This paper gives a practical method of obtaining reasonable approximations to this integral by using tables prepared by Gibbons, Olkin & Sobel (1977) for a different task.     

浅析网络小说繁盛时代的隐忧

现今的网络小说进入了一个繁盛的时代,并引领着大众的阅读热潮,但在网络小说百花齐放的表象下却杂草丛生：网络小说对利益最大化的追逐导致了小说成了纯娱乐、纯感官刺激的消遣品,因此必然抛弃文学所坚守的精神追求,沦为商业时代下没有特色的商品,并大量复制,充斥市场,这对广大的读者来说是在不断吸收没有营养的精神快餐,有害无益。     

从“满洲国”的官僚体制看日本“民族协和”的虚伪性

1932年伪满洲国成立,伪东北行政委员会委员长张景惠以伪满洲国政府名义发表一系列所谓平等的言论;另一方面日伪政权所设立的伪满洲国官僚机构也以“民族协和”而冠冕堂皇之,但是在实际上却是由日本殖民者直接参政、操纵和控制傀儡政权。