Randomly weighted sums of linearly wide quadrant-dependent random variables with heavy tails

This paper investigates tail behavior of the randomly weighted sum ∑ⁿ_{k = 1}θ_kX_k and reaches an asymptotic formula, where X_k, 1 ? k ? n, are real-valued linearly wide quadrant-dependent (LWQD) random variables with a common heavy-tailed distribution, and θ_k, 1 ? k ? n, independent of X_k, 1 ? k ? n, are n non-negative random variables without any dependence assumptions. The LWQD structure includes the linearly negative quadrant-dependent structure, the negatively associated structure, and hence the independence structure. On the other hand, it also includes some positively dependent random variables and some other random variables. The obtained result coincides with the existing ones.     

Modeling Correlated Discrete Uncertainties in Event Trees with Copulas

Modeling the dependence between uncertainties in decision and risk analyses is an important part of the problem structuring process. We focus on situations where correlated uncertainties are discrete, and extend the concept of the copula‐based approach for modeling correlated continuous uncertainties to the representation of correlated discrete uncertainties. This approach reduces the required number of probability assessments significantly compared to approaches requiring direct estimates of conditional probabilities. It also allows the use of multiple dependence measures, including product moment correlation, rank order correlation and tail dependence, and parametric families of copulas such as normal copulas, t‐copulas, and Archimedean copulas. This approach can be extended to model the dependence between discrete and continuous uncertainties in the same event tree.     

Standing Up for the Victim,Siding with the Bully or Standing by? Bystander Responses in Bullying Situations

In this study we examined children's self‐efficacy, outcome expectations, and outcome values in relation to bystander responses in bullying situations. We proposed that beyond the effect of self‐efficacy, the decision to defend the victim of bullying vs. remain passive vs. reinforce the bully depends on outcomes children expect from defending, and on the value they place on these outcomes. Our sample consisted of 6397 Finnish children (3232 girls and 3165 boys) from third, fourth, and fifth grades (mean ages 9–11 years). Results showed that the motivational underpinnings of defending the victim, remaining passive, and reinforcing the bully varied. Defending was associated with the expectation that the victim feels better as a result of defending as well as valuing such an outcome. Reinforcement of bullying was associated with negative expectations and not caring about the positive outcomes. Conflicting expectations and values were linked to remaining passive. Results are discussed in terms of their implications for anti‐bullying interventions.     

Back to basics: explaining sample size in outcome trials,are statisticians doing a thorough job?

Time to event outcome trials in clinical research are typically large, expensive and high‐profile affairs. Such trials are commonplace in oncology and cardiovascular therapeutic areas but are also seen in other areas such as respiratory in indications like chronic obstructive pulmonary disease. Their progress is closely monitored and results are often eagerly awaited. Once available, the top line result is often big news, at least within the therapeutic area in which it was conducted, and the data are subsequently fully scrutinized in a series of high‐profile publications. In such circumstances, the statistician has a vital role to play in the design, conduct, analysis and reporting of the trial. In particular, in drug development it is incumbent on the statistician to ensure at the outset that the sizing of the trial is fully appreciated by their medical, and other non‐statistical, drug development team colleagues and that the risk of delivering a statistically significant but clinically unpersuasive result is minimized. The statistician also has a key role in advising the team when, early in the life of an outcomes trial, a lower than anticipated event rate appears to be emerging. This paper highlights some of the important features relating to outcome trial sample sizing and makes a number of simple recommendations aimed at ensuring a better, common understanding of the interplay between sample size and power and the final result required to provide a statistically positive and clinically persuasive outcome. Copyright © 2009 John Wiley & Sons, Ltd.     

Dependence function for continuous bivariate densities

The notion of cross-product ratio for discrete two-way contingency table is extended to the case of continuous bivariate densities. This results in the “local dependence function” that measues the margin-free dependence between bivariate random variables. Properties and examples of the dependence function are discussed. The bivariate normal density plays a special role since it has constant dependence. Continuous bivariate densities can be constructed by specifying the dependence function along with two marginals in analogy to the construction of two-way contingency tables given marginals and patterns of interaction. The dependence function provides a partial ordering on bivariate dependence.     

辽宁“十二五”工业经济发展规划的战略思考——基于产业竞争力的视角

基于产业竞争理论分析辽宁工业经济发展的现状，针对其中存在的利润率低、工业内部配套能力弱、产业之间发展不协调和民间投资被挤出等结构性问题分析其产生原因，认为政府主导资源推动型的发展方式和政府产业规划的雷同性及路径依赖性是造成结构性失衡的主要原因。为此，建议政府在编制辽宁“十二五”工业经济发展规划时应考虑效益指标，按产业发展周期和要素、需求条件等规划重点发展产业，并处理好支柱产业与支撑产业、相关产业之间的关系。     

A generalized negative binomial and applications

A generalized negative binomial distribution is derived from the Markov Bernoulli sequence of successes and failures. We study the properties and applications of this distribution. The properties are illustrated by two examples of discrete time queueing systems. The distribution is then fitted to two data sets, the eruption record of Mt. Sangay, and a record of computer disk failure accesses. In the first case there is a strong serial dependence in the data and the generalized negative binomial provides a good fit, while in the second case, although there is a significant serial dependence, it is insufficient to justify the additional parameter of the distribution. We conclude by demonstrating the usefulness of the distribution in the field of statistical quality control.     

试论中国社团的“官办”特性——路径依赖分析

新制度经济学中的路径依赖理论认为,路径依赖的产生源于旧体制中既得利益集团的阻挠和非正式制度安排的影响,而打破"锁定"状态除了从自身寻求出路外,往往还要借助于外部效应。这一理论对于解释中国社团的官办特性具有较强的适用性。中国社团的官办特性说到底是计划体制下的一种路径依赖,倘若对造成社团官办特性的种种路径依赖因素进行有意识的制度创新,将有助于减少路径依赖的负面影响,使我国的社团更能朝着良性的轨迹发展。     

Strong laws of large numbers for dependent heterogeneous processes: a synthesis of recent and new results

This paper surveys recent developments in the strong law of large numbers for dependent heterogeneous processes. We prove a generalised version of a recent strong law for Lz-mixingales, and also a new strong law for Lpmixingales. These results greatly relax the dependence and heterogeneity conditions relative to those currently cited, and introduce explicit trade-offs between dependence and heterogeneity. The results are applied to proving strong laws for near-epoch dependent functions of mixing processes. We contrast several methods for obtaining these results, including mapping directly to the mixingale properties, and applying a truncation argument.     

社会认知偏差:群体性事件生成的社会心理启动根源

社会认知偏差是群体性事件生成的深层次社会心理现象,通过对山东部分地区进行抽样调查,并结合近几年来全国群体性事件典型案例的分析发现,生成群体性事件的社会认知偏差,主要包括事件诱因责任归因偏差、行为模式结果预期偏差和行为结果价值偏差。因此,改善法的实施现状,消除社会认知偏差;提高公众法律意识,优化社会认知;建立心理危机干预队伍,合理引导社会认知,是群体性事件社会认知偏差的有效干预对策。