Behavior in Repeated Prisoner's Dilemma Games with Shifted Outcomes Analyzed with a Statistical Learning Model

A fuzzy set theoretical framework is proposed for the analysis of sociometric structure characterized by vagueness of liking between individuals and a person's relative degree of belonging to a social group. Max‐min transitivity of a fuzzy relation is employed as a basic concept to examine the degree of liking and clustering in group structures. A distance model based on min‐max transitivity is also formulated as a special case of transitivity analysis. Other notions of transitivity such as the max‐product and the max‐* are also discussed. An empirical analysis is performed to examine the applicability of the proposed transitivity concepts. It appears that the current methodological construct provides a more appropriate perspective in the analysis of the group structure properties.     

西藏地区近地晴天大气电场气象效应和时间变化研究

基于西藏羊八井宇宙线观测站在2006年3月至2011年6月期间记录的近地大气电场数据, 分析研究了该地区近地晴天大气电场气象效应和时间变化特征. 气象效应分析结果显示, 该地区近地晴天大气电场与三个气象参量(大气压强、温度和相对湿度)的长时间变化趋势基本一致, 并有明显的季节效应. 冬春季, 大气电场强度整体水平相对较低, 约为0.14 kV/m; 夏秋季, 电场强度水平相对较高, 为0.18 kV/m左右. 近地晴天大气电场强度与大气温度间的线性相关性最强, 拟合相关系数达到0.89; 与大气压强和相对湿度间的线性相关性相对较弱, 拟合相关系数依次为0.43和0.53. 傅里叶分析结果表明: 晴天大气电场时间变化受太阳日周期、半太阳日周期及其三、四次谐波分量调制作用, 调制强度依次减弱. 西藏地区近地晴天大气电场日变化特征呈大陆简单型, 即双峰双谷. 主、次峰谷分别出现在白天和夜间, 主峰谷出现的早晚因季节不同略有差异, 次峰谷出现的早晚因季节不同差异相对较大.     

均值方差偏好和期望损失风险约束下的动态投资组合

本文在均值方差框架下,研究了期望损失风险约束下的连续时间动态投资组合问题。运用鞅理论和凸对偶方法,分别给出了最优财富和最优投资策略的解析式,而且两基金分离定理仍然成立。最后通过数值例子分析了风险约束对最优投资策略的影响。     

Strict and tolerant antidivision queries with ordinal layered preferences

In this paper, we are interested in taking preferences into account for a family of queries inspired by the antidivision. An antidivision query aims at retrieving the elements associated with none of the elements of a specified set of values. We suggest the introduction of preferences inside such queries with the following specificities: (i) the user gives his/her preferences in an ordinal way and (ii) the preferences apply to the divisor which is defined as a hierarchy of sets. Different uses of the hierarchy are investigated, which leads to queries conveying different semantics and the property of the result delivered is characterized. Furthermore, the case where a conjunctive stratified antidivision query returns an empty set of answers is dealt with, and an approach aimed at relaxing such queries is proposed.     

Niveloids and their extensions: Risk measures on small domains

Given a functional defined on a nonempty subset of an Archimedean Riesz space with unit, necessary and sufficient conditions are obtained for the existence of a (convex or concave) niveloid that extends the functional to the entire space. In the language of mathematical finance, this problem is equivalent to the one of verifying if the policy adopted by a regulator is consistent with monetary risk measurement, when only partial information is available.     

A survey on the linear ordering problem for weighted or unweighted tournaments

In this paper, we survey some results, conjectures and open problems dealing with the combinatorial and algorithmic aspects of the linear ordering problem. This problem consists in finding a linear order which is at minimum distance from a (weighted or not) tournament. We show how it can be used to model an aggregation problem consisting of going from individual preferences defined on a set of candidates to a collective ranking of these candidates.      

COUNTING FAIR NEAR-TRIANGULATIONS ON THE DISC

1IntroductionAp1anarmaPisrootedifauedgeandadirectionalongonesideofitaredistinguished;atriangulationissucharootedplanarmapwhosefaCesareall3-gons;anear-triangulationonthe8phereordiscisarootednonseparableplanarmapsuchthatallofitsfacesexceptpossiblytheroot-faCehavevalencythree.TheenumerationoftriangulationswasfitStintroducedbyTUtteinthebeginningofsixtiesIv9].Infact,thetopicsheworkedweremuchconcentratedonplanartriangularmapsforthesakeofattackingFourColorProblem.Manyelegantresultsrelatedtononsep…     

流量转发中改进的加权公平排队策略

本通过网络节点流量转发实例的研究，发现传统的加权公平排队方法具有一定的局限性。并根据实际网络流量的特点，提出了一种改进的加权公平排队方法。实验结果表明，该方法具有更好的性能和更强的自适应性。     

Examining risk attitudes

The existence of risky choices makes the study of attitudes toward risk important. In this article we ask the following questions: Do risk‐neutral preferences maximize utility? Are there other measures of social welfare that can explain risk aversion in society? What effect does evolution have on the distribution of risk attitudes and the measures of social welfare? In a static environment risk‐neutral risk attitudes maximize utilitarian measures of social welfare, and risk‐averse attitudes maximize Rawlsian measures. In a dynamic system agents will tend toward risk, preferring greater affinity for risk when they can accumulate wealth. © 2004 Wiley Periodicals, Inc. Complexity 9: 25–30, 2004     

Preferences for contractual forms in supply chains

The supply chain contracting literature has focused on incentive contracts designed to align supply chain members’ individual interests. A key finding of this literature is that members’ preferences for contractual forms are often at odds: the upstream supplier prefers relatively complex contracts that can coordinate the supply chain; however, the downstream retailer prefers a wholesale price-only contract because it leaves more surplus (than does a coordinating contract), which the retailer can capture. This paper addresses the following question: Under what circumstances do suppliers and retailers prefer the same contractual form? We study supply chain members’ preferences for contractual forms under three different competitive settings in which multiple supply chains compete to sell substitutable products in the same market. Our analysis suggests that both upstream and downstream sides of the supply chain may prefer the same “quantity discount” contract, which would eliminate the conflicts of interest that otherwise typify contracting situations. More interesting still is that both sides may also prefer the wholesale price-only contract; this finding provides a theoretical explanation for why that inefficient (but simple) contract is widely adopted in supply chain transactions.