V aR 之下厚尾分布的最优资产组合的收敛性

主要研究在V aR 风险度量之下, 收益具有厚尾性质的资产的投资组合问题. 证明了基于 尾部分布二阶展开的最优投资组合收敛于基于尾部分布一阶展开的最优投资组合. 因此, 对于 V aR 风险度量之下的最优投资组合问题, 如果要求的风险承受水平充分低, 则只需要利用尾 部分布的一阶展开代替厚尾部分布进行近似计算, 就可以达到满意的精度, 从而不需要进行复 杂的高阶运算.     

Die Rolle von Psycholog/innen in den Medien

The role of psychologists in the mediaDiscribing the phenomena of frequently asking journalists the authors are trying to describe the social meaning of role-and functiontaking of the science of psychology in the public discussion. They are following the question whether it could be possible to publish scientific results without banalizing, taking part in voyerism and reprehensible emotion creating.     

Toward an Understanding of Russian Speaking Heroin Addicts and Drug Treatment Services in Israel

Abstract

This pa per de scribes the find ings from a pur pos ive sample of 152 male and fe male Rus sian-speak ing drug ad diets who im migrated to Is rael dur ing the last ten years. Ap prox i mately one-third of the co hort was not Jew ish, in clud ing 47 per cent of the women. Forty-one per cent of the subjects re ported be ing phys i cally abused and 25 per cent of the women, com pared to 5 per cent of the men, re ported be ing sex u ally abused as a child. Al co hoi abuse was found to be dif fer ent among the par ents of male and fe male ad diets: 46% of the women com pared to 31% of the men had fa thers who drank ex ces sively; 14% of the women compared to 5% of the men had moth ers who were heavy drink ers. Also, female ad diets were more likely than male ad diets to have a mother who used il licit drugs. Treat ment re lated is sues are dis cussed along with the need for specialized, culturally sen si tiveser vice pro vision.     

一种新的动态综合评价方法

在经济管理与决策中, 经常遇到大量的动态综合评价问题. 动态综合评价问题的核心是 评价指标在不同时刻的权重系数的确定. 针对由时序立体数据表支持的综合评价问题的特殊 性, 提出了一种新的确定权重系数的“‘纵横向’拉开档次”法, 并给出一个实际例子. 该方法具 有原理简单、直观意义明显、评价过程“透明”等特点.     

供应链分销系统优化及仿真

研究多个制造商多个分销商组成的分销系统, 综合考虑库存成本、订货成本、运输成本和 缺货成本, 建立了较为全面的分销网络成本模型, 以分销商满足市场需求时的服务水平作为优 化问题的约束条件, 求解成本优化问题. 然后, 给出了求解上述最优订货量的方法, 并用仿真方 法分析了价格参数及订货比例系数对总成本的影响. 结论表明: 随着运价参数b 的降低, 总成 本下降幅度较大; 分销商在地理位置方面的特征, 会影响分销商在不同供应商之间的最优订货 比例, 该比例不是越大越好, 也不是越小越好, 最优比例是居中的某个数值.     

Effective retirement age from employment and full‐time employment,and the impact of the 2008 crisis

Estimates of effective retirement age based on labour force participation rates are commonly used for actuarial experience review and policy development. However, the transition from work to retirement and the socio‐economic environment have evolved over the years, influenced by a growing role for gradual retirement and the labour market impact of the 2008 economic crisis. Rather than focusing exclusively on retirement ages based on labour force participation rates, this article presents complementary estimates of retirement ages to better assess the effective retirement age from employment. It also introduces the concept of retirement from full‐time employment, showing that the retirement age from full‐time employment is systematically lower than the retirement age from employment. The results reveal that the trend towards an increase in the retirement age has been impacted by economic conditions when considering the effective employment of older workers. Results are presented for different Member countries of the Organisation for Economic Co‐operation and Development over the period 2005–2015.     

农村剩余劳动力良性转移问题

随着我国经济改革的深入 ,农村剩余劳动力转移已成为历史的必然。农村剩余劳动力转移 ,对我国城乡经济的发展既有积极作用 ,也有消极影响。为此 ,应采取切实有效的政策措施 ,如国内的宏观协调和组织 ;发展乡镇企业和第二、三产业 ,进行农业内部转移和农村内部转移等 ,以实现农村剩余劳动力的良性转移     

Ordentlich in Unordnung?

One of the most prominent positions within German sociological discussions of recent social changes in the structures and processes reproducing gender differences and gender hierarchies is the concept of de-institutionalization. Heintz and Nadai, the authors of this concept, observe a fundamental shift in the dominating mode of reproducing gender, and claim that as a consequence of this shift gender is no longer a structuring principle of social order but has become a principle of disorder. The following article confronts this thesis with the empirical findings of the research programme “Professionalization, Organizations, and Gender” funded by the DFG from 1998 to 2004 and follows two questions: (1) Which professional and/or organizational contexts provide opportunities to de-gender professional work, which contribute to an ongoing gendering of and within professions and organizations? (2) Which developments, and contradictions come into view if we look at different social levels: the everyday knowledge of professionals, the interactive ways of doing or undoing gender, the gendered or degendered (sub)structure of organizations, and the macro structures of the gender system? In answering both questions the article comes to the conclusion that the everyday gender knowledge of professionals has undergone a process of rhetorical modernization but that social practices and (sub)structures are still dominated by the ‘old’ modes of reproducing gender, and the gender order.     

Triadic balance in the brain: Seeking brain evidence for Heider’s structural balance theory

Structural balance theory is a foundational theory of social network research. Despite enduring interest in seeking network evidence for the theory, the fundamental question of why people care about structural (im)balance has received relatively little attention. The original answer to the question, dating back to Heider’s work six decades ago, is that structural imbalance causes a person to experience cognitive dissonance and sentimental disturbance. In this paper, we used a state-of-the-art neuroimaging technique to test the argument. Our study shows that individuals’ psychological states, evidenced by the activation of brain areas, are different when they are situated in unbalanced rather than balanced triads. More specifically, the differences in the brain activation between triadic imbalance and balance were found in brain regions known for processing cognitive dissonance, as discovered by previous research. Our study provides novel brain evidence in support of Heider’s original account for the psychological and biological foundations of structural balance theory in the formation of social networks.     

“红包”现象的社会学思考

“红包”现象腐蚀社会机体,降低道德水准,严重危害国家政权健康.本文对这种腐败现象进行了批判,分析其产生原因,提出了有效遏制的对策建议,对加强党风廉政建设具有一定理论意义.