具有卖空总量限制的多阶段M—SAD投资组合优化

文章提出具有卖空总量限制、阈值约束和V型交易成本的多阶段均值—半绝对偏差（M-SAD）投资组合优化模型。该模型分别运用均值和半绝对偏衡量资产的收益率和风险。由于交易成本的存在,该模型不满足无后效性的动态优化问题。文章将该模型近似为一般动态规划问题,提出一种新的离散迭代方法,并证明该算法是线性收敛的。最后,文章通过实证研究比较分析卖空总量限制和风险偏好系数取不同值时对投资组合最优策略的影响,验证模型和算法的有效性。     

湖南省红色资源赋能乡村振兴的多维价值与路径优化

乡村振兴战略的全面铺开为红色资源的有效开发利用提供了良好契机,而红色资源在推动乡村产业发展、促进农村基层治理、培育文明乡风、加强生态保护、增强文化自信等方面的多维价值也日渐凸显。湖南省作为中国近代革命的摇篮和红色文化的发源地,有着富集的红色物质资源、深厚的红色精神内涵和优良的红色革命传统,在充分发掘红色资源的多维价值以助力乡村全面振兴的实践方面具有得天独厚的优势,因此,需要在聚焦现实需求、采取有力措施、多层面精准发力的基础上,推动红色资源在“保护好”“管理好”的过程中顺利实现“利用好”的目标,将资源禀赋转化为发展优势,实现红色资源保育与乡村振兴的互动双促,从而加速推进乡村全面振兴。     

要素禀赋、农户分化与农业价值链技术选择偏向

基于551份猕猴桃种植户调研数据,通过聚类分析方法将猕猴桃种植户分成发展型、规模种植型、劳动力富裕型三类,实证检验种植户类型对有机肥施用、新品种采纳、猕猴桃网络销售三个价值链技术活动选择的异质偏向性,分析农机补贴、产业组织检测、技术培训三个组织支持变量的调节效应。结果发现：发展型对于三个价值链技术活动及其联合采纳的选择偏向性高于其他类型,劳动力富裕型种植户对价值链技术活动的选择偏向性低于其他两个类型种植户。三个组织支持变量对同一类型种植户参与不同价值链技术活动以及不同类型种植户参与同一价值链技术活动的影响具有异质性。因此,针对不同类型价值链技术活动参与特征以及组织支持调节作用提出相应的政策建议。     

A simple,automatic and adaptive bivariate density estimator based on conditional densities

The standard approach to non-parametric bivariate density estimation is to use a kernel density estimator. Practical performance of this estimator is hindered by the fact that the estimator is not adaptive (in the sense that the level of smoothing is not sensitive to local properties of the density). In this paper a simple, automatic and adaptive bivariate density estimator is proposed based on the estimation of marginal and conditional densities. Asymptotic properties of the estimator are examined, and guidance to practical application of the method is given. Application to two examples illustrates the usefulness of the estimator as an exploratory tool, particularly in situations where the local behaviour of the density varies widely. The proposed estimator is also appropriate for use as a pilot estimate for an adaptive kernel estimate, since it is relatively inexpensive to calculate.     

改革开放以来中国经济发展及1997—2010年经济发展预测(三)——中国地区经济发展的政策思路

预测“九五”至2010年中国地区经济发展,分析区域经济发展的两大特征,总结影响地区经济发展差别的基本规律,提出促进中国区域经济协调发展的政策选择。     

Fit and Skill in Employee Selection: Insights from a Study of Headhunters

We draw upon evidence from a qualitative study of headhunters to provide insights into the character and importance of candidate fit and skill for the selection of a broad range of white-collar employees. Headhunters suggest that the fit of a job candidate is assessed at two levels, one corresponding with a general compatibility with organization-level norms, culture, and strategy, the other corresponding more closely with traits and characteristics of the person or persons with whom the job candidate actually interviews. Skill—a factor which is largely neglected by those who tout the importance of fit—also plays an important and independent role in employee selection. Stalls that influence the selection of employees from a pool of candidates tend to be highly specific if not idiosyncratic, and take the form of what headhunters call hot buttons. We conclude by discussing the conceptualization, causes, and implications of fit; we also consider how the importance of fit and hot buttons challenges the explanatory logic of standard accounts of labor-market success.     

空间OLAP 技术研究

针对决策支持系统中空间数据可视化应用趋势,研究基于空间数据仓库的一种决策分析 工具———在线分析处理,通过改进空间数据立方体的物化视图选择方法,并进行了实例分析, 验证该方法的有效性和优越性,更好地解决空间OLAP 响应时间延迟问题. 进而扩展空间OLAP 应用模型和模式,实现更加完备、灵活的空间OLAP 操作功能.     

The Big Five personality factors and team performance: implications for selecting successful product design teams

In the pursuit of faster product development, product design teams are a growing phenomenon in many organizations. In order to be successful, these teams must be composed of people who work well together. However, despite the benefit of selecting the optimal combination of team members, this topic has received little attention. Personality has been identified as a potentially helpful selection variable in the determination of optimal team composition. This study examines the relationships between the ‘Big Five’ personality factors (Conscientiousness, Extraversion, Neuroticism, Agreeableness, and Openness to Experience) and objective team performance for three-member product design teams. In addition to this, the potential incremental contribution of personality to the variance in team performance over that accounted for by established selection measures such as general cognitive ability was investigated. In the short duration of the study, it became apparent that some teams were capable of success, and some were not. Successful teams were characterized by higher levels of general cognitive ability, higher extraversion, higher agreeableness, and lower neuroticism than their unsuccessful counterparts. In successful teams, the heterogeneity of conscientiousness was negatively related to increments in product performance. Implications for the selection of product design teams and future directions for research are discussed.     

Analytical network process for software selection in product development: A case study

Application of software for manufacturing processes is one of the resolutions many enterprises have resorted to in the 21st century. This has been a result of increased complexity of products, globalization, rapid changes in technology and so on. The idea was that application of software especially for product development would increase the competitive advantage of industry nevertheless the irony has been that most of the investment in software has not achieved the expected results. We carry out a case study to introduce a methodology, the analytical network process as a multiattribute strategic decision making approach to help in the selection of appropriate software to suit the product development process of a particular product.     

信息不完全确定的区域产品模糊区间聚类方法

区域产品分类与选择是区域经济发展中最重要和最基础的工作.在产品选择与分类时,需要确定指标权系数和分类阈值等参数,这在实际应用中是比较困难的.针对这种情况,提出了一种信息不完全确定的区域产品模糊区间聚类方法.该方法构建了指标权系数信息不完全确定的最优模糊区间聚类模型,利用遗传算法和改进的FCM算法联合求解所得优化模型,得到指标权系数、最优聚类中心和最优划分,进而确定各产品所属类别.最后将该方法应用于某区域的产品分类和主导产品的确定中,实例计算说明该方法的可行性和有效性.