Time Inhomogeneous Multiple Volatility Modeling

Price variations at speculative markets exhibit positive autocorrelationand cross correlation. Due to large parameter spaces necessaryfor joint modeling of variances and covariances, multivariateparametric volatility models become easily intractable in practice.We propose an adaptive procedure that identifies periods ofsecond-order homogeneity for each moment in time. To overcomethe high dimensionality of the problem we transform the multivariateseries into a set of univariate processes. We discuss thoroughlythe implementation of the adaptive technique. Theoretical andMonte Carlo results are given. We provide two applications ofthe new method. For a bivariate exchange rate series we comparethe multivariate GARCH approach with our method and find thelatter to be more in line with the underlying assumption ofindependently distributed innovations. Analyzing a 23-dimensionalvector of asset returns we underscore the case for adaptivemodeling in high-dimensional systems.     

我国企业大学存在的问题及对策

目前国内一些企业有了企业大学,但在筹建和发展过程中还存在许多问题。本文通过分析问题存在的原因,提出了相应的对策以提高我国企业大学的整体水平。     

对科学发展观指导下的高校思想政治教育工作的探讨

科学发展观是推进我国经济社会全面发展的指导思想,也是加强和改进大学生思想政治教育的指导方针。本文通过分析高校思想政治教育存在的普遍问题,提出了在科学发展观指导下的思想政治教育工作的新思路,新途径。     

区域主导产业发展中的地方政府行为研究

地方政府的活动范围应根据市场发挥作用的程度、社会自治的能力加以界定,更好地发挥市场的作用,优化市场经济运行的环境应是政府行为的着眼点。从地方政府官员的意识、赶超愿望、获得新闻界的关注程度等角度探讨地方政府的行为诱导机制,阐明地方政府财政能力、协调能力等方面是导致区域主导产业畸型增长的内因,提出改变地方政府行政模式,是实现地方政府目标与区域主导产业可持续发展的关键所在。     

Awareness of Distributed Denial of Service Attacks' Dangers: Role of Internet Pricing Mechanisms

Denial of Service (DoS) attacks consist of overwhelming a server, a network or a Web site in order to paralyze its normal activity. The additional parameter in Distributed Denial of Service (DdoS) attacks is the distributing strategy. It means that DDoS attacks do not come from a single computer but stem from all accessible channels and servers. Consequences are multiple, ranging from system errors, temporary inability to access the Web site for normal users to challenging the actual reliability of the Internet. Despite this, Internet users show carelessness. The explanation lies in the specificities of DDoS attacks. We explore possibilities to raise users' awareness about the actual amplitude of problems caused by DDoS attacks. We suggest a careful examination of Internet pricing mechanisms and switching from flat to usage-constraining pricing schemes.     

A comparison of several approximations to the power function of the likelihood ratio test in covariance structure analysis*

In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from H_o the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.     

Stability and Segregation in Group Formation

This paper presents a model of group formation based on the assumption that individuals prefer to associate with people similar to them. It is shown that, in general, if the number of groups that can be formed is bounded, then a stable partition of the society into groups may not exist. (A partition is defined as stable if none of the individuals would prefer be in a different group than the one he is in.) However, if individuals' characteristics are one-dimensional, then a stable partition always exists. We give sufficient conditions for stable partitions to be segregating (in the sense that, for example, low-characteristic individuals are in one group and high-characteristic ones are in another) and Pareto efficient. In addition, we propose a dynamic model of individual myopic behavior describing the evolution of group formation to an eventual stable, segregating, and Pareto efficient partition. Journal of Economic Literature Classification Numbers: C72, H41.     

Management and rational utilization of sports resources in university town

Serving an important condition for supporting sports teaching and research in universities and colleges, sports resources in universities and colleges should be rationally allocated and utilized in a comprehensive manner. Literature data method, survey method, on-the-spot investigation method, interviewing and statistical method are adopted to conduct in-depth research on the current sports resources in universities and colleges. In an all-round way with focusing on rational utilization, multi-tier development and resources sharing, based on domestic and foreign researches and advance experience, it takes universities and colleges in Tianjin as objects of study to bring forward the feasible, efficient, rational and suitable mode of comprehensive development, utilization and sports resources sharing, and the method of resources allocation.     

《笨花》与《棉花垛》乡土叙述的比较——兼及对《铁凝的<笨花>批判》的批判

《笨花》因为和作者早年的《棉花垛》有相似之处而受人非议。《笨花》以乡土叙述的方式描绘了河北农村的风土人情,但是《笨花》中还混杂了多种西方话语,即宗教、女性话语和民族解放话语,这些与乡土社会本应是相抵牾的。然而作者为了塑造乡土社会的和谐风貌,通过对各种话语的挪移,而使它们与乡土叙述的冲突彻底消解,造成了文本张力的缺失。