卫星通信地球站终端技术的发展

本文介绍了卫星通信地球站终端技术的发展过程,初步论述了新技术应用的环境,为今后研制卫星通信设备提供某些参考。     

Cooperative game with nondeterministic returns

We study a non-traditional cooperative game where returns from coalitions are nondeterministic. The long-standing concept of core can be generalized to reflect players’ contentment with their allocations. It is now imperative to formalize the restrictions, such as those pertaining to information, on allocations. The latter are also at times more conducive to fractional representations. With probabilistic structures added, nondeterministic returns become random variables, utility functions attain risk-attitude connotations, and the timing of players’ allocation resolutions gains significance. Under various conditions for utility functions, we show how various core concepts of the general game can be related to its traditionally defined auxiliaries. These developments help pave the way for our illustrations, within two distinct settings, that players’ increased risk aversion would promote the formation of the grand coalition.     

混沌在数字通信中的应用

我国高校的国际商务英语专业在经历了20多年的办学历程之后,今天面临着从理论的高度进行整顿、提高的任务。本文发出了“加强理论建设,把我国高校的国际商务英语专业发展成为在理论与实践的结合上更为成熟的独立学科”的呼吁,并阐述了作者对有关国际商务英语学科建设的几个重大问题的看法。     

Type space on a purely measurable parameter space

Summary. Several game theoretical topics require the analysis of hierarchical beliefs, particularly in incomplete information situations. For the problem of incomplete information, Harsányi suggested the concept of the type space. Later Mertens and Zamir gave a construction of such a type space under topological assumptions imposed on the parameter space. The topological assumptions were weakened by Heifetz, and by Brandenburger & Dekel. In this paper we show that at very natural assumptions upon the structure of the beliefs, the universal type space does exist. We construct a universal type space, which employs purely a measurable parameter space structure.Received: 12 August 2002, Revised: 1 March 2004, JEL Classification Numbers: C70, C79, D80, D82.Miklós Pintér: The author wishes to thank Péter Tallos, Tamás Solymosi, and an anonymous referee for their suggestions and comments. This work was supported by OTKA grant T046194.     

超宽带穿墙探测雷达的运动目标检测技术

提出了利用低频超宽带(UWB)脉冲信号实现穿墙探测的设想，研究了超宽带穿墙探测雷达(UWB—TWDR)的运动目标回波信号模型，并基于运动目标回波信号的相关性，利用相干叠加原理对多次观测的结果实现运动目标的检测。最后通过具体的穿透混凝土砖块墙壁实测实验验证了上述设想和算法。     

金融风险测量理论的进展

金融风险测量理论已经成为金融理论一个重要组成部分和研究方向,金融风险分析已经从过去定性的分析发展到运用先进数学模型进行定量的分析和研究。本文综述了金融风险测量理论的研究进展。     

风险度量的经济学理性与风险度量方法比较

本文引入风险度量的经济学理性概念:一种风险度量方法为经济学理性的是指,这种方法对风险的度量结果与经济学中理性人对风险的排序结果相一致,采用这种方法度量风险的决策者,其决策结果也是经济学理性的。本文从风险状态下的决策理论出发,论证了在银行监管问题上,经济学理性的风险度量方法需要满足的条件。结合银行资本充足率监管的演进趋势,比较了几种重要的风险度量方法,并提出了一种经济学理性的、符合银行监管需要的风险度量方法。     

Spectral Risk Measures: Properties and Limitations

Spectral risk measures (SRMs) are risk measures that take account of user risk-aversion, but to date there has been little guidance on the choice of utility function underlying them. This paper addresses this issue by examining alternative approaches based on exponential and power utility functions. A number of problems are identified with both types of spectral risk measure. The general lesson is that users of spectral risk measures must be careful to select utility functions that fit the features of the particular problems they are dealing with, and should be especially careful when using power SRMs.

Performance ratio-based coherent risk measure and its application

Utilizing a specific acceptance set, we propose in this paper a general method to construct coherent risk measures called the generalized shortfall risk measure. Besides some existing coherent risk measures, several new types of coherent risk measures can be generated. We investigate the generalized shortfall risk measure’s desirable properties such as consistency with second-order stochastic dominance. By combining the performance evaluation with the risk control, we study in particular the performance ratio-based coherent risk (PRCR) measures, which is a sub-class of generalized shortfall risk measures. The PRCR measures are tractable and have a suitable financial interpretation. Based on the PRCR measure, we establish a portfolio selection model with transaction costs. Empirical results show that the optimal portfolio obtained under the PRCR measure performs much better than the corresponding optimal portfolio obtained under the higher moment coherent risk measure.