神经元输入输出关系及网络计算特性研究

采用区别对待神经元输入变量空间和输出变量空间的新的研究方法探讨神经网络的计算特性。对于输入变量空间的特性,用微分方程定性理论进行研究;而对输出变量空间的特性,则用函数理论和优化理论进行研究,输入变量空间与输出变量空间由神经元的非线性特性所形成的空间映射关系来联系,文中给出了利用这一研究方法得到的神经网络计算理论的一些新结论。     

On the asymptotic normality of functions of uniform spacings

A new proof is given for the asymptotic normality of sum functions of spacings, providing an alternative to the method of Le Cam (1958). The result is obtained under an optimal moment condition. The proof is based on a simple decomposition into a leading term, which is asymptotically normal, and a remainder term, which is shown to be negligible.     

Social structures and economic conduct: Interpreting variations in household energy consumption

The consumption of natural resources is rapidly emerging as a major social problem, and social efforts to control this consumption are guided in part by research that tries to specify the meaning of resources to consumers. This paper compares a sociological perspective with the more widespread economic model of consumption, using data from study of billing systems, sociocultural status, and household energy use in a California apartment complex. The research suggests that the role of marginal price in ordering consumption can be interpreted as a contingent feature of the socially structured relationship between consumption and social status. It also suggests that the utility of a technology is a secondary and emergent product of its use, a fact obscured by the conventional analytic separation of supply and demand or means and ends.     

The Health Risks of Energy Production

Any personal or societal activity, besides bringing us benefits, also carries some risk. Energy production and use are no exceptions. In order to judge these risks, they must be quantified, and the risks of all alternative methods of producing this energy must then be compared among each other. These risks originate in many parts of the energy cycle; they are diverse in character and involve different parts of the population. It is therefore necessary to discriminate between many aspects of risk so that only reasonably comparable categories are compared. The results of a critical analysis of the international risk literature are presented, which are applicable to power production plants as they could be built today in central European countries. This review pays special attention to the possibility of severe accidents occurring, which attract so much attention in our modern societies. It turns out that the health risks of routine nuclear energy production are lower than the risks of other energy options, particularly for the general public. The probability of a severe accident occurring is far higher for all conventional energy options. Only the renewable systems utilizing the energy of the sun and the wind are not susceptible to severe accidents.     

Risk Assessment for Interconnected Electrical Power Grids

Using an analogy with costs, risk is split into a fixed and a variable contribution. Based on this concept, the total risk of an interconnected electrical power grid is minimized. The theoretical foundations of the method are explained and illustrated by model calculations.     

The Indoor Radiological Problem in Perspective

Measures to tighten homes to conserve energy, as are being encouraged and subsidized by federal and state governments, may reduce air infiltration by 20% or more. Standard prudent risk-assessment methodologies predict that, due to increased levels of indoor radon caused by this reduction in ventilation, the added lifetime lung cancer risk to members of the public is of order 200/million people exposed. In situations where the radon source term is unusually high, or extreme reductions in ventilation are made, the added risk can be more than an order of magnitude greater. While these imputed risks are far outside the range that is normally tolerated, no systematic efforts are in progress to mitigate or limit the risk in any way. Furthermore, efforts to determine better the variations in radon source term and the health effects of indoor radon are being deemphasized. The technical background is presented in some detail, and implications with regard to management of risks to the public are discussed.     

Na_2ZnCl_4·3H_2O:Mn~(2+)晶体ZFS参量单轴压力效应的理论解释

利用对角化完全能量矩阵的方法,借助于文献〔5〕提出的新模型,计算了Na_2ZnCl_4·3H_2O:Mn~(2+)晶体零场分裂(zero—field splitting,简称ZFS)参量及其单轴压力行为,计算值与实验值十分吻合。     

平面电流脉冲远区能量衰减特性研究

运用时域矢势积分方程分析了对称结构平面上三角脉冲、多周期正弦脉冲、等腰梯形脉冲、高斯脉冲和电磁导弹实验脉冲等多种不同波形的电流脉冲;讨论了远区轴线上辐射的电磁场。通过比较分析,得到远区辐射能量衰减特性的一般规律和特殊规律。     

略论我国能源节约利用战略

能源相对短缺、资源利用率低下、环境污染持续上升、生物多样性濒危像一道道难解的方程摆在我国政府面前。日本作为能源短缺的国家，在20世纪60-70年代就开始对能源节约利用问题进行研究，其节能政策一直走在世界的前沿。通过对日本节能政策进行介绍，并与我国能源节约政策进行对比分析，总结其经验，无疑可对我国节能政策制定起到借鉴作用。     

关于霍特林法则失效的讨论

本文就霍特林法则的经济学涵义、失败的原因及其对资源可持续利用的重大意义进行了讨论并得出四个相关的重要结论。