Isotropic Random Fields with the Von Kármán–Whittle Type Correlation Structure

This article proposes a subclass of stationary Gaussian or elliptically contoured random fields whose covariance functions are isotropic and are the linear combination of the von Kármán–Whittle structure. A particular example of this type of random fields is the so-called spartan random field recently appeared in the applied literature.     

考虑复杂关联情境的城市典型生命线运行风险因素识别方法研究

城市典型生命线以供热、电力、燃气系统为代表,具有公共性强、风险性高、关联性显著的特点。研究城市典型生命线运行风险因素识别问题对于相关部门防范风险具有重要意义,但现实中由多系统、多风险因素以及各类关联形成的复杂关联情境增加了解决该问题的难度。为此,本文首先构建了具有层级网络结构的风险因素识别框架,然后提出了一种考虑复杂关联情境的风险因素识别方法,将各专家针对系统关联和风险因素关联给出的语言评价信息转化为二元语义,并将决策试验与评价实验室（DEMATEL）法和Two-Additive Choquet（TAC）积分算子扩展到二元语义环境,进而实现各类关联的综合集成,从而确定风险因素的排序和归类,便于决策者研判风险根源、明晰风险因素本质。最后,以北京某样区为例验证了所提方法的潜在应用价值,并根据识别结果制定了针对性的风险防范策略,能够为相关部门联调联动开展风险防范提供决策支持。     

从复合句零主语指代看汉英语言思维的差异

和英语零主语指代相比,汉语零主语指代的现象要复杂得多,这种差异很大程度上是由汉英语言的不同思维特点造成的。本文通过意合和形合、主题显著和主语显著、主体思维和客体思维、整合思维和拆分思维四个方面的比较,对复合句零主语的指代所反映的汉英语言思维特点上的差异进行了分析。     

A New Formulation For The Multinomial Selection Problem

The two approaches to a multinomial ranking and selection problem (for selecting the t best cells out of k are combined to form a new apprach. In this new approach there is a preference zone (PZ) and an indifference zone (IZ), and the concept of a correct selection (CS) is defined differentlv in eac of these zones. Lower bounds for the probability of correct selection p(CS) are then guaranteed in each of these zones using a single experiment. The procedure on the ordered frequencies in the cells. The principle tool used to derive expressins for the p(CS). for the expected sample size EN, for the expected subsct size ES and for other probabilities. is the Dirichlet integral (Type 2) which was recent tabulated. These Dirichlet integrals are used to prove that the multiplicative slippage configuratin is leas favorable in the PZ and, for t = l, that the IZ. Numerical calculations are carried out for an illustrative example but extensive tables are not yet avalable

     

A unified approach to minimum variance unbiased estimation of a probability function belonging to an exponential family

The problem of minimum variance unbiased estimation of the probability density function of a random variable belonging to an exponential family is considered. The method of estimation proposed in this paper requires the solution of a certain integral equation. For many probability distributions the solution of this equation is given by a known result in integral transform theory.     

On count time series prediction

We consider the problem of assessing prediction for count time series based on either the Poisson distribution or the negative binomial distribution. By a suitable parametrization we employ both distributions with the same mean. We regress the mean on its past values and the values of the response and after obtaining consistent estimators of the regression parameters, regardless of the response distribution, we employ different criteria to study the prediction problem. We show by simulation and data examples that scoring rules and diagnostic graphs that have been proposed for independent but not identically distributed data can be adapted in the setting of count dependent data.     

Symbolic Itô calculus in AXIOM: An ongoing story

Symbolic Itô calculus refers both to the implementation of Itô calculus in a computer algebra package and to its application. This article reports on progress in the implementation of Itô calculus in the powerful and innovative computer algebra package AXIOM, in the context of a decade of previous implementations and applications. It is shown how the elegant algebraic structure underlying the expressive and effective formalism of Itô calculus can be implemented directly in AXIOM using the package's programmable facilities for strong typing of computational objects. An application is given of the use of the implementation to provide calculations for a new proof, based on stochastic differentials, of the Mardia-Dryden distribution from statistical shape theory.     

DSA系列保护、测控“一体化“系统的设计思想和技术特点

介绍分散式变电站自动化(DSA系列)保护、测控"一体化"系统的设计思想,即分布式系统和面向对象的分散式结构、充分集成并兼顾不同管理模式、可分散安装也可集中组屏的配置方式、充分利用信息资源实现技术创新等.DSA系列具有先进可靠,功能完善,模块化、标准化设计和易于维护、调试等技术特点.该系列较集中的反应了当前保护测控一体化的发展趋势.