Subjective probability and causality assessment

Serious adverse reactions to a drug usually occur too rarely to be identified in the clinical trials required to demonstrate efficacy before the drug can be put on the market. Instead, they are generally first encountered in the uncontrolled world of everyday clinical practice, and the industrial and national regulatory agencies that are responsible for drug safety must rely for their first indications of a possible drug-adverse event connection on case reports submitted to them by practitioners who observe an occurrence of the event in one of their patients taking the drug. A typical situation in the work of these agencies finds a group of experts assembled around a table reviewing a small series of case reports (perhaps as small as one!) that link a particular drug with a particular type of adverse event. The experts want to determine whether, for each case in their series, the available evidence indicates that the drug caused the adverse event to occur. How are they to proceed? This paper outlines an approach to this problem, based on the use of subjective probability.     

灰色聚类法在三峡库区城市江段水质综合评价中的应用

应用灰色聚类法对三峡库区城市江段13个监测断面水质质量进行综合评价,获得较好的结果,能客观反映三峡库区城市江段质的类别及水体实际污染的状况.通过与模糊综合评价方法进行比较,灰色聚类法具有计算简便的优点,是一种较好的评价方法.     

Adaptive bivariate Chebyshev approximation

We propose an adaptive algorithm which extends Chebyshev series approximation to bivariate functions, on domains which are smooth transformations of a square. The method is tested on functions with different degrees of regularity and on domains with various geometries. We show also an application to the fast evaluation of linear and nonlinear bivariate integral transforms. Work supported by the research project CPDA028291 “Efficient approximation methods for nonlocal discrete transforms” of the University of Padova, and by the GNCS-INdAM.     

Interacting environmental influences: Concepts of synergism,antagonism, and superposition

Since an enormous number of different pollutants is usually simultaneously present in a certain environmental area, it must be expected that interactions between these pollutants may occur frequently. Nevertheless, not very much is known about the combined impact of several pollutants and the environmental policy ignores these effects in defining pollution standards and limits just for single pollutants. Moreover, it is not at all clear how these effects should precisely be described. Starting from definitions of interactions between different environmental influences introduced by Ott [7] and one of the present authors [8], new concepts of synergism (and antagonism and superposition) in a deterministic context will be presented. It is analyzed which properties an environmental quality index has to have in order to describe such interactions.     

基于广义熵的虚拟企业合作伙伴遴选综合评价系统

合作伙伴的评价选择是虚拟企业合作关系运行的基础，合作伙伴的业绩对核心企业的影响越来越大。本在广泛调研的基础上，提出包含评价专家自身权重的广义熵综合评价模型，并结合实例开发出计算机进选支持系统，以辅助盟主企业进行决策。     

影响城市地价最优因素组合的选择及权重确定

笔者在城市土地定级估价综合模型[1] 的基础上 ,应用最优回归自变量集的选择方法[2 ] ,得到了影响城市地价最优因素组合的选择方法及权重的确定方法 ,并将其实际应用于山西省古交市的地产评估 ,结果表明 ,该方法比现行方法节省经费且使评估结果更符合实际。     

信息系统安全风险的属性评估方法

首次将属性理论和属性综合评估模型引入信息系统安全风险的评估领域 ,为信息系统安全风险程度的评估提出了一种新方法 ,对于信息系统安全性的动态管理有着积极的意义 .     

新产品设计前端的筛选与评价系统研究

本着重于新产品设计前端的筛选与评价系统研究。设计了若干准则，有社会环境准则、经济成本准则、技术准则、时间准则、价值准则等，对新产品构思进行筛选。运用模糊理论，确定隶属度函数，得到评价矩阵，最终得到综合评价；运用加权评分法，确定评判的各影响因素及其各自所占的权重，给每种构思进行评分，根据最后总得分的多少来评定构思的优劣。最后，阐述了评价系统在设计过程中的重要作用，评价系统贯穿于整个设计过程中。     

Analyzing the Performance of Generalized Hill Climbing Algorithms

Generalized hill climbing algorithms provide a framework to describe and analyze metaheuristics for addressing intractable discrete optimization problems. The performance of such algorithms can be assessed asymptotically, either through convergence results or by comparison to other algorithms. This paper presents necessary and sufficient convergence conditions for generalized hill climbing algorithms. These conditions are shown to be equivalent to necessary and sufficient convergence conditions for simulated annealing when the generalized hill climbing algorithm is restricted to simulated annealing. Performance measures are also introduced that permit generalized hill climbing algorithms to be compared using random restart local search. These results identify a solution landscape parameter based on the basins of attraction for local optima that determines whether simulated annealing or random restart local search is more effective in visiting a global optimum. The implications and limitations of these results are discussed.     

One- and two-phase flow during fluid sampling by a wireline tool

Wireline sampling tools withdraw a few litres of fluid from a permeable formation via a small sink probe pressed against the borehole wall. The aim is to recover, quickly and cheaply, a representative native fluid sample. Unfortunately, the formation in the near wellbore region is invaded by mud filtrate, and withdrawal of nonnative fluid initially is inevitable. It is therefore of interest to estimate the proportion of native fluid in the sample stream, as a function of time.Semi-analytical calculations of one- and two-phase sampling flows are presented, for the special case of constant total fluid mobility in the limits of very deep or very shallow invasion. Both the interaction of the initially cylindrically symmetric invasion profile with the spherically symmetric flow and the capillary shock-forming dynamics of two-phase flow are found to control the character of sample composition variation. The wide variety of sample stream composition histories is displayed.