Entropy Principles in Decision Making Under Risk

This paper considers decision problems where: (1) The exact probability distribution over the states of nature is not precisely known, but certain prior information is available about the possibilities of these outcomes; (2) A prior distribution over the states of nature is known, but new constraint information about the probabilities becomes available. The maximum entropy principle asserts that the probability distribution with maximum entropy, satisfying the prior knowledge, should be used in the decision problem. The minimum cross-entropy principle says that the posterior distribution is the one which minimizes cross-entropy, subject to the new constraint information. The entropy principles have not gone uncriticized, and this literature, together with that justifying the principles, is surveyed. Both principles are illustrated in a number of situations where the distribution is either discrete or continuous. The discrete distribution case with prior interval estimates based on expert opinions is considered in detail.     

Estimation of the Force of Infection from Current Status Data Using Generalized Linear Mixed Models

Based on sero-prevalence data of rubella, mumps in the UK and varicella in Belgium, we show how the force of infection, the age-specific rate at which susceptible individuals contract infection, can be estimated using generalized linear mixed models (McCulloch & Searle, 2001). Modelling the dependency of the force of infection on age by penalized splines, which involve fixed and random effects, allows us to use generalized linear mixed models techniques to estimate both the cumulative probability of being infected before a given age and the force of infection. Moreover, these models permit an automatic selection of the smoothing parameter. The smoothness of the estimated force of infection can be influenced by the number of knots and the degree of the penalized spline used. To determine these, a different number of knots and different degrees are used and the results are compared to establish this sensitivity. Simulations with a different number of knots and polynomial spline bases of different degrees suggest - for estimating the force of infection from serological data - the use of a quadratic penalized spline based on about 10 knots.     

Theory & Methods: Krige,Smooth, Both or Neither?

Both kriging and non-parametric regression smoothing can model a non-stationary regression function with spatially correlated errors. However comparisons have mainly been based on ordinary kriging and smoothing with uncorrelated errors. Ordinary kriging attributes smoothness of the response to spatial autocorrelation whereas non-parametric regression attributes trends to a smooth regression function. For spatial processes it is reasonable to suppose that the response is due to both trend and autocorrelation. This paper reviews methodology for non-parametric regression with autocorrelated errors which is a natural compromise between the two methods. Re-analysis of the one-dimensional stationary spatial data of Laslett (1994) and a clearly non-stationary time series demonstrates the rather surprising result that for these data, ordinary kriging outperforms more computationally intensive models including both universal kriging and correlated splines for spatial prediction. For estimating the regression function, non-parametric regression provides adaptive estimation, but the autocorrelation must be accounted for in selecting the smoothing parameter.     

温度、内能、熵与热力学定律

从热力学定律出定，引入温度、内能、熵的概念，说明了热力学定律是温度、内能、熵的依据，而温度、内能、熵是热力学定律的数学表示及必然结果．     

An EM Algorithm for Smoothing the Self-consistent Estimator of Survival Functions with Interval-censored Data

Interval-censored data arise in a wide variety of application and research areas such as, for example, AIDS studies (Kim et al ., 1993) and cancer research (Finkelstein, 1986; Becker & Melbye, 1991). Peto (1973) proposed a Newton–Raphson algorithm for obtaining a generalized maximum likelihood estimate (GMLE) of the survival function with interval-cen sored observations. Turnbull (1976) proposed a self-consistent algorithm for interval-censored data and obtained the same GMLE. Groeneboom & Wellner (1992) used the convex minorant algorithm for constructing an estimator of the survival function with "case 2" interval-censored data. However, as is known, the GMLE is not uniquely defined on the interval [0, ∞]. In addition, Turnbull's algorithm leads to a self-consistent equation which is not in the form of an integral equation. Large sample properties of the GMLE have not been previously examined because of, we believe, among other things, the lack of such an integral equation. In this paper, we present an EM algorithm for constructing a GMLE on [0, ∞]. The GMLE is expressed as a solution of an integral equation. More recently, with the help of this integral equation, Yu et al . (1997a, b) have shown that the GMLE is consistent and asymptotically normally distributed. An application of the proposed GMLE is presented     

Estimating powers of the generalized variance under the Pitman closeness criterion

For estimating powers of the generalized variance under a multivariate normal distribution with an unknown mean, the inadmissibility of the closest affine equivariant estimator is shown for the Pitman closeness criterion.     

熵权基点决策法在绿色施工评价中的应用

绿色施工是实现建造方式由劳动力密集型向技术密集型、由粗放型向集约型转变的组织方式。保证绿色施工的有效推进,一方面要创新绿色施工技术,另一方面要采取科学的评价方法。在已有文献的基础上,构建了一套科学的绿色施工评价指标体系,并运用熵理论和基点的决策分析方法建立综合评价模型,在一定程度上克服了以往绿色施工评价中的指标主观、测量效果不准确的问题。通过对某工程施工实例分析证明,该方法实用性强,可以应用于工程项目的前期招标方案评价和施工中、后期的施工质量评价。     

文化、熵与乡村自组织演进——基于系统论视角

乡村自组织在形成生产的、资金的和个体利益的有序化整合中,内在地需要一种社团文化上的信任和共同信息范式的基础。这样的文化上的准备,规定了社团成员间的信任关系和互动方式,使得不论是生产各环节上的协作还是资金信用的让渡都以一种较低的成本运行。研究成果表明,通过新乡村建设带动的新文化注入,出现熵减小的趋势。在当代新乡村建设的案例中,无论是小规模的城乡间的生态产品供应,还是跨越十余个村镇的大范围的耕种实验,都能在其中辨别出"合作"的元素。民间经济协作组织形成过程体现了自发性制度演进特征,以及系统的弹性或可恢复性,即在受到干扰后仍能保留或重新获得它原有的状态或构型。     

有关P_B~⊥P_A、P_A~⊥P_B的矩阵等式和秩等式

在M=(A B)中,令A1=P⊥BPA,B1=P⊥APB,利用投影算子理论和矩阵秩方法可以得到关于A1,B1的一些矩阵等式和秩等式.     

跨文化交际视阈下的旅游宣传资料英译研究

旅游宣传资料的英译是译者、作者和国外游客之间的一种跨时空、跨文化交际活动.旅游宣传资料的翻译者必须增强自身的跨文化敏感性,既精通两种语言又熟谙两种文化,最大限度地兼容交际双方的语言习惯、文化心理、交际规约和价值标准差异.本文试以比较中英旅游宣传资料在遣字用词、句式结构、谋篇布局、文本内容等方面的差异为路径,揭示中英两种语言体系所承载的语言习惯、价值观念、思维模式、民族心理、审美情趣等跨文化交际要素的差异,并提出跨文化交际视阈下的旅游宣传资料英译的原则和方法.