Bayesian MCMC Mapping of Quantitative Trait Loci in a Half-sib Design: a Graphical Model Perspective

Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example.     

Blocked-Error-R 2: A Conceptually Improved Definition of the Proportion of Explained Variance in Models Containing Loops or Correlated Residuals

Bentler and Raykov (2000, Journal of Applied Psychology 85: 125–131), and Jöreskog (1999a, http://www.ssicentral.com/lisrel/column3.htm, 1999b http://www.ssicentral. com/lisrel/column5.htm) proposed procedures for calculating R ² for dependent variables involved in loops or possessing correlated errors. This article demonstrates that Bentler and Raykov’s procedure can not be routinely interpreted as a “proportion” of explained variance, while Jöreskog’s reduced-form calculation is unnecessarily restrictive. The new blocked-error-R ² (beR ²) uses a minimal hypothetical causal intervention to resolve the variance-partitioning ambiguities created by loops and correlated errors. Hayduk (1996) discussed how stabilising feedback models – models capable of counteracting external perturbations – can result in an acceptable error variance which exceeds the variance of the dependent variable to which that error is attached. For variables included within loops, whether stabilising or not, beR ² provides the same value as Hayduk’s (1996) loop-adjusted-R ². For variables not involved in loops and not displaying correlated residuals, beR ² reports the same value as the traditional regression R ². Thus, beR ² provides a conceptualisation of the proportion of explained variance that spans both recursive and nonrecursive structural equation models. A procedure for calculating beR ² in any SEM program is provided.     

Influence analysis for Poisson inverse Gaussian regression models based on the EM algorithm

For Poisson inverse Gaussian regression models, it is very complicated to obtain the influence measures based on the traditional method, because the associated likelihood function involves intractable expressions, such as the modified Bessel function. In this paper, the EM algorithm is employed as a basis to derive diagnostic measures for the models by treating them as a mixed Poisson regression with the weights from the inverse Gaussian distributions. Several diagnostic measures are obtained in both case-deletion model and local influence analysis, based on the conditional expectation of the complete-data log-likelihood function in the EM algorithm. Two numerical examples are given to illustrate the results.     

企业同质性假设、异质性假设与企业性质

本文通过对企业同质性假设和异质性假设的进一步探讨,认为运用企业同质性假设的抽象方法可以合乎逻辑的解释企业的契约本质和企业契约的"规制或分配性",而企业异质性假设方法的运用可以理解企业的多样性和差异性,从而对企业契约的"生产性"做出令人信服的解释.企业契约理论和企业能力理论在事实上共同构成了一个有关企业性质认识的完整分析框架.     

深圳市环境事件应急处置服务费用定价方法研究

基于深圳环境形势和应急处置服务的特殊性,总结了环境应急处置服务费用的影响因素及其构成要素,初步研究符合深圳实际的环境应急处置服务费用定价方法。深圳市环境应急处置服务费用包含了4大类、9小类的构成要素及数十项具体收费项目,基本涵盖当前环境应急处置服务的主要内容。列明了大部分项目的计价公式和计价单位,对无法详细列明或难以给出具体收费数额的项目,依据共性原则列出了公式和关键参数,确保有效指导费用的计算。     

North–South terms‐of‐trade trends from 1960 to 2006

The composition of exports of developing countries is increasingly dominated by manufactured goods. This has not changed the fact that their major trading partners continue to be the developed countries. In order to properly assess the distribution of gains from trade, there is a pressing need to analyze the movements in the terms of trade of developing countries with respect to the developed ones. A statistical analysis of the North–South terms of trade reveals that the terms of trade have turned against the South since the 1960s. However, the terms‐of‐trade deterioration is neither continuous nor evenly distributed over different country groupings. The existence of a structural break in the mid‐to‐late 1970s together with the greatest adverse terms‐of‐trade movements against the highly indebted and least developed countries attest the discontinuity and unevenness of this process.     

Goal programming: Planning process of tourism organizations

The complex rapidly changing environment faced by tourism organization officials makes tourism planning extremely difficult. Goal programming can aid the tourism planner in appraising the goal attainment potential associated with proposed tourism marketing program alternatives. By changing priorities of goals, budgetary limitations, and organizational constraints, the policy maker can test the effect of changes before they are implemented. By utilizing goal programming, a tourism organization can more systematically evaluate the nature and relative importance of organizational goals, critical constraints affecting the organization and marketing program alternatives.