Tests and Confidence Intervals for an Extended Variance Component Using the Modified Likelihood Ratio Statistic

Abstract.  The large deviation modified likelihood ratio statistic is studied for testing a variance component equal to a specified value. Formulas are presented in the general balanced case, whereas in the unbalanced case only the one-way random effects model is studied. Simulation studies are presented, showing that the normal approximation to the large deviation modified likelihood ratio statistic gives confidence intervals for variance components with coverage probabilities very close to the nominal confidence coefficient.     

Approximate optimal allocation in repeated sampling from a finite population

Samples of size n are drawn from a finite population on each of two occasions. On the first occasion a variate x is measured, and on the second a variate y. In estimating the population mean of y, the variance of the best linear unbiased combination of means for matched and unmatched samples is itself minimized, with respect to the sampling design on the second occasion, by a certain degree of matching. This optimal allocation depends on the population correlation coefficient, which previous authors have assumed known. We estimate the correlation from an initial matched sample, then an approximately optimal allocation is completed and an estimator formed which, under a bivariate normal superpopulation model, has model expected mean square error equal, apart from an error of order n^-2, to the minimum enjoyed by any linear, unbiased estimator.     

关于我国林产品安全问题的思考

产品安全问题是我国经济领域的热点问题。本文讨论了林产品安全的概念与内涵，认为林产品安全既包括质量安全又包括生态安全。在此基础上，文章论述了当前我国林产品质量安全与生态安全的现状及发展动向。最后，文章得出了我国林产品总体上尚处于不安全状态的初步结论。     

Random Bernstein Polynomials

Random Bernstein polynomials which are also probability distribution functions on the closed unit interval are studied. The probability law of a Bernstein polynomial so defined provides a novel prior on the space of distribution functions on [0, 1] which has full support and can easily select absolutely continuous distribution functions with a continuous and smooth derivative. In particular, the Bernstein polynomial which approximates a Dirichlet process is studied. This may be of interest in Bayesian non-parametric inference. In the second part of the paper, we study the posterior from a "Bernstein–Dirichlet" prior and suggest a hybrid Monte Carlo approximation of it. The proposed algorithm has some aspects of novelty since the problem under examination has a "changing dimension" parameter space.     

凝聚随机算子的一个不动点定理

利用拓扑度的基本性质，给出了凝聚随机算子的一个不动点定理，由此推广了Altman定理，为进一步研究随机算子方程解的存在唯一性及解的近似方法提供了一个有力的工具。     

森林旅游业投资利率确定研究

通过对森林旅游业投资利率的本质分析,探讨了森林旅游业投资利率选取的基本原则和影响因素。根据资金时间价值的基本原理与森林旅游业实际统计数据,提出了我国目前森林旅游业投资利率的具体范围和操作建议,为森林旅游投资的科学决策提供了参考依据。     

旬河中上游地区森林种子植物区系分析

对旬河中上游地区森林的植物区系进行了分析，指出该区种子植物区系比较丰富，区系的地理成分复杂，温带成分起主导作用．     

Urban tree cover: an ecological perspective

Analysis of urban tree cover is generally limited to inventories of tree structure and composition on public lands. This approach provided valuable information for resource management. However, it does not account for all tree cover within an urban landscape, thus providing insufficient information on ecological patterns and processes. We propose evaluating tree cover for an entire urban area that is based on patch dynamics. Treed patches are classified by their origin, structure, and management intensity. A patch approach enables ecologists to evaluate ecological patterns and processes for the entire urban landscape and to examine how social patterns influence these ecological patterns and processes.     

AN ALGORITHMIC APPROACH TO BAYESIAN LINEAR MODEL CALCULATIONS

A framework is described for organizing and understanding the computations necessary to obtain the posterior mean of a vector of linear effects in a normal linear model, conditional on the parameters that determine covariance structure. The approach has two major uses; firstly, as a pedagogical tool in the derivation of formulae, and secondly, as a practical tool for developing computational strategies without needing complicated matrix formulae that are often unwieldy in complex hierarchical models. The proposed technique is based upon symbolic application of the sweep operator SWP to an appropriate tableau of means and covariances. The method is illustrated with standard linear model specifications, including the so-called mixed model, with both fixed and random effects.     

森林对人类生存的重要影响

森林与人类生存密切相关，森林为人类提供生物资源及适宜的生态环境．人类应该停止毁坏森林并自觉保护森林，实施可持续发展战略．