地方高等教育收益的若干问题探讨

地方高等教育的收益与本地区经济水平的发展成正比；高等教育的受益者首先是受教育者个人；可以从高等教育提高劳动生产率中来计算高等教育的收益；应该以科技为中介来研究高等教育的收益；可以从受高等教育者的职业优势上来发现高等教育的收益；可以从人才的流动或者人才市场的变化中发现高等教育的收益。     

On the Convergence of the Monte Carlo Maximum Likelihood Method for Latent Variable Models

While much used in practice, latent variable models raise challenging estimation problems due to the intractability of their likelihood. Monte Carlo maximum likelihood (MCML), as proposed by Geyer & Thompson (1992 ), is a simulation-based approach to maximum likelihood approximation applicable to general latent variable models. MCML can be described as an importance sampling method in which the likelihood ratio is approximated by Monte Carlo averages of importance ratios simulated from the complete data model corresponding to an arbitrary value of the unknown parameter. This paper studies the asymptotic (in the number of observations) performance of the MCML method in the case of latent variable models with independent observations. This is in contrast with previous works on the same topic which only considered conditional convergence to the maximum likelihood estimator, for a fixed set of observations. A first important result is that when is fixed, the MCML method can only be consistent if the number of simulations grows exponentially fast with the number of observations. If on the other hand, is obtained from a consistent sequence of estimates of the unknown parameter, then the requirements on the number of simulations are shown to be much weaker.     

Modelling daily multivariate pollutant data at multiple sites

Summary. This paper considers the spatiotemporal modelling of four pollutants measured daily at eight monitoring sites in London over a 4-year period. Such multiple-pollutant data sets measured over time at multiple sites within a region of interest are typical. Here, the modelling was carried out to provide the exposure for a study investigating the health effects of air pollution. Alternative objectives include the design problem of the positioning of a new monitoring site, or for regulatory purposes to determine whether environmental standards are being met. In general, analyses are hampered by missing data due, for example, to a particular pollutant not being measured at a site, a monitor being inactive by design (e.g. a 6-day monitoring schedule) or because of an unreliable or faulty monitor. Data of this type are modelled here within a dynamic linear modelling framework, in which the dependences across time, space and pollutants are exploited. Throughout the approach is Bayesian, with implementation via Markov chain Monte Carlo sampling.     

纪昀的西域谪戍生涯及《阅微草堂笔记》反映西域风土人情的特点

乾隆三十三年 ,纪昀因为“漏言”被谪贬至西域乌鲁木齐。与古代其他谪贬文人所不同的是 ,他并未完全沉浸于穷愁怨艾的情绪中 ,而是以积极乐观的人生态度面对现实。他的《乌鲁木齐杂诗》及《阅微草堂笔记》多方面地展示了西域的风土人情。但两者在内容及视角上有所不同 ,《乌鲁木齐杂诗》以丰富见长 ,但多粉饰之意 ;《阅微草堂笔记》以深刻取胜 ,真实而颇见其洞察力     

Computing maximum likelihood estimates from type II doubly censored exponential data

It is well-known that, under Type II double censoring, the maximum likelihood (ML) estimators of the location and scale parameters, θ and δ, of a twoparameter exponential distribution are linear functions of the order statistics. In contrast, when θ is known, theML estimator of δ does not admit a closed form expression. It is shown, however, that theML estimator of the scale parameter exists and is unique. Moreover, it has good large-sample properties. In addition, sharp lower and upper bounds for this estimator are provided, which can serve as starting points for iterative interpolation methods such as regula falsi. Explicit expressions for the expected Fisher information and Cramér-Rao lower bound are also derived. In the Bayesian context, assuming an inverted gamma prior on δ, the uniqueness, boundedness and asymptotics of the highest posterior density estimator of δ can be deduced in a similar way. Finally, an illustrative example is included.     

善治理论与中国地方治理

地方治理意味着地方政府从中央一体化的垂直结构下抽身,确立自身的独立地位与利益;同时,它也表征着民间社会力量的成长并逐步参与地方公共事务,成为地方治理中重要的参与性力量。在此意义上,善治理论提供了具有借鉴意义的理论框架和分析范式。但是,处于转型期的中国社会,在用善治理论观照中国地方治理时,其前提和基础条件的具备与否是受到质疑的,从而,这一分析框架的适用性也是有限的。     

城市房地产开发项目土地费用估算原理

我国城市房地产开发项目土地费用的政策灵活性和地方特殊性很强 ,它的正确估算的前提是估算原理科学。文章以马克思的土地经济学说为指导 ,借鉴发达国家的土地管理经验 ,从我国城市房地产业发展的需要出发 ,对我国城市房地产开发项目的土地使用费、征地拆迁费、场地开发费、土地税收和管理费的估算原理进行了全面深入的探讨     

英汉句法的比较和转换

英汉句法存在三种最基本的差异 ,即树型结构和线型结构、形合法和意合法以及句子界线的差异。在此基础上 ,着重介绍英汉互译过程中的三种转换方法     

增长曲线模型非齐次线性估计的可容许性

讨论增长曲线模型Y =X1BX2 +ε中回归矩阵B的函数C1BC2 的估计L1YL2 +A ,在矩阵损失 (LT2 L1)Y +A - (ST2 XT2 S1X1)B (LT2 L1)Y +A - (ST2 XT2 S1X1)B T 下 ,我们得到了非齐次线性估计L1YL2 +A在非齐次线性估计类Г ={L1YL2 +A|L1:t×p ,L2 ;n×n ,A :t×s均为已知实阵 }中可容许的充要条件 :L1YL2在Г0 ={L1YL2 |L1:t×p ,L2 :n×s均为已知实阵 }中容许且当LT2 XT2 L1X1=ST2 XT2 S1X1时有A =0。     

Bayesian analysis of mixture modelling using the multivariate t distribution

A finite mixture model using the multivariate t distribution has been shown as a robust extension of normal mixtures. In this paper, we present a Bayesian approach for inference about parameters of t-mixture models. The specifications of prior distributions are weakly informative to avoid causing nonintegrable posterior distributions. We present two efficient EM-type algorithms for computing the joint posterior mode with the observed data and an incomplete future vector as the sample. Markov chain Monte Carlo sampling schemes are also developed to obtain the target posterior distribution of parameters. The advantages of Bayesian approach over the maximum likelihood method are demonstrated via a set of real data.