Critical indicators for assessing the contribution of infrastructure projects to coordinated urban-rural development in China

It is widely recognized that the coordinated development between urban and rural areas can not only narrow gaps in infrastructure between urban and rural areas, promote balanced development in rural areas in terms of society, economy and environment, but is also an effective way to address issues facing agriculture, rural areas and farmers. In line with this, development of infrastructure projects has been an important means for promoting coordinated urban-rural development in developing countries (such as China). However, there is a lack of indicators that can be used to assess the contribution of infrastructure projects to coordinated urban-rural development. This paper thus attempts to present a set of critical indicators for evaluating the contribution of infrastructure projects to coordinated urban-rural development in the particular context of Chongqing, Western China.First, a list of optional indicators that are with potential for assessing the contribution of infrastructure projects to coordinated urban-rural development is presented based on examination on related project feasibility reports, official reports and literature. Then 42 indicators are identified from the optional list through a questionnaire survey. By using the data collected, the relative level of significance of each indicator is derived. Finally, an indicator system consisting of 19 critical indicators is established based on results of principle component analysis. The applicability and significance of the identified indicators for assessing the contribution of infrastructure projects to coordinated urban-rural development are discussed as well.     

Characterization of singular balanced fractional sm factorial designs derivable from balanced arrays with maximum number of constraints

An upper bound on the maximum number of constraints for s-symbol balanced arrays is derived. It is shown that balanced fractional s^m factorial designs derived from some balanced arrays with the maximum possible number of constraints become singular.     

比较优势动态递减概率模型及检验

在比较优势的持续时间是随机变量的条件下,文章运用不确定性数学方法和规范方法,推出了比较优势递减定理,认为比较优势会随着时间增加而递减,具有发散效应,即比较优势不会被锁定.推出的比较优势“无记忆性”定理表明,各国遵循比较优势发展国际贸易是正确的,国际贸易会让各个国家自动寻找到适合本国的比较优势.通过定义比较优势逆转概率,运用实证方法进行研究,研究表明比较优势基本符合比较优势递减定理和“无记忆性”定理内容,认为中国传统劳动密集型优势在逐渐减小,产业结构调整非常成功,逐渐拥有资本密集型优势和技术密集型优势,产业结构越来越合理.     

Interval-valued data regression using partial linear model

Semi-parametric modelling of interval-valued data is of great practical importance, as exampled by applications in economic and financial data analysis. We propose a flexible semi-parametric modelling of interval-valued data by integrating the partial linear regression model based on the Center & Range method, and investigate its estimation procedure. Furthermore, we introduce a test statistic that allows one to decide between a parametric linear model and a semi-parametric model, and approximate its null asymptotic distribution based on wild Bootstrap method to obtain the critical values. Extensive simulation studies are carried out to evaluate the performance of the proposed methodology and the new test. Moreover, several empirical data sets are analysed to document its practical applications.     

稳健学生t回归模型变点估计的Gibbs抽样算法

文章讨论了用学生t线性回归模型估计回归系数变点位置的稳健Gibbs抽样算法.利用学生t分布的正态尺度混合表示,得到各参数的满条件后验分布,通过对满条件分布抽取样本,得到变点位置及其他参数的贝叶斯估计.模拟显示该算法能有效地估计变点位置,并且当数据呈现重尾现象时,该模型较正态变点模型要稳健.     

Construction of Confidence Intervals for the IVIean of a Population Containing Many Zero Values

The likelihood ratio method is used to construct a confidence interval for a population mean when sampling from a population with certain characteristics found in many applications, such as auditing. Specifically, a sample taken from this type of population usually consists of a very large number of zero values, plus a small number of nonzero values that follow some continuous distribution. In this situation, the traditional confidence interval constructed for the population mean is known to be unreliable. This article derives confidence intervals based on the likelihood-ratio-test approach by assuming (1) a normal distribution (normal algorithm) and (2) an exponential distribution (exponential algorithm). Because the error population distribution is usually unknown, it is important to study the robustness of the proposed procedures. We perform an extensive simulation study to compare the percentage of confidence intervals containing the true population mean using the two proposed algorithms with the percentage obtained from the traditional method based on the central limit theorem. It is shown that the normal algorithm is the most robust procedure against many different distributional error assumptions.     

On concurrence of several linear regressions and applications to problems of enzyme kinetics

In comparing several regressions E(y_ij) =α_i + β_ix_ij i = 1, 2, ..., k, j = 1,2, ..., n_i, researchers are generally interested in the following five problems: whether they have (1) equal slope, (2) equal intercept, (3) coincidence, (4) common intersection on X-axis, and (5) common intersection on (X,Y) - plane. Problems (1) - (3) can be put into the framework of the general linear hypothesis and the F-test can be used. However, problems (4) and (5) cannot be put into the general linear hypothesis because they are ratios of parameters. Hence, in this paper we consider the generalized likelihood ratio test for hypothesis testing. An application to an enzyme kinetics problem in Aniline Metabolism is demonstrated     

On the maximum number of constraints for s-symbol balanced arrays of strength t

Several upper bounds on the maximum number of constraints for s-symbol balanced arrays of strength t are given. Some bounds derived here include the results obtained by Rafter and Seiden (1974), Chopra (1982, 1983) and Saha, Mukerjee and Kageyama (1983).     

The effects of individually varying times of observations on growth parameter estimations in piecewise growth model

When using latent growth modeling (LGM), researchers often restrict the factor loadings, while the multilevel modeling (MLM) treats time as a metric variable. However, when individually varying times of observations are concerned in the longitudinal studies, the use of specified loadings would lead to inaccurate estimation. Based on piecewise growth modeling (PGM), this simulation study showed that (i) individually varying times of observations with larger boundaries got worse estimates and model fits when LGM was used; (ii) estimating the PGM across all the simulation situations was robust within MLM, whereas LGM got identically equal estimation with MLM only in the case of time boundaries of ±1 month or shorter; (iii) larger change of slope in piecewise modeling indicated better estimation.     

论保护知识产权对信息资源共享的影响

在知识经济环境下 ,信息资源共享是提高整个社会信息资源获知能力与利用率的关键。保护知识产权就是保护知识生产者生产知识的动力 ,就是保护资源共享的源泉。它可以极大地促进知识资源的生产和有序利用。同时 ,保护知识产权又将在一定程度上限制和约束资源共享。因此 ,保护知识产权 ,充分发挥资源共享的功能 ,需要加强知识产权保护的立法、执法及宣传 ,实现保护知识产权与资源共享的有机结合