On Locating and Characterizing Parameter Variation by the Mosumsq Test Statistic

In modelling a system structure it is often important to test the constancy of the structural parameters. If the hypothesis of constant parameters is rejected we wish to characterize the parameter variation. In this paper we examine the usefulness of the MOSUMSQ test statistics for locating and characterizing the parameter variation in linear regression models. The means and the variances of the test statistics are given for non-random parameter variation. The observed path of the MOSUMSQ test statistics provides valuable knowledge about the time of the onset of the parameter change and whether it is instantaneous or gradual.     

Bayesian estimation of multidimensional item response theory model using gibbs sampling

We propose Bayesian parameter estimation in a multidimensional item response theory model using the Gibbs sampling algorithm. We apply this approach to dichotomous responses to a questionnaire on sleep quality. The analysis helps determine the underlying dimensions.     

Improved likelihood-based inference for the stationary AR(2) model

An improved likelihood-based method based on Fraser et al. (1999) is proposed in this paper to test the significance of the second lag of the stationary AR(2) model. Compared with the test proposed by Fan and Yao (2003) and the signed log-likelihood ratio test, the proposed method has remarkable accuracy. Simulation studies are performed to illustrate the accuracy of the proposed method. Application of the proposed method on historical data is presented to demonstrate the implementation of this method. Furthermore, the method can be extended to the general AR(p) model.     

饱和粘土蠕变特性研究及参数确定

将两种弹 粘弹性模型（Burgers和H 2K模型）的一维蠕变方程，转换成三维状态下的应力 应变 时间关系，分别推导出常应力下两种模型的轴向应变随时间变化的方程。采用分级加载法进行室内长期单轴压缩蠕变试验，结合两种模型三维应力状态的轴向应变表达式，对试验结果进行拟合，得出相应模型的本构参数。试验结果表明：饱和粘土在新增荷载作用下2~3　d变形趋于稳定，Burgers模型和H 2K模型均能较好地模拟饱和粘土的衰减蠕变过程；而H 2K模型能更好地模拟土样在常应力作用下的蠕变特性。     

中国小说理论与批评的哲性因子

“依经论文”、“依道论文”在中国古代小说评论中是一个重要的角度和原则,这些论述都在强调小说的思想性即哲性因子。那么,这是否就意味着中国古代文化人对小说就不采取“依史论文”的视角和原则呢?当然不是。余虹先生以及持相同见解的先生的观点是有大量史料为基础的,我们之所以特别突出地强调中国古代小说理论与批评中的哲性因子,是意在与余虹先生的见解构成互补,以防止偏误和片面的认识。     

深亚微米MOS器件模型BSIM2及其参数提取

详细分析了适用于ＶＬＳＩ／ＵＬＳＩ设计的深亚微米ＢＳＩＭ２ＭＯＳ器件模型，并在深入讨论短沟道ＭＯＳ器件物理效应的基础上，对沟道长１μｍ栅氧化层厚度２５ｎｍ的ｎＭＯＳＦＥＴ进行了测试和ＢＳＩＭ２模型参数的提取，且对结果进行了分析和讨论。结果表明，ＢＳＩＭ２具有精确、参数易提取、计算速度快的特点，是ＶＬＳＩ／ＵＬＳＩ模拟设计的重要工具之一。     

泡沫塑料衬垫缓冲性能11参数模型及其参数识别

提出了 11参数性粘弹塑性模型 ,反映了泡沫塑料衬垫缓冲性能的特征 .     

Variability in Physical Constant Parameter Values from Standard Data Sources and the Implication of This Variability for Risk Analysis

Physical property values are used in environmental risk assessments to estimate media and risk-based concentrations. However, considerable variability has recently been reported with such values. To evaluate potential variability in physical parameter values supporting a variety of regulatory programs, eight data sources were chosen for evaluation, and chemicals appearing in at least four sources were selected. There were 755 chemicals chosen. In addition, chemicals in seven environmentally important subgroups were also identified for evaluation. Nine parameters were selected for analysis-molecular weight (MolWt), melting point (MeltPt), boiling point (BoilPt), vapor pressure (VP), water solubility (AqSOL), Henry's law constant (HLC), octanol-water partition coefficient (Kow), and diffusion coefficients in air (Dair) and water (Dwater). Results show that while 71% of constituents had equal MolWts across data sources, <3% of the constituents had equivalent parameter values across data sources for AqSOL, VP, or HLC. Considerable dissimilarity between certain sources was also observed. Furthermore, measures of dispersion showed considerable variation in data sets for Kow, VP, AqSOL, and HLC compared to measures for MolWt, MeltPt, BoilPt, or Dwater. The magnitude of the observed variability was also noteworthy. For example, the 95th percentile ratio of maximum/minimum parameter values ranged from 1.0 for MolWt to well over 1.0E + 06 for VP, and HLC. Risk and exposure metrics also varied by similar magnitudes. Results with environmentally important subgroups were similar. These results show that there is considerable variability in physical parameter values from standard sources, and that the observed variability could affect potential risk estimates and perhaps risk management decisions.     

技术进步计算和经济发展研究中的势分析模型

柯布—道格拉斯生产函数(CD生产函数)是技术进步测算和经济分析的重要函数。势分析理论和方法在CD生产函数的基础上对技术进步指标的测算方法进行了改进,使之能提供更多更合理的有用信息。边际经济参数、全要素生产率和科技进步指标都是经济运行分析中的一些重要经济指标,势分析方法使之和宏观经济发展研究统一起来。     

平行带状线间加孔栅的抗耦合干扰技术研究

针对平行带状线间的耦合问题,比较了平行带状线间不加孔栅和加孔栅的耦合干扰问题,研究了平行带状线间距不同时加不同孔栅结构的抗耦合干扰情况,分析了孔径与反射损耗的关系。通过计算与仿真,得到了一种新型的孔栅结构,有效地抑制了平行带状线间的耦合干扰。