平面热源法瞬态测量材料热物性的研究

简述了平面热源法瞬态测量材料热物理性质的基本原理,分析了快速法、脉冲法测量存在的问题。在此基础上,研究了材料热物性瞬态自动测量技术。测量实践表明:瞬态自动测量仪测量准确可靠,与用防护热板法测量的结果也符合得很好。     

中日石油进口贸易博弈分析及对策研究

对于同为世界上重要的石油消费国和进口国的中国和日本两国而言,获得稳定的石油进口保障对于国家安全具有举足轻重的作用.然而,两国在石油进口来源上大部分重叠,并存在类似的石油安全战略.获得地缘上临近的俄罗斯所拥有的丰富油气资源是中日两国获得石油供给的最佳选择.文章在进行相关分析与博弈分析的基础上,指出中日石油进口贸易之间的博弈并非一个静态的零和博弈,而是一个动态的、不断变化发展的博弈过程,同时提出中国石油进口贸易的相关政策建议.     

农业生产风险管理策略的研究

农业生产经营风险管理所涉及的风险因素很多,主要有:(1)单产变化;(2)价格变化;(3)新技术或新知识变化;(4)农业投入水平变化;(5)政府政策变化;(6)法律变化;(7)消费者偏好变化,等等。通过权衡风险和收益,采用适宜的管理策略来规避风险,提高收益,形成了一系列非确定性关系下的风险决策方法。联系河北省20世纪90年代以来农业生产的实际情况,探讨了各种主要的规避或减少农业生产风险的方法和策略,如利用偏相关系数最小的方法选择稳定的生产项目;采用多种经营以分散风险的组合策略;提高农业生产经营灵活性的诸多措施;利用二次规划以建立风险最小而又能保证一定收入水平的最优规划方法等。     

农机服务发展与粮食生产效率研究:2004—2016——基于变系数随机前沿分析

采用“两步法”研究了农机服务发展与中国粮食生产效率的关系.基于2004-2016年全国31省份粮食生产投入产出的面板数据,利用变系数随机前沿分析方法测算了中国粮食生产的技术变化、技术效率以及全要素生产率,然后构建农机服务发展影响粮食生产效率的OLS回归模型.结果表明:(1)31省份粮食生产的投入要素产出弹性和技术效率存在明显差异,2008年粮食技术变化最为明显,粮食全要素生产率的增长在2008年高达5%.(2)农机服务在2008年以后对粮食全要素生产率的增长具有显著的促进作用,农机服务对粮食TFP的作用存在一定的滞后效应.(3)农机服务发展与劳动产出弹性具有替代关系,与化肥和机械产出弹性具有互补关系.在三大粮食作物中,小麦机械化程度最高,水稻和玉米的机械化程度还有待提升.     

Asymptotic distribution of regression correlation coefficient for Poisson regression model

This study treats an asymptotic distribution for measures of predictive power for generalized linear models (GLMs). We focus on the regression correlation coefficient (RCC) that is one of the measures of predictive power. The RCC, proposed by Zheng and Agresti is a population value and a generalization of the population value for the coefficient of determination. Therefore, the RCC is easy to interpret and familiar. Recently, Takahashi and Kurosawa provided an explicit form of the RCC and proposed a new RCC estimator for a Poisson regression model. They also showed the validity of the new estimator compared with other estimators. This study discusses the new statistical properties of the RCC for the Poisson regression model. Furthermore, we show an asymptotic normality of the RCC estimator.     

Stochastic correlation coefficient ensembles for variable selection

In this paper, we propose a novel Max-Relevance and Min-Common-Redundancy criterion for variable selection in linear models. Considering that the ensemble approach for variable selection has been proven to be quite effective in linear regression models, we construct a variable selection ensemble (VSE) by combining the presented stochastic correlation coefficient algorithm with a stochastic stepwise algorithm. We conduct extensive experimental comparison of our algorithm and other methods using two simulation studies and four real-life data sets. The results confirm that the proposed VSE leads to promising improvement on variable selection and regression accuracy.     

Pooled Cross-Sectional and Time Series Data: A Survey of Current Statistical Methodology

A data base that provides a multivariate statistical history for each of a number of individual entities is called a pooled cross-sectional and time series data base in the econometrics literature. In marketing and survey literature the terms panel data or longitudinal data are often used. In management science a convenient term might be management data base. Such a data base provides a particularly rich environment for statistical analysis. This article reviews methods for estimating multivariate relationships particular to each individual entity and for summarizing these relationships for a number of individuals. Inference to a larger population when the data base is viewed as a sample is also considered.     

Tables of the exact quantiles of the top-down correlation coefficient for n - 3(1)14

Iman and Connver (1985, 1987) have suggested the top-down correlation coefficient as a measure of association when n objects are ranked by two or more independent sources and interest centers primarily on agreement in the top rankings, with disagreements on items at the bottom of the rankings being of little or no importance. The top-down correlation coefficient results from computing the ordinary Pearson correlation coefficient on Savage scores. Quantiles of the exact distribution of the top-down correlation coefficient based on the assumption of independent rankings are provided for n = 3(1)14.     

Mathematical forms of the distribution of the product of two normal variables

This paper finds the mathematical forms of the distribution of the product where x and x follow a bivariate normal distribution In this paper the distribution when PT0 is expressed as an integral, a new, fundamental result. From this general form, six different cases can be distinguished depending on what is known about the parameters and p. The special cases are Aroian $year:1959 and (6) Additionally, we prove that if and as the distribution of the product approaches the Type III distribution. When p=0# Aroian $year:1959 and Aroian and Meeker $year:1977, give tables for various values of 6., 6 . The results in this paper will be used to provide brief tables for p^O in a separate paper     

Generalized RCINAR(1) Process with Signed Thinning Operator

A generalized random coefficient first-order integer-valued autoregressive process with signed thinning operator is introduced, this kind of process is appropriate for modeling negative integer-valued time series. Strict stationarity and ergodicity of process are established. Estimators of the parameters of interest are derived and their properties are studied via simulation. At last, we use bootstrap method in the real data analysis.