面向安全硬约束的煤矿生产物流效率优化研究

在保证安全生产前提下实现效率最大化是煤炭生产企业亟需解决的现实问题。本文结合煤矿生产物流系统的复杂性特征,首先从人员素质、机械装备、环境改善、安全管理、应急救援等方面确定了煤矿生产物流的安全投入指标,运用响应曲面法分析了安全指标与安全水平间的作用关系,确定了煤矿生产物流安全硬约束条件;然后以效率最大化为目标函数、安全目标和资源投入为约束条件,构建了煤矿生产物流效率优化模型;最后通过实例验证了模型的有效性及适用性,为安全生产前提下实现资源优化配置,提高煤矿生产物流效率提供了科学依据。     

离散事件与外贸序列结构变化——基于中国2000年以来月度数据的实证检验

重大离散事件可能引致进出口贸易时间序列发生结构变化。通过蒙特卡罗模拟得到既定样本结构变化的单边检验值,对2000年以来中国进、出口额月度序列进行结构变化检验,结果显示:2001年加入WTO、2002年爆发SARS疫情、2005年人民币汇率形成机制改革、2010年CAFTA正式启动等离散事件没有使中国进出口贸易产生结构变化;2004年粤港澳CEPA正式实施、2008年金融危机爆发、2011年"欧债"危机加剧等离散事件的出现,则使中国外贸时间序列出现向上或向下漂移。     

基于结构方程模型的大学生生命态度影响因素研究

采用"生命态度量表"、"家庭教养方式量表"、"社会支持评定量表"和"应对方式问卷"对西安市816名大学生进行问卷调查,使用SPSS16.0和AMOS17.0统计软件对数据进行分析,探索各变量间的相关关系,并在假设模型的基础上,修正、构建各变量的结构方程模型。研究结果说明,家庭教养方式和社会支持对于大学生的生命态度有重要影响,社会支持对于应对方式有直接影响,同时家庭教养方式和社会支持还通过生命态度这一中介变量间接影响大学生的应对方式。研究结果为大学生生命教育的实施提供理论指导和实证参考。     

国际关系中的小国权力论析

国际关系中并不具备实力优势的小国往往也能发挥"以小制大"的能力,然而,用传统的权力概念理解这一现象存在一定的不足。国际关系中的"权力论",对权力的理论分类往往偏重对大国权力的关注,但从其来源、作用方式、表现形式等视角对权力的研究,对揭示小国权力具有一定的启发性。在此基础上,本文提出自然性权力、制度性权力、结构性权力和行为权力的分析框架,为理解小国的权力提供综合而全面的视角。     

城市供水企业客户满意度的实证研究

本文根据对重庆市主城区供水企业客户满意度的问卷调查,先运用因子分析法探索影响供水企业客户满要素,再通过构建客户满意的结构方程模型(Structural Equation Modeling,简称为SEM)验证关键要素与客户满意度的相关性和相关程度.最后根据分析结果提出供水企业提高客户满意度的策略建议.     

Estimation of a response surface from-a general incomplete block design

If an incomplete block design is used to compare v treatments and later it is decided to fit a second order response surface using the fact that the v treatments are v combinations of levels of m different factors, how will one proceed to obtain this? This paper demonstrates how the usual analysis of an incomplete block design with or without recovery of interblock information can be augmented to yield estimates of response surface coefficients.     

An Algorithmic Construction of Four-Level Response Surface Designs

Response surface methodology is widely used for developing, improving, and optimizing processes in various fields. In this article, we present a method for constructing four-level design matrices in order to explore and optimize response surfaces where the predictor variables are each at four equally spaced levels, by utilizing a genetic algorithm. The produced designs achieve both properties of near-rotatability and estimation efficiency.     

Evaluation of Response Surface Designs in Presence of Errors in Factor Levels

Experimenters are often confronted with the problem that errors in setting factor levels cannot be measured. In the robust design scenario, the goal is to determine the design that minimizes the variability transmitted to the response from the variables’ errors. The prediction variance performance of response surface designs with errors is investigated using design efficiency and the maximum and minimum scaled prediction variance. The evaluation and comparison of response surface designs with and without errors in variables are developed for second order designs on spherical regions. The prediction variance and design efficiency results and recommendations for their use are provided.     

Equivalence of parametric identifiability and estimability

Given that estimators are monotone functions of observations, parametric identiflability is shown to be both necessary and sufficient for estimability.     

On tests of independence between stochastic regressors and disturbances

In this paper two tests for testing the hypothesis that the stochastic endogenous regressors in a structural equation, embedded in a system of simultaneous structural equations, are independent of the disturbances in that equation are presented.