微车前隔板的强度、刚度及密封性分析

结合在上汽通用五菱汽车股份有限公司的几款微车的前隔板设计中发现的问题及设计亮点,总结了设计像前隔板这样大的薄板件时应该注意的要点,包括前隔板强度、刚度、密封性及相关零件的安装和焊接性等。     

Two-step estimation of panel data models with censored endogenous variables and selection bias

This paper presents some two-step estimators for a wide range of parametric panel data models with censored endogenous variables and sample selection bias. Our approach is to derive estimates of the unobserved heterogeneity responsible for the endogeneity/selection bias to include as additional explanatory variables in the primary equation. These are obtained through a decomposition of the reduced form residuals. The panel nature of the data allows adjustment, and testing, for two forms of endogeneity and/or sample selection bias. Furthermore, it incorporates roles for dynamics and state dependence in the reduced form. Finally, we provide an empirical illustration which features our procedure and highlights the ability to test several of the underlying assumptions.     

Block recursion and structural vector autoregressions

In applications of structural VAR modeling, finite-sample properties may be difficult to obtain when certain identifying restrictions are imposed on lagged relationships. As a result, even though imposing some lagged restrictions makes economic sense, lagged relationships are often left unrestricted to make statistical inference more convenient. This paper develops block Monte Carlo methods to obtain both maximum likelihood estimates and exact Bayesian inference when certain types of restrictions are imposed on the lag structure. These methods are applied to two examples to illustrate the importance of imposing restrictions on lagged relationships.     

样品扦样与制备-真菌毒素准确分析中的决定性因素

本文介绍了真菌毒素污染水平检测过程中,影响其准确分析和正确评价的两大决定性因素——样品扦样和样品制备。指出样品扦样作为真菌毒素检测的第一步,直接关系到结果的代表性和可靠性,是引起真菌毒素检测结果变异程度的最大原因;样品制备,与分析结果直接相关,是真菌毒素准确分析、正确评价的重要保障。对这两方面应该给予足够重视,加强有关规范和标准的制定。     

食品抽样的注意事项

食品抽样是食品安全抽样检验的首要关键,本文从食品抽样的四个环节上,依据《食品安全抽样检验管理办法》,分析食品抽样过程中应注意事项,旨在提高食品安全抽样检验的质量。     

新型固相萃取材料在样品前处理技术中的应用研究进展

固相萃取是近年来发展比较迅速的样品前处理技术,固相萃取材料的选择是影响固相萃取效率的主要因素之一。本研究对近年来新型的固相萃取材料及其在样品前处理技术中的应用进行综述,并对其未来发展的方向进行了展望。     

球壳形金属橡胶结构的静态力学性能分析

金属橡胶材料不仅具有类似橡胶的弹性性质，而且它还是一种多孔材料。针对理论描述与实际工程要求有很大差距这个问题，文章运用Amys有限元软件对球壳形金属橡胶结构进行了静态力学性能分析，并对该结构做静态实验，运用参数识别法进行曲线拟合，发现理论拟合迟滞回线与试验迟滞数据基本吻合，同时将有限元分析结果和实验结果进行对比，发现二者也基本吻合。     

Sample size determination of binomial data with the presence of misclassification

We propose a double sampling scheme with two classifiers to address the problem of optimal sample size when misclassification among binomial observations is observed. The classifiers vary with respect to the classifying cost and precision. Furthermore, since the data are unknown, an additional constraint is set on the probability of observing ``undesirable' data. The method is developed following the Bayesian point of view.     

Restricted forecasting with VAR models: An analysis of a test for joint compatibility between restrictions and forecasts

A restricted forecasting compatibility test for Vector Autoregressive Error Correction models is analyzed in this work. It is shown that a variance–covariance matrix associated with the restrictions can be used to cancel out model dynamics and interactions between restrictions. This allows us to interpret the joint compatibility test as a composition of the corresponding single restriction compatibility tests. These tests are useful for appreciating the contribution of each and every restriction to the joint compatibility between the whole set of restrictions and the unrestricted forecasts. An estimated process adjustment for the test is derived and the resulting feasible joint compatibility test turns out to have better performance than the original one. An empirical illustration of the usefulness of the proposed test makes use of Mexican macroeconomic data and the targets proposed by the Mexican Government for the year 2003.     

Inferring repeated-game strategies from actions: evidence from trust game experiments

Summary. Combining a strategy model, an inference procedure and a new experimental design, we map sequences of observed actions in repeated games to unobserved strategies that reflect decision-makers’ plans. We demonstrate the method by studying two institutional settings with distinct theoretical predictions. We find that almost all strategies inferred are best responses to one of the inferred strategies of other players, and in one of the settings almost all of the inferred strategies, which include triggers to punish non-cooperators, are consistent with equilibrium strategies. By developing a method to infer unobserved repeated-game strategies from actions, we take a step toward making game theory a more applied tool, bridging a gap between theory and observed behavior.Received: 23 December 2002, Revised: 19 April 2005, JEL Classification Numbers: C72, C80, C90.The authors are indebted for discussions with Ray Battalio, David Cooper, Robin Dubin, John Duffy, Ellen Garbarino, Susan Helper, Margaret Meyer, John Miller, Jim Rebitzer, Mari Rege, Al Roth, and John Van Huyck. The authors also benefited from discussants at economic department seminars at Case Western Reserve, McMaster and McGill University, University of Pittsburgh, SUNY-Stony Brook, and Texas A&M, and participants at the 2002 European Winter Meeting of the Econometric Society. We are grateful for the financial support provided by the Department of Economics at the University of Pittsburgh and Case Western Reserve University.