流体力学新型通用函数Y的变分有限元分析

本文应用通用函数Y及其变分原理,为求解具有自由面流动问题提出了一种新方法。将物理平面变换成映象平面。在映象平面上,引出通用函数Y,并且写出关于Y的变分原理。用这个变分原理及有限元法求解自由面流动可克服边界未知的困难。文中以水坝闸门出流问题为例进行了计算,结果表明,该方法是非常有效的。     

可数集类的共性集

讨论了有限集类在增补集合的情况下同阶共性集的相互联系，有限集类的共性集与可数集类的共性集之间的极限关系，得出了可数事件的共性事件概率公式．     

Global Trade Models and Economic Policy Analyses: Relevance,Risks and Repercussions for Africa

Computable general equilibrium models are widely used for trade policy analyses and recommendations. There is, however, increasing discomfort with the use of these models, especially in Africa. This article demonstrates that the results of several such studies of the impact of trade reforms in Africa differ drastically in terms of both magnitude and direction, failing to take account of key features of African economies. It also outlines potential consequences of the misuse of CGE models for policy evaluation and suggests pitfalls to be avoided.     

邓小平辩证发展观与和谐社会的构建

研究邓小平辩证发展观时,学术界往往较多关注其非均衡发展思想,而忽略对其"综合平衡"均衡发展思想的研究,针对这一现状,分析了邓小平均衡与非均衡辩证发展观及其对构建和谐社会的作用。分析认为:均衡发展不是社会各方面同步发展,非均衡发展并非是"单打一"的发展;均衡与非均衡发展应是在差异基础上的"和谐"共进,是均衡发展与非均衡发展的有机统一。当前重新认识和深刻领会邓小平辩证发展观对于和谐社会的构建无疑具有重要的现实意义。     

基于行程时间可靠性的随机交通网络均衡模型

考虑现实条件下交通网络的不确定性状态，提出了从确定型网络到不确定型网络状态下出行者路径选择行为的改变，及基于行程时间可靠性的路径选择模型。并将可靠行程时间的路径选择行为纳入到随机交通网络平衡分配模型中，证明了模型的等价性和唯一性。在一个小型测试网络上对模型分配结果进行了测试，测试结果与经验相吻合，表明模型具有较好的现实可行性。     

Comment on An and Schorfheide's Bayesian Analysis of DSGE Models

An and Schorfheide's article provides an excellent review of Bayesian estimation of DSGE models. Rather than recapitulating the points already made in this article, my comment focuses on three aspects. It proposes a convergence measure to take account of serial correlation of MCMC draws, explains why the DSGE-VAR framework for policy analysis can be improved by avoiding the ad hoc identification assumption, and discusses an alternative structural approach to model misspecification.     

Competition and Coordination in Two‐Tier Public Service Systems under Government Fiscal Policy

As a result of government budgetary limits and rapid market growth, many public service systems—such as health care—are characterized by extensive customer wait times that have become a serious problem. This problem might be solved by allowing private firms to enter these markets, which would provide customers with a choice between a free (governmental) public service provider (SP) and a fee‐charging (or “toll”) private SP. In such a two‐tier service system, the two SPs are differentiated by service quality and cost efficiency. This study focuses on the competition and coordination issues for two‐tier service systems with customers who are sensitive to both service quality and delay. The free system attempts to maximize its expected total customer utility with limited capacity, whereas the toll system attempts to maximize its profit. Neither goal is aligned with the social welfare goal of the public service. To achieve the social welfare goal, the government plays a crucial role in coordinating the two‐tier service system via the budget, the tradeoff of social members' goals, and tax‐subsidy policies. Using a mixed duopoly game, we establish Nash equilibrium strategies and identify the conditions for the existence of the two‐tier service system. We employ several interesting and counter‐intuitive managerial insights generated by the model to show that the public service can be delivered more efficiently via customer choice and SP competition. In addition, we show that a relatively low tax‐subsidy rate can almost perfectly coordinate the two SPs to achieve most of the maximum possible benefit of the two‐tier service system.     

农业合作社的经济均衡——基于新古典框架的分析

在完备市场和经济理性人假设下,采用新古典框架对合作社进行经济均衡分析,是对合作社的性质及其在农产品市场中所起作用研究的重要方面。在整理已有文献的基础上,将合作社视为追求单一目标的特殊企业组织形式,分别构建了传统购买、销售合作社及新型深加工合作社的经济均衡模型。研究发现,传统购买销售合作社为生产资料的卖方垄断和农产品买方垄断市场增加了竞争性因素,使农业生产效率提高,均衡产量增加。新型深加工“合作社—农户社员”系统存在一种自我调节机制,使系统在偏离均衡状态时自动向均衡方向调节。这一模型解释了“新一代合作社”中“股份—交易份额”同一的规定,如何使其保持在最大生产效率下经营。     

心理期望：政治认同生成的内隐机制

政治认同是公民对国家政治诸要素所产生的一种心理上的归属感。心理期望作为政治认同的内隐机制,从需要因素看,可分为自发性政治认同需要和引致性政治认同需要。而对需要的满足,则取决于主体的自我政治期望和社会政治期望的契合程度及运行路向。现实问题往往因对期望的认知错位而产生各异的政治认同距离进而给个体和政府等带来心理压力。如何把这种压力保持在一定的安全阈值范围内而使政府和个人在期望心理供求方面处于大体均衡,成为优化政治认同效果的现实选择。     

西方现代区位理论述评

西方现代区位理论是在古典区位理论的基础上，通过对古典区位论的假设条件不断放宽，使其更能在一般的条件下较为准确地解释现实经济，从而更好地指导经济主体的区位选择活动。在现代区位论里，新古典区位论放宽了古典区位论的某些假设条件，坚持完全竞争的市场结构，把规模报酬递增当作外生变量，在个体最优化和一般均衡模型下研究区位选择，使区位选择研究从局部均衡向一般均衡发展；新经济地理学派区位论利用迪克斯特与斯蒂格利茨建立的垄断竞争模型，并借助萨缪尔森的“冰山”原理以及后来的博弈论和计算机技术等分析工具，把区位因素纳入西方主流经济学的分析框架，并用严密的数学模型把区域经济活动聚集和扩散的内在机制表达出来，努力把空间因素纳入主流经济学的理论体系，使区位理论在不完全竞争和规模报酬递增的框架下获得新发展。