A profit-maximization location-capacity model for designing a service system with risk of service interruptions

This paper considers the design of an immobile service system in which each facility’s service process is subject to the risk of interruptions. The location-capacity decisions and allocations are simultaneously made to maximize the difference between the service provider’s profit and the sum of customers’ transportation and waiting costs. An efficient Lagrangian-based solution algorithm is developed, which solves large-sized instances with up to 50 service facilities and 500 customers in a few seconds. Several sensitivity analyses and managerial insights are presented. The model is also applied to a case study on a logistics network design problem in the zinc mining industry.     

非线性定价的福利再分配效应研究——基于非对称双寡头市场的分析

较之"线性定价","非线性定价"在社会福利方面的优势被现有理论反复证明。在肯定"非线性定价"方式能够改进社会总福利的同时,指出并不是每一个市场主体的福利水平都能够通过"非线性定价"方式得到改进。通过建立模型、计算和比较分析,提出了在上述两种情况下,"非线性定价"可能会对特定的市场主体产生"福利剥夺",从而出现福利再分配效应。     

Noisy chaotic dynamics in commodity markets

The nonlinear testing and modeling of economic and financial time series has increased substantially in recent years, enabling us to better understand market and price behavior, risk and the formation of expectations. Such tests have also been applied to commodity market behavior, providing evidence of heteroskedasticity, chaos, long memory, cyclicity, etc. The present evaluation of futures price behavior confirms that the resulting price movements can be random, suggesting noisy chaotic behavior. Prices could thus follow a mean process that is dynamic chaotic, coupled with a variance that follows a GARCH process. Our conclusion is that models of this type could be constructed to assist in forecasting prices in the short run but not over long run time periods.First version received: June 2001/Final version received: March 2003     

预应力混凝土桥梁钢束锈蚀分析

针对锈蚀钢束与混凝土间存在的粘结与滑移问题,基于桥梁分析中常用梁单元的特点,以Saenz公式和Skogman公式分别作为混凝土和预应力钢束的应力-应变本构关系,采用非线性弹簧模拟,提出刚臂元-非线性弹簧元-钢束元的方法,对锈蚀钢束与混凝土之间的粘结滑移进行分析。并以具体工程实例进行了分析计算,证明了所提出的方法用于预应力混凝土桥梁关于钢束锈蚀非线性分析的有效性。     

广义非线性轴向运动弦的参数分析

本文的研究对象是服从边界控制的非线性轴向运动弦。弦线的运动方程以及边界条件都是根据Hamilton原理得出的。Laypunov关于运动的稳定性理论,特别是他的"直接法",为非线性系统的稳定性分析提供了一个有效且方便的工具,已经成为近代控制论的一个坚实的基础。     

我国财政支出对经济增长非线性效应——基于省级面板数据的平滑转移模型实证分析

文章基于我国1997-2009年省级面板数据,采用数据本身隐含信息进行内分组的面板平滑转移模型来检验财政支出与经济增长之间的非线性效应,并进一步拓展了Armey曲线推论。研究发现,我国省级政府财政一般预算支出规模和财政支出结构均与经济增长之间存在Armey曲线所描绘的非线性效应,其中财政一般预算支出最优规模为9.32%,财政支出最优结构为1.643,并且财政一般预算支出规模与财政支出结构都在最优值两侧对经济增长的影响具有不对称性,相比而言,财政一般预算支出规模的转换速度似乎更快。这意味着现阶段我国财政一般预算支出规模与财政支出结构不合理,需要政府提高财政支出效率。     

我国收入分配对消费需求的影响

现阶段我国收入分配差距不断扩大,具体表现在城乡之间、地区之间以及劳资之间。通过对社会总消费函数和人均消费函数进行非线性回归分析可以发现,社会总消费函数的边际消费倾向大大低于人均消费函数的边际消费倾向。收入分配差距造成了社会总消费函数的边际消费倾向对人均消费函数的边际消费倾向的大幅偏离。因此,要提高整个社会的边际消费倾向,必须努力缩小我国的收入分配差距,改善地区之间收入分配状况,加强收入再分配的调节作用。     

资本集聚与经济增长的非线性研究——基于系统动态GMM估计和门槛回归的经验分析

文章基于改进的C-D生产函数构建动态计量模型,利用中国1992-2011年的30个省市的面板数据及系统GMM估计方法,验证了资本集聚与经济增长间的非线性关系的存在性,并对计量模型进行修正建立了门槛回归模型,进行了门限回归,结果表明:资本集聚与经济增长间存在单一门槛值,而且资本集聚水平与交易成本存在此消彼长的关系。据此结论提出政策建议:我国东部沿海地区部分制造业行业资本集聚过度,应该进行资本流向管理及政策引导,让过剩资本流向周边及西部资本相对短缺的地区;中西部落后地区应该创造有利条件,增强资本集聚的动力,充分利用资本集聚的积极效应加快经济增长;同时应该对各种集聚资本的质量加强考核与监管。     

China feels the heat: negative impacts of high temperatures on China's rice sector

We analysed a county‐level data set of single‐season rice yield and daily weather outcomes in China to examine the effects of temperature on China's rice sector. We found that rice yield exhibited highly nonlinear responses to temperature changes: rice yield increased with temperature up to 28°C and decreased sharply with higher temperatures. Holding current growing seasons and regions constant, average rice yield in China is projected to decrease by 10–19 per cent by 2050 and 11–33 per cent by 2070 due to future warming under the global climate models HadGEM2‐ES and NorESM1‐M. These results imply that future warming poses a major challenge for Chinese rice farmers and that the effectiveness of adaptations will depend on how well they reduce the negative temperature impacts on rice yield because of very hot days.     

Jeffcott转子系统分岔点预测

首先简述了一种用于转子轴承系统的稳定性量化分析方法,即首先利用数值积分对高维非线性转子系统进行解耦,将Rn轨线映射为一系列R1映像轨线,然后在R1观察空间中定义轨线的稳定裕度,根据轨线稳定裕度利用灵敏度技术预测动力系统的分岔点。最后,对一个单跨转子模型试验台建立了动力学方程,并利用上述方法通过2个算例预测了系统发生分岔的参数值和分岔特性。预测结果与直接数值积分法在庞加莱截面得到的分岔参数值基本一致,但由于该方法利用了灵敏度技术,所以其分岔点的搜索过程比直接数值积分法中的试探法要快得多。