经济学中拟齐次生产模型的几何刻画

齐次和拟齐次生产函数作为经典的生产函数模型,在经济分析中具有广泛的应用.从几何学的角度研究齐次和拟齐次生产函数的分类具有重要理论意义和应用价值.该研究利用几何不变量方法,完全分类了拟齐次生产函数所对应的平坦拟齐次生产曲面,并且也给出了极小拟齐次生产曲面的完整分类.     

Estimate of the Constant in Two Strengthened C.B.S. Inequalities for F.E.M. Systems of 2D Elasticity: Application to Multilevel Methods and a Posteriori Error Estimators

The constant γ in the strengthened Cauchy-Buniakowski-Schwarz (C.B.S.) inequality plays a crucial role in the convergence rate of multilevel iterative methods as well as in the efficiency of a posteriori error estimators, that is in the framework of finite element approximations of SPD problems. We consider the approximation of the 2D elasticity problem by the Courant element. Concerning multilevel convergence rate, that is the γ corresponding to nested general triangular meshes of size h and 2h, we have proved that γ²≤ 3/4$ uniformly on the mesh and the Poisson ratio. Concerning error estimator, that is the γ corresponding to quadratic and linear approximations on the same mesh, numerical computations have shown that the exact γ for a reference element deteriorates that is goes to one, when the Poisson ratio tends to 1/2     

Applying the maximum NPV rule with discounted/growth factors to a flexible production scale model

This study examines the maximum net present value of the market entry and exit thresholds derived by the traditional net present value method and combines the real options approach for the project investment or disinvestment. The discounted and growth factors are incorporated into the proposed entry and exit models, facilitating the complicated calculations required to identify the discounted and growth rates so as to assess and determine the expected present value of uncertain cash flow streams. Consequently, this investigation successfully combines applying the maximum net present value method and the real options approach to decision-making with the simple consideration of the discounted and growth factors in the flexible production scale model.     

A note on the economics of exhaustible resources under production capacity constraints

We derive an interesting general result on the effect of production capacity constraints on natural resource planning models. Basic Hotelling theory is extended to include such constraints.     

多变量整体模式累加多层统计模型的建立及其在组织绩效预测上的应用研究

为了解决多层的少样本或无规则数据的建模问题,在一般多层统计模型的基础上提出了多变量整体模式的累加多层统计模型。此模型把累加方法的优点(将无规则数据转化成有规则数据)与多层统计模型结合起来,拓展了多层统计模型的适用范围。从其在香蕉组织绩效的分析以及在仅有两个调查数据香蕉组织形式绩效的预测中,可以看出此模型有较强的实用性。     

An application of the neural network energy function to machine sequencing

We apply a neural network approach for solving a one-machine sequencing problem to minimize either single- or multi-objectives, namely the total tardiness, total flowtime, maximimum tardiness, maximum flowtime, and number of tardy jobs. We formulate correspondingly nonlinear integer models, for each of which we derive a quadratic energy function, a neural network, and a system of differential equations. Simulation results based on solving the nonlinear differential equations demonstrate that our approach can effectively solve the sequencing problems to optimality in most cases and near optimality in a few cases. The neural network approach can also be implemented on a parallel computing network, resulting in significant runtime savings over the optimization approach. This paper should not be disseminated without written permission of the authors.     

中国电力消费与经济增长关系:基于生产函数和Logistic曲线

将电力作为生产函数的投入要素,结合岭回归的方法,分析中国1990—2012年资本、人力和电力消费与经济增长之间的动态关系,并使用Logistic曲线模型寻找中国电力消费增长的拐点.结果显示,1990—2012年,劳动力是推动中国经济增长的主要动力,年均贡献率达40.17%,资本的贡献率呈稳步增长态势,平均贡献率为34.57%,电力消费的经济贡献率在振荡中逐渐上升,平均贡献率为30.13%;1999年之前是中国电力消费的渐增期,从2006年开始进入快增期,电力消费快速增长,从2011年开始,中国的电力消费进入缓增期,此后电力消费将有所放缓,并逐渐趋于稳定,但由于巨大的电力消费基数,能源供应压力依然十分巨大.     

Methodological Issues in Studying Effects of Networks in Organizations

Three methodological issues are discussed that are important for the analysis of data on networks in organizations. The first is the two-level nature of the data: individuals are nested in organizations. This can be dealt with by using multilevel statistical methods. The second is the complicated nature of statistical methods for network analysis. The third issue is the potential of mathematical modeling for the study of network effects and network evolution in organizations. Two examples are given of mathematical models for gossip in organizations. The first example is a model for cross-sectional data, the second is a model for longitudinal data that reflect the joint development of network structure and individual behavior tendencies.     

Decomposing technical efficiency and scale elasticity in two-stage network DEA

The constant returns to scale assumption maintained by neoclassical theorists for justifying the black-box structure of production technology in long run does not necessarily allow one to infer that there are no scale benefits available in its sub-technologies. Most of real-life production technologies are multi-stage in nature, and the sources of increasing returns lie in the sub-technologies. It is, therefore, imperative to estimate the scale economies of a firm not only for the network technology but also for the sub-technologies. To accomplish this, two approaches are suggested in this contribution, based on the premise concerning whether a network technology construct considers allocative inefficiency. The first approach, which is ours, makes use of a single network technology for two interdependent sub-technologies. The second approach, which is due to Kao and Hwang (2011), however, assumes complete allocative efficiency by considering two independent sub-technology frontiers, one for each sub-technology. The distinction between these two approaches is important from a policy point of view since the network efficiencies revealed from these two approaches have distinctive causative factors that do not permit them to be used interchangeably.     

广东企业规模效应的实证研究

应用C-D函数和影响因子构建了行业内不同企业和不同行业间企业的兼并模型.在此基础上,以广东的家电行业的两个企业兼并绩效进行了实证分析和研究,并得到了三个有理论指导意义的结论.