INCOME DISTRIBUTIONS IN INPUT-OUTPUT MODELS

The analysis of income distribution (ID) has traditionally been of prime importance for economists and policy-makers. However, the standard input–output (I–O) model is not particularly well equipped for studying current issues such as the consequences of decreasing access to primary inputs or the effects of specific redistributive policies. This paper addresses this gap in the existing literature. We propose that IDs can excellently be studied by restructuring the I–O relations. A new coefficients matrix is defined, the so-called augmented input coefficients matrix. This matrix is the sum of the intermediate input coefficients matrix and newly constructed matrices of sector-specific input coefficients that represent the existing distribution of income. We show that shifts in the distribution can be modelled by attributing weights to these matrices and vary these according to system-specific rules. Numerical illustrations based on the existing literature are given throughout the paper.     

遗传算法在装配线平衡中的应用

装配线平衡是混合装配生产线调度的重要基础,是面向订单装配(ATO)得以实施的技术瓶颈,对提高生产率和设备利用率也具有重要意义。在工位数量给定的条件下,文章针对装配线平衡的数学模型,提出了一种面向装配线平衡的非标准遗传算法。该算法基于各操作之间的逻辑优先关系产生可行操作序列而生成初始种群,保证解的可行性;在此基础上实现寻找最小节拍、选定较优序列进行遗传,并采用最优保存策略确保算法收敛到最优或近优解。最后通过实例验证了该算法的有效性和可行性。     

The existence of sampling designs with preassigned inclusion probabilities

Summary The question of the existence of a sampling design realizing given preassigned inclusion probabilities is treated. The question can be fully answered in the case of inclusion probabilities of first order. If the inclusion probabilities of second order are given it is shown why necessary and sufficient conditions for the existence of a corresponding sampling design can be derived only in very special cases.     

The RAS Approach in Updating Input–Output Matrices: An Instrumental Variable Interpretation and Analysis of Structural Change

The main purposes of the paper are to reconsider the rationale of the RAS method, and to attempt to improve on its interpretation and usefulness. The substitution and fabrication factors in the RAS method are interpreted as statistical estimates obtained by the method of instrumental variables. This enables the computation of asymptotic standard errors for the factors and the relative precision of the predicted technical coefficients. Furthermore, an adjustment cost minimization model to describe how a sector determines its substitution and fabrication factors is presented. The solutions of the model provide another rationale for the RAS method, and the associated Lagrangian multipliers can be useful for assessing structural constraints and structural change.     

试论国有企业创新

针对当前企业标捉化工作缺乏整体性 ,从而难以发挥其基础作用和企业整体功能这一现象 ,本文结合企业实例 ,运用层次分析法对企业管理标准体系进行优化 ,使企业的标准化工作能在分清轻重缓急的条件下有序地开展 ,以强化企业基础工作、为现代企业管理理论和方法的应用提供必要的     

秩幂等矩阵的特征

如果n阶方阵A满足秩(A2)=秩(A),那么称A为秩幂等矩阵.利用线性代数的方法研究秩幂等矩阵的性质,得到了秩幂等矩阵的一些充要条件,揭示了秩幂等矩阵A的值域、核子空间与线性空间Pn的联系.     

一种基于QoS的多任务实时集群系统负载均衡算法

负载均衡算法是多任务实时集群系统的一个关键技术。在分析了常见的轮转式均衡调度算法和任务最少优先法的优缺点基础上，针对实时集群系统处理多类任务的特点，引入了加权负载率的概念来更准确地描述各分布式集群节点的负载状况。提出了通过任务QoS映射为负载权值的思想，并给出了一种改进的任务最少优先算法——加权负载率最小法，描述了以加权负载率表为核心的多任务均衡调度算法。最后，通过仿真验证了该算法明显优于前两种算法。     

基于现代设计方法学的平面研磨机设计

针对现有大回转半径平面研磨机整机重、效率低的问题,采用现代设计方法学为指导,给出了平面研磨机的黑箱模型和整机功能的形态学矩阵,依据形态学矩阵设计了多工位、大回转半径平面研磨机系统方案,并讨论了主要的研磨参数.     

Modeling and optimizing the integrated problem of closed-loop supply chain network design and disassembly line balancing

This paper describes an integrated model that jointly optimizes the strategic and tactical decisions of a closed-loop supply chain (CLSC). The strategic level decisions relate to the amounts of goods flowing on the forward and reverse chains. The tactical level decisions concern balancing disassembly lines in the reverse chain. The objective is to minimize costs of transportation, purchasing, refurbishing, and operating the disassembly workstations. A nonlinear mixed integer programming formulation is described for the problem. Numerical examples are presented using the proposed model.     

一阶常系数线性齐次微分方程组的两种解法

一阶常系数线性齐次微分方程组其中的求解,一般有两种解法。第一种,归结为求矩阵A的特征值和特征向量,微分方程组(1)的解的一般结构完全由代数问题的解所决定。第二种,归结为求矩阵A的Jordan标准形,从而可以写出,由其中为可逆矩阵,求出即为方程组(1)的解。