用产品工艺假定推算两大部类构成的充要条件

依据投入产出表使用产品工艺假定推算社会再生产的两大部类构成,比使用产业部门工艺假定推算更符合马克思政治经济学原理.使用产品工艺假定推算在数学上可以归结为一个带非负约束的二次规划问题.运用参数线性规划方法能够证明这样的推算存在一个充分必要条件.这一充分必要条件对于通常使用产品工艺假定与产业部门工艺假定的组合进行推算,也有作用.     

基于非对称信息和VMI模式的供应链协调模型

在假定分销商允许缺货发生和供应商控制库存的前提下,建立了一类供应——分销型供应链在对称信息和非对称信息这两种情况下的生产库存协调模型,给出了相应的最优协调策略,并通过比较对称信息与非对称信息下系统的总费用,揭示了信息对称与否对协调策略及系统总费用的影响.     

静态非线性投入产出模型的若干数学问题

SomeMathematicalProblemsoftheNolinearOutput-InputfortheStaticModelHeJianminWangDongHaoJinliangInstituteofSystemsScience,AcademicSinica100080一、非线性投入产出模型的提出建立在同质性和比例性假定上的列昂惕夫投入产出模型，假定了每一部门只有单一的消耗结构并只生产一种产品，直接消耗系数不变且非负。因假定极大地简化了经济现实，它在解决短期经济和社会问题方面取得了成功，但在长期预测和计划等方面并不十分准确。为使投入产出模型能更好地进行长期预测，人们提出各种方法来修正直接消耗系数。例如：1.专家评估法…     

两平面凸域的对称混合等周不等式

设K_k(k=i,j)为欧氏平面R~2中面积为A_k,周长为P_k的域,它们的对称混合等周亏格(symmetric mixed isoperimetric deficit)为σ(K_i,K_j)=P_i~2P_j~2-16π~2A_iA_j.根据周家足,任德麟(2010)和Zhou,Yue(2009)中的思想,用积分几何方法,得到了两平面凸域的Bonnesen型对称混合不等式及对称混合等周不等式,给出了两域的对称混合等周亏格的一个上界估计.还得到了两平面凸域的离散Bonnesen型对称混合不等式及两凸域的对称混合等周亏格的一个上界估计,并应用这些对称混合(等周)不等式估计第二类完全椭圆积分.     

最终品出口的拉动效应在单国与国际投入产出模型中的测算差异分析

中间品贸易的增加导致单国投入产出模型难以体现国家间的产业关系,所以学者们提出了国际投入产出模型.然而,目前尚没有研究对最终品在单国模型与国际模型中的测算差异进行分析.文章基于投入产出方法对二者的测算差异进行建模,给出了测算差异的公式并进行分析.最后,利用2007年的国际表分析了两个模型在测算就业和碳排放量的差异,并得出结论:单国模型低估了最终品出口的拉动效应.     

重复测量中两组均值是否相等的假设检验

在重复测量中，存在着检验两个随机试验组的各次测量均值是否相等的问题。假定所有试验对象初始值无差异，那么只需对所有均值的对比进行检验就可以了；若这个假定不成立，则需要直接检验各次测量的均值是否均对应相等。在正态性、复合对称的假定下，前一种情形已有很好的结论。针对后面一种情况，本文采用似然比检验的方法进行了检验，构造出了检验统计量的分布函数表。并对计算的精确度作了较好的控制。     

《中国经济计划与投入产出分析》一书简介

<正> 最近国际著名的英国牛津大学出版社出版了由美国马省理工大学(MIT)教授波伦斯基(K.R.Polenske)和中国科学院系统科学研究所研究员陈锡康主编的《中国经济计划和投入产出分析》一书.这本书系统而全面地总结了中国在投入产出技术的理论研究和实际应用中取得的成就,是一本具有很高学术水平和实际应用价值的专著,也是国外以英文出版的第一本关于中国投入产出技术的著作.投入产出技术是利用数学方法和电子计算机对经济系统的投入和产出进行定量分析和研究的一种技术.其创始人列昂节夫曾获得1973年诺贝尔奖.这种技术不仅可以应用于全国,而且可用于地区和企业.这本书分为三大部分,即全国投入产出,地区投入产     

n-2型黎曼空间的等距对应

<正> §1.导言一个正则的 n 维黎曼空间,若恰有 p 个函数独立的不变量,便称为 p 型的,这样的空间,我们将用 R(n,p)表之.此定义创自 T.Y.Thomas,他并详尽地研究了特殊情况:n=2,p=0,1,2.本文作者假定两个 R(n,n—2)具有结构相同的两组不变式 I_1,     

高阶极限圆型微分算子的自伴扩张

<正> 则它称为是对称的.以下恒设 l(y)为对称的微分算式.令(?)表示 L~2[0,∞)内由 l(y)所生成的最小算子,(?)为其定义域.假定(?)的亏指数为(m,m),则知 m 必满足[(n+1)/2]≤m≤n.当 m=n 时,l(y)称为是极限圆型的(简称圆型).根据 Hilbert 空间内无界算子的一般理论,在亏指数为等值的情况     

实轮换对称型及其半正定性判定的可读证明

可读证明是不等式机器证明领域中的热点问题.针对具有对称零点的实轮换对称型,文章提出了其线性空间的一组基以及分拆算法和两种分拆形式用于对不等式进行可读证明研究.讨论了该线性空间的维数,以及轮换对称型半正定性的判别方法.给出了一类具有对称零点的轮换对称型的半正定性判定条件.大量实例表明此分拆方式在轮换对称型半正定性的判定及可读证明上具有很好的实用性.     

Profust reliability of a gracefully degradable system

Research in traditional reliability theory is based mainly on probist reliability, which uses a binary state assumption and classical reliability distributions. In the present paper the binary state assumption has been replaced by a fuzzy state assumption, thereby leading to profust reliability estimates of a powerloom plant, which is modelled as a two unit gracefully degradable system. Results of Bowles and Palaez [Application of fuzzy logic to reliability engineering, Proc. IEEE 83(3) (1995) 435–449] have been deduced as a particular case of results presented here. It is also recognized that estimation of system parameters such as failure rates, is vital in reliability estimation. Available methods for such estimation do not cover the underlying uncertainty in the failure data collection involving human judgment, evaluation and decision. In this paper we introduce a new approach based on fuzzy set theory to estimate such system parameters.     

图上曲率维数不等式的若干等价性质

本文研究局部有限图上的曲率维数不等式CD(n,K)的若干等价性质,包括梯度估计、Poincaré不等式和逆Poincaré不等式.还得到了局部有限图上的修正曲率维数不等式CDE′(∞,K)的其中一个等价性质,即梯度估计.     

分片逆回归中的渐近推断

分片逆回归是最近提出的一种多元数据分析方法.这是一种有效的降维方法.使用该方法的关键点在于能给出条件协差阵一个较好的估计.为此目的,本文基于拟残差给出了一个估计,并且研究了它的渐近性质,最后给出了部分模拟结果.     

Inference of change-point in single index models

Single index models are widely used in medicine, econometrics and some other fields. In this paper, we consider the inference of a change point problem in single index models. Based on density-weighted average derivative estimation (ADE) method, we propose a statistic to test whether a change point exists or not. The null distribution of the test statistic is obtained using a permutation technique. The permuted statistic is rigorously shown to have the same distribution in the limiting sense under both null and alternative hypotheses. After the null hypothesis of no change point is rejected, an ADE-based estimate of the change point is proposed under assumption that the change point is unique. A simulation study confirms the theoretical results.     

SOME REMARKS AID PROBLEMS CONCERNING THE GEOGRAPHY OF FANO 4-FOLDS OF INDEX AND PICARDNUMBER ONE

The two-dimensional steady flow of a viscous incompressible fluid in a diverging symmetrical channel is examined. The paper exploits a new series summation and improvement technique (i.e. Drazin and Tourigny, 1996). The solutions are expanded into Taylor series with respect to the corresponding Reynolds number and the bifurcation study is perfomed. Parameter ranges for the Reynolds number, where no, one or two solutions of the given type exist, are computed.     

Optimizing the marriage market: An application of the linear assignment model

Research shows that the success of marriages and other intimate partnerships depends on objective attributes such as differences in age, cultural background, and educational level. This article proposes a mathematical approach to optimizing marriage by allocating spouses in such a way as to reduce the likelihood of divorce or separation. To produce our optimization model, we use the assumption of a central “agency” that would coordinate the matching of couples. Based on a representative and longitudinal sample of 1074 cohabiting and married couples living in Switzerland, we estimate various objective functions corresponding to age, education, ethnicity, and prior divorce concerning every possible combination of men and women. Our results show that the current state of marriages or partnerships is well below the social optimum. We reallocate approximately 68% of individuals (7 out of 10) to a new couple that we posit has a higher likelihood of survival. From this selection of new partners, we obtain our final “optimal” solutions, with a 21% reduction in the objective function.     

Warm start of the primal-dual method applied in the cutting-plane scheme

A practical warm-start procedure is described for the infeasible primal-dual interior-point method (IPM) employed to solve the restricted master problem within the cutting-plane method. In contrast to the theoretical developments in this field, the approach presented in this paper does not make the unrealistic assumption that the new cuts are shallow. Moreover, it treats systematically the case when a large number of cuts are added at one time. The technique proposed in this paper has been implemented in the context of HOPDM, the state of the art, yet public domain, interior-point code. Numerical results confirm a high degree of efficiency of this approach: regardless of the number of cuts added at one time (can be thousands in the largest examples) and regardless of the depth of the new cuts, reoptimizations are usually done with a few additional iterations. Supported by the Fonds National de la Recherche Scientifique Suisse, grant #12-42503.94.     

Estimate of solutions for differential and difference functional equations with applications to difference methods

The theorems on the estimate of solutions for nonlinear second-order partial differential functional equations mainly of parabolic type with Dirichlet’s condition and for the suitable explicit finite difference functional schemes are proved. The proofs are based on the comparison technique. The convergent difference method given is considered without an assumption of the global generalized Perron condition on the functional variable but with local one in some sense only. It is a consequence of our estimate theorems. The functional dependence is of the Volterra type.     

Control charts based on parameter depths

Control charts are designed to monitor on-going production processes by tracking subsequent samples of the production using some statistic of a quality characteristic. We propose to track the parameter depths of estimates of a parameter by means of depth (D)-charts, or the associated depth-based ranks by means of r-charts. More precisely, given a general parameter (e.g. mean, standard deviation or pair given by mean and standard deviation) and some historical data of the production, the parameter depth of an estimate of the parameter on new samples of the production with regard to the historical data is computed. The process is considered to be out-of-control when the depth of the estimate of the parameter falls below some given threshold (control limit). Some control limits of specific D-charts are obtained under the assumption of normality of the quality characteristic.     

Convexity,quality and efficiency in education

While Data Envelopment Analysis (DEA) has many attractions as a technique for analysing the efficiency of educational organisations, such as schools and universities, care must be taken in its use whenever its assumption of convexity of the prevailing technology and associated production possibility set may not hold. In particular, if the convexity assumption does not hold, DEA may overstate the scope for improvements in technical efficiency through proportional increases in all educational outputs and understate the importance of improvements in allocative efficiency from changing the educational output mix. The paper therefore examines conditions under which the convexity assumption is not guaranteed, particularly when the performance evaluation includes measures related to the assessed quality of the educational outputs. Under such conditions, there is a need to deploy other educational efficiency assessment tools, including an alternative non-parametric output-orientated technique and a more explicit valuation function for educational outputs, in order to estimate the shape of the efficiency frontier and both technical and allocative efficiency.