两大部类扩大再生产的按比例发展定理

按比例发展原理是马克思社会再生产理论中的一条重要原理.由于在经典的马克思社会再生产理论的相关公式中,生产资料、消费资料部类内部各部分之间的相互比例是固定不变的,所以这条原理当中所讲的比例,就简化为仅指两大部类之间的比例.从而,按比例发展原理成为一个十分确切的命题.已经有研究证明了从某一年起两大部类平衡增长的充要条件和静态意义下的两大部类扩大再生产的充要条件,本文区分第Ⅰ部类资本利润率不高于第Ⅱ部类和高于第Ⅱ部类两种情形,分别给出了社会扩大再生产持续进行的充分必要条件,从而使按比例发展原理深化成为"两大部类扩大再生产的按比例发展定理".这个定理为调控和优化社会再生产的决策变量标明了取值区间.     

二元矩阵有理插值函数的构造

一般构造矩阵值有理函数的方法是利用连分式给出的,其算法的可行性不易预知,且计算量大.本文对于二元矩阵值有理插值的计算,通过引入多个参数,定义一对二元多项式:代数多项式和矩阵多项式,利用两多项式相等的充分必要条件通过求解线性方程组确定参数,并由此给出了矩阵值有理插值公式.该公式简单,具有广阔的应用前景.     

热传导方程的移动边界问题

热传导问题于高温条件下,往往是可移动边界问题.文献[1]尽述了金属丝烧蚀等物理过程所确定的移动边界问题的一种求解方法.本文讨论较一般的热传导方程可移动边界问题Fourier型存在的充分必要条件,且给出问题Fourier型解.     

两大部类持续扩大再生产的优化

基于经典的马克思两大部类社会再生产公式,建立了离散确定型的持续扩大再生产的优化问题的动态规划模型.在生产资料部类的不变资本产出率高于另一部类的条件下,动态规划的指标函数是作为决策变量的生产资料部类积累率的单调函数,因而可以使用逆序解法或者顺序解法,获得唯一的最优策略和最优指标函数.借助《资本论》中的一个举例,计算验证了最优解.     

两大部类扩大再生产中的广义拉格朗日乘子

在一个带有非负和不等式约束的优化问题有最优解的情形下,存在着广义拉格朗日乘子即资源的影子价格．本文探索给出马克思两大部类扩大再生产中的影子价格,为经典的马克思扩大再生产理论增添新的重要内容．首先使用“价值系数法”替代单纯形法,简便地求得了扩大再生产优化问题的最优解．然后运用库恩一塔克条件,确立了关于最优解与广义拉格朗日乘子的互补松弛条件的三个不等式组．进而利用这些不等式组和已知的最优解,简便地解出广义拉格朗日乘子,即两大部类扩大再生产中的影子价格．最后引用和借鉴《资本论》中的两个举例,对所获得的影子价格和目标函数最优值做了计算验证．     

关于两个线性方程组同解条件的再思考

首先给出了两个线性方程组Ax=c及Bx=d的解与解之间的关系,通过对两个方程组有公共解的条件的研究,从而给出了两个方程组有同解的充分必要条件.根据所得结论,最后给出了两个线性方程组是否有同解的判别方法以及同解的求解方法.     

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.     

用解递推关系法求数列的极限

本文给出两个递推关系的求解公式,对某些递推关系通过变换化为可求通项的递推关系式,从而求出极限。如果数列的通项已知,那么,其极限就比较容易求得.而对于象由递推关系等所确定的数列,一般《高等数学》教材上,大多采用诸如单调有界有极限的原理以及级数理论等方法.但有时证明极限存在比较困难,即使假定极限存在,要求出来也并不容易。工科院校学生的数学基础理论一般比较薄弱,对求解此类极限往往不易掌握。而实际上有些由递推关系确定的数列的极限是有简便方法可寻的。本文给出两个公式,对于某些递推关系的通项的求解显得非常简单。     

线性方程组解的有关问题

首先讨论了两个齐次线性方程组有非零公共解的充分必要条件并给出了非零公共解的一般形式,然后讨论了两个线性方程组同解的一个充分必要条件和非齐次线性方程组的线性无关解向量的个数以及非齐次线性方程组通解的表达式,最后证明了非齐次线性方程组有解的一个充分必要条件.     

将生产资料分类的社会扩大再生产图解法

运用空间解析几何的作图方法,直观并且简便地获得将生产资料分类的社会扩大再生产的解,以及有解的充分必要条件.     

Generalized Green’s functions for the second-order discrete problems with nonlocal conditions

In this paper, we investigate a generalized discrete Green’s function that describes the general least squares solution of every second-order discrete problem with two nonlocal conditions. We develop the problem where the necessary and sufficient existence condition of ordinary discrete Green’s function is not satisfied. Some examples are also presented.     

Optimal resource allocation in a two-sector economic model with singular regimes

The article considers the problem of resource allocation in a two-sector economic model with a nonlinear production function of a special type. The main mathematical apparatus is Pontryagin’s maximum principle, i.e., the theorem on necessary conditions of optimality. It is shown that in the given problem the maximum principle provides a necessary and sufficient condition of optimality. A possible singular solution of the problem is found. An extremum solution is constructed in explicit form under various assumptions about the initial values. A “sufficiently long” planning horizon is assumed. An alternative approach is described, which does not use the maximum principle and instead investigates the integral representation of the optimand functional. The detailed theoretical investigation of the problem is accompanied by numerous illustrations.     

On a Quadratic Optimization Problem with Equality Constraints

The constrained optimization problem with a quadratic cost functional and two quadratic equality constraints has been studied by Bar-on and Grasse, with positive-definite matrix in the objective. In this note, we shall relax the matrix in the objective to be positive semidefinite. A necessary and sufficient condition to characterize a local optimal solution to be global is established. Also, a perturbation scheme is proposed to solve this generalized problem.     

Optimal endpoints

A complete set of necessary and sufficient conditions for selecting optimal endpoints for extremals obtained from the variational Bolza problem in control notation has been developed. The method used to obtain these conditions is based on a seldom used concept of performing a dichotomy on the general optimization problem. With this concept, the problem of Bolza is decomposed into two problems, the first of which involves the selection of optimal paths with the endpoints considered fixed. The second problem involves the selection of optimal endpoints with the paths between the endpoints taken to be stationary curves. The convenience of the dichotomy in deriving the necessary and sufficient conditions for endpoints lies in its simplicity and elementary character; well-known necessary and sufficient conditions from the theory of ordinary maxima and minima are used.An endpoint necessary condition is first obtained which is simply the well-known transversality condition. An additional condition is then developed which, together with the transversality condition, leads to a set of necessary and sufficient conditions for a given extremal to be locally optimal with respect to endpoint variations. While the second condition presented is akin to the classical focal-point condition, the result is new in form and is directly applicable to the optimal control problem. In addition, it is relatively simple to apply and is easy to implement numerically when an analytical solution is not possible. It should be useful in situations where the transversality conditions yield more than one choice for an optimal endpoint.An analytic solution for a simple geodetics problem is presented to illustrate the theory. A discussion of numerical implementation of the sufficiency conditions and its application to an orbit transfer example is also included.This work was supported in part by the National Aeronautics and Space Administration, Grant No. NGR-03-002-001.     

Necessary and sufficient conditions for power convergence rate of approximations in Tikhonov’s scheme for solving ill-posed optimization problems

We investigate a rate of convergence of estimates for approximations generated by Tikhonov’s scheme for solving ill-posed optimization problems with smooth functionals under a structural nonlinearity condition in a Hilbert space, in the cases of exact and noisy input data. In the noise-free case, we prove that the power source representation of the desired solution is close to a necessary and sufficient condition for the power convergence estimate having the same exponent with respect to the regularization parameter. In the presence of a noise, we give a parameter choice rule that leads for Tikhonov’s scheme to a power accuracy estimate with respect to the noise level.     

Vector Variational Inequality and Vector Pseudolinear Optimization

The study of a vector variational inequality has been advanced because it has many applications in vector optimization problems and vector equilibrium flows. In this paper, we discuss relations between a solution of a vector variational inequality and a Pareto solution or a properly efficient solution of a vector optimization problem. We show that a vector variational inequality is a necessary and sufficient optimality condition for an efficient solution of the vector pseudolinear optimization problem.     

Iterative Methods for Pseudomonotone Variational Inequalities and Fixed-Point Problems

In this paper, we introduce an iterative scheme for finding a common element of the set of solution of a pseudomonotone, Lipschitz-continuous variational inequality problem and the set of common fixed points of an infinite family of nonexpansive mappings. The proposed iterative method combines two well-known schemes: extragradient and approximate proximal methods. We derive some necessary and sufficient conditions for strong convergence of the sequences generated by the proposed scheme.     

Resource allocation problem in a two-sector economic model of special form

In the present paper, we study the resource allocation problem for a two-sector economic model of special form, which is of interest in applications. The optimization problem is considered on a given finite time interval. We show that, under certain conditions on the model parameters, the optimal solution contains a singular mode. We construct optimal solutions in closed form. The theoretical basis for the obtained results is provided by necessary optimality conditions (the Pontryagin maximum principle) and sufficient optimality conditions in terms of constructions of the Pontryagin maximum principle.