关于二阶非线性微分方程全局渐近稳定的充要条件

本文研究了二阶非线性微分方程x″+f(x,x′)=0全局渐近稳定的充要条件,并推广了文[5](8][9]中的定理。     

一类非线性中立型泛函微分方程振动的充要条件

给出非线性中立型泛函微分方程，ｘ（ｔ），ｘ（ｔ－τ＿ｊ（ｔ）））＝０振动的充要条件是，微分不等式无最终正解．     

伪距差分GPS定位误差分析

提出了ＧＰＳ测量误差模型，并在此基础上第一次给出了伪距差分ＧＰＳ的ＲＭＳ误差表达式。这个误差表达式揭示了影响伪距差分ＧＰＳ定位精度的误差源及其影响大小。分析表明，不同于ＧＰＳ直接定位，伪距测量随机误差已是伪距差分ＣＰＳ的主要误差源之一。     

双渗渗流数学模型的精确解

针对双渗油藏的渗流特征,在两渗流层之间存在流体的交换;以往的双渗油藏并没有考虑流体之间的渗流,仅仅将两层之间的流体交换作为源和汇;在此考虑了两层之间渗流耦合的微分方程及压差对两层的影响,对方程采用无因次化,而将方程简化。通过正交变换获得该模型的精确解,该解对理解双渗油藏的渗流规律和试井分析都具有重要的指导意义。     

A kind of stochastic recursive Zero-Sum differential game problem with double obstacles constraint

Abstract

This paper concerns a class of stochastic recursive zero-sum differential game problem with recursive utility related to a backward stochastic differential equation (BSDE) with double obstacles. A sufficient condition is provided to obtain the saddle-point strategy under some assumptions. In virtue of the corresponding relationship of doubly reflected BSDE and mixed game problem, a stochastic linear recursive mixed differential game problem is studied to apply our theoretical result, and here the explicit saddle-point strategy as well as the saddle-point stopping time for the mixed game problem are obtained. Besides, a numeral example is also given to demonstrate the result by virtue of partial differential equations (PDEs) computation method.     

中国城乡居民收入差距的统计学分析

改革开放以来,中国经济开始由传统计划经济向社会主义市场经济转型,经济发展创造了世界公认的奇迹——经济高速增长和低通货膨胀,同时国民收入分配格局发生了较大的变化,出现了一些新问题,其中城乡居民收入差距逐步扩大就是面临的主要问题之一。通过对城乡居民收入差距、城乡居民收入的内部差距、城乡居民收入的地区差距、城乡居民收入差距的动态演变的分析,提出缩小城镇居民收入差距的6项措施和缩小农村居民收入差距的5项措施。     

女大学生就业与高校差别教育

近年来我国女大学生的求职过程更难,找到理想工作的机会更少,就业岗位低层次化倾向严重。分析了这一现象产生的主、客观原因,并提出在理论上、观念上承认性别差异,弘扬适应时代要求的女性新文化,设置符合女性身心发展规律的特色课程,开展个性化就业指导等体现性别关怀的差别化教育方式作为对策参考。     

经济适用房定价微分博弈模型及福利分析

经济适用房存废之争日益激烈,尤其是经济适用房定价问题广受质疑。地方政府与开发商博弈经济行为影响到经济适用房的定价和供给量。本研究采用Stackelberg微分博弈模型演绎了经济适用房定价、供给量和政府补偿的收敛趋势,进一步阐释了限价房摇号随机配给机制可能造成的住房福利损失。结论是地方政府采取的激励强度和开发商的利润追求动力驱动了经济适用房定价过程,经济适用房不能废弃,并且供给量需要维持在一定的水平,切实保障对经济适用房的住房边际效用高的群体购买,才能减少公共住房福利损失。     

常系数线性微分方程初值问题的算子解法

以算子作工具,给出了常系数线性微分方程(组)初值问题的一种解法.     

ESTIMATING PREDATOR-PREY SYSTEMS VIA ORDINARY DIFFERENTIAL EQUATIONS WITH CLOSED ORBITS

This paper considers periodic regression functions, which are solutions to a planar system of differential equations. In particular, it introduces a simple stochastic model which describes the interaction between predator and prey populations. The regression functions are solutions to the classical Lotka‐Volterra system of equations, which admits closed orbits. The proposed method of estimation can be applied whenever pairs of predator‐prey data are available, and the prey is the main source of food of the predator. Canadian mink‐muskrat data are analysed from this new viewpoint. The estimation method is based on the existence of closed trajectories that describe the relationship between the two population sizes, and the paper shows how it can be extended to other systems of differential equations which admit closed orbits (e.g. Hamiltonian systems).