关于地球健康的双层耦合网络模型

建立了一个基于平均场动力学的微分方程组和反应—扩散模型的双层耦合网络模型,用来分析、预测及评价地球生物与环境的健康问题。在双层耦合网络模型中,根据地球地理和气候分布,将全球划分为九块区域,并以此作为全球网络的节点;同时,七个具有代表性的反映地球健康状况的元素,如人口密度、森林、空气质量、生物多样性等,被挑选出作为元素网络的节点。再通过平均场动力学微分方程,建立并描述了各个元素间的联系与相互作用;利用数据确定模型参数,从而完善模型,最后,以此模型完成寻找临界点、灵敏度分析、网络结构分析、引入不确定性等工作。     

Existence and duality theory for separated continuous linear programs

This paper surveys the recent developments in the theoretical study of separated continuous linear programs (SCLP). This problem serves as a useful model for various dynamic network problems where storage is permitted at the nodes. We demonstrate this by modelling some hypothetical problems of water distribution, transportation and telecommunications. The theoretical developments we present for SCLP fall into two main topics. The first of these is the existence of optimal solutions of various forms. These results culminate in one guaranteeing the existence of a piecewise analytic optimal solution, that is, having a finite number of breakpoints. The second topic we discuss is duality. Under this heading we develop a theory that closely resembles that for finite-dimensional linear programming. For instance, we define complementary slackness and give conditions under which there exist complementary slack primal and dual optimal solutions. Throughout the paper we observe that the main theorems are sufficiently general to include any reasonable practical problems     

Case studies in dynamic modelling of large-scale wastewater treatment plants

Several large-scale wastewater treatment plants have been modelled successfully using an extensive modelling library in the General Purpose Simulator, GPS-X. The mathematical models included all important processes on the selected wastewater treatment plants, i.e. primary sedimentation, activated sludge biokinetics and final clarification.The models have been used in different areas, such as: a)analysis of operational scenarios; b) determenation of sustained and peak capacity of plants(rated plant capacity) and c) investigation of plant expansion scenarios. Out of more than twenty documented cases four, involving simulation studies on large-scale wastewater plants are discussed.     

寡头垄断市场三度价格歧视动态博弈分析

对两寡头厂商2元市场用完全信息动态博弈的方法分析了实施三度价格歧视情形和统一定价情形的均衡产量,均衡价格和均衡总收益,并研究了这两种情形三个指标之间的关系.结果显示,在两个子市场的需求函数为线性需求的条件下,统一定价的市场均衡产量等于歧视定价的市场均衡产量;统一定价的均衡价格是歧视定价时两个子市场均衡价格的加权平均;统一定价的市场均衡总收益小于歧视定价的市场均衡总收益.     

Three Point Boundary Value Problems on Time Scales

This work formulates existence theorems for solutions to three-point boundary value problems on time scales. The ideas are based on a relationship between the three point boundary conditions, lower and upper solutions and topological degree theory.     

Delay equations on time scales: Essentials and asymptotics of the solutions

The paper discusses the notion of a delay dynamic equation on time scales and describes some asymptotic properties of its solutions. The application of the derived results to continuous and discrete time scales presents new qualitative results for delay differential and difference equations. In particular, our approach faciliates the joint investigation of stability properties of the exact equations and their numerical discretizations.     

Existence of extremal solutions by approximation to a first-order initial dynamic equation with Carathéodory's conditions and discontinuous non-linearities*

This paper is devoted to the study of the existence of extremal solutions to a first-order initial value problem on an interval of an arbitrary time scale. We prove the existence of extremal solutions for problems satisfying Carathéodory's conditions. Moreover, they are approximated uniformly by a sequence of lower and upper solutions to this problem, respectively.

We also can warrant the existence and approximation of extremal solutions for the problem by relaxing their continuity properties.     

基于“又好又快发展”思想的动态综合评价方法

针对不同时段内被评价对象增益的不同,提出了一种基于"又好又快发展"思想的动态综合评价方法.首先依据时序立体数据信息,求出被评价对象的增益水平;然后通过均值相对运算、规范化和一致性运算,定义出各被评价对象各指标在某一时刻的相对发展增益权、均衡发展增益权和可持续发展增益权,并进一步计算综合增益权;最后依据激励思想给出增益权与静态综合评价值的合成规则.通过2006-2010年中部六省三次产业"又好又快发展"水平评价的实例分析,证明了方法的科学性.     

资本账户开放对浮动汇率制度福利的非线性效应:以新兴市场经济体为例

通过构建一个带有随机冲击的开放经济模型,采用比较静态分析与动态分析相结合的方法,探讨了新兴市场经济体资本账户开放对浮动汇率制度福利变化的影响.结果显示,资本账户开放度对浮动汇率制度的福利变化具有显著的非线性效应.浮动汇率制度"吸收器"功能的有效发挥不仅取决于一国资本账户开放度偏离其最优资本账户开放度的位置,还受本国资本账户开放度变化量的影响.得到我国资本账户开放进程中人民币汇率制度改革的启示是:我国仍应在坚持可控、渐进的原则下,逐步推进人民币汇率制度改革与资本账户开放,并注意两者之间的搭配与协调.