求解用户平衡与系统最优模型的新算法

近些年,国内外许多学者针对交通规划提出了诸如用户平衡(UE)、系统最优(SO)等模型,但由于交通网络的复杂性,这些模型的求解相对困难,考虑到在一般的UE、S0模型中,其约束条件为线性约束与非负约束,给出一种求解交通规划模型的新算法,算法不需使用任何线搜索,只要通过求解一个简单的二次规划问题得到下降方向即可,最后,将该算法应用到简单的交通网络中,并通过与相继平均法(MSA)进行比较,验证了该算法的收敛速度较快。     

具有垂直传染的SEIA传染病模型的稳定性

建立和研究一类具有垂直传染的SEIA传染病模型,得到模型基本再生数R₀的表达式,运用Lyapunov函数和第二加性复合矩阵理论证明了当R₀〈1时无病平衡点全局渐近稳定,当R₀〉1时地方病平衡点全局渐近稳定.     

随机需求下两条供应链的货架展示量竞争与链内协调研究

针对两条分别由单生产商单零售商组成的替代产品供应链,假定两种产品的随机总需求依赖于总货架展示量、而每种产品的市场份额与其货架展示量成正比,利用均衡分析方法研究两条供应链在货架展示量与订货量方面的竞争均衡,分别建立了对应两条供应链均为分散式供应链、均为集中式供应链、一条为分散式供应链一条为集中式供应链的EPEC、MPEC和Nash均衡模型。随后分析了供应链竞争下的链内协调合同设计问题,给出了同时协调零售商的货架展示量和订货决策的回购加线性补贴合同和收益共享加线性补贴合同。最后的算例表明,协调是供应链竞争下的占优策略,但两条供应链均协调时的利润反而低于均不协调时的利润,即存在囚徒困境现象。     

不完备偏好扩展式博弈的序贯均衡

将Kreps和Wilson提出的序贯均衡解概念推广到了存在不完备偏好的情形.首先给出了一个修正的颤抖手完美均衡的概念,然后应用它去证明不完备偏好扩展式博弈序贯均衡的存在性.     

A capacity reservation game for suppliers with multiple blocks of capacity

This paper studies a supplier competition model in which a buyer reserves capacity from a number of suppliers that each have multiple blocks of capacity (e.g., production or power plants). The suppliers each submit a bid that specifies a reservation price and an execution price for every block, and the buyer determines what blocks to reserve. This game involves both external competition between suppliers and internal competition between blocks from each supplier. We characterize the properties of pure-strategy Nash equilibria for the game. Such equilibria may not always exist, and we provide the conditions under which they do.     

Immunity in the ABM-DSGE Framework for Preventing and Controlling Epidemics—Validation of Results

The COVID-19 pandemic has raised many questions on how to manage an epidemiological and economic crisis around the world. Since the beginning of the COVID-19 pandemic, scientists and policy makers have been asking how effective lockdowns are in preventing and controlling the spread of the virus. In the absence of vaccines, the regulators lacked any plausible alternatives. Nevertheless, after the introduction of vaccinations, to what extent the conclusions of these analyses are still valid should be considered. In this paper, we present a study on the effect of vaccinations within the dynamic stochastic general equilibrium model with an agent-based epidemic component. Thus, we validated the results regarding the need to use lockdowns as an efficient tool for preventing and controlling epidemics that were obtained in November 2020.     

Runge-Kutta stability on a Floquet problem

This work examines the stability of explicit Runge-Kutta methods applied to a certain linear ordinary differential equation with periodic coefficients. On this problem naïve use of the eigenvalues of the Jacobian results in misleading conclusions about stable behaviour. It is shown, however, that a valid analogue of the classical absolute stability theory can be developed. Further, using a suitable generalisation of the equilibrium theory of Hall [ACM Trans. on Math. Soft. 11 (1985), pp. 289–301], accurate predictions are made about the performance of modern, adaptive algorithms.Supported by the University of Dundee Research Initiatives Fund.     

Two-party competition with many constituences

The paper considers a single member district, simple plurality political system with n districts. There are two political parties, each consisting of n candidates. Individual candidates seek to win their district per se, but voters appreciate that final policy outcomes will depend upon: (1) which party wins control of the legislature, and (2) how party policy is derived from the party members' policies. Candidates take account of such voter deliberations in choosing their election strategies. A set of minimal sufficient conditions for an equilibrium to exist in this game is provided and the equilibrium characterized. While party policies are shown to converge in equilibrium, candidate policies in general do not - either across or within parties.     

烟气中Hg的氧化机理的研究

本文对Ｈｇ与Ｃｌ２在烟气中的氧化反应进行了热力平衡计算和动力学计算。平衡计算的结果表明有ＣＩ元索存在时Ｈｇ的氧化率为１００％，而在相同的条件下动力学计算纺果为Ｈｇ的氧化率在２０％～８０％之间变化，与实验结果吻合。实际的氧化反应是一种超平衡状态，不能达到理想的平衡状态。因此应采用动力学与热力平衡分析相结合的方法研究Ｈｇ在烟气中的反应机理。同时，计算结果显示Ｃｌ含量对Ｈｇ的氧化率的影响很大．     

Borel stay-in-a-set games

Consider an n-person stochastic game with Borel state space S, compact metric action sets A ₁,A ₂,,A _n , and law of motion q such that the integral under q of every bounded Borel measurable function depends measurably on the initial state x and continuously on the actions (a ₁,a ₂,,a _n ) of the players. If the payoff to each player i is 1 or 0 according to whether or not the stochastic process of states stays forever in a given Borel set G _i , then there is an -equilibrium for every >0. AMS (1991) subject classification: 60G40, 91A60, 60E15, 46A55.