股票市场监管策略的一个随机模型

研究了股市在一段有可能给社会造成危害的上涨行情中，管理者监管股市的问题＋根据股市的运行规律，建立了一个随机最优化模型，讨论了参数对解的影响，并得出了一些对股市监管有意义的结论．     

人力资本与教育的随机扰动模型

在一个带有生产扰动和公共支出扰动的随机模型中,把教育的产出--人力资本引入效用函数和生产函数,利用随机最优化方法,确定了最优经济增长率和最优个体教育投资率.通过分析参数,得出了最优税率.     

两国模型中的随机经济增长

本文运用随机最优化的方法 ,在两个国家的经济中建立了一个一般随机均衡模型 .得出了以下的结论 :当γ <0时 ,生产性冲击的增加能够促进经济的增长 ,但是却减少了消费 财富比率 ,当 0 <γ<1时 ,得到相反的结论 ;政府花费的扰动却能够促进经济的增长 ;消费者越看重消费 ,消费 财富比率越大 ,同时经济增长越缓慢 ;并对模型进行了福利分析和得到了世界经济增长率是两个国家经济增长率的线性组合 .     

A Note on the Discontinuity Problem in Heston's Stochastic Volatility Model

Although quasi‐analytic formulas can be derived for European‐style financial claims in Heston's stochastic volatility model, the inverse Fourier integration involved makes the calculation somewhat complicated. This challenge has puzzled practitioners for many years because most implementations of Heston's formula are not robust, even for customarily‐used Heston parameters, as time to maturity is increased. In this article, a simplified approach is proposed to solve the numerical instability problem inherent to the fundamental solution of the Heston model. Specifically, the solution does not require any additional function or a particular mechanism for most software packages or programming library routines to correctly evaluate Heston's analytics.     

一个具有时滞和阶段结构的捕食-被捕食模型

研究一个具有时滞和阶段结构的捕食者-食饵模型.通过构造适当的Lyapunov泛函,讨论了该模型的正平衡点和非负边界平衡点的全局吸引性,从而得到了保证该生态系统永久持续生存与绝灭的充分性条件.     

考虑环境污染的随机经济增长模型

本文主要考虑了环境污染对个体福利的负面效应,把环境污染水平纳入效用函数,由此建立了一个随机经济增长模型.分析了经济均衡时税收,政府环保投资,私人环保投资对经济增长率和社会福利的影响.同时还求出了最优的增长率和个人资本与财富比,消费和财富比.     

城镇职工养老保险随机模型研究

构建了包含个人、企业、政府等市场参与者相互制衡的城镇职工养老保险随机模型,该模型涉及了储蓄、工作期消费、个人养老金账户、工资、退休后消费共5个随机变量;利用ITo引理证明了随机微分方程解的存在性,唯一性,利用2010-2014年中国有关宏观数据,对5个变量进行了动态模拟,并对部分参数变动对模型的影响进行分析,得出了储蓄替代率和人口出生率与两期消费正相关,两者的小范围变动不会影响两期消费的趋势等结论.     

Filtering of a Multi-Dimension Stochastic Volatility Model

In this article, we study a stochastic volatility model for a class of risky assets. We assume that the volatilities of the assets are driven by a common state of economy, which is unobservable and represented by a hidden Markov chain. Under this hidden Markov model (HMM), we develop recursively computable filtering equations for certain functionals of the chain. Expectation maximization (EM) parameter estimation is then used. Applications to an optimal asset allocation problem with mean-variance utility are given.     

一类具有非线性传染率的阶段结构传染病模型

讨论了一类带有非线性传染率的阶段结构传染病模型,得到了各类平衡点存在的阈值条件.借助Hurwitz判据、Lasalle不变集原理和Bendixson法则,找到了疾病消除平衡点,及在无因病死亡时,地方病平衡点全局渐近稳定的充要条件.     

贪污量化的内生随机增长模型

从现实来看,贪污不是一种个人行为,是由于制度上的漏洞(如监管不严等)而产生的.本文假设贪污与廉政均衡模型服从通常的决策规则,试从量化的指标入手,分析了增大个体收入风险,加大惩贪震摄力、扩大公共开支的均衡关系及其对渎职、贪污行为的影响力.最后,给出关于抑制贪污依其影响力大小的措施的不同结论.     

Optimal Guaranteed Cost Control of Stochastic Discrete-Time Systems with States and Input Dependent Noise Under Markovian Switching

A problem of robust guaranteed cost control of stochastic discrete-time systems with parametric uncertainties under Markovian switching is considered. The control is simultaneously applied to both the random and the deterministic components of the system. The noise (the random) term depends on both the states and the control input. The jump Markovian switching is modeled by a discrete-time Markov chain and the noise or stochastic environmental disturbance is modeled by a sequence of identically independently normally distributed random variables. Using linear matrix inequalities (LMIs) approach, the robust quadratic stochastic stability is obtained. The proposed control law for this quadratic stochastic stabilization result depended on the mode of the system. This control law is developed such that the closed-loop system with a cost function has an upper bound under all admissible parameter uncertainties. The upper bound for the cost function is obtained as a minimization problem. Two numerical examples are given to demonstrate the potential of the proposed techniques and obtained results.     

人力资本投资的随机内生增长模型

本文假设人力资本是宏观经济的一部分 ,由此建立一个随机内生增长模型 ,把人力资本作为宏观经济变量并进入个人效用 .分析了经济达到均衡时个体偏好 ,不确定性对均衡增长率的影响 .同时分析了财政政策 ,税率对经济增长的影响 ,还求出了最优的增长率和人力资本投入与物质资本比 .     

公共资本投资的随机内生增长模型

本文假设公共资本是宏观经济的一部分,由此建立一个随机内生增长模型,把公共资本作为宏观经济变量并进入个人效用.分析了经济达均衡时税收,政府投资,个人投资对经济增长率和社会福利的影响.同时还求出子最优的增长率和个人资本与财富比,消费和财富比.     

Dynamic Analysis of Stochastic Spruce Budworm Differential Model with Time Delay

In this paper, we consider a stochastic spruce budworm differential model with time delay. Based on the nonnegative initial conditions, the existence and uniqueness of the global positive solution are easily found. Then, we obtain the ultimate boundedness of solution in mean under the same conditions. Furthermore, we verify that the sample Lyapunov exponent of solution is less than a positive constant. Finally, numerical examples are presented to show the consistency of the theoretical results.     

Hybrid Impulsive Control of Stochastic Systems with Multiplicative Noise Under Markovian Switching

A problem of state output feedback stabilization of discrete-time stochastic systems with multiplicative noise under Markovian switching is considered. Under some appropriate assumptions, the stability of this system under pure impulsive control is given. Further under hybrid impulsive control, the output feedback stabilization problem is investigated. The hybrid control action is formulated as a combination of the regular control along with an impulsive control action. The jump Markovian switching is modeled by a discrete-time Markov chain. The control input is simultaneously applied to both the stochastic and the deterministic terms. Sufficient conditions based on stochastic semi-definite programming and linear matrix inequalities (LMIs) for both stochastic stability and stabilization are obtained. Such a nonconvex problem is solved using the existing optimization algorithms and the nonconvex CVX package. The robustness of the stability and stabilization concepts against all admissible uncertainties are also investigated. The parameter uncertainties we consider here are norm bounded. Two examples are given to demonstrate the obtained results.     

Node Features Adjusted Stochastic Block Model

Stochastic block model (SBM) and its variants are popular models used in community detection for network data. In this article, we propose a feature-adjusted stochastic block model (FASBM) to capture the impact of node features on the network links as well as to detect the residual community structure beyond that explained by the node features. The proposed model can accommodate multiple node features and estimate the form of feature impacts from the data. Moreover, unlike many existing algorithms that are limited to binary-valued interactions, the proposed FASBM model and inference approaches are easily applied to relational data that generate from any exponential family distribution. We illustrate the methods on simulated networks and on two real-world networks: a brain network and an US air-transportation network.     

信息不对称下带有“随机压力”定价规则的连续时间模型

本文是对Back(1992)和Cho(2003)关于内部交易模型的拓展.在金融市场中一共有3类人:内部交易者,不知情交易者和做市商.考虑一类比Cho研究的模型更广的定价规则.主要用动态规划的方法,证明了当内部交易者是风险中性时,定价规则中"随机压力"消失,均衡价格还是仅依赖市场上累计交易量.相应地,本文的结论推广了Back和Cho在经典模型中的结论.     

Dynamics of the Stochastic Chemostat Model with Monod-Haldane Response Function

This paper is devoted to the asymptotic dynamics of stochastic chemostat model with Monod-Haldane response function. We first prove the existence of random attractors by means of the conjugacy method and further construct a general condition for internal structure of the random attractor, implying extinction of the species even with small noise. Moreover, we show that the attractors of Wong-Zakai approximations converges to the attractor of the stochastic chemostat model in an appropriate sense.     

具有生产性与福利性公共支出的随机内生增长模型

文章建立一个随机内生增长模型来阐明主要政策参数对经济增长与社会福利的影响.若对生产函数、效用函数、偏好及随机干扰作一些特殊的假设,我们证明了主要政策参数的均衡值能被模型参数唯一决定.进一步我们还得到了期望增长率与储蓄的清晰解.文章的最后,我们证明了政府支出直接影响个体决策者的决策:即提高经济增长率将减少福利;反之,增加福利将减少增长率.