第一产业产值预测模型及其结构优化分析

建立第一产业产值预测模型及其内部结构优化方案,结合贵州兴义市过去几年第一产业产值及内部结构情况,预测了未来两年第一产业产值,并提出第一产业内部结构优化方案,为地方政府及有关部门调整农业产业结构,制定政策提供科学参考.     

带偏好DEA在“科学研究基金”管理中的应用研究

将带偏好锥DEA理论引入科学研究基金管理中,在包含"拥挤"迹象的生产可能集基础上建立了三个带偏好锥的平行网络结构DEA模型,对科研基金投入后产生的"成效"进行评价.这些模型分别从三个层面探讨了科研基金使用效率、分配合理性,以及最佳基金预算的确定方法.     

鱼雷追击海上目标问题的数学模型研究

在现代高科技的战争中,发射鱼雷精确地打击对方海上目标,是取得制海权的关键因素之一,本文从数学建模的角度出发,使用微分方程等建模方法,探讨了鱼雷追击敌海上目标问题,给出了相关的结论。     

品牌体验对品牌忠诚的影响机制分析——基于餐饮品牌的实证研究

本文以餐饮品牌为研究对象,探讨了包括感官体验、情感体验和关联体验三个维度的品牌体验对品牌忠诚的影响机制,基于对388份问卷数据的分析,我们发现:除感官体验维度对态度忠诚存在直接的正向影响之外,品牌体验的其他各维度对态度忠诚和行为忠诚均无直接作用;品牌体验的三个维度均可通过感知价值和顾客满意对品牌忠诚产生间接影响,其中感官体验的效应最大,其次为情感体验,关联体验相对较低。     

Portfolio selection problem with multiple risky assets under the constant elasticity of variance model

This paper focuses on the constant elasticity of variance (CEV) model for studying the utility maximization portfolio selection problem with multiple risky assets and a risk-free asset. The Hamilton-Jacobi-Bellman (HJB) equation associated with the portfolio optimization problem is established. By applying a power transform and a variable change technique, we derive the explicit solution for the constant absolute risk aversion (CARA) utility function when the elasticity coefficient is −1 or 0. In order to obtain a general optimal strategy for all values of the elasticity coefficient, we propose a model with two risky assets and one risk-free asset and solve it under a given assumption. Furthermore, we analyze the properties of the optimal strategies and discuss the effects of market parameters on the optimal strategies. Finally, a numerical simulation is presented to illustrate the similarities and differences between the results of the two models proposed in this paper.     

Permutation-induced acyclic networks for the job shop scheduling problem

In the literature of the combinatorial optimization problems, it is a commonplace to find more than one mathematical model for the same problem. The significance of a model may be measured in terms of the efficiency of the solution algorithms that can be built upon it. The purpose of this article is to present a new network model for the well known combinatorial optimization problem – the job shop scheduling problem. The new network model has similar structure as the disjunctive graph model except that it uses permutations of jobs as decision variables instead of the binary decision variables associated with the disjunctive arcs. To assess the significance of the new model, the performances of exact branch-and-bound algorithmic implementations that are based on both the new model and the disjunctive graph model are compared.     

The dynamics of an impulsive delay SI model with variable coefficients

An impulsive delayed SI model with variable coefficients and a nonlinear incidence is formulated and analyzed. By introducing three thresholds, we obtain sufficient conditions for eradication and permanence of the disease, respectively. It is shown that the conditions depend on time delay for both the global attractivity of the positive infection-free periodic solution and permanence of the model. Furthermore, our results indicate that the disease will disappear if the ratio of the maximum to minimum of the pulse vaccination rate is lager than some value. The main feature of this paper is that we introduce multi-delays and variable coefficients into the SI model, and exhibit a new method which is applied to investigate this model. Numerical results show that the system we considered has complex dynamics including periodic and quasi-periodic oscillations.     

中国FDI的混沌吸引子检测及非线性动力学预测——基于logistic模型

应用logistic模型对我国1980~2005年FDI序列进行检测,并没有发现FDI混沌吸引子存在.预测结果显示,我国FDI已趋于平稳增长,"十一五"期间FDI年均增长为3.41%,年均FDI流入量为654亿美元,预计累计吸引FDI在2978.291~3562.052亿美元之间.这为我国"十一五"利用外资规划中的目标提供了有力的支持.同时,我国FDI具有拥塞现象,且所产生的阻力日益加剧,FDI需外部激励才能持续增长.为实现"十一五"利用FDI目标,一方面我国要努力调节FDI的地区分布结构和产业分布,扩大FDI环境容量,更重要的是要保持经济持续增长,改善投资环境,提高服务质,增加外商对华直接投资的信心.     

捕食者-被捕者中含有化学计量学的离散型模型

大部分捕食者-被捕者模型是连续的,但是生物的发展未必是连续的,而且环境变化对生物的作用普遍存在时滞性.根据连续系统考虑的捕食者和被捕者的相互作用、Beverton-Holt差分方程以及化学计量学因素对系统的影响,建立了离散的捕食者-被捕者模型.分析表明:新建立的模型,基本上保留了连续系统的基本特征,揭示了能量富足的矛盾.进一步通过对全局的吸引集的构造,对模型的动力学行为有深刻的认识,还指出了生物灭绝和濒临灭绝的差别,这表明新模型比连续系统和直接利用连续解的离散方法得到的离散模型包含更多的生物意义.     

一类带有一般出生率的SIS传染病模型的全局分析

将一般出生率系数引入S IS传染病模型,得到了种群灭绝和疾病灭绝的阈值条件.分别借助S tokes定理和D u lac函数对染病者的数量模型和染病者在种群中所占比例的模型进行了讨论,得到了相应模型的全局动力学行为.