Heterogeneity in Economics

This paper argues that heterogeneity of agents’ characteristics plays a fundamental role in the economy and should do so in economic models. Three aspects are considered. Firstly the notion that assuming heterogeneity was a solution to the problem posed by the results of Sonnenschein Mantel and Debreu is considered and it is suggested that the more pragmatic approach adopted by Hildenbrand is likely to be more productive. Next the role of adaptation and evolution which necessarily involve variety or heterogeneity is examined. It is suggested that heterogeneity will persist since agents will only slowly learn to adapt and that in the meantime the environment will change. Lastly the role of heterogeneity in financial markets is examined. It is suggested that heterogeneous and varying expectations may account for many of the stylised facts which do not seem to be consistent with the standard financial markets model.“Variety is the spice of life”     

集成本模型、AHP和模糊综合评判于一体的物流中心选址方法

首先建立评价指标体系，对费用指标通过成本模型的遗传算法求解，得出费用可行解，然后利用AHP计算指标体系中其他各项指标权重，综合考虑其他相关指标建立模糊综合评价体系对可行方案进行排序，得到最优方案。     

工程施工机械设备租买决策模型与准则

施工企业可以通过租赁或购买获取工程施工设备，采取何种方式应综合考虑各方案的经济合理性，风险大小，便捷和省时等，重点论述了工程施工机械设备租买决策的数学模型和相关决策准则，可供工程承包公司进行施工设备租买决策时参考。     

基于交通一体化的区域港口竞争模型

考虑了货源分布参数、道路运输成本、港口装卸效率、船舶停泊成本等影响港口竞争能力的主要因素,根据综合运输体系下区域内港口竞争的特点,建立了基于交通一体化的区域港口竞争模型。并利用竞争模型对影响港口竞争能力的内在因素进行了敏感性分析,就港口如何提高自身竞争能力进行了探索。最后,通过一个案例,说明了该竞争模型在制定港口竞争策略中应用情况。     

电子商务环境下我国第三方物流企业运作模式分析

在当今电子商务高速发展的环境下，第三方物流出现信息化、自动化、联盟化、网络化、个性化和柔性化的趋势。而建立一种与之相适应的新型第三方物流模式成了中国物流企业需要解决的问题。论文分析了电子商务对第三方物流的影响及我国第三方物流发展现状，探讨性提出了电子商务环境下我国第三方物流运作的基本模式及操作建议。     

LDSS的研究

通过分析决策支持系统的特点及作用,针对物流系统提出了物流决策支持系统结构模型,并对其功能及实现进行了探讨和研究。     

物流管理信息系统数据库设计的研究

本文在物流管理信息系统设计与开发的基础上，论速了在物流管理信息系统建设中数据库设计的重要性及其设计过程，并对于数据库设计中重要数据的安全性和完整性机制作了说明。     

A sequential model for cracking down on street markets for illicit drugs

This paper develops a sequential decision-making model for assisting law enforcement officials in allocating resources during a crackdown operation on illicit drug markets. The sequential crackdown model (SCM) considers a probabilistic framework, where the probability of incarceration of a dealer and the probability of dealing are modeled as a function of the size of a drug market, crackdown enforcement level, drug dealer's financial hardship, and other market characteristics.The model was developed and tested in consultation with enforcement officials from Philadelphia, PA and Camden, NJ. We present a detailed, step-by-step implementation scheme for updating parameters on each day of the crackdown. Parameter estimation along with examples of model usage is provided. Through these examples, we illustrate how the SCM could be helpful in understanding the response of illicit drug markets to various enforcement strategies. We further show conditions under which an alternating crackdown policy (referred to as a crackdown-backoff) or a consistent use of maximum possible enforcement would be optimal strategies for managing a drug crackdown operation. Within the context of the model and parameter estimates, we show that a much quicker and less costly collapse could be implemented if the available enforcement resources are increased. Finally, the model provides possible conditions under which a crackdown operation would be unsuccessful in eliminating a drug market.     

一种产品生产规划模型

在对供应链中运输、库存、产品生产计划分析的 基础上,提出了一种解决厂家产品生产规划的混合整数规划 模型。     

长期筹资科学化的初步探索--构建最佳资本结构模型

助计算机用定量方法快速有效的解决长期筹资决策问题是知识经济时代对企业的必然要求。最佳资本结构模型用计算机运筹学的方法来决策不同筹资方式的最优筹资额，以帮助企业实现长期筹资目标同时也是财务管理最终目标——企业价值最大化。