Modeling the role of government efforts in controlling extremism in a society

People having extreme idealogies affect the process in a region using fear of terror acts, money power, and the word of mouth communication network to change individuals to their way of thinking. This forces government to divert its limited financial resources for controlling extremism and thus affecting development. In this paper, therefore, a nonlinear mathematical model is proposed to study the dynamics of extremism governed by four dependent variables, namely, number of people in the general population having no extreme ideology, number of extreme ideologists, number of isolated ideologists (prisoners), and the cumulative density of government efforts and their interactions. The model is analyzed using the stability theory of differential equations and computer simulation. The analysis shows that if appropriate level of government efforts is applied on extremists, the spread of their ideology can be controlled in the general population. A numerical study of the model is also carried out to investigate the effects of certain parameters on the spread of extremism confirming the analytical results.Copyright © 2014 John Wiley & Sons, Ltd.     

生鲜供应链中保鲜努力投入及订货定价研究

结合生鲜损耗严重和过度保鲜双重背景,本文在区分保质期和实际有效供货时长的基础上,比较研究了由单一零售商与单一供应商构成的二级生鲜供应链中,两个主体合作与否及主导主体变化对供应链保鲜努力水平和定价的影响机制。研究表明,集中式供应链中,保鲜努力投入随新鲜度(价格)敏感性增强(减弱)而增加,而随有效供货时长增加呈倒U型;供应链的总利润也随新鲜度(价格)敏感性增强(减弱)或有效供货时长上升而增加。分散式供应链中,随新鲜度的敏感性增强,保鲜努力和总利润增加;随价格的敏感性增强,保鲜努力增加而总利润减小;而随有效供货时长上升,保鲜努力先增大后减小,总利润增加。分散式供应链存有搭便车的机会,但因有效供货时长占保质期比例不同,自身投入保鲜努力可能比搭便车更有利。     

风险投资合约中最优努力与收益分享比的关系

构建了多阶段风险投资的委托代理模型,同时考虑了投资家和企业家两方面的努力,对企业家和投资家的最优努力水平与收益分享系数的关系进行了理论分析和数值模拟,随后考虑了企业家公平偏好对努力水平的影响.发现随着互补程度的增大,两者努力水平对分享系数的反应曲线趋于重合.公平偏好的加入使得投资家和企业家对自身收益更加敏感.     

考虑运输时间和消费者偏好的水产品供应链协调研究

本文研究了由一个供应商和一个零售商组成的两级生鲜品供应链协调问题。考虑消费者水产品生鲜偏好、运输时间和保鲜努力水平等影响因素,分别构建了集中决策和分散决策下冷链保鲜存储的零售商和供应商的供应链成员之间Stackelberg博弈模型。通过理论证明和数值仿真的研究表明,在“保鲜成本分担+收益共享”契约,供应链总体利润大于一般保鲜成本共担契约,能获得更高的利润,“保鲜成本分担+收益共享”契约更能提高冷链储存的保鲜努力水平。     

零售商双渠道供应链的定价与协调机制研究

主要研究了一个建立线上线下双渠道的零售商,如何进行定价协调零售商线上线下的水平冲突,并最终到达零售商整体的利润的优化.根据实际情况引入了销售努力补偿的协调机制,并通过算例分析发现当零售商对其网络渠道提供合适的销售努力程度时,零售商的利润可以得到优化.并在双渠道的零售商实现水平协调的基础上,考虑供应链垂直方向上因零售商和制造商双方博弈下带来了双重边际效应,进一步设计了收入共享契约,研究表明当零售商提供合适的收入分配比时,可以实现制造商和零售商利润的优化,实现了供应链成员Pareto改进,这样零售商双渠道就实现了水平和垂直方向的全协调,供应链成员的利润得到了优化.     

Periodicity of pricing and marketing efforts in a distribution channel

Most research about cooperative (coop) advertising programs in channels relies on the assumption that manufacturers and retailers decide of pricing and marketing efforts simultaneously. This paper evaluates this central assumption and investigates the optimal periodicity (sequence of move) of pricing and marketing efforts (ME) decisions for a distribution channel. We develop a game theoretic model that accounts for pricing at each level of the channel, for the manufacturer’s ME mix strategies (a direct ME to consumers and coop advertising program offered to the retailer) and the retailer’s ME as well. We obtain solutions for a bilateral channel under different vertical interaction scenarios; when the channel is led by the manufacturer, the retailer or when channel members decide simultaneously of each of their marketing mix decisions (vertical Nash). We compare the effect of pricing and ME decision periodicity on outputs for each channel member. The main findings suggest that simultaneous decision-making of pricing and ME is optimal only for high enough levels of the manufacturer’s ME effects. For very highly effective marketing efforts, sequential play of pricing and ME allows channel members to implement equilibrium strategies and achieve maximum profits that would not be achieved with simultaneous decision-making. This highlights the importance of relaxing the simultaneous play assumption of pricing and ME in a distribution channel.     

考虑零售商保鲜和消费者效用的生鲜农产品供应链协调

针对消费者对生鲜农产品新鲜度要求更高但零售商单独保鲜能力有限的问题,从提高消费效用角度出发,构建了受生鲜农产品新鲜度和价格影响的消费者时变效用函数,建立了由零售商和供应商组成的两级生鲜农产品供应链利润模型,采用Stackberg博弈方法分析了分散式决策下供应商的最优保鲜努力和零售商的最优定价,并同集中式决策下供应链系统的最优决策进行比较。由于分散式决策下零售商的保鲜努力较小,因此给出了能够实现生鲜农产品供应链协调的“保鲜成本分担+收益共享”契约。在此基础上,以同时实现供应链协调和提高消费者整体效用为目标,进一步确定了协调契约所在的区间范围。最后通过算例证明了协调契约的有效性。     

考虑促销努力与生产努力的供应链召回努力策略研究

考虑一条由单个供应商和单个制造商组成的二级供应链,面对产品召回事件,供应商和制造商都可以通过召回努力来降低召回事件发生的概率。本文研究了供应链最优召回努力策略,研究发现双方的召回努力与初始期望单位召回成本和潜在市场规模有关。当潜在市场规模和初始期望单位召回成本都较小时,双方均选择部分召回努力,当潜在市场规模和初始期望单位召回成本都较大时,双方均选择全部召回努力,否则,供应商选择全额召回努力而制造商选择部分召回努力。由于制造商的促销努力与供应商的生产努力是企业扩大市场规模常用的策略,因此,本文还研究了这两种策略分别对供应链召回努力策略的影响。我们发现这两种策略都能降低双方采取全额召回努力时潜在市场规模的门槛,激励双方增加召回努力,降低产品召回概率并增加供应链成员的利润。特别的,我们还对比了这两种策略对双方召回努力的影响,发现当促销努力成本系数与生产努力成本系数都较小时,两种策略对召回努力的影响相同,当生产努力成本系数足够大时,考虑促销努力时双方的召回努力水平更高,否则,考虑生产努力时双方的召回努力水平更高。     

供需不确定条件下考虑双边努力的供应链组合契约设计

本文研究供需同时不确定条件下考虑双边努力的供应链契约设计问题,在一个供应商和一个零售商组成的二级供应链系统中,供应商的努力影响产量的不确定性,零售商的努力影响市场需求的不确定性。首先,利用Stackerberg主从博弈模型计算了分散决策时零售商、供应商的最优期望利润,并将计算结果与集中决策时供应链整体的最优期望利润进行对比。由于双重边际效应的存在,分散决策时供应链的最优期望利润小于集中决策时供应链的最优期望利润。基于此,本文设计了回购和成本分担组合契约来协调该供应链,计算了回购价格和成本分担系数的表达式,得到了回购和成本分担契约下供应商和零售商的最优期望利润。结果表明,在特定条件下,该组合契约不仅可以协调供应链,还可以实现供应链利润的任意分配。最后,通过数值计算,分析了供需双方的决策变量和期望利润随契约参数的变化情况。     

Coordination of cooperative cost-reduction efforts in a supply chain partnership

We study cooperative cost reduction in a decentralized supply chain with a single manufacturer and multiple suppliers. The manufacturer assembles components that are procured from the suppliers to produce a final product. Both the manufacturer and the suppliers invest in reducing the unit production costs of the components. We see that neither of the two well-known conventional contracts, the wholesale price contract and the cost-plus pricing contract, generally coordinates the supply chain, i.e., under both of these types of contract, the individual optimal cost-reduction efforts of players deviate from the centralized system-optimal solution. However, this result is not surprising because these contracts encourage either only the manufacturer or only the suppliers alone to invest in cost reduction.