耐用品市场企业租售策略研究

在耐用品垄断厂商同时生产耐用产品和易耗部件的前提下,建立了耐用品和易耗部件的有关耐用度的两期需求-价格模型.通过模型可以发现存在租赁的耐用品生产者将会在成本最小化的基础上生产社会效用较高的耐用品,而为了追求更多的利润他们会只考虑降低易耗部件的使用寿命,从而验证了Swan的市场独立化的结论时于生产易耗部件的耐用品租赁者是成立的.然而,对于耐用品的销售市场,Swan的市场独立化结论不再成立.耐用品垄断企业会采取计划废弃的策略,在不同程度上生产耐屯用度较低的耐用品及其易耗部件.在易耗部件使用寿命相对很高时,耐用品垄断企业会最大化其计划废弃策略.     

耐用品及其易耗部件耐用度对双寡头企业均衡产量的影响研究

为了研究耐用品双寡头企业的竞争策略,基于Bulow的耐用度选择模型,建立了存在易耗部件情况下的双寡头耐用品企业两期需求一价格模型;求得了双寡头耐用品企业租赁情况下的两期均衡产量;并运用MATLAB软件对均衡解进行仿真,分析了双寡头耐用品企业自身和对手的耐用品耐用度及易耗部件耐用度对均衡产量影响。     

厂商在市场需求及预测不确定下的多期定价研究

建立多阶段线性需求-价格模型,运用动态规划思想,针对耐用品市场需求量不确定及耐用品生产厂商市场信息预测不准的问题展开探讨.得到了如果消费者对耐用品价格的预期与耐用品生产厂商对市场的预期不一致,耐用品需求量的波动及厂商掌握信息量的多少将对耐用品生产厂商的最优定价具有影响等结论.并根据现实市场状况,对信息不对称下的耐用品定价模型的经济含艾给予分析,结果表明模型对耐用品生产厂商的市场决策具有理论指导意义.     

企业在市场需求及预测不确定下的多期定价研究

建立多阶段线性需求一价格模型,运用动态规划思想,针对耐用品市场需求量不确定及耐用品生产厂商市场信息预测不准的问题展开探讨。得到了如果消费者对耐用品价格的预期与耐用品生产厂商对市场的预期不一致,耐用品需求量的波动及厂商掌握信息量的多少将对耐用品生产厂商的最优定价具有影响等结论。并根据现实市场状况,对信息不对称下的耐用品定价模型的经济含义给予分析,结果表明模型对耐用品生产厂商的市场决策具有理论指导意义。     

群体理论视角下消费者参与程度研究

群体因素在研究消费者行为中的参与活动及其参与水平时非常重要。本文从实证角度验证了群体理论对消费者参与程度的影响。通过对283名参与过群体活动的消费者进行调查,根据SPSS和LISREL的因子分析和结构方程分析结果可以得出结论:群体因素对消费者参与有着明显的影响,其中包括社会助长作用、去个体化、群体极化、群体规范、从众等因素。同时,群体因素会对消费者参与俱乐部等群体消费行为产生显著影响。     

人体行走下肢生物力学研究

采用运动图像采集系统、测力系统,获得人体行走过程中关节标记点坐标值及脚底力的变化信息,结合人体动力学模型,研究了不同负重（0,10,20,30kg）及不同行走速度（0.8,1.3,1.7m/s）对人体下肢运动学及动力学的影响.在人体行走矢状面内有下述研究结果.1）负重对人体行走运动学的影响为：踝关节在脚尖离地阶段的关节伸展角度随着负重增加而增加;膝关节的运动范围随着负重增加而减小;髋关节前屈角度随着负重的增加而增加,相反的髋关节的伸展角度随着负重的增加而减小.2）速度对人体行走运动学的影响为：踝关节运动范围随着速度增加而增加;膝关节最大伸展角度随着速度增加而增加;髋关节弯曲角及伸展角均随速度的增加而增加,且髋关节运动范围也随速度的增加而增加.3）负重及速度对人体行走动力学的影响为：踝关节、膝关节、髋关节力矩及功率均随负重、速度的增加而增加.研究结果可为人体下肢助力行走外骨骼机器人的设计与研究提供参考依据.     

柔性收益管理模型:基于实物期权的新视角

以企业的容量控制决策为例,尝试从实物期权理论的新视角来研究不确定条件下企业收益管理(RM)问题,建立了一个柔性RM模型,以此来填补实物期权在此方面应用研究的空白和不足。求出了最佳容量投资时机和最优容量控制规模,在此基础上利用比较静态分析和模拟分析进一步探讨了风险对容量控制决策的影响规律。研究发现,在容量控制规模和投资期限既定的条件下,最佳容量投资时机随风险的增强而逐渐推迟,且最优容量控制规模随风险的增加呈现递增的趋势;企业存在过度投资行为。     

全球热点研究活动领域分析

<正>2018年12月,日本科技政策研究所(NISTEP)发布研究报告,基于科学地图对全球热点研究活动进行可视化分析。主要结果如下:1)全球科学研究覆盖领域持续扩展科学研究在相互影响的同时不断发展,所覆盖的研究领域持续扩展,数量由2002年的598个增长到2016年的895个,增长率约50%。主要贡献来自全球各国论文数量的增加,中国等新参与者的加入扩大了研究人员的交流范围,并促进了新研究领域的出现和现有研究领域的分化。2)全球研究     

基于古诺模型的风火电合作容量优化

在风火打捆直流外送系统中,送端电网的风电场和火电厂属于不同的利益主体,二者对电源容量的规划存在相互影响.在电力市场环境下,考虑我国现有的可再生能源政策以及风电场和火电机组的实际运行特性,基于博弈理论分别建立了风力发电商和火力发电商之间,采取合作与不合作两种策略下的利润模型,来模拟风火发电商的决策行为.当二者采取不合作策略时,以各自利润最大化为目标,建立古诺博弈模型,得到双方通过预估对手的反应策略规划各自容量,使己方获得最大利润的Nash均衡解;当二者均采取合作策略进行容量规划时,以双方总利润最大化为目标,求取该方式下的最优规划容量,根据己方策略变化给对方利润产生的变动定义了影响系数,并据此给出了二者的利润分配方案.应用该方法对一个算例进行了计算分析,得出在风火打捆外送系统中,风力发电商在博弈中处于主动地位,火力发电商处于被动地位的结论.研究工作及成果可作为参与新能源电源规划各方决策的依据.     

岷江源头区森林景观动态与土壤侵蚀的关系

为了解岷江源头区森林经过变迁对土壤侵蚀的影响,利用遥感和GIS技术分析了岷江源头区的森林景观动态(1974～2002年),应用USLE模型计算该区域同时期的土壤侵蚀变化.近30年来,随着森林景观面积的持续增加,土壤侵蚀量逐渐减少,各景观类型的散布指数也随着土壤侵蚀量的减少而增加.各不同的森林景观控制土壤侵蚀的能力存在差异,针叶林最优,阔叶林次之,针阔混交林最差.森林景观破碎度随土壤侵蚀的增长而增加,分布在较轻侵蚀区中的景观斑块具有更复杂的形状.     

Which survey indicators are useful for monitoring consumption? Evidence from European countries

This paper assesses the information content of two survey indicators for consumption developments in the near future for eight European countries in the period 1985–1998. Empirical work on this topic typically focuses on consumer confidence, the perceptions of buyers of consumption goods. This paper examines whether perceptions of sellers of consumption goods, measured by retail trade surveys, may also improve short‐term monitoring of consumption. We find that both consumer confidence and retailer confidence embody valuable information, when analysed in isolation. For France, Italy and Spain we conclude that adding retail confidence does not improve the indicator model once consumer confidence has been included. For the UK the reverse case is obtained. For the remaining four countries we show that combining consumer sentiment and retail trade confidence into a composite indicator leads to optimal results. Our results suggest that incorporating information from retail trade surveys may offer significant benefits for the analysis of short‐term prospects of consumption. Copyright © 2004 John Wiley & Sons, Ltd.     

Forecasting private consumption with Google Trends data

This paper examines the predictive relationship of consumption‐related and news‐related Google Trends data to changes in private consumption in the USA. The results suggest that (1) Google Trends‐augmented models provide additional information about consumption over and above survey‐based consumer sentiment indicators, (2) consumption‐related Google Trends data provide information about pre‐consumption research trends, (3) news‐related Google Trends data provide information about changes in durable goods consumption, and (4) the combination of news and consumption‐related data significantly improves forecasting models. We demonstrate that applying these insights improves forecasts of private consumption growth over forecasts that do not utilize Google Trends data and over forecasts that use Google Trends data, but do not take into account the specific ways in which it informs forecasts.     

Diffusion of new products in risk-sensitive markets

Diffusion of new products may be deterred by consumers' uncertainties about how they will perform. This paper introduces a decision-theoretic framework for modeling the diffusion of consumables, in which consumers choose between a current and new product so as to maximize expected utility. Consumers that are sufficiently risk-averse delay adoption, and change their prior uncertainties in a Bayesian fashion using information generated by early adopters. Under certain assumptions about the underlying consumer choice process and the market dynamics, the result is logistic growth in the share of consumers that choose the new product. The model can be generalized by allowing for consumer heterogeneity with respect to performance of the new product. The paper concludes with a discussion of applications for market forecasting, design of market trials and other extensions.     

Forecasting new product trial in a controlled test market environment

A number of researchers have developed models that use test market data to generate forecasts of a new product's performance. However, most of these models have ignored the effects of marketing covariates. In this paper we examine what impact these covariates have on a model's forecasting performance and explore whether their presence enables us to reduce the length of the model calibration period (i.e. shorten the duration of the test market). We develop from first principles a set of models that enable us to systematically explore the impact of various model ‘components’ on forecasting performance. Furthermore, we also explore the impact of the length of the test market on forecasting performance. We find that it is critically important to capture consumer heterogeneity, and that the inclusion of covariate effects can improve forecast accuracy, especially for models calibrated on fewer than 20 weeks of data. Copyright © 2003 John Wiley & Sons, Ltd.     

帕金森病的非运动症状——疲劳

帕金森病一直被认为是以运动障碍为主的疾病,近年来其非运动症状越来越备受关注。本文仅就帕金森病中的疲劳这一个非运动症状的定义、流行病学、影响因素、评价量表和治疗做一综述。