面向钢铁企业按周交货模式的MRP安全策略研究

分析了按周交货供应波动的特点并引入了随机序列来描述供应波动。通过仿真实验研究了平均提前期波动、提前期分散度、需求突发性和安全策略等因素对钢铁企业按周交货模式下的库存费用的影响。实验结果表明安全提前期相比于安全库存量是一种更忧的安全策略。在相似的库存总最下.使用安全提前期方法的缺货量明显比使用安全库存量方法的缺货量少。     

聚集效应对安全库存的影响研究

安全库存是一种额外持有的库存，也是一种缓冲器，它对库存成本有很大影响。本文从分析供应链是怎样运用库存聚集着手，研究在不降低产品供给情况下，聚集效应是怎样影响安全库存量。     

面向随机需求的安全库存管理研究

在考虑到提前期和服务水平的情况下，针对随机需求下的安全库存问题，从定量的角度分析和研究企业应如何设置安全库存，以达到安全库存水平最优，最后以企业实际数据作出算例分析。     

基于多级库存的电网运维物资安全库存优化配置研究

针对电力公司运维物资多级库存体系与安全库存配置现状,结合安全库存聚集效应,文章提出了周转库安全库存差异聚集策略。在综合考虑库存持有成本与普通、紧急配送成本的基础上,构建了安全库存优化配置模型。通过两类电网运维物资实际数据的分析,验证了差异聚集策略下成本低于全部聚集以及全部分散策略,可以为电力公司物资集约化、差异化、精益化管理以及仓库定额配置提供依据。     

信息不完全条件下提前期可变的供应链生产库存联合优化

研究了信息不完全条件下提前期可变的单制造商-单销售商供应链生产库存联合优化,假设销售商的需求是未知分布的随机变量,提前期是订货批量的线性函数,将销售商每次的订货量、销售商的库存安全系数、制造商的每个生产周期中销售商的订货次数作为决策变量,对制造商和销售商的期望库存总成本进行联合优化,设计了优化算法,并给出了相应的算例。     

基于Arena的随机需求和随机提前期二级库存仿真优化

讨论了由一个供应商和多个经销商组成的二级库存优化问题,该系统中每个经销商的客户需求以及供应商和经销商的订货提前期都是随机的,供应商和每个经销商都采用(T,s,S)混合策略进行库存管理。首先建立了该二级库存系统优化问题的数学模型,然后设计了解决该问题的仿真流程并基于仿真软件Arena建立了仿真模型,通过对由一个供应商和三个经销商所组成的二级库存系统的仿真实验表明,利用计算机仿真方法能够很好地解决随机需求和随机提前期的二级库存系统优化问题,其所得结果更贴近实际系统。     

基于Arena的随机需求和随机提前期二级库存仿真优化

讨论了由一个供应商和多个经销商组成的二级库存优化问题,该系统中每个经销商的客户需求以及供应商和经销商的订货提前期都是随机的,供应商和每个经销商都采用(T,s,S)混合策略进行库存管理.首先建立了该二级库存系统优化问题的数学模型,然后设计了解决该问题的仿真流程并基于仿真软件Arena建立了仿真模型,通过对由一个供应商和三个经销商所组成的二级库存系统的仿真实验表明,利用计算机仿真方法能够很好地解决随机需求和随机提前期的二级库存系统优化间题,其所得结果更贴近实际系统.     

随机需求下基于提前期变化对供应链库存的优化决策

研究库存优化模型时有若干考虑因素,本文基于经济学中营销研究观,考虑随机需求下提前期的不确定与否对供应链库存优化的影响,并基于此建立缺货回补情况下的最佳订货量Q和再订货点R的库存决策优化模型。     

售后配件需求预测在供应链管理中的应用

文章首先对发动机售后配件供应链特点和供应链的订单分类进行分析,然后根据S公司通过预测模型得出的快速流动件月度需求预测数据来进行安全库存设置,并通过缩短采购间隔期和平均补货提前期来降低安全库存数而保持周期服务水平不变,对实际的售后配件管理工作有一定的指导作用。     

随机需求下基于提前期变化对供应链库存的优化决策

研究库存优化模型时有若干考虑因素，本文基于经济学中营销研究观，考虑随机需求下提前期的不确定与否对供应链库存优化的影响，并基于此建立缺货回补情况下的最佳订货量Q和再订货点R的库存决策优化模型。     

Time-varying lead–lag structure between investor sentiment and stock market

This paper uses the thermal path method to study the lead–lag structure of sentiment and the stock market. First, based on principal component analysis, four indicators are selected to construct the sentiment index. Furthermore, the effectiveness of the thermal path method is verified by numerical simulation. Finally, the lead-lag characteristics of the Shanghai Stock Index and the sentiment index are studied via the symmetric thermal optimal path method. The analysis results show that in the short term, investor sentiment has a leading position in the stock market, which may be related to the herd effect and buying the winners behavior. However, over a longer period of time, investor sentiment is affected mainly by fluctuation in the market, which may be related to the existence of cyclical fluctuations in the market and futures arbitrage. In addition, the stock market's leading effect appears mainly from January 2006 to January 2012, with an average lead time of one month.     

集中存储对安全库存影响机理研究

分析了安全库存概念及其计算方法。对分散模式的安全库存与集中模式的安全库存进行了比较,探讨了集中储存对安全库存的影响机理。指出分散模式下总安全库存和集中模式总安全库存的关系是n和!n的关系,即所谓平方根定律。     

Estimation of fractional integration under temporal aggregation

A result characterizing the effect of temporal aggregation in the frequency domain is known for arbitrary stationary processes and generalized for difference-stationary processes here. Temporal aggregation includes cumulation of flow variables as well as systematic (or skip) sampling of stock variables. Next, the aggregation result is applied to fractionally integrated processes. In particular, it is investigated whether typical frequency domain assumptions made for semiparametric estimation and inference are closed with respect to aggregation. With these findings it is spelled out, which estimators remain valid upon aggregation under which conditions on bandwidth selection.     

Neighborhood effect on stock price comovement

We investigate how the geographic distance between firms’ headquarters affects their stock price comovement. Our results show that a firm's stock return has stronger comovement with the returns of nearby firms than with those of distant firms. Being in the same state and/or in the same industry strengthens the return comovement, but does not substitute for the negative effect of geographic distance on price comovement. Firms of similar share price and size also show stronger return comovement, but these factors do not mitigate the negative distance impact. Consistent with investor home bias and neighborhood effect literature, our results suggest that investors’ preference for local stocks and their interactions lead to correlated trading in local stocks and therefore stronger local price comovement.     

Contracting on the Stock Price and Forward-Looking Performance Measures

Abstract

We examine the use of earnings, forward-looking performance measures and stock prices in managerial compensation. When the firm's owner and its manager have identical time preferences, the stock price is not useful for motivating the manager, as it is a noisy aggregation of a forward-looking measure and future earnings. In contrast, when the owner and the manager have conflicting time preferences, the noisy stock price is useful for contracting. If the manager has no access to banking and cannot trade the firm's shares, the timeliness of the stock price dominates the extra risk imposed by its noise. At the same time, forward-looking performance measures (such as customer satisfaction) can induce a desirable allocation of management effort between the short term and long term more efficiently than the stock price can. Forward-looking performance measures and the stock price are thus not direct substitutes in rewarding farsighted effort.     

I am therefore I own: Implications of organization-based identity for employee stock ownership

Most research on employee stock plan participation investigates the effects of such forms of ownership on employee attitudes, leaving our understanding of the individual differences that contribute to employee ownership largely unknown. Drawing from the consumer behavior literature, our study explores the effect of organization-based identity on the decision to participate in an employee stock purchase plan. The study was conducted in a newly public firm where we examine the effect of organization-based identity on the purchase decision in two time periods. The first point in time was the initial public offering (IPO), when the employee has little information on how the firm's stock will perform in the market. The second point in time was the first quarter following the IPO, when employees have market data to help them with decision-making. Results indicate that, as predicted, organization-based identity is associated with participation in an employee stock purchase plan, at both points in time, above and beyond the influence of several economic and psychological predictors reported in prior studies.     

The effect of cash holdings on firm performance in large Italian companies

This paper examines the relationship between cash holdings and performance in Italy over 36 years. Specifically, in light of the presence of conflicting evidence concerning the worth of cash stock, which could lead to a positive effect rather than a negative one, the role of moderating factors that can shape the magnitude of this relationship is investigated. The results show that the value of cash holdings is affected by firm‐specific characteristics, as well as factors related to the institutional context. Although other studies have analyzed moderators one at a time, this is the first work to consider how they jointly work. When the moderators are considered together, some of them become no longer statistically significant while others become even more economically and statistically relevant.