外资零售企业在华区域发展态势、战略及影响:以辽宁为例

随着我国零售业对外开放程度的不断深入,越来越多的外资零售企业进入中国市场。外资零售企业的进入为辽宁零售业的发展提供了示范作用,提高了本地零售企业的市场竞争力,丰富了市场上的零售业态类型,拉动了当地经济的发展。但是也使辽宁本地零售商业的竞争压力增大,削弱了制造商与供应商的利益,并加剧了辽宁零售业地区分布失衡的状况。在这样的背景下,辽宁本地零售企业与地方政府应积极应对,确保民族商业的健康发展。     

Competing Failure Risk Analysis Using Evidence Theory

Safety systems are important components of high-consequence systems that are intended to prevent the unintended operation of the system and thus the potentially significant negative consequences that could result from such an operation. This presentation investigates and illustrates formal procedures for assessing the uncertainty in the probability that a safety system will fail to operate as intended in an accident environment. Probability theory and evidence theory are introduced as possible mathematical structures for the representation of the epistemic uncertainty associated with the performance of safety systems, and a representation of this type is illustrated with a hypothetical safety system involving one weak link and one strong link that is exposed to a high temperature fire environment. Topics considered include (1) the nature of diffuse uncertainty information involving a system and its environment, (2) the conversion of diffuse uncertainty information into the mathematical structures associated with probability theory and evidence theory, and (3) the propagation of these uncertainty structures through a model for a safety system to obtain representations in the context of probability theory and evidence theory of the uncertainty in the probability that the safety system will fail to operate as intended. The results suggest that evidence theory provides a potentially valuable representational tool for the display of the implications of significant epistemic uncertainty in inputs to complex analyses.     

Storage constrained vendor managed inventory models with unequal shipment frequencies

We consider a supply chain where a vendor manages its multiple retailers' stocks under a vendor managed inventory (VMI) contract that specifies upper stock limits at the retailers' premises and overstock costs for exceeding those limits. We formulate a mixed integer nonlinear program that minimizes total supply chain costs and allows unequal shipment frequencies to the retailers. We develop an algorithm to solve its relaxed version which provides a lower bound cost solution. We propose a cost efficient heuristic procedure to generate delivery schedules to the retailers. We conduct a sensitivity analysis to provide insights on the performance of the proposed heuristic. Results show that our heuristic finds optimal or near optimal solutions, and it proposes substantial savings compared to the total supply-chain cost in the cases where there is no VMI and where there is VMI but with equal shipment frequencies to retailers.     

Competing Sovereignties,Contested Processes: Insights from the Venezuelan Food Sovereignty Experiment

Abstract

This article explores how ‘competing sovereignties’ are shaping the political construction of food sovereignty—broadly defined as ‘the right of peoples to healthy and culturally appropriate food produced through ecologically sound and sustainable methods, and their right to define their own food and agriculture systems'. This study was motivated by a lack of clarity on the ‘sovereignty’ of food sovereignty, as noted by numerous scholars—sovereignty for whom, and how? As there is a growing consensus that there are in fact ‘multiple sovereignties’ of food sovereignty that cut across jurisdictions and scales, there is the question of how these sovereignties are competing with each other in the attempted construction of food sovereignty. This question is becoming ever more relevant as food sovereignty is increasingly adopted into state policy at various levels, calling for state and societal actors to redefine their terms of engagement. This article explores questions of ‘competing sovereignties’ by developing an analytical framework, using the lenses of scale, geography, and institutions, and applying it to Venezuela, where for the past 15 years a food sovereignty experiment has been underway in the context of a dynamic shift in state–society relations.     

中美两国零售百强比较分析

零售百强是中美两国零售业发展的缩影,通过对中美两国零售百强的销售规模、门店数量、业态结构、店效、人效等指标的比较,得出了中国零售业处在行业生命周期的成长期,美国零售业处在行业生命周期的成熟期等结论。根据数据对比和结论分析,认为中国零售业在发展中应该以市场机制为主体、以经营能力为核心、以比较优势为关键,建立专业化和多业态经营共同发展的零售局面。     

供应商与零售商的策略机制分析

基于博弈理论模型研究不确定的短期和长期供应链中供应商和零售商的策略机制。结果表明:在短期供应链中零售商不会分享真实的预测信息,而供应商在决策时不会相信零售商的预测信息,因而短期供应链均衡是帕累托次优的;在长期供应链关系中利用特定的审查策略,预测信息被真实地传递,同时供应商会相信该信息,使最优均衡得以实现,这使供应商和零售商的境况都得到了改善。     

Exact inference for competing risks model with generalized type-I hybrid censored exponential data

Recently, exact inference under hybrid censoring scheme has attracted extensive attention in the field of reliability analysis. However, most of the authors neglect the possibility of competing risks model. This paper mainly discusses the exact likelihood inference for the analysis of generalized type-I hybrid censoring data with exponential competing failure model. Based on the maximum likelihood estimates for unknown parameters, we establish the exact conditional distribution of parameters by conditional moment generating function, and then obtain moment properties as well as exact confidence intervals (CIs) for parameters. Furthermore, approximate CIs are constructed by asymptotic distribution and bootstrap method as well. We also compare their performances with exact method through the use of Monte Carlo simulations. And finally, a real data set is analysed to illustrate the validity of all the methods developed here.     

Shared frailty model for recurrent event data with multiple causes

The topic of heterogeneity in the analysis of recurrent event data has received considerable attention recent times. Frailty models are widely employed in such situations as they allow us to model the heterogeneity through common random effect. In this paper, we introduce a shared frailty model for gap time distributions of recurrent events with multiple causes. The parameters of the model are estimated using EM algorithm. An extensive simulation study is used to assess the performance of the method. Finally, we apply the proposed model to a real-life data.     

An EM type estimation procedure for the destructive exponentially weighted Poisson regression cure model under generalized gamma lifetime

In this paper, we assume the number of competing causes to follow an exponentially weighted Poisson distribution. By assuming the initial number of competing causes can undergo destruction and that the population of interest has a cure fraction, we develop the EM algorithm for the determination of the MLEs of the model parameters of such a general cure model. This model is more flexible than the promotion time cure model and also provides an interesting and realistic interpretation of the biological mechanism of the occurrence of an event of interest. Instead of assuming a particular parametric distribution for the lifetime, we assume the lifetime to belong to the wider class of generalized gamma distribution. This allows us to carry out a model discrimination to select a parsimonious lifetime distribution that provides the best fit to the data. Within the EM framework, a two-way profile likelihood approach is proposed to estimate the shape parameters. An extensive Monte Carlo simulation study is carried out to demonstrate the performance of the proposed estimation method. Model discrimination is carried out by means of the likelihood ratio test and information-based methods. Finally, a data on melanoma is analyzed for illustrative purpose.     

Competing risks quantile regression at work: in-depth exploration of the role of public child support for the duration of maternity leave

Despite its emergence as a frequently used method for the empirical analysis of multivariate data, quantile regression is yet to become a mainstream tool for the analysis of duration data. We present a pioneering empirical study on the grounds of a competing risks quantile regression model. We use large-scale maternity duration data with multiple competing risks derived from German linked social security records to analyse how public policies are related to the length of economic inactivity of young mothers after giving birth. Our results show that the model delivers detailed insights into the distribution of transitions out of maternity leave. It is found that cumulative incidences implied by the quantile regression model differ from those implied by a proportional hazards model. To foster the use of the model, we make an R-package (cmprskQR) available.