Disaggregation and consolidation of imperfect quality shipments in an extended EPQ model

We consider a standard economic production quantity (EPQ) model. Due to manufacturing variability, a fraction P of the produced inventory will have imperfect quality, where P is a random variable with a known distribution. We consider a 100% inspection policy and further assume that the inspection rate is larger than that of production. Thus, all imperfect quality items will be detected by the end of the production cycle. For such an augmented EPQ model, we first derive the new optimal production quantity assuming that the imperfect quality items are salvaged once at the end of every production cycle. Then, we extend this base model to allow for disaggregating the shipments of imperfect quality items during a single production run. Finally, we consider aggregating (or consolidating) the shipments of imperfect items over multiple production runs. Under both scenarios we derive closed-form expressions for both the economic production quantity and the batching policy, and show that our desegregation/consolidation schemes can lead to significant cost savings over the base model.     

基于AHP-FCE的氯碱化工园区循环经济评价研究

结合氯碱化工园区的实际情况,建立了氯碱化工园区循环经济评价指标体系,运用层次分析法(analytical hierarchy process,AHP)确定了指标体系中各指标的权重,运用模糊综合评判(fuzzy com prehensive evaluation,FCE)理论,建立了氯碱化工园区循环经济综合评价模型,并将这一模型应用于某氯碱化工园区循环经济的综合评价。实例表明:模糊综合评价方法可操作性强,可在氯碱化工园区循环经济综合评价中广泛应用。     

所有权与自然垄断产业规制——组合模式及选择

对于自然垄断产业采用何种所有权结构的规制模式,在理论研究与实践操作中都存在着多样化的选择。本文主要比较分析了民营外生规制、国有内生规制和混合所有权规制三种不同组合模式,并认为混合所有权规制模式较好地兼容了其他模式的优点,可以成为自然垄断产业改革与治理进程中的一个可取路径。欧盟国家自然垄断产业的改革经验,从实践上证明了混合所有权规制模式的可行性,尽管其也存在一定的局限性。同时,本文认为对于转型改革时期的中国,针对自然垄断行业的国有企业,可以考虑采用混合所有权规制模式的改革路径,通过股权开放的形式放松民营资本进入自然垄断产业的行业管制,并有效、平稳地建立起自然垄断产业规制体系。     

Regulation and competition in the European mobile communications industry: An examination of the implementation of mobile number portability

Over the past two decades, the mobile communications industry has seen a considerable drop in the consumer switching charges made by service providers in order to promote effective competition and ensure a level playing field for new market entrants. Mobile Number Portability (MNP) is an important regulatory measure taken to reduce switching costs, and it is believed to play an important role in fostering competition in the mobile market. MNP implementation has varied significantly across European Union countries, particularly with respect to porting time and customer fees, both of which are important factors when deciding whether to switch to another provider. The research examines the effects of MNP implementation on competition in the European mobile communications industry. The study findings indicate that subscriber churn rates are negatively affected by both the level of charges levied on subscribers wishing to maintain their current number (porting) when switching mobile providers and the length of time required to switch. The implications of the effectiveness of MNP regulation for competition in the mobile communications industry are discussed.     

The informational relevance of corporate social responsibility: evidence from DS400 index reconstitutions

This study examines the relationship between corporate social responsibility and financial performance by analyzing the intra‐industry wealth impact of additions and deletions to the Domini Social 400 index. Results from the event study analysis indicate that additions to the index generate a positive share price response for the announcement firm and a negative response by rival firms. The opposite reaction is observed for index deletions. Additionally, the share price response is more pronounced for informationally opaque industries. Our study highlights the importance of external monitoring agencies in providing meaningful information that helps resolve investor uncertainty regarding the quality of a firm's relationships with its primary stakeholders. Copyright © 2011 John Wiley & Sons, Ltd.     

Technological development at the boundaries of the firm: a knowledge‐based examination in drug development

This paper examines how the knowledge‐based view (KBV) can be applied to firm boundary decisions and the performance implications of those decisions. At the center of the paper is a theoretical and empirical examination of how firms most efficiently organize for technological development. We find that distinct organization approaches are advantaged in the speed of technological development depending on the structure of technological development problems and the depth of firms' technological area experience. We make theoretical and empirical contributions to KBV research that examines knowledge development and transfer. Drug development in the pharmaceutical industry serves as our empirical setting. Copyright © 2012 John Wiley & Sons, Ltd.     

基于LCC理论的输电线路绝缘子选型研究

对于如何将全寿命周期成本（1ifecyclecost,LCC）管理应用于输电线路绝缘子选型的方案评价,目前的研究尚不多。结合各种类型绝缘子的运行性能及特点,以LCC理论为基础,对输电线路绝缘子全寿命周期内的各种成本进行分解计入,提出了输电线路绝缘子的全寿命周期成本模型,并对该成本模型进行LCC分析和LCC评价,建立起针对绝缘子选型的一整套LCC评价体系。然后结合某220kV输电线路绝缘子选型的实例,研究了LCC评价体系在输电线路绝缘子选型决策中的应用。通过对3种方案的比较分析,得出了输电线路绝缘子选型的技术经济综合最优方案。     

分布式能源站的能源综合利用及噪音治理

分析了广州大学城分布式能源站（简称大学城能源站）一期项目采用2×78Mw燃气-蒸汽联合循环机组的能源利用效率状况;介绍了大学城能源站能源综合利用的成效与噪音环境治理的措施,并对天然气分布式能源系统发展方向提出了合理化建议。该项目可为我国分布式能源发展积累经验,为合理利用天然气资源、提高能源利用效率及智能电网建设支撑提供示范和推动作用。     

基于SEM的企业国际化经营与绩效关系研究

本文分析了我国上市公司国际化经营程度与企业绩效间的关系,探讨了国际化经营程度对企业绩效的影响程度。通过对深沪A股410个样本企业的分析,本文尝试构建结构方程模型（SEM）以验证中国企业国际化经营与企业绩效之间的路径关系,估计国际化经营对绩效的影响程度。结构方程模型估计结果表明,中国上市公司的规模经济效率对其短期绩效有正向影响,企业的全球协同效率对其长期绩效有正向影响。     

基于PCA-ESDA的中国省域旅游经济时空差异分析

以中国大陆31个省级区域为研究单元,选取1999—2008年反映旅游经济的相关指标,利用SPSS16.0软件对数据进行主成分分析,计算出每个省份旅游经济的综合得分,然后对综合得分进行空间自相关分析。结果表明:中国旅游经济的发展水平总体上呈现从"长三角"及"珠三角"向内陆逐渐降低的特征。1999—2008年中国旅游经济发展全局空间自相关不显著,但局部空间自相关却表现出一定的规律性:沿海省份位于HH区,西部省份位于LL区,西南、部分东部和中部省份位于LH区和HL区。中国省域旅游经济发展呈现出一种持续的非均衡态势,1999—2008年中国省域旅游经济的总体空间格局并没有发生根本性的变化。省域旅游经济集聚的空间依赖性、省域经济发展水平、区位与资源禀赋、政府政策是影响中国省域旅游经济空间差异的主要原因。