供应链中的牛鞭效应分析

牛鞭效应是指需求信息在从供应链下游传向上游的过程中发生的放大现象。这里分析了牛鞭效应可能带来的危害;具体分析了引起牛鞭效应的原因,指出牛鞭效应主要在于供应链中的信息沟通问题和供应链的一些固有的属性;最后提出了减小牛鞭效应的一些措施,指出关键在于供庆链各成员相互合作、建立起战略性伙伴关系、共享供应链中的需求信息、进行集成化供应链管理。     

供应链中牛鞭效应成因及对策研究——基于“啤酒游戏”的视角

供应链中的牛鞭效应现象严重影响企业的库存和成本,影响供应链的运作效率,减缓牛鞭效应对企业具有重要的意义。通过"啤酒游戏"实验描述了供应链中的牛鞭效应现象,根据"啤酒游戏"模拟实验过程中考虑的因素,分析牛鞭效应产生的原因,可以看到,通过信息共享、提前期压缩或JIT采购、参与人的理论决策等策略可以减缓牛鞭效应,从而提高供应链的运作效率。     

快速消费品供应链中的“牛鞭效应“分析

针对存在于快速消费品供应链中的牛鞭效应现象,从需求预测、批量定货、价格波动等方面入手,分析该效应的成因,提出通过共享信息、科学预测、库存控制、提前回款期限等方法解决快速消费品供应链牛鞭效应现象的问题.     

“啤酒游戏”在供应链管理实践教学中的应用研究

为了使学生更好地理解供应链管理课程中的需求变异放大现象,即"牛鞭效应"及其产生的原因,将"啤酒游戏"引入到供应链管理实践教学中。学生在实验中理解了"牛鞭效应"产生的原因,并提出了信息共享、压缩提前期等策略来缓解"牛鞭效应"。     

华晨宝马供应链牛鞭效应研究

牛鞭效应是供应链上的一种需求变异的放大现象,其会导致需求信息出现越来越大的波动,造成供应链服务水平下降、过多的库存投资、误导生产计划、无效运输和收益减少等损失。本文力求采用定量化方法,建立牛鞭效应量化模型,并将该模型应用于华晨宝马公司,分别对其非固定周期订货零件和固定周期订货零件进行牛鞭效应量化分析。     

需求预测对零售商期望库存水平的影响分析

研究由一个供应商和一个零售商组成的简单二级供应链系统,在假定零售商面对的市场需求服从一阶自回归模型AR(1)并且零售商采取滑动平均法对未来需求进行预测的背景下,证明了如果外界输入的白噪声服从正态分布,则零售商面对的市场需求以及发出的订货量也服从正态分布,并基于此导出了零售商的期望库存水平公式,进而给出了零售商期望库存水平和系统牛鞭效应水平之间的关系方程,解释了为什么供应链系统中牛鞭效应会引起节点企业库存大量积压的现象.     

供应链信息失真防范的目标激励机制博弈分析

由于供应链中各合作伙伴之间存在的利益目标的冲突，往往导致信息共享的低效率和信息失真现象。就信息失真问题及牛鞭效应进行了简要论述，主要就某类因机制设计而造成的信息失真问题进行了博弈论的分析和讨论，探讨了在由一个生产商和一个分销商组成的供应链中，为了防止信息失真现象的发生，生产商实行目标激励的机制，并论述生产商在什么情况下应该对经销商进行激励及其在不同的情况下应如何设计目标激励政策，来促使经销商反馈真实信息，实现双方激励的相容。     

牛鞭效应控制方法研究的新进展

牛鞭效应是需求信息沿着供应链逐级放大的现象,它是对需求信息的扭曲而产生的结果.综述了牛鞭效应控制方法研究的新进展,特别指出H∞控制方法的使用,对抑制牛鞭效应产生了较好的效果,同时还考察了文献中信息共享和信息延迟对牛鞭效应的影响.     

制造与再制造混合系统中库存与牛鞭效应的分析与优化

运用控制理论对一个简单的制造与再制造混合系统建立了动态数学模型，并定量分析了再制造过程的生产提前期和回收率对整个混合制造系统的动态特性之影响．结果表明，较高的产品回收率可以减少库存变化和牛鞭效应，回收量能够在一定程度上用于吸收需求波动，而较长的再制造提前期对于减小库存变化和牛鞭效应的作用则不明显．在该特定的系统中，供应链中有回收时的库存变化与牛鞭效应比没有回收时的要小．     

缓解供应链中“牛鞭效应”的策略研究

缓解供应链中“牛鞭效应”是实现供应链管理的关键,也是提升供应链竞争力的有效方式之一.分析了产生“牛鞭效应”的原因,论述了减少供应层级及实现需求信息共享能有效地缓解“牛鞭效应”,在此基础上提出建立基于电子商务/Internet的信息共享系统、对可定制产品采用大规模定制生产策略,能最大限度地缓解供应链中的“牛鞭效应”.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.