不同价格模式下零售商双渠道策略研究

在考虑单一制造商与单一零售商的双渠道供应链中,采用Stackelberg博弈法,研究了集中式决策与分散式决策中渠道竞争程度与零售商和制造商的价格和利润之间的关系.研究发现竞争程度的增加对价格和各方利润具有促进作用,且在销售价格不一致的情况下,集中决策下渠道总利润比分散决策下零售商与制造商的最优利润之和更大,在实际情况中,零售商和制造商更愿意选择分散式决策.     

需求变动下双渠道供应链的竞争和协调

研究由一个制造商和一个零售商组成的双渠道供应链系统当突发事件发生时制造商和零售商之间的竞争和协调问题.通过求解优化问题的Karush-Kuhn-Tucker条件,分别给出正常情况下和突发事件发生导致需求变动时一体化双渠道供应链系统的最优定价和生产决策,并提出改进的数量折扣契约以协调突发事件发生时分散式双渠道供应链系统.结果表明需求扰动的大小和消费者对电子渠道的接受程度对双渠道供应链系统的定价、生产决策和协调契约有着重要影响,另外需求扰动量的变化幅度越大,采取应对措施前后的利润差异越大.最后通过数值分析验证了模型的有效性.     

考虑消费者环保意识的供应链决策与协调

由单一制造商与单一零售商构成的二级供应链,考虑消费者对环保产品与普通产品的偏好不同,建立供应链差别定价模型,研究制造商自身利益最大化的生产决策过程。制造商有三种生产方式,通过比较三种生产方式下的最优值发现,选择既生产环保产品又生产普通产品能使制造商和零售商获得更大的利润,所以制造商会选择两种产品都生产。在此生产方式下,分散式决策与集中式决策相比,产品零售价格升高,企业利润降低,通过设计收益共享契约可以使供应链达到协调。     

需求依赖库存量的n-2型供应链网络决策模型研究

针对n个制造商和2个零售商组成的供应链网络,假定不同制造商生产的品牌产品无差异、产品需求依赖于产品初始库存水平,并受到竞争产品库存和竞争零售商产品库存的影响,分别研究了各成员以自身利润最大化为目标进行分散式决策的带均衡约束的均衡模型、制造商主导的以品牌利润最大化为目标进行集中式决策的纳什均衡模型、以及零售商主导的以渠道利润最大化为目标进行集中式决策的纳什均衡模型,并给出了三种模式下的竞争均衡状态。结果表明,三种模式中分散式决策模式下的订购量最低,导致相应的品牌利润低于品牌利润最大化决策模式、相应的渠道利润低于渠道利润最大化模式。提出了可协调分散式供应链中零售商分别选择品牌利润最大化模式下的订购量和渠道利润最大化模式下的订购量的两种回购合同形式。数值算例表明了模型的合理性和协调合同的有效性。     

随机需求下订货权转移对供应链的影响研究

研究了市场需求随机下零售商将订货权让渡给供应商时供应商和零售商的决策问题;通过模型推导,分别得到了分散式决策下零售商的最优定价、供应商的最优订货和最优批发价格决策,以及集中式决策下供应链的最优订货定价决策;通过数值分析讨论了随机市场风险对两种情形下的市场需求和供应链绩效的影响;进一步的分析表明,当市场风险较大时,零售商将订货权让渡给供应商将能够增加供应链系统的绩效。     

基于期权合同的逆向供应链协调机制

为加强逆向供应链中制造商和回收商之间的合作关系,综合利用初始协议供货价格的稳定性和期权契约的供应弹性,建立了基于期权合同的逆向供应链利润分配模型,并与报童模型下的最优决策进行了比较.研究表明:无论在分散式决策还是集中式决策下,期权机制下的逆向供应链及其成员的最优决策均优于报童模型.通过调整期权契约参数,使得分散式决策下各成员决策与系统整体最优决策一致,而且实现了总收益在制造商和零售商之间的合理分配,达到逆向供应链的协调和帕累托最优.最后通过数值算例验证了期权合同在逆向供应链协调中的有效性,并分析了契约参数对回收商最优供货量以及双方利润的影响.     

风险规避下基于联合促销的供应链协调研究

文章针对随机需求受联合销售努力影响情形,分别在加和与乘积2种需求形式下,建立了由风险规避零售商与风险中性制造商组成的供应链协调模型,据此分析了风险规避对最优决策以及协调契约的影响。研究结果表明:2种需求形式下风险规避对销售努力的影响是不同的,在加和形式下零售商的最优订购量随着风险规避程度的增大而减少,零售商和制造商的最优促销努力却与风险规避无关;在乘积形式下零售商的最优订购量、最优促销努力以及制造商的最优促销努力均随着风险规避程度的增大而减少。此外,在加和形式下可以设计由回购契约与成本共担契约所组成的混合契约来实现供应链协调;在乘积形式下可以设计利润共享契约来实现供应链协调。     

允许有残次品和缺货的供应链模型

构建了一个有残次品、允许缺货的由单个制造商和单个零售商构成的供应链模型。研究了供应链中各成员的运作和决策。应用更新报酬定理,获得制造商和零售商的平均利润函数。证明其利润函数为凹函数,得到制造商和零售商的最优决策和最大利润。通过数值实验,对影响决策的重要参数进行了灵敏度分析。分析结果显示:当缺货成本增加时,制造商与零售商的利润都下降;价格弹性指数对制造商与零售商利润的影响明显,需要在价格和需求之间寻求一个平衡,使制造商和零售商均得以生存;次品率对制造商利润的影响更为明显。     

基于模糊需求的利润共享模型研究

在模糊需求环境下,研究了由一个制造商和一个零售商组成的供应链合作问题,分别建立了分散式和集中式2种决策模型;在集中决策下,利用利润共享机制协调双方收益,并指出双方的风险偏好与利润分配比例的关系;最后分析了需求的模糊性对订货决策的影响。     

零售商竞争下基于CVaR与收益共享契约的供应链决策模型

针对随机需求与零售商价格竞争相关,基于收益共享契约,研究一个风险中性的制造商和两个风险规避型零售商组成的供应链.通过指数乘法需求形式将价格竞争引入到需求模型中,并以CVaR作为零售商的风险度量准则,证明了竞争的零售商存在唯一最优的定价-订购联合决策,并给出了具体的解析表达式.借助于理论推导和数值分析,给出零售商的价格竞争和风险规避对供应链成员最优决策和渠道效率的影响.结果表明,收益共享契约不能完美协调此类供应链,零售商竞争有助于改善渠道效率,而零售商的风险规避降低渠道效率.     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.