运用极大熵准则求解面临不确定型决策的报童问题

本文运用极大熵准则求解了面临不确定型决策的报童问题。利用变分法对极大熵准则进行求解,从而将不确定型决策问题转化为风险型决策问题。在风险中性假设下,构建了报童问题的期望利润最大化模型,并得出其最优订购量。最后,通过算例分析说明在不同先验信息下报童问题的不同最优决策。     

带 有 预 算 费 用 约 束 的 报 童 模 型

讨论带有预算费用约束的报童问题. 建立了带有一般费用约束、 缺货预算费用约束、 商品处理预算费用约束的3种模型, 分别求出了最优解, 并进行了模型的灵敏度分析.     

冲突调解策略的研究

研究了多人冲突的调解问题,在各冲突人之间引入约束条件,冲突各方在满足约束条件下进行决策,从而形成消除冲突的调解方法.文中分析了约束条件(调解策略)存在的条件,提出了约束条件(调解策略)的设计方法,并对单目标和多目标冲突决策问题进行了研究.     

需求具有价格敏感性的多产品报童问题研究

对需求具有价格敏感性的多产品报童问题进行定量研究。首先建立了期望收益最大化为目标。需求函数是线性加函数形式,具有预算约束的多产品报童模型。接着证明了在需求分布函数具有失效率递增性质的条件下边际预算利润是产品订购量的非增函数,指出该模型是一类凸可分非线性连续多产品资源分配问题,可以应用二分搜索算法获得最优解或者近似最优解。最后应用算例验证了算法和模型的有效性。     

带有预算费用约束的多地点报童模型

有针对性地研究了一种带有预算费用约束的多地点(连锁店)报童问题。在各地需求变量均服从正态分布的情况下,建立了数学模型,利用最优化方法进行了求解,并对模型的灵敏度进行了分析。     

价格敏感需求下零售商的最优定价策略

研究单个零售商单个制造商的二级供应链的经典报童模型,考虑单周期下报童模型的联合最优定价-订购决策.分析了需求随机且价格敏感情况下系统的最优价格,给出了最优决策的存在性的充分条件.区别于以往相关的研究,假设需求函数是更一般化的加乘型需求函数.在一些合理的假设下,保证随机需求情况下零售商的期望利润函数是对数凸的.证明了由于需求除价格外随机扰动的存在,零售商的期望收益总是小于仅受价格影响时可获得的确定性收益.另外,假设需求的期望具有递增的价格弹性,可以保证仅受价格影响时可获得的确定性收益函数是拟凸的.本结论可以延伸到带有缺货惩罚的单周期报童模型的联合最优定价-订购决策问题,在理论上更具有一般性,对研究多零售商的价格竞争决策问题和供应链契约协调等问题提供了重要理论依据.     

一次订购季节性销售的一种扩展报童模型

讨论在一种特殊缺货水平约束下的扩展报童问题, 指出购买者必须同时决定最佳订购时间和最佳订购量. 建立了特殊缺货水平约束下的扩展报童问题的数学模型, 求出了最优解, 并进行了灵敏度分析.     

基于2个不相关的不确定因素的一次性决策理论研究

针对决策问题中出现的多个不确定因素,研究2个不相关的不确定因素的一次性决策问题.在单一不确定因素的一次性决策基础上,首先得出2个不确定因素的可能性,然后提出焦点和最优方案的选择方法,给出2个不相关的不确定因素的一次性决策过程,最后以报纸经销商问题为例说明这样的决策过程.分析的结果表明提出的决策模型能够帮助决策者在2个不确定因素的情形下找出最优方案.     

双周期带服务水平约束的报童模型决策分析

研究报童模型双周期下决策者面临服务水平的机会约束时,所做出的最优决策.通过构建模型,分析了该模型的最优订货决策和最优目标函数的解析解.在数值分析中,对模型中的参数做了相应的灵敏度分析.最后,将该模型和文献中的单周期带服务水平约束的报童模型进行了对比.分析了在2种不同的模型下,参数变化给模型的目标值和最优解带来的影响.     

三角分布下可追加订购的报童问题最优解

在经典报童问题中，订购是一次性的，这容易导致供货服务水平与无缺货风险贮存成本之间的矛盾。笔者研究可追加订购的报童问题，把收益作为目标函数，在追加订购数量有限制的条件下，建立了数学模型在假设需求满足三角分布下，讨论了最优解的具体求法。     

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).     

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.     

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.