基于聚类-重心法和CFLP法的两级物流配送中心选址

为了确保物流配送中心选址的合理性,节约配送里程,降低配送的费用成本,将聚类-重心法和CFLP（Capacitated Facility Location Problem）模型结合起来来对城市的物流配送中心选址进行研究。首先,用最短距离聚类法进行配送区域划分;其次,通过CFLP模型结合聚类结果,以物流配送成本费用最小化原则选出二级物流配送中心;再次,分别对二级物流配送中心和城市中所有的区域物流配送中心使用重心法求出2个一级物流配送中心的坐标;最后,分别计算出2个一级配送中心的配送总距离和配送总费用,并进行对比分析。结果表明：选择通过对二级物流配送中心使用重心法求出的一级物流配送中心作为最终一级物流配送中心最为合理。该方法能应用到两级物流的配送中心选址过程中。     

基于双层规划模型的配送中心选址问题研究

配送是物流的核心问题,配送中心的选址问题直影响物流成本的控制。建立双层规划模型,应用遗传算法求解,将配送中心选址涉及到的选址规划者和客户两个具有明显不同目标的决策者联系起来,还考虑到配送中心建成后遇到的竞争问题,从而使配送中心选址模型更具有实际意义和指导作用。     

军事物流配送中心选址模型及其优化算法

配送中心选址在军事物流中具有重要的意义，本文基于军事物流自身的特点，建立了时间优先的单配送中心选址模型、时间优先的多配送中心选址模型和成本优先的多配送中心选址模型三种模型，对于前两种模型采用了分步骤迭代的优化解法，而对于第三种模型采用了图论中的最短路径算法进行优化求解，这些对军事物流理论的研究都必将具有参考价值。     

共同配送选址-路径优化模型与算法

以北京市奶制品配送问题为场景,研究了共同配送选址-路径优化问题。建立了两层级带容量约束的共同配送选址-路径问题的混合整数规划模型,设计了求解模型的三阶段算法。第一阶段采用基于遗传算法的带容量限制的K-means聚类方法,将客户划分为若干客户集;第二阶段计算每个备选配送中心为每个客户集提供服务的最优配送路径及成本,在此基础上将共同配送中心选址与第二层级配送路径优化问题简化为配送中心选址和客户集分配问题,建立数学模型并利用Lingo软件求解;第三阶段确定从物流中心到共同配送中心的最优配送路径。通过对比两大品牌奶制品在北京地区各商超的单独配送与共同配送成本,验证了模型和算法的合理性和有效性。研究结果为解决不同类型产品共同配送网络优化等问题提供了决策依据。     

区域性煤炭运输节点的优化

针对当前我国煤炭行业物流诸多现实问题,尤其是煤炭运输通道规划合理化问题,通过对煤炭物流客户的需求量、运输距离及多式联运等信息的分析,并在对煤炭配送中心选址的重要性、合理性及其煤炭调运成本的影响因素的研究之后,文中运用煤炭配送中心合理的选址优化模型与配送成本优化模型等优化方法,实现煤炭运输成本最小化,以达到优化区域性煤炭运输节点的目的。煤炭配送中心合理的选址优化模型与配送成本优化模型的科学性和有效性也经过实验证明其应用的实际价值,为我国煤炭运输通道合理化的建设提供理论和技术支持,也有为我国煤炭运输通道的未来发展提供了指导性的意义。     

免疫算法在带权值的物流配送中心选址中的应用

针对物流配送中心选址问题中很少考虑时间因素的问题,提出将配送时间与需求量共同来决定权值的选址模型,使用免疫算法求解带权值的物流配送中心选址问题,并说明了所提出算法具有全局渐近收敛性。通过实例仿真,与不考虑配送时间因素相比,用所提出的模型得到的结果具有更少的最短距离之和(约少了12.68%)以及更少的运行时间,最佳迭代次数约为不考虑配送时间因素下的1/4,从而论证了所提出模型的合理性及有效性。
     

一个物流配送中心选址模型及其算法

一个最优的配送中心选址方案,既可以提高物流系统的效率,又能降低物流系统的成本.在时间已经成为竞争优势的一种新资源的社会,将时间约束考虑到配送中心选址模型中无疑是一个突破.建立了一个物流配送中心选址模型,在模型中只需要知道所需配送中心的个数上限即可,松弛了以往模型中需确定所需配送中心个数的条件.模型求解算法上,采用优化方法中的0-1规划割平面法,结果表明模型具有可靠性,且计算复杂度得到降低.     

模糊需求环境下的网络选址及规划分析

在需求充满不确定性,成本结构复杂的现实情况下,已知工厂和顾客的地理位置,如何从初步拟定的候选点中选择配送中心的建设位置,同时规划配送中心与顾客的配送关系,是公司决策中经常碰到的一个问题。为解决这一问题,建立了在模糊需求环境下,整体考虑与选址相关的各项成本,如库存、运输、仓库固定成本与内部搬运成本等的三级物流网络选址模型,并进而利用模糊数学领域的可信性理论,对模型进行了优化整理,得到了同解模型。指出了同解模型是整数规划问题的解法。     

福建省农产品物流配送中心选址问题研究

农产品由于其自身的生物特性,导致其物流成本居高不下,买难卖难矛盾突出。提高农产品物流效益,减少农产品在流通过程中的不必要损耗,实现生产者和消费者之间的双赢对配送中心选址的研究提出了更高的要求。配送中心合理的选址能够产生规模效益,从而提高物流效率,降低物流成本,实现效益的最大化。结合农产品配送中心选址的影响因素和原则,采用重心法模型对福建省的农产品物流配送中心进行选址研究,求出基于总产量和各种农产品的初步位置,然后结合实际情况,对选址地址做进一步的分析,最终确定基于总产量和粮食的最优位置分别位于德化县和大田县。     

物流配送中心选址的多目标优化模型

针对传统选址模型片面追求物流成本最小化而忽视物流服务水平的情况,将可靠性作为物流服务水平的一种测度,提出了配送中心系统可靠度的计算方法,建立了以物流成本最小化和物流服务可靠度最大化为目标的配送中心选址多目标优化模型.采用主要目标法将建立的多目标优化模型转化为单目标优化模型,并运用贪婪取走启发式算法对转化后的模型进行求解.算例结果表明,模型的非劣解充分反映了物流成本与物流服务可靠度之间的悖反关系,同时包含了传统的以物流成本最小化为目标的选址模型的最优解,从而为配送中心选址提供更加全面的决策依据.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-