遗传算法求解物流配送中带时间窗的VRP问题

用遗传算法求解第三方物流企业物流配送中带时间窗的车辆路径问题. 建立了一个配送优化调度模型, 使配送计划的编制在任何情况下都能归约为求解某种车辆路径问题.     

基于非合作博弈的城市食品冷链共同配送定价

城市消费者对保鲜、冷冻食品的需求日益激增,对配送的效率与质量也提出了很高的要求,但当前冷链物流过高的配送成本很大程度上限制了生鲜电商市场的发展.在对城市食品冷链物流发展现状及瓶颈分析的基础上,提出了城市食品冷链2B/2C业务融合共配模式,建立了第三方物流企业与生鲜电商定价博弈模型,得出通过定价折扣策略可以提高博弈双方的收益的结论.可以为第三方物流与生鲜电商开展冷链B2C配送业务提供参考.     

考虑客户满意度的带时间窗的多中心半开放式冷链物流车辆路径优化

针对带时间窗的多中心半开放式车辆路径问题，以总配送成本最小化和客户满意度最大化为目标，提出了双目标冷链物流路径优化模型。针对NSGA-Ⅱ算法容易陷入局部最优等缺点，结合粒子群算法生成种群方式，设计一种改进的NSGA-Ⅱ算法。通过仿真对比实验，结果表明，所提出的算法和模型可有效解决带时间窗的多中心半开放式冷链物流车辆路径优化问题，且改进算法性能更优，同时分析了总配送成本与客户满意度之间的关系，为冷链物流企业带来一定的管理启示。     

时变路网环境下多温冷链配送路径优化研究

【目的】生鲜产品在冷链物流配送过程中的新鲜度及货损成本与配送行程所耗时间密切相关,而配送车辆在城市路网中不同时段行驶的速度不同,基于此在考虑了道路交通状况的时变路网特性之后研究配送的优化问题。【方法】针对时变路网环境下的多温区产品配送车辆调度问题,考虑载重质量与车厢容积及时间窗约束,建立由运输成本、货损成本及制冷成本构成的目标为总配送成本最小的数学优化模型,设计基于模拟退火算法的求解程序,并用MATLAB对实例进行求解。【结果】与以往研究中用平均速度方法求解出时间变量的方法不同,通过时变路网理论及模型求解,验证了时变路网环境下冷链配送路径优化模型及算法的有效性。【结论】结合时变路网,改进了货损成本中腐败函数的时间变量求解方法,刻画了各配送车辆每完成一个客户的配送后,车辆剩余货物在余下配送时间里货损成本继续发生的动态过程。     

基于离散蜂群的应急物流车辆调度算法

为在尽可能满足应急物流时间要求的前提下最大程度的节约运输成本,提出了一种基于离散蜂群的应急物流车辆调度算法.该算法首先综合考虑运输车装载容量和受灾点的单边硬时间窗约束,构建了以最小化配送成本为目标的数学规划模型,然后利用离散蜂群算法进行优化求解,通过引入离散差分搜索强化其领域搜索能力,同时借助侦查蜂进行个体淘汰操作,从而避免算法陷入局部最优.仿真实验表明,与基于蚁群算法的应急物流车辆调度算法相比,该算法具有较强的鲁棒性,能够快速获得应急物流车辆调度问题的优质解.     

区域配送中心物流调度模型

针对物流系统调度中存在的区域配送"少批量,多批次"供货要求的问题,作者用时间片规范订单,通过拆分、组合订单及优化调度计划,降低成本.以某企业工程实践为背景,提出了一类区域配送的物流调度模型.该物流调度模型运用组合优化的思想,基于中央配送中心、区域配送中心、门店形成的三级运输配送体系结构,提出了在一定的约束条件(时间约束条件和空间约束条件)下,以最小成本实现物流调度计划的方法.求解算例表明,该模型对解决多货品、多门店的供货问题是有效的.     

基于双模式更新五行环算法的多目标冷链配送

针对生产运输中广泛存在的冷链配送问题，建立了以配送成本最小化和顾客满意度最大化为目标函数的多目标冷链物流优化模型。基于五行环优化(FECO)算法，提出了双模式更新个体的五行环优化算法(FECO-DMUI)，并对多目标冷链物流模型进行求解。将FECODMUI算法与FECO算法、NSGA-II算法、鲸鱼优化算法和灰狼优化算法进行比较，结果验证了本文模型和算法的有效性，同时验证了FECO-DMUI算法在多目标冷链配送问题中能更加高效地获得路径优化的最优解集。     

考虑动态需求的多中心沿途补货冷链物流配送路径优化

为提升冷链物流配送效率、降低物流成本,本文在综合考虑多配送中心、客户动态需求、沿途补货策略的前提下,建立以总配送成本和客户满意度最优为目标的冷链物流配送模型.模型采用主目标法处理客户满意度和成本之间的背反关系,将动态问题按照时间轴依次分解为一系列的静态调度子问题并考虑了5种配送成本.本文提出自适应大邻域搜索算法求解该模型,设计了三种破坏算子和三种修复算子,对小中大三种不同规模的算例进行测算.结果表明该算法在速度、精度和稳定性上表现良好,对求解此类问题有较好的适应性和准确性.与不考虑沿途补货策略的动态配送方案相比,沿途补货策略可使成本降低23.06%、客户满意度提升8.69%.结果表明提出的配送方案可很好地节约企业的配送资源、减少配送成本、增强竞争力.     

改进遗传算法求解带模糊时间窗冷链配送问题

为优化冷链物流配送路径,降低配送成本、提高客户对产品送达时间的满意度水平是冷链物流的关键。考虑到冷链物流承载的货物具有一定的特殊性且对温度的要求较高,提出在冷链物流配送中设定模糊时间窗反映顾客满意度。建立了运输成本、货损成本、时间成本等配送成本最小化和以模糊时间窗进行量化客户满意度最大化的多目标优化模型,采用改进遗传算法求解带模糊时间窗冷链配送问题。通过算例分析,验证了模型和算法的有效性与研究的实用价值。     

集散区域快递物流车辆调度模型及其算法

在分析集散区域快递物流运输特点的基础上,研究了固定时间窗内多车型车辆往返运输的车辆调度问题,建立以运输总成本最小为目标的数学模型,并给出遗传算法求解办法。实例表明,该模型和算法能有效地满足物流车辆调度需求,降低企业的物流成本。     

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.     

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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