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1.
考虑客户服务水平,以运输成本、越库中心作业和固定成本、延迟交货惩罚成本总和最小化为目标,建立越库中心选址的混合整数规划模型.在中小规模情形下,运用lingo求问题的精确解,同时根据模型中目标函数的不同特征,构建2种启发式算法求问题的近优解.实验结果表明:在所测的20组数据中,性能较优的启发式算法H2求得的解与精确解的平均误差分别为0.28%和3.24%,接近于精确解,这表明启发式算法H2是有效的.  相似文献   

2.
在对文题进行数学描述的基础上,建立求解该类问题的混合整数线性规划模型.证明问题NP 困难性并研究多项式可解子问题,进一步提出了3个启发式算法以及精确求解的分支定界算法.数值实验表明,所提出启发式算法以及分支定界算法的有效性与高效性.  相似文献   

3.
【目的】给出具有截断学习效应的加权总完工时间流水作业排序问题的最优解。【方法】建立具有截断学习效应的加权总完工时间流水作业排序问题的数学模型,给出优势性质、下界和上界,并采用分支定界算法求解该问题的最优解。【结果】数值模拟结果表明:启发式算法得到的解比较准确,最大误差为 0.4117 ,分支定界算法的效率比较高,处理 100 个工件所用的最大时间不超过 460s 。【结论】计算结果表明分支定界算法能够很快地给出该问题的最优排序。
  相似文献   

4.
一类混合整数双层线性规划的枚举法   总被引:1,自引:1,他引:0  
通过对上层变量为0-1型变量和下层变量为连续型变量的混合整数双层线性规划问题的,根据分支定界法原理,给出了一种定界函数和寻找问题最优解的搜索准则,由此提出了一个求解混合整数双层线性规划问题的有效枚举方法。提出的算法能求得问题的全局最优解,并通过算例说明了算法的求解过程。  相似文献   

5.
针对汽车入厂物流中的订单协同问题,建立了混合整数规划模型,提出了启发式算法和分支定界法,并采用数值实验验证了模型和算法的可行性.结果表明:启发式算法和分支定界法的计算速度和结果均优于CPLEX求解数学模型;协同订单量可有效降低总成本.  相似文献   

6.
研究运输时间不确定环境下基于循环取料的越库调度问题.对问题建立不确定情况下求解该问题的混合整数规划模型;提出2阶段启发式算法和基于禁忌搜索算法的改进算法来获得近似最优解;通过在小规模和大规模情形下进行数值实验,验证了启发式算法的有效性.  相似文献   

7.
以最小化客户的最晚交货时间为目标,建立了多车辆直运越库物流调度问题的混合整数线性规划模型,并使用优化工具ILOG CPLEX求解得到了适当规模问题和小规模问题的精确最优解;基于最大加工时间(LPT)规则,提出求解多车辆直运越库物流调度问题的启发式算法,通过对中等以及大规模实例的数值计算,比较了混合整数线性规划模型和启发式算法之间的计算性能.结果表明,启发式算法具有良好的近似性能,所测24组实例中的相对误差不超过9.5%,接近于精确解.  相似文献   

8.
【目的】给出具有截断学习效应的加权总完工时间流水作业排序问题的最优解。【方法】建立具有截断学习效应的加权总完工时间流水作业排序问题的数学模型,给出优势性质、下界和上界,并采用分支定界算法求解该问题的最优解。【结果】数值模拟结果表明:启发式算法得到的解比较准确,最大误差为0.411 7,分支定界算法的效率比较高,处理100个工件所用的最大时间不超过460s。【结论】计算结果表明分支定界算法能够很快地给出该问题的最优排序。  相似文献   

9.
目标函数为加权完成时间和的单机维护调度问题研究   总被引:1,自引:0,他引:1  
讨论了带有可控性维护的单机调度问题,目标是实现工件加权完成时间和的最小化.此问题是强 NP难的,因此给出了三个启发式算法和一个分枝定界算法,并通过实验对这些算法进行评价.实验结果表明其中的两个启发式算法(WSPT算法和综合算法)能得到比较好的近似最优解,分枝定界算法对小规模(n≤10)的问题很容易得到最优解.  相似文献   

10.
蚁群算法求解独立到达时间单机提前/拖期调度问题   总被引:3,自引:0,他引:3  
求解有独立到达时间和完工时间的单机调度问题目前主要采用启发式算法。为研究仿生类算法的应用可行性,采用蚁群算法,以提前/拖期的总惩罚量达到最小为目标。将邻位工作交换法(AP I)用于局部搜索以提高解的质量,并对每一个解的相邻工作间隔时间进行优化调整。用90个测试算例,将蚁群算法求解结果与分支定界法和禁忌搜索法的结果进行比较。结果表明,蚁群算法与分支定界法和禁忌搜索法的结果相当。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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-  相似文献   

16.
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-  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<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  相似文献   

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