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1.
为了保证先来顾客的需求和工件本身错位量的要求,着重研究这种使先来顾客的总目标函数值与工件错位量之间达到平衡的问题,即重新排序问题的Pareto最优解问题.对于最大延迟和工件错位量的Pareto最优解问题,给出了这些问题的多项式时间算法或计算复杂度.  相似文献   

2.
工件加工时间为非线性分段函数的单机排序问题   总被引:1,自引:1,他引:1  
讨论工件加工时间是开工时间非线性分段函数的单机排序问题,目标函数为极小化最大完工时间,总完工时间和加权总完工时间.对于目标函数为极小化最大完工时间和总完工时间的问题,给出了求解最优排序的多项式算法,对于目标函数为加权总完工时间的问题,给出了工件间的一致关系。  相似文献   

3.
加工时间离散可控的分批排序问题   总被引:1,自引:0,他引:1  
分批排序和可控排序是两类重要的现代排序模型,该文中把这两类排序模型相结合,讨论加工时间离散可控的单机分批排序问题:对于所有工件具有相同的可控加工时间和控制费用这一情形,分别考虑机器容量有限及无限两种情况下,分别使最大完工时间和总完工时间加上加工时间可控所需费用的总和为最小作为优化的目标,讨论了这四个问题的最优解的性质,并在此基础上提出了相应的多项式时间最优算法.  相似文献   

4.
讨论了一类工件的加工时间具有学习效应且安装时间带有恶化的成组排序问题,目标函数分别为极小化最大完工时间和极小化总完工时间,1|pij=aij-bijt,S=δit,GT|Cmax,1|pij=aij-bijt,S=δit,GT|∑Cij,并分别给出了求最优解的多项式时间算法,其中极小化总完工时间问题是在bij=b,δi=δ的特殊情况下给出的。  相似文献   

5.
讨论了时间错位和序列错位呈线性关系,即最大时间错位与最大序列错位之和、最大时间错位与总序列错位之和、总时间错位与最大序列错位之和、总时间错位与总序列错位之和限制下,以使总完工时间最小为目标的重新排序问题。重新排序就是原始工件已经按照某种规则使目标函数值达到了最优,但还没有开始加工,这时又有一批新工件到达,要求将新工件与原始工件一起重排使目标函数为最优的排序问题。根据经典排序理论,证明了原始工件与新工件按最短加工时间优先规则可以使目标函数达到最优。由动态规划原理,对每个问题设计并证明了不同的算法及其时间复杂性,最后结合实例作了进一步论证。  相似文献   

6.
讨论带有退化效应的多个交货期窗口的单机排序问题。其目标函数有2种:第1种是带有提前、延误、交货期的开始位置、交货期的大小及最大完工时间的总费用;第2种是带有提前、延误、交货期的开始位置、交货期的大小和所有工件完工时间之和的总费用。目标是找到多个交货期窗口的最优位置、交货期的大小、属于每个交货期窗口的工件集合和工件的最优排序,使目标函数值最小。将该问题转化为指派问题,并证明其多项式时间可解。  相似文献   

7.
本文讨论了加工时间依赖于开工时间的单机排序问题。在这一模型中每个工件具有一个基本加工时间。本文就目标函数为极小化最大完工时间和总完工时间的问题进行了讨论,对某些特殊情况给出了多项式算法。  相似文献   

8.
研究在时间错位限制条件下,继列分批最小化总完工时间的重新排序问题.对于最大时间错位和总时间错位的不同约束情况下,研究可行排序和最优排序的结构性质,进而设计了它们的拟多项式时间算法.  相似文献   

9.
讨论了加工时间依赖于开工时间的单机排序问题.在这一模型中每个工件具有一个基本加工时间,当工件的开工时间超过某个共同的工期后,工件会有一个时间惩罚.本文就目标函数为极小化最大完工时间和总完工时间的问题进行了讨论,对某些特殊情况给出了多项式算法.  相似文献   

10.
针对工件加工时间为非对称模糊数,极小化提前完工惩罚和拖期完工惩罚之和的均值的单机工期指派调度优化问题展开研究.证明了当模糊加工时间具有相同宽度比时,该问题是多项式可解的,并 给出了多项式求解算法.同时根据历史数据,构造了工期指派问题的调度模型,并利用所给出的算法求得最优解,从而 表明所提出的模型和算法的有效性.   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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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