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1.
基于非关键工序组的资源均衡优化方法   总被引:2,自引:1,他引:2  
对网络计划资源均衡优化中“缩方差法”优化模型进行了分析,针对其调整过程复杂、求解效率低的问题,引入“非关键工序组”的概念,通过对单一工序调整过程的分析,论证了将初始总时差相同的非关键工序视为一个整体进行同步调整的可行性,提出了相应的判别公式、调整原则和方法。该方法减少了大量非关键工序的许多可能开工时间所形成的组合,从而使优化过程的工作量大大减小,使有限时间内的大型工程网络计划的资源均衡优化工作变得可行,使网络计划优化模型进一步完善。  相似文献   

2.
张勇 《科技咨询导报》2007,(8):61-61,63
分支定界法是一种应用范围很广的搜索算法,本文在最优化问题中充分体现了分支定界法的应用,投资问题上充分体现了分支定界法的优越性。  相似文献   

3.
应用工序能力指数(CP值)分析纺织产品工序质量时,往往出现计算的CP值低于1,依此分析判断的工序质量和检测结果不相符合,导致了这一方法在纺织品生产过程中很少应用.针对这一问题提出从产品合格率指标要求出发计算CP值.其结果和实际一致,从而使这一科学方法能够得到推广应用.本文探讨的方法也适用于其他有类似问题的行业.  相似文献   

4.
本文将修正的Dakin分枝定界法用于求解带有线性分式目标的混合整数多目标规划问题,提出了“弹性约束”的概念及其处理方法和交互型分枝定界的两步算法,并将其应用于实际问题中。  相似文献   

5.
讨论了一类两机器流水作业的总延误问题,其中每个工件的操作由“调整”步、“加工”步及“移走”步组成,而工件的调整时间和移走时间均独立于加工时间,同一工件的“调整”步及“移走”步在2台机器上可重叠进行,但“加工”步不能重叠,并且第一台机器上没有空闲时间,工件一旦开始加工就不允许中断.给出了该问题的解中工件排列应满足的条件,并根据这些条件构建了几个近似算法.在构建分支定界算法时,利用问题目标函数的下界及近似算法的结果给出了剪支法则,由此说明所给近似算法对某些例子是很有效的.  相似文献   

6.
冷轧辊生产中机加工环节的关键工序质量控制   总被引:2,自引:0,他引:2  
冷轧辊的加工过程是典型的多工序、多指标的多元质量控制过程,其关键工序的质量尤需严格控制.以某钢铁公司某种冷轧辊产品为例,描述了其加工环节,在对其进行工序分析的基础上,介绍在其机械加工环节中引进关键工序质量控制的必要性,利用改进的田口质量损失函来确定关键工序,并进行多工序过程能力分析及其指数计算,最后通过案例验证了此方法的合理性和有效性.  相似文献   

7.
土地勘测定界是测定土地使用范围,界址地点以及土地的利用现状,作为土地征收、划拔、出让以及开发等土地流转使用的法律依据,是为行政管理部门的审批土地行为而进行的一项技术性服务。随着信息技术的迅猛发展,GPS、RS以及GIS已经逐步运用于我国土地的勘测定界工作之中,因而3s技术已经被土地勘测定界的相关学者所重视,同时其对行政机构处理土地相关问题的意义也十分重大。本文首先对GPS、RS以及GIS技术做出简单介绍,并探讨我国土地勘测定界中如何运用3s技术。  相似文献   

8.
多品种小批量成批成套生产滚动计划的生成方法   总被引:2,自引:0,他引:2  
针对多品种小批量环境下成批成套生产的特点,将加工对象按实际使用率情况分成关键重要零部件和非关键重要零部件两类。根据知识工程的原理,由关键重要零部件的关键工序元知识生成其生产滚动计划;对于非关键重要零部件按照其特性利用"A、B、C分类计划排配法"生成其生产滚动计划。解决了多品种小批量企业产品的成批成套生产问题。  相似文献   

9.
研究了工件带与加工次序有关的安装时间的平行机排序问题,给出它的整数规划模型,并结合动态规划和分支定界方法,给出它的列生成算法.通过试验表明:算法对中等规模的问题是有效的,它可以计算到10台机器和60个工件甚至含有更多大工件的大规模问题.  相似文献   

10.
数学优化模型中分枝定界法的研究   总被引:1,自引:0,他引:1  
一些NP完全问题已有了在实际应用时值得一试的求解算法.本文通过对分枝定界法的进一步分析,采用这种算法,开展数学建模中最优化问题案例的研究.在求解“指派问题”等NP问题上提出分枝定界法的改良思路.  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.
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   

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.
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   

15.
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.  相似文献   

16.
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   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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   

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