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1.
针对石油钻井物料成本高、损耗模糊不确定、管理控制难的现状,采用企业资源计划物料清单的概念构建了石油钻井物料清单,并运用模糊数学和期望值方法建立了损耗数量为模糊数的石油钻井物料清单的模糊数量模型,给出了模型相应的求解过程.该模型的建立对模糊环境下石油钻井企业优化采购、降低库存成本、有效实施企业资源计划系统有一定的意义.  相似文献   

2.
寻求最佳质量成本点是企业质量成本控制的目标,质量管理贯穿于整个生产活动过程中,通过对质量管理活动的流程以及质量管理和BOM(物料清单)、BOP(工艺清单)的关系的分析,设计了质量-成本指标体系和基于质量-成本优化的质量管理模型.  相似文献   

3.
区块链可以广泛用于商品的溯源与实物信息的可信记录。目前的区块链系统能够支持的物品逻辑关系比较简单,通常只对某一个单品做追溯。如果在流通的过程中,需要将商品组合成批次,批次的信息只能通过中心化的数据库记录。本文提出了一种基于混合树的区块链层级化溯源的设计与实现。根据多个溯源单品或批次的基本数据,构建树状结构;当一个或多个溯源单品或批次组合成一个新的批次时,对组合后的批次信息构建标识ID以及与原有树状结构的关联信息,将批次信息与其他商品节点信息构建一个新的Merkel树,并将所述新的树状结构的根哈希记录到区块链。这样,通过区块链同时记录单品与批次的溯源信息,实现对层级隶属关系的去中心化确认和追溯,从而能够同时对某个单品和隶属的批次进行灵活全方面的信息追溯。  相似文献   

4.
基于不确定条件的再制造物流网络优化设计   总被引:1,自引:0,他引:1  
针对废旧产品到达时间和数量、废旧产品回收与再制造产品需求平衡、废旧产品可利用率等不确定性特点,综合考虑多产品、多周期、容量限制等影响因素,将废旧产品回收数量、再制造产品需求数量、废旧产品利用率作为随机参数,以物流网络构建的总成本最小化为目标函数,建立了不确定条件下的随机机会约束规划模型,用以确定物流网络结点设施的位置、数量和物流量.设计了融合随机模拟和线性规划的混合遗传算法对模型进行直接求解,有效提高了算法的局部寻优能力.算例分析表明,基于不确定条件的随机机会约束规划模型比确定条件下模型考虑了更多的实际因素,因此能够更好地满足再制造企业物流战略决策的需要.  相似文献   

5.
针对零件再制造过程能耗评估困难问题,建立基于图形评审技术(graphical evaluation and review technology,GERT)的能耗模型.首先,分析了零件再制造过程中能耗特性及能耗不确定性的原因,阐述再制造过程各工序能量消耗的一般规律.其次,基于GERT建立了零件再制造过程能耗模型,给出了不同再制造处理方式的概率和期望能耗的计算方法.最终以发动机曲轴的再制造过程为案例对所提出的模型和方法进行了验证,并与Arena软件仿真结果进行了对比分析,验证了结果的合理性.  相似文献   

6.
随着环境和资源问题的日益突出,再制造作为低熵化发展模式受到越来越多的重视。我们在详细分析工艺路线选择对再制造加工质量及生态环境影响的基础上,以质量、生态环境及物料搬运为目标建立再制造系统制造单元构建模型,并提出遗传算法求解模型,再通过算例的详细分析来说明环境、质量及物料搬运目标对构建方案的影响。  相似文献   

7.
以网络爬虫方式获取新浪微博用户属性信息及微博内容数据,利用数据挖掘技术从中发现微博用户间的多种显式和隐式关系.在此基础上,提出一种基于半监督学习的用户兴趣匹配预测算法,参照仓室模型的传播个体状态划分方法,基于传播个体间的兴趣匹配度界定各状态之间的转移过程和转移概率,进而构建基于用户兴趣匹配的网络舆情传播模型.研究结果表明,该模型能够较好地描述社交网络中的舆情传播规律,重现网络舆情在社交网络中的真实传播过程链.  相似文献   

8.
在制造/再制造物流网络的不同周期,新产品和再制造品的销售市场可能不同.针对此情形,考虑市场主体对新产品和再制造品需求量的不确定性,以构建物流网络总成本最小为目标,建立制造/再制造物流网络的多周期动态选址模型.通过算例求解,确定各周期物流网络中设施的数量、位置及设施间的物流量分配并验证模型的有效性.  相似文献   

9.
在前期基于图网络的模型基础上,引入角色指代信息,提出融合角色指代的多方对话关系抽取模型.在构建图节点时加入角色节点,将其与对应角色指代的词节点进行连接,并使用图注意力网络进行编码.在DialogRE数据集上的实验效果与基线模型相比,F1值在验证集上提升2.9%,在测试集上提升4.6%.  相似文献   

10.
针对工业互联网产品信息追溯问题,提出一种基于区块链的工业互联网产品追溯系统.首先引入可拓学原理中的转换桥方法解决低层区块链数据采集的表示异构问题;其次采用改进的拜占庭算法建立共识,以此保证区块链节点的一致性;最后以C语言和以太坊geth区块链作为基础,对该区块链追溯系统进行开发,并给出部分信息追溯展示和区块链数据防伪验...  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.
<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   

19.
20.
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has  相似文献   

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