简介:Inflexiblejob-shopbatchschedulingproblem,theoptimallot-sizeofdifferentprocessisnotalwaysthesamebecauseofdifferentprocessingtimeandset-uptime.Evenforthesameprocessofthesameworkpiece,thechoiceofmachinealsoaffectstheoptimallot-size.Inaddition,differentchoicesoflot-sizebetweentheconstrainedprocesseswillimpactthemanufactureefficiency.Consideringthateachprocesshasitsownappropriatelot-size,weputforwardtheconceptofschedulingwithlot-splittingbasedonprocessandsetuptheschedulingmodeloflot-splittingtocriticalpathprocessasthecore.Themodelcouldupdatethesetofbatchprocessandmachineselectionstrategydynamicallytodetermineprocessingrouteandarrangeproperlot-sizefordifferentprocesses,toachievethepurposeofoptimizingthemakespanandreducingtheprocessingbatcheseffectively.Theexperimentresultsshowthat,comparingwithlot-splittingschedulingschemebasedonworkpiece,thismodeloptimizesthemakespanandimprovestheutilizationefficiencyofthemachine.Italsogreatlydecreasesthemachinedbatches(42%)andreducesthecomplexityofshopschedulingproductionmanagement.
简介:Amathematicalmodeltodeterminetheoptimalproductionlotsizeforadeterioratingproductionsystemunderanextendedproductinspectionpolicyisdeveloped.Thelast-Kproductinspectionpolicyisconsideredsothatthenonconformingitemscanbereduced,underwhichthelastKproductsinaproductionlotareinspectedandthenonconformingitemsfromthoseinspectedarereworked.Considerthattheproductsproducedtowardstheendofaproductionlotaremorelikelytobenonconforming,isproposedanextendedproductinspectionpolicyforadeterioratingproductionsystem.Thatis,inaproductionlot,productinspectionsareperformedamongthemiddleK_1itemsandafterinspections,allofthelastK_2productsaredirectlyreworkedwithoutinspections.Ourobjectivehereisthejointoptimizationoftheproductionlotsizeandthecorrespondingextendedinspectionpolicysuchthattheexpectedtotalcostperunittimeisminimized.Sincethereisnoclosedformexpressionforouroptimalpolicy,theexistencefortheoptimalproductioninspectionpolicyandanupperboundfortheoptimallotsizeareobtained.Furthermore,anefficientsolutionprocedureisprovidedtosearchfortheoptimalpolicy.Finally,numericalexamplesaregiventoillustratetheproposedmodelandindicatethattheexpectedtotalcostperunittimeofourproductinspectionmodelislessthanthatofthelast-Kinspectionpolicy.
简介:摘要:目前,我国计量资产采购、验收、检验等关键环节的管理大多仅限于手工或机械式的管理,并未实现全流程的实时监测和闭环管理。本文以NB-IoT技术的特点为切入点,利用NB-IoT技术实现电表配送智能化、闭环化的可行性,为计量资产的全寿命管理提出了新的设想,并对其进行了规范化、标准化设计,为“大营销”系统的正常运作奠定了基础。
简介:摘要随着社会经济的不断发展,水利工程已经成为我国基础建设中的一项重要建设项目,混凝土防渗墙施工作为基础处理工程施工中的重要方式,其施工技术水平的高低直接关系着工程的整体质量。在基础处理工程建设中施工企业必须严格按照每一道工序的规范要求,对各环节质量严格把关,防止各种质量通病的发生,确保整体工程施工质量达到合格水平,并努力实现创优目标。本文主要结合乌干达伊辛巴水电站基础处理工程左岸防渗墙施工的实际情况,从防渗墙平台划分、导墙施工、防渗墙施工方案及施工过程中遇到的问题和质量保证措施进行简要的介绍分析,同时也反映了国外防渗墙工程的施工管理方式和特点。