简介:Thispaperpresentsanapplicationofgain-scheduling(GS)controltechniquestoafloatingoffshorewindturbineonabargeplatformforaboveratedwindspeedcases.Specialemphasisisplacedonthedynamicsvariationofthewindturbinesystemcausedbyplantnonlinearitywithrespecttowindspeed.Theturbinesystemwiththedynamicsvariationisrepresentedbyalinearparameter-varying(LPV)model,whichisderivedbyinterpolatinglinearizedmodelsatvariousoperatingwindspeeds.Toachievecontrolobjectivesofregulatingpowercaptureandminimizingplatformmotions,bothlinearquadraticregulator(LQR)GSandLPVGScontrollerdesigntechniquesareexplored.ThedesignedcontrollersareevaluatedinsimulationswiththeNREL5MWwindturbinemodel,andcomparedwiththebaselineproportional-integral(PI)GScontrollerandnon-GScontrollers.ThesimulationresultsdemonstratetheperformancesuperiorityofLQRGSandLPVGScontrollers,aswellastheperformancetrade-offbetweenpowerregulationandplatformmovementreduction.
简介:Theeffectsofgaincompressiononthemodulationdynamicsofanopticallyinjectedgainleversemiconductorlaserarestudied.Calculationsrevealthatthegaincompressionisnotnecessarilyadrawbackaffectingthelaserdynamics.Withapracticalinjectionstrength,ahighgainlevereffectandamoderatecompressionvalueallowustotheoreticallypredictamodulationbandwidthfourtimeshigherthanthefree-runningonewithoutagainlever,whichisofparamountimportanceforthedevelopmentofdirectlymodulatedbroadbandopticalsourcescompatiblewithshort-reachcommunicationlinks.
简介:Lowgainfeedbackreferstocertainfamiliesofstabilizingstatefeedbackgainsthatareparameterizedinascalarandgotozeroasthescalardecreasestozero.Lowgainfeedbackwasinitiallyproposedtoachievesemi-globalstabilizationoflinearsystemssubjecttoinputsaturation.Itwasthencombinedwithhighgainfeedbackindifferentwaysforsolvingvariouscontrolproblems.Theresultingfeedbacklawsarereferredtoaslow-and-highgainfeedback.Sincetheintroductionoflowgainfeedbackinthecontextofsemi-globalstabilizationoflinearsystemssubjecttoinputsaturation,therehasbeenefforttodevelopalternativemethodsforlowgaindesign,tocharacterizekeyfeaturesoflowgainfeedback,andtoexplorenewapplicationsofthelowgainandlow-and-highgainfeedback.Thispaperreviewsthedevelopmentsinlowgainandlow-and-highgainfeedbackdesigns.
简介:安排在许多不同服务工业起一个重要作用。在这份报纸,我们提供一些出现在各种各样的服务工业的更重要的安排问题的概述。我们集中于如此的问题的明确的表达以及在使用解决那些问题的技术上。我们考虑在服务工业安排的五个区域,也就是(i)projectscheduling,(ii)安排的员工,(iii)timetabling,保留,和约会,(iv)安排的交通,并且(v)在娱乐安排。开始的二个区域是相当一般的并且在许多不同服务工业有应用。第三,第四和第五个区域是与一些很特定的服务工业有关的更多,也就是好客和护理工业,交通工业(旅客以及货物),并且娱乐工业。在我们的结论节,我们讨论在各种各样的不同工业使用的问题明确的表达和答案技术的类似和差别,我们也讨论为在服务工业安排被开发了的决定支持系统的设计。
简介:Thispaperstudiestherelationshipbetweentwoprincipaltoolsfortheanalysisofnetworktraffic,namely,effectivebandwidthandnetworkcalculus.Itisshownthatageneralformulationofeffectivebandwidthcanbeexpressedwithintheframeworkofaprobabilisticversionofthenetworkcalculus,wherebotharrivalsandservicearespecifiedintermsofprobabilisticbounds.Aggregateschedulingwithstatisticalserviceassurancesbasedonstatisticalnetworkcalculusispresentedbystrongeffectiveenvelopefunction,insteadofcommonlyusedeffectiveenvelopetoobtainboundsontheamountoftrafficonalink,theproposedschemecanovercometheoverestimationofthenumberofadmittedflows,whichmakesitsuperiortothepreviousschemeespeciallywhenimplementingcalladmissioncontrol.
简介:Intheviewofstaffshortagesandthehugeinventoryofproductsinthecurrentmarket,weputforwardapersonnelschedulingmodelinthetargetofclosingtothedeliverydateconsideringtheparallelism.Thenwedesignedaschedulingalgorithmbasedongeneticalgorithmandproposedaflexibleparalleldecodingmethodwhichtakefulluseofthepersonalcapacity.Casestudyresultsindicatethattheflexiblepersonnelschedulingconsideringtheorder-shopscheduling,machineautomaticcapabilitiesandpersonnelflexibleinthetargetofclosingtothedeliverydateoptimizetheallocationofhumanresources,thenmaximizetheefficiency.
简介:AbstractBackground:Gestational weight gain (GWG) is associated with the risk of gestational diabetes mellitus (GDM). However, the effect of weight gain in different trimesters on the risk of GDM is unclear. This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen, China. In total, 51,205 participants were included comprising two models (early pregnancy model and middle pregnancy model). Gestational weight (kg) was measured at each prenatal clinical visit using a standardized weight scale. Logistic regression analysis was used to assess the risk of GDM. Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model, the risk of GDM was 0.858 times lower (95% confidence interval [CI]: 0.786, 0.937) with insufficient GWG (iGWG) and 1.201 times higher (95% CI: 1.097, 1.316) with excessive GWG after adjustment. In the middle pregnancy model, the risk of GDM associated with iGWG increased 1.595 times (95% CI: 1.418, 1.794) after adjustment; for excessive GWG, no significant difference was found (P = 0.223). Interaction analysis showed no interaction between GWG in early pregnancy (GWG-E) and GWG in middle pregnancy (GWG-M) (F = 1.268; P = 0.280). The mediation effect analysis indicated that GWG-M plays a partial mediating role, with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM. Strict control of weight gain in early pregnancy is needed, and sufficient nutrition should be provided in middle pregnancy.
简介:Motivatedbytheprojectsconstrainedbyspacecapacityandresourcetransportingtime,aprojectschedulingproblemwithcapacityconstraintwasmodeled.Ahybridalgorithmisproposed,whichusestheideasofbi-levelschedulingandprojectdecompositiontechnology,andthegeneticalgorithmandtabusearchiscombined.Topologicalreorderingtechnologyisusedtoimprovetheeffciencyofevaluation.Simulationresultsshowtheproposedalgorithmcanobtainsatisfiedschedulingresultsinacceptabletime.
简介:SinceManufacturingExecutionSystem(MES)isabridgewhichlinkstheupperplanningsystemoftheenterpriseandthecontrolsystemoftheshopfloor,variouskindsoftheinformationwithdifferentcharacteristicsflowthroughthesystem.TheinformationenvironmentofMESanditseffectonMESschedulingareanalyzed.Amethodologicalproposalisgiventoaddresstheproblemofagileschedulinginacomplexinformationenvironment,basedonwhichamicroeconomicmarketandgametheoreticmodel-basedschedulingapproachispresented.Thefuturedevelopmentofthismethodisalsodiscussed.
简介:Deadlockmustbeavoidedinamanufacturingsystem.Inthispaper,anefficientalgorithmforfindinganoptimaldeadlock-freeschedulesinamanufacturingsystemwithverylimitedbufferispresented.Thisalgorithmisbasedonheeffectivegeneticalgorithm(GA)searchmethod,andaformalPetrinetstructureisintroducedtodetectthetokenplayerassuringdeadlock-free.InordertomaketheschedulingstrategygeneratedbyGAmeettherequiredconstraintofdeadlock-free,someresultsofthestruetureanalysisofPetrinetareinvolvedasacriteriontoselectdeadlock-freeschedulefromthepopulationgeneratedbyGA.Theeffectivenessandefficiencyoftheproposedapproachisillustratedbyusinganexample.
简介:Aplasmoniccavityfilledwithactivematerialisproposedtoexplainopticalswitching.Opticalproperties,includingtransmission,responsetime,andfielddistributionofon/offstate,arenumericallyinvestigated.Wedemonstratethatsuchagain-assistedplasmonicstructurecanachieveopticalswitchinginthenan-odomainandshortentheswitchingtimetothesubpicosecondlevel.Ourresultsindicatethepotentialapplicationoftheproposedstructureinopticalcommunicationandphotonicintegratedcircuits.