简介:TheconstructionoftheGeologicTimeScale(GTS)isatitanicscientificchallengethathasbeenunderwayfortwocenturiesandwillrequiremuchdedicatedeffortinthefuture.ItalypreservesaparamountstratigraphicrecordofMesozoicandCenozoicmarinesedimentsthathavebeensignificantinthedevelopmentofthemodernGTS.TheItalianstratigraphicrecordhasbeenhistori-callyimportantinintroducinganddefiningthestandardChronostratigraphicUnits(CUs)oftheNeogeneandQuaternary.PelagicsuccessionsfromNorthernApen-ninesandSouthernAlpshavebeenusedintheseventiesforintegratingthelateCretaceous-PaleogeneGeomag-neticPolarityTimeScale(GPTS)withplanktonicmicrofossilbiostratieraohvandstandardCUs.Thiswasamajorcontributiontotheconstructionofanewgener-ationofGTSbasedonintegratedmagnetobiochronol-ogy.ThemiddleMiocenetoearlyPleistocenemarinerecordfromSicilyandsouthernItalyhasbeenfunda-mentalforestablishingtherecentlydevelopedAstro-nomicalTimeScale(ATS).Inprospect,therearemanypotentialsstilltobeexploitedintheItalianmarinestratigraphicrecordforimplementingtheGTSbydefin-ingGSSPsofvariousCUs,improvingmagneto-biochronologyandextendingdownwardstheATS.
简介:Twolargeexplosiontrials(5000kgTNTand500kgANFO)wereconductedinWoomera,AustraliainApril/May2006.AdvanceProtectiveTechnologiesforEngineeringStructures(APTES)grouptested2largesingle-storeyconcretemoduleswithindividualcomponentssuchasdoors,windowsandtiledpanels.Adescriptionofthetrialanddetailsofvariousmodulestestedinthesetrialsarepresentedinthepaper.Numericalmodellingandsimulationsareperformedusingcomputerprograms,CONWEP,AIR3DandAUTODYN.Acomparisonofthepressuretimehistoriesobtainedusingthesecodesismadealongwiththeconcludingremarks.
简介:Multi-cellmulti-usermultiple-inputmultiple-output(MC-MU-MIMO)isapromisingtechniquetoeliminateinter-userinterferenceandinter-cellcochannelinterferenceinwirelesstelecommunicationsystems.AsthelargenumberofusersinthesystemandthelimitednumberofsimultaneouslysupportableuserswithMC-MU-MIMO,itisnecessarytoselectasubsetofuserstomaximizethetotalthroughput.However,thefullycentralizeduserselectionalgorithmsusedinsinglecellsystem,whichwillincurhighcomplexityandbackhaulloadinmulti-cellcooperativeprocessing(MCP)systems,arenotsuitabletoMC-MU-MIMOsystems.ThisarticlepresentsatwocascadeduserselectionmethodforMCPsystemswithmulti-cellblockdiagonalization.Inthispaper,alocaloptimalsubsetofusers,whichcanmaximizethelocalsumcapacity,isfirstchosenbythegreedymethodineverycooperativebasestationinparallel.Then,allthecooperativebasestationsreporttheirlocaloptimaluserstothecentralunit(CU).Finally,theglobaloptimalusers,whichcanmaximizetheglobalsumcapacityofMCPsystems,areselectedfromtheaggregatedlocaloptimalusersattheCU.Thesimulationresultsshowthattheproposedmethodperformscloselytotheoptimalandcentralizedalgorithm.Meanwhile,thecomplexityandbackhaulloadarereduceddramatically.
简介:Aschemeisproposedtoelevatethelimitationofthegroundapplicationsystemofmono-satellite-sensorundertherequirementofremotesensingsatellitegroundapplicationsystem.Intheresource-sharing,forinstancecaculatingresource,asimplephototypeofcaculating-resourceisproposedthroughanalyzingresourceassignment,applicationassignment,bodystructure,andsoon.Inordertoimprovetheabilityofassignment,realizethefavorableutility,management,andmaintenance,thephototypeisimprovedbyusingdatagridcalculationaccordingtotherequirementandcharacterofactualapplication.Thephototypecanbetakenasthefoundationofcalculationframeofremotesensinggroundapplicationsystemofmulti-satelliteandmulti-sensor.
简介:In2005,Bao,etal.[Appl.Math.andComput.,vol.169,No.2,2005]showedthatTzeng,etal.’snonrepudiablethresholdmulti-proxymulti-signatureschemewithsharedverificationwasinsecure,andproposedanimprovedschemewithnoShareDistributionCenter(SDC).ThispapershowsthatBao,etal.’sschemesuffersfromtheproxyrelationshipinversionattackandforgeryattack,andpro-posesanimprovementofBao,etal.’sscheme.
简介:Toenhancetheexpressivepowerandthedeclarativeabilityofadeductivedatabase,variousCWA(ClosedWorldAssumption)formalizationsincludingthenaiveCWA,thegeneralizedCWAandthecarefulCWAareextendedtomulti-valuedlogics.Thebasicideaistoembedlogicformulasintosomepolynomialring.Theextensionscanbeappliedinauniformmannertoanyfinitelymulti-valuedlogics.Thereforetheyarealsoofcomputationalsignificance.
简介:Anewall-opticaldemultiplexerbasedonnonlineareffectinsemiconductorlaseramplifier(SLA)isproposed.ItcandemultiplexallchannelsoftheOTDMsignalconcurrently.anditcanalsobeintegratedonasinglechip.TheproposeddeviceconsistsofaseriesshortFabry-Perotamplifiers(FPSLA)settingonthepathverticsally,throughwhichthepreamplifiedopticalsignaltravels.Perpendicularlytothesignal,K(channelnumber)paralleledbeamsoflightpulse,whichactasprobeswithrepetitionatthebitrateofonechannel,irradiateontheseFP-SLAs,respectively,justwhenthecorrespondingsignalchannelpulsepassesthroughtheactiveregionfromlateralside.Thetransmissivitydependsonthesignalpulse.Theoreticalanalysishasbeengiven.Asademonstratingexample,Adeviceoperatedatthespeedof25Gbit/s(2.5Gbit/s×10)issimulatedandtheresultsshowthattheabout9.24dBextinctionratiocanbeachievedeasily.
简介:Wepresentthesolidmodeleditdistance(SMED),apowerfulandflexibleparadigmforexploitingshapesimilaritiesamongstCADmodels.ItisdesignedtomeasurethemagnitudeofdistortionsbetweentwoCADmodelsinboundaryrepresentation(B-rep).Wegivetheformaldefinitionbyanalogywithgrapheditdistance,oneofthemostpopulargraphmatchingmethods.Toavoidtheexpensivecomputationalcostpotentiallycausedbyexactcomputation,anapproximateprocedurebasedonthealignmentoflocalstructuresetsisprovidedinaddition.Inordertoverifytheflexibility,wemakeintensiveinvestigationsonthreetypicalapplicationsinmanufacturingindustry,anddescribehowourmethodcanbeadaptedtomeetthevariousrequirements.Furthermore,amultilevelmethodisproposedtomakefurtherimprovementsofthepresentedalgorithmonbotheffectivenessandefficiency,inwhichthemodelsarehierarchicallysegmentedintotheconfigurationsoffeatures.ExperimentresultsshowthatSMEDservesasareasonablemeasurementofshapesimilarityforCADmodels,andtheproposedapproachprovidesremarkableperformanceonareal-worldCADmodeldatabase.
简介:Duetothefeaturesofthemulti-spectralimages,theresultwiththeusualmethodsbasedonthesupportvectormachine(SVM)andbinarytreeisnotsatisfactory.Inthispaper,afuzzySVMmulti-classclassifierwiththebinarytreeisproposedfortheclassificationofmulti-spectralimages.Theexperimentisconductedonamulti-spectralimagewith6bandswhichcontainsthreeclassesofterrains.Theexperimentalresultsshowthatthismethodcanimprovethesegmentationaccuracy.
简介:Amodelhelicopterismoredifficulttocontrolthanitsfullscalecounterpart.Thisisduetoitsgreatersensitivitytocontrolinputsanddisturbancesaswellashigherbandwidthofdynamics.Thisworkisfocusedondesigningpracticaltrackingcontrollerforasmallscalehelicopterfollowingpredefinedtrajectories.Atrackingcontrollerbasedonoptimalcontroltheoryissynthe-sizedasapartofthedevelopmentofanautonomoushelicopter.Someissueswithregardstocontrolconstraintsareaddressed.Theweightingbetweenstatetrackingperformanceandcontrolpowerexpenditureisanalyzed.Overallperformanceofthecontroldesignisevaluatedbasedonitstimedomainhistoriesoftrajectoriesaswellascontrolinputs.
简介:我们考虑在位于没有规模的网络的联合振荡器的synchronizability上聚类系数的效果。聚类系数瞄准一个高度聚类的没有规模的网络模型,的价值的分析结果Holme-Kim模型被获得,并且在网络synchronizability之间的关系和聚类的系数被报导。Thesimulation结果强烈建议那越多聚类网络,越poorerthesynchronizability。
简介:Large-scaleMIMO(multiple-inputmultiple-output)systemswithnumerouslow-powerantennascanprovidebetterperformanceintermsofspectrumefficiency,powersavingandlinkreliabilitythanconventionalMIMO.Forlarge-scaleMIMO,thereareseveraltechnicalissuesthatneedtobepracticallyaddressed(e.g.,pilotpatterndesignandlow-powertransmissiondesign)andtheoreticallyaddressed(e.g.,capacitybound,channelestimation,andpowerallocationstrategies).Inthispaper,weanalyzethesumrateupperboundoflarge-scaleMIMO,investigateitskeytechnologiesincludingchannelestimation,downlinkprecoding,anduplinkdetection.Wealsopresentsomeperspectivesconcerningnewchannelmodelingapproaches,advanceduserschedulingalgorithms,etc.
简介:尽管有在中国喷雾器上增加注意,从来没有它的一般特征的遍及全国的调查。这份报纸在23个地点为喷雾器论述元素的数据在并且在中国附近,主要从文学,和表演绘画一些大规模模式。艾尔,Na,和Se被用来代表外壳,水兵,和污染部件分别地。大多数模式在SWNE被排列。分别地,艾尔和Na对NW和SE最高级,他们的比率变化很快接近海岸。Se从NW日益增多地在华中,和Se/Al比率(污染对外壳的喷雾器的指示物)增加上有宽广最大值到SE。为模仿污染喷雾器的一个简单索引,使用人口密度,年度降水,和吝啬的风速度,足够地复制污染喷雾器的大规模模式并且显示出在NW的外壳的艾尔怎么逐渐地向SE让路给flyash艾尔。
简介:Landbreezeisatypeofmesoscalecirculationdevelopedduetothermalforcingoveraheterogeneouslandscape.Itcancontributetoatmosphericdynamicandhydrologicprocessesthroughaffectingheatandwaterfluxesontheland-atmosphereinterfaceandgeneratingshallowconvectiveprecipitation.Ifthescaleofthelandscapeheterogeneityissmallerthanacertainsize,however,theresultinglandbreezebecomesweakandbecomesmixedupwithotherthermalconvectionslikethermals.Thisstudyseekstoidentifyascalethresholdtodistinguishtheeffectsbetweenlandbreezeandthermals.Two-dimensionalsimulationswereperformedwiththeRegionalAtmosphericModelingSystem(RAMS)tosimulatethermalsandlandbreeze.Theirhorizontalscalefeatureswereanalyzedusingthewavelettransform.Thethermalsdevelopedoverahomogeneouslandscapeunderdryorwetconditionshaveaninitialscaleof2-5kmduringtheirearlystageofdevelopment.Thescalejumpsto10-15kmwhencondensationoccurs.Thesolutionofananalyticalmodelindicatesthatthereduceddegreeofatmosphericinstabilityduetothereleaseofcondensationpotentialheatcouldbeoneofthecontributingfactorsfortheincreaseinscale.Thelandbreeze,ontheotherhand,hasamajorscaleidenticaltothesizeofthelandscapeheterogeneitythroughoutvariousstagesofdevelopment.Theresultssuggestthattheeffectsoflandbreezecanbeclearlydistinguishedfromthoseofthermalsonlyifthesizeofthelandscapeheterogeneityislargerthanthescalethresholdofabout5kmfordryatmosphericprocessesorabout15kmformoistones.