简介:Ageonetricalmoirémethodfordisplayingdirectlyisochromaticsandisoclinicsofadiametricallypressedcirculardiskispresented.ItisdemonstratedthatbyusingtwoidenticalordifferentWulffnets(orgrids)notonlythestressfieldsofacirculardiskcanbedisplayed,buttheu-andv-displacementfieldscanalsobeproduced.
简介:Anewauditorysystemmodelbasedonacombinationofphysiologicalandpsycho-logicalacousticdatahasbeenproposed.Thismodelconsistsofabankofnonuniformbandpassfilters,detectorsandmain-frequencychoosingmechanisms,theyactasbasilarmembranes,innerhaircellsandnervefibers,respectively.Combiningwiththeimprovedcriticalbandwidthpa-rameters,theinputtothismodelisanalogoustothepressureattheeardrum,andtheoutputofthismodelsimulatesvariousfeaturesofthefiringpattern.Thesynthesizerobtainstheresul-tantspeechbyuseofthesimpleaddingmethod.Computersimulationsshowthattheresultantspeechishighlyintelligibleandnatural.Theproposedmodeliscorrectandtheimprovementofthecriticalbandwidthparametersiseffective.
简介:Inbandpasssigmadeltamodulator,resonatoristhekeyblock.Thispaperproposedanewresonatorwhichcansimplifythecircuitimplementationwhendesigningbandpassmodulatorwithlowpassprototype.Theeffectoffinitegain,finitebandwidth,andpathmismatchontheresonatorisanalyzed.ThefunctionoftheproposedresonatorandthedeviredequationsaboutpathmismatchhavebeenverifiedbyswitchedcapacitorsoftwareSWITCAP.
简介:Thispaperaimsatprovidinganuncertainbilevelknapsackproblem(UBKP)model,whichisatypeofBKPsinvolvinguncertainvariables.AndthenanuncertainsolutionfortheUBKPisproposedbydefiningPENashequilibriumandPEStackelbergNashequilibrium.Inordertoimprovethecomputationalefficiencyoftheuncertainsolution,severaloperators(binarycodingdistance,inversionoperator,explosionoperatorandbinarybacklearningoperator)areappliedtothebasicfireworksalgorithmtodesignthebinarybackwardfireworksalgorithm(BBFWA),whichhasagoodperformanceinsolvingtheBKP.Asanillustration,acasestudyoftheUBKPmodelandthePEuncertainsolutionisappliedtoanarmamentstransportationproblem.
简介:Toseekforlower-dimensionalchaoticsystemsthathavecomplextopologicalattractorstructurewithsimplealgebraicsystemstructure,anewchaoticsystemofthree-dimensionalautonomousordinarydifferentialequationsispresented.Thenewsystemhassimplealgebraicstructure,andcandisplaya2-scrollattractorwithcomplextopologicalstructure,whichisdifferentfromtheLorenz's,Chen'sandLu¨'sattractors.Byintroducingalinearstatefeedbackcontroller,thesystemcanbecontrolledtogenerateahyperchaoticattractor.Thenovelchaoticattractor,hyperchaoticattractoranddynamicalbehaviorsofcorrespondingsystemsarefurtherinvestigatedbyemployingLyapunovexponentspectrum,bifurcationdiagram,Poincar′emappingandphaseportrait,etc.,andthenverifiedbysimulatinganexperimentalcircuit.
简介:Anovelfinite-difference(FD)approximationinfrequency-domainfortheMurboundaryconditionispresentedinthispaper.CombinedwiththeFDequationsderivedforinhomogeneousanisotropicmedia,thisboundaryconditionisconvenientandeffectivetobeappliedtotheEMscatteringbyelectricallylargeobjectsofcomplexmedia.Boththememoryrequirementandthecomputingtimearedramaticallysaved,comparedwiththeMM,withthecompressedstoragetechnique.Forthecasesofdifferentmedia,RCSofcircularandrectangularcylindersarecomputed.Goodagreementisobtainedbetweentheresultsbythismethodandthoseavailable.
简介:Amongtheavailableclusteringalgorithmsindatamining,theCLOPEalgorithmattractsmuchmoreattentionwithitshighspeedandgoodperformance.However,theproperchoiceofsomeparametersintheCLOPEalgorithmdirectlyaffectsthevalidityoftheclusteringresults,whichisstillanopenissue.Forthispurpose,thispaperproposesafuzzyCLOPEalgorithm,andpresentsamethodfortheoptimalparameterchoicebydefiningamodifiedpartitionfuzzydegreeasaclusteringvalidityfunction.TheexperimentalresultswithrealdatasetillustratetheeffectivenessoftheproposedfuzzyCLOPEalgorithmandoptimalparameterchoicemethodbasedonthemodifiedpartitionfuzzydegree.
简介:Theterahertztime-domainspectroscopy(THz-TDS)systemandtherelatedtechnologyandtheapplicationsinCapitalNormalUniversityarepresented.ThemostoftenusedTHz-TDSsystemasaspectroscopicmeasurementsetupinourlabisintroducedindetail,includingtheTHzradiationsource,theTHzdetectionmethodanditsmeasurement,andthecontrolsystem.THzspectraofvariousmaterialsissummarizedanddiscussed.Thesematerialsincludebutnotlimitedtotwokindsoftypicalmatter—theillegaldrugsandexplosives.Thebiologicalmacro-molecules,cosmeticsandfinechemicalmaterials,ediblepigmentsandfoodadditives,homocysteicacidandrelatedcompounds,heavyionsinsoil,Chinesemedicines,tobaccoandcrops,oilandchemicalproducts,carbonnanotubes,superconductors,andvarioussemiconductorsandtheirheterojunctions,arepresented.THzemissionsfromtheInAsandInNsemiconductorssurfacearecompared.THzspectralinvestigationofmetallicmeshstructuresissummarized.Finally,anoutlookofTHzspectroscopicapplicationsisgiven.
简介:Basedonaclassofbipolarsequenceswithtwo-valuesautocorrelationfunctions,anewfamilyofbipolarsequencesisconstructedanditscorrelationspectrumiscalculated.ItisshownthatthenewfamilyisoptimalwithrespecttoWelch'sboundandisdifferentfromthesmallsetofKasamisequences,whilebothofthemhavethesamecorrelationproperties.
简介:Theforcesensingresistor(FSR)anditsconstructionandcharacteristicaredescribed.Byusingtheoptimalelectronicinterface,theendresultwhichisadirectproportionalitybetweenforceandvoltageisobtained.Thecircuitsofapplicationforforceandpositionmeasurementsintheroboticcontrolaregiven.TheexperimentthatFSRsareplacedonthefingersofBH-1dexteroushandastactilesensorstomeasurethecontactingforcesshowsFSR'sforcesensitivityisoptimizedforuseinthecontrolofrobotcontactingwithenvironment.
简介:Thecombineduseofthephotoelectricandelectro-opticpropertiesofBSOcrystal(Bi12SiO20)leadstorealizespatiallightmodulation.Undersomecondition,BSOcrystalcanbecomebirefringentdependingonalocalilluminance.Therelationshipbetweenthedistributionsofanilluminanceandabirefringencewillbediscussed.Thisspatiallightmodulatorcanworkinreal-time.Theexperimentshows,inordertoincreasethesensitivityofBSOcrystal,anelectricfieldof6kV/cmatanatmospherepressureof15×10^5PashouldbeappliedtoBSOcrystal.WithBSOwehavemeasured3-dimensionaldeformationbymeansofreal-timeholography.
简介:Compressivesensing(CS)hasemergedasanovelsamplingframeworkwhichenablessparsesignalacquisitionandreconstructionwithfewermeasurementsbelowtheNyquistrate.AnimportantissueforCSistheconstructionofmeasurementmatrixorsensingmatrix.Anewdeterministicsensingmatrix,namedasOOC-B,isproposedbyexploitingopticalorthogonalcodes(OOCs),BernoullimatrixandSingerstructure,whichhastheentriesof0,+1and-1beforenormalization.Wehaveproventhatthedesigneddeterministicmatrixisasymptoticallyoptimal.Inaddition,theproposeddeterministicsensingmatrixisappliedtodirectionofarrival(DOA)estimationofnarrowbandsignalsbyCSarrays(CSA)processingandCSrecovery.TheoreticalanalysisandsimulationresultsshowthattheproposedsensingmatrixhasgoodperformanceforDOAestimation.ItisveryeffectiveforsimplifyinghardwarestructureanddecreasingcomputationalcomplexityinDOAestimationbyCSAprocessing.Besides,lowerrootmeansquareerror(RMSE)andbiasareobtainedinDOAestimationbyCSrecovery.
简介:Byusingtwo-directionalS-roughsets,theconceptsof(f,f)-interferencegenerationand(f,f)-inter-ferencelawgenerationofknowledge,F-interferencegenerationandF-interferencelawgenerationoftwo-directionalS-roughsetsareproposed.Basedontheconceptsabove,therelationtheoremsbetweenF-interferencelossandF-interferencedegree,therelationtheoremsbetweenF-interferencelosslawandF-interferencedegreelaw,thediscernibilitytheoremsbetweenF-interferenceandF-interferencelawarepresented.Atlast,therecognitioncriterionofF-interferencelawanditsapplicationaregiven.
简介:Thecostfunctionforeigenstructuresextractionisdiscussedindetailinthispaper,onecanobtainthelargesteigenvectorbyminimizingthecostfunction.Inordertoobtainothereigenvectors,acovariancematrixseriesisconstructed.Ifonecomparesthecostfunctionwiththeenergyfunctionofaneuralnetworks,theneuralnetworkscanbeeasilyintroducedtoextracttheeigenvectors.Theoreticalanalysisandcomputersimulationsshowthattheproposedmethodisreasonableandfeasible.
简介:Ageneralizationofthelinguisticaggregationfunctions(oroperators)ispresentedbyusinggeneralizedandquasiarithmeticmeans.Firstly,thelinguisticweightedgeneralizedmean(LWGM)andthelinguisticgeneralizedorderedweightedaveraging(LGOWA)operatorareintroduced.Theseaggregationfunctionsuselinguisticinformationandgeneralizedmeansintheweightedaverage(WA)andintheorderedweightedaveraging(OWA)function.Theyareveryusefulforuncertainsituationswheretheavailableinformationcannotbeassessedwithnumericalvaluesbutitispossibletouselinguisticassessments.Theseaggregationoperatorsgeneralizeawiderangeofaggregationoperatorsthatuselinguisticinformationsuchasthelinguisticgeneralizedmean(LGM),thelinguisticOWA(LOWA)operatorandthelinguisticorderedweightedquadraticaveraging(LOWQA)operator.Wealsointroduceafurthergeneralizationbyusingquasi-arithmeticmeansinsteadofgeneralizedmeansobtainingthequasi-LWAandthequasi-LOWAoperator.Finally,wedevelopanapplicationofthenewapproachwhereweanalyzeadecisionmakingproblemregardingtheselectionofstrategies.
简介:Asatypicalcleanandrenewableenergy,windpowerisbecomingmoreandmorewidelyusedinelectricalindustry.However,itscharacteristicsofrandomandintermittenthavebroughtseriousproblemstothepowersystem,suchasvoltagefluctuationandinsufficientreactivepower.BasedontheK-meansclusteringalgorithm,thispaperclassifiesthedoubly-fedinductiongenerators(DFIG)accordingtotheoperationofpropellerpitchanglecontrol.Atthesametime,toobtaintheoptimalparameter,advancedparticleswarmoptimization(PSO)isused.ThenthedynamicmodelofDFIGunderthenetworkfaultconditionisbuilt.Whatismore,therolethatcrowbarcircuitplaysinlowvoltageridethrough(LVRT)isdiscussed.Finally,simulationsinDigSILENTverifythemodel.
简介:WiththedevelopmentofCMOSandMEMStechnologies,theimplementationofalargenumberofwirelessdistributedmicro-sensorsthatcanbeeasilyandrapidlydeployedtoformhighlyredundant,self-configuring,andadhocsensornetworks.Tofacilitateeaseofdeployment,thesesensorsoperateonbatteryforextendedperiodsoftime.Aparticularchallengeinmaintainingextendedbatterylifetimeliesinachievingcommunicationswithlowpower.Forbetterunderstandingofthedesigntradeoffsofwirelesssensornetwork(WSN),amoreaccurateenergymodelforwirelesssensornodeisproposed,andanoptimaldesignmethodofenergyeffcientwirelesssensornodeisdescribedaswell.DifferentfrompowermodelsevershownwhichassumethepowercostofeachcomponentinWSNnodeisconstant,thenewonetakesintoaccounttheenergydissipationofcircuitsinpracticalphysicallayer.Itshowsthattherearesomeparameters,suchasdatarate,carrierfrequency,bandwidth,Tsw,etc,whichhaveasignificanteffectontheWSNnodeenergyconsumptionperusefulbit(EPUB).Foragivenqualityspecification,howenergyconsumptioncanbereducedbyadjustingoneormoreoftheseparametersisshown.
简介:Thereexistsagreatdealofperiodicnon-stationaryprocessesinnatural,socialandeco-nomicalphenomenon.Itisveryimportanttorealizethedynamicanalysisandreal-timeforecastwithinaperiod.Inthisletter,awavelet-Kalmanhybridestimationandforecastingalgorithmbasedonstep-by-stepfilteringwiththereal-timeandrecursionpropertyisputforward.ItcombinestheadvantagesofKalmanfilterandwavelettransform.Utilizingtheinformationprovidedbymulti-sensoreffectively,thisalgorithmcanrealizenotonlyreal-timetrackinganddynamicmulti-stepfore-castingwithinaperiod,butalsothedynamicforecastingbetweenperiods,andithasagreatvaluetothesystemdecision-making.Simulationresultsshowthatthisalgorithmisvaluable.
简介:Superlatticesconsistingofalternatinglayersoforganic/polymericmaterialshavebeenfabricatedfromtris(8-hydroxyquinoline)aluminum(Alq3)andpoly(N-vinylcarbazole)(PVK)byamultisource-typehigh-vacuumorganicmoleculardeposition.ThecharacteristicsofsuperlatticestructuresaredeterminedbythesmallangleX-raydiffraction,opticaladsorptionandphotoluminescence.Theelectroluminescentdeviceswiththesuperlatticestructurehavealsobeenfabricatedandtheemissioncharacteristicsarediscussed.