简介：Regardforthefuzzinessandtherandomnessinsomeacousticfields,amethodforthenumericalanalysisofthe2DacousticfieldwithFuzzy-Randomparameterswasproposedbasedontheequivalentconversionofinformationentropy.Intheproposedmethod,afuzzyrandomacousticfieldwastreatedasapurefuzzyacousticfieldorapurerandomacousticfieldbytransformingallthevariablesintofuzzyvariablesorrandomvariables.Perturbationfiniteelementmethodsforanalyzingthetwo-dimensionalacousticfuzzyandrandomfieldarededuced.Thesoundpressureresponseofa2Dacoustictubeandthe2Dacousticcavityofacarwithfuzzy-randomparameterswereanalyzedbytheproposedmethodandtheMonteCarlomethod,theresultsshowthattheproposedmethodcanbewellappliedtothenumericalanalysisofthe2Dacousticfieldwithfuzzy-randomparameters,andhasgoodprospectofengineeringapplication.

简介：Foraccuracyandrapidityofaudioeventdetectioninthemass-dataaudioprocessingtasks,agenericmethodofrapidlyrecognizingaudioeventbasedon2D-HaaracousticsuperfeaturevectorandAdaBoostisproposed.Firstly,itcombinescertainnumberofcontinuousaudioframestobean'acousticfeatureimage',secondly,usesAdaBoost.MHorfastRandomAdaBoostfeatureselectionalgorithmtoselecthighrepresentative2D-Haarpatterncombinationstoconstructsuperfeaturevectors;thirdly,analyzesthecommonalityanddifferencesbetweensubcategories,thenextractscommonfeaturesandreducesdifferentfeaturestoobtainagenericaudioeventtemplate,whichcansupporttheaccurateidentificationofmultiplesub-classesanddetectandlocatethespecificaudioeventfromtheaudiostreamaccurately.Experimentalresultsshowthattheuseof2D-Haaracousticfeaturesupervectorcanmakerecognitionaccuracy5%higherthanonesthatMFCC,PLP,LPCCandothertraditionalacousticfeaturesyielded,andcanmakethetrainingprocessing7-20timesfasterandtherecognitionprocessing5-10timesfaster,itcanevenachieveanaverageprecisionof93.38%,anaveragerecallof95.03%undertheoptimalparameterconfigurationfoundbygridmethod.Aboveall,itcanprovideanaccurateandfastmass-dataprocessingmethodforaudioeventdetection.

简介：TheevaluationofcreepdamagesofCr-Mo-Vsteelusedinthegasturbineofpowerplanthasbeencarriedoutusingtheline-focus-beam(LFB)acousticmicroscopy.Thevelocityofleakysurfaceacousticwave(LSAW)propagatednearthespecimensurfacewasusedforthequantitativeevaluations,whichwasmeasuredbyLFBacousticmicroscopyusingthev(z)curveanalysismethod.IthasbeenshownthatwiththeincreaseofcreepdamagefractionofmetalmaterialtheLSAWvelocitydecreasesobviously,whichsuggeststhepossibilityofnondestructiveandquantitativeevaluationsofcreeddamagesinmetalmaterialsbyacousticmicroscopy.

简介：Anewapproachtodeterminealltheelectro-elasticconstantsofthepiezoelectriccrystalsinclass4mmhasbeenputforward.Asanexample,alltheconstantsofLithiumTetraborate（Li2B4O7）crystalhavebeenmeasuredbymeansoftheapproach.Theoutstandingadvantageoftheapproachisthatiton-lyneedstoemployinmeasurementthreecrystalplatesdifferentlyoriented.

简介：Simpleandefficientsurfaceacousticwave(SAW)two-portresonatorswithlowinsertionlossandhighQ-valuesonST-Xquartzsubstrateusingacorrosion-proofA1/Au-stripeelectrodestructurearedevelopedforgassensing.Itwascomposedoftwoshortedgratingreflectorsandadjacentintedigitaltransducers(IDT),andanactivemetalfilminthecavitybetweentheIDTsforthesensitivefilmcoating.Thedevicesareexpectedtoprovidegoodprotectiontowardsmetalelectrodeforgassensorsapplicationinchemicallyreactiveenvironments.Excellentdeviceperformanceaslowinsertionloss,highQfactorandsingle-modeareachievedbycarefullyselectingthemetallicelectrodethickness,cavitylengthandacousticaperture.Priortofabrication,thecouplingofmodes(COM)modelwasperformedfordevicesimulationtodeterminetheoptimaldesignparameters.Thefabricatedsingle-modeSAWresonatoratoperationfrequencyof300MHzrangeexhibitsmatchedinsertionlossof~6.5dBandloadedQfactorinthe3000range.Usingthefabricatedresonatorasthefeedbackelement,adualresonator-oscillatorwithexcellentfrequencystability(0.1ppm)wasdevelopedandevaluatedexperimentally,anditissignificantforperformanceimprovementofSAWgassensor.