简介：ＳｔｕｄｙｏｆｆｉｎｅｓｔｒｕｃｔｕｒｅｏｆｔｅｍｐｅｒａｔｕｒｅｉｎｔｈｅｅｑｕａｔｏｒｉａｌｗｅｓｔｅｒｎＰａｃｉｆｉｃＯｃｅａｎｗｉｔｈｗａｖｅｌｅｔｔｒａｎｓｆｏｒｍＪｉａｎｇＭｉｎｇｓｈｕｎ１ａｎｄＺｈａｎｇＡｉｊｕｎ（ＲｅｃｅｉｖｅｄＪｕ...

简介：Thewaveletpackettransformisusedforthedamagedetectionofoffshoreplatforms.Whensomedamageoccurs,thedynamicresponseparametersofthestructurewillshiftsubtly.However,insomecases,thedynamicparameters,suchasdynamicresponse,arenotsensitive,anditisverydifficulttopredicttheexistenceofdamage.Thepresentpaperaimstodescribehowtofindsmalldamagebytheuseofwaveletpackettransform.Asthewaveletpackettransformcanbeusedtoquicklyfindthesingularityoftheresponsesignalondifferentscales,theaccelerationsignalofadamagedoffshoreplatforminthetimedomainistransformedthroughthewaveletpacket.ExperimentalresultsshowthattheDaubechies4wavelettransformcanbeusedtodetectdamage.

简介：Homologousfeaturepointextractionisakeyproblemintheopticalandsyntheticapertureradar(SAR)imageregistrationforislands.Anewfeaturepointextractionmethodusingathresholdshrinkoperatorandnon-subsampledwavelettransform(TSO-NSWT)foropticalandSARimageregistrationwasproposed.Moreover,thematchingforthisproposedfeaturewasdifferentfromthetraditionalfeaturematchingstrategiesandwasperformedusingasimilaritymeasurecomputedfromneighborhoodcirclesinlow-frequencybands.Then,anumberofreliablymatchedcoupleswithevendistributionswereobtained,whichassuredtheaccuracyoftheregistration.ApplicationoftheproposedalgorithmtoSPOT-5(multi-spectral)andYG-1(SAR)imagesshowedthatalargenumberofaccuratelymatchedcouplescouldbeidentified.Additionally,bothoftherootmeansquareerror(RMSE)patternsoftheregistrationparameterscomputedbasedontheTSO-NSWTalgorithmandtraditionalNSWTalgorithmwereanalyzedandcompared,whichfurtherdemonstratedtheeffectivenessoftheproposedalgorithm.Thealgorithmcansupplythecrucialstepforislandimageregistrationandislandrecognition.