简介:Asimplifiedthree-dimension(3D)fadingchannelmodeldeployedinamulti-inputmulti-output(MIMO)beamformingsystemisexploredinthisarticle.Bothangleofarrival(AoA)andangleofdeparture(AoD)whichimpacttheoverallsystemperformanceareexamined.Thenumericalresultsaregivenforvalidatingtheaccuracyofthetheoreticalderivedformulas.Furthermore,theperformancesofthemodelwithdifferentnumberoftransmittersandreceiversarestudiedandcompared.TheincrementinAoAparametersdefinitelygeneratestheimpactofthesystemperformancewhentheconsiderationofsimplified3Dchannels.
简介:TheIsodynetechniquebasedonthescatteredlightscanningfromathinlaserbeamcanbeusedtoobtaintheinformationinsidetheloadedobjectintheroomtemperaturenondestructively,soitisaverypowerfultechniquein3Dstressanalysis.Theproblemsarehowtointerprettheinformationandhowtogetsufficientinformationfromthefewinterferencefringe.Birefringencephaseshifttechniquecandistinguishthefringeordersautomaticallyandenrichtheinformationin256graylevelsbetweenmaximandminimlightintensity.InthepapertheIsodynebirefringencephaseshiftmethodwithanobliqueincidenceandequilibriumequationispresented,bywhichthe3DstressesinthemiddleplaneofaplatewithUshapenotchareseparatedsuccessfully.
简介:SegmentationandedgeregulationarestudieddeeplytoextractbuildingsfromDSMdataproducedinthispaper.Buildingsegmentationisthefirststeptoextractbuildings,andanewsegmentationmethod-adaptiveiterativesegmentationconsideringratiomeansquare-isproposedtoextractthecontourofbuildingseffectively.Asub-image(suchas50×50pixels)oftheimageisprocessedinsequence,theaveragegraylevelanditsratiomeansquarearecalculatedfirst,thenthresholdofthesub-imageisselectedbyusingiterativethresholdsegmentation.Thecurrentpixelissegmentedaccordingtothethreshold,theaver-agegraylevelandtheratiomeansquareofthesub-image.Theedgepointsofthebuildingaregroupedaccordingtotheazimuthofneighborpoints,andthentheoptimalazimuthofthepointsthatbelongtothesamegroupcanbecalculatedbyusinglineinterpolation.
简介:Awhole-field3Dsurfacemeasurementsystemforsemiconductorwaferinspectionisdescribed.Thesystemconsistsofanopticalfiberplate,whichcansplitthelightbeamintoN2subbeamstorealizethewhole-fieldinspection.Aspecialprismisusedtoseparatetheilluminationlightandsignallight.Thissetupischaracterizedbyhighprecision,highspeedandsimplestructure.