简介:Toquicklyobtainaccurate3Ddataofdentalcastmodel,thispaperproposesa3Dreconstructionmethodfordentalcastmodelbasedonstructuredlight.Thismethodcombinesthestructuredlightwiththemotorturntabletoobtainagroupof3Ddataforthedentalcastmodelfrommultipleangles,andautomaticallyregistersthedental3Ddatafrommultipleanglesthroughtheballcalibrationofturntable.Comparedwiththerealdataofthedentalcastmodel,themaximumerrorofthe3Dreconstructionresultsinthispaperis0.115mm.Thereconstructiontimeofthisprocessisabout130s.Theexperimentalresultsshowthatthemethodhashighprecisionandhighscanningspeedforthe3Dreconstructionofthedentalcastmodel.
简介:Doubledataratesynchronousdynamicrandomaccessmemory(DDR3)hasbecomeoneofthemostmainstreamapplicationsincurrentserverandcomputersystems.Inordertoquicklysetupasystem-levelsignalintegrity(SI)simulationflowfortheDDR3interface,twosystem-levelSIsimulationmethodologies,whichareboard-levelS-parameterextractioninthefrequency-domainandsystem-levelsimulationassumptionsinthetimedomain,areintroducedinthispaper.BycomparingtheflowofSpeed2000andPowerSI/Hspice,PowerSIischosenfortheprintedcircuitboard(PCB)board-levelS-parameterextraction,whileTektronixoscilloscope(TDS7404)isusedfortheDDR3waveformmeasurement.Thelabmeasurementshowsgoodagreementbetweensimulationandmeasurement.ThestudyshowsthatthecombinationofPowerSIandHspiceisrecommendedforquicksystem-levelDDR3SIsimulation.