简介:Tomakeaudiowatermarkingaccomplishbothcopyrightprotectionandcontentauthenticationwithlocalization,anovelmultipurposeaudiowatermarkingschemeisproposedinthispaper.Thezero-watermarkingideaisintroducedintothedesignofrobustwatermarkingalgorithmtoensurethetransparencyandtoavoidtheinterferencebetweentherobustwatermarkandthesemi-fragilewatermark.ThepropertyofnaturalaudiothattheVQindicesofDWT-DCTcoefficientsamongneighboringframestendtobeverysimilarisutilizedtoextractessentialfeaturefromthehostaudio,whichisthenusedforwatermarkex-traction.And,thechaoticmappingbasedsemi-fragilewatermarkisembeddedinthedetailwaveletcoefficientsbasedontheinstantaneousmixingmodeloftheindependentcomponentanalysis(ICA)system.Boththerobustandsemi-fragilewatermarkscanbeextractedblindlyandthesemi-fragilewatermarkingalgorithmcanlocalizethetamperingaccurately.Simulationresultsdemonstratetheeffectivenessofouralgorithmintermsoftransparency,security,robustnessandtamperinglocalizationability.
简介:Anaudiorecoveringmethodofspread-spectrumhiddeninformationisproposedbasedongeneticalgorithm.Inthismethodtheembeddedsequencelengthisconfirmedfirstly,thenthebestestimatedsequencewiththeconfirmedlengthisgotbygeneticalgorithm,finallytheconfidentialmessagehiddeninstego-audiocanberecovered.Usingthisapproach,thehiddeninformationcanberecoveredwithoutanyinformationfromthetransmitter.ThepresentedmethodhasbeenimplementedonPC,andtheexperimentalresultsshowthattheaveragerecoveringcorrectrateishigherthan90%.
简介:Wereportthefabricationprocessofpiezoelectriccellulosepaperandtheenhancementmethodofitspiezoelectricproperty.Stretchingmethodwithdifferentwet-drawingratioswasintroducedtoincreasethepiezoelectricpropertyofcellulosepaperduringregenerationprocess.ItisobservedthattheYoung’smodulusandthepiezoelectricchargeconstantsareverydependentonthedrawingratioandthedirectionofnanofibrilsofpiezoelectricpaper.Usingtheenhancedpiezoelectricproperty,weprovethattheflexibleregeneratedpiezoelectriccellulosecanbeappliedtothepotentialacousticapplicationssuchasthinpiezoelectricpaperspeaker.
简介:Anew,simpleandefficientfiberaudiotransmissionmethodforthelongdistancesecurecommunicationispresented,whichperformssignalmodulationbythestrain-opticeffectsandsignaldemodulationbytheall-fiberinterferometer.Theinterferometerisatrulypath-matcheddevice,whicheliminatesmuchoftheundesirablenoisebycombiningthereferenceandthesensingarmswithinthesameopticalfiber.Thesinusoidalsignalsadoptedintheexperimentareinafrequencyrangeof300HZ-3400HZandofthemulti-frequency,andthesystemshowsgoodcapabilities,robustsecurityandmaintenanceofaudiointegrity.Thedevicemaybeapplicableinthefieldofpointtopointsecurecommunicationof40kilometerlongtransmissionrange.
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简介:这份报纸在一个交流磁场与磁性的磁滞现象和机械活动性在小铁磁性的粒子的暂停在magnetodynamics和精力驱散上论述理论、试验性的研究。由在固体,液体或煤气的环境推迟并且使遭到了到高频率磁场的粒子的精力吸收具有为由过高热,化学技术,生物工学和聪明的材料科学的癌症治疗的大兴趣。在液体驱散的亚微米像针的-Fe2O3粒子与多达105A/m的紧张在这研究受到430Hz磁场。动态磁化环在平行被测量到在样品浪费的体力。粒子分散的联合magnetomechanical动力学被使用允许的一个chain-of-spheres模型模仿支离破碎的磁场颠倒。在液体分散,在千赫频率范围以内,粒子的机械活动性不防碍他们使热版本可比较到那的磁性的颠倒与固体观察了的hysteretic;例如,在用-Fe2O3的现在的学习,在液体的粒子使遭到了到展出的热版本每干燥粒子内容的1cm3从250评估直到600W的104Hz地。