简介：The’polarcoding’proposedbyDr.Arkancanachievethesymmetriccapacityofbinary-inputdiscretememorylesschannels(B-DMC).ThegeneratormatrixofpolarcodesisGN=BNFnforN=2n,BNwasapermutationmatrix.Inthearticleitwasrealizedwithaninterleaver,sothematrixproductionofGNwasavoided;thenthegeneratormatrixwasjustdeterminedbythematrixFnwhichwasconstructedwiththreesub-matrixesofFn-1andone2N-1orderzeromatrix,itwasdealwithfastHadamardtransform(FHT)algorithm.Thecomplexityofthenewschemewasreducedsharply,andaniterativealgorithmalsocanbeused.TheexampleshowedthatwhenN=8,complexityoftheencodingschemewasjust16whichisobviouslylessthanthatoforiginalencodingscheme36.

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简介：Losslessdatahidingcanrestoretheoriginalstatusofcovermediaafterembeddedsecretdataareextracted.In2010,Wangetal.proposedalosslessdatahidingschemewhichhidessecretdatainvectorquantization(VQ)indices,buttheencodingstrategiesadoptedbytheirschemeexpandthefinalcodestream.ThispaperdesignsfourembeddingandencodingstrategiestoimproveWangetal.'sscheme.TheexperimentresultoftheproposedschemecomparedwiththatoftheWangetal.'sschemereducesthebitratesofthefinalcodestreamby4.6%andraisesthepayloadby1.09%onaverage.

简介：Theresearchandapplicationofwirelesslocalareanetworks(WLAN)technologyareinastageofrapiddevelopment.Ithasbeenoneofresearchfocusesofthewirelesscommunicationsfield.Throughtheuseofenhancedsingle-user(SU)/multi-user(MU)multipleinputmultipleoutput(MIMO)-orthogonalfrequencydivisionmultiplexing(OFDM)technology,thenextgenerationWLANIEEE802.11acdramaticallyincreasesthethroughput.AnimprovedMIMO-OFDMschemebasedonmodulationdiversityisproposedforthenextgenerationWLAN.Itusestwo-dimensionalmodulationdiversitytothecurrentIEEE802.11actransmissionscheme.Throughthespace-time-frequencycomponentinterleaverandtherotationalmodulation,theproposedschemeexhibitshighspectralefficiencyandlowerrorrateinfadingchannels.ThesimulationresultsshowthattheproposedschemesignificantlyoutperformstheSU/MUMIMO-OFDMschemeinthecurrentIEEE802.11acstandard,whichisupto5dB.

简介：Thebettercompressionratecanbeachievedbythetraditionalvectorquantization(VQ)method,andthequalityoftherecoveredimagecanalsobeaccepted.Butthedecompressedimagequalitycannotbepromotedefficiently,sohowtobalancetheimagecompressionrateandimagerecoveringqualityisanimportantissue.Inthispaper,animageistransformedbydiscretewavelettransform(DWT)togenerateitsDWTtransformedimagewhichcanbecompressedbytheVQmethodfurther.Besides,wecomputethevaluesbetweentheDWTtransformedimageanddecompressedDWTtransformedimageasthedifferencematrixwhichistheadjustablebasisofthedecompressedimagequality.Bycontrollingthedeviationofthedifferencematrix,therecanbenearlylosslesscompressionfortheVQmethod.ExperimentalresultsshowthatwhenthenumberofcompressedbitsbyourmethodisequaltothenumberofthosebitscompressedbytheVQmethod,thequalityofourrecoveredimageisbetter.Moreover,theproposedmethodhasmorecompressioncapabilitycomparingwiththeVQscheme.

简介：Recently,Changetal.proposedaSudoku-basedsecretimagesharingscheme.TheyutilizedtheSudokugridtogeneratemeaningfulshadowimages,andtheirschemesatisfiedallessentialrequirements.BasedonChangetal.'sscheme,weproposeanovel(n,n)secretimagesharingschemebasedonSudoku.Intheproposedscheme,asecretimagecanbesharedamongndifferentcoverimagesbygeneratingnshadowimages,andthesecretimagecanbereconstructedwithoutdistortionusingonlythesenshadowimages.Also,theproposedschemecansolvetheoverflowandunderflowproblems.Theexperimentalresultsshowthatthevisualqualityoftheshadowimagesissatisfactory.Furthermore,theproposedschemeallowsforalargeembeddingcapacity.

简介：InAugust2011,theSangzhiCountygovernment,HunanProvince,adoptedaseriesofnewhealthcarepoliciesasanationalpilotoftheNewCooperativeMedicalScheme(referredtoas2011NCMS).Thesepoliciesweredesignedtofurtherresolveillness-ledpovertyandthepoorstateofhealthcareinthelocalarea.TheprogramhadapositiveimpactandspreadtootherregionsinHunanProvince.Thispaperwilldiscusstheprogressmadeasaresultofthepoliciesandseveralissuesthatchallengetheschemeinpractice.Atotalsampleof1212individualsand303householdswereincludedintheanalysis,and98interviewswereconductedwithpeoplerelatedtothescheme.Ourmajorfindingsindicatethatthe201!NCMShassignificantlyreducedtheout-of-pocketmedicalpaymentofruralresidents,andalsoincreasedthetownshiphospitals’patientflow.However,themedicalschemestillfacesmanychallengingissuesduringtheimplementation.WiththeincreasinginterestamongtheChinesepolicymakersinstrengtheningandpromotingtheSangzhiModel,theimpactsoftheschemedeservegreaterattentioninpracticesoastofurtherimproveNCMSinruralChina.

简介：Distortion-freedataembeddingisatechniquewhichcanassurethatnotonlythesecretdataiscorrectlyextractedbutalsothecovermediaisrecoveredwithoutanydistortionaftersecretdataisextractedcompletely.Becauseoftheseadvantages,thistechniqueattractstheattentionofmanyresearchers.Inthispaper,anewdistortion-freedataembeddingschemeforhighdynamicrange(HDR)imagesisproposed.BydependingonCartesianproduct,thisschemecanobtainhigherembeddingcapacitywhilemaintainingtheexactlyidenticalcoverimageandstegoimagewhenusingthetonemappingalgorithms.Inexperimentalresults,theproposedschemeissuperiortoYuetal.'sschemeinregardtotheembeddingrate?anaverageembeddingrateof0.1355bppcomparedwithYuetal.'sscheme(0.1270bpp).

简介：Inthispaper,ahybridadaptivecompensationcontrolschemeisproposedtocompensatethefrictionoccurrenceandothernonlineardisturbancefactorsthatexistinthehigh-precisionservosystem.Anadaptivecompensationcontrollerwithadual-observerstructureisdesigned,whiletheLuGredynamicfrictionmodelwithnon-uniformparametricuncertaintiescharacterizesthefrictiontorque.Consideringtheinfluenceoftheperiodicdisturbancetorqueandparametricuncertainties,fuzzysystemsandarobusttermareemployed.Inthisway,thewholesystemcanbetreatedasasimplelinearmodelafterbeingcompensated,thentheproportional-derivative(PD)controllawisappliedtoenhancingthecontrolperformance.OnthebasisofLyapunovstabilitytheory,theglobalstabilityandtheasymptoticconvergenceofthetrackingerrorareproved.Numericalsimulationsdemonstratethattheproposedschemehaspotentialstorestraintheimpactofdisturbanceandimprovingthetrackingperfor

简介：Informationhidingschemesbasedonvectorquantization(VQ)usuallyrequirelengthyVQencodinganddecodingprocesses.Inthispaper,weproposeanefficientinformationhidingmethodbasedonclosestpairedtreestructurevectorquantization(CPTSVQ).Thesimulationresultshowsthattheexecutiontimeoftheproposedschemeismuchshorterthanthatattainedbypreviousapproaches.

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简介：Steganographyisatechniquethatconcealssecretdataintoacovermediumfordeliveringsecretdataoverpubliccomputernetworks.Reversibledatahidingschemesnotonlycanachievesecretdatadelivery,butalsocanrestorethecovermedium.Histogramshiftingisoneofthemostpopularreversibledatahidingtechniques.Luoetal.presentedareversibledatahidingtechniquethatshiftsthehistogramofpredictionerror.ButtheembeddingpayloadofLuoetal.'smethodcanfurtherbeimproved.Theproposedmethodusesadifferencesegmentationstrategyandpseudopixelgenerationtoincreasetheheightofpeakinthepredictionerrorhistogram.TheexperimentalresultsshowthattheembeddingpayloadoftheproposedmethodishigherthanthatofLuoetal.'smethod.

简介：追踪作为多尺度知道的算法追踪雷达的新雷达回响回应由跨关联(MTREC)在这研究被开发在不同空间规模分析雷达回响的运动。雷达回响的运动，特别地与对流暴风雪联系了，在导致对流暴风雪的形成的气象学的系统之中由于复杂相互作用在各种各样的空间规模展出不同特征。为空回响区域，平常的关联技术生产零或运动向量的很小的大小。减轻这些限制，MTREC由关联(TREC)使用追踪的雷达回响有一个大盒子的技术驾驶风驾驶的系统的运动，和MTREC与一个小盒子使用TREC技术决定估计小规模的内部运动向量。最后，MTREC向量被综合获得系统的运动和小规模的内部运动。MTREC技术的性能与用案例研究的TREC技术相比：Wenzhou雷达和一个嚎啕线系统在2005年9月11日在2011年6月23日观察的Khanun台风由北京雷达检测了。结果证明那更空间地变光滑，连续向量领域能被MTREC技术产生，它在追踪全部雷达反射率模式导致改进。新多尺度的追踪计划被使用在量的降水nowcasting的表演上学习它的影响。在一1-h铅时间的重降水的地点和紧张与使用雷达和雨计量器的量的降水估计更一致。

简介：Networkcodingbringsmanybenefitsformulticastnetworks.Itisnecessarytointroducenetworkcodingintoopticalnetworks.Nevertheless,thetraditionalnetworkcodingschemeishardtobeimplementedinopticalnetworksbecauseoftheweakoperationcapabilityinphotonicdomain.Inthepaper,wefocusedonrealizingtwo-channelnetworkcodinginall-opticalmulticastnetworks.AnopticalnetworkcodingschemewhichcanberealizedvialogicshiftandlogicXORoperationsinphotonicdomainwasproposed.Moreover,toperformthenetworkcodingschemethecodingnodestructurewasdesignedandtheoperationprincipleandprocesseswereillustratedindetail.Intheendofthepaper,theperformanceandthecostofdifferentall-opticalmulticastmodewerecomparedandanalyzed.

简介：Thispaperaddressestheissueofreal-timedatatransmissioninvehiclestoroadside(V2R)environmentbythehybridcoordinationfunction(HCF)ofcontrolledchannelaccess(HCCA)specifiedbytheIEEE802.11pstandard.HCCAisoneofthemediumaccessmechanismsintheIEEE802.11standard,andusesthepollingschemesimilartothepointcoordinationfunction(PCF)toprovidereliablequalityofservice(QoS),whichmaycauseresourceovershootingandhightimeconsuming.ThispapertriestoimprovetheperformanceoftheHCCApollingschemeanddesignsnewdatatransmissionschedulingscheme.Thesimulationresultsoftheproposalarecomparedwiththoseofthestandardstrategy.SimulationresultsdemonstratethattheimprovedHCCAhaslowerdelay,lossrate,andhigherthroughputthanthoseofthestandardone.

简介：WeproposeaschemeformitigatingRayleighbackscatteringnoiseanddemodulatingdifferentialphaseshiftkeying(DPSK)signalsinwavelength-division-multiplexedpassiveopticalnetworks(WDM-PONs)withinjection-lockedFabry-Perotlaserdiodes(FP-LDs).SignaldemodulationandwavelengthconversionaresimultaneouslyrealizedonthebasisofthefrequencydeviationandredshiftoflongitudemodesintheFP-LDs.Experimentalresultsdemonstratethatthedemodulationandwavelengthconversionof2.5-Gb/sDPSKsignalsareachieved.Apowerpenaltyofabout1.6dBatabiterrorrateof109ismeasuredaftertransmissionover25-kmsinglemodefiber.

简介：Arraygainwouldbewellexploitedtoimprovepowercoverageifsomepowerfulmultipathcomponentsfromdifferentradiolinkscancoherentlycombineatthereceiver(Rx).Thus,inthispaper,analgorithmisproposedfortransmissioninsimulcastsystem,wherepartialchannelstateinformation(CSI)isneeded.Basedonmeasuredmultipathchannel,performanceoftheproposedalgorithmisevaluated.Accordingtosimulationresults,theproposedalgorithmoutperformsthedirectionsummation(DS)schemeandmultipathantennadiversity(MAD)algorithm,with2～4dBadvantageoverthelatters.Especiallyinlineofsight(LOS)scenario,theadvantageismoreobvious.Besides,theproposedalgorithmbringsmoregainwithincreasingnumberoftransmitantennaswithoutadditionalpower.Finally,robustnessoftheproposedalgorithmisexaminedwithimperfectCSI.

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简介：Orthogonalfrequencydivisionmultiplexing(OFDM)whichhasbeenadoptedinthelong-termevolution(LTE)systemcanimprovethesystemcapacityobviously.However,italsobringsaboutsevereinter-cellinterference(ICI)forcell-edgeusers(CEUs).Totacklethisproblem,multi-userselectionandpowercontrol(MuS-PC)isproposedasanefficientschemeinuplinkcoordinatedmulti-pointmulti-usermulti-inputmulti-output(CoMP-MU-MIMO)transmission/reception.Thispaperjointlyconsidersuser’ssignaltointerferenceplusnoiseratio(SINR)andproportionalfairness(PF)tomaximizethetotalchannelcapacityinmulti-userselectionbyformulatingapenaltyfunction.Tosimplifythepenaltyfunction’scomputation,particleswarmoptimization(PSO)algorithmisintroduced.Inaddition,powercontrolisadoptedtomaximizeoverallenergyefficiency.SimulationresultsdemonstratethattheMuS-PCschemecannotonlyobtaintheoptimaltotalchannelcapacitywhileguaranteeeachuser’squalityofservice(QoS)andPF,butalsolargelyreducecomputationalcomplexityandimproveenergyefficiency.Asaresult,thepoorcommunicationqualityofCEUscanbeenhanced.