简介:Inthisdissertation,sereralkeyproblemsinthefieldofsteganographicimagesecurityaremainlystudiedanddiscussed:(1)Anovelkindofimagecryptosystemisstudied.Theencryptedinformationofsecretimageisembeddedintoanordinaryimage,whichcanbetransmittedpublicly,anditwillnotcauseattentionofillegaleavesdropper.Thefollowingresultsareachieved:(a)Theimagehidingalgorithmanditsimprovedalgorithmbasedonwavelettransformandvectorquantizationareproposed,andbothalgorithmsembedthesecretimageaftertakingfulladvantageofwavelettransform(WT)tocompressit.(b)IntroducingtheCDMAconceptincommunicationtheory,anovelkindofimagecryptosystem—imagehidingcryptosystemofimagedivisionmultipleaccessisproposed.Weencryptkeyinformationofseveralsecretimagesandthenhidethemintoanimage,whichisanordinaryimage.Afterreceiversgettheimage,eachreceivercanrestorecorrespondingsecretimageindependently.Comparedwithotherimageencryptionalgorithms,ournewimagehidingcryptosystemcancompresssecretimagedataefficiently.Moreover,thesecurityandpracticabilityofoursystemisbetter.(2)Digitalwatermarkingisthemostimportantbranchofinformationhiding,whichhasbeenthehotspotofinternationalacademia.Digitalwatermarkinghasbeenproposedasasolutiontotheproblemofcopyrightprotectionofmultimediadocumentsinnetworkedenvironments.Inthisfield,thefollowingresultsareachieved:(a)AnewfrequencyinformationhidingandwatermarkingalgorithmbasedonWTandDiscreteCosineTransform(DCT)ispresented.AftercompressedbyWT,theinformationofsecretimageisembeddedintoDCTdomain.ThealgorithmhasgoodimperceptibilityandsecurityandisrobustagainstJPEGcompressingandcropping.Thealgorithmcanbeusedtoembedwatermarkintoimages,andthewatermarkmaybeone256-colorpictureormoreandmorethanonesecretimagecanbehiddenintoasinglecarrierimage.(b)Anovelwatermarkingalg
简介:Thispapermainlydiscussesthe"double-trackcharge"system(priceprejudicechargesystem)intheoryandpractice.Theauthorexplainsandanalyzesthe"differentialchargesphenomenon"ofuniversitiesinChinabytaking"Paretooptimality"asregulationstandardand"Darwinoptimality"asempiricalstandard,combiningregulationstandardwithpracticestandard,realisticstandardofvaluejudgmentwithultimatestandard,andfairnesswithefficiency.Thispaperprovidestheoreticalreferenceandanoperationplatformforapplicationandimplementationdifferentialchargesandthecontainmentofcorruptionincollegeenrollment.
简介:Anin-depthexplorationhasbeenmadeoftelecommunicationtariffanditsdecisionsupportsystem.Itisthefirstattempttoconductsuchastudybytheintegrateduseofeconometrics,systememulationandsystemdynamics.Apractically-demandedcostmodelofthetelecommunicationtariffdecisionisproposed.Thesystemhasbeenverifiedwithrealdata.
简介:Thepricingoftelecommunicationservicesisquiteimportantaswellascomplicated.ThispaperstrengthenstheresearchoftheoriesandimplementationoftelecommunicationtariffinChina.Itishelpfulforthegovernmentauthoritiesandenterprisestounifyandstandardizetheregulatorymethods,toguidethedecidingofthestructureandleveloftelecommunicationtariffbyimplementingscientifictheories,tofurtherdevelopandoptimizethetariffsystem.Thispaperconductsasystematic,in-depthandcreativeresearchonsomeofthemostpopularandmostdifficultproblemsintheareaoftelecommunicationtariffresearch,suchastheregulationoftelecommunicationtariff,thetheoriesoftelecommunicationtariff,thesystematicpricingtheory,theinterconnectioncharge,themodelcostevaluationtheory,thelong-runincrementalcosttheory,andtheinternationaltelecommunicationtariff.Afterstudyingtheforeignmethodsontelecommunicationtariffregulation,basingonthecurrentsituationofChina'stariffregulation,thescopeandmethodsforChina'stelecommunicationtariffregulationaresuggested.Aimedattheweaknessofpricingtheoryforenterprisestosetuptelecommunicationtariffs,anoverallframeworkoftelecommunicationtarifftheoriesisproposed.Thesystematicpricingtheoryandmodelcostevaluationtheoryoftelecommunicationservicesareputforwardfromabrandnewperspective.Afronttopic,theLRICtheory,isprobed.Inaddition,thepricingpracticesofnetworkinterconnectionchargeandinternationaltelecommunicationtariff,whicharecurrentlyveryattractivetothetheorists,arediscussed.Basingonthesestudies,thispaperimprovesthestructureoftelecommunicationtarifftheory.ItprovidestheChinesegovernmentauthoritieswithpracticalmethodsandhelpfulsupportstoregulatethetelecommunicationtariffs;inthemeantime,italsoprovidestheenterpriseswithscientificpricingtheoriesandmethodstosetuptelecommunicationtariffs.Overall,thispaperhasnot
简介:Fromaneconomicangle,thispaperanalyzesanddemonstratestheirrationalityofthecurrentInternetsettlementofInterconnection;thenpointsoutthattheheavychargesforInternetinterconnectionfromdevelopingcountriestothedevelopedcountrycanbethoughtofasoneofthemainandkeyreasonsthatrestrictthebalanceddevelopmentoftheInternetintheworld,whichcausestheintensificationof'digitaldivide',widensthegapbetweenpoorandrichcountriesandfurtheraggravatesthedisequilibriumoftheglobaleconomicdevelopment;andthustheconclusionisreached:thepublicpolicyselectionshouldbemadebythewholeinternationalsocietyjointlyforpayingcloseattentionandregulatingsettlementsystemsofInternetinterconnectiontodwindle'digitaldivide'throughouttheworld.
简介:Accuratetimedelayestimationisveryimportantinmultichannelnoisesuppressionsystems.Thispaperhasproposedanewmethodtoreducetheeffectofnoiseontheestimationoftimedelaybetweendifferentchannels.Ournewtimedelayalgorithmwillmoreconsiderablyreducetheestimationerror,comparedwiththeconventionalautocorrelationfunctionmethod.
简介:Thearticlestudiestheinternationalfinancialservice,whichmightbeopenedbyChinaPost.Basedondefiningpostalfinancialservice,itanalysestheface-to-facecircumstancesandchallengesbyusingthemethodofnormalmarketpositionandthemethodofGeneralElectricCompany(GEC).FinallyitdefinesthemarketpositionofPostalFinancialInternationalService(PFIS).
简介:EncryptedCommunicationtechniqueisanimportantmeasuretotheinformationsafety.BasedontheadvantagesoftwopublicencryptionalgorithmRSA&DES,anovelhighintensitypublicencryptionalgorithmChaosRandomHighIntensity(CHR)isproposedinthispaper.TheprincipleofCRHisdescribedandanalyzedindetail,andtheresultsofcomputersimulationhasproveditseffectivenessandcorrectness.
简介:Thedissertationstudiesthearchitectureofbroadbandintelligentnetwork(BIN)andimplementationofvideoconferencebasedonATMnetworkandofmulticastroutingproblemonvideoconferenceusingBINundertheaidoftheimportanttask-StudyofINandB-ISDNIntegration(69896244)-sponsoredbyNationalNaturalScienceFund.Alotofpointsofviewandsolutionsarepresent.Themaincontributionsinthedissertationareasfollows:(1)DesignthenewarchitectureofBINandimprovethearchitectureofBINproposedbyITU-T.ItiseasytosetuptheconnectionsofvideoconferenceusingthenewarchitectureofBIN.(2)PresentthedetailedschemethatBINcontrolsandimplementsvideoconferencewithoutspecializedresourcefunction,studytheschemeofallthemediaonvideoconferencetransmittedandswitchedunderthecontrolofBIN,anddiscusshowtoimplementpoint-to-multipointcommunicationsusingBIN.(3)FirstpresenttheschemeofimplementingmulticastroutingalgorithmsonvideoconferenceusingBIN.(4)Explicitlyintroduceaseriesofconceptsincludingneighboringnode,neighboringnodeset,neighboringedge,thenproposeanAdjustableDynamicMulticast(ADM)routingalgorithmwhichissuitableforvideoconference,analyzeitsperformances,andprovethealgorithmisappropriateandfeasible.(5)Developadegree-constraineddynamicmulticast(DADM)routingalgorithmwhichcanfindlesscostmulticastroutingtree.TheresultsofsimulationandexperimentsconfirmthatDADMalgorithmcanfindthelesscostmulticasttree.Finally,analyzetherelationbetweenthesizeofdegree-constrainedandvalueofmulticasttreecost.(6)Presentadelay-constraineddynamicmulticastroutingalgorithmsuitableforvideoconferencecharacteristic,andadviseaseriesofschemesreducingthedelayoftransmittingallthemediaonvideoconference.(7)FirstproposeimplementingthereliablemulticastroutingtransportprotocolusingBIN,therebyACKimplosionproblemcanbesolved.Theprotocolonlyrequiresfin
简介:AMultimediastreamsdynamicratecontrolalgorithmbasedonFuzzyadaptivePID(MFPID)hasbeenproposedtoimplementmultimediastreams'endsendingrateon-lineself-regulatingandsmoothing,andtotracksystemresourcesintime,sothatitcanavoidsystem'sregulatingoscillationandguaranteesystem'sstability.And,someworkhasbeendonetoanalyzeadaptivesessionmodelofmultimediastreams,toimplementfutureavailablebandwidthestimationofIPnetwork,toachievePIDparameters'on-lineself-tuningbyfuzzycontrolling.SimulationvalidatedthetheoreticalresultsofMFPID.