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295 个结果
  • 简介:ThisarticledescribesalocalerrorestimatorforGlimm'sschemeforhyperbolicsystemsofconservationlawsandusesittoreplacetheusualrandomchoiceinGlimm'sschemebyanoptimalchoice.Asaby-productofthelocalerrorestimator,theprocedureprovidesaglobalerrorestimatorthatisshownnumericallytobeaveryaccurateestimateoftheerrorinL1(R)foralltimes.Althoughthereispartialmathematicalevidencefortheerrorestimatorproposed,atthisstagetheerrorestimatormustbeconsideredad-hoc.Nonetheless,theerrorestimatorissimpletocompute,relativelyinexpensive,withoutadjustableparametersandatleastasaccurateasotherexistingerrorestimators.Numericalexperimentsin1-DforBurgers'equationandforEuler'ssystemareperformedtomeasuretheasymptoticaccuracyoftheresultingschemeandoftheerrorestimator.

  • 标签: 局部误差估计 自适应 作者 版本 双曲守恒律 随机选择
  • 简介:Luby和Rackoff由用一大随机的功能代替每圆功能理想化DES。在这篇论文,作者由用一小随机的功能代替每S盒子理想化山茶,它被称为像山茶的计划。five-roundCamellia-like计划是假散乱,八回合的像山茶的计划为适应对手是超级假散乱的,这然后被证明。进一步,纸考虑Camellia-likescheme的更有效的建设,并且讨论怎么构造假散乱从更少的随机的像山茶的计划工作。

  • 标签: 块密码 随机函数 伪随机性 DES 数据加密标准
  • 简介:Inubiquitouscomputing,datashouldbeabletobeaccessedfromanylocation,andthecorrectnessofdatabecomesvitalduringthecommunication.Supposethatmanyuserssigndifferentmessagesrespectively,beforeforwardingorsendingthesemessages,thentheverifiermustspendalotofcomputingtimetoverifytheirsignatures.Consequently,theaggregatesignatureschemeisaneffectivemethodofimprovingefficiencyinthiskindofsystems,whichprovidestheconveniencefortheverifier.Inthispaper,weproposeanewcertificatelessaggregatesignatureschemewhichisefficientingeneratingasignatureandverification.ThisschemeisprovablysecureundertheextendedcomputationalDiffie-Hellmanassumption.

  • 标签: 签名方案 DIFFIE-HELLMAN假设 聚合 证书 计算时间 可证明安全
  • 简介:隐私是在电子投票的一个重要问题。在电子投票的完整的隐私的概念第一被建议,不是仅仅选民的隐私被担心,而且候选人的。没有任何信任第三方,保存电子选举建筑学的隐私被介绍,为k-out-of-m选举的一种一般技术也基于分布式的ElGamal加密和混合火柴被提供。没有揭示他们的愿望和输的候选人的投票,选民能自己计算结果。而且,获胜者候选人的投票是否多于一半,能直接被验证。这个计划满足投票并且去模式并且完成完整的隐私。正确性和安全也被分析。

  • 标签: 隐私保护 电子投票 候选人 第三方 分布式 获奖者
  • 简介:Vehielesenlistedwitheomputing,sensingandcommunicatingdevicescancreatevehicularnetworks,asubsetofcooperativesystemsinheterogeneousenvironments,aimingatimprovingsafetyandentertainmentintraffic.Invehicularnetworks,avehicle’sidentityisassociatedtoitsowner’sidentityasauniquelinkage.Therefore,itisofimportancetoprotectprivacyofvehiclesfrombeingpossiblytracked.Obviously,theprivacyprotectionmustbescalablebecauseofthehighmobilityandlargepopulationofvehicles.Inthiswork,wetakeanon-trivialsteptowardsprotectingprivacyofvehicles.Asprivacydrawspublicconcerns,wefirstlypresentprivacyimplicationsofoperationalchallengesfromthepublicpolicyperspective.Additionally,weenvisionvehicularnetworksasgeographicallypartitionedsubnetworks(cells).Eachsubnetworkmaintainsalistofpseudonyms.Eachpseudonymincludesthecell’sgeographicidandarandomnumberashostid.Beforestartingcommunication,vehiclesneedtorequestapseudonymondemandfrompseudonymserver.Inordertoimproveutilizationofpseudonyms,weaddressastochasticmodelwithtime-varyingarrivalanddeparturerates.Ourmaincontributionincludes:1)proposingascalableandeffectivealgorithmtoprotectprivacy;2)providinganalyticalresultsofprobability,varianceandexpectednumberofrequestsonpseudonymservers.Theempiricalresultsconfirmtheaccuracyofouranalyticalpredictions.

  • 标签: 隐私保护 车载网络 可扩展性 通信设备 异构环境 合作系统
  • 简介:Theperformanceofmassivemultiple-inputmultiple-output(MIMO)systemislimitedbypilotcontamination.Toreducethepilotcontamination,uplinkanddownlinkprecodingalgorithmsareputforwardbasedoninterferencealignmentcriterion.Intheuplinkreceivingprocessing,thetargetfunctionalignsthepilotcontaminationandtheinterferencesignalstothesamenullspaceandacquiresthemaximalspacedegreeofthedesiredsignals.Theuplinkreceivingprecodingmatrixissolvedonmaximalsignaltointerferenceplusnoiseratio(SINR)criterionconsideringtheimpactofthepilotcontaminationonchannelestimations.Theuplinkreceivingprecodingmatrixisusedasthedownlinktransmittingprecodingmatrix.Exploitingthechannelreciprocity,itisprovedthat,iftheuplinkreceivingprecodingmatrixachievesmaximalSINR,theidenticalprecodingmatrixcanbeusedinthedownlinktransmissionandacquiresmaximalsignaltoleakageplusnoiseratio(SLNR).Simulationsshowthatthespectrumefficiencyoftheproposedalgorithmcanreachabout1.5timeshigherthanthatofpopularmatchedfiltering(MF)precodingalgorithm,andabout1.1timeshigherthanmulti-cellminimummeansquareerror(MMSE)precodingalgorithm.Theperformanceoftheproposedalgorithmcanbeimprovedapproximatelylinearlywiththeincreasingofthenumberofantennas.

  • 标签: MIMO系统 干扰信号 对齐 编码算法 上行链路 编码矩阵
  • 简介:存取控制计划被建议让系统宽信息管理(游泳)在实际应用程序处理属性撤回的问题。把基于的加密(ABE)基于属性,这个计划介绍代理重新加密机制和关键加密钥匙(KEK)树与属性撤回认识到有细密纹理的存取控制。这份报纸根据民用的航空的现状定义属性。与以前建议的一些另外的计划相比,这个计划不仅弄短密文(CT)和私人钥匙的长度而且改进加密和解密的效率。计划能抵抗串通攻击并且在游泳保证数据的安全。

  • 标签: 游泳 存取控制 代理重新加密 属性撤回
  • 简介:Quantumalgorithmsbringgreatchallengestoclassicalpublickeycryptosystems,whichmakescryptosystemsbasedonnon-commutativealgebraicsystemshoptopic.Thebraidgroups,whicharenon-commutative,haveattractedmuchattentionasanewplatformforconstructingquantumattack-resistantcryptosystems.Aringsignatureschemeisproposedbasedonthedifficultyoftherootextractionproblemoverbraidgroups,whichcanresistexistentialforgeryagainsttheadaptivelycho-sen-messageattackundertherandomoraclemodel.

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  • 简介:Thispaperpresentsfuzzy-baseddesignforthecontrolofoverheadcrane.Insteadofanalyzingthecomplexnonlinearcranesystem,theproposedapproachusessimplebuteffectivewaytocontrolthecrane.Therearetwinfuzzycontrollerswhichdealwiththefeedbackinformation,thepositionoftrolleycraneandtheswingangleofload,tosuppresstheswayandacceleratethespeedwhenthecranetransportstheheavyload.Thisapproachsimplifiesthedesigningprocedureofcranecontroller;besides,thetwincontrollermethodreducestherulenumberwhenfulfillingthefuzzysystem.Finally,experimentalresultsthroughthecranemodeldemonstratetheeffectivenessofthescheme.

  • 标签: 高空起重机 控制系统 模糊控制 非线性控制
  • 简介:一个计划为二面洞镜子为纠缠的状态的产生被介绍。在计划,开始处于一个真空状态的每面镜子与一块弱协调的地交往,导致一个光子数字依赖者踢。从洞漏的一个光子的察觉折叠二面镜子到一个纠缠的状态。

  • 标签: 纠结状态 空泡 电子技术 物理研究
  • 简介:在这篇文章,一个Grassmannianprecoding多用户多重输入多重产量(MU-MIMO)为downlink传播的计划被建议。建议MU-MIMO计划将表现安排并且precoding同时在库驻扎,增加获得多用户差异获得和precoding,最大化系统能力。precoding方法与Grassmannianprecoding有关,它扩大点对点的单个用户的Grassmannianprecoding到point-to-multipoint多用户Grassmannianprecoding。它比单身的用户MIMO(SU-MIMO)系统提供进一步重要的系统能力改进并且也超过块diagonalization(BD)在一样的模拟环境下面的算法。

  • 标签: 同波道干扰 MU-MIMO 多用户多输入多输出系统 无线通信
  • 简介:AGeometricRepresentationSchemeSuitableforShapeOptimizationWangXuelinandZhouJiCADCenter,HuazhongUniversityofScienceandTechnolo...

  • 标签: SHAPE optimization NURBS CURVE FINITE ELEMENT
  • 简介:在这份报纸,我们建议三削尖接近的分计划,与三个形状参数,那统一三不同存在三个点接近计划。为到C3连续性和为由使用劳伦多项式方法为参数的某些范围产生张肌产品表面的计划的集中的分曲线C0的一些足够的条件被讨论。曲线和表面设计的系统特别为衣服建模在服装CAD成功地基于我们的计划被开发了。

  • 标签: 细分 逼近 CAD建模 形状参数 充分条件 参数曲面
  • 简介:Takingtheadvantageoftheliftingscheme'scharactersthatcanbuildwavelettransformsfortransformingfromintegertointegerandthequalityofthereconstructingimageisindependentofthetopologywayadoptedbytheboundary,animagefusionalgorithmbasedonliftingschemeisproposed.Thispaperdiscussesthefundamentaltheoryofliftingschemefirstlyandthenaftertakingtransformanalysisaccordingtoakindofimagesthatneedtobeconfused.

  • 标签: 数据压缩 图像压缩 提升方法 图像处理
  • 简介:Aquantitativeschemeisputforwardinourworkofforecastingthestormrainfalloftyphoonsforspecificsites.Usingtheinitialparameters,weathersituationsandphysicalquantitiesaswellasnumericalweatherpredictionproducts,theschemeconstructsmultivariate,objectiveandsimilaritycriteriaforenvironmentalfactorsforthetimebetweenthecurrentandforthcomingmomentwithinthedomainofforecast.Throughdefininganon-linearsimilarityindex,thisworkpresentsacomprehensiveassessmentofthesimilaritybetweenhistoricalsamplesoftyphoonsandthosebeingforecastintermsofcontinuousdynamicstatesunderthemultivariatecriteriainordertoidentifysimilarsamples.Thehistoricalrainfallrecordsofthesimilarsamplesareusedtorunweightedsummarizationofthesimilarityindextodeterminesite-specificandquantitativeforecastsoffuturetyphoonrainfall.Samplesresemblingthetyphoonbeingforecastareselectedbydefininganon-linearsimilarityindexcomposedofmultiplecriteria.Trialtestshavedemonstratedthatthisschemehaspositivepredictionskill.

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  • 简介:MM5,它是PSU/NCAR中央放大非静水力学的有限区域的模型,并且它毗连当模特儿的系统在这篇论文被使用。由使用二假数据吸收的台风的一个最佳的起始的条件策划的作者产生的背景回答的拿的T106分析数据,和某数字模仿试验的行为。No.9608typhoon(葛洛丽亚)的结果证明最佳的起始的地有一些戏剧的改进,例如台风中心,更弱的台风发行量和台风的不完全的内部结构的不精密的位置,它被数据的缺乏在海上引起。一些改进在轨道预报被做了。通过几个比较实验,BDAscheme优化的初始化比GFDL计划和它的台风路经预报更好被发现更合理。

  • 标签: 四维空间同化 BDA图 GFDL图 台风数字模拟 路径预测