学科分类
/ 25
500 个结果
  • 简介:

  • 标签:
  • 简介:

  • 标签:
  • 简介:Inthispaper,anewresult,newformulasoftransferfunctionandinputimpedancefor2-Ddissipativereactancenetworkcascadesynthesisisgivenintermsofsimplifiedformulastorealizedoublyterminatedresistively1-Ddissipativereactancenetworks.Thenewresultincludesthemoregeneralcases,e.g.thebothcanbedissipativeoroneisdissipativeandtheanotherisalosslessreactancesubnetworkandsoon.Twocalculationexamplesaregiveninthepapertoillustratetheaboverealizations.Besides,consideringsomeproblemsofthedirectconnectionbetweentwosubnetworks,wealsointroduceone-waylinestodiscussthecascadesynthesisofnonreciprocal2-Ddissipativereactancenetworks.

  • 标签: DISSIPATIVE illustrate simplified CASCADE terminated FORMULAS
  • 简介:在这篇论文,二维的单个Roesser模型(2-DSRM)的双系统的性质和概念被学习。双系统的二个不同概念为2-DSRM被建议。一个人从为打电话给S双的系统的二维的单个一般模型(2-DSGM)定义的两重性被导出;另一个基于2-DSRM被定义在一传统叫感觉T双的系统。2-DSRM是否是免费的跳模式或跳模式,被看那可达到,然后,它能相等地被转变成2-DSRM,T两重性和S两重性为是相等的一种正规形式。这将具有在2-DSRM的柔韧的控制的一些观点应用。关键词2-D系统-单个系统-两重性-可控制性这个工作被中国的国家自然科学基金会部分地支持(号码60474078,60574015,60674014),并且部分地为博士后的研究资金(0601010B)由江苏计划了工程。邹云从西北的大学在数学收到了学士学位,Xian,中国在1983,并且在从科技的南京大学设计的自动控制的硕士和博士学位,南京,中国,1987,和1990分别地。他当前是在科技的南京大学的电力工程的一个教授。他的当前的研究兴趣包括微分代数学的方程系统,二维的系统,单个不安,功率系统的短暂稳定性,和功率市场。邹博士是杂志的一个评论家美国数学社会的数学评论,和一个成员。徐惠玲在2005从科技的南京大学在控制科学和控制工程收到了博士学位。她兴趣的区域包括柔韧的过滤和控制,单个系统,二维的系统和非线性的系统。

  • 标签: 二维系统 奇异系统 对偶性 可控性 ROESSER模型
  • 简介:基于夫妇波浪方程和有限差别的时间域(FDTD)算法,2-Dphotonic水晶couplers的强壮的夫妇特征被计算。理论分析和数字模仿的结果显示在2-Dphotonic水晶coupler的精力不能完全在二波导之间被转移。与弱联合理论的结果相比,我们的结果是更精确的。CLC数字TN252文件代码A由福建省(2001J008)的青春科技革新条款基础支持了

  • 标签: 二维光子晶体 波导连接器 波方程 有限微分时间域
  • 简介:Astochastictwo-dimensionalFornasini-Marchesini'sModelⅡ(2-DFMMⅡ)withmultiplicativenoiseisgiven,andafilteringalgorithmforthismodel,whichisoptimalinthesenseoflinearminimum-variance,isdeveloped.Thestochastic2-DFMMⅡwithmultiplicativenoisecanbereducedtoa1-Dmodel,andtheproposedoptimalfilteringalgorithmforthestochastic2-DFMMⅡwithmultiplicativenoiseisobtainedbyusingthestateestimationtheoryof1-Dsystems.Anexampleisgiventoillustratethevalidityofthisalgorithm.

  • 标签: 海洋工程 二维系统 海洋地震 随机系统 运算法则
  • 简介:Theboundaryelementmethodisusedforthemodalanalysisoffreevibrationof2-Dcompositestructuresinthispaper.Sincetheparticularsolutionmethodisusedtotreatthetermsofbodyforces(inertialforces)intheequationofmotion,onlystaticfundamentalsolutionsareneededinsolvingtheproblem.Foranisotropiccantileverbeam,thenumericalresultsobtainedbyusingtheBEMpresentedinthispaperareingoodagreement,withthoseofusingFEMorotherBEM,butthisBEMcanalsobeusedtoanalyzeproblemsforanisotropicmaterials.Forsimplysupportedcompositelaminatedbeams,thecomparisonsofthenumericalresultsobtainedbythismethodwiththeanalyticalresultsobtainedby1-Dlaminatedbeamtheoryindicatethatiftheratiooflength/thicknessisgreaterthan20,theresultsofthetwomethodsareingoodagreement,butiftheratiooflength/thicknessislessthan20,bigerrorswilloccurfor1-Dlaminatedbeamtheory.

  • 标签: COMPOSITE structure BOUNDARY ELEMENT METHOD particular
  • 简介:用photonic晶体(PC),轻射出的二极管(LEDs)的抽取效率能被photonic乐队差距(PBG)和栅栏衍射的效果极大地提高。二个理论方法也被讨论。同时,我们证明LEDs能由作为衍射栅栏采用photonic水晶完成高抽取效率。有圆柱的单位房间的方形的格子的PC被制作在轧了带的基于陷阱的蓝色的层。我们在场PC-LED的抽取效率的理论讨论,它依靠有效中等理论和传播矩阵方法调查格子常数的效果。当格子常数是270nm时,结果证明高效LEDs的抽取效率能完成61.8%。

  • 标签: 提取效率 光子晶体 LED 蓝色发光二极管 有效介质理论 光栅衍射
  • 简介:AfiniteelementmethodforthesolutionofOseenequationinexteriordomainisproposed.Inthismethod,acircularartificialboundaryisintroducedtomakethecomputationaldomainfinite.Then,theexactrelationbetweenthenormalstressandtheprescribedvelocityfieldontheartificialboundarycanbeobtainedanalytically.Thisrelationcanserveasanboundaryconditionfortheboundaryvalueproblemdefinedonthefinitedomainboundedbytheartificialboundary.Numericalexperimentispresentedtodemonstratetheperformanceofthemethod.

  • 标签: Artificial BOUNDARY EXTERIOR DOMAIN Oseen equation.
  • 简介:弄平的粒子水动力学(SPH)是一个Lagrangian无网孔的粒子方法。然而,它内核近似的低精确性当粒子是分布式的时在边界附近混乱或定位是以它的宽应用程序的方法站的一个障碍。采用泰勒系列扩大方法并且解决不可分的方程矩阵,第二个顺序核近似方法能被获得,也就是K2_SPH,它在这份报纸被讨论。这个方法类似于有限粒子方法。与核近似的改进,一些数字技术应该为边界的不同类型被采用,例如一条免费表面边界和稳固的边界,它是为水波浪模拟的K2_SPH的二种关键数字技术。这份报纸给一些涉及由使用K2_SPH承受波浪和sloshing坦克问题的二维的水波浪模拟的数字结果。从模拟结果的比较,K2_SPH方法比标准SPH更可靠。

  • 标签: SPH方法 模拟 水波 应用 泰勒级数展开 粒子方法
  • 简介:AnewcompactopticalFanofiltersuitableforbiologicalsensingisproposed,whichpatternsphotoncrystalinsinglecrystallinesiliconnanomembranes(SiNMs)andtransferringontotransparentglasssubstrates.Theeffectsofairholesizeandsiliconthicknessonthetransmissioncharacteristicsofnewfilterarenumericallyinvestigatedbyusingthree-dimensionalfinite-differencetime-domain(FDTD)technique,thespectralresponseisalsostudiedbyback-fillingbioliquid.Theresultsshowthatthedipwavelengthwillshifttowardlongerwavelengthbyeitherreducingairholeradiusorfillingbio-liquid.Thenumberofdipswillincreasewiththeincreaseofsiliconthickness.Thesizeofproposedfiltercanbelessthan1mm2.

  • 标签: 二维光子晶体 生物传感 玻璃基板 过滤器 三维有限差分 光学遥感器
  • 简介:Whenabodynavigateswithcavityinshallowwater,bothflexiblefreesurfaceandrigidbottomwallwillproducegreatinfluencesonthecavityshapeandhydrodynamicperformances,andfurtheraffectthemotionattitudeandstabilityofthebody.Inthepresentwork,characteristicsofthenaturalcavitatingflowarounda2-Dsymmetricalwedgeinshallowwaterwereinvestigatedandtheinfluencesoftwotypeboundariesontheflowpatternwereanalyzed.TheVolumeOfFluid(VOF)multiphaseflowmethodwhichissuitableforfreesurfaceproblemswasutilized,coupledwithanaturalcavitationmodeltodealwiththemass-transferprocessbetweenliquidandvaporphases.Withintherangeofthecavitationnumberforcomputation(0.07-1.81),thecavityconfigurationswouldbedividedintothreetypes,viz.,stabletype,transitiontypeandwake-vortextype.Inthisarticle,theshapesofthefreesurfaceandthecavitysurface,andthehydrodynamicperformanceofthewedgewerediscussedundertheconditionsofrelativelysmallcavitationnumber(<0.256).Thepresentnumericalcavitylengthsgenerallyaccordwithexperimentaldata.Whenthecavitationnumberwasdecreased,thecavitywasfoundtobecomelongerandthicker,andthescopeofthedeformationofthefreesurfacealsograduallyextends.Thefreesurfaceandtheuppercavitysurfacecorrespondfairlytotheirshapes.However,thelowersideofthecavitysurfacewasratherleveledduetotheinfluenceofwallboundary.Theliftanddragcoefficientsofthis2-Dwedgebasicallykeeplinearrelationswiththenaturalcavitationnumbersmallerthan0.157,whereasdirectproportionfordragandinverseproportionforlift.

  • 标签: 水动力性能 自然科学 楔形 浅水 自由表面 流量
  • 简介:Videoobjectextractionisakeytechnologyincontent-basedvideocoding.AnovelvideoobjectextractingalgorithmbytwoDimensional(2-D)mesh-basedmotionanalysisisproposedinthispaper.Firstly,a2-Dmeshfittingtheoriginalframeimageisobtainedviafeaturedetectionalgorithm.Then,higherorderstatisticsmotionanalysisisappliedonthe2-Dmeshrepresentationtogetaninitialmotiondetectionmask.Afterpost-processing,thefinalsegmentingmaskisquicklyobtained.Andhencethevideoobjectiseffectivelyextracted.Experimentalresultsshowthattheproposedalgorithmcombinesthemeritsofmesh-basedsegmentingalgorithmsandpixel-basedsegmentingalgorithms,andherebyachievessatisfactorysubjectiveandobjectiveperformancewhiledramaticallyincreasingthesegmentingspeed.

  • 标签: 视频 对象分析 2-D 网孔 统计学
  • 简介:Inthispaper,ahorizontal2-Dnumericalmodelhasbeendevelopedtosimulateflowprocessesindikeburst.Thefinitedifferencemethodisusedincomputation.Themodelemploys2-Dflowequationsandcansimulatecomplexflowswhensupercriticalflowandsub-criticalflowexistsimultaneouslysuchashydraulicjumps.Severalsimulatedresultsareworkedouttodemonstratetheapplicabilityofthenumericalmodel,suchasfloodpropagationonadrybedofacomplexterrain.

  • 标签: NUMERICAL scheme Flood Complex terrain Adjoint method
  • 简介:TheproblemsofcharacteristicpolynomialassignmentinFomasini-Marchesini(F-M)modelⅡof2-Dsystemsareinvestigated.Thecorrespondingclosed-loopsystemsdescribedbyF-MmodelIIareobtainedviathestatefeedback.Usingthealgebraicgeometrymethod,thecharacteristicpolynomialassignmentinthedosed-loopsystemsisdiscussed.Intermsofthetheoryofalgebraicgeometry,theproblemofcharacteristicpolynomialassignmentistransferredtotheonewhetherarationalmappingisonto.SufficientconditionsforalmostarbitraryassignmentcoefficientsofcharacteristicpolynomialinF-MmodelⅡof2-Dsystemsviastatefeedbackarederived,andtheyareavailableformulti-inputcases.Italsohasbeenshownthatthismethodcanbeappliedtoassignthecharacteristicpolynomialwithoutputfeedback.Thesufficientconditionsforalmostarbitraryassignmentcoefficientsofcharacteristicpolynomialofmulti-input2-DsystemsdescribedbyF-MmodelⅡwithoutputfeedbackareestablished.

  • 标签: F-M模型 特征多项式 代数几何 二维线性系统
  • 简介:双树的复杂小浪变换是在信号并且图象处理的一个有用工具。在这份报纸,我们建议双树的复杂小浪变换(?WT)为图象inpainting的基于的算法问题。我们的途径基于蔡,禅宗,沈和Shens基于framelet的算法。复杂小浪变换在移动不变性,directionality和抗混叠的意义超过标准真实小浪变换。数字结果说明我们的算法的好表演。

  • 标签: 二元树复小波变换 图像修复 平移不变性 图像处理 数值结果 ING