简介:Farr-Gao算法是为减少的Gr的一个最先进的算法?bner有限的点的消失的理想基于,它作为一个内建的命令在枫树被实现了。这份报纸为它论述二维的改进那为计算减少的Gr采用预处理策略?与给定的点集合的塔子集联系的bner底。试验性的结果证明preprocessedFarr-Gao算法比古典的更有效。
简介:Thegas-kinetictheorybasedfluxsplittingmethodhasbeensuccessfullyproposedforsolvingone-andtwo-dimensionalidealmagnetohydrodynamicsbyXuetal.[J.Comput.Phys.,1999;2000],respectively.Thispaperextendsthekineticmethodtosolvethree-dimensionalidealmagnetohydrodynamicsequations,whereanadaptiveparameterηisusedtocontrolthenumericaldissipationinthefluxsplittingmethod.SeveralnumericalexamplesaregiventodemonstratethattheproposedmethodcanachievehighnumericalaccuracyandresolvestrongdiscontinuouswavesinthreedimensionalidealMHDproblems.
简介:Anewclassofmultilength,constant-weightandtwo-dimensionalmultiwavelengthopticalorthogonalcode(2DMWOOCs)withlargecapacityandgoodcorrelationpropertiesisconstructedbasedonmultilengthone-dimensional(1D)OOCs.TheperformanceofthesenewMWOOCsinanOCDMAnetworkwithdouble-servicesisanalyzed.Theresultshowsthatmediawiththeshortercodewordperformsmuchbetterthanthemediawithlongercodeword,andOCDMAsystemwiththesenewmultilengthMWOOCsperformswell.ThesefeaturesallowmultimediatransmissionoflargecapacityinOCDMAsystem.
简介:Theoff-planepropagationofelectromagnetic(EM)wavesinatwo-dimensional(2D)graphitephotoniccrystalstructurewasstudiedusingtransfermatrixmethod.Transmissionspectracalculationsindicatethatsucha2Dstructurehasacommonbandgapfrom0.202to0.2035c/aforbothHandEpolarizationsandforalloff-planeanglesform0°upto90°.Thepresenceofsuchanabsolutebandgapimpliesthat2Dgraphitephotoniccrystal,whichismucheasierandmorefeasibletofabricate,canexhibitsomepropertiesofathree-dimensional(3D)photoniccrystal.
简介:Thedynamicstressintensityfactorofathree-dimensionalellipticcrackunderimpactloadingisdeterminedwiththefiniteelementmethod.Thecomputationresultscantakeintoaccounttheinfluenceoftimeandtheratioofthewavespeedsonthestressintensityfactor.Thepresentmethodissuitablenotonlyforthree-dimensionaldynamiccrack,butalsoforthree-dimensionaldynamiccontact.
简介:Theobjectiveofthisstudyistocharacterizethethree-dimensionalfluidflowinthevesselcontainingoneceramiccandlefilter.Thethree-dimensionalgoverningequationsareformulatedinthisstudyandtheturbulentκ-εmodelisadoptedforthenumericalcomputation.Itisfoundthattheviscousforceisdominantintheporousregionwithcomparedtoinertiaforce.Pressuedecreaseslinearlywhentheflowpassingthroughtheporousmedium.Whenthefacevelocityis0.03m/s,thepressuredropisabout350Pa.Ithasalsobeenfoundthatthefluidwiththespiralmotiontobesunkintothefilterinthevessel.
简介:线加热过程作为许多因素是很复杂的现象影响剩余变丑的数量。线为剩余变丑的预言加热的数字热、机械的分析是耗时的。在现在的工作,维的分析被介绍了在加热过程的线期间获得在输入参数和产生剩余变丑之间的一种新关系。为6公里,8公里,10公里和12公里的温度分发和剩余变丑厚钢盘子数字地被估计并且与试验性、出版的结果相比。通过一个验证FE模型产生的广泛的数据被用来由多重回归分析发现在输入参数和产生剩余变丑之间的合作关系。从变丑方程获得的结果在在100的顺序在计算时间与落下FE分析与那些作比较很好的这个工作发展了(为FE分析要求的计算时间在到9000秒的7200秒附近并且时间在哪儿为得到剩余要求了由发达方程的变丑仅仅是60~90秒)。关键词维的分析-3-D有限元素分析-elasto塑料的分析-剩余变丑-多重回归分析-氧乙决的煤气的火焰PankajBiswas在1979出生了。他是IITKharagpur的一个研究伙伴,OE&NA的系。他的当前的研究兴趣包括焊接并且装运生产,衬里加热、结构的分析,等等。NisithRanjanMandal在1954出生了。他是IITKharagpur的一个教授,OE&NA的系。他的当前的研究兴趣包括轮船生产,轮船设计,加热的线,大使硬的结构的焊接失真和焊接技术,等等。OmPrakashSha出生了1958。他是IITKharagpur的一个教授,OE&NA的系。他的当前的研究兴趣包括海洋的设计和生产,加热的线,CAD/凸轮,等等。
简介:Thecurrentstructure-preservingtheory,includingthesymplecticmethodandthemultisymplecticmethod,paysmostattentionontheconservativepropertiesofthecontinuoussystemsbecausethattheconservativepropertiesoftheconservativesystemscanbeformulatedinthemathematicalform.But,thenonconservativecharacteristicsarethenatureofthesystemsexistinginengineering.Inthisletter,thestructure-preservingapproachfortheinfinitedimensionalnonconservativesystemsisproposedbasedonthegeneralizedmulti-symplecticmethodtobroadentheapplicationfieldsofthecurrentstructure-preservingidea.Inthenumericalexamples,twononconservativefactors,includingthestrongexcitationonthestringandtheimpactonthecantilever,areconsideredrespectively.Thevibrationsofthestringandthecantileverareinvestigatedbythestructure-preservingapproachandthegoodlong-timenumericalbehaviorsaswellasthehighnumericalprecisionofwhichareillustratedbythenumericalresultspresented.
简介:四维的变化数据吸收(4DVar)是最有希望的方法之一为数字天气预言(NWP)提供最佳的分析。在世界上的五个国家NWP中心成功地在他们的全球NWP使用了4DVar方法,由于增长方法和伴随技术。然而,4DVar的应用程序被在许多NWP中心和研究院可得到的计算机资源仍然限制。因此,进一步减少4DVar的计算费用是必要的。这里,实现4DVar的一条节俭的途径被建议,用dimensionreduced设计(DRP)的技术,它被称为建议途径基于尺寸减小使用的鈥淒RP-4DVar.鈥?历史的样品到的一个整体定义subspace。它直接由恰当的观察在减少的空间获得一个最佳的答案,历史的时间系列由模型产生了到形成一致预报状态,因此不要求正切的伴随的实现线性近似。在吸收mesoscale观察的不同类型上评估DRP-4DVar的性能,一些观察系统模拟实验用MM5被进行,比较用一个6小时的吸收窗口在基于伴随的4DVar和DRP-4DVar之间被做。关键词4DVar-伴随-尺寸减小-历史的样品-观察系统模拟实验
简介:AlthoughHamilton'squaternionhasbeenintroducedsuccessfullyinestimatingfrequenciesoftwodimensionalharmonics,itwasdifficulttouseittoestimatefrequenciesoftwodimensionalharmonicsinadditivenoisebecausethemultiplicativerulesofHamilton'squaternionwerenotcommutative.Inthispaper,wepresentedanewideatosolvethisproblemandappliedittoarraysignalprocessing.First,wepresentedanotherdefinitionofoperationrulesofquaternion,whosemultiplicativeruleswerecommutative.Second,weappliedthisdefinitiontoconstructcorrelationmatrixofhypercomplexsignalmodelbasedonquaternionsoastorestrainadditivenoise.Finally,wegottheisomorphiccomplexmatrixofcorrelationmatrixofhypercomplexsignalmodeltoestimatefrequencies.Somesimulationsillustratedournewidea.
简介:Usingtheextensionhomogeneousbalancemethod,wehaveobtainedsomenewspecialtypesofsolitonsolutionsofthe(2+1)-dimensionalKdVequation.Startingfromthehomogeneousbalancemethod,onecanobtainanonlineartransformationtosimple(2+1)-dimensionalKdVequationintoalinearpartialdifferentialequationandtwobilinearpartialdifferentialequations.Usually,onecanobtainonlyakindofsoliton-likesolutions.Inthisletter,wefindfurthersomespecialtypesofthemultisolitonsolutionsfromthelinearandbilinearpartialdifferentialequations.``