学科分类
/ 25
500 个结果
  • 简介:X-rayimagingistheconventionalmethodfordiagnosingtheorthopedicconditionofapatient.ComputerizedTomography(CT)scanningisanotherdiagnosticmethodthatprovidespatient’s3Danatomicalinformation.However,bothmethodshavelimitationswhendiagnosingthewholeleg;X-rayimagingdoesnotprovide3Dinformation,andnormalCTscanningcannotbeperformedwithastandingposture.Obtaining3Ddataregardingthewholeleginastandingpostureisclinicallyimportantbecauseitenables3Danalysisintheweightbearingcondition.Basedontheseclinicalneeds,ahardware-basedbi-planeX-rayimagingsystemhasbeendeveloped;itusestwoorthogonalX-rayimages.However,suchmethodshavenotbeenmadeavailableingeneralclinicsbecauseofthehightcost.Therefore,weproposedawidelyadaptivemethodfor2DX-rayimageand3DCTscandata.Bythismethod,itispossibletothreedimensionallyanalyzethewholeleginstandingposture.TheoptimalpositionthatgeneratesthemostsimilarimageisthecapturedX-rayimage.Thealgorithmverifiesthesimilarityusingtheperformanceoftheproposedmethodbysimulation-basedexperiments.Then,weanalyzedtheinternal-externalrotationangleofthefemurusingrealpatientdata.Approximately10.55degreesofinternalrotationswerefoundrelativetothedefinedanterior-posteriordirection.Inthispaper,wepresentausefulregistrationmethodusingtheconventionalX-rayimageand3DCTscandatatoanalyzethewholelegintheweight-bearingcondition.

  • 标签: 2D-3D REGISTRATION 3D analysis X-RAY CT
  • 简介:Wetackletheproblemofconstructing2DcentroidalVoronoitessellationswithconstraintsthroughanefficientandrobustconstructionofboundedVoronoidiagrams,thepseudo-dualoftheconstrainedDelaunaytriangulation.WeexploitthefactthatthecellsoftheboundedVoronoidiagramcanbeobtainedbyclippingtheordinaryonesagainsttheconstrainedDelaunayedges.Theclippingitselfisefficientlycomputedbyidentifyingforeachconstrainededgethe(connected)setoftriangleswhosedualVoronoiverticesarehiddenbytheconstraint.TheresultingconstructionisamenabletoLloydrelaxationsoastoobtainacentroidaltessellationwithconstraints.

  • 标签: VORONOI图 约束Delaunay三角网 二维 隐藏设置 三角形 约束边
  • 简介:

  • 标签:
  • 简介:The2Dplanegasflowunderheating(withnonentityboundarycondition)hasbeendiscussedbytheanalyticalapproachinthispaper.Theapproximateanalyticalsolutionshavebeenobtainedfortheflowpassingvariouskindsofheatsources.Solutionsdemonstratethethermaldisplacementphenomenaarestronglydependontheheatingintensity.

  • 标签: 热流体流 热位移 解析解
  • 简介:Cavitationisoneofthetroublesomeproblemsinrocketturbopumps,andsincemostofhigh-efficiencyrocketpropellantsarecryogenicfluids,socalled'thermodynamiceffect'becomesmoreevidentthaninwater.Inthepresentstudy.numericalandexperimentalstudyofliquidnitrogencavitationin2DLavalnozzlewascarriedout,sothattheinfluenceofthermodynamiceffectwasexamined.Itwasrevealedthattemperatureandcavitationhavestronginter-relationshipwitheachotherinthermo-sensitivecryogenicfluids.

  • 标签: 计算流体力学 CFD 喷流 两相流 空化 低温
  • 简介:Thenew-typetractionboundaryintegralequationsdevelopedbyHuandwithnohypersingularintegralareappliedtoanalysisof3Dfinitecrackedbodies.Anumericalalgorithmforgeneral3Dproblemsandasemi-analyticaloneforaxisymmetricproblemsarepresented.Someexamplesofthickplatesandcylindricalcolumnsincludingpenny-shapedcrack(s),andrectangularplatesincludinganellipticalcracknormaltothesurfaceareanalyzed.Thecomparisonbetweenpresentresultsandthoseinliteratureshowsthehighaccuracyandeffectivenessofthepresentmethod.

  • 标签: principal integral crack stress INTENSITY factor
  • 简介:氢存储的关键是与轻集体、大表面和富有的吸附地点设计新材料。在综合基于最近的试验性的成功tripyrrylmethane,我们探索了Ti-tripyrrylmethane基于的2D为氢存储使用的多孔的结构密度功能的理论。我们发现了结构是稳定的,并且暴露的Ti地点能与平均绑定绑三个氢分子0.175eV/H的精力在房间温度并且在周围的压力为氢的存储和版本躺在精力窗户的2,。

  • 标签: 多孔结构 储氢 二维 密度泛函理论 平均结合能 释放能量
  • 简介:Solutionstoapiezoelectrichalf-planewithafixedconductorsurfaceelectrodesubjectedtotwogeneralizedsingularities(linedislocationand/orlineforceandfreecharge)arepresented.Coulombforcesactingonthesingularitiesduetotheboundarypolarizationchargesofmediumandtheinductioncharg-esofconductorelectrodeareanalyzedindetail.Theinteractionbetweenthetwosingularitiesisalsoanalyzednumerically.ResultsshowthatCoulombforceswillbecomeimportantasthefreechargeapproachestheboundaryortwosingularitiesmoveclosely.

  • 标签: Green’s FUNCTIONS COULOMB FORCES LINE DISLOCATION
  • 简介:为在一个三维的围住的领域的不可压缩的二进制液体混合物的进化的二个不同模型被考虑。他们由3D组成不可压缩的海军司烧方程,使外部力量遭到到时间依赖者并且结合了一个对流Allen-Cahn或Cahn-Hilliard方程。如此的系统能被看作海军司烧方程的归纳到二阶段的液体。用轨道途径,作者为两个系统证明轨道引起注意的人的存在。

  • 标签: 流体混合物 三维轨迹 吸引子 STOKES方程 二元 不可压缩
  • 简介:PhaseShiftingAndLogicalMoire(PSALM)isakindofcomputerimageprocessingmethodwhichcanbeusedinphasemeasurementandtoobtaintheshape,deformationandstraindistributionofanobject.Thispaperpresentsthestructureandworkingprocedureofa2DphasemeasurementPSALM2Dprogramanditsapplication.Whenanalyzingmoireinterferometricfringes,wecanobtain2Ddistributionofdisplacementandstrain.Whenitisusedinreflectionmoirewecanmeasuretheslopeofaspecimen.SatisfactoryvisualizationandquantitativeresultsaregivenbyPSALM2D.

  • 标签: logical MOIRE phase SHIFTING IMAGE PROCESSING
  • 简介:连贯的多角形的粒子的二维的分离元素模型(DEM)模拟被开发了估计点来源颤动的利益在楔形的hoppers导致流动。使用的particleparticle相互作用模型基于一个多接触原则。没有颤动,学习的第一部分在严肃下面调查了粒子分泌物决定批评的孔尺寸(Bc)就作为粒子形状的功能支撑流动。多角形形状的粒子比圆形的粒子需要一个更大的孔,这被显示出。当粒子顶点的数字增加,Bc减少,这也被显示出当粒子顶点的数字增加。圆形的粒子的增加以一种线性方式支持多角形的流动。学习的第二部分证明那颤动能提高流动,有效地减少Bc。模型表明了震荡器地点(高度)的重要性,与在提高的以前的连续统模型结果,和颤动振幅一致流动。

  • 标签: 动力效应模型 固体 振动 仿真
  • 简介:Commerciallyavailablelatticescontainvariouskindsofmorphologicalimperfectionswhichresultingreatdegradationinlattices’mechanicalproperties,therefore,toobtainimperfectioninsensitivelatticestructureisobviouslyapracticalresearchsubject.Hierarchicalstructurematerialswerefoundtobeaclassofpromisinganti-defectmaterials.Thispaperbuildshierarchicallatticebyaddingsoftadhesiontolattice’scelledgesandnumericalresultsshowthatitsimperfectionsensitivitytomissingbarsisminorcomparedwiththeclassiclattice.Softadhesionwithappropriatepropertiesreinforcecelledge’sbendingstiffnessandthusreducethebendingdeformationinlatticecausedbymissingbarsdefect,whichisconfirmedbystatisticalanalysisofnormalizednodedisplacementsofimperfectlatticesunderhydrostaticcompressionandshearloads.

  • 标签: 敏感性 缺陷 晶格结构 二维 结构材料 力学性质