简介：PolygonalobjectisafundamentaltypeofgeometricdatainvectorGIS.Thekeystepofcleaningtopologicalrelationshipafterdatacollectionofpolygonallayeristobuildpolygonalobjectsfromdigitalarcs.Therawdigitalarcsmayintersectwitheachother.Thealgorithmforbuildingpolygonalobjectsaftertherawarcshavebeensplitatallintersectionsispresented.Thebuild-upofpolygonalobjectsinthispaperisdesignedtobeimplementedbytwosteps.Thefirststepistoextractallthepolygonsneededforbuild-upofpolygonalobjectsfromarcs.Thesecondstepistoorganizepolygonalobjectsfromthesepolygons.Forthefirststep,atracingalgorithmisproposed.Thealgorithmmerelyextractsthepolygonsneededforthebuild-upofpolygonalobjects,whichisasubsetofallthepossiblepolygonsthatcanbeinducedfromthearcs.Forthesecondstep,analgorithmbasedonaspeciallydesignedorderofpolygonsisadvanced.Allthetopologicalrelationshipsamongthepolygonsaresho

简介：Thispaperconsiderstheproblemofplanningthemotionofasearcherinapolygonalregiontoeventually'see'anintruderthatisunpredictableandcapableofmovingarbitrarilyfast.Asearcheriscalledtheboundarysearcherifhecontinuouslymovesonthepolygonboundaryandcanseeonlyalongtheraysoftheflashlightsheholdsatatime.Wepresentnecessaryandsufficientconditionsforann-sidedpolygontobesearchablebyaboundarysearcher.Basedonourcharacterization,theequivalenceoftheabilityofthesearchershavingonlyoneflashlightandtheoneofthesearchershavingfull360°visionissimplyestablished,andmoreover,anoptimalO(n)timeandspacealgorithmfordeterminingthesearchabilityofsimplepolygonsisobtained.WealsogiveanO(nlogn+I)timealgorithmforgeneratingasearchscheduleifitexists,whereI(<3n~2)isthenumberofsearchinstructionsreported.OurresultsimproveuponthepreviouslyknownO(n~2)timeandspacebounds.

简介：Polygonalmodelsarepopularrepresentationsof3Dobjects.Theuseofpolygonalmodelsincomputationalapplicationsoftenrequiresamodeltoproperlybounda3Dsolid.Thatis,thepolygonalmodelneedstobeclosed,manifold,andfreeofself-intersections.Thispapersurveysasizeableliteratureforrepairingmodelsthatdonotsatisfythiscriteria,focusingoncategorizingthembytheirmethodologyandcapability.Wehopetoofferpointerstofurtherreadingsforresearchersandpractitioners,andsuggestionsofpromisingdirectionsforfutureresearchendeavors.

简介：Whenstudyingtheregularpolygonalinclusionin1997,NozakiandTayadiscoverednumericallysomeremarkablepropertiesofEshelbytensor:EshelbytensoratthecenterandtheaveragedEshelbytensorovertheinclusiondomainareequaltothatofacircularinclusionandindependentoftheorientationoftheinclusion.ThenKawashitaandNozakijustifiedthepropertiesmathematically.Inthepresentpaper,someotherpropertiesofaregularpolygonalinclusionarediscovered.WefindthatforanN-foldregularpolygonalinclusionexceptforasquare,thearithmeticmeanofEshelbytensorsatNrotationalsymmetricalpointsintheinclusionisalsoequaltotheEshelbytensorforacircularinclusionandindependentoftheorientationoftheinclusion.Furthermore,intwocorollaries,wepointoutthatEshelbytensoratthecenter,theaveragedEshelbytensorovertheinclusiondomain,andthelineintegralaverageofEshelbytensorsalonganyconcentriccircleoftheinclusionareallidenticalwiththearithmeticmean.

简介：AnovelconstructionalgorithmispresentedtogenerateaconformingVoronoimeshforanyplanarstraightlinegraph(PSLG).Itisalsoextendedtotesselatemultiple-intersectedPSLGs.Allthealgorithmsareguaranteedtoconverge.Examplesaregiventoillustrateitsefficiency.

简介：Weintroducetwoimprovementsinthenumericalschemetosimulatecollisionandslowshearingofirregularparticles.First,weproposeanalternativeapproachbasedonsimplerelationstocomputethefrictionalcontactforces.TheapproachimprovesefficiencyandaccuracyoftheDiscreteElementMethod(DEM)whenmodelingthedynamicsofthegranularpacking.Wedeterminetheproperupperlimitfortheintegrationstepinthestandardnumericalschemeusingawiderangeofmaterialparameters.Tothisend,westudythekineticenergydecayinastresscontrolledtestbetweentwoparticles.Second,weshowthattheusualwayofdefiningthecontactplanebetweentwopolygonalparticlesis,ingeneral,notuniquewhichleadstodiscontinuitiesinthedirectionofthecontactplanewhileparticlesmove.Tosolvethisdrawback,weintroduceanaccuratedefinitionforthecontactplanebasedontheshapeoftheoverlapareabetweentouchingparticles,whichevolvescontinuouslyintime.

简介：这份报纸开发acoupled动力学模型因为线性正式就职马达(秘鲁利玛机场之代号)车辆和一条地铁追踪在系统的动态行为上调查车辆的多角形的车轮的影响。在模型，车辆与自由的35度作为一个多身体系统被建模。一根Timoshenko横梁被用来为被睡眠者分离地支持的栏杆建模。睡眠者作为僵硬身体被建模与他们的垂直，侧面，并且滚动运动正在被考虑。以便模仿沿着课程跑的车辆，一个动人的睡眠者支持模型被介绍由分离睡眠者支持者，睡眠者在被假定以与火车速度一样的经常的速度向后移动模仿刺激。赫兹波接触理论和Shen-Hedrick-Elkins模型被利用分别地处理在车轮和栏杆之间的正常动态力量和正切的力量。以便更好描绘线性metro系统(LMS)，Euler横梁理论基于形式的重叠，方法被用来为秘鲁利玛机场之代号和RP建模。在LIM和RP之间的垂直电的磁性的力量和侧面的恢复力量也被考虑。前者有变化差距的非线性的特征，虽然后者被看作恢复1kN的力量的一个常数。数字分析在系统的动态行为上由于多角形的车轮考虑刺激的效果在不同穿阶段，在哪个使用的数据关于多角形上穿车轮踩直接在地铁地点被测量。

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简介：Numericalcomputationsareperformedforthenaturalconvectionincircularenclosureswithinnerpolygonalcylinders.Thepolygonsurfaceandtheouterenvelopeareatconstantbutdifferenttemperatures.Abody-flttedcoordinatesystemisused.Thecoordinatesystemisgeneratedviasimplealgebraicequations.Thetransformedgoverningequationsarediscretizedonacontrolvolumebasiswithpower-lawfilitedifferencescheme.TheSIMPLE-likealgorithmisusedtodealwiththelinkagebetweenpressureandvelocities.Thenumericalresultsarecomparedwiththeexperimentaldataavailableintheliterature,andtheagreementbetweenthenumericalandexperimentalresultsareverygood.