简介:<正>裴秀(公元224~271年)字秀彦,河东闻喜(令山西闻喜县)人,魏国时曾随司马昭行军作战,因参赞军机有功升任尚书,后任尚书仆射。公元265年,司马昭之子司马炎夺取曹魏政权建立西晋王朝,封裴秀为司空(即宰相),兼任地官,掌管国家户籍、土地和交通,由于工作关系,经常要使用和查阅各种地图资料。“制图六体”正是他在亲自实践的基础上,批判继承前人制图经验而创造性地总结出来的地图绘制理论,他奠定了我国中古时期制图的理论基础,推动了地图制图学的发展,在世界制图学史上有着划时代的意义。他明确地写下成文的制图规格,而且在他以后,直到利玛窦的世界地图传入中国以前,中国的地图在内容、形式上虽多变化,在制图法的本质上没有很多新的发展,它始终是我国绘制地图的重要方法。裴秀这一时期的地图,是中国地图史的中坚,迫寻他地图制作的渊源和业迹,基本可以看出明代以前我国制图的发展过程和地图的主要源流。一、裴秀以前的地图地图是人类表达地理景观、描述地物空间位置的一种手段,它的实用价值有时是文字效果无法比拟的。因此,华夏初民在后来的与自然作斗争的过程中,逐渐发现及学会把自己地理活动的范围用符号或图形表示出来,这便成了古典地图。
简介:Thispaperproposestheprincipleofcomprehensiveknowledgediscovery.Unlikemostofthecurrentknowledgediscoverymethods,thecomprehensiveknowledgediscoveryconsidersboththespatialrelationsandattributesofspatialentitiesorobjects.Weintroducethetheoryofspatialknowledgeexpressionsystemandsomeconceptsincludingcomprehensiveknowledgediscoveryandspatialunioninformationtable(SUIT).Intheory,SUITrecordsallinformationcontainedinthestudiedobjects,butinreality,becauseofthecomplexityandvarietiesofspatialrelations,onlythosefactorsofinteresttousareselected.Inordertofindoutthecomprehensiveknowledgefromspatialdatabases,anefficientcomprehensiveknowledgediscoveryalgorithmcalledrecycledalgorithm(RAR)issuggested.
简介:Inthispaperthedevelopmentofthetechnologyofthelaserscanningissummarized.Theprinciplesoflaserrangescanningareintroduced.Basedonthelaserscanningtechnologyandmethods,whichareinvestigatedbytheauthorstosurveydepositvolume,asurveyingsystemisdevelopedandapracticalapplicationisperformed.Itisshownthatthelaser-scanningtechnologyhasobviousadvantagessuchasmeasurementprecision,automationandvisualizationofobserveddataincomparisonwiththetraditionalmethods.Asaresult,laborintensityisrelievedobviouslyandworkefficiencyispromoted.
简介:TwomethodsforsmoothingpseudorangeobservablebyCarrierandDopplerarediscussed.ThentheprocedurebasedontheRINEXobservationfilesistestedusingtheAshtechZ-XII3TgeodeticreceiversdrivenbyastableexternalfrequencyatUNSO.Thispaperproposestoadaptthisprocedureforthelinksbetweengeodeticreceivers,inordertotakeadvantageofthePcodesavailableonL1andL2.Thisnewprocedureusesthe30-secondRINEXobservationsfiles,thestandardoftheInternationalGPSService(IGS),andprocessestheionosphere-freecombinationofthecodesP1andP2;thesatellitepositionsarededucedfromtheIGSrapidorbits,availableaftertwodays.
简介:ThispaperpresentsamethodforthecomputationoftheStokesfor-mulausingtheFastHartleyTransform(FHT)techniques.Thealgorithmismostsuitableforthecomputationofrealsequencetransform,whiletheFastFourierTransform(FFT)techniquesaremoresuitableforthecomputatonofcomplexse-quencetransform.Amethodofsphericalcoordinatetransformationispresentedinthispaper.Bythismethodtheerrors,whichareduetotheapproximatetermintheconvolutionofStokesformula,canbeeffectivelyeliminated.Somenumericaltestsaregiven.ByacomparisonwithbothFFTtechniquesandnumericalintegra-tionmethod,theresultsshowthattheresultingvaluesofgeoidalundulationsbyFHTtechniquesarealmostthesameasbyFFTtechniques,andthecomputation-alspeedofFHTtechniquesisabouttwotimesfasterthanthatofFFTtechniques.
简介:在靠近范围的摄影测量学,3D信息获得基于图象匹配。代码标记的应用程序帮助改进自动匹配和匹配的精确性的水平。这份报纸调查惯性椭圆算法的应用程序编码标记匹配。我们能与某个边界计算一个目标的惯性椭圆。首先,方法被用于一个单个代码标记;角度并且可伸缩是有效的。然后,纸介绍多编码由惯性椭圆匹配方法的标记。旋转和同形异义图象的可伸缩的变化能被惯性椭圆算法计算。这些参数能被用于在任意的态度匹配靠近范围的摄影测量学的代码标记。
简介:Thispaperproposesanewmethodbasedonprincipalcomponentanalysistofindthedirectionofanobjectinanypose.Experimentsshowthatthismethodisfast,canbeappliedtoobjectswithanypixeldistributionandkeeptheoriginalpropertiesofobjectsinvariant.ItisanewapplicationofPCAinimageanalysis.
简介:Amonitoringschememustbesodesignedthatseveralpossiblemod-elscanbeefficientlyseparatedinthestageofanalysisofdeformationmeasure-ments.BasedontheconceptofseparabilitydevelopedbyChenandChrzanowski,amethodologyforthedesignofmonitoringschemeshasbeendevelopedbytheau-thors.Inthemethodacomputersimulationtechniqueisemployed,intowhichsomeruleshavebeenelaboratedallowingminimalhumanintervention.Inthispa-perthecriterionisfirstpresentedandthedesigntechniqueusingthesteponeup-datingprocedureisdiscussed.Finally,designofasimulatedmonitoringnetworkismadeasademonstratingexample.
简介:AtpresentE-commercesystemtendstobecomemorecomplex,andtraditionalsystemdesigningmethodscannotfufiltheneedofE-commercesystem,thusrequiringaneffectivemethodassolution.Withthisconcern,thispaperintroducessomeconceptsofcomponenttechnology,thenbringsforwardthenewconnotationandbasicfeaturesofcomponenttechnologythroughtheanalysisofitstechnologicalcharacter.ThispaperfinallydiscussestheapplicationofcomponenttechnologytoE-commercesystem.
简介:Afewresearchesadoptvirtualrealityinlandslide.Soitissignificanttocombinethephysics-baseddeformablemethodwiththeprocesssimulationofaslidinglandslide,thiswaythedynamicprocessofagoinglandslidecanbesimulated.Theanalysisofthedynamiclawoflandslideprovidesafoundationtoforecastandmakeitrealiabletoforetelldisasters.AfterrecountingtheconditionofVRandlandslidingbodysimulation,thispaperputsforwardsimulatinglandslidebythephysics-baseddeformablemethod.Themethoddivideslandslidingintodeformablebodyandrigidone.ThedeformationofdeformablebodycanbecomputebyDDAandFEM,andDDAfitsthegreatdeformationandFEMisgoodforthetinydeformation.Thispapershowsitisfeasibletosimulatethelandslideanimationbythismethod.
简介:ThispaperdescribestheuseoftheArc/InfoandArcViewGIStoolstoestimatesoilerosionwithUniversalSoilLossEquation(USLE).Calculationsarebedonebyusingcapabilitiesavailable.Thisstudystartwithadigitalelevationmodel(DEM)ofShaanxi,whichwascreatedbydigitizingcontourandspotheightsfromthetopographicmapon1∶250000scaleandgridthemesfortheUSLEKandCfactors.ItisnoteworthythatUSLEKcanbeobtainedbyaddingtheKfactorasanattributetoasoiltheme'stable.TheCcanbeobtainedfromtablesorusingtheinformationaboutlanduseandmanagementgivenbyUSLEprogram.AlandusethemecanbeusedtoaddtheCfactorsasanattributefield.ThepurposeofthisstudyistoestablishspatialinformationofsoilerosionusingUSLEandGISanddiscusstheanalysisofthesoilerosionandslopefailuresinGISandformulatethepossibleframework.
简介:Tomeettheauthorizationadministrationrequirementsinadistributedcomputernetworkenvironment,thispaperextendstherole-basedaccesscontrolmodelwithmultipleapplicationdimensionsandestablishesanewaccesscontrolmodelED-RBAC(ExtendedRoleBasedAccessControlModel)forthedistributedenvironment.Weproposeanextendablehierarchicalauthorizationassignmentframeworkanddesigneffectiverole-registering,role-applyingandrole-assigningprotocolwithsymmetricandasymmetriccryptographicsystems.Themodelcanbeusedtosimplifyauthorizationadministrationinadistributedenvironmentwithmultipleapplications.
简介:Accesscontrolinmulti-domainenvironmentsisoneoftheimportantquestionsofbuildingcoalitionbetweendomains.OnthebasisofRBACaccesscontrolmodel,theconceptsofroledelegationandrolemappingareproposed,whichsupportthethird-partyauthorization.Then,adistributedRBACmodelispresented.Finallytheimplementationissuesarediscussed.
简介:这研究的主要目的是在伊拉克的南部的部分的一个代表性的区域在最后20年期间加亮环境变化指示物(Basrah省作为一个盒子被拿)可伸缩理解用印射的1:250000导致了普遍环境降级现象的主要原因。遥感和GIS软件被用来分类Landsat在1990的TM和在进五的2003形象的LandsatETM+打使用和陆地盖子(LULC)班:植被土地,沙陆地,城市的区域,闲置的陆地,和水身体。监督分类和规范的差别植被索引(NDVI),规范的差别逐渐增加索引(NDBI),规范的差别水索引(NDWI),规范的差别咸度索引(NDSI),并且表层土谷物尺寸索引(GSI)在这研究被采用并且分别地过去常检索它的班边界。结果在植物的盖子(514.9km2)和沙沙丘累积(438.6km2)的增加显示出清楚的恶化,为10.1,和10.6%的财务,分别地全部的学习区域。另外,在水身体区域的减少被检测(228.9km2)。沙区域累积在全部的学习区域增加了,与年度增加扩大率(33.7km2???????????吗??
简介:ThebasicprincipleofintervalarithmeticandthebasicalgorithmoftheintervalNewtonmethodsareintroduced.Theprototypealgorithmcannotfindanyzeroinanintervalthathaszerosometimes,thatis,itisinstable.Sotheprototyperelaxationprocedureisimprovedinthispaper.Additionally,animmediatetestoftheexistenceofasolutionfollowingbranch-and-boundisproposed,whichavoidsunwantedcomputationsinthoseintervalsthathavenosolution.ThenumericalresultsdemonstratthattheimprovedintervalNewtonmethodissuperiortoprototypealgorithmintermsofsolutionquality,stabilityandconvergentspeed.
简介:DetectionofaperiodicsignalhiddeninnoiseisthegoalofSuperconductingGravimeter(SG)dataanalysis.Duetospikes,gaps,datumshrifts(offsets)andotherdisturbances,thetraditionalFFTmethodshowsinherentlimitations.Instead,theleastsquaresspectralanalysis(LSSA)hasshoweditselfmoresuitablethanFourieranalysisofgappy,unequallyspacedandunequallyweighteddataseriesinavarietyofapplicationsingeodesyandgeophysics.ThispaperreviewstheprincipleofLSSAandgivesapossiblestrategyfortheanalysisoftimeseriesobtainedfromtheCanadianSuperconductingGravimeterInstallation(CGSI),withgaps,offsets,unequalsamplingdecimationofthedataandunequallyweighteddatapoints.