简介:SimilarityforspatialdirectionsplaysanimportantroleinGIS.Inthispaper,theconventionalapproachesareanalyzed.Basedonrasterdataarealobjects,theauthorsproposetwonewmethodsformeasuringsimilarityamongspatialdirections.Oneistomeasurethesimilarityamongspatialdirectionsbasedonthefeaturesofrasterdataandthechangesofdistancesbetweenspatialobjects,theotheristomeasurethesimilarityamongspatialdirectionsaccordingtothevariationofeachrastercellcentroidangle.Thetwomethodsovercomethecomplexityofmeasuringsimilarityamongspatialdirectionswithdirectionmatrixmodelandsolvethelimitationofsmallchangesindirection.Thetwomethodsaresimpleandhavebroaderapplicability.
简介:因为为从空间数据库查询数据的SQL是无效的,询问逐渐地基于自然或视觉的语言成为一个吸引人的研究领域。然而,怎么定义并且表示与空间数据有关的自然语言仍然是巨大的问题。因为存在,方向关系的模型不能由一些普通概念的使用描述。Firstof所有,详细方向关系被建议描述与空间目标的内部有关的方向例如“一个区域的一条区域','东方边界的东方部分”,并且那么on.Secondly,由与外面的方向关系和to-pologicalrelations集成详细方向,几NLSR被定义,例如“一条道路越过一个湖的东方部分去”,“一条河沿着一个省的东方边界去,等等。最后,基于NLSR上述,一种自然空间质问语言(NSQL)被形成从空间数据库检索数据。
简介: IllustrationAllthedatainthiscatalogarechosenfromthe"PreliminarySeismologicalReportofChineseSeismicStations"(Itsabbreviationis"MonthlyReport").ThecatalogincludestheeventsofM≥4.7inandnearChinaandM≥6allovertheworld.The"MonthlyReport"ismonthlycompiledbvtheNinthSectionofInstituteofGeophysics,CSB.……
简介: Illustration Allthedatainthiscatalogarechosenfromthe"PreliminarySeismologicalReportofChineseSeismicStations"(Itsabbreviationis"MonthlyReport").……
简介:IllustrationAllthedatainthiscatalogarechosenfromthe(PreliminarySeismologicalReportofChineseSeismicStations((Itsabbreviationis(MonthlyReport().ThecatalogincludestheeventsofM(4.7inandnearChinaandM(6allovertheworld.The(MonthlyReport(ismonthlycompiledbytheNinthSectionofInstituteofGeophysics,CSB.Theorigintimesofearthquakesinthecatalogadoptcoordinateduniversaltime(UTC)inaccordancewithinternationalconvention.Thelocationofeveryepicenterisexpressedbyitslatitudeandlongitude,atthesametimebythecorrespondinggeographicalregionproposedbyFlinnandEngdahl.Theregionalnamesareonlyforreferencesanddonotimplyanypoliticalsignificance.Thenumberofstationsusedandstandarddeviationarealsogiveninordertoillustratetheprecisionoflocation.
简介:StrongearthquakeactivityalovertheworldandstrongmoderateearthquakeactivitywithinandnearChina(April,1997~May,1997)PEISHANCHEN...
简介: Illustration Allthedatainthiscatalogarechosenfromthe″PreliminarySeismologicalReportofChi-neseSeismicStations″(Itsabbreviationis″MonthlyReport″).ThecatalogincludestheeventsofM≥4.7inandnearChinaandM≥6allovertheworld.The″MonthlyReport″ismonthlycompiledbytheNinthSectionofInstituteofGeophysics,CSB. ……
简介:IlustrationAlthedatainthiscataloguearechosenfromthe″PreliminarySeismologicalReportofChineseSeismicStations″(It′sabbreviation...
简介:StrongearthquakeactivityalovertheworldandstrongmoderateearthquakeactivitywithinandnearChina(June,1996~August,1996)PEISHANCH...
简介:
简介: