An+efficient+spatio-temporal+data+structure+for+multi+version+management+of+engineering+drawings

第l6卷第5期2004年l0月重庆邮电学院学报Vo1．16No．5JournalofChongqingUniversityofPostsandTelecommunicationsOct．2004ArticleID：1004—5694(2004)05-0064—07Anefficientspatio-temporaldatastructureformultiversionmanagementofengineeringdrawings’DEKIHARAHiroyuki，NAKAMURAYasuaki。(1．HiroshimaInternationalUniversity，DepartmentofInformationTechnology。5-l—l。Hiro—koshinkai，Kure，737—0012，Japan；2．HiroshimaCityUniversity，DepartmentofComputerandMediaTechnologies，3-4-1，Ozuka—higashi，Asa—minami-ku，Hiroshima，731—3194，Japan)Abstract：Intheengineeringdatabasesystem，multipleversionsoffldesignincludingengineeringdrawingsshouldbemanagedefficiently．Thepaperproposesanefficientspatialdatastructure，thatisanexpansionoftheR—treeandHR—tree。forversionmanagementofengineeringdrawings．AnovelmechanismtomanagethedifferencebetweendrawingssntroducedtotheHR—treetoeliminateredundantduplicationsandtoreducetheamountofstoragerequiredforthedatastructure．DatamanagementmechanismandstructuralpropertiesofourdatastructurecalledtheMVR十一treearedescribed．Keywords：spatialdatasystem；MVR一treeCLCnumbet：P208；TP391．411Intr0ducti0nstructure；multi—versionmanagement；computeraideddesignDocumentcode：AAcomputeraideddesignsystem(CAD)isthecollectionofsoftwareforcreatingorsynthesizingfldesign，analyzingitfordesigncorrectness，managingthestorageandorganizationofthedesigndata，andmanagingtheprocessofdesignflow．Theengineeringdesigndatausuallyconsistofflsetofdocumentsanddrawingsordiagrams．AdesigndatabasesysteminCADdealswiththestorageandretrievalofdesigndataanditsconsistentupdate．Whentheupdateprocesscreatesflnewversionofdesignfromanoldversion，theoldversionaswellasthenewonemustbekeptinthedatabasebecausetheymaybereferencedfromotherdesigns．Therefore，theengineeringdatabasesystemmustefficientlymanagetheupdatingprocessesoffldesignandmultipleversionsoffldesignincludingengineeringdrawings[I]．ThehistoricalR—tree(HR—tree)[2]isoneofthespatio—temporaldatastructurestomanageanupdatehistoryofspatialdata．WehavealsodevelopedtheMVR—tree[3]thathadalmostthesamepropertiesoftheHR-tree