三防决策支持系统中空间索引结构与空间查询算法研究

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1、河南大学硕士学位论文三防决策支持系统中空间索引结构与空间查询算法研究姓名：丁海燕申请学位级别：硕士专业：计算机应用技术指导教师：郑逢斌20100501第1I页河南大学硕士研究生学位论文AbstractWithrapiddevelopmentofcomputertechnologyandexplosionofsocialneeds，spmialinformationsystemtechnologyhasdevelopedrapidlyanditsapplicationareaisincreasinglyexpanding．

2、Thefaceofmassiveandcomplexspatialdatamakesitanimportantresearchareaforrecentspatialinformation-systemtoimprovetheefficiencyofqueryinginformation．Therefore，settingthesupportingsystemofthreeresistancesasbackground,thepresentpaperhasselectedtheindexstructureandquery

3、algorithmsinthespacesystemasthesubjectandmadethefollowingcontributions：1)Improvementofspatialsystemindex．Spatialindexingefficiencyisoftenevaluatedbyseveralaspectsastheindex’Sstorageefficiency,queryefficiencyandupdateefficiency．Butthetruthisthatit’Sdifficulttodesi

4、gnaspatialindexstructureinwhichalltheaboveaspectscailbefullyfulfilled．Base，．donthetypesofspatialdataanditsfunctionalcharacteristic，aswellasananalysis。oftheefficiencyofeachspatialindex，thepresentpaperhastheoreticallyconstructed．aspatialindexstructure，aHilbertcodin

5、g—basedfixedgridindex，whichwouldbesui—ta—bleforthesupportingsystemofthreeresistances．ExperimentshaveshowedthatthisindexstructureCallimprovetheefficiencyofspatialquerysystemandoptimizethesystemperformance．2)Designoftheconstructionofthesystemspatialindexalgorithm．T

6、hedesignoftheconstructionofthesystemspatialindexalgorithmhasfollowedthreesteps．First，dividethegrd．Accordingtotheactualsituation，the=画vholemaphasbeendividedintotwotothe2N-thpower酣ds．Second，establishthe每ridindextable．Instoringindexinformation,theHilbertcodewhichisg

7、eneratedfromthelinenumberandcohmmnumberwouldbetakenastheexclusiveidentificationforthegird．Third，scanallgraphicsobjects，andremovethecoordinatesinformation．ThenjudgeitspropergridanditsIntersectiongrids，andfinallyInsertthecorrespondingindexintoindexfiles．3)Improveme

8、ntoftheshortestpathDijkstraalgorithm．ThemaindrawbacksofDijkstraalgorithmareinthefieldsofstoragestructureandthenextnearestquerynode．Thepresentpapermainlymadeimp