简介:A3-D数字核心描述岩石的毛孔空间微观结构。X光检查微CT扫描是最精确、直接却昂贵的方法获得3-D数字核心。在这研究,我们建议联合沉积模拟的一个混合方法并且退火模仿(SA)产生3-D的方法数字核心基于岩石的2-D图象。有沉积模拟的方法开始造3-D数字核心,它是为SA方法的起始的配置。我们用SA方法更新起始的数字核心匹配2-D岩石图象的自相关功能并且最后造最后的3-D数字核心。与典型SA方法相比,混合方法显著地减少了计算时间。本地孔理论被用于份量上比较重建的3-D有X光检查微CT3-D图象的数字核心。结果显示3-D数字核心由混合方法重建了有同质和X光检查微CT图象的类似于那些的几何连接。形成因素和重建的3-D的渗透数字核心用有限元素方法被估计(女性)并且格子Boltzmann方法(LBM)分别地。模仿的结果在对试验性的大小的好同意。模拟结果的比较建议数字核心由更多仔细独自比典型SA方法反映真运输性质的混合方法重建了。
简介:SegmentationandedgeregulationarestudieddeeplytoextractbuildingsfromDSMdataproducedinthispaper.Buildingsegmentationisthefirststeptoextractbuildings,andanewsegmentationmethod-adaptiveiterativesegmentationconsideringratiomeansquare-isproposedtoextractthecontourofbuildingseffectively.Asub-image(suchas50×50pixels)oftheimageisprocessedinsequence,theaveragegraylevelanditsratiomeansquarearecalculatedfirst,thenthresholdofthesub-imageisselectedbyusingiterativethresholdsegmentation.Thecurrentpixelissegmentedaccordingtothethreshold,theaver-agegraylevelandtheratiomeansquareofthesub-image.Theedgepointsofthebuildingaregroupedaccordingtotheazimuthofneighborpoints,andthentheoptimalazimuthofthepointsthatbelongtothesamegroupcanbecalculatedbyusinglineinterpolation.
简介:Astheexplorationandexploitationofoilandgasproliferatethroughoutdeepwaterarea,therequirementsonthereliabilityofdynamicpositioningsystembecomeincreasinglystringent.Thecontrolobjectiveensuringsafetyoperationatdeepwaterwillnotbemetbyasinglecontrollerfordynamicpositioning.Inordertoincreasetheavailabilityandreliabilityofdynamicpositioningcontrolsystem,thetripleredundancyhardwareandsoftwarecontrolarchitecturesweredesignedanddevelopedaccordingtothesafespecificationsofDP-3classificationnotationfordynamicallypositionedshipsandrigs.Thehardwareredundantconfigurationtakestheformoftriple-redundanthotstandbyconfigurationincludingthreeidenticaloperatorstationsandthreereal-timecontrolcomputerswhichconnecteachotherthroughdualnetworks.Thefunctionofmotioncontrolandredundancymanagementofcontrolcomputerswereimplementedbysoftwareonthereal-timeoperatingsystemVxWorks.Thesoftwarerealizationoftaskloosesynchronization,majorityvotingandfaultdetectionwerepresentedindetails.Ahierarchicalsoftwarearchitecturewasplanedduringthedevelopmentofsoftware,consistingofapplicationlayer,real-timelayerandphysicallayer.ThebehavioroftheDP-3dynamicpositioningcontrolsystemwasmodeledbyaMarkovmodeltoanalyzeitsreliability.Theeffectsofvariationinparametersonthereliabilitymeasureswereinvestigated.Thetimedomaindynamicsimulationwascarriedoutonadeepwaterdrillingrigtoprovethefeasibilityoftheproposedcontrolarchitecture.
简介:依据《中华人民共和国测绘法》、《测绘资格审查认证管理规定》和《(测绘资格证书)分级标准》,经测绘单位申请,各市(地)测绘管理办公室初审(含房产测绘业务范围的申请单位经省建设厅初审),山西省测绘局批准,2003年度全省共38家单位取得《测绘资格证书》、6家单位进行测绘资格等级升级。