简介:摘要:目的 分析牙椅故障情况,为同行维修牙椅提供参考。方法 统计2017~2018年牙椅故障报修情况。结果 每月故障中,5、9月份故障最多,各占16.4%;各科室中,口内故障最多,占50.7%;各种故障中,手机无水和漏水情况最多,占13.7%。结论 设备科不仅要及时维修牙椅,平时也要定期做好维保,保障医疗质量和患者安全。
简介:摘要:直流系统接地故障在变电运行中的常见故障,发生一点接地时,必须及时处理,否则,当再发生一点接地时,容易造成保护勿动或拒动现象,造成控制回路失去电源,更严重的时造成电力系统震荡甚至瓦解。
简介:ThisstudyconcernssecurityissuesoftheemergingWirelessBodySensorNetwork(WBSN)formedbybiomedicalsensorswornonorimplantedinthehumanbodyformobilehealthcareappli-cations.Anovelauthenticatedsymmetric-keyestablishmentschemeisproposedforWBSN,whichfullyexploitsthephysiologicalfeaturesobtainedbynetworkentitiesviathebodychannelavailableinWBSNbutnototherwirelessnetworks.Theself-definedIntrinsicSharedSecret(ISS)isusedtoreplacethepre-deploymentofsecretsamongnetworkentities,whichthuseliminatescentralizedservicesorau-thoritiesessentialinexistingprotocols,andresolvesthekeytransportprobleminthepuresymmet-ric-keycryptosystemforWBSNaswell.Thesecuritypropertiesoftheproposedschemearedemon-stratedintermsofitsattackcomplexityandthetypesofattacksitcanresist.Besides,theschemecanbeimplementedunderalight-weightwayinWBSNsystems.DuetotheimportanceoftheISSconcept,theanalysisonusingfalseacceptance/falserejectionmethodtoevaluatetheperformanceofISSforitsusageintheschemeisalsodemonstrated.
简介:Recently,ithasbeenseenthattheensembleclassifierisaneffectivewaytoenhancethepredictionperformance.However,itusuallysuffersfromtheproblemofhowtoconstructanappropriateclassifierbasedonasetofcomplexdata,forexample,thedatawithmanydimensionsorhierarchicalattributes.Thisstudyproposesamethodtoconstructeanensembleclassifierbasedonthekeyattributes.Inadditiontoitshigh-performanceonprecisionsharedbycommonensembleclassifiers,thecalculationresultsarehighlyintelligibleandthuseasyforunderstanding.Furthermore,theexperimentalresultsbasedontherealdatacollectedfromChinaMobileshowthatthekey-attributes-basedensembleclassifierhasthegoodperformanceonbothoftheclassifierconstructionandthecustomerchurnprediction.
简介:Theresultsofastudyonthekeytechnologyofusingshellsand,akindofseasand,asbackfillforseareclamationaredescribedbriefly.Laboratorytestsshowthatthephysicalandmechanicalpropertiesofshellsandareasgoodasnormalquartzsand.Basedonthechemicaltestanddurabilitytestofshellsanditcouldbeconcludedthattheinfluenceofcorrosionofshellsandbyacidrainandseawatermightbeignoredintheevaluationofthesafetyanddurabilityoftheengineeringproject.Theresultsoffieldimprovementtestsshowthatthebearingcapacityofshellsandbackfillfoundationismorethan200kPaaftervibroflotationimprovementordynamiccompactionimprovement.Theshellsandisagoodbackfillmaterialforseareclamation.