简介:Amachine,orothertypeof“system”,canoftenbedividedintoseveralsubsystems(components)andthesesubsystemsagaincanbedividedintosevreralsubsystems(secondgeneration).Thisprocessformsasystemtree.Toassessthereliabilityofthemachinebasedondatafromthetrialsofcomponentsofthemachine,virtualsystemmethodisemployed.ItisprovedinthepaperthatthelowerconfidentlimitofthereliabilityofthemachinesetbythevirtualsystemmethodislevelconsistentandasymptoticallyoptimalwhiletheonesetbyLindstrom-Maddensmethodisnot.
简介:Summary1.Thereare12powersystemsincluding5regionalpowersystemswithover1000MWofcapacityeach.In1989CentralandEastChinapowersystemswereinterconnectedbya±500kVHVDCLine.2.Thehierarchicalcontrolorganizationcanbedividedinto5levels,i.e.NCC,6RCCs,25PCCs,250DCCsandmorethan2000CCCs.3.AllcontrolcenterswillbeequippedwithSCADAandEMSinthenearfuture.4.Chinapowersystemhasalarge,dedicatedcommunicationnetworkofitsown.
简介:结合支持向量机和神经网络各自的优点,提出了一种新颖的自适应支持向量回归神经网络(SVR—NN).首先,利用支持向量回归方法确定SVR—NN的初始结构和初始化权值,基于支持向量自适应地构造SVR—NN神经网络的隐层节点;然后,使用退火过程的鲁棒学习算法更新网络节点参数和权值.为了验证所提出方法的有效性,给出了自适应SVR-NN应用于非线性动态系统辨识的实例.仿真结果表明,与以前的神经网络方法相比,基于SVR-NN网络的辨识方案能获得相当好的性能,它具有很快的收敛速度.因此,自适应的SVR—NN为非线性系统辨识提供了极有吸引力的新途径.
简介:摘要:随着城市轨道交通的发展,部分地铁线路运营信号系统已接近设备寿命周期,为消除因设备老化而可能存在的设备隐患,确保客运安全,满足日益增长的运营需求,对信号系统的更新改造势在必行。通过对信号系统更新改造可能存在风险分阶段、分种类地进行辨识,为采取针对性、安全性的措施提供条件。
简介:Inthispaper,wepresentahighspeedautofocussystemformicrosystemapplicationsanddesignalook-up-tablebasedautofocusingalgorithmforapplicationswhenatargetobjectisalwaysvisible,e.g.,manufacturingpartswithalignmentfiducials.Weperformanevaluationof24focusmeasurestoverifythatwhichfocusmeasureisthebestforthelook-up-tablebasedmethod.Fromtheevaluation,wefindthattheChebyshevmoments-basedfocusmeasure(CHEB)isthemostsuitable.Furthermore,wealsodevelopalook-up-tablebasedautofocussystemthatusesCHEBasthefocusmeasure.Intrainingphase,weofflineconstructatablefromtrainingimagesofanobjectthatarecapturedatseverallensdistances.Eachentryoftableconsistsoffocusmeasurecomputedfromimageandlensdistance.Inworkingphase,givenaninputimage,thealgorithmfirstcomputesthefocusmeasureandthenfindsthebestmatchfocusmeasurefromthetableandlooksupthecorrespondinglenspositionformovingitintothein-focusposition.Ouralgorithmcanperformautofocusingwithinonly2stepsoflensmoving.Theexperimentshowsthatthesystemcanperformhighspeedautofocusingofmicroobjects.