基于粗糙神经网络的航空电子传感器故障诊断

针对航空电子传感器系统是由多个子系统所组成的复杂大系统且很难量测系统输入,传统故障诊断方法难以评估这类系统的问题,提出了一种基于粗糙神经网络的航空传感器故障诊断方法。该方法首先运用Kohonen网络对航空电子传感器测量得到的连续数据进行离散化,然后用粗糙集理论进行知识规则的提取,最后用提取的知识作用于一步预测神经网络,用该网络预测结果与航空电子传感器实际输出进行阈值比较,进而进行故障检测。仿真实验和实际应用表明,该方法可行并能有效地检测传感器故障,且故障诊断率高。     

可靠性仿真在模糊故障诊断中的应用

针对模糊故障诊断中传统模糊关系矩阵确定方法不能动态适应具体设备运行状态变化等缺点,提出了基于故障树的可靠性仿真方法,用于确定模糊关系矩阵。该方法首先利用元器件的失效分布数据和设备深层原理性知识建立故障树,进行可靠性仿真,然后根据仿真结果和具体设备的历史故障信息动态计算模糊关系矩阵。给出了该方法的具体应用步骤。实际诊断结果表明,该方法可以有效地提高模糊故障诊断的准确性与针对性。     

基于多Agent电力故障诊断系统体系结构风格的研究

从软件体系结构风格的角度分析研究了基于多Agent的电力故障诊断系统的体系结构,在此基础上抽取出这一类遗留系统特有的包装器体系结构风格,提出了在分散的单个遗留系统周围建立“包装器(wrapper)”这样一种风格,这种风格能够实现遗留系统和目标系统之间集成与交互,从而达到目标系统的要求。这些理论的提出,有助于指导使用多Agent技术对遗留系统进行再开发和再利用的研究。     

A Fault Detection Mechanism in Erasure-Code Byzantine Fault-Tolerance Quorum

Fault-tolerance is increasingly significant for large-scale storage systems in which Byzantine failure of storage nodes may happen. Traditional Byzantine Quorum systems that tolerate Byzantine failures by using replication have two main limitations： low space-efficiency and static quorum variables. We propose an Erasure-code Byzantine Fault-tolerance Quorum that can provide high reliability with far lower storage overhead than replication by adopting erasure code as redundancy scheme. Through read/write operations of clients and diagnose operation of supervisor, our Quorum system can detect Byzantine nodes, and dynamically adjust system size and fault threshold. Simulation results show that our method improves performance for the Quorum with relatively small quorums.     

An approach to 3D NURBS modeling of complex fault network considering its historic tectonics

Fault disposal is a research area that presents difficulties in 3D geological modeling and visualization. In this paper, we propose an integrated approach to reconstructing a complex fault network (CFN). Based on the non-uniform rational B-spline (NURBS) techniques, fault surface was constructed, reflecting the regulation of its spatial tendency, and correlative surfaces were enclosed to form a fault body model. Based on these models and considering their historic tectonics, a method was put forward to settle the 3D modeling problem when the intersection of two faults in CFN induced the change of their relative positions. First, according to the relationships of intersection obtained from geological interpretation, we introduced the topological sort to determine the order of fault body construction and rebuilt fault bodies in terms of the order; then, with the disposal method of two intersectant faults in 3D modeling and applying the Boolean operation, we investigated the characteristic of faults at the intersectant part. An example of its application in hydropower engineering project was proposed. Its results show that this modeling approach can increase the computing efficiency while less computer memory is required, and it can also factually and objectively reproduce the CFN in the engineering region, which establishes a theoretical basis for 3D modeling and analysis of complex engineering geology.     

A New Method for the Detections of Multiple Faults Using Binary Decision Diagrams

With the complexity of integrated circuits is continually increasing, a local defect in circuits may cause multiple faults. The behavior of a digital circuit with a multiple fault may significantly differ from that of a single fault. A new method for the detection of multiple faults in digital circuits is presented in this paper, the method is based on binary decision diagram （BDD）. First of all, the BDDs for the normal circuit and faulty circuit are built respectively. Secondly, a test BDD is obtained by the XOR operation of the BDDs corresponds to normal circuit and faulty circuit. In the test BDD, each input assignment that leads to the leaf node labeled 1 is a test vector of multiple faults. Therefore, the test set of multiple faults is generated by searching for the type of input assignments in the test BDD. Experimental results on some digital circuits show the feasibility of the approach presented in this paper.     

城市活断层控制性浅层地震勘探成果分析

详细分析了活断层控制性浅层地震勘探成果:(1)第四系厚度变化情况及钻孔验证情况;(2)4条目标断层F1,F2,F4,F6的控制情况及形成和发育阶段。得出了相应结论,为后期目标断层的活动性鉴定提供断点的具体位置。     

采用软测量技术提高变风量空调系统的性能

变风量空调箱是变风量空调系统中最关键的设备,其串级控制系统由内、外环2个回路组成.作为内环的风量控制回路对变风量空调的性能起着重要作用.将高等过程控制中的软测量技术应用于内环回路的风量测量,使用软测量技术得到的测量结果对风量传感器的运行进行动态监测,当风量传感器的测量结果与软测量结果相差达到一定程度时,可以认为风量传感器出现了故障,在报警的同时,使用软测量结果临时替代风量传感器作为风量的测量值,仍可以使变风量系统具有较好的运行性能.     

中性点非有效接地系统故障行波暂态特征分析

对于中性点非有效接地的配电系统，基于故障暂态行波信息的线路保护具有重要研究意义。该文以行波理论为基础对线路各种类型故障行波的模分量、行波在配电混合线路和分支线路中的传播特性以及行波在线路末端的反射规律进行了详细分析。研究发现，小电流接地系统单相接地故障时，尽管三相中的稳态线电压对称，但故障暂态过程仍产生行波线模分量；行波在混合线路中发生复杂的折反射，并且经过一段混合线路后，行波波头将发生一定幅值的衰减；行波信号到达线路末端后，电压行波和电流行波在线路末端的反射情况随线路结构不同呈现规律性变化。仿真结果表明了分析结果的正确性。文中分析为基于行波信息的配电线路故障选线及测距的研究奠定了基础.     

自适应小波神经网络在故障诊断中的应用

为提高传统BP神经网络在故障诊断中的效率,提出用小波神经网络加以改进.采用动量法和学习率自适应调整结合的网络训练算法对小波网络的初始参数进行设置,提出自适应小波神经网络的故障诊断方法,详述其诊断原理,并结合实例证实了该方法应用于故障诊断的有效性.