基于主观估计法和FMEDA的失效数据分析及应用

针对安全仪表系统安全完整性等级验证（SIL）和机械装置的失效模式、影响及诊断分析（FMEDA）缺乏特定工厂环境、联锁回路中的产品（如阀门、变送器、逻辑控制器等）失效数据这一关键不足;提出了一种基于主观估计法和皮尔逊卡方检验法的失效数据分析方法;并以丙烯腈反应器出口温度高联锁回路中的气动薄膜调节阀为例;应用该方法估计产品寿命分布和实际失效率;应用机械FMEDA法和故障树（FTA）法对回路进行SIL验证;给出改进措施。结果表明;应用该方法获取的产品失效数据对相应联锁回路进行SIL验证比应用国外通用数据库更准确。     

涡街流量计的研究

涡街流量计是目前发展势头十分良好的流量计,在管道流量测量中得到广泛应用,并已跻身通用流量计之列.但涡街流量计尚属发展中流量计,其理论基础和实践经验较薄弱,在使用中,还会出现一些预想不到的问题.为解决这些问题,国内外科研工作者进行了大量的研究工作,并取得了一定进展.从涡街流量计中旋涡分离、涡街发生体形状、涡街信号检测方法及涡街信号分析和处理几方面对国内外研究现状进行了综述,指出研究中存在的难点及今后的研究方向,并提出一种利用涡街原理的新质量流量测量方法.     

基于集成学习的多产品化工过程软测量建模方法

化工过程通常具有非线性、时变以及多产品等特性。针对上述特点,在集成学习框架下建立自适应软测量模型。首先,面向具有多个产品的化工对象,借助k近邻法,以统计假设检验理论为依据,提出一种自适应局部化方法,获得多样性程度高的局部模型集合。然后,根据未知样本量化局部模型的泛化能力,通过选择性集成方法获得主导变量的估计值。此外,为了对主导变量估计值的精度进行评估,基于局部模型泛化误差,给出一种通用性高的模型性能评价方法。在仿真的盘尼西林生产过程上的运行结果验证了所提方法的有效性。     

在线最小二乘支持向量机及其在C8芳烃异构化建模中的应用

The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling of multi-output systems by LS-SVR. The multi-output LS-SVR is derived in detail. To avoid the inversion of large matrix, the recursive algorithm of the parameters is given, which makes the online algorithm of LS-SVR practical. Since the computing time increases with the number of training samples, the sparseness is studied based on the projection of online LS-SVR. The residual of projection less than a threshold is omitted, so that a lot of samples are kept out of the training set and the sparseness is obtained. The standard LS-SVR, nonsparse online LS-SVR and sparse online LS-SVR with different threshold are used for modeling the isomerization of C8 aromatics. The root-mean-square-error (RMSE), number of support vectors and running time of three algorithms are compared and the result indicates that the performance of sparse online LS-SVR is more favorable.     

具有方差和极点约束的不确定系统鲁棒H∞输出反馈控制

针对一类具有范数有界不确定性的连续系统和二次矩阵不等式区域,考虑系统具有方差和区域极点约束 的输出反馈控制器设计问题.为此首先导出闭环系统区域稳定的充分必要条件.然后用线性矩阵不等式方法给出输出反馈控制器存在的一个充分条件.在此充分条件下闭环系统是鲁棒区域稳定的且具有H-infinity性能以及当干扰为白噪声信号时其稳态状态方差有限.接下来用矩阵分解方法给出输出反馈控制器增益矩阵的求解过程.最后通过一个仿真实例说明本文所提出的控制器设计方法的有效性.     

面向内容的有限状态网络服务模型

 提出了一个新的基于有限状态机的网络服务模型,该模型以一种有限状态移动主体(FS-Agent)作为服务的基本单元,分别用服务内容状态机(Content-FS)和服务计算状态机(MACM-FS,即移动主体计算模型)来定义网络服务中的服务内容和服务计算过程,从而构建了一种面向内容的网络服务模型.实验结果表明,该网络服务模型具有良好的可扩展性和较高的网络服务效率.     

An adaptive RNA genetic algorithm for modeling of proton exchange membrane fuel cells

The accurate mathematical model is the key issue to simulation and design of the fuel cell power systems. Aiming at estimating the proton exchange membrane fuel cell (PEMFC) model parameters, an adaptive RNA genetic algorithm (ARNA-GA) which is inspired by the mechanism of biological RNA is proposed. The ARNA-GA uses the RNA strands to represent the potential solutions and new genetic operators are designed for improving the global searching ability. In order to maintain the population diversity and avoid premature convergence, on the basis of the dissimilarity coefficient, the adaptive genetic strategy that allows the algorithm dynamically select crossover operation or mutation operation to execute is proposed. Numerical experiments have been conducted on some benchmark functions with high dimensions. The results indicate that ARNA-GA has better search capability and a higher quality of solutions. Finally, the proposed approach has been applied for the parameter estimation of PEMFC model and the satisfactory results are reached.