2 . introduced topic - based query topology , which broken out the quantitative limitation of keywords and “ word - mismatch ” 同时,在信息过滤过程中,专题知识库也为文本过滤提供了匹配基向量。
( 3 ) the re - orthonormalization technique is used to solve the loss of orthonormality of basis vector during the classical gmres method solving large - scale three dimensional elasto - static be problems . based on the characteristic of fundamental solution and the coefficient matrix , several precondition methods are studied . by using the technique of re - orthonoramalization and precondition , the practical gmres method is developed based on the classical one ( 3 )采用重正交技术解决了经典gmres方法在求解大型三维弹性静力边界元问题过程中出现的基向量正交性丧失的问题;结合边界元基本解和系数矩阵的特点以及并行化的要求,研究了几种预条件技术;并以重正交技术和预条件技术实现了经典gmres的实用化。
( 3 ) introducing the proportional damping , the finite element formula of structural - acoustic coupled system lined with sound absorbing materials is obtained . mode - superposition technique for modal frequency response analysis of coupled structure - acoustic systems is also used to deal with the sensitivities of the eigenvalues and eigenvectors of coupled systems for the purpose of reducing cavity interior noise in theory 讨论了阻尼降噪问题,建立了有阻尼声振耦合系统的有限元模型,采用振型叠加法,将系统位移转换到以固有振型为基向量,进行结构壁面有吸声材料的声振耦合系统响应的有限元分析与灵敏度分析,推导了比例阻尼条件的灵敏度计算公式。