2 . introduced topic - based query topology , which broken out the quantitative limitation of keywords and “ word - mismatch ” 同時,在信息過濾過程中,專題知識庫也為文本過濾提供了匹配基向量。
( 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 )采用重正交技術解決了經典gmres方法在求解大型三維彈性靜力邊界元問題過程中出現的基向量正交性喪失的問題;結合邊界元基本解和系數矩陣的特點以及并行化的要求,研究了幾種預條件技術;并以重正交技術和預條件技術實現了經典gmres的實用化。
( 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 討論了阻尼降噪問題,建立了有阻尼聲振耦合系統的有限元模型,采用振型疊加法,將系統位移轉換到以固有振型為基向量,進行結構壁面有吸聲材料的聲振耦合系統響應的有限元分析與靈敏度分析,推導了比例阻尼條件的靈敏度計算公式。