回娘家-心得交流(海大教研15年).ppt

回娘家-心得交流(海大教研15年) J T Chen(陳正宗), Life-time Distinguished Prof. Principal value in who’s sense Common sense Riemann sense Lebesgue sense Cauchy sense €Hadamard sense (elasticity) Mangler sense (aerodynamics) Liggett and Liu’s sense The singularity that occur when the base point and field point coincide are not integrable. (1983) 教學經驗分享 教學的開始(two students story) 學生的辛苦(大武崙上大夜班) 3 by 3 反矩陣算法 教學研究整合 (國際SCI,EI期刊) 教學輔具(Mathematica 與動畫) 網址：.tw/~msvlab/課程相關 Top 25 scholars on BEM/BIEM since 2001 Disclaimer (commercial code) The concepts, methods, and examples using our software are for illustrative and educational purposes only. Our cooperation assumes no liability or responsibility to any person or company for direct or indirect damages resulting from the use of any information contained here. inherent weakness ? misinterpretation ? User 當自強 Nonuniqueness in numerical methods Nonlinear equation (spurious root) Finite difference method spurious eigenvalue Finite element method meshless methods spurious mode Boundary element method spurious eigenvalues fictitious frequency Boundary element method degenerate scale Why spurious solution occurs 假根、浮根、溢根(Spurious Eigenvalue) h=0.05 Solid mechanics (spurious mode) Numerical phenomena(Degenerate scale) Nonuniqueness in BEM for exterior acoustics BEM for exterior acoustics Numerical phenomena(Fictitious frequency) Numerical phenomena(Spurious eigensolution) 馮康 定理 同一個物理或工程問題，可以有各種不同的數學模式來模擬。 這些數學模式在物理上是等效的(Equivalent) 。但在離散後，數值的實踐(Implementation)就不見得等效。 唯有在不同的數值方法中，儘量保有問題的基本特徵，方是做計算數學與計算力學的最高指導原則 ?????????????????????????????????? ???????????????????????????????????? ?????????????????????????????? Two points 應力所所友 命運共同体 不太會寫報告 ?????????????????????? * * Taiwan Ocean University April 14 14:00, 2008 (應力所回娘家 2008.ppt) National Taiwan Ocean University MSVLAB (海大河工系) Department of Harbor and River Engineeri