頁籤選單縮合
題 名 | 吉布斯問題的一個實務解法=A Wavelet-Based Method to Solve the Gibbs Problem in Practice |
---|---|
作 者 | 蔡展榮; | 書刊名 | 中國土木水利工程學刊 |
卷 期 | 11:3 1999.09[民88.09] |
頁 次 | 頁543-550 |
分類號 | 440.11 |
關鍵詞 | 吉布斯現象; 地形斷線; 碎形訊號; 數值表面模型; Gibbs phenomenon; Topographic break-line; Fractal signal; Digital surface model; |
語 文 | 中文(Chinese) |
中文摘要 | 本文應用實務資料的觀測誤差與垂直誤差的這兩種誤差現象並配合筆者提出的小 波近似法來進行參考點之間的內插/近似,使得吉布斯現象很容易地會快速消失,俾以實現 一個精確的斷線/斷點訊號之內插/近似。由實驗結果顯示,此一方法可以在實務應用上輕易 地消除理論上的吉布斯現象對精確的斷線/斷點訊號描述之影響及限制,讓吾人能在實務中 依舊可以有效地表達包含斷線/斷點的不連續訊號以及一個各處平滑程度均彼此不同的碎形 訊號。此一方法可以提供許多方面的實務應用,例如海水表面地形學/數值海水表面模型、 三維城市模型之表達、不規則的地籍圖變形改正、數值地表模型、…等等。 |
英文摘要 | This paper proposes a wavelet-based method to solve the Gibbs problem encountered in practice. The method is derived from the fact that all measured data have observation errors and almost all natural or artificial break-lines/points in practice are not theoretically exact, e.g., a wall surface of a reconstructed building is often not exactly perpendicular to the earth surface. The observation errors and a very small discrepancy of the perpendicular condition for break-lines/points could cause the Gibbs phenomenon to become very insignificant, if the wavelet-based approximation method given by is utilized. Such an insignificant Gibbs phenomenon exists only theoretically and is not fully visible in practice, so that it can be supposed disappear in practice. The experiment results show that the above-mentioned idea is correct and the method can be applied to solving the Gibbs problem in practice. It can represent fractal signals inclusive of break-lines/points quite easily. Typical areas of application s include the sea surface topography/digital sea surface model, 3D-city modeling, corrections of irregular deformations of cadastral maps, digital terrain model,..., etc. |
本系統中英文摘要資訊取自各篇刊載內容。