https://scholars.lib.ntu.edu.tw/handle/123456789/169151
Title: | 利用小波理論建立水文系統的時間和空間尺度參數化方法 (II) Development of a Methodology for Parameterization of Time scale and Space scale in Hydrological Systems Based on Wavelet Theory (II) |
Authors: | 徐年盛 | Keywords: | 序率方法;傅利葉轉換;非定常性;小波積分轉換;尺度效應;Stochastic approaches;Fourier transform;nonstationarity;wavelet transform;scale effects | Issue Date: | 2004 | Publisher: | 臺北市:國立臺灣大學土木工程學系暨研究所 | Abstract: | 幾乎所有地下水流的流動現象均涉及 時間變異的問題,利用序率方法從事水文 現象之分析時,經常利用在時間域和頻率 域之轉換以獲得其間相關性的優點,傅利 葉轉換應用在求解定常性序率水文過程成 功的地方,就是把相關函數和頻譜密度函 數關聯起來,而傅利葉分析是屬於全域的 轉換,廣泛的應用於定常性的問題,但對 於非定常性及瞬態性問題則不適合。本研 究將類比傅利葉轉換的概念,利用小波積 分轉換式導入地下水系統的控制方程式的 變數中以求得小波頻譜密度函數,並以一 維地下水系統為例,推導適合處理非定常 性地下水系統之序率水文方程式,文中並 對處理非定常性或異質性資料的考量原則 加以探討。 Subsurface flow phenomena almost always involve time variation. Stochastic approaches are usually utilized for describing temporal and/or spatial variability, with emphasis on the use of stochastic stationary processes and their characterization in terms of covariance function and spectra. Standard Fourier transform is a kind of global-domain analyzing tool, which treats data as samples of continuous and in principle infinitely long series of superimposed waves. It is suited for analyzing stationary signals but not for describing transient and non-stationary ones. With an analogous concept, the wavelet transform is induced into a one dimensional stochastic ground water system, and then the properties of the wavelet transform could be harnessed in a more useful way. The criterions and considerations for examining stationarity are also discussed in this paper. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/2868 | Other Identifiers: | 922313B002101 | Rights: | 國立臺灣大學土木工程學系暨研究所 |
Appears in Collections: | 土木工程學系 |
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922313B002101.pdf | 601.45 kB | Adobe PDF | View/Open |
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