解決材料參數識別問題的傳統方法可以區分為逆推法及直接法兩大類。直接法由 於模式簡單，可以應用於所有型式的問題，但是應用直接法同時識別材料的楊氏係數及柏松 比時，可能無法得到良好的收歛結果。本研究採用BFGS法搜尋最小值下降的方向，並結合DSC 法及Powell's二次內插法決定步長，以改良利用直接法識別土壤彈性參數之收歛性，並和文 獻上曾經發表的案例比較，證實不必推導複雜的控制方程式，直接法仍具有高度精確的收歛 性。由於非線性土壤模式可表示為線性行為的增量關係，所以本研究的成果可以十分容易地 應用於識別非線性土壤模式參數。 關。日前還無法使用直接的測量方法，來評估 足球比賽中的有氧和無氧能量代謝；但可以利用一些間接的測量方法，例如心跳 率、體溫、血乳酸，來評估氧氣的消耗情形。另外，在比賽後也可以測乳酸值， 來做為評估球員的無氧動力。

　　　　　The conventional method for identifying material parameters is classified into the inverse and direct formulations. The direct method can be applied to any type of problems because of its simplicity. However, it has been reported in the literature that poor convergence may occur if the direct method is used to identify simultaneously Young's modulus and Poisson's ratio. In this study, some auxiliary methods, such as BFGS method for searching the minimum value of the direction and combination of DSC method and Powell's method for determining the step size, to enhance the direct method. The proposed method was then used to analyze the examples presented in the literature. Compared with the results in the literature, the proposed method yields a good convergence. Since the nonlinear soil model can be simulated with incremental linear model, the proposed method can be used in the nonlinear soil model as well.