A geometic proof of the Jordan normal form is given by the Euclidean algorithm and the fundamental theorem of algebra, and its works in the algebraic geometry are also given. 摘要文章利用輾轉相除法和代數學基本定理得到了若當標準型的幾何法證明，並指出了其在代數幾何上的作用。
The absolute stability of a class of indirect control systems by applying the theory of Hermitian quadratic form and Jordan normal form was studied. 利用厄米特二次型和若當標準形理論研究了一般間接控制系統的絕對穩定性問題，給出了絕對穩定性的代數形式的判別準則。
