This paper discusses the drawing of hyperbola normal through a point outside the hyperbola and points out the unsolvability of geometric drawing method and the unintegrality of optimization method .

对过双曲线外一定点的 法线作图问题作了探讨，提出了几何作图法的 不 可 解 性及优化法 解的不全性。

The unsolvability of implicit equations existing in the inversion algorithm in the inverse system method ( ISM ) is considered and a constructive inversion algorithm is presented for general nonlinear systems so as to avoid solving implicit equations via elimination method .

针对由于逆系统方法之求 逆算法中求解隐函数方程的 困难，通过消元法避开对隐函数方法的求解，提出了一般非线性多变量系统的构造性求逆算法。

Quantitative Analysis and Online Recovering Control of Power Flow Unsolvability

电力 系统 潮流 计算 不 收敛 的 机理分析及其在线恢复控制