Stability condition of the proportional control algorithm is given for a fixed target. 針對固定目標，文中給出了比例控制算法的穩定性條件。
The stability of the helical equilibrium is analyzed with phase plane method, and an analytical criterion of stability is revealed. 用相平面法分析螺旋線平衡的穩定性，導出解析形式的穩定性條件。
An ordinary star such as the sun is a splendidly controlled machine that can go on operating under stable conditions for an immense length of time. 象太陽那樣的一顆普通恒星就是一架十分巧妙的可控機器，它能在穩定條件下持續運轉異常長的時間。
Due to the idea of parameter-dependent Lyapunov stability, the obtained robust stability condition has less conservativeness than the one based on quadratic stability. 因為使用了參數依賴的李亞普諾夫穩定性思想，此魯棒穩定條件比基于二次穩定概念的穩定條件的保守性更小。
