Title : 
A stability criterion for a nonlinear nonautonomous system
         
        
            Author : 
Willems, Jacques ; Willems, Jan C.
         
        
        
        
        
        
        
            Abstract : 
A stability criterion for a nonlinear nonautonomous feedback system is presented. The criterion is a trade-off between the circle criterion and the Popov criterion by limiting the rate of change of the feedback gain.
         
        
            Keywords : 
Differential equations; Feedback; Frequency; Identity-based encryption; Lyapunov method; Stability criteria; Time varying systems;
         
        
        
            Journal_Title : 
Proceedings of the IEEE
         
        
        
        
        
            DOI : 
10.1109/PROC.1968.6263