STABILITY 20/12 



These results prove little ; but they suggest that the proba- 

 bility of stability is small in large systems assembled at random. 

 It is suggested, therefore, that large systems should be assumed 

 unstable unless evidence to the contrary can be produced. 



References 



Ashby, W. Ross. The effect of controls on stability. Nature, 155, 242 ; 



1945. 

 Idem. Interrelations between stabilities of parts within a whole dynamic 



system. Journal of comparative a?id jihysiological Psychology, 40, 1 ; 



1947. 

 Idem. The stability of a randomly assembled nerve-network. Electro- 

 encephalography and clinical neurophysiology, 2, 471 ; 1950. 

 Frazer, R. A., and Duncan, W. J. On the criteria for the stability of small 



motions. Proceedings of the Royal Society, A, 124, 642 ; 1929. 

 Hurwitz, A. t)ber die Bedingungen, unter welchen eine Gleichung nur 



Wurzeln mit negativen reellen Teilen besitzt. Mathematische Annalen, 



46, 273 ; 1895. 

 Nyquist, H. Regeneration theory. Bell System technical Journal, 11, 126 ; 



1932. 



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