Research ArticleOpen accessPhrase in the titleOn Fractional Hold Devices Versus Positive Realness of Discrete Transfer FunctionsM. de la Sen, A. Bilbao- GuillernaThe appropriate use of fractional order holds (β-FROH) of correcting gains βε[-1,1] as an alternative to the classical zero and first order -holds (ZOH, FOH) is discussed related to the positive realness of the associate discrete transfer functions obtained from a given continuous transfer function. It is proved that the minimum direct input-output gain (i.e. the quotient of the leading … …American Journal of Applied Sciences, Vol. 2, Issue 3 · 31 Mar 2005 · 7,189 accessesView PDFCite
Research ArticleOpen accessIn the keywordsAsymptotic Hyperstability of Dynamic Systems with Point DelaysM. De la SenIt is proved that a linear time-invariant system with internal point delays is asymptotically hyperstable independent of the delays if an associate delay-free system is asymptotically hyperstable and the delayed dynamics are sufficiently small. …American Journal of Applied Sciences, Vol. 2, Issue 9 · 30 Sep 2005 · 6,697 accessesView PDFCite
Research ArticleOpen accessIn the abstractLinks between Dynamic Physical Systems and Operator Theory Issues Concerning Energy Balances and StabilityM. D.L. SenThis study relates the properties of operators with the well- known concepts of positive realness and passivity properties in dynamic systems and their associate transfer functions. Those concepts together with very close related ones are first examined from a physical point of view. Then, they are related to hyper-stability and properties of transfer functions while the hyper-stability theorem is revisited … …American Journal of Applied Sciences, Vol. 1, Issue 3 · 30 Sep 2004 · 6,826 accessesView PDFCite