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Necessary and sufficient conditions for stability of a class of interval matrices. (English) Zbl 0611.15017
A n×n interval matrix A I =([p ij ,q ij ]) i,j=1,···,n is said to be stable [completely unstable] if all point matrices AA I are stable [unstable]. If A I contains both, stable as well as unstable point matrices then A I is called of composite stability type. In the first of the two papers, conditions are established that are sufficient for A I to be stable, to be unstable, and to be of composite type. - The second paper is concerned with that special class of interval matrices A I which satisfy q ii <0 (i=1,···,n) and p ij 0 (i,j=1,···,n; ij). For this special class, necessary and sufficient conditions for A I to be stable, to be unstable or to be of composite type are given.
Reviewer: H.Ratschek

MSC:
15A57Other types of matrices (MSC2000)
15A42Inequalities involving eigenvalues and eigenvectors
65G30Interval and finite arithmetic