Vertex results for parametric shifted H/sub /spl infin// performance of weighted interval plants

This paper considers the parametric shifted H/sub /spl infin// problem of weighted interval plants. A sufficient condition is obtained on weighting function W(s) such that for any interval plant P(s, q, r) the maximal shifted H/sub /spl infin// norm of W(s)P(s, q, r) is achieved at one of the vertex weighted plants.