Nowadays there is great interest in structural damage detection using non-destructive tests. Once the failure is identified, as for instance a crack, it is possible to plan the next step based on a predictive maintenance ...

A novel formulation for the problem of optimal controller order reduction for continuous-time linear systems is presented. The H2 or the H∞-norms of the error realization between the full and the reduced order controlled ...

The paper deals with operators on Norm Hilbert spaces over a Krull valued field K. By using carefully selected equivalent norms (i) the perturbation theory of Fredholm operators (see Ochsenius and Schikhof (2010) [7]) is ...

Let L(H) be the algebra of bounded operators on a complex separable Hilbert space H.  Let N be a unitary invariant norm  defined on a norm ideal I ⊆ L(H)$. Given two positive invertible operators P, Q ∈ L(H) and k ∈ (-2,2], ...

The theory of X-normed spaces over non-Archimedean valued fields with valuations of higher rank was introduced by H. Ochsenius and W. H. Schikhof in [1] and further developed in [2–4, 6, 7] and [5]. In order to obtain ...

A conjecture posed by S. Hayajneh and F. Kittaneh claims that given A, B positive matrices, 0≤t≤1, and any unitarily invariant norm the following inequality holds{triple vertical-rule fence}AtB1-t+BtA1-t{triple vertical-rule ...