We recall the main facts about the representation of regular linear systems, essentially that they can be described by equations of the form x(t) = Ax(t) + Bu(t), y(t) = Cx{t) + Du(t), like finiteâ€¦ (More)

We survey the literature on well-posed linear systems, which has been an area of rapid development in recent years. We examine the particular subclass of conservative systems and its connections toâ€¦ (More)

We extend the well-known principle of Russell which says that, under certain assumptions, stabilizability implies exact controllability. We replace stabilizabilty by the less restrictive requirementâ€¦ (More)

Let A0 be a possibly unbounded positive operator on the Hilbert space H , which is boundedly invertible. Let C0 be a bounded operator from D ( A 1 2 0 ) to another Hilbert space U . We prove that theâ€¦ (More)

The SCOLE (NASA Spacecraft Control Laboratory Experiment) model is considered the best model for the coupled system consisting of a flexible beam with one end clamped and the other end linked to aâ€¦ (More)

This paper investigates the exact controllability of the SCOLE (NASA Spacecraft Control Laboratory Experiment) model. This model describes the movement in one plane of a beam clamped at one end andâ€¦ (More)

A well-posed linear system is said to be optimizable if for any initial state, an input function in L2 can be found such that the state trajectory is in L2 (this is also known as the finite costâ€¦ (More)

We derive a number of equivalent conditions for a linear system to be energy preserving and hence, in particular, well-posed. Similarly, we derive equivalent conditions for a system to beâ€¦ (More)