In this paper we give a new formulation of an abstract control problem in terms of a Grushin problem, so that we will reformulate all notions of controllability, observability and stability in a new form that gives readers an easy interpretation of these notions.
@article{arxiv.1306.3836,
title = {Grushin problems and control theory: Formulation and examples},
author = {Akram Ben Aissa},
journal= {arXiv preprint arXiv:1306.3836},
year = {2013}
}