Structural problems in linear multivariable systems theory

This thesis discusses some structural problems in linear multivariable systems theory and is based on certain published papers of the candidate. The material divides into two parts, the first of which deals with composite systems and considers the type of structural problems that occur when systems are interconnected to form other (composite) systems. The framework developed in this discussion then leads naturally to a consideration of the theory of invariants of multivariable systems, which forms the second part. [Continues.]