Table of Contents Linear Algebra and its Applications VOLUMES 203-204, MAY-JUNE, 1994 Third Special Issue on Linear Systems and Control, Part I Special Issue Editors: A. C. Antoulas, M. L. J. Hautus, P. A. Fuhrmann, and Y. Yamamoto Preface 1 Daniel Alpay and Vladimir Bolotnikov (Beer-Sheva, Israel) On a General Moment Problem and Certain Matrix Equations 3 A. C. Antoulas (Houston, Texas) A New Approach to Modeling for Control 45 J. A. Ball (Blacksburg, Virginia), M. A. Kaashoek (Amsterdam, the Netherlands), G. Groenewald (Bellville, South Africa), and J. Kim (Kwangju, Korea) Column Reduced Rational Matrix Function With Given Null-Pole Data in the Complex Plane 67 Joseph A. Ball (Blacksburg, Virginia), Marek Rakowski, and Bostwick F. Wyman (Columbus, Ohio) Coupling Operators, Wedderburn-Forney Spaces, and Generalized Inverses 111 Wu Baowei (Xian, Shaanxi, People's Republic of China) Some Properties of Linear Systems Defined Over a Commutative Banach Algebra 139 Tibor Boros, Ali H. Sayed, and Thomas Kailath (Stanford, California) Structured Matrices and Unconstrained Rational Interpolation Problems 155 Roger Brockett (Cambridge, Massachusetts) Differential Equations and Matrix Inequalities on Isospectral Families 189 Chin Chang and Tryphon T. Georgiou (Minneapolis, Minnesota) Geometric Aspects of the Caratheodory Extension Problem 209 Guanrong Chen (Houston, Texas) and Cetin Kaya Koc (Corvallis, Oregon) Computing Matrix-Valued Nevanlinna-Pick Interpolation 253 Gong-ning Chen and Hui-pin Zhang (Beijing, China) More on Loewner Matrices 265 Carmen Coll, Rafael Bru, Elena Sanchez, and Vicente Hernandez (Valencia, Spain) Discrete-Time Linear Periodic Realization in the Frequency Domain 301 Ruth F. Curtain and Alejandro Rodriguez (Groningen, the Netherlands) Necessary and Sufficient Conditions for J-Spectral Factorizations With a J-Lossless Property for Infinite-Dimensional Systems in Continuous and Discrete Time 327 Leonid Faybusovich (Notre Dame, Indiana) Rational Functions, Toda Flows, and LR-like Algorithms 359 Avraham Feintuch (Beer-Sheva, Israel) Strong Graph Representations for Linear Time-Varying Systems 385 Sven Feldmann (Stuttgart, Germany) and George Heinig (Leipzig, Germany) Uniqueness Properties of Minimal Partial Realizations 401 Michel Fliess (Gif-sur-Yvette, France) Une Interpretation Algebrique de la Transformation de Laplace et des Matrices de Transfert 429 Ciprian Foias (Bloomington, Indiana), Arthur Frazho (West Lafayette, Indiana), and Allen Tannenbaum (Haifa, Israel) On Combined H-H2 Suboptimal Interpolants 443 P. A. Fuhrmann (Beer-Sheva, Israel) A Duality Theory for Robust Stabilization and Model Reduction 471 Hisaya Fujioka and Shinji Hara (Yokohama, Japan) State Covariance Assignment Problem With Measurement Noise: A Unified Approach Based on a Symmetric Matrix Equation 579 Ton Geerts (Tilburg, the Netherlands) Linear-Quadratic Control With and Without Stability Subject to General Implicit Continuous-Time Systems: Coordinate-Free Interpretations of the Optimal Costs in Terms of Dissipation Inequality and Linear Matrix Inequality: Existence and Uniqueness of Optimal Controls and State Trajectories 607 Tomomichi Hagiwara and Mituhiko Araki (Kyoto, Japan) A Successive Optimal Construction Procedure for State Feedback Gains 659 Author Index 674