The lectures contained in this book were presented at Harvard University in June 1979. The workshop at which they were presented was the third such on algebro-geometric methods. The first was held in 1973 in London and the emphasis was largely on geometric methods. The second was held at Ames Research Center-NASA in 1976. There again the emphasis was on geometric methods, but algebraic geometry was becoming a dominant theme. In the two years after the Ames meeting there was tremendous growth in the applications of algebraic geometry to systems theory and it was becoming clear that much of the algebraic systems theory was very closely related to the geometric systems theory. On this basis we felt that this was the right time to devote a workshop to the applications of algebra and algebraic geometry to linear systems theory. The lectures contained in this volume represent all but one of the tutorial lectures presented at the workshop. The lec ture of Professor Murray Wonham is not contained in this volume and we refer the interested to the archival literature. This workshop was jointly sponsored by a grant from Ames Research Center-NASA and a grant from the Advanced Study Institute Program of NATO. We greatly appreciate the financial support rendered by these two organizations. The American Mathematical Society hosted this meeting as part of their Summer Seminars in Applied Mathematics and will publish the companion volume of con tributed papers."

The lectures contained in this book were presented at Harvard University in June 1979. The workshop at which they were presented was the third such on algebro-geometric methods. The first was held in 1973 in London and the emphasis was largely on geometric methods. The second was held at Ames Research Center-NASA in 1976. There again the emphasis was on geometric methods, but algebraic geometry was becoming a dominant theme. In the two years after the Ames meeting there was tremendous growth in the applications of algebraic geometry to systems theory and it was becoming clear that much of the algebraic systems theory was very closely related to the geometric systems theory. On this basis we felt that this was the right time to devote a workshop to the applications of algebra and algebraic geometry to linear systems theory. The lectures contained in this volume represent all but one of the tutorial lectures presented at the workshop. The lec ture of Professor Murray Wonham is not contained in this volume and we refer the interested to the archival literature. This workshop was jointly sponsored by a grant from Ames Research Center-NASA and a grant from the Advanced Study Institute Program of NATO. We greatly appreciate the financial support rendered by these two organizations. The American Mathematical Society hosted this meeting as part of their Summer Seminars in Applied Mathematics and will publish the companion volume of con tributed papers."

In its broadest sense, nonlinear synthesis involves in fact the synthesis of sometimes so phisticated or complex control strategies with the aim of prescribing, or at least influencing, the evolution of complex nonlinear systems. Nonlinear synthesis requires the development of methodologies for modeling complex systems, for the analysis of nonlinear models, and for the systematic design of control schemes or feedback laws which can achieve a wide variety of prescribed objectives. The modeling, analysis and control of complex systems in the face of uncertainty form on of the major components of the current research program in the Department of Systems and Decision Sciences (SDS) at the International Institute for Applied Systems Analysis (IIASA). In June 1989, a IIASA workshop on Nonlinear Synthesis, sponsored by SDS, was held in Sopron, Hungary. We are proud to present this volume as the proceedings of this workshop, a workshop attened by prominent researchers in nonlinear systems from both the East and the West. Since the promotion and encouragement of scientific cooperation between researchers in the East and in the West is one of the goals at IIASA, we feel the Sopron Conference on Nonlinear Synthesis was very successful. Moreover, we were especially pleased by the impressive new advances presented at the workshop which, in this volume, are now part of the conference record."