This book presents a concise study of controllability theory of partial differential equations when they are equipped with actuators and/or sensors that are finite dimensional at every moment of time. Based on the authors extensive research in the area of controllability theory, this monograph specifically focuses on the issues of controllability, observability, and stabilizability for parabolic and hyperbolic partial differential equations. The topics in this book also cover related applied questions such as the problem of localization of unknown pollution sources based on information obtained from point sensors that arise in environmental monitoring. Researchers and graduate students interested in controllability theory of partial differential equations and its applications will find this book to be an invaluable resource to their studies.

Alexander Y. Khapalov is a professor in the Department of Mathematics at Washington State University. 

1. Introduction.- Part I: 2. Continuous observability of the heat equation under a single mobile point sensor.- 3. Continuous observability of the 2-nd order paragolic equations under degenerate mobile sensors.- Part II: 4. Behavior of solutions of the semilinear heat equation in vanishing time and controllability.- 5. Controllability of the semiliniear heat equation with sublinear term and degenerate actuator.- 6. Controllability of the semilinear reaction-diffusion equation with degenerate actuator.- 7. Semilinear parabolic equations: Mobile point controls vs the locally distributed ones.- Part III: 8. Degenerate sensors in source localization and sensor placement problems.- Part IV: 9. Continuous observability of hyperbolic equations under degenerate sensors.- 10. Controllability of the wave equation governed by mobile point controls.- Part V: 11. Exponential decay for the wave equation equipped with a point damping device.- 12. A vibrating string with shuttle-like point dampers andrelated observability properties.- References.