Advances in Difference Equations
Volume 2004 (2004), Issue 3, Pages 261-271
doi:10.1155/S1687183904310095
  
     
          
          On monotonicity of solutions of discrete-time nonnegative and compartmental dynamical systems
          
            Vijaysekhar Chellaboina1
            , Wassim M. Haddad2
            , James M. Bailey3
             and Jayanthy Ramakrishnan1
          
          1Department Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia 65211, MO, USA
          2School of Aerospace Engineering, Georgia Institute of Technology, Atlanta 30332-0150, GA, USA
          3Department of Anesthesiology, Northeast Georgia Medical Center, Gainesville 30503, GA, USA
          
          Abstract
Nonnegative and compartmental dynamical system models are widespread in biological, physiological, and pharmacological sciences. Since the state variables of these systems are typically masses or concentrations of a physical process, it is of interest to determine necessary and sufficient conditions under which the system states possess monotonic solutions. In this paper, we present necessary and sufficient conditions for identifying discrete-time nonnegative and compartmental dynamical systems that only admit monotonic solutions.