Discrete Dynamics in Nature and Society
Volume 2009 (2009), Article ID 306425, 10 pages
doi:10.1155/2009/306425
  
     
          
          Feedback Control Variables Have No Influence on the Permanence of a Discrete N-Species Cooperation System
          
            Liujuan Chen1
            , Xiangdong Xie2
             and Lijuan Chen3
          
          1Ministry of Science Training, Fujian Institute of Education, Fuzhou, Fujian 350001, China
          2Department of Mathematics, Ningde Teachers College, Ningde, Fujian 352100, China
          3College of Mathematics and Computer Science, Fuzhou University, Fuzhou, Fujian 350002, China
          
          Abstract
A new set of sufficient conditions for the permanence of a discrete N-species cooperation system with delays and feedback controls are obtained. Our result shows that feedback control variables have no influence on the persistent property of the discrete cooperative system, thus improves and supplements the main result of F. D. Chen (2007).