|   | 
           | 
            |        
         
         
          |   | 
          Volume 10, Issue 3, Article 68 | 
           | 
         
         
           | 
           | 
           | 
           | 
         
       |   | 
             An Unconstrained Optimization Technique for Nonsmooth Nonlinear Complementarity Problems
 
  | 
          
          |   | 
            | 
          Authors:  | 
          M. Tawhid,  | 
            | 
         
         
          |   | 
            | 
          Keywords: 
             | 
          Nonlinear complementarity problem, unconstrained minimization, NCP function, merit function, regularity conditions, nonsmooth function, descent algorithm. | 
            | 
         
         
          |   | 
            | 
          Date Received: 
             | 
          13/07/2009 | 
            | 
         
         
          |   | 
            | 
          Date Accepted: 
             | 
          22/07/2009 | 
            | 
         
         
          |   | 
            | 
          Subject Codes: | 
           
             90C33, 90C20, 90C56, 49J52 
           | 
            | 
          
          |   | 
            | 
          Editors:  | 
          Ram U. Verma,   | 
            | 
         
         
          |   | 
         
         
           | 
           | 
           | 
           | 
           | 
         
         
          |   | 
            | 
          Abstract: | 
           
              In this article, we consider an unconstrained minimization formulation of the nonlinear complementarity problem NCP  when the underlying functions are  -differentiable but not necessarily locally Lipschitzian or directionally differentiable. We show how, under appropriate regularity conditions on an  -differential of  , minimizing the merit function corresponding to   leads to a solution of the nonlinear complementarity problem. Our results give a unified treatment of such results for  -functions, semismooth-functions, and for locally Lipschitzian functions. We also show a result on the global convergence of a derivative-free descent algorithm for solving nonsmooth nonlinear complementarity problem. 
             
          
         |  
         
           | 
           | 
           | 
           | 
           | 
         
         
          |   | 
            | 
            | 
           
           |  
         |  
         
          |   | 
            | 
            | 
           | 
            | 
          
         
         
        |