Patent ID: 11886786
Assignee: FUZHOU UNIVERSITY
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 5:
6. The two-step X-architecture Steiner minimum tree construction method according to claim 1, wherein the chaotic decreasing mutation strategy in S13 is specifically as follows:
logistic mapping is used to generate a chaotic variable according to the following formula:

zn+1=μ·zn·(1−zn),n=0,1,2,  (3)

wherein, z∈(0,1) is the chaotic variable, and an initial value of the chaotic variable is z0≠{0.25,0.5,0.75}, otherwise, a random sequence generated will be periodic; μ∈[0,4] is a control parameter, if μ=4, the logistic mapping will be represent as complete chaotic dynamics, and a track of the chaotic variable is dense in a whole search space, which means that a chaotic result is within a range [0,1];
to ensure that a particle swarm optimization algorithm has a good global exploration capacity in an earlier stage of iteration and is able to converge rapidly in a later stage and maintain mutation randomness of the particles in the whole iteration process, a chaotically decreasing inertia weight is used:, w
     =
     
      
       
        (
        
         
          w
          init
         
         -
         
          w
          end
         
        
        )
       
       ·
       
        
         Maxiter
         -
         iter
        
        iter
       
      
      +
      
       z
       ·
       
        w
        end
       
      
     
    
   
   
    
     (
     4
     )
    
   
  
 

wherein, winit and wend are an initial value and an end value of the inertia weight w respectively, Maxiter and iter are a maximum iteration and a current iteration respectively, and z is the chaotic variable and follows formula (3); in this way, the inertia weight is chaotic and maintains an original variation trend.