A New Approach for Delivering Customized Security Everywhere: Security Service Chain

Algorithm 2

Service node selection algorithm based on bidirectional memory.

Input: Maximum number of iterations , maximum size of antibody population , maximum

size of memory unit , size of standby unit , initial mutation probability

Output: Memory unit

Initialize ; initializing antibody population , memory unit and standby unit .

Step 1. Generate from by the clone operation :

, where  

Step 2. Update by the mutation operation :

.

Step 3. Generate preponderant antibody population and neighboring antibody population

from by selection operation .

Step 4. If the size of is larger than , sort antibodies by their crowding distances [35] in

descending order and select the top antibodies to form new antibody population ,

otherwise :

.

Step 5. Produce new memory unit by applying study operation on and :

, where  .

Step 6. Update by the self-repairing operation :

.

Step 7. Produce new standby unit by applying replacement operation on and :

.

Step 8. If , output and end, otherwise , ,

, , go to Step 1.