13. OPTIMIZATION

CHAPTER 13 'OPTIMISATION' 25 Pressing the "Start" button starts the iterative optimization process. At the top of the dialog box the graph of the optimization history is displayed where the horizontal axis is the number of iterations and the vertical axis is the percentage of improvement of the vector. Below the graph is the progress bar where messages describe the successive stages of the process. Below the progress bar there are six fields which are: The number indicates the number of repetitions so far and in parentheses the time the convergent repetition has been running. OBSERVATION: At iteration numbered 0 is the upper boundary beam, i.e. the beam with largest cross- sections. At iteration numbered 1 is the lower boundary beam, i.e. the beam with smallest cross- sections. In iteration number 2 is the vector as originally designed by the designer and is considered as the reference vector. The percentage described in the current improvement refers to the improvement of the current iteration vector over the original (reference) vector. The percentage described in the maximum improvement refers to the improvement of the best operator achieved so far in any of the previous steps compared to the original operator (reference operator).