UNIT 1
UNIT 2
Unit 3
Unit 4
Introduction
- Simulated Annealing (SA) is inspired by a physical process called annealing, where metals are heated and then cooled slowly to reach a stable, low-energy state (crystalline structure). This idea is applied to optimization problems, where the goal is to find the "optimal" or "near-optimal" solution.
Physical Annealing Process
- Heating Phase: At high temperatures, particles in a metal gain energy and move randomly.
- Cooling Phase: As the temperature drops, particles settle into a stable, low-energy configuration.
- For this to work well, the cooling must be done very slowly; otherwise, the material may not reach its optimal state (ground energy).
Simulated Annealing Analogy
- In optimization problems:
- The state of the metal corresponds to a potential solution to the problem.
- The energy corresponds to the cost function being minimized.
- The temperature controls the randomness of the search for better solutions.
Algorithm Overview
- Start with a random solution and an initial high temperature.
- Move to a neighboring solution:
- If it improves the cost (lower energy), accept it.
- If it’s worse, accept it with a certain probability, which decreases as temperature drops.
- Gradually lower the temperature according to a cooling schedule.
- Stop when the system is "frozen" (low temperature) or no better solutions are found.