Page 95 - DCAP601_SIMULATION_AND_MODELING
P. 95

Unit 6: Discrete System Simulation (III)



            A classic example is Rabin’s algorithm for primality testing: for any n which is not prime, a  Notes
            random x has at least a 75% chance of proving that n is not prime. Hence, if n is not prime, but x
            says that it might be, we have observed at most a 1-in-4 event. If 10 different random x say that
            “n is probably prime” when it is not, we have observed a one-in-a-million event.
            In general a Monte Carlo algorithm of this kind produces one correct answer with a guarantee
            n is composite, and x proves it so, but another one without, but with a guarantee of not getting
            this answer when it is wrong too often — in this case at most 25% of the time.

            Monte Carlo and Random Numbers

            Interestingly, Monte Carlo simulation methods do not always require truly random numbers to
            be useful — while for some applications, such as primality testing,  unpredictability is vital.
            Many of the most useful techniques use deterministic, pseudo-random sequences, making it
            easy to test and re-run simulations. The only quality usually necessary to make good simulations
            is for the pseudo-random sequence to appear “random enough” in a certain sense.
            What this means depends on the application, but typically they should pass a series of statistical
            tests. Testing that the numbers are uniformly distributed or follow another desired distribution
            when a large enough number of elements of the sequence are considered is one of the simplest
            and most common ones.

            General


            Statistics Portal

            1.   Auxiliary field Monte Carlo
            2.   Bootstrapping (statistics)
            3.   Demon algorithm
            4.   Evolutionary Computation
            5.   Las Vegas algorithm
            6.   Markov chain

            7.   Molecular dynamics
            8.   Monte Carlo option model
            9.   Monte Carlo  integration
            10.  Quasi-Monte Carlo method
            11.  Random number generator
            12.  Randomness
            13.  Resampling (statistics)

            Application Areas

            1.   Graphics, particularly for ray tracing; a version of the Metropolis-Hastings algorithm is
                 also used for ray tracing where it is known as Metropolis light transport
            2.    light transport in biological tissue
            3.   Monte Carlo methods in finance





                                             LOVELY PROFESSIONAL UNIVERSITY                                   89
   90   91   92   93   94   95   96   97   98   99   100