학위논문(박사) - 한국과학기술원 : 수학전공, 2003.2, [ [iii], 101 p. ]The aim of this work is to investigate computational structures of random phenomena in various fields such as pseudorandom number generations and ergodic theory.
First, we propose new empirical tests for pseudorandom numbers based on random walks on Zn=0,1,…,n−1. The tests focus on the distribution of arrival time at zero starting from a fixed point x neq 0. Three types of random walk are defined and the exact probability density of the arrival time for each version is obtained by the Fourier analysis on finite groups. The test results show hidden defects in some generators such as combined multiple recursive generators and Mersenne Twister generators, which are considered to be flawless until now.
Next, we observe the limiting behavior of the generalized Khintchine constants. Let Tp(x)=1/xp(mod1) for 0 < x < 1 and Tp(0)=0. It is known that if p>p0=0.241485…,thenT_phasanabsolutelycontinuousergodicmeasure.Puta_n=\left\lfloor\left(1/T_p^{n-1}(x)\right)^p\right\rfloor,n ≥ 1,where\lfloor t \rflooristheintegerpartoft.Forarealnumberq,defineaveragesofa_nby◁수식삽입▷(원문을참조하세요)LetK_{p,q}:=lim_{n → ∞}K(p,q,n,x).Foralmosteveryx,weshowthat(i)K_{p,q} <∞ifandonlyifq <1/p,(ii)ifq=0,thenlim_{p → ∞}(log K_{p,q})/p = 1,(iii)ifq<0,thenlim_{p → ∞}log K_{p,q}/log{p} = 1/|q|,where‘log‘denotesthenaturallogarithm.ThelimitingbehaviorofK_{p,q}isinvestigatedaspdownarrowp_0$ with high precision computer simulations.한국과학기술원 : 수학전공