CAJ | 학술논문

粘弹性参数变得越来越重要,其反演算法也逐渐成为众多研究者的研究热点.而遗传算法是一种随机、自适应、启发式的算法,具有很好的鲁棒性和全局收敛性,本文基于VSP直达波方程,引入了遗传算法来进行粘弹参数反演,首先将频率域直达波方程表示为复速度的函数,然后通过遗传算法反演出复速度.而复速度和品质因子又是复速度的函数,从而便可很容易的得出.但若直接反演复速度,反演参数太多,不容易实现,所以又将复速度表示成参数C0和C∞的函数,以减少反演参数数量.最后给出了理论模型实验,以证明该算法的有效性.
점탄성삼수변득월래월중요,기반연산법야축점성위음다연구자적연구열점.이유전산법시일충수궤、자괄응、계발식적산법,구유흔호적로봉성화전국수렴성,본문기우VSP직체파방정,인입료유전산법래진행점탄삼수반연,수선장빈솔역직체파방정표시위복속도적함수,연후통과유전산법반연출복속도.이복속도화품질인자우시복속도적함수,종이편가흔용역적득출.단약직접반연복속도,반연삼수태다,불용역실현,소이우장복속도표시성삼수C0화C∞적함수,이감소반연삼수수량.최후급출료이론모형실험,이증명해산법적유효성.
Viscoelastic parameters are becoming more important and their inversion algorithms are studied by many researchers. Genetic algorithms are random, self-adaptive,robust, and heuristic with global search and convergence abilities. Based on the direct VSP wave equation, a genetic algorithm (GA) is introduced to determine the viscoelastic parameters. First, the direct wave equation in frequency is expressed as a function of complex velocity and then the complex velocities estimated by GA inversion. Since the phase velocity and Q-factor both are functions of complex velocity, their values can be computed easily.However, there are so many complex velocities that it is difficult to invert them directly. They can be rewritten as a function of c0 and c∞ to reduce the number of parameters during the inversion process. Finally, a theoretical model experiment proves that our algorithm is exact and effective.