ABSTRACT

A first step of the theory of conditional random fields is developed, which will be a basis for stochastic interpolation of earthquake motions in seismic m onitoring of urban regions. F irst the significance of the development of regional seismic m onitoring systems is discussed w ith some practical examples. On this basis, further research needs tha t m otivate this study are made clear. Next, a preliminary discussion is made on stochastic interpolation of earthquake ground motion, which is a main issue for optim ization of a regional seismic m onitoring system. The main part of this paper presents a m ethod of sim ulation of conditional random fields involving determ inistic time functions, which is to be used as a m ajor tool for stochastic interpolation of earthquake motions. Closed form solutions are derived for conditional probability density functions for harmonic am­ plitudes and phase angles of interpolating motions conditioned by a given number of determ inistic tim e functions through coherence functions. Numerical examples for the analytical results as well as those for sim ulated interpolating motions are presented.