Local kinematic properties of Population I (B5-F5)-type stars and galactic disk evolution.

Using a sample of (B5-F5) V type stars, located up to 250 pc, the basic parameters of the velocity ellipsoid have been derived. The observed distribution function of the peculiar velocities for different subsamples have been decomposed into a sum of three-dimensional Gaussians using the SEM algorithm (Celeux and Diebolt, 1985, 1986). Assuming that the stars are formed in bursts, the observed velocity distribution is explained as the sum of several independent (approximately spherical) distributions, each one corresponding to one generation of stars.