We have examined bursting processes observed in turbulent channel flow by d
irect numerical simulation of the incompressible Navier-Stokes equations in
a minimal flow unit. A traveling wave solution (TWS) is obtained by a shoo
ting method. The TWS corresponds to a saddle point in a two-dimensional pha
se space. A low-dimensional dynamics confined to the near-wall region is pr
oposed in terms of the TWS and its manifolds. The characteristics of the co
herent structures constituting the TWS are investigated dynamically and sta
tistically in detail. The dynamics well describes an elementary process of
intermittent turbulent regeneration in wall turbulence.