A direct method called fixation is introduced for solving the general motion vision problem, arbitrary motion relative to an arbitrary environment. This method results in a linear constraint equation which explicitly expresses the rotational velocity in terms of the translational velocity. The combination of this constraint equation with the Brightness-Change Constraint Equation solves the gene...

A two-layer model for 1D vertical unsaturated flow based on the hypothesis of a sharp wetting front is presented. The model further assumes a uniform pore pressure throughout the wetting zone at any given time during the infiltration and redistribution processes. These assumptions allow to reduce the theoretical Richards equation to an ordinary differential equation that can track average soil ...