Mobile robots with omni-directional wheels can generate instant omni-directional motion including lateral motion without any extra space for changing the direction of the body. So, they are capable of traveling in every direction under any orientation to approach their destinations even in narrow aisles or tight areas. Especially, if a construction tool is combined to the mobile robot, it can b...

In spatial reasoning, relationships between spatial entities play a major role. In image interpretation, computer vision and structural recognition, the management of imperfect information and of imprecision constitutes a key point. This calls for the framework of fuzzy sets, which exhibits nice features to represent spatial imprecision at different levels, imprecision in knowledge and knowledg...

This letter explores the effect of the directivity of a source on time reversal acoustic focusing of energy. A single loudspeaker produces an airborne focus of sound in a reverberation chamber and in a classroom. Individual foci are created at microphone positions that surround the loudspeaker. The primary axis of the loudspeaker is then rotated and experiments are repeated to average out the r...

We study eigenstates of chaotic billiards in the momentum representation and propose the radially integrated momentum distribution as useful measure to detect localization effects. For the momentum distribution, the radially integrated momentum distribution, and the angular integrated momentum distribution explicit formulae in terms of the normal derivative along the billiard boundary are deriv...