The object of the present invention is to provide a remote assistant system for a foundry, i. A second plurality of negative-resistance elements are provided, each element having a first output coupled to a node on the first concentric ring and a second output coupled to a node on the second concentric ring. The collar has a convexly curved region having upper and lower ends spanning an included angle, with the upper end transitioning tangentially into the play region and a frustoconical skirt region flaring outwardly from the lower end of the curved region and transitioning into the outer edge area. A cushion made of an elastomeric material is retained in the outer case adjacent an end thereof and surrounds the riser assembly. The first color conversion unit converts an image signal corresponding to a reference color in the first color space into an image signal corresponding to the lattice points in the third color space.