An earlier paper [J. Opt. Soc. Am. A 1, 775 (1984)] described a general ideal discriminator (a Stimuli-Defined-Exactly observer) whose sensitivity is limited only by the initial sequence of mechanisms in the visual system--the optics of the eye, the receptor lattice, receptor optics, and photopigment spectral sensitivities. In the present paper, further properties of the model are derived, and ...

Let F be a binary clutter. We prove that if F is non-ideal, then either F or its blocker b(F) has one of L7,O5,LC7 as a minor. L7 is the non-ideal clutter of the lines of the Fano plane, O5 is the non-ideal clutter of odd circuits of the complete graph K5, and the two-point Fano LC7 is the ideal clutter whose sets are the lines, and their complements, of the Fano plane that contain exactly one ...

OBJECTIVE To determine the entry for the dorsal pedicular screw in relation to the notch present at the junction of base of the lateral margin of superior articular process with superior border of transverse process in dorsal spine. The advantage of this technique is a constant and easily identifiable entry point which does not involve partial resection of the inferior facet, thus maintaining s...

In this paper we establish the correspondence between Bogoyavlenskij symmetries [1, 2] of the MHD equilibrium equations and Lie point transformations of these equations. We show that certain non-trivial Lie point transformations (that are obtained by direct application of Lie method) are equivalent to Bogoyavlenskij symmetries. PACS Codes: 05.45.-a , 02.30.Jr, 02.90.+p, 52.30.Cv.