Let G be an additive finite abelian group with exponent exp(G). Let S = g1 · . . . · gl be a sequence over G and k(S) = ord(g1)+· · ·+ord(gl) be its cross number. Let η(G) (resp. t(G)) be the smallest integer t such that every sequence of t elements (repetition allowed) from G contains a non-empty zero-sum subsequence T of length |T | ≤ exp(G) (resp. k(T ) ≤ 1). It is easy to see that t(G) ≥ η(...

Classification of blocks of subband samples according to their energy and variable bit allocation within the subsequent classes has demonstrated considerable gains in coding efficiency. The gains due to classification increase as smaller blocks are used; however, this increases the overheads for transmitting the classification information. In this paper, a quadtree based method is proposed. Thi...

The use of subband coding on image data is discussed. An overviev~ of siibbai~d coding is given. Advantages of subbanding for browsing and progressive resol~itiori ar-e presented. Implementations for lossless and lossy coding are discussed. Algorithn~ considerations and simple implementations of subband systems are given.

Heavy metal-based two-dimensional van der Waals materials have a large, coupled spin and valley Hall effect (SVHE) that has potential use in spintronics valleytronics. Optical measurements of the SVHE largely been performed below 30 K, understanding SVHE-induced spin/valley polarizations can be electrically generated is limited. Here, we study monolayer p-type tungsten diselenide (WSe2). Kerr r...