A c-ary Perfect Factor is a set of uniformly long cycles whose elements are drawn from a set of size c, in which every possible v-tuple of elements occurs exactly once. In the binary case, i.e. where c = 2, these perfect factors have previously been studied by Etzion, [2], who showed that the obvious necessary conditions for their existence are in fact sufficient. This result has recently been ...

Let G be a graph admitting a perfect matching. A cycle of even size C is central if G − C has a perfect matching. Given an orientation to G, an even cycle C is oddly oriented if along either direction of traversal around C, the number of edges of C with the direction as the same as the traversal direction is odd. An orientation of G is Pfaffian if every central cycle of G is oddly oriented. A g...

The complement of a graph G is denoted by G. χ(G) denotes the chromatic number and ω(G) the clique number of G. The cycles of odd length at least five are called odd holes and the complements of odd holes are called odd anti-holes. A graph G is called perfect if, for each induced subgraph G of G, χ(G) = ω(G). Classical examples of perfect graphs consist of bipartite graphs, chordal graphs and c...

In order to satisfy the needs of new applications in a multi-resolution environment the problem of object{ oriented coding has to be addressed. In this paper two main approaches are presented to tackle this problem. First, an algorithm for shape coding is presented. It is based on a chain coding algorithm where powerful modeling techniques are used to increase the compression ratio. Second, an ...

We show that the Folk theorem in Wen (1994) may not fully characterize the subgame-perfect equilibrium payo¤ set in a repeated game with unequal discounting, where a player’s equilibrium payo¤ could be strictly less than her e¤ective minimax payo¤ . Keywords: repeated games, e¤ective minimax values, heterogenous discounting JEL Classi…cation: C73

In this paper, we derive a capacity region for Gaussian fading multiple access degraded relay channel with partial channel state information (CSI) at the transmitters (CSIT) and perfect CSI at the receiver (CSIR). The achievable rate region obtained by Kramer-Wijngaarden is a special case of our region. Keywords-Gaussian fading channel; channel state information (CSI); discrete multiple access ...