Shirley Halevy

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—We derive lower bounds on the capacity of certain two-dimensional (2-D) constraints by considering bounds on the entropy of measures induced by bit-stuffing encoders. A more detailed analysis of a previously proposed bit-stuffing encoder for ()-runlength-limited (RLL) constraints on the square lattice yields improved lower bounds on the capacity for all 2.(More)
We study a model of graph related formulae that we call the Constraint-Graph model. A constraint-graph is a labeled multi-graph (a graph where loops and parallel edges are allowed), where each edge e is labeled by a distinct Boolean variable and every vertex is associate with a Boolean function over the variables that label its adjacent edges. A Boolean(More)
We propose a new model for studying graph related problems that we call the orientation model. In this model, an undirected graph G is fixed, and the input is any possible edge orientation of G. A property is now a property of the directed graph that is obtained by a given orientation. The distance between two orientations is the number of edges that have(More)
A parallel constrained coding scheme is considered where p-blocks of raw data are encoded simultaneously into q tracks such that the contents of each track belong to a given constraint S. It is shown that as q increases, there are parallel block d e c o d a b l e encoders for S whose coding ratio, p=q, converges to the capacity of S. Examples are provided(More)