Title of dissertation: EXPRESSIVENESS OF DEFINITIONS AND EFFICIENCY OF CONSTRUCTIONS IN COMPUTATIONAL CRYPTOGRAPHY David Omer Horvitz Doctor of Philosophy, 2007 Dissertation directed by: Professor Virgil Gligor Department of Electrical and Computer Eng. Professor Jonathan Katz Department of Computer Science The computational treatment of cryptography, and indeed any scientific treatment of a pr...

We consider two-phase flow problems, modelled by the Cahn-Hilliard equation. In our work, the nonlinear fourth-order equation is decomposed into a system of two second-order equations for the concentration and the chemical potential. We analyse solution methods based on an approximate two-by-two block factorization of the Jacobian of the nonlinear discrete problem. We propose a preconditioning ...

This paper introduces two algorithms (both actually are variants of a single algorithm)—the First price Upper Bound, FUB, and Second price Lower Bound, SeLB, algorithms—aimed at serving as subroutines in computationally efficient algorithms for combinatorial auctions. The type of combinatorial auctions treated in the paper are the once where bids are placed on one unit of one or more items at a...

The behavior of the number of partial problems T(A) which are decomposed in a branchand-bound algorithm A (T(A) may be taken as a measure for the computational efficiency of A) is investigated in a fairly general setting. The first result is that the mean number f(n) of T(A) when A is applied to problems of size n grows at least as fast as exponentially with n, under relatively mild conditions,...

The lattice Boltzmann method has evolved over the past decade to a common technique in the field of computational fluid dynamics. The basic principle of cellular-automata allows an easy simulation of discrete surfaces and implementation of different boundary conditions. To meet the numerical requirements of continuous surfaces the enhanced Bouzidi bounce-back with interpolation was implemented....

Analysis of metabolic networks typically begins with construction of the stoichiometry matrix, which characterizes the network topology. This matrix provides, via the balance equation, a description of the potential steady-state flow distribution. This paper begins with the observation that the balance equation depends only on the structure of linear redundancies in the network, and so can be s...