We present a domain decomposition technical for computing the quantum transport phenomena in complex nano-structures. In regular sub-domains, the subband decomposition method is applied, while the finite difference method is used on small irregular sub-domains where the subband decomposition is not applicable. This new approach preserves the efficiency of the original subband decomposition meth...

We address the problem of blind multiuser multichannel identification in a Spatial Division Multiple Access (S.D.M.A.) context. Using a stochastic model for the input symbols and only second order statistics, we develop a simple algorithm, based on the Generalized Schur algorithm to apply LDU decomposition of the covariance matrix of the received data. We show that this method leads to identifi...

Operator-counting is a recently developed framework for analysing and integrating many state-ofthe-art heuristics for planning using Linear Programming. In cost-optimal planning only the objective value of these heuristics is traditionally used to guide the search. However the primal solution, i.e. the operator counts, contains useful information. We exploit this information using a SATbased ap...

In this paper we prove that Neville elimination can be matricially described by elementary matrices. A PLU-factorization is obtained for any n×m matrix, where P is a permutation matrix, L is a lower triangular matrix (product of bidiagonal factors) and U is an upper triangular matrix. This result generalizes the Neville factorization usually applied to characterize the totally positive matrices...

In a wide range of practical problems correlation matrices are formed in such a way that, while symmetry and a unit diagonal are assured, they may lack semidefiniteness. We derive a variety of new upper bounds for the distance from an arbitrary symmetric matrix to the nearest correlation matrix. The bounds are of two main classes: those based on the eigensystem and those based on a modified Cho...

In this paper we present a differential semantics of Lazy AR Propagation (LARP) in discrete Bayesian networks. We describe how both single and multi dimensional partial derivatives of the evidence may easily be calculated from a junction tree in LARP equilibrium. We show that the simplicity of the calculations stems from the nature of LARP. Based on the differential semantics we describe how va...

In this paper, we are concerned with a matrix equation Ax = b where A is an n× n real matrix and x and b are n-vectors. Assume that an approximate solution e x is given together with an approximate LU decomposition. We will present fast algorithms for proving nonsingularity of A and for calculating rigorous error bounds for ‖A−1b − e x‖∞. The emphasis is on rigour of the bounds. The purpose of ...

In this study, we extend the Karhunen–Loève moment equation (KLME) approach, an approach based on KL decomposition, to efficiently and accurately quantify uncertainty for flow in nonstationary heterogeneous porous media that include a number of zones with different statistics of the hydraulic conductivity. We first decompose the log hydraulic conductivity Y = lnKs for each zone by the KL decomp...