We present an approximate Jacobian approach for solving nonlinear, multiphase flow and transport problems in porous media. A backward Euler time discretization scheme is used; prior to spatial discretization with a lowest order mixed finite element method (MFEM). This results in a fully implicit nonlinear algebraic system of equations. Conventionally, an exact Jacobian construction is employed ...

We present several fast, practical linear-complexity scheduling algorithms that enable provision of various quality-of-service (QoS) guarantees in an input-queued switch with no speedup. Speciically, our algorithms provide per-virtual-circuit transmission rate and cell delay guarantees using a credit-based bandwidth reservation scheme. The novelties of our algorithms derive from judicious choic...

This paper aims at better possibilities to solve problems of exponential complexity. Our special focus is the combination of the computational power of four cores of a standard PC with better approaches in the application domain. As the main example we selected the unate covering problem which must be solved, among others, in the process of circuit synthesis and for graph-covering (domination) ...

The performance of the parallel implementation of the local meshless numerical method in solving system of coupled partial differential equations is explored. Presented numerical approach makes the computation convenient for parallel implementation using OpenMP based parallelization. The numerical experiments are performed on the de Vahl Davis natural convection case, with superlinear computati...

We introduce new proof systems for propositional logic, simple deduction Frege systems, general deduction Frege systems and nested deduction Frege systems, which augment Frege systems with variants of the deduction rule. We give upper bounds on the lengths of proofs in Frege proof systems compared to lengths in these new systems. As applications we give near-linear simulations of the propositio...

Generalized speedup is deened as parallel speed over sequential speed. In this paper the generalized speedup and its relation with other existing performance metrics, such as traditional speedup, eeciency, scalability, etc., are carefully studied. In terms of the introduced asymptotic speed, we show that the diierence between the generalized speedup and the traditional speedup lies in the deeni...