In this paper we design a new practical computer algorithm based on chaotic map lattices which allows direct encryption and decryption of color digital images. The basic idea is to convert, pixel by pixel, the image color to logistic chaotic maps one-way coupled by initial conditions. After small numbers of iterations and cycles, the image becomes indistinguishable due to inherent properties of...

In this paper we investigate some fully coupled parallel two-grid Lagrange-Newton-Krylov-Schwarz (LNKSz) algorithms for the suboptimal distributed control of unsteady incompressible flows governed by the Navier-Stokes equations. The algorithms include two major parts: a two-grid Newton method for the nonlinear part of the problem and a two-level Schwarz preconditioner for the linear part of the...

A fast parallel iterative method is proposed for the solution of linear equations arizing from Finite Element discretization of the time harmonic coupled fluid-solid systems in fluid pressure and solid displacement formulation. The fluid and the solid domains are decomposed into nonoverlapping subdomains. Continuity of the solution is enforced by Lagrange multipliers. The system is augmented by...

in this paper, we present two new families of third-order and fourth-order methods for finding multiple roots of nonlinear equations. each of them requires one evaluation of the function and two of its first derivative per iteration. several numerical examples are given to illustrate the performance of the presented methods.

This article presents a comprehensive comparative study between two nonlinear solvers for the hybrid analytical modeling (HAM) formulation. The Newton-Raphson method (NRM) and fixed-point (FPM) are compared in terms of their convergence rate, computational time, accuracy. A new HAM formulation using loop-based magnetic equivalent circuit (MEC) instead node-based one is proposed to improve condi...

OBJECTIVES To determine the efficacy and optimal application parameters of circumferential compression to reduce external rotation-type pelvic fractures. DESIGN Biomechanical investigation on human cadaveric specimens. SETTING Biomechanics laboratory. INTERVENTION Partially stable and unstable external rotation injuries of the pelvic ring (OTA classification 61-B1 and 61-C1) were created ...

PURPOSE This study was undertaken to evaluate the insertion forces utilized during simulated placement of a urethral catheter by healthcare individuals with a variety of catheter experience. MATERIALS AND METHODS A 21F urethral catheter was mounted to a metal spring. Participants were asked to press the tubing spring against a force gauge and stop when they met a level of resistance that woul...