INTRODUCTION It is not clear whether flat lesions play a role in the pathogenesis of colorectal carcinoma. Flat lesions are being increasingly recognised with new colonoscopic techniques. MATERIALS AND METHODS A total of 10,939 consecutive colonoscopies were performed over a 9-year period. After bowel preparation with polyethylene glycol electrolyte lavage solution, high-resolution video colo...

many simulation algorithms (chemical reaction systems, differential systems arising from the modeling of transient behavior in the process industries and etc.) contain the numerical solution of systems of differential equations. for the efficient solution of the above mentioned problems, linear multistep methods or runge-kutta technique are used. for the simulation of chemical procedures the ra...

The present study introduces a new technique of homotopy perturbation method for the solution of systems of fractional partial differential equations. The proposed scheme is based on Laplace transform and new homotopy perturbation methods. The fractional derivatives are considered in Caputo sense. To illustrate the ability and reliability of the method some examples are provided. The results ob...

We present a new numerical scheme to solve efficiently scattering problems involving an elongated and flat heterogeneous dielectric material assumed be invariant along direction of space. The technique consists compressing the integral operators integro-differential formulation with so-called quantized tensor train (QTT) algorithm whose use is rather original in this context. show that it allow...

This paper presents a computational technique that called Tau-collocation method for the developed solution of non-linear integro-differential equations which involves a population model. To do this, the nonlinear integro-differential equations are transformed into a system of linear algebraic equations in matrix form without interpolation of non-poly-nomial terms of equations. Then, using coll...

‎In this paper‎, ‎a spectral Tau method for solving fractional Riccati‎ ‎differential equations is considered‎. ‎This technique describes‎ ‎converting of a given fractional Riccati differential equation to a‎ ‎system of nonlinear algebraic equations by using some simple‎ ‎matrices‎. ‎We use fractional derivatives in the Caputo form‎. ‎Convergence analysis of the proposed method is given an...

In this paper, we propose a method to approximate the solution of a linear Fredholm integro-differential equation by using the Chebyshev wavelet of the first kind as basis. For this purpose, we introduce the first Chebyshev operational matrix of integration. Chebyshev wavelet approximating method is then utilized to reduce the integro-differential equation to a system of algebraic equations. Il...

In this paper we describe Poisson structures defined on the space of Serret-Frenet equations of curves in a flat homogeneous space G/H where G is semisimple. These structures are defined via Poisson reduction from Poisson brackets on Lg∗, the space of Loops in g∗. We also give conditions on invariant geometric evolution of curves in G/H which guarantee that the evolution induced on the differen...

In this paper, differential transform method (DTM) is described and is applied to solve systems of nonlinear ordinary differential equations which is arising in HIV infections of cell. Intervals of validity of the solution will be extended by using Pade approximation. The results also will be compared with those results obtained by Runge-Kutta method. The technique is described and is illustrat...

Frequency-selective channels can be converted into a set of flat fading subchannels by employing Orthogonal Frequency Division Multiplexing (OFDM). Conventional differential encoding on each subchannel, however, suffers from loss of multipath diversity, and yields non-constant modulus transmissions, which causes undesirable non-linear effects. To mitigate these effects, we design a block differ...