We present an alternative approach to higher derived homotopy structures induced by the ’basic perturbation lemma’. This approach is motivated by physical considerations and makes use of operads and their representations. As an application we prove that the BVF-complex controls the formal deformations of coisotropic submanifolds – at least locally or under assumptions on the topology of the coi...

in this work, by employing the krasnosel'skii fixed point theorem, we study the existence of positive solutions of a three-point boundary value problem for the following fourth-order differential equation begin{eqnarray*} left { begin{array}{ll} u^{(4)}(t) -f(t,u(t),u^{prime prime }(t))=0 hspace{1cm} 0 leq t leq 1, & u(0) = u(1)=0, hspace{1cm} alpha u^{prime prime }(0) - beta u^{prime prime...

In this paper, we investigate a singular perturbation problem including a fourth order O.D.E. with general linear boundary conditions. Firstly, we obtain the necessary conditions of solution of O.D.E. by making use of fundamental solution, then by compatibility of these conditions with boundary conditions, we determine that, for given perturbation problem, whether boundary layer is formed or not.

This paper presents the bending analysis of annular plates by the indirect Trefftz boundary approach. The formulation for thin and thick plates is based on the Kirchhoff plate theory and the Reissner plate theory. The governing equations are therefore a fourth-order boundary value problem and a sixth-order boundary value problem, respectively. The Trefftz method employs the complete set of solu...

This study develops a fuzzy sliding mode controller (FSMC) based on a variable boundary layer. A fuzzy inference mechanism is used to on-line tune the thickness of the boundary layers of the controller. Minimum rule base has been used for the fuzzy inference system which results in low calculation effort. The aim of this paper is to design a controller which will eliminate the chattering of FSM...

The three–dimensional incompressible viscous Boussinesq equations, under the assumption of hydrostatic balance, govern the large scale dynamics of atmospheric and oceanic motion, and are commonly called the primitive equations. To overcome the turbulence mixing a partial vertical diffusion is usually added to the temperature advection (or density stratification) equation. In this paper we prove...

We propose a novel unified particle representation for fluids and solid boundaries in Implicit Incompressible SPH (IISPH). In contrast to existing particle representations, the proposed concept does not require a separate processing of fluid and boundary particles. On one hand, this results in a simplified solver implementation with improved efficiency. On the other hand, the unified fluid and ...

We will consider the inverse conductivity problem or Calderón problem [11] in three dimensions (and higher). The fundamental paper is the work of Sylvester and Uhlmann [23] which gives global uniqueness in the inverse conductivity problem in three dimensions. In this problem we want to find a coefficient in an elliptic differential operator The first step will be to recover the coefficient at t...