thermal contact conductance (tcc) between an exhaust valve and its seat is one of the important parameters to be estimated in an internal combustion engine. an experimental study presented here to acquire temperature in some interior points to be used as inputs to an inverse analysis. an actual exhaust valve and its seat are utilized in a designed and constructed setup. conjugate gradient metho...

In many applications, such as the heat conduction and hydrology, there is a need to recover the (possibly discontinuous) diffusion coefficient a from boundary measurements of solutions of a parabolic equation. The complete inverse problem is ill posed and nonlinear, so numerical solution is quite difficult, and we linearize the problem around constant a. We study and solve numerically the linea...

We consider the inverse problem of recovery of an initial condition of a hyperbolic PDE. This problem is also called sometimes “thermoacoustic tomography”. In the past publications both stability estimates and convergent numerical methods for this problem were obtained only under some restrictive conditions imposed on the principal part of the elliptic operator. In this paper logarithmic stabil...

Let G be a group. We will call G a group with Cayley data if we are given all three of the following: the underlying set G; the collection of all Cayley sets of G; and for each Cayley subset S of G, the corresponding Cayley graph Cay(G,S). Is it then possible, from the Cayley data, to reconstruct the binary operation of the group? Is it possible to determine the isomorphism class of the group? ...

In this paper, a stability result on an inverse source scattering problem is shown for Helmholtz equation in multi-layered medium. The estimate consists of Lipschitz term low frequencies and logarithmically unstable high frequencies, based the Green's function problem. Moreover, logarithmic decreases as frequency grows, which indicates almost Lipschitz. This demonstrates that increasing problem...

Recently, we demonstrated that humans can learn to make accurate movements in an unstable environment by controlling magnitude, shape, and orientation of the endpoint impedance. Although previous studies of human motor learning suggest that the brain acquires an inverse dynamics model of the novel environment, it is not known whether this control mechanism is operative in unstable environments....

The main purpose of this paper is to solve an inverse random differential equation problem using evolutionary algorithms. Particle Swarm Algorithm and Genetic Algorithm are two algorithms that are used in this paper. In this paper, we solve the inverse problem by solving the inverse random differential equation using Crank-Nicholson's method. Then, using the particle swarm optimization algorith...