Abstract For airborne electronic countermeasures, a practical and feasible stealth trajectory with low observability significantly impacts mission success. However, for long-range large-scale optimization problems, the significant increase in state space size will affect feasibility optimality of problem solution. This paper proposes hybrid method to address above issues. First, A* (A-star) alg...

In this work, a method for estimating the space-dependent perfusion coefficient parameter in a 2D bioheat transfer model is presented. In the method, the bioheat transfer model is transformed into a time-dependent semidiscrete system of ordinary differential equations involving perfusion coefficient values as parameters, and the estimation problem is solved through a nonlinear least squares tec...

We present a formulation and implementation of MBller-Plesset perturbation theory in a pseudospectral framework. At the second-order level, the pseudospectral formulation is a formally a factor of N/n faster than conventional approaches, while the third order is formally faster by a factor of n, where Nis the number of atomic orbitals and n is the number of occupied orbitals. The accuracy of th...

In a previous paper we have presented a new method of imposing boundary conditions in the pseudospectral Chebyshev approximation of a scalar hyperbolic equation. The novel idea of the new method is to collocate the equation at the boundary points as well as in the inner grid points, using the boundary conditions as penalty terms. In this paper we extend the above boundary treatment to the case ...

Asymptotic dynamics of ordinary differential equations (ODEs) are commonly understood by looking at eigenvalues of a matrix, and transient dynamics can be bounded above and below by considering the corresponding pseudospectra. While asymptotics for other classes of differential equations have been studied using eigenvalues of a (nonlinear) matrix-valued function, there are no analogous pseudosp...

We present a stable algorithm for constructing derivative matrices with small norm for pseudospectral methods. In particular, we construct second derivative matrices that incorporate Dirichlet or Neumann boundary conditions on an interval and on the disk. By construction, the norm of these matrices grows at the optimal rate O(N) for N -by-N matrices, in contrast to standard pseudospectral const...

The real ε-pseudospectrum of a real matrix A consists of the eigenvalues of all real matrices that are ε-close in spectral norm to A. The real pseudospectral abscissa, which is the largest real part of these eigenvalues for a prescribed value ε, measures the structured robust stability of A w.r.t. real perturbations. In this report, we introduce a criss-cross type algorithm to compute the real ...

in this paper, the problem of optimal path following for a high speed planing boat is addressed. first, a nonlinear mathematical model of the boat’s dynamics is derived and then the serret-frenet frame is presented to facilitate the path following control design. to satisfy the constraints on the states and the input controls of the boat's nonlinear dynamics and minimize both the cross tracking...