Meso and large scale models tend nowadays to be non-hydrostatic. Time step restrictions due to fast waves are alleviated by considering semi-implicit schemes (Thomas et al, 2003) or by use of the anelastic approximation (Meso-NH model, Lafore et al, 1998, or Clark, 1977 among others); in both cases an elliptic equation has to be solved. This equation is typically ill conditioned, due to the ran...

We present a nonstiff, fully adaptive mesh refinement-based method for the CahnHilliard equation. The method is based on a semi-implicit splitting, in which linear leading order terms are extracted and discretized implicitly, combined with a robust adaptive spatial discretization. The fully discretized equation is written as a system which is efficiently solved on composite adaptive grids using...

Sensitivity analysis is an important tool for describing power system dynamic behavior in response to parameter variations. It is a central component in preventive and corrective control applications. The existing approaches for sensitivity calculations, namely, finite-difference and forward sensitivity analysis, require a computational effort that increases linearly with the number of sensitiv...

A new Markov-based method for real time prediction of network transmission time delays is introduced. The method considers a Multi-Layer Perceptron (MLP) neural model for the transmission network, where the number of neurons in the input layer is minimized so that the required calculations are reduced and the method can be implemented in the real-time. For this purpose, the Markov process order...

A Lavrentiev type regularization technique for solving elliptic boundary control problems with pointwise state constraints is considered. The main concept behind this regularization is to look for controls in the range of the adjoint control-to-state mapping. After investigating the analysis of the method, a semismooth Newton method based on the optimality conditions is presented. The theoretic...

The reduction of backscatter radar cross section(RCS) in TE polarization for a rectangular cavity embedded in the ground plane is investigated in this paper. It is established by placing a thin, multilayered radar absorbing material(RAM) with possibly different permittivities at the bottom of the cavity. A minimization problem with respect to the backscatter RCS is formulated to determine the s...

In tomography it has been recognized that the finiteness of the frequency content of seismic data leads to interference effects in the process of medium reconstruction, that need to be accounted for. Various ways of looking at these effects in the framework of transmission tomography can be found in the literature. Here, we consider single-scattered body waves and develop from our earlier work ...

A method that employs a transfer matrix treatment combined with Monte Carlo sampling has been used to calculate the configurational free energies of folded and unfolded states of lattice models of proteins. The method is successfully applied to study the monomer-dimer equilibria in various coiled coils. For the short coiled coils, GCN4 leucine zipper, and its fragments, Fos and Jun, very good a...

Turnpike properties have been established long time ago in finite-dimensional optimal control problems arising in econometry. They refer to the fact that, under quite general assumptions, the optimal solutions of a given optimal control problem settled in large time consist approximately of three pieces, the first and the last of which being transient short-time arcs, and the middle piece being...

A time-spectral and adjoint-based optimization procedure that is particularly efficient for the analysis and shape design of helicopter rotors is developed. The time-spectral method is a fast and accurate algorithm to simulate periodic, unsteady flows by transforming them to a steady-state analysis using a Fourier spectral derivative temporal operator. An accompanying steady-state adjoint formu...