In this study, we perform a comprehensive theoretical evaluation of masking techniques for numerical microdata. The objective of this comparison is to establish the extent to which existing techniques can satisfy disclosure risk, data utility, ease of implementation, and ease of use requirements. This evaluation allows data providers to select from these techniques to account for the demands of...

Continuation techniques have been known to successfully describe bifurcation diagrams appearing in slow-fast systems with more than one slow variable (see eg. [12]). In this paper we investigate the usefulness of numerical continuation techniques dealing with some solved and some open problems in the study of planar singular perturbations. More precisely, we first verify known theoretical resul...

Optimization problems with partial differential equation (PDE) constraints arise in many science and engineering applications. Their robust and efficient solution present many mathematical challenges and requires a tight integration of properties and structures of the underlying problem, of fast numerical PDE solvers, and of numerical nonlinear optimization. This workshop brought together exper...

Our approach is to follow a methodical plan in the development and testing of a nonhydrostatic microscale modeling system that will leverage the existing COAMPS and new model prototypes. Our work on numerical methods will involve investigation of spatial and temporal discretization algorithms that are superior to the current generation leap-frog, second-order accurate numerical techniques prese...

A study has been undertaken to develop techniques for assessing baseball bat durability and performance. Experimental investigations were conducted by constructing a testing device to simulate the ball-bat interaction occurring in play. A sensitivity study of the machine’s inertia and forces on the bat were found to have a small effect on hit ball speed, and a much larger effect on bat stress. ...

 Flash Boiling atomization is one of the most effective means of generating a fine and narrow-dispersed spray. Unless its complexity its potential has not been fully realized. In This Paper, a three dimensional chamber has been modeled with a straight fuel injector. Effect of Flash Boiling has been investigated by computational fluid dynamics (CFD) techniques. A finite volume approach with the ...

In the present study, Computational Fluid Dynamics (CFD) techniques and Artificial Neural Networks (ANN) are used to predict the pressure drop value (Δp ) of Al2O3-water nanofluid in flat tubes. Δp  is predicted taking into account five input variables: tube flattening (H), inlet volumetric flow rate (Qi  ), wall heat flux (qnw  ), nanoparticle volume fraction (Φ) and nanoparticle diameter (dp ...

In this paper we discuss some recently published preconditioners for the incompressible Navier-Stokes equations. In combination with Krylov subspace methods, they give a fast convergence for the solution of the Navier -Stokes equations. With the help of numerical experiments, we report some new findings regarding the convergence of these preconditioners. Besides that, a renumbering scheme for d...

Investigation of combustion instabilities in gas turbine combustors require the knowledge of flame transfer functions. Those can be obtained by experimental measurement or by Large Eddy Simulations (LES). Since calculations are usually limited to a portion of the whole combustor, boundary conditions are of crucial importance. It is common practice to inject acoustic perturbations for the flame ...

Numerical operations on and among rational matrices are traditionally handled by direct manipulation with their scalar entries. A new numerically attractive alternative is proposed here that is based on rational matrix interpolation. The procedure begins with evaluation of rational matrices in several complex points. Then all the required operations are performed consecutively on constant matri...