Constrained multi-global optimization using a penalty stretched simulated annealing framework

This paper presents a new simulated annealing algorithm to solve constrained multi-global optimization problems. To compute all global solutions in a sequential manner, we combine the function stretching technique with the adaptive simulated annealing variant. Constraint-handling is carried out through a nondifferentiable penalty function. To benchmark our penalty stretched simulated annealing algorithm we solve a set of well-known problems. Our preliminary numerical results show that the algorithm is promising.This work has been partially supported by the FCT (Fundagao para a Ciencia e a Tecnologia), Portugal

Modeling of Hydrogen Storage Materials: A Reactive Force Field for NaH

Parameterization of a reactive force field for NaH is done using ab initio derived data. The parameterized force field(ReaxFFNaH) is used to study the dynamics governing hydrogen desorption in NaH. During the abstraction process of surface molecular hydrogen charge transfer is found to be well described by the parameterized force field. To gain more insight into the mechanism governing structural transformation of NaH during thermal decomposition a heating run in a molecular dynamics simulation is done. The result shows that a clear signature of hydrogen desorption is the fall in potential energy surface during heating

Overview on mixed integer nonlinear programming problems

Many optimization problems involve integer and continuous variables that can be modeled as mixed integer nonlinear programming (MINLP) problems. This has led to a wide range of applications, in particular in some engineering areas. Here, we provide a brief overview on MINLP, and present a simple idea for a future nonconvex MINLP solution technique.Fundação para a Ciência e a Tecnologia (FCT

Advanced step-point methods for the solution of initial value problems

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN009083 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Trigonometrically fitted predictor–corrector methods for IVPs with oscillating solutions

AbstractIn this paper we develop a trigonometrically fitted predictor–corrector (P–C) scheme, which is based on the well-known two-step second-order Adams–Bashforth method (as predictor) and on the third-order Adams–Moulton method (as corrector). Numerical experiments show that the new trigonometrically fitted P–C method is substantially more efficient than widely used methods for the numerical solution of initial-value problems (IVPs) with oscillating solutions