Global minima simulated annealing

Note The segmentation operation yields a near-optimal estimate x that may be used as initialization point for an optimization algoritlim that has to find out the global minimum of the criterion /(.). Because of its nonlinear nature, we prefer to minimize it by using a stochastic optimization algorithm (a version of the Simulated Annealing algorithm [3]). 

Finding the Global Energy Minimum Evolutionary Algorithms and Simulated Annealing... 

HyperChem has a facility for a more systematic approach to the global minimum than just choosing random starting points. This facility is associated with the idea of simulated annealing. 

Restrained MD (rMD) is followed by the use of MD in explicit solvent, i.e. the conformation as determined above is taken into a box containing many solvent molecules around the molecule. Subsequently, simulated annealing (SA) and energy minimizahon steps are performed to draw the molecule into the global energy minimum. An MD run (the so-called trajectory) over at least 150ps to Ins is followed and a mean structure is calculated from such a trajectory. The con-formahon must be stable under this condihon even when the experimental constraints are removed. 

The difficulty with this procedure is that simple refinement routines, such as simplex or least squares, lead only to the nearest minimum in the cost function which is unlikely to be the global minimum. The refinement procedure therefore has to be one that randomly samples different parts of configuration space so as to be able to reach different minima, ultimately selecting the global minimum. Two refinement methods have been proposed, simulated annealing and the genetic algorithm. 

Operations like pressure swing adsorption involve the condensation of the liquid in the porous medium. Several researchers developed predictive models of the configuration of liquid phase in the wet, unsaturated, porous media. The method developed by Silverstein and Fort (2000) is based on simulated annealing with random swapping of gas and liquid elements in the system to achieve a global energy minimum defined by... 

---