In this paper we extend the homogenization method to the optimization of the position of fuel assemblies in a nuclear reactor core. For this type of problem the state equation is a system of diffusion equations for the neutron flux. Homogenization theory allows to relax a truly discrete optimization problem into a continuous and well-posed optimization problem. The latter one is solved by using...

We construct and analyze a discrete fitness landscape called metabolic adjustment landscape, from sub-networks covered by different productive flux distributions of a metabolic network. The topological structure of this landscape, i.e., the local minima and saddle points, can be compactly represented as a hierarchical structure called barrier tree. The switching from one local optimal flux patt...

Flux balance analysis (FBA) is an effective tool in the analysis of metabolic network. It can predict the flux distribution of engineered cells, whereas the accurate prediction depends on the reasonable objective function. In this work, we propose two nonlinear bilevel programming models on anaerobic glycerol metabolism in Klebsiella pneumoniae (K. pneumoniae) for 1,3-propanediol (1,3-PD) produ...

We study zero temperature fluctuations of charge flow in a metallic loop induced by time dependent magnetic flux, and solve for the optimal way of varying flux in order to minimize noise. Optimal time dependence of the flux is a sum of “solitons,” each corresponding to quantized flux change. Minimal noise coincides with that for the binomial distribution with the number of attempts equal to the...

background: in neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials.   objective: the purpose of this study is to evaluate dose distribution in the presence of  10 b ,  157 gd  and  33 s  ne...

In the present work, a hybrid approach has been proposed for optimal placement of multiple DGs of multiple types. The analytical approaches may not be appropriate for optimal placements of multiple DGs alone. In this work, hybridization of analytical method and heuristic search for the optimal placement of multiple DGs in power distribution network for reduction of power loss has been proposed....