In this paper, we present an improvement of the Grouping Genetic Algorithm (GGA) which has been described in [6]. The algorithm has been enhanced with local optimisation techniques which are based on problem-specific heuristics and incorporated into the genetic operators. First experiments on well-known benchmark problems on examination timetabling show that the new hybrid algorithm (HGGA) prod...

dosulepin and doxepin are tricyclic antidepressants. the molecular geometries, harmonic vibrational frequencies, quantum chemical parameters and thermodynamic properties of dosulepin and doxepin were calculated by generalized gradient approximation methods developed by perdew and wang (gga-pw91) and becke-lee-yang-parr (gga-blyp) in the gas phase and solution media. the local reactivity of thes...

Thermodynamic properties of β-HMX crystal are investigated using the quasi-harmonic approximation and density functional theory within the local density approximation (LDA), generalized gradient approximation (GGA), and GGA + empirical van der Waals (vdW) correction. It is found that GGA well describes the thermal expansion coefficient and heat capacity but fails to produce correct bulk modulus...

The thermal properties of bulk copper are investigated by performing ab initio DFT and DFPT calculations and using the quasiharmonic approximation for the free energy. Using both the LDA and the GGA for the exchangecorrelation potential, we compute the temperature dependence of the lattice constant, coefficient of thermal expansion, bulk modulus, pressure derivative of the bulk modulus, phonon ...

Surface energies of some simple metals (Be, Al, Mg, Li, and Na) were calculated within density functional theory. Various approximations for the exchange and correlation were tested: local density approximation (LDA), generalized gradient approximations (GGA), and meta–generalized gradient approximation (MGGA). We used the Crystal98 code to calculate slabs with one to 10 layers using both all-e...

The local-spin-density approximation and the generalized-gradient approximation ~GGA! are used to perform density-functional total-energy calculations at zero temperature for Fe3Al in the ordered D03 and L12 structures. Our calculations show that commonly used GGA functionals fail to predict the experimentally stable D03 structure as the one with the lower total energy. This qualitative discrep...

In the present investigation, the results of extensive benchmarking study of density functional theory (DFT) methods on some catalytically important metal dimers have been reported. The calculations were carried out on Al2, Ti2, V2, Cr2, Mn2, Fe2, Co2, Ni2, Cu2, and Zn2 using DFT functionals such as GGA, meta GGA, hybrid meta GGA along with recently developed Minnesota functionals. The bond len...

The Grouping Genetic Algorithm (GGA) is a Genetic Algorithm heavily modified to suit the structure of grouping problems. Those are the problems where the aim is to find a good partition of a set, or to group together the members of the set. The Bin Packing Problem (BPP) is a well known NP-hard grouping problem items of various sizes have to be grouped inside bins of fixed capacity. On the other...

This paper describes the development and application of a modified Grouping Genetic Algorithm (GGA) used to identify sets of optimal ambulance locations. The GGA was modified to consider a special case with only two groups, and the reproduction and mutation schemes were modified to operate more efficiently. It was applied to a case study locating ambulances from a fixed set of alternative locat...