Evolutionary Algorithms for Query Op-timization in Distributed Database Sys-tems: A review

Evolutionary Algorithms are bio-inspired optimization problem-solving approaches that exploit principles of biological evolution. , such as natural selection and genetic inheritance. This review paper provides the application of evolutionary and swarms intelligence based query optimization strategies in Distributed Database Systems. The query optimization in a distributed environment is challenging task and hard problem. However, Evolutionary approaches are promising for the optimization problems. The problem of query optimization in a distributed database environment is one of the complex problems. There are several techniques which exist and are being used for query optimization in a distributed database. The intention of this research is to focus on how bio-inspired computational algorithms are used in a distributed database environment for query optimization. This paper provides working of bio-inspired computational algorithms in distributed database query optimization which includes genetic algorithms, ant colony algorithm, particle swarm optimization and Memetic Algorithms

Optical properties of ZnS and effect of doping with transition elements

By the help of density functional theory for a Cu doped ZnS compound the charge density, Fermi surface and electronic structure have been examined. We have used (FP-LAPW) method, to deal with interchange relationship potential for solving of kohn-sham equations. We apply generalized gradient approximation (GGA), local density approximation (LDA) and Engel-Vosko GGA (EVGGA). Cu doped ZnS compound confirms that nature of material is metallic and Fermi energy (EF) is obtained by the overlapping of Cu-p and Zn- d state. At Fermi energy (EF) calculated density of states is 51.932, 18.655 and 13.235 states/ev, and low-temperature electronic specific heat co-efficient (γ) is found to be 9.008mJ/mol-K2 for GGA, 3.236mJ/mol-K2 for LDA, and it was 2.295mJ/mol-K2 for EVGGA respectively. The thermal properties and optical constant were also discussed and calculated