The focus of this paper is to improve the level of security and secrecy provided by the chaotic map based image encryption.An encryption algorithm based on the Logistic and the Henon maps is proposed. The algorithm uses chaotic iteration to generate the encryption keys, and then carries out the XOR and cyclic shift operations on the plain text to change the values of image pixels. Chaotic Map L...

optimizing the database queries is one of hard research problems. exhaustive search techniques like dynamic programming is suitable for queries with a few relations, but by increasing the number of relations in query, much use of memory and processing is needed, and the use of these methods is not suitable, so we have to use random and evolutionary methods. the use of evolutionary methods, beca...

the main purpose of design in civil engineering is to establish a project which has the most versatility on the expected needs and existing conditions. through optimization this is equivalent to determination of a group of design variables that cause minimizing the object function versus imposed loads, restraints and predetermined parameters. in this research, genetic algorithm method is used t...

replacement of a tractor is an influential factor affecting timely farm operation. the accurate prediction of repair and maintenance costs is essential to selection of a replacement model. this study used empirical data for 60 two-wheel drive (2wd) tractors from astan ghods-e razavi agroindustry. the types and numbers of tractors used were the massey ferguson 285 (17), fiat (10), john deere 314...

application of either protein or carbohydrate-based products as fat replacers in low fat ice-creams can improve the properties of these products. however, the type and level of fat and fat replacer utilized are affected by such different parameters as functional ones, namely: viscosity and overrun, hardness and melting rate, nutritional properties (calories) as well as the price of the final pr...

with the growth in customers’ demand diversification, mixed-model u-lines (mmul) have acquired increasing importance in the area of assembly systems. there are generally two different approaches in the literature for balancing such systems. some researchers believe that since the types of models can be very diverse, a balancing approach without simultaneously sequencing of models will not yield...

This paper presents a parallel genetic algorithm for three dimensional bin packing with heterogeneous bins using Hadoop Map-Reduce framework. The most common three dimensional bin packing problem which packs given set of boxes into minimum number of equal sized bins is proven to be NP Hard. The variation of three dimensional bin packing problem that allows heterogeneous bin sizes and rotation o...

In this paper a hybrid algorithm based on exploration power of the Genetic algorithms and exploitation capability of Nelder Mead simplex is presented for global optimization of multi-variable functions. Some modifications are imposed on genetic algorithm to improve its capability and efficiency while being hybridized with Simplex method. Benchmark test examples of structural optimization with a...

-An improved genetic algorithm applies the optimization procedures of protein folding through defining a new move set in lattice model. The new move set including rotation and mirror reflection is suitable for use in protein folding simulation. Through folding simulation on a simple lattice model it is found that the new move set is dramatically superior to that of the commonly used move set.