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...

Electromagnetism-like (EML) algorithm is a new evolutionary algorithm that bases on the electromagnetic attraction and repulsion among particles. It was originally proposed to solve optimization problems with bounded variables. Since its inception, many variants of the EML algorithm have been proposed in the literature. However, it remains unclear how to simulate the electromagnetic heuristics ...

Fujun LAN, Liang GAO Department of Industrial & Systems Engineering Huazhong University .of Science &Technology 430074, Wuhan, P. R. China Abstract: Layout optimization is a NP-hard and complex non-linear constrained optimization problem. To solve the problem, this paper proposes a Modified Electromagnetism-like Mechanism (MEM) algorithm. Firstly, the established local search method is modified...

this with the integration of distributed generation (dg) to meshed distribution systems, the operating time of the protective system becomes a major concern in order to avoid nuisance dg tripping. this paper proposes a new tripping characteristic for directional overcurrent relays (docrs) that can achieve a higher possible reduction of overall relays operating time in meshed distribution networ...

1. Abstract A well-known approach for solving constrained optimization problems is based on penalty functions. A penalty technique transforms the constrained problem into an unconstrained problem by penalizing the objective function when constraints are violated and then minimizing the penalty function using methods for unconstrained problems. In this paper, we analyze the implementation of a s...

The Electromagnetism-like (EM) algorithm is a populationbased stochastic global optimization algorithm that uses an attractionrepulsion mechanism to move sample points towards the optimal. In this paper, an implementation of the EM algorithm in the Matlab environment as a useful function for practitioners and for those who want to experiment a new global optimization solver is proposed. A set o...

Segmentation is one of the most important tasks in image processing. It consist in classify the pixels into two or more groups depending on their intensity levels and a threshold value. The quality of the segmentation depends on the method applied to select the threshold. The use of the classical implementations for multilevel thresholding is computationally expensive since they exhaustively se...

The traveling salesman problem with time windows (TSPTW) is a variant of the traveling salesman problem in which each customer should be visited within a given time window. In this paper, we propose an electromagnetism-like algorithm (EMA) that uses a new constraint handling technique to minimize the travel cost in TSPTW problems. The EMA utilizes the attraction-repulsion mechanism between char...