This paper presents two meta-heuristic algorithms to solve an extended portfolio selection model. The extended model is based on the Markowitz's Model, aiming to minimize investment risk in a specified level of return. In order to get the Markowitz model close to the real conditions, different constraints were embedded on the model which resulted in a discrete and non-convex solution space. ...

recommender systems (rs) provide personalized recommendation according to user need by analyzing behavior of users and gathering their information. one of the algorithms used in recommender systems is user-based collaborative filtering (cf) method. the idea is that if users have similar preferences in the past, they will probably have similar preferences in the future. the important part of col...

improving mechanical properties of composites based on strength-to-weight ratio has been gained much attention in various applications. having the most resistant and at the same time the lightest and the most economical structure is believed as an aim in these applications. these three factors are usually opposed to each other. so, applying optimization algorithms for improving mechanical prope...

background: mammography is the primary imaging technique for detection and diagnosis of breast cancer; however, the contrast of a mammogram image is often poor, especially for dense and glandular tissues. in these cases the radiologist may miss some diagnostically important microcalcifications. in order to improve diagnosis of cancer correctly, image enhancement technology is often used to enha...

Urban morphology, including buildings’ typology and their configuration, affects sky view factor and insolation, which are two of the most influential parameters in urban microclimate. These become even more important in extreme environmental conditions. In this research, challenge was to generate various rule based urban morphologies in a parametric environment. Then, to evaluate them based on...

A multi-objective heuristic particle swarm optimiser (MOHPSO) based on Pareto multi-objective theory is proposed to solve multi-objective optimality problems. The optimality objectives are the roof displacement and structure weight. Two types of structure are analysed in this paper, a truss structure and a framework structure. Performance-based seismic analysis, such as classical and modal push...

The main purpose of this research is portfolio optimization in Tehran securities exchange using the black hole algorithm and the Gravitational Research algorithm. We also propose an algorithm named Hybrid Algorithm which combines the two algorithms above to cover the weaknesses of these two algorithms. Finally we compare the results with the Markowitz model and choose the optimal algorithm.<br ...

All algorithms for impedance calculation use an analog-to-digital converter. The high accuracy of the impedance seen by a distance relay is an important factor in the correct isolation of the faulty part of power systems. To achieve this, a novel&#10technique based on third order interpolation is used in this paper. According to this technique, the times and the values of the obtained samples a...