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Vienna, VA, United States

Studies in Informatics and Control | Year: 2015

The Assembly Line Balancing problem is an industrial optimization problem of considerable importance in lean systems. It has been extensively studied in literature through classical optimization methods. However, conventional computing paradigms have not proved practical utility for complex problems. Metaheuristic solutions such as "Tabu Search", "Simulated Annealing", "Genetic Algorithms", "Evolutionary Programming", "Ant Colony", "Particle Swarm Optimization" were a preoccupation mainly for the last two decades. This paper presents a model of a multi-objective Assembly Line Balancing problem and a solution approach based on Particle Swarm Optimization (PSO) with a fuzzy controller for tuning inertia weight. This prevents the premature convergence and, in addition, the algorithm demonstrates improved search features. For the considered test instance, the algorithm obtains a better result compared to the results reported in the literature, regarding the number of stations actually used, the line efficiency, the total unused time, the variation in charging stations and the uniformity index of the line. © ICI Bucharest 2010 - 2015.

Haller E.A.,CEL-SCI
Annals of the University of Craiova, Mathematics and Computer Science Series | Year: 2011

In order to analyze, the aerospatial images must pass through a series of trans- formations. Interpretation can be done by a human or by a computer. Image enhancement is made for interpretation and the interpretation can be done by a human or by a computer. The color interpolation or color demosaicing technique is used to recover missing color components in a RGB color system. These techniques are classified in nonadaptive and adaptive histogram equalization algorithms. We will analyze and compare some of the nonadaptive and adaptive algorithms that are successfully used in processing of large image files, such as aerospatial images.

The paper presents the interaction between the combustible mass and the tailings in the combustion process and its effect on reducing caloric power of the mass fuel. It also discusses problems regarding the influence of tailings on analytical determinations carried out on the combustible mass. Research has shown that a high content of tailings (over 25%) makes fuel inefficient, and it can only be used when com bined with their organic and inorganic mass. As preparation of fuel is expensive, and very often uneconomic, we suggest that it be operated so as the content of tailings be the one required by users.

Axinte T.,CEL-SCI
Advanced Materials Research | Year: 2014

Rail-wheel contact problems have been analyzed by the use of the three-dimensional finite element models. Based on these models, the paper presents a study regarding the applicability of the Hertz contact to rail-wheel contact problems. Beside a standard rail, the study also considers a crane rail and a switching component. The bodies of the contact problem are the standard rail UIC60 and the standard wheel UICORE. The maximum contact pressure which the material can support in the elastic range in steady state conditions is known as the 'shakedown limit'. With an operating contact pressure below the shakedown limit the rail would be expected to remain elastic a long period of its lifecycle. However, examination of rail cross-sections shows severe plastic deformation in a sub-surface layer of a few tens of microns thickness; the contact patch size is in tens of millimeters. Three-dimensional elastic-plastic rolling contact stress analysis was conducted incorporating elastic and plastic shakedown concepts. The Hertzian distribution was assumed for the normal surface contact load over a circular contact area. The tangential forces in both the rolling and lateral directions were considered and were assumed to be proportional to the Hertzian pressure. The elastic and plastic shakedown limits obtained for the three-dimensional contact problem revealed the role of both longitudinal and lateral shear traction on the shakedown results. An advanced cyclic plasticity model was implemented into a finite element code via the material subroutine. Finite element simulations were conducted in order to study the influences of the tangential surface forces in the two shear directions on residual stresses and residual strains. The Hertz theory is restricted to frictionless surfaces and perfectly elastic solids, but it is the best method for determining deformations and stress from pitch of contact. Form change due to wear and plastic deformation of a rail can reduce the service life of a track. The purpose of this investigation was to study the development of these damage mechanisms on new and three years old rails in a commuter track over a period of two years. © (2014) Trans Tech Publications, Switzerland.

Deleanu D.,CEL-SCI
Recent Researches in Computational Techniques, Non-Linear Systems and Control - Proc. of the 13th WSEAS Int. Conf. on MAMECTIS'11, NOLASC'11, CONTROL'11, WAMUS'11 | Year: 2011

In the present paper our intention was to verify if the Dynamic Lyapunov Indicator (DLI), proposed recently by Saha and Budhraja as a new tool for distinguishing between ordered and chaotic orbits, gives correct conclusions when is applied to discrete dynamical systems. With this end in view, the behavior of the 2D Lozi map, the 2-D predator prey map and the 3-D Lorentz BD map is analyzed with the help of DLI and, for comparison, with the help of Fast Lyapunov Indicator (FLI), a consecrated tool in chaos theory. Results obtained seem to qualify the DLI as a new indicator of chaos, at least for discrete dynamical systems.

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