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In this paper, the performance of the variables: makespan time, defective fraction due to operator fatigue and direct labor cost, in a job shop manufacturing system is presented. Two methods are compared; the first one blends elements from VEGA and MOGA algorithms (V&M), while the second one corresponds to a weighted sums method (WSM). Applying these methodologies, it was found that the method V&M has a better performance than the WSM. Comparing he variable makespan time (in hours) the first is better by 7.0 %; comparing the variable makespan time (in weeks) by 6.7 %; and comparing the variable defective fraction by 1.4 %. Regarding the variable labor costs, both methods have the same performance. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to predict functional states in complex processes from the estimation of fuzzy membership degrees. The proposal integrates a static measure, such as the result of a fuzzy classifier trained with historical process data, and an estimation algorithm based on Markov theory for discrete events. The proposal, which can be integrated to the monitoring of complex systems, provides two stages: an off-line training stage to define the fuzzy classifier and the estimator; and an online stage where the classification of the current process situation and the estimation of the next functional state are performed. The proposal for the estimation of functional states allows using any fuzzy clustering method that provides the information required by the methodology. The proposed methodology was successfully tested on a monitoring system for a power transmission line and in the monitoring of a boiler system. [ABSTRACT FROM AUTHOR]

This paper presents the design of an expert controller applied to voltage level control in a power system. The use of pilot node concept allows to keep stable the list of controllers against topological changes in the network. To achieve the optimal voltage profile, the Alberta Electric System Operator regulations are used. The controller validation is performed by simulating a case library and the solution is compared with results provided by an optimal power flow and a genetic based algorithm. The main advantage of the propose model is the unified treatment of the voltage profile and the reactive dispatch without the need of a two-step algorithm. The proposed controller is suitable for online real-time applications and it is flexible when dealing with problems that present a complex analytical formulation. [ABSTRACT FROM AUTHOR]

This paper determines the tractor stock and aggregate adoption growth of agricultural tractors in Chile. A logistic model was applied to determine the adoption growth and the adoption speed of agricultural tractors. Model parameters were determined by a non-linear algorithm. The tractor stock balance and the tractorization curve were used to estimate variation rate between t and t-1. This variation was associated with the introduction of tractors and those units removed from the stock. The logistic model showed a significant adjustment level and allowed estimating the rate of adoption and the adoption saturation level. It is concluded that the methodology can be applied to study technological adoption in other regions and other countries. [ABSTRACT FROM AUTHOR]

The aim of the work presented in this paper was to reduce makespan time and idle time, and to increase machine utilization, in Job Shop-Open Shop environment, using a new methodology based on evolutionary algorithms. The study was done in an enterprise of the metal-mechanics sector. The proposed methodology is easy to implement and apply and the results are highly consistent, as shown by a variance analysis. The methodology allows reducing the total processing time by 33% and idle time by 51% with 99% approximation with respect to the optimum solution. [ABSTRACT FROM AUTHOR]

This paper presents the application of an evolutionary algorithm using Matlab to obtain the optimum main angles of the cutting geometry of a machining tool. The optimization method considered the non linear model of Kaldor and Venuvinod. Different algorithm configurations were tested using data obtained from the literature. Several simulations were carried out to validate the performance of the algorithm and to show the usefulness of the method employed. It is concluded that that the proposed approach shows to be stable and coherent in the results for the cases studied. [ABSTRACT FROM AUTHOR]