A Hybrid Metaheuristic-Based Approach for the Aerodynamic Optimization of Small Hybrid Wind Turbine Rotors

This work presents a novel framework for the aerodynamic design and optimization of blades for small horizontal axis wind turbines (WT). The framework is based on a state-of-the-art blade element momentum model, which is complemented with the XFOIL 6.96 software in order to provide an estimate of the sectional blade aerodynamics. The framework considers an innovative nested-hybrid solution procedure based on two metaheuristics, the virtual gene genetic algorithm and the simulated annealing algorithm, to provide a near-optimal solution to the problem. The objective of the study is to maximize the aerodynamic efficiency of small WT (SWT) rotors for a wide range of operational conditions. The design variables are (1) the airfoil shape at the different blade span positions and the radial variation of the geometrical variables of (2) chord length, (3) twist angle, and (4) thickness along the blade span. A wind tunnel validation study of optimized rotors based on the NACA 4-digit airfoil series is presented. Based on the experimental data, improvements in terms of the aerodynamic efficiency, the cut-in wind speed, and the amount of material used during the manufacturing process were achieved. Recommendations for the aerodynamic design of SWT rotors are provided based on field experience

A negative pressure device for the treatment of diabetic foot.

Background: We studied the use of a negative pressure device designed by one of the authors (JATB) to determine if it shortens healing time and lowers the amputation level in patients with diabetic foot. Methods: Twenty-two patients in two randomized groups were studied. The characteristics of the ulcer according to the Wagner classification, superficial and deep sensitivity, and the status of the pulses were documented. In group 1, the control group, conventional treatment was used. Group 2, the experimental group, was also treated conventionally but a negative pressure device was added. The wounds were treated until healed or for one year. A statistical analysis was carried out with parametric tests that compared the evolution of the ulcer and the amputation level in both groups. Results: The ulcer closed by one year of follow-up in ten patients from each group, representing 90.9% of the patients. A statistically significant difference was not observed between the groups. Conclusions: After one year of evolution, a statistically significant difference in ulcer healing was not found in either group

Using Simulated Annealing with a Neighborhood Heuristic for Roll Cutting Optimization

Abstract This article presents the use of the Simulated Annealing algorithm with a heuristic to solve the waste minimization problem in roll cutting programming, in this case, paper. Client orders, which vary in weight, width, and external and internal diameter, are fully satisfied. Several tests were performed with real data from a paper company in which an average of 30% waste reduction and 100% reduction in production to inventory are obtained compare to the previous procedure

A Hybrid Metaheuristic-Based Approach for the Aerodynamic Optimization of Small Hybrid Wind Turbine Rotors

This work presents a novel framework for the aerodynamic design and optimization of blades for small horizontal axis wind turbines (WT). The framework is based on a state-of-the-art blade element momentum model, which is complemented with the XFOIL 6.96 software in order to provide an estimate of the sectional blade aerodynamics. The framework considers an innovative nested-hybrid solution procedure based on two metaheuristics, the virtual gene genetic algorithm and the simulated annealing algorithm, to provide a near-optimal solution to the problem. The objective of the study is to maximize the aerodynamic efficiency of small WT (SWT) rotors for a wide range of operational conditions. The design variables are (1) the airfoil shape at the different blade span positions and the radial variation of the geometrical variables of (2) chord length, (3) twist angle, and (4) thickness along the blade span. A wind tunnel validation study of optimized rotors based on the NACA 4-digit airfoil series is presented. Based on the experimental data, improvements in terms of the aerodynamic efficiency, the cut-in wind speed, and the amount of material used during the manufacturing process were achieved. Recommendations for the aerodynamic design of SWT rotors are provided based on field experience. © 2014 José F. Herbert-Acero et al

Reinforcement Learning in the Fuzzy Classifier System

This report describes the fuzzy classifier system and a new payoff distribution scheme that performs true reinforcement learning. The fuzzy classifier system is a crossover between learning classifier systems and fuzzy logic controllers. By the use of fuzzy logic, the fuzzy classifier system allows for variables to take continuous values, and thus, could be applied to the identification and control of continuous dynamic systems. The fuzzy classifier system adapt the mechanics of learning classifier system to fuzzy logic to evolve sets of coadapted fuzzy rules. The payoff distribution scheme presented here opens the way for the use of the fuzzy classifier system in control tasks. Additionally, other mechanisms that improve learning speed are presented. Keywords Learning classifier systems, fuzzy logic, fuzzy logic control, reinforcement learning. Reinforcement Learning in the Fuzzy Classifier System January, 1997 1 Introduction Automatic control is a mature field with a vast litera..

Administración de riesgos empresariales en Colombia, México y Argentina

Administración de Riesgos Empresariales en Colombia, México y Argentina da a conocer un completo diagnóstico del desarrollo de la administración de riesgos en grandes empresas privadas de los tres países participantes, en el cual se evidencia una importante evolución de esta disciplina en el marco del gobierno y la cultura del riesgo, las prácticas y herramientas, la comunicación y consulta, entre otros elementos estudiados -- Con esto se ratifica el valor de esta disciplina para contribuir a la responsabilidad social empresarial, y el impacto en los resultados financieros y la sostenibilidad de las empresasp. 22

Visiones de la educación financiera: Análisis y perspectivas

"Visiones de la educación financiera: análisis y perspectivas es una obra que enmarca la importancia de la educación financiera en la sociedad en el contexto actual. Las decisiones que en este tema realiza un individuo pueden impactar positiva o negativamente su estabilidad económica por un periodo indeterminado, es aquí cuando la educación financiera actúa como una herramienta trascendental en su bienestar personal. Además de tener la función de armadura ante las batallas que se libran en los mercados —como la crisis financiera de 2008— funge como dinamizador de las economías al potenciar los proyectos de inversión con el aumento del emprendedurismo, impactando así en las variables macroeconómicas. Esta área del conocimiento ha adquirido importancia y popularidad a nivel internacional a raíz de las crisis económicas de los últimos años, sin embargo, aún existen, entre otras, brechas sociodemográficas, culturales, económicas, que no permiten el acceso a estas enseñanzas, excluyendo parte de la población del proceso del bienestar económico. Para ejemplificar esta desigualdad, en los capítulos se plasma un panorama internacional de la educación financiera, considerando las implicaciones y retos que han tenido las estrategias nacionales de educación financiera a nivel mundial"