Optimal power flow via interior-exterior method

This paper presents a new approach to the resolution of the Optimal Power Flow problem. In this approach the inequality constraints are treated by the Modified Barrier and Primal-Dual Logarithmic Barrier methods. The inequality constraints are transformed into equalities by introducing positive auxiliary variables, which are perturbed by the barrier parameter. A Lagrangian function is associated with the modified problem. The first-order necessary conditions are applied to the Lagrangian, generating a nonlinear system which is solved by Newton's method. The perturbation of the auxiliary variables results in an expansion of the feasible set of the original problem, allowing the limits of the inequality constraints to be reached. Numerical tests on the Brazilian CESP and South-Southeast systems and a comparative test indicated that the new approach efficiently resolves of the Optimal Power Flow problem. © 2007 IEEE.

El comercio exterior de productos agropecuarios latinoamericanos = Special study on trade in agricultural commodities in Latin America

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O Brasil e os demais BRICs: comércio e política

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La Coordinadora de Organizaciones Empresariales de Comercio Exterior: un caso de cooperación entre el sector público y el privado de México

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Estatística de levantamentos epidemiológicos sobre cárie dentária, publicados no brasil e no exterior, de 1960 a 2001

The epidemiological surveys are important to the deployment, implementation and evaluation of projects and health actions in a community. The planning, goals, samples, team training/calibration, carrying out and publication of results are extremely important in the epidemiological surveys. Thus, the care with the sample and statistical analysis is fundamental for the results to be consistent and trustworthy in order to be able to be inferred for all the population. The aims of this study is to investigate the statistical methodology used in papers on dental caries epidemiological surveys published from 1960 to 2001. A bibliographical survey was carried out in BBO, MEDLINE and SCIELO databases. The papers found were analyzed with regards to the statistical methodology applied in the whole study, from the sampling to the tabling of data. Most studies (72.6%) only presented the number of elements that composed the sample, without explaining the planning involved in obtaining it.

The monetary and real effects of the financial opening up of national economies to the exterior: the case of Chile 1975-1978

Includes bibliography

Repercusiones monetarias y reales de la apertura al exterior: el caso chileno

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Indicadores de comercio exterior y política comercial

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Indicadores de comercio exterior y política comercial

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Manual de comercio exterior y política comercial. Nociones básicas, clasificaciones e indicadores de posición y dinamismo

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El comercio exterior y la generación de empleo de Argentina con el MERCOSUR: la especialización exportadora e importadora de Argentina con Brasil

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Comercio exterior de bienes de capital en América Latina

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América Latina: índices del comercio exterior, 1970-1984

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América Latina: comercio exterior según la Clasificación Industrial Internacional Uniforme de Todas las Actividades Económicas (CIIU)

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Origen y destino del comercio exterior de los países de la Asociación Latinoamericana de Integración

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