Several high voltage condenser type OIP (oil impregnated paper) bushings used in the electrical industry are filled with dodecylbenzene, because of its ability to absorb hydrogen formed by corona partial discharges thick paper insulation these pieces equipment. Some them form large quantities ethane, raising concern overheating faults their insulation, which may be risky for safe operation serv...

Esta investigación analizó las representaciones semióticas de estudiantes en la conceptualización los números racionales. Se realizó con grado séptimo un colegio privado Tunja, Boyacá, cuales presentaron dificultad aprehensión conceptual del objeto matemático, dado que ocasiones no emplearon por lo menos una tres acciones cognitivas relacionadas semiosis identificación, tratamiento y conversión...

Power transformers play an important role in electrical systems; being considered the core of electric power transmissions and distribution networks, owners users these assets are increasingly concerned with adopting reliable, automated, non-invasive techniques to monitor diagnose their operating conditions. Thus, monitoring conditions has evolved, sense that a complete characterization oil–pap...

We first give a fast algorithm to compute the maximal Lyndon word (with respect to lexicographic order) ofLy (A) for every given multidegree in N . We then give an algorithm to compute all the words living in Ly (A) for any given in N . The best known method for generating Lyndon words is that of Duval [1], which gives a way to go from every Lyndon word of length n to its successor (with respec...

It is shown that a (curved) projective structure on a smooth manifold determines on the Poisson algebra of smooth, fiberwise-polynomial functions on the cotangent bundle a one-parameter family of graded star products. For a particular value of the parameter (corresponding to half-densities) the star product is symmetric, and specializes in the projectively flat case to the one constructed previ...

The fault diagnosis of the dissolved gas analysis (DGA) of the power transformer is to be enhanced than previous adopted techniques; this paper proposes a novel adaptive neuro Fuzzy inference system for the incipient fault recognition through enhanced approach. Complying with the practical DGA records and associated fault causes as much as possible, an ANFIS algorithm is presented to establish ...

This paper investigates usability problems of indexation tools for Learning Objects. Such tools are used to describe and deploy learning objects with their metadata in Learning Object Repositories (LOR’s). Metadata is provided to facilitate the search and management of learning objects. The complexity of manually indexing learning objects results in a bottleneck for the introduction of such obj...