Ingeniería Eléctrica

En este documento se presenta una metodologia para el reconocimiento de patrones de movimiento a partir de senales electromiograficas (EMG) del sistema fisiologico brazo - antebrazo, la cual parte del diseno y construccion de un sistema de instrumentacion para la captacion de senales teniendo en cuenta la normatividad SENIAM para electromiografia de superficie y las caracteristicas de la senal EMG. Ademas, se aplican tecnicas de procesamiento y caracterizacion basadas en: aproximacion temporal, modelamiento parametrico, FFT, STFT y Wavelets en la construccion de un conjunto de caracteristicas hibrido para ser utilizado en el reconocimiento de patrones de movimiento a partir redes neuronales.

Las posiciones antero-posteriores del nucleo talamico y las estructuras de los ganglios basales tienden a variar de acuerdo a varias condiciones como la longitud intercomisural. Esta variabilidad puede ser tenida en cuenta utilizando diferentes puntos de referencia para localizarlos, el uso de diferentes puntos de referencia provee una medida para reducir la variabilidad de los blancos quirúrgicos por medio de la correcta localización anatomica de ellos. Las variaciones latero-mediales y dorso-ventrales aparecen por otros factores anatomicos no relacionados con la longitud intercomisural como la atrofia ventricular y otros factores anatómicos. A causa de esta falta de homogeneidad no hay un procedimiento estandarizado para ajustar los datos de los diferentes cerebros y corregir esta variación individual. Uno de los métodos usados actualmente para corregir satisfactoriamente la variación anatomica es la evaluación electrofisiologica por medio de los registros MER de la actividad neur...

Stereotactic neurosurgery for Parkinson ́s disease (PD) is one of the most used treatments for relief symptoms of this degenerative disorder. Current methods include ablation and deep brain stimulation (DBS) that can be applied to the various nuclei in the basal ganglia (BG), for instance to the Subthalamic nucleus (STN) or the Ventral medial nucleus (Vim). Identification of thus regions must be rigorous and within a minimum position error. Usually, skilled specialist identifies the brain area by comparing and listening to the rhythm created by the temporal and spatial aggregation of action potentials presented in microelectrode recordings (MER). We present a novel system for automatic identification of the various nuclei in the BG which addresses the limitations of the subjectivity and the non-stationary nature of MER signals. This system incorporates the time-frequency analysis using the Hilbert-Huang Transform (HHT), which is a recent tool for processing nonlinear and non-station...

A Support Vector Machine (SVM) learns the decision surface from two distinct classes of the input points. As a one class classifier, the support vector data description is able to form a decision boundary around the learned data domain with very little or no knowledge of data points outside the boundary. Data points are mapped by means of a Gaussian kernel or other kind of kernel to a high dimensional feature space, where we search for the maximal separation between classes. This boundary function, when mapped back to data space, can separate into several components, each enclosing a separate cluster.

The finite element method (FEM) is used in many research areas like mechanical engineering, heat transference, solid devices, analysis in materials when they are put under efforts. In electrical engineering they are used in electric and magnetic field in a machine or in a transmission line.

Today maintenance is not a field with the only intention of retains a particular operational state in a system. Now it has become in a fundamental tool for all company to reach corporate objectives which always have influence over the whole productive process. Due to probabilistic nature of system components behavior, this paper shows the use of Markov Chains for maintenance policies design, indicating the way for its implementation and how to decide about different policies with the results obtained

Este artículo presenta el desarrollo de un esquema de control óptimo neuronal que parte del estudio de conceptos del cálculo variacional y su interacción con las Redes Neuronales Artificiales (RNA), generando un algoritmo de entrenamiento y una ley de control. Tal esquema ...

The reduced matrix converter (RMC) implemented in offshore wind power conversion system is investigated in this paper. The RMC is built with 6 bi-directional switches, and the losses produced by these switches are compared under different conditions. Each bi-directional switch is made up by two RB-IGBTs in antiparallel, and it is studied how the special structure of the RB-IGBT will affect the total losses of the switch. The entire offshore wind power conversion system is modeled in PSIM. The first conversion stage after the wind turbine is direct ac-ac conversion by the reduced matrix converter. Thereafter a high frequency square wave voltage is fed into a transformer. Due to the high frequency, the transformer will have reduced weight, which is an important aspect of the lightweight and compact component requirements for offshore wind turbine installations. After the transformer the second conversion stage is carried out. This is done by a full-bridge converter where the output is dc voltage, for enabling series connection of wind turbines in dc. The study is aimed at the achievement of an energy efficient converter, with high power density and reliability.