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Structure and mechanism analysis often involves the use of advanced simulation programs, which are not always available to users. The Davies method has proven to be an efficient and easily applied tool in this type of analysis, allowing the obtaining of the stresses present in the links and the necessary torque to keep the device in optimal operative conditions. All these standards will set the foundations for the development and proper design of the mechanism. Taking into account the afore mentioned, this article describes in detail the use and applications of the Davies method for stress and kinematic analysis of a landing gear.

Introduction: The incorporation of an autonomous learning system in robotics will allow the resolution of a large number of problems. One is the autonomous march of the humanoid robots due to its complexity in the great number of variables regarding this process.Objective: Develop algorithms that generate autonomous paths in a humanoid robot with various degrees of freedom.Methodology: The study begins with the development of stochastic algorithms with few dimensions. Then, it will be extended to n-dimensional situations. Afterward, simulation tests will be carried out. And finally, the experimental tests are performed.Results: An algorithm was generated based on the physical model of the robot to create walking paths stochastically. A simulator that contemplates the kinematic constraints, including collisions, was implemented to verify the results. In addition, one hundred experimental tests were done. With these tests, the correct operation of the trajectories was verified.Conclusions: It was verified that it is possible to create a stochastic algorithm that mixes determinant and random rules to automatically generate paths in humanoid robots, hence, extending concepts generated in two-dimensional and three-dimensional spaces to n-dimensional articulated coordinates.

Cognitive radio is a paradigm that proposes maximizing the utilization of the usable radio-electric spectrum, allowing licensed users (PUs) and non-licensed users (SUs) to simultaneously coexist through the dynamic management and assignment of spectrum resources, by integrating the stages of spectrum sensing, decision, sharing and mobility. Spectrum decision is one of the most important stages, but its optimal operation depends on the characterization sub-stage, which is in charge of efficiently estimating time gaps in which a PU won’t make use of the assigned spectrum, so that it can be used in an opportunistic fashion by SUs. The design and implementation of an algorithm based on the Long Short-Term Memory (LSTM) recurrent neural network is proposed in order to increase the success percentage in the forecasting (presence/absence) of PUs in spectrum channels. The accuracy level exhibited in the results indicates LSTM increases the prediction percentage as compared to the Multilayer Perceptron Neural Network (MLPNN) and the Adaptative Neuro-Fuzzy Inference System (ANFIS) learning models, which means it could be implemented in cognitive networks with centralized physical topologies.

Objectives: This paper aims to solve a problem of existing research for Cognitive Radio networks Unlicensed (specifically for Wi-Fi with centralized network topology), which aims at the spectral making decision stage to efficiently characterize the behavior of users (called PUs) in order to identify spectral opportunities that can be used beneficially by other wireless applications or users. Methods/ Statistical Analysis: The methodology includes capturing the dynamics of channel usage by a user in the 2.4 GHz band, later to apply a pre-processing of the data and reach an estimate for the level of modeling (based training system) and prediction. Findings: The possible solution that was raised during the development of the research was to use a Support Vector Machine (SVM) to estimate the prediction by classification. Application/Improvements: The results suggest that the use of SVM does not correspond to the methodology of artificial intelligence accurately because the level of delivered estimate is not accurate.

El objetivo del presente documento es caracterizar la dinámica de crecimiento de los rascacielos, determinar los requerimientos para efectuar la limpieza de sus ventanas e identificar las alternativas tecnológicas desarrolladas en los últimos años para la limpieza rascacielos. Asimismo, se examinan los avances y nuevas aplicaciones de los drones y se reconoce la posibilidad de implementar una plataforma voladora con brazo robótico para realizar el trabajo de limpieza de ventanas de rascacielos. Finalmente, se identifica una serie de aspectos básicos a tener en cuenta para la creación de un nuevo sistema de limpieza de ventanas de rascacielos integrando drones y brazos robóticos.

El objetivo de este trabajo es adquirir las señales EMG del brazo humano, para entrenar una red neuronal que pueda clasificar diferentes movimientos, de al menos 3 grados de libertad para controlar un brazo robótico. Para esto, se diseñó la adquisición y el acondicionamiento del sistema de señales EMG. Los músculos responsables del movimiento de la mano, el antebrazo y el brazo se identificaron para ubicar los electrodos en el músculo indicado. Se empieza con una posición de referencia para el movimiento de la mano, el antebrazo y el brazo. Las señales del sistema de adquisición y acondicionamiento se enviaron a la tarjeta de desarrollo ADC, donde se implementó un algoritmo que analizó la grabación de señales EMG para generar los datos con los que se entrenó la red neuronal. Luego, la red neuronal se implementó en el sistema integrado (BEAGLEBONE Black Rev. C) y se combinó con el brazo robótico.

Resumen: En este trabajo se plantea una estrategia de control enfocada en la produccion de crudo en un sistema de bombeo electro-sumergible, utilizando un controlador difuso implementado en un PLC. Para la etapa de identificacion del proceso se adquiere los datos de un pozo de produccion de crudo modelando el sistema y asi estableciendo las variables que determinan el proceso. Se realiza el diseno y ajuste del controlador difuso por Matlab, para implementar el controlador difuso utilizado el software Fuzzy Designer y un PLC ControlLogix L61. Palabras clave: Identificacion y modelado de sistemas, Control difuso, control PID, PLC, produccion de crudo.

In this study we present a new technological approach for the fabrication of ultrapure organically modified gold nanoparticles (AuNPs) for chemical sensing applied to exhaled breath analysis. To achieve a high purity level of the sensing films, we combined Advanced Gas Deposition (AGD) technique to deposit ultrapure monodispersed AuNPs, and dip coating process for functionalization of the AuNPs with thiolated organic ligands. Morphology and surface analysis revealed the deposition of ultrapure isolated AuNPs after the first processing step, and a network of nanoparticle–ligand nanoassemblies after the second processing step. Gas sensing measurements were performed with exhaled breath samples collected from a group of smokers, a group of non-smokers, and ambient air. Sensors responses towards these samples demonstrated characteristic responses for each study group. PCA analysis further revealed samples classification in three distinct characteristic clusters, which indicates the suitability of the molecularly modified AuNPs presented in this communication for breath analysis applications.

In this work is carried out an investigation of the behavior of the volatile that emit the fruits contaminated in relation to those that are totally organic through an electronic nose, the aim is to achieve a qualitative classification into two classes, presence of pesticide and organic food, this which allows is to reduce the rates of diseases because of the excessive contamination of the food and create a new methodology through a low-cost electronic equipment that is a tool for small and medium-sized farmers.

In this study we present a new technological approach for the fabrication of ultrapure organically modified gold nanoparticles (AuNPs) for chemical sensing applied to exhaled breath analysis. To achieve a high purity level of the sensing films, we combined Advanced Gas Deposition (AGD) technique to deposit ultrapure monodispersed AuNPs, and dip coating process for functionalization of the AuNPs with thiolated organic ligands. Morphology and surface analysis revealed the deposition of ultrapure isolated AuNPs after the first processing step, and a network of nanoparticle-ligand nanoassemblies after the second processing step. Gas sensing measurements were performed with exhaled breath samples collected from a group of smokers, a group of non-smokers, and ambient air. Sensors responses towards these samples demonstrated characteristic responses for each study group. PCA analysis further revealed samples classification in three distinct characteristic clusters, which indicates the suitability of the molecularly modified AuNPs presented in this communication for breath analysis applications.

In this paper, a new variable selection technique inspired in sequential forward selection but specifically designed to work with support vector machines is introduced. The usefulness of the variable selection coupled to support vector machines for solving classification and regression problems is assessed by analysing two different databases. The first database corresponds to different concentrations of vapours and vapour mixtures measured with a metal oxide gas-sensor e-nose and the second database corresponds to different Iberian hams measured with a mass-spectrometry based e-nose. Using a reduced set of important variables (i.e. reducing the dimensionality of input space by the variable selection procedure) results in support vector machines with better performance. For example, the success rate in ham classification (11-class problem) rises from 79.91% (when all the variables available are used) to 90.30% (when a reduced set of input variables is used). Furthermore, a quantitative analysis of ham samples with good accuracy is shown to be possible: when the variable selection process introduced is coupled to support vector machine regression models, the correlation coefficients of actual versus predicted humidity, water activity and salt in ham samples are 0.975, 0.972 and 0.943, respectively. This compares favourably with the correlation coefficients obtained when no variable selection is performed (0.937, 0.924 and 0.894).

We address the problem of variable selection within the pattern recognition engine of multisensor systems. This problem arises when there is high dimensionality in the data used for training (e.g. because a high number of sensors are used, or because many features are extracted from the response of each sensor, or both). Different variable selection techniques (including deterministic and stochastic methods) have been coupled with neural network-based classifiers. The usefulness of each technique implemented is benchmarked by evaluating its performance in terms of three objective parameters: the success rate in classification, the dimensionality of the final set of variables used for training and the time needed to complete the variable selection procedure. The database consisted of 96 measurements of ammonia, acetone and o-xylene vapours and their binary mixtures gathered using a metal oxide gas sensor array. Each measurement was described by 120 variables (12 sensors and 10 parameters each). A new strategy for variable selection, which is based on a two-step approach, is introduced that leads to the building of parsimonious classification models based on either the fuzzy ARTMAP or the probabilistic neural networks. For example, a 91.66% success rate in the simultaneous identification and quantification of the species and their mixtures was obtained using nine input variables only (out of the 120 available). This process of variable selection was conducted in two-step, i.e. a coarse selection based on a variance criterion followed by a simulated annealing process. This two-step variable selection took about 10 min to complete in a Pentium 4 PC platform.

Considerable attention has been given to strategies for variable selection in gas analysis using multisensor systems. Of the stochastic methods, genetic algorithms (GAs) have been found to be useful for variable selection, although they do not prevent irrelevant variables from being selected. Here we introduce the cascaded genetic algorithm, a new and simple approach that removes initially selected irrelevant variables. We coupled the method to the fuzzy ARTMAP classifier and used it to analyze single vapors and binary mixtures of three volatile organic compounds using a 12-element metal oxide gas sensor array. The method allowed to reduce the number of variables used to build the classifiers from 120 down to nine, which significantly increased the generalization ability of the fuzzy ARTMAP classifier. Success rates of 91.67 and 88.33% were reached in the simultaneous identification, quantification of single vapors, and in the identification of single vapors and their binary mixtures, respectively.

espanolSe describen los elementos fundamentales que componen la radio cognitiva y se analiza la asignacion de bandas espectrales. Dentro de los principales problemas en la insercion de nuevas aplicaciones y tecnologias inalambricas, esta la falta de espectro radioelectrico para su asignacion, debido a la manera ineficiente de distribucion del espectro radioelectrico disponible, que es actualmente asignado de forma estatica. La radio cognitiva nace como un metodo que propone una solucion a la problematica, gestionando dinamicamente el recurso. Una de las etapas que integran esta tecnologia es la decision de espectro, en la que se selecciona y asigna las bandas frecuenciales a partir de los requisitos de calidad de servicio de los usuarios cognitivos. Este articulo plantea una propuesta para el desarrollo de un proyecto de investigacion que optimice el proceso de seleccion de canales reduciendo el tiempo de asignacion para elevar su rendimiento. EnglishFundamental elements of the cognitive radio and assignment of spectral bands are described and analyzed. Among the main problems in the insertion of new applications and wireless technologies is the lack of radio spectrum for allocation due to the inefficient distribution of available radio spectrum, which is statically allocated at present. The cognitive radio paradigm was born as a method for proposing a solution to the problem, dynamically managing the resource. One of the stages that make up this technology is the decision of the spectrum that selects and allocates frequency bands based on quality of service requirements of the cognitive users. This article presents a proposal for the development of a research project that optimizes the selection of channel allocation by reducing the time to improve their performance

The morphologic and functional study of cardiovascular system is of vital importance because problems related to this system are one of the main causes of mortality in the world. It is important to mention that the left ventricle (VI) is the most susceptible to suffer severe damage, in diseases, such as arterial hypertension, mellitus diabetes or arteriosclerosis. This article presents a new methodology directed to segmentation of left ventricular contours, in angiographic images by using Generalized Hough Transform (TGH). It is important to obtain the ventricular edge, because analyzing processes of systole and diastole end, it is possible to calculate parameters of the cardiac functionality as the end-diastolic volume, end systolic volume, ejection fraction, cardiac output, Hyperkinéticos, Hypokinéticos segments, and normal; in this work we focus only on the removal of the same.

En el presente estudio se describe un análisis general de los distintos mecanismos y procedimientos aplicados al análisis del aliento para diagnostico precoz de diferentes enfermedades.En gran parte de estos métodos se da a conocer que la mayoría del contenido del aliento exhalado está formado por una gran variedad de compuestos (por ejemplo: nitrógeno, oxígeno, de dióxido de carbono, agua, gases inertes, entre otros). Las fuentes de estos volátiles son los componentes atmosféricos que se originan a partir de muchos disolventes y productos a base de petróleo, y otros compuestos orgánicos volátiles que se generan como resultado de los procesos bioquímicos del cuerpo.En la mayoría de los estudios encontrados describen los diferentes sistemas de muestreo y dispositivos de medición, de los cuales en este estudio se referencian los que son aplicados a enfermedades terminales (por ejemplo, el cáncer).

This article presents the implementation of an Electronic Nose (EN) based on the development of a measuring chamber composed of a matrix of 6 metal oxide gas sensors with partially overlapping sensitivities, to identify and classify the volatiles emitted from the exhaled breath of a group of healthy people and another group with samples of patients with Chronic Obstructive Pulmonary Disease (COPD). A set of algorithms for pre­processing and signal processing based on techniques of feature extraction and statistical methods as Principal Component Analysis (PCA), for pattern recognition of data set were implemented. From the exhalation breath samples of these patients, the results were important, due to the classification of the patients with the disease as well as of the healthy voluntary group. En este artículo se presenta la implementación de una Nariz Electró­nica (NE), la cual fue desarrollada a partir de una cámara de medida, compuesta por un conjunto de 6 sensores de gases de óxidos metálicos con sensibilidades parcialmente solapadas, con el objetivo de identificar y clasificar los volátiles emitidos a través del aliento exhalado obtenido de un grupo de personas sanas y pacientes con síntomas de la Enferme­dad Pulmonar Obstructiva Crónica (EPOC). Se implementaron un con­junto de algoritmos para el pre-procesamiento y procesamiento de señales, con base en técnicas de extracción característica y métodos estadísticos, como el Análisis de Componentes Principales (ACP), para el reconocimiento de patrones del conjunto de datos. De las muestras de aliento exhalado de estos pacientes se obtuvieron resultados importantes, debido a la clasificación de pacientes con la enfermedad, así como la de un grupo de voluntarios sanos.

This paper deals with the evaluation of different bio-inspired algorithms techniques that allow reduce harmonic distortion (THD) in pulse width modulation (PWM) of power inverters. It is performed a comprehensive study which identifies and develops biologically inspired optimization algorithms based mainly on tabu search, genetic algorithms, particle swarm optimization and ant colony optimization. Bio-inspired optimization methods are used to find the best operational parameters of a PWM applied to a power inverter.

Industrial processes are characterized to be in open environments, with high uncertainty, unpredictability and nonlinear behavior. They have to be monitored and measured rigorously due to their behavior having a direct and serious impact on product quality, safety, productivity, pollution and finance. However, industrial processes have enormous volumes of complex and high dimensional data available, with poorly defined domains and redundant, noisy or inaccurate measures with unknown parameters. Therefore, using just relevant and informative variables will decrease the high dimensionality and will facilitate the use of techniques to find patterns in data to correctly identify the functional states of the process, improving the performance of monitoring and measuring tasks. In this paper, we address the problem of sensor selection in industrial processes, where a mathematical or structural model and the class labels are not available or suitable. We propose a wrapper feature selection approach based on clustering, to perform an accurate process dataset classification with minimal variables needed. The proposed method is applied on an intensification reactor, the ’open plate reactor (OPR)’, over thiosulfate and esterification reactions. Results are compared with previous work on the same datasets showing that fewer variables are needed to correctly identify all the functional states of the process.

High dimensionality is inherent to MS-based electronic nose applications where hundreds of variables per measurement (m/z fragments) - a significant number of them being highly correlated or noisy - are available. Feature selection is, therefore, an unavoidable pre-processing step if robust and parsimonious pattern classification models are to be developed. In this article, a new strategy for feature selection has been introduced and its good performance demonstrated using two MS e-nose databases. The feature selection is conducted in three steps. The first two steps are aimed at removing noisy, non-informative and highly collinear features (i.e., redundant), respectively. These two steps are computationally inexpensive and allow for dramatically reducing the number of variables (near 80% of initially available features are eliminated after the second step). The third step makes use of a stochastic variable selection method (simulated annealing) to further reduce the number of variables. For example, applying the method to an Iberian ham database has resulted in the number of features being reduced from 209 down to 14. Using the surviving m/z fragments, a fuzzy ARTMAP classifier was able to sort ham samples according to producer and quality (11-category classification) with a 97.24% success rate. The whole feature selection process runs in a few minutes in a Pentium IV PC platform. © 2006 Elsevier B.V. All rights reserved., This work was funded in part by CICYT under project no. TIC2003-06301, by the Thematic Network in Metabolism and Nutrition ref. C03/08 and by AECI under project no. 39/04/P/E

A new procedure for variable selection, which runs in two steps, is introduced. First, an unsupervised and very fast variable selection procedure is applied: a parameter that accounts for the correlation between the features available is computed and, only near 20% of initial variables (those that are less collinear) are retained for further selection. Then, a fine-tuning selection based on a deterministic method (stepwise) coupled to a simple probabilistic neural network is conducted on the variable subset that resulted from the first selection step. The method is demonstrated using a database consisting of vapors of ethanol, acetone and toluene and their binary mixtures (120 variables). Vapors can be simultaneously identified and quantified with a 95.83% success rate and the time needed for the whole process is about 5 minutes in a Pentium 4 PC platform. Being unsupervised, the fast variable selection method applies generally, even in aroma analysis problems where category discovery is an issue. This is illustrated by applying the method to mixture analysis using direct mass spectrometry

En este artículo se presenta el modelamiento de un sistema de separación bifásica que hace parte de una etapa de recibo inicial en una estación de recolección de crudo, a través de técnicas de identificación basadas en inteligencia artificial. Adicional a la identificación del sistema realizada por dos técnicas diferentes, el modelo obtenido se emplea para realizar la sintonización del lazo de control formado por este y por un controlador de tipo Fuzzy basado en conocimiento experto.

Uno de los grandes desafíos de la radio cognitiva es establecer la forma adecuada para realizar predicciones futuras en las diferentes fases que componen un radio cognitivo. A partir de las estimaciones se puede determinar el estado y características de los canales, la actividad de los usuarios primarios y secundarios, la movilidad espectral; todo ello con el fin de que los nodos no licenciados puedan aprovechar adecuadamente y de manera oportunista las bandas subutilizadas. En este artículo se presenta una revisión de algunas de las técnicas más relevantes que han sido aplicadas en la predicción espectral en la Radio Cognitiva.

Este artículo propone el diseño y construcción de un sistema robotizado de clasificación de brevas para la gestión agroempresarial. El proyecto tiene dos objetivos principales, El primero contribuir con el desarrollo agroempresarial de la región y el segundo, desarrollar una plataforma de bajo costo que permita a los estudiantes de robótica fortalecer sus conocimientos en cinemática, dinámica, planeación de trayectorias, diseño mecatrónico, programación, control y tratamiento de imágenes. El proyecto incluye el desarrollo de una banda transportadora, un brazo antropomórfico de 5 grados de libertad y un sistema de visión artificial. Por último se exponen los resultados de las simulaciones, construcción del prototipo, planificaciones de trayectorias basado en la realimentación visual y las conclusiones.

We introduce a new variable selection approach, which converges much faster to the optimal set of variables for a given application. The new procedure runs in two steps. First, a coarse and very fast variable selection procedure is applied: A figure of merit is defined and computed for every variable, a threshold value set and only the variables whose figure of merit is higher than the threshold are retained for further selection. Then, a fine-tuning selection based either on deterministic or stochastic methods is conducted on the variable subset that resulted from the first step. The method is demonstrated using a database consisting of vapors of ethanol, acetone and toluene and their binary mixtures (120 variables/measurement). Vapors can be simultaneously identified and quantified with a 92.7% success rate and the time needed for variable selection is reduced at least by a factor of 4.