Scielo RSS <![CDATA[Journal of applied research and technology]]> http://www.scielo.org.mx/rss.php?pid=1665-642320130005&lang=pt vol. 11 num. 5 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.org.mx/img/en/fbpelogp.gif http://www.scielo.org.mx <![CDATA[<b>General Form of Linear Programming Problems with Fuzzy Parameters</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500001&lng=pt&nrm=iso&tlng=pt In this paper, it is pointed out that the existing general form of such fully fuzzy linear programming problems in which all the parameters are represented by such flat fuzzy numbers for which is valid only if there is not a negative sign. However, if there is a negative sign, then the existing general form of fully fuzzy linear programming problems is not valid. Thus, a new general form is proposed. <![CDATA[<b>A Piecewise Linear Fitting Technique for Multivalued Two-dimensional Paths</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500002&lng=pt&nrm=iso&tlng=pt This paper presents a curve-fitting technique for multivalued two-dimensional piecewise-linear paths. The proposed method is based on a decomposed formulation of the canonical piecewise linear model description of Chua and Kang. The path is treated as a parametric system of two position equations (x(k), y(k)), where k is an artificial parameter to map each variable (x and y) into an independent k-domain.<hr/>Este artículo presenta una técnica de ajuste de curva para trayectorias lineales a tramos bidimensionales multivaluadas. El método propuesto se basa en una formulación descompuesta del modelo canónico para descripción lineal a tramos de Chua y Kang. La trayectoria es tratada como un sistema paramétrico de dos ecuaciones de posición (x(k), y(k)), donde k es un parámetro artificial para mapear cada variable (x and y) en un dominio k independiente. <![CDATA[<b>Single Maneuvering Target Tracking in Clutter Based on Multiple Model Algorithm with Gaussian Mixture Reduction</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500003&lng=pt&nrm=iso&tlng=pt The measurement origin uncertainty and target (dynamic or/and measurement) model uncertainty are two fundamental problems in maneuvering target tracking in clutter. The multiple hypothesis tracker (MHT) and multiple model (MM) algorithm are two well-known methods dealing with these two problems, respectively. In this work, we address the problem of single maneuvering target tracking in clutter by combing MHT and MM based on the Gaussian mixture reduction (GMR). Different ways of combinations of MHT and MM for this purpose were available in previous studies, but in heuristic manners. The GMR is adopted because it provides a theoretically appealing way to reduce the exponentially increasing numbers of measurement association possibilities and target model trajectories. The superior performance of our method, comparing with the existing IMM+PDA and IMM+MHT algorithms, is demonstrated by the results of Monte Carlo simulation. <![CDATA[<b>Cell Assignment in Hybrid CMOS/Nanodevices Architecture Using a PSO/SA Hybrid Algorithm</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500004&lng=pt&nrm=iso&tlng=pt In recent years, substantial advancements have been made in VLSI technology. With the introduction of CMOL (Cmos\nanowire\MOLecular Hybrid), higher circuit densities are possible. In CMOL there is an additional layer of nanofabric on top of CMOS stack. Nanodevices that lie between overlapping nanowires are programmable and can implement any combinational logic using a netlist of NOR gates. The limitation on the length of nanowires put a constraint on the connectivity domain of a circuit. The gates connected to each other must be within a connectivity radius; otherwise an extra buffer is inserted to connect them. Particle swarm optimization (PSO) has been used in a variety of problems that are NP-hard. PSO compared to the other iterative heuristic techniques is simpler to implement. Besides, it delivers comparable results. In this paper, a hybrid of PSO and simulated annealing (SA) for solving the cell assignment in CMOL, an NP-hard problem, is proposed. The proposed method takes advantage of the exploration and exploitation factors of PSO and the intrinsic hill climbing feature of SA to reduce the number of buffers to be inserted. Experiments conducted on ISCAS'89 benchmark circuits and a comparison with other heuristic techniques, are presented. Results showed that the proposed hybrid algorithm achieved better solution in terms of buffer count in reasonable time. <![CDATA[<b>A PSO Procedure for a Coordinated Tuning of Power System Stabilizers for Multiple Operating Conditions</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500005&lng=pt&nrm=iso&tlng=pt The problem of coordinated tuning stabilizers in multi-machine power systems is formulated here as a sequence of optimization problems. The design problem of stabilizers is converted to a nonlinear optimization problem with a multi-objective fitness function. The proposed method employs particle swarm optimization (PSO), an algorithm to search for optimal parameter settings of a widely used conventional fixed-structure lead-lag power system stabilizers (CPSSs). One of the main advantages of the proposed approach is its robustness to the initial parameter settings. In addition, the quality of the optimal solution does not rely on the initial guess. The robustness and performance of the newly designed controllers is evaluated in a large sixteen-machine power system subjected to different loading conditions in comparison with the genetic algorithm (GA) based PSSs design. The superiority of the controller designed is demonstrated through the nonlinear time-domain simulation and some performance indices studies. The results analysis reveals that the tuned PSSs with proposed objective function has an excellent capability in damping power system low-frequency oscillations. <![CDATA[<b>Temperature and Thermal Stresses of Vehicles Gray Cast Brake</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500006&lng=pt&nrm=iso&tlng=pt The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disc is actually used to identify the factor of geometric design of the disc to install the ventilation system in vehicles. The thermo-structural analysis is then used with coupling to determine the deformation established and the Von Mises stresses in the disc, the contact pressure distribution in pads. The results are satisfactory when compared to those found in previous studies. <![CDATA[<b>Towards the Design of Safety-Critical Software</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500007&lng=pt&nrm=iso&tlng=pt Safety is the most important factor when developing software for safety-critical systems. Traditional approaches attempted to achieve safety through testing the software. However, there might be some bugs in the software not revealed in the test procedure. Formal verification is a new trend in developing safe software. In this paper, we propose a multi-phase formal approach for safety management in safety-critical software. We use timed transition Petri-net as a formal means to specify the properties of the model and their relations in each component of the software. In addition, we use the Z language to specify textual and mathematical specifications of the model, as a representative model to evaluate the proposed approach; we chose continuous infusion insulin pump (CIIP). <![CDATA[<b>Fiber Optic Pressure Sensor of 0-0.36 psi by Multimode Interference Technique</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500008&lng=pt&nrm=iso&tlng=pt This paper presents the design, development and tests made to a fiber optic pressure sensor using the multimodal interference methodology (MMI) thus, we propose an alternative sensor to the ones available which are limited by high robust environments where the use of them is a potential hazard (explosive gases, corrosion and even electromagnetic fields). The range of work for this sensor is 0 to 0.36 psi, the arrangement used is formed by a laser diode, a sensing element, an electronic amplifying circuit, a data acquisition board and a computer. The sensing element used is a SMS fiber optic structure (singlemode-multimode-singlemode, where a multimode fiber is embedded between two singlemode fibers) placed within the contact surface (diaphragm) made of a polymeric material; the body of the sensor was made of nylamid. The bending produced in the diaphragm by the pressure inside the body of the sensor generates changes in the transmitted power response carried inside the fiber.<hr/>Se presenta el diseño, fabricación y pruebas realizadas a un sensor de presión de fibra óptica utilizando la metodología de interferencia multimodal (MMI), proponiendo así un sensor alternativo a los sensores existentes los cuales son limitados por ambientes de alto riesgo donde su uso es un peligro latente (gases explosivos, corrosión e inclusive campos electromagnéticos). El rango de trabajo para este sensor es de 0 a 0.36 psi, el arreglo utilizado está conformado de un diodo láser, elemento de sensado, circuito electrónico amplificador, tarjeta de adquisición de datos y una computadora. Como elemento de sensado se utilizó una fibra óptica SMS (por sus siglas en inglés singlemode-multimode-singlemode, formada por una fibra multimodo unida entre dos secciones de fibra monomodo) colocada dentro de una superficie de contacto (diafragma) hecha de material polimérico, el cuerpo del sensor está construido de nylamid. La deflexión producida en el diafragma por la presión dentro del cuerpo del sensor generará cambios en la respuesta de potencia transmitida a través de la fibra. <![CDATA[<b>Fuzzy Logic-Based Scenario Recognition from Video Sequences</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500009&lng=pt&nrm=iso&tlng=pt In recent years, video surveillance and monitoring have gained importance because of security and safety concerns. Banks, borders, airports, stores, and parking areas are the important application areas. There are two main parts in scenario recognition: Low level processing, including moving object detection and object tracking, and feature extraction. We have developed new features through this work which are RUD (relative upper density), RMD (relative middle density) and RLD (relative lower density), and we have used other features such as aspect ratio, width, height, and color of the object. High level processing, including event start-end point detection, activity detection for each frame and scenario recognition for sequence of images. This part is the focus of our research, and different pattern recognition and classification methods are implemented and experimental results are analyzed. We looked into several methods of classification which are decision tree, frequency domain classification, neural network-based classification, Bayes classifier, and pattern recognition methods, which are control charts, and hidden Markov models. The control chart approach, which is a decision methodology, gives more promising results than other methodologies. Overlapping between events is one of the problems, hence we applied fuzzy logic technique to solve this problem. After using this method the total accuracy increased from 95.6 to 97.2. <![CDATA[<b>Web Tools 2.0 for Health Promotion in Mexico</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500010&lng=pt&nrm=iso&tlng=pt Web Tools 2.0 are potential allies for health promotion, since they can provide the population with information in order to improve their health; they are an effective way to share knowledge within the health sector institutions. In Mexico, these tools are used by public and private organizations. We explain what Web Tools 2.0 are and which the ones mostly used in the health field are. For this, a documentary research project was carried out and scientific virtual libraries were consulted; the information was collected and analyzed, with the following results: the ones that are mostly used are the social networks, followed by the content management platforms and, finally, by the knowledge management systems. Mexico faces the challenge of increasing access to these tools for most of the population as well as extending digital literacy.<hr/>Las herramientas Web 2.0 tienen un gran potencial en el campo de la promoción de la salud, porque pueden hacer llegar información a la población con el fin de capacitarla para mejorar su salud, y constituyen un medio eficaz para difundir y compartir conocimientos al interior de las instituciones del sector salud. En México, en la promoción de la salud apoyada con estas herramientas concurren instituciones públicas, privadas y organizaciones no gubernamentales. En el presente trabajo se da a conocer qué son las herramientas Web 2.0 y cuáles son las más usadas en la promoción de la salud. Para ello se realizó una investigación documental y se consultaron bibliotecas virtuales científicas; se recuperó y analizó la información, con los siguientes resultados: las más utilizadas son las redes sociales, seguidas de los administradores de contenidos y, por último, los gestores de conocimiento. México enfrenta el reto de aumentar el acceso a éstas para la mayoría de la población y extender la alfabetización digital. <![CDATA[<b>A Survey of Intelligent Car Parking System</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500011&lng=pt&nrm=iso&tlng=pt The industrialization of the world, increase in population, slow paced city development and mismanagement of the available parking space has resulted in parking related problems. There is a dire need for a secure, intelligent, efficient and reliable system which can be used for searching the unoccupied parking facility, guidance towards the parking facility, negotiation of the parking fee, along with the proper management of the parking facility. Intelligent Parking Service is a part of Intelligent Transportation Systems (ITS). This paper reviews different Intelligent Parking Services used for parking guidance, parking facility management and gives an insight into the economic analysis of such projects. The discussed systems will be able to reduce the problems which are arising due to unavailability of a reliable, efficient and modern parking system, while the economic analysis technique will help in analyzing the projects' feasibility.<hr/>La industrialización del mundo, el aumento de población, el desarrollo de la ciudad de ritmo lento y la mala gestión del espacio de aparcamiento disponible ha dado lugar a problemas relacionados con el aparcamiento. Hay una gran necesidad de un sistema seguro, inteligente, eficiente y confiable que se puede utilizar para buscar el aparcamiento desocupada, la orientación hacia el aparcamiento, la negociación de la tarifa de aparcamiento, así como la correcta gestión de las instalaciones de aparcamiento. Servicio de Estacionamiento Inteligente es una parte de los Sistemas Inteligentes de Transporte (ITS). Este artículo revisa los diferentes Servicios de estacionamiento inteligentes utilizados para la guía, Aparcamiento gestión de instalaciones y da una idea del análisis económico de este tipo de proyectos. Los sistemas descritos podrán reducir los problemas que están surgiendo debido a la falta de un sistema de aparcamiento fiable, eficiente y moderna, mientras que la técnica de análisis económico nos ayudará en el análisis de viabilidad de los proyectos. <![CDATA[<b>Powerful Descriptor for Image Retrieval Based on Angle Edge and Histograms</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500012&lng=pt&nrm=iso&tlng=pt By gaining the place of active and important research area, Content based image retrieval has been proposed in a number of different ways after its inception. In the proposed method, a new angle orientation histogram has been introduced named as Angle Edge Histogram. By applying Pythagorean theory to image, very useful characteristics have been obtained for image matching, search and retrieval. Proposed method has also been compared with existing methods and the results show that it outperforms the existing methods in values of precision and recall and balance of precision and recall. Proposed method receives an average of 94% of precision and 79% of recall rates. <![CDATA[<b>A Survey on Femtocells</b>: <b>Benefits Deployment Models and Proposed Solutions</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500013&lng=pt&nrm=iso&tlng=pt Femtocell networks are considered to be a viable option that can fulfill the demands of high speed voice and data traffic for the indoor users. It uses the services of the existing broadband connection to connect to the operator core network. The cellular network operators need to modify the existing single tier macrocell network in order to provide the services of femtocells to its users. In this paper, we present a survey on femtocell deployment. Various aspects of femtocell networks in a diverse domain are discussed. A detailed analysis of the previous approaches is given to highlight their pros and the cons. <![CDATA[<b>Security Improvement of Two Dynamic ID-based Authentication Schemes by Sood-Sarje-Singh</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500014&lng=pt&nrm=iso&tlng=pt In 2010, Sood-Sarje-Singh proposed two dynamic ID-based remote user authentication schemes. The first scheme is a security improvement of Liao et al.'s scheme and the second scheme is a security improvement of Wang et al.'s scheme. In both cases, the authors claimed that their schemes can resist many attacks. However, we find that both schemes have security flaws. In addition, their schemes require a verification table and time-synchronization, making the schemes unfeasible and unsecured for electronic services. In order to remedy the security flaws of Sood et al.'s schemes, we propose a robust scheme which resists the well-known attacks and achieves all the desirable security goals.<hr/>En el año 2010, Sood-Sarje-Singh propusieron dos esquemas de autenticación de usuario remoto. El primer esquema presenta una mejora de seguridad sobre el esquema propuesto por Liao-Lee-Hwang en el año 2005, y el segundo esquema presenta una mejora de seguridad sobre el esquema propuesto por Wang-Liu-Xiao-Dan en el año 2009. En ambos casos, los autores claman que sus esquemas pueden resistir varios ataques. Sin embargo, nosotros hemos encontrado que ambos esquemas tienen deficiencias de seguridad. Además, los esquemas propuestos requieren de una tabla de verificación y sincronización de tiempo, haciendo a los esquemas imprácticos e inseguros para servicios electrónicos. Para remediar las deficiencias de seguridad presentadas en los esquemas propuestos por Sood-Sarje-Singh, nosotros proponemos un esquema robusto de seguridad que resiste los ataques más populares y consigue todas las metas de seguridad deseadas. <![CDATA[<b>Cropping Resilient Watermarking Based on Histogram Modification</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500015&lng=pt&nrm=iso&tlng=pt This paper proposes a watermarking scheme robust against most common geometric and signal processing operations, for applications that require an accurate detection of the owner watermark even if the digital image suffers intentional and non-intentional attacks. The proposed scheme is based on two modifications introduced in two 2D histograms. In the first modification a selected region of a 2D histogram, composed by red and green (R-G) color components, is modified according to the watermark bit sequence; while in the second modification another 2D histogram, composed by blue (B) and filtered red (R) components, is partitioned into several blocks to embed the watermark data bits. The experimental results show fairly good robustness against several geometric distortions, common signal processing operations and some quite aggressive combined attacks. A watermark robustness comparison with the related works and an analysis of the embedding method from the watermark robustness point of view are provided, in order to explain the robustness improvement of the proposed algorithm, especially against rotation and cropping attacks. The ROC curves also provided to show the desirable detection performance of the proposed method. Comparisons with the previously reported methods, based on different techniques, are also provided.<hr/>En este artículo se propone un esquema de marca de agua robusto contra operaciones de tipo geométrico así como de procesamiento avanzado de señales, orientado a aplicaciones que requieren una detección precisa de la marca de agua aun cuando la imagen sufre de ataques intencionales o no intencionales. El esquema propuesto se basa en un par de modificaciones introducidas en dos histogramas bidimensionales. En la primera de ellas, una región seleccionada de un histograma bidimensional, conformado por las componentes de color rojo y verde (R-G), se modifica de acuerdo a la secuencia de marca de agua; mientras que en la segunda modificación, otro histograma bidimensional compuesto por la componente azul (B) y una versión filtrada de la componente de color rojo (R) es particionado en varios bloques para insertar los bits de la marca de agua. Los resultados experimentales muestran una buena robustez ante diversas distorsiones geométricas, operaciones de procesamiento avanzado de señales y algunos ataques combinados algo agresivos. La robustez de la marca de agua obtenida del algoritmo propuesto y de otros trabajos relacionados, así como un análisis del método de inserción desde el punto de vista de robustez, correspondiente al método propuesto en este trabajo, son proporcionados para explicar la mejoría en la robustez del algoritmo propuesto contra ataques de rotación y recorte. Las curvas ROC también se proporcionan para mostrar las características de operación deseables del método propuesto, así como los resultados de comparación del método propuesto con otros esquemas propuestos previamente en la literatura, los cuales emplean técnicas de inserción y detección diferentes a la propuesta en este trabajo. <![CDATA[<b>Using the Monte Carlo Simulation Methods in Gauge Repeatability and Reproducibility of Measurement System Analysis</b>]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-64232013000500016&lng=pt&nrm=iso&tlng=pt Measurements are required to maintain the consistent quality of all finished and semi-finished products in a production line. Many firms in the automobile and general precision industries apply the TS 16949:2009 Technical Specifications and Measurement System Analysis (MSA) manual to establish measurement systems. This work is undertaken to evaluate gauge repeatability and reproducibility (GR & R) to verify the measuring ability and quality of the measurement frame, as well as to continuously improve and maintain the verification process. Nevertheless, the implementation of GR & R requires considerable time and manpower, and is likely to affect production adversely. In addition, the evaluation value for GR & R is always different owing to the sum of man-made and machine-made variations. Using a Monte Carlo simulation and the prediction of the repeatability and reproducibility of the measurement system analysis, this study aims to determine the distribution of % GR & R and the related number of distinct categories (ndc). This study uses two case studies of an automobile parts manufacturer and the combination of a Monte Carlo simulation, statistical bases, and the prediction of the repeatability and reproducibility of the measurement system analysis to determine the probability density function, the distribution of % GR & R, and the related number of distinct categories (ndc). The method used in this study could evaluate effectively the possible range of the GR & R of the measurement capability, in order to establish a prediction model for the evaluation of the measurement capacity of a measurement system.