Scielo RSS <![CDATA[Journal of applied research and technology]]> vol. 11 num. 6 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<b>An Energy-efficient Routing Protocol for MANETs</b>: <b>a Particle Swarm Optimization Approach</b>]]> Mobile ad hoc networks (MANETs) are infrastructure-free networks created by wireless mobile devices with restricted battery life. This limited battery capacity in MANETs makes it necessary to consider the energy-awareness feature in their design. Since routing protocols have central role in MANETs, their energy-awareness increases network life time by efficiently using of the available limited energy. TORA is one of these routing protocols that offer high degree of scalability. This paper employs the Binary Particle Swarm Optimization algorithm (BPSO) to add the energy-awareness feature to the TORA routing protocol. The proposed protocol considers routes length in its route selection process and also includes routes energy level in its calculations. It formulates the routing issue as an optimization problem and then employs BPSO to choose a route that maximizes a weighted function of the route length and the route energy level. Extensive simulations in ns-2 simulator environment show that the proposed routing protocol, called BPSO-TORA, prolongs the network lifetime remarkably and outperforms TORA in terms of network life time, system life time and total delivered data. <![CDATA[<b>Path Analysis Development Based on Balanced Scorecard in Order to Identify Causal Relationships of Science and Technology Indices (Case Study in Iran University of Science & Technology)</b>]]> The main aim of this paper is to investigate the causal relationships among science and technology indices used by universities. This is investigated using workflow automation and interactive planning in order to take control of competitive environment, and consequently to enhance the adaption rate of universities to uncontrolled changes. The science and technology indices were categorized into five domains of communication and international relationships, research and technology, education and culture, postgraduate education, budgets and utilities and infrastructures. The indices of Iran University of science and technology were first evaluated according to concepts of interactive planning and intelligent agents. These indices are research-based, and the most important ones were identified in each field according to experts' opinion. The conceptual model was then designed. <![CDATA[<b>Microwave Energy for Expanding Perlite Ore</b>]]> Perlite is an igneous mineral composed by silicon, aluminum, oxygen and water. It can be expanded by heating it up at temperatures above 870 °C, then it becomes plastic, and the steam formed inside pressures out of the mineral. Maximum expansion is possible if the particles are heated up quickly, since the expansion degree strongly depends on the remaining water in the particles at the time that they reach the temperature where they become plastic. The typical expansion process consist in pouring the particles in rotary kilns operated with natural gas, but it is proposed in this research that the particles can be heated quickly with microwaves at 2.45 GHz. Particles of 0.08 cm and 0.018 cm of average diameter were expanded 10 to 20 times.<hr/>La perlita es un mineral ígneo compuesto de silicio, aluminio, oxígeno y agua. Se puede expander si se le calienta a más de 870 °C, entonces se vuelve plástica, y el vapor que se forma en el interior de las partículas de perlita presiona al mineral hacia afuera causando su expansión. La expansión máxima es posible cuando las partículas de perlita se calientan rápidamente, dado que el grado de expansión depende fuertemente de la cantidad de agua que aun esté presente en las partículas al momento que éstas alcanzan la temperatura en que se vuelven plásticas. El proceso de expansión típico consiste en vaciar las partículas en hornos rotatorios que operan con gas natural, pero en esta investigación se propone que las partículas pueden ser calentadas rápidamente con microondas de 2.45 GHz. Las partículas de perlita de 0.08 cm y de 0.018 cm de diámetro promedio se expandieron 10 a 20 veces. <![CDATA[<b>Real-Time Verification of Integrity Policies for Distributed Systems</b>]]> We introduce a mechanism for the verification of real-time integrity policies about the operation of a distributed system. Our mechanism is based on Microsoft .NET technologies. Unlike rival competitors, it is not intrusive, as it hardly modifies the source code of any component of the system to be monitored. Our mechanism consists of four modules: the specification module, which comes with a security policy specification language, geared towards the capture of integrity policies; the monitoring module, which includes a code injector, whereby the mechanism observes how specific methods of the system, referred to by some policy, are invoked; the verifier module, which examines the operation of the distributed system in order to determine whether is policy compliant or not; and, the reporter module, which notifies the system is policy compliant, or sends an alert upon the occurrence of a contingency, indicating policy violation. We argue that our mechanism can be framed within the Clark and Wilson security model, and, thus, used to realise information integrity. We illustrate the workings and the power of our mechanism on a simple, but industrial-strength, case study.<hr/>En este artículo, presentamos un mecanismo para verificar, en tiempo-real, políticas de integridad asociadas con un sistema distribuido. Nuestro mecanismo está desarrollado en, y es aplicable a, tecnologías MS .NET. A diferencia de sus competidores, no es intrusivo, pues no requiere modificaciones de consideración en el código fuente de ningún componente del sistema a inspeccionarse. Nuestro mecanismo consiste de cuatro módulos: el módulo de especificación, diseñado especialmente para expresar políticas de integridad; el módulo de inspección, el cual incluye un inyector de código, a través del cual nuestro mecanismo observa cómo se invocan los métodos del sistema referidos en alguna de las políticas; el módulo verificador, el cual examina la operación del sistema para determinar si éste cumple o no con las políticas; y, el módulo reportador, que notifica si el sistema está conforme a la norma, o envía alertas en el caso que ocurra una contingencia, indicando la violación a una política. Demostramos que nuestro mecanismo formalmente se enmarca dentro del modelo de seguridad de Clark y Wilson, y, por lo tanto, puede aplicarse en el establecimiento de integridad. Para mostrar el funcionamiento y las bondades de nuestro mecanismo, incluimos un caso de estudio simple, pero típico de una aplicación industrial o comercial. <![CDATA[<b>Delay aware Reactive Routing Protocols for QoS in MANETs</b>: <b>a Review</b>]]> Mobile Ad Hoc Networks (MANETs) are wireless networks, which do not require any infrastructure support for transferring data packets between mobile nodes. These nodes communicate in a multi-hop mode; each mobile node acting both as a host and router. The main function of Quality of Service (QoS) routing in MANETs is to establish routes among different mobile nodes that satisfy QoS requirements such as bandwidth, end-to-end delay and to be able operate within the limited energy constraints. Efficient QoS routing protocols are required by most commercial, real-time and multimedia applications. Ad Hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR) protocols are two of the most on-demand protocols used in MANETs. These protocols use shortest path as a main metric to establish routing between source and destination. However, they are designed primarily as best effort services and as such they do not fully heed QoS requirements as required by MANETs. This paper presents an overview of reactive routing protocols in QoS which use delay as a main metric. <![CDATA[<b>A Meta-planing Systemic Model for Mexican Public Universities</b>]]> Planning has been performed in Mexican public universities, since the 1940s, as a function promoted by government policies. However, the results were not as expected. We found through an exploratory study that this lack of planning efficiency derived from the obsolete planning conceptions and methods adopted. In this paper a meta-planning model is proposed, based on the application of complexity sciences to social organization problems. In this context, only an eminently participative meta-planning process would allow to impulse change and development at the Mexican public universities. <![CDATA[<b>An Ultrasonic Levitator</b>]]> We report the development of an ultrasonic levitation system. Liquid drops or solid samples of diameter less than one half wavelength of the excitation frequency are levitated without contact just below the pressure nodes. The piezo transducer is excited by an ultrasonic signal of around 29 kHz through a voltage amplifier. The choice of the number of half-waves of the acoustic field in the space between the reflector and radiator is made by means of a micrometer. A lamp, an amplifier and a frequency generator are integrated to the levitator. The diameters of the droplets of liquid that can levitate are of the order of tenths of mm to 3 or 4 mm, depending on the liquid properties (density, surface tension, etc.). Solid objects can also be levitated. The maximum voltage of the system is 20 Vrms.<hr/>Se presenta el desarrollo de un sistema de levitación acústica ultrasónica. Gotas líquidas o muestras sólidas de diámetro inferior a media longitud de onda a la frecuencia de excitación levitan sin contacto justo por debajo de los nodos de presión. El transductor piezoeléctrico es excitado por una señal ultrasónica de aproximadamente 29 kHz a través de un amplificador de voltaje. La elección del número de semilongitudes de onda del campo acústico en el espacio entre el reflector y el radiador se hace por medio de un micrómetro. Una lámpara, un amplificador y un generador de frecuencia están integrados al levitador. Los diámetros de las gotitas de líquido que se pueden levitar son del orden de décimas de mm a 3 ó 4 mm, dependiendo de las propiedades del líquido (densidad, tensión superficial, etc.). Se pueden levitar también objetos sólidos. El voltaje máximo del sistema es de 20 Vrms. <![CDATA[<b>Critical Factors toward Successful R & D Projects in Public Research Centers</b>: <b>a Primer</b>]]> Mexican Public Research Centers (PRCs) have become one of the most important actors in technology development for most enterprises they interact with. Nevertheless, knowledge generated and accumulated by PRCs is being underutilized or not utilized at all in the advance of new projects to benefit productive sectors. In this paper we review a number of variables to pinpoint factors that either promote or hinder successful R & D projects; i.e. those transferred to the industry. We conclude that it is feasible to design policies to boost positive factors while preventing or reducing the impact of the negative ones.<hr/>Los Centros Públicos de Investigación (CPI) mexicanos se han convertido en uno de los actores más importantes en el desarrollo tecnológico de numerosas empresas. Sin embargo, el conocimiento generado y acumulado por los CPI está siendo subutilizado o no utilizado del todo en el diseño de nuevos proyectos que podrían beneficiar al sector productivo. En este artículo analizamos una serie de variables con el propósito de identificar los factores que promueven u obstaculizan la transferencia de proyectos de I+D a la industria. Se concluye que es posible diseñar políticas que fomenten la acción de factores positivos al tiempo que prevengan o eviten el impacto de los negativos. <![CDATA[<b>Numerical Study of Diodicity Mechanism in Different Tesla-Type Microvalves</b>]]> Microvalve is one of the most important components in microfluidic systems and micropumps. In this paper, three-dimensional incompressible flow through a Tesla-type microvalve is simulated using FLUENT computational fluid dynamic package. The flow is laminar and SIMPLE algorithm is used. The second-order upwind method is implemented for discretizing convective terms. The diodicity mechanism is investigated in detail for three different microvalves. Effect of several series Tesla-type microvalves on diodicity is also studied. The numerical analyses reveal that the mechanism of diodicity occurs at the T-junction and side channel. If inlet and outlet channels are eliminated, diodicity can be increased by 2. Pressure field analysis shows that the pressure drop is much severe at the junction of the reverse flow compared to the forward flow. The obtained numerical results are compared with those of experimental and a good agreement between them is noticed. <![CDATA[<b>Fuzzy logic scheme for tip-sample distance control for a low cost near field optical microscope</b>]]> The control of the distance between the surface and the tip-sample of a Scanning Near Field Optical Microscope (SNOM) is essential for a reliable surface mapping. The control algorithm should be able to maintain the system in a constant distance between the tip and the surface. In this system, nanometric adjustments should be made in order to sense topographies at the same scale with an appropriate resolution. These kinds of devices varies its properties through short periods of time, and it is required a control algorithm capable of handle these changes. In this work a fuzzy logic control scheme is proposed in order to manage the changes the device might have through the time, and to counter the effects of the non-linearity as well. Two inputs are used to program the rules inside the fuzzy logic controller, the difference between the reference signal and the sample signal (error), and the speed in which it decreases or increases. A lock-in amplifier is used as data acquisition hardware to sample the high frequency signals used to produce the tuning fork oscillations. Once these variables are read the control algorithm calculate a voltage output to move the piezoelectric device, approaching or removing the tip-probe from the sample analyzed.<hr/>El control de la distancia entre la superficie y la punta de sensado de un microscopio de escaneo de campo cercano (SNOM por sus siglas en inglés) es esencial para un mapeo superficial confiable. El algoritmo de control tiene que ser capaz de mantener al sistema a una distancia constante entre la punta y la superficie de interés. Se requieren ajustes nanométricos para poder recuperar una topografía con una resolución apropiada, debido a que los cambios en la superficie son en escala nanométrica. Este tipo de dispositivos cambian sus propiedades a lo largo de un periodo de tiempo muy corto, para resolver este problema se necesita un algoritmo de control que sea capaz de manejar estos cambios. En este trabajo se propone un esquema de lógica difusa para de esta manera poder compensar los cambios que el dispositivo pueda presentar a través del tiempo, y para contrarrestar los efectos producidos por la no linealidad que presenta el sistema. Dos entradas fueron usadas para programar las reglas utilizadas en el controlador de lógica difusa, la diferencia entre la señal de referencia y la señal retroalimentada (error), y la velocidad en la cual disminuye o aumenta. Como dispositivo de adquisición de datos se utilizó un amplificador de amarre de fase para leer las señales de alta frecuencia usadas para producir las oscilaciones del diapasón de cuarzo. Una vez que se adquieren estas variables podemos manipularlas por medio del algoritmo de control para calcular una salida de voltaje la cual mueve el dispositivo piezoeléctrico, retrayendo o extendiendo la punta hacia la muestra analizada. <![CDATA[<b>Use of ANFIS Control Approach for SSSC based Damping Controllers Applied in a Two-area Power System</b>]]> In an interconnected power system, low frequency electromechanical oscillations are initiated by normal small changes in system loads, and they become much worse following a large disturbance. Flexible AC Transmission System (FACTS) devices are widely recognized as powerful controllers for damping power system oscillations. The standard FACTS controllers are linear controllers which may not guarantee acceptable performance or stability in the event of a major disturbance. To overcome the drawbacks of conventional controllers, ANFIS (Adaptive Neuro-Fuzzy Inference System) control scheme has been developed in this paper, and it has been applied for the external coordinated control of series connected FACTS controllers known as Static Synchronous Series Compensators (SSSCs) employed in a two-area power system. In neuro-fuzzy control method, the simplicity of fuzzy systems and the ability of training in neural networks have been combined. The training data set the parameters of membership functions in fuzzy controller. This ANFIS can track the given input-output data in order to conform to the desired controller. Simulation studies carried out in MATLAB/SIMULINK environment demonstrate that the proposed ANFIS based SSSC controller shows the improved damping performance as compared to conventional SSSC based damping controllers under different operating conditions. <![CDATA[<b>Communications System for Down-Hole Measurements</b>]]> Progressively deeper and hotter oil wells have driven design modification that enhances the performance in sensors and downhole electronic instruments. Oil reservoirs in Mexico are located at mean depths of 6,000 m; as a consequence, the requirements for measuring thermodynamic and geophysical parameters are challenging. This paper describes a bidirectional communication system that exchanges data from a down-hole high pressure and high temperature (HP/HT) measurement tool to the surface installation. The communication medium is a 7 km mono-conductor 1K22 logging cable used also as a power supply transmission line. The system consists of a proprietary downhole measurement tool, composed of a HT/HP sensor and a high temperature DSP-based electronic device, and a data acquisition equipment located in the surface installation. The system employs a communication algorithm that automatically changes the carrier frequency of the modulation technique employed, to avoid issues derived from noise interference, cable attenuation and thermal drift of the front end passive elements. The laboratory tests results provide a firm basis for testing and evaluating the system in the field.<hr/>La extracción de hidrocarburos se realiza en fondos de pozo cada vez más profundos y calientes, lo cual ha impulsado modificaciones en los diseños de sensores e instrumentos electrónicos que se utilizan en estas aplicaciones para mejorar su rendimiento. Las reservas de petróleo en México se encuentran a profundidades promedio del orden de 6 000 m; por lo consiguiente, los requisitos para la medición de parámetros termodinámicos y geofísicos son un reto tecnológico. Este documento describe un sistema de comunicación bidireccional que intercambia información entre una herramienta de medición de alta presión y alta temperatura (HP/HT), ubicada en el fondo del pozo, y un equipo de medición instalado en la superficie. El medio de comunicación es un cable monoconductor de 7 km tipo 1K22 usado para descender la herramienta, el cual también se usa como una línea de transmisión de la fuente de alimentación. El sistema de comunicación consta de una herramienta de medición en fondo de pozo, la cual cuenta con solicitud de patente, y está compuesta de un sensor HP/HT, un dispositivo electrónico de alta temperatura basado en DSP y un equipo de adquisición de datos situado en la instalación de superficie. El sistema emplea un algoritmo de comunicación adaptativo que cambia automáticamente la frecuencia de la portadora de la técnica de modulación seleccionada, para evitar los problemas derivados de la interferencia de ruido, la atenuación del cable y de la deriva térmica de los elementos electrónicos. Los resultados obtenidos en las pruebas de laboratorio proporcionan una base firme para la prueba y evaluación del sistema en campo. <![CDATA[<b>Optimizing the Cellular Network Planning Process for In-Building Coverage using Simulation</b>]]> The global scenario of mobile telecommunications networks suggests that the next years the number of mobile users will continue growing as well as the services demand. The biggest growth is expected mainly in Asiatic and developing countries. Particularly, the Mexican telecommunications market suggests that if the number of mobile users will continue growing in Mexico as in the last years, then the mobile networks operators should increment the network capacity and the in-building coverage in order to maximize the quality of service. Also, network operators should offer attractive plans to users in order to maximize their economic benefits. Therefore, this research study aims to develop a simulation model to analyze the services transmission in a Third Generation mobile network and maximize the network coverage and the theoretical economic benefit of network operators. The delivered services included are voice, data and video. Using this simulation model we obtained the optimal cost-effective network design in a scenario of a Mexican airport. This design consisted of six cells, each one configured with an Omni-directional antenna and capacity of seven traffic channels. Through the traffic channels were delivered the services: sound, multimedia, narrow band and wide band, with a data rate of 12 kb/s, 128kb/s, 384 kb/s, and 1920 kb/s, respectively. The maximum economic benefit was 46.6% using the optimal network design. We propose this simulation model as a tool for decision-making support of mobile network operators in Mexico.<hr/>El escenario global de las redes móviles de telecomunicaciones sugiere que en los próximos años el número de usuarios y la demanda de servicios continuarán creciendo, sobre todo en países asiáticos y en desarrollo. Particularmente, el mercado mexicano sugiere que si el número de usuarios en México continua creciendo como en los últimos años, entonces los operadores de las redes deberán incrementar la capacidad de red y la cobertura en interiores para maximizar la calidad del servicio. Además, deberán ofrecer planes atractivos de renta a los usuarios a fin de maximizar sus beneficios económicos. Por lo tanto, el objetivo de este estudio de investigación es el desarrollo de un modelo de simulación para analizar la transmisión de servicios en una red móvil de tercera generación y en consecuencia, maximizar los beneficios económicos teóricos de los operadores y la cobertura de red, para la distribución de servicios de voz, datos y video. Utilizando modelo de simulación, se obtuvo el diseño de red óptimo basado en costo-beneficio en el escenario de un aeropuerto mexicano. Este diseño consistió de seis celdas, cada una configurada con una antena omni-direccional, y con una capacidad de siete canales de tráfico, resultando un beneficio económico máximo de 46.6%. Así, este modelo de simulación se propone como una herramienta para el apoyo en la toma de decisiones de los operadores de redes móviles en México. <![CDATA[<b>Development of an anti-vibration system for the safe transfer and reliable operation of mammography equipment on board a mobile medical unit</b>]]> This paper shows the developing process of an anti-vibration system, from its conception up to the construction of a experimental prototype. Special features and constraints that must be considered are specified, including a description and theoretical foundation of the working principle, a geometrical proposal and a component selection process, in order to ensure the effective operation of the system complying required specifications. Finally, the combination of these elements are used to design and build a experimental prototype capable to simulate the behavior of an anti-vibration system for ensuring the safe transfer and reliable operation of mammography equipment on board of a mobile medical unit.<hr/>En este trabajo se presenta el proceso de desarrollo de un sistema antivibratorio, desde su concepción (necesidad de aplicación y requisitos) hasta la construcción de un prototipo experimental que debe cumplir con ciertas características y restricciones de diseño y funcionamiento. Este proceso consta de la descripción de las condiciones de traslado de un mastógrafo instalado en una unidad médica móvil y del principio de funcionamiento de un sistema antivibratorio y su fundamento teórico, así como de una propuesta de geometría del sistema antivibratorio y de un proceso de selección de componentes. Con ello, se estaría asegurando el funcionamiento eficaz del sistema, para que cumpla con el objetivo de aislar de vibraciones el mastógrafo durante su traslado. Finalmente, se cuenta con el diseño y fabricación de un prototipo experimental, capaz de simular con él el desempeño necesario para garantizar el traslado seguro y operación confiable de un mastógrafo a bordo de una unidad médica móvil. <![CDATA[<b>Programming Real-Time Motion Control Robot Prototype</b>]]> This item presents the real-time programming of a prototype robot to control its movement from one moment to another without showing response delays. Contributing to this is the communication protocol developed in our laboratories and feasibility of being implemented in the future with wireless control via radio frequency, and to present the progress to date have been obtained.<hr/>Se presenta la programación en tiempo real de un auto prototipo para controlar su movimiento de un momento a otro sin presentar retardos de respuesta. La contribución a este mismo es el protocolo de comunicación desarrollado en nuestros laboratorios y la factibilidad de ser implementado en un futuro con control inalámbrico, a través de radio frecuencia, así como presentar los avances que hasta el momento se han obtenido.