• Implementation of a transient approach for the mass and energy balance in an electric arc furnace.

      Camacho, Alejandra
      On this work, an implementation of a transient approach for the mass and energy balance in an electric arc furnace is presented. Real operation conditions were included, such as the dynamic material and energy additions and continuous inlets and outlets. Also, several inherent phenomena were characterized, such as the melting rate of scrap, the chemical reaction mechanisms and the residence time of bubbles in the slag. With all these elements, the estimation of the distribution of mass and energy flows at any time of the “heat” process was performed. The main contributions of this work are to provide a prediction of mass and energy distribution at any time of the EAF process, and to be a guideline for a dynamic optimization model which can be useful to improve the efficiency of the furnace by operation protocol modifications, therefore, the net cost per ton of liquid steel can be reduced.
    • Preparación de fibras híbridas de composito carbono-carbono

      González Dueñas, Victor Alejandro
      El principal objetivo del presente trabajo es la preparación de un composito de carbono-carbono a base fibras de alcohol polivinílico (PVA) reforzadas por diferentes nanoestructuras de carbono mediante la técnica de forcespinning con el fin de mejorar su direccionalidad y obtener una morfología homogénea. Luego mediante un proceso de pirólisis se obtuvieron fibras de carbono, con el fin de obtener un material más atractivo al mejorar sus propiedades térmicas, eléctricas y mecánicas en aplicaciones de almacenamiento de energía. Los resultados más sobresalientes de este trabajo indican la innovación del equipo de forcespinning, al modificar la geometría del dispensador de polímero incrementando la capacidad de solución por prueba y eliminando el uso de agujas o sistemas de integración de jeringas mediante una perforación sobre la cara del dispensador que permite la deposición de las fibras en la superficie obteniendo direccionalidad, se analizaron distintas concentraciones en la solución de 5, 10, 15 y 20% w/v para determinar el parámetro de velocidad rotacional para obtener un mejor procesos de producción en comparación al equipo tradicional. Además, se observó que la incorporación de las diferentes nanoestructuras de carbono en concentraciones de 0.5% w/v - 1% w/v no modifican la viscosidad de la solución lo cual evita la modificación de parámetros del equipo. La espectroscopia infrarroja (FTIR) determino que no hay un cambio estructural en el polímero y la presencia de las nanoestructuras de carbono. La microscopía electrónica de barrido (SEM) confirmó la obtención de fibras con un diámetro final de <2.1 ± 0.3 μm para cualquiera de las diversas muestras, al se agrega cloruro de sodio (NaCl), hay una disminución en el diámetro de las fibras <1.8 ± 0.2 μm de tamaño, lo cual incrementa el área superficial del material Por voltametría cíclica (CV) se estudiaron las propiedades electroquímicas de los compositos obteniendo corrientes de 10-2 y 10-3 amperes al estabilizarse por tres semanas en el electrolito dichas corrientes son mayores a las de un capacitor de cerámico comercial por lo que mejoraría la capacidad de almacenamiento de energía en dispositivos electrónicos.
    • Visualization and machine learning techniques to support web traffic analysis

      Gómez-Herrera, Fernando
      Web Analytics (WA) services are one of the main tools that marketing experts use to measure the success of an online business. Thus, it is extremely important to have tools that support WA analysis. Nevertheless, we observed that there has not been much change in how services display traffic reports. Regarding the trustworthiness of the information, Web Analytics Services (WAS) are facing the problem that more than half of Internet traffic is Non-Human Traffic (NHT). Misleading online reports and marketing budget could be wasted because of that. Some research has been done, yet, most of the work involves intrusive methods and do not take advantage of information provided by current WAS. In the present work, we provide tools that can help the marketing expert to get better reports, to have useful visualizations, and to ensure the trustworthiness of the traffic. First, we propose a new Visualization Tool. It helps to show the website performance in terms of a preferred metric and enable us to identify potential online strategies upon that. Second, we use Machine Learning Binary Classification (BC) and One-Class Classification (OCC) to get more reliable information by identifying NHT and abnormal traffic. Then, marketing analysts could contrast NHT against their current reports. Third, we show how Pattern Extraction algorithms (like PBC4cip's miner) could help to conduct traffic analysis (once visitor segmentation is done), and to propose new strategies that may improve the online business. Later on, the patterns can be used in the Visualization Tool to analyze the traffic in detail. We confirmed the usefulness of the Visualization Tool by using it to analyze bot traffic we generated. NHT traffic shared a very similar linear navigation path, contrasted with the more complex human path. Furthermore, BC and OCC (BaggingTPMiner) worked successfully in the detection of well-known bots and abnormal traffic. We achieved a ROC AUC of 0.844 and 0.982 for each approach, respectively.
    • Bearing fault diagnosis in spindles using vibration and acoustic emission

      Tamayo, Oscar
      In modern automated manufacturing processes, machinery has become more flexible and automatic but also more susceptible to conditions in different parts like spindles. The main conditions affecting them are focused in the shaft and bearings. To successfully detect and identify each condition, methodologies based on new transforms and sensors are used in controlled environments, in order to recognize the conditions effects in vibration and sound. To detect machining conditions there are two important factors: (1) The feature extraction method and (2) the type of sensor used. In feature extraction methods reviewed, Cepstrum Pre Whitening (CPW) is remarkable useful for vibration. Its main feature is suppress the shaft speed waveform of the motor in rotational machine systems and help to detect bearing faults. The main sensor used is the accelerometers to acquire vibration, but recently acoustic emission (AE) acquired from transducers are studied to improve the diagnosis along with accelerometers. In this study, an experimental system was built to acquire vibration and AE signals from faulted bearings and a methodology based on CPW, tested for vibration signals, was applied for both type of signals to compare and enhance results on machining condition monitoring. A methodology proposed using CPW, envelope spectrum, trend removal, compression and RMS limit filters (the last two just for AE) was applied to 9 vibration and 9 AE signals taken from the experimental system with the purpose of diagnosing bearing faults in the inner race (IR), outer race(OR)androllingelement(RE)inlowfrequenciesforbothsignalsandhighfrequenciesinAE. For the 18 analyzed signals, in 5 the identification of fault components were easily made, in 12 signals the fault identification was possible; but there were peaks with similar amplitudes of the fault components and in 1 signal the identification of fault components was unsatisfactory because there was no peak that matches the bearing fault frequencies. The comparison between vibration and AE showed that in 6 from 9 tests, vibration have a better result diagnosing bearing faults than AE, specifically in the IR and RE, for the remaining 3 tests that correspond to OR, AE have a better result than vibration. Finally, the high frequencies in AE revealed that just RE faults had high frequency components in one of the three analyzed tests that can be related to remarkable faults in the ball.
    • Sistema de tutoreo inteligente para el aprendizaje de las leyes de los exponentes

      García Villegas, Benjamín Eduardo; Benjamín Eduardo García Villegas
      El presente trabajo describe el diseño de un sistema de tutoreo inteligente para la simplificación de expresiones algebraicas mediante las cuatro Leyes de los Exponentes que se enseñan en el nivel preparatoria en el sistema Instituto Tecnológico y de Estudios Superiores de Monterrey. Presenta los conceptos y técnicas relativas a los principales módulos que conforman un sistema de tutoreo inteligente: el módulo experto, el módulo del estudiante, módulo instruccional, e interfaz de usuario. Entre las ventajas obtenidas con el desarrollo de este sistema se encuentran las siguientes: la sencillez de implementación, la capacidad de diagnosticar el desempeño del estudiante y, la capacidad de fungir como un medio para la práctica de ejercicios de simplificación de expresiones, en donde el usuario recibe retroalimentación del sistema.
    • Sistema de detección de color para la manufactura

      Lara Núñez, Héctor de Jesús; Héctor de Jesús Lara Núñez
    • Síntesis y caracterización de materiales moleculares

      Prado de la Paz, Olga Leticia; Olga Leticia Prado de la Paz
    • Sistema de antenas distribuidas para redes inalámbricas móviles : levantamiento, diseño, aceptación, implementación, optimización y operación para edificios corporativos

      Caudillo Arias, María del Pilar; María del Pilar Caudillo Arias
      El objetivo de esta tesis es revisar las fases que se deben llevar a cabo para implementar un sistema de antenas distribuidas DAS, en base a mi experiencia propongo las siguientes: levantamiento, diseño, aceptación, implementación, optimización y operación. --Resumen hoja IV.
    • Sistema de apoyo educacional

      Picazo Vigueras, Ma. Enriqueta Rosa; Ma. Enriqueta Rosa Picazo Vigueras
    • Sistemas de localización por GPS para dispositivos móviles Apple

      García Luna, Alberto Aldebarán; Alberto Aldebarán García Luna
      Se busca elaborar una propuesta estructural de un ambiente de desarrollo de aplicaciones móviles, partiendo de un proyecto robusto y extensible que permita la integración de diversas soluciones en una aplicación funcional.