Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Green chemically developed metal oxide polymeric composites for improving strawberry storage(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-11-15) Sani, Ayesha; Sánchez Rodríguez, Elvia Patricia; emimmayorquin; Ehsan, Muhammad; Qadir, Ghulam; Pérez Loredo, María Guadalupe; School of Engineering and Sciences; Sede EGADE Estado de México; Melo Maximo, Dulce ViridianaGlobally, the rising environmental concerns and issues related plastic wastage and spoilage of food enlightens the development of ecofriendly and sustainable alternatives for food storage to replace traditional plastic packaging material with biodegradable packaging. Polymeric coatings such as CH become a possible alternate of plastic due to its biocompatible, biodegradable and antimicrobial properties. This thesis investigates the synthesis of CH coatings for strawberry preservation. However, pure CH can limit the storage due to barrier and mechanical properties. This hindering effect in coating can be overcome by incorporating metal oxide NPs such as ZnO and Fe3O4. CH coatings were enhanced with green synthesized NPs including ZnO and Fe3O4 with the aim of prolonging food shelf life by maintaining the quality of food. The research integrates green chemistry to synthesize NPs using garlic and ginger extracts to maintain the purpose of ecofriendly coatings. The ginger and garlic extract not only serves sustainability but also act as stabilizing, reducing and capping agents for NPs synthesis. Usually, citric acid or acetic acid is used for the dissolution of CH but it is non-friendly to the environment. The preparation of citric acid and acetic acid produces toxic byproducts which is an environmental concern. Therefore, this study uses lemon juice, ginger and garlic extracts to provide acidic medium to CH for dissolution. The main objective of this research is to introduce an ecofriendly and sustainable approach in the form of polymeric nanocomposites coating solutions to preserve food. CH-ZnO and CH-Fe3O4 coatings were developed and assessed their effectiveness in preserving strawberries. Various quality parameters such as weight loss, mold growth, antioxidant activity, etc., were checked for the under-observation samples. The addition of ZnO and Fe3O4 NPs was found to enhance the barrier properties, mechanical stability as well as additional antimicrobial properties. The results concluded that CH-ZnO coatings achieved an improvement of 40% in weight loss as compared to uncoated sample. Additionally, CHFe3O4 coatings reduced the infection rate by 60% as compared to uncoated sample. The findings clearly supported the hypothesis that CH-ZnO and CH-Fe3O4 coatings present a viable, sustainable, and ecofriendly solution for extending the shelf life of strawberries. Rheological study was conducted for the coating solutions with and without NPs, showing that NPs enhancement influences the viscosity and flow behavior of coating solutions. These developed coating solutions address both food waste and environmental concerns offering a potential contribution to reduce plastic dependency in the food industry. Future work can be done to industrialize these coatings by doing further studies such as toxicity. The scalability of this approach can also be investigated in future.
- Measuring consumer attitudes about self-service technologies dimensions: an exploratory investigation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2006-01-01) Portillo Pizaña, Jesús Enrique; Portillo Pizaña, Jesús Enrique; 203764; Bloom, Paul N.; Programa Doctoral; Campus Ciudad de MéxicoThe world is getting smaller. Today, people from a small town in Mexico can find, evaluate, buy, receive, try, return or re-buy a product directly from a company located anywhere on earth. All this from the convenience of their homes - and in less than a week! Truly, they are entering the age of global digital relationships - based on information transactions between customer and companies -, where higher product quality, a wider array of information, novelty, lower costs, greater selection, and global relationships are some of the advantages offered via the Internet. Although disadvantages exist, the alternatives seem almost infinite. In the midst of many trends taking place at this historic moment – such as deregulation of industries, privatization of state-owned enterprises, geographical diversification of powerful companies and massive destruction of small ones -, there are two forces that are shaping today’s economic landscape: information technology and globalization.1 By “shaping”, we mean that we are learning to harness them, to learn from them and to channel them. They are taking form, and we are trying to contribute in a small way forming them.
- Transferencia de la capacitación al lugar de trabajo: un modelo explicativo(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2006-01-01) Salaiza Lizárraga, Flor de la Cruz; SALAIZA LIZARRAGA, FLOR DE LA CRUZ; 217592; Arriola Miranda, María Angelina; Fonseca Paredes, Maria Francisca; Silva y Ortiz, María Teresa Alicia; Campus Ciudad de MéxicoEste estudio examina los factores individuales que influyen en la transferencia de la capacitación al lugar de trabajo. Se llevó a cabo una investigación longitudinal con cuatro intervenciones: piloto, pre-test, post-test y seguimiento. En la fase piloto se encuestaron 306 participantes inscritos en cursos de capacitación impartidos por un sistema universitario multicampus en México, en las fases pre-test y post-test 154 sujetos inscritos en diplomados a distancia (vía Internet). En la fase de seguimiento se aplicó un instrumento a 21 sujetos para medir la transferencia de los conocimientos a la práctica laboral junto con una entrevista a profundidad. Los resultados mostraron que la autorregulación, como factor de personalidad; las expectativas de la capacitación como factor de motivación; las relaciones con el jefe como factor motivacional asociado al contexto laboral; y la edad junto con la antigüedad en el puesto como características sociodemográficas, fueron las variables que probaron tener un efecto en la aplicación de los conocimientos adquiridos a través de la capacitación. El modelo propuesto brinda una perspectiva integrada en cuanto a las características individuales que afectan la transferencia de la capacitación al lugar de trabajo. Los resultados tienen implicaciones en las organizaciones en lo referente gestión de recursos humanos y la organización del trabajo; en la innovación de la producción y de la tecnología; en los sistemas de medición y retroalimentación de la capacitación y en la creación de una cultura que promueva un ambiente de aprendizaje continuo e individualizado.
- Generic and modular model to develop virtual laboratories for telerobotics over the internet(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2005-11-01) Von Borstel Luna, Fernando Daniel; Von Borstel Luna, Fernando Daniel; 38419; Gordillo Moscoso, José Luis; Sucar Succar, Luis Enrique; Rodríguez González, Ciro A.; Barrón Cano, Olivia M.; Macías García, Manuel E.; Graduate Program in Information Technology and Electronics; Campus MonterreySustained advances in information and communication technologies have made it possible to access remote and globally distributed resources for instruction, information and group collaboration over the Internet. In this context, the Virtual Laboratory (VL) concept emerges to offer heterogeneous and distributed environments to perform remote experimentation by operating simulated equipment or remotely operating real equipment. Despite its importance in educational and research fields, VLs are not developed in a systematic way, since its implementation integrates multiple technologies to communicate through the Internet, control heterogeneous equipment, and simulate experiments, among others; VLs are designed and implemented based on the experience of the developer, using intuitive and tested approaches, disregarding what functionalities are needed to perform experimentation, creating partial models that ignore structural composition or behavioral design, using ad hoc architectures or development frameworks that depend on new features of interconnection technologies. Research performed in this work attempts to bridge the gap between intuitive methodologies and a formal and general methodology to develop VLs for telerobotics over the Internet. The performed research creates a generic and modular VL model with three essential elements: Guest, Media, and Host. The proposed model allows the developer to be aware of tested teleoperation strategies. The model is composed of generic entities, which are vendor and technology independent to define the appropriate configuration of desired computer-based processes in a VL for telerobotics. This model is related to the event-based control theory through a teleoperation architecture to introduce control design requirements for stable and synchronized Internet-based VL applications. The model is transformed into a reference framework, which can be customized, based on the experiment specifications. Three functionalities are defined in the reference framework to allow the user to remotely perform a true experiment: mount, define, and execute. The unified modeling language (UML) is used to describe in detail the structure and dynamics of these functionalities based on the object-oriented paradigm. The object-oriented reference framework is taken as the starting point by a general methodology to avoid costly development of new VL applications from scratch. This development methodology has four phases. The first phase analyzes the experiment and defines its functionalities and their inherent components. The second phase identifies and instantiates components into the UML framework. The customized framework describes experiment functionalities as VL subsystems. In the third phase, a novel procedure formally translates the dynamics of the customized framework into the Petri Net notation to carry out a quantitative and qualitative analysis, which relates the Petri Net design with event-based control properties. The fourth phase merges VL subsystems to compose a complete Petri Net design, which is analyzed to validate the sequential execution of VL subsystems. If necessary, the developer can synthesize Petri Net structures to control its behavior. This phase verifies that experiment functionalities perform sequentially, assuring a true experimentation, and validates that the dynamic design represents a stable event-based system over the Internet. The generated structural and dynamic designs provided by UML and Petri Net models supply a guideline to the developer to implement a VL, based on the object-oriented paradigm and the event-based control. Generated UML diagrams allow producing, high quality and low cost software artifacts. Petri Net diagrams provide a comprehensive design of the inherent control of software components. This development methodology proposes an original approach for modeling, designing, analyzing, and validating the structure and dynamics of VL applications for telerobotics. To conclude, two VLs for telerobotics are developed in this study, using the proposed methodology. A VL for mobile robotics is designed and implemented. It uses potential field and computer vision techniques to remotely plan and follow robot trajectories. After that, a VL for bilateral teleoperation that provides visual and haptic feedback is also designed and implemented. It uses a real-time event-based controller to provide sensory information. This VL application reuses software artifacts of the previously designed VL. Experiments are carried out via Internet and Internet2 (Media), using test beds that allow remote interactions between Guest and Host that are geographically separated. All the experimental results confirm the presented theory.
- Propuesta de un modelo para el estudio de la lealtad de los clientes en el sector restaurantero(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2005-08-01) Trujillo León, María Andrea; Trujillo León, María Andrea; Arroyo López, María del Pilar Ester; Paz Carrete, Lorena de la; De Marchis Pareschi, Mario Filippo; Graciano Vera, Jorge Luis; Campus Ciudad de MéxicoEn la literatura no hay todavía un consenso sobre una definición operacional única de lealtad, ya que hasta el momento algunos autores lo han medido como recompra, mientras que otros como recomendación o preferencia. Tampoco hay una sola opinión sobre los factores y recomendaciones generales para lograrla y conservarla. De ahí la importancia de retomar este tema y abordarlo en el contexto mexicano. La presente investigación tuvo como objetivos: • Desarrollar una escala para medir lealtad basada en las propuestas recientes de la literatura. (La validación de la escala sólo se hará en el sector restaurantero) • Identificar aquellos factores que inciden en la lealtad del cliente del sector restaurantero en la zona metropolitana de Toluca • Definir diferentes categorías de restaurantes que correspondan a una mezcla relevante de factores que influya sobre las expectativas de los clientes • Determinar si los factores que inciden sobre la lealtad del cliente difieren con la categoría del restaurant El punto de partida para esta investigación es la definición de lealtad de Oliver (1999) que plantea que ésta se da en cuatro fases: cognitiva, afectiva, intencional y acción. Las hipótesis que se estudiaron fueron: • H1. Los factores de diseño de un restaurante (atributos del servicio) que conforman la base de satisfacción en los clientes tendrán un impacto mayor sobre la lealtad cognitiva, siendo menor su efecto en las dimensiones asociadas a fases más avanzadas de lealtad (afectiva, intencional, acción) • H2. El efecto de los factores de diseño de un restaurante (atributos del servicio) que conforman la base de satisfacción en los clientes tendrán un impacto diferente en las diferentes fases de lealtad dependiendo de la categoría del restaurante (ocasión, antigüedad y nivel socioeconómico) Se eligió el sector restaurantero por ser uno de los más importantes económicamente y por tener características que lo hacen interesante como la gran variedad de oferta y los pocos estudios realizados en este sector
- Préstamos basados en la relación en la interacción de los bancos y la pequeña y mediana empresa mexicana(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2005-08-01) Moya Dávila, Fernando Andrés; Moya Dávila, Fernando Andrés; Valencia Herrera, Humberto; Rao, Ramesh K.S; Isaak Dubcovsky, Gerardo Arturo; Schettino Yáñez, Macario; Campus Ciudad de MéxicoLa presente investigación estudia la relación entre bancos y pequeñas empresas mexicanas. Estudia la existencia de préstamos basados en la relación y cómo esta tecnología de créditos crea incentivos a los bancos y a la pequeña empresa para que interactúen. A través de un modelo económico, se prueba como los bancos y las pequeñas empresas están mejor construyendo una relación que no construyéndola. Si la relación no está presente, los bancos no son capaces de observar las acciones de sus deudores (pequeña empresa) y le negará cualquier cantidad de dinero adicional que le solicite si las cosas no resultan bien en sus proyectos. Por otro lado, si la relación se construye, el deudor tendrá la oportunidad de recibir dinero adicional por parte del banco si, éste último, observa que se ejerció un esfuerzo alto y por razones externas al emprendedor no pudo pagar el crédito. También, a través de un análisis empírico basado en préstamos otorgados por importante banco mexicano1 a pequeñas empresas, se estudia como el construir una relación profesional mejora las condiciones del crédito para la pequeña empresa; el costo del crédito disminuye, la probabilidad de que le pidan colateral a la pequeña empresa disminuye y también el valor del colateral requerido disminuye. Los bancos obtienen beneficios de la relación ya que la probabilidad del no pago por parte de la pequeña empresa que construyó la relación disminuye. Se desarrolla una nueva medida de relación se le llama índice de relación que incluye el tiempo de la relación, la velocidad de la relación y el límite de la relación. ¿Qué son los préstamos basados en la relación? Una firma con nexos cercanos con instituciones financieras deben de tener acceso a créditos más baratos y con mayor disponibilidad comparados con firmas sin tales nexos. Estos nexos son la relación entre el banco y la PyME. El uso de estos nexos profesionales para tener acceso a créditos (PyMEs) y el estar más seguros en otorgarlos (bancos) es la idea central de los préstamos basados en la relación. Los préstamos basados en la relación se enfocan en información cualitativa, privada y “suave” que se obtiene por el continuo contacto a través del tiempo. Los préstamos basados en la relación son la proveeduría de servicios financieros de un intermediario financiero que invierte en obtener información específica de un cliente y evalúa la rentabilidad de sus inversiones a través de múltiples interacciones con el mismo cliente en el tiempo.
- On an efficient and scalable architecture for mimicry attacks detection using probabilistic methods(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2004-11-19) Godínez Delgado, Fernando; MONROY BORJA, RAUL; 720773; Monroy Borja, Raúl; Hutter, Dieter; Giles, Lee; Nolazco, Juan A.; Mex, Carlos; Programa de Graduados en Computación, Información y Comunicaciones; Campus MonterreyAn intrusion detection system (IDS) aims at signalling an alarm for every activity that compromises a secure state of an IT system. It often amounts to detecting a known pattern of computer misuse, a deviation to ordinary, expected user behaviour, or a combination thereof. Regardless of which of these approaches is adopted, current Intrusion Detection Systems (IDSs) are easy to bypass. This thesis addresses about the three most important limitations of existing IDSs: i) current IDSs are easily overwhelmed by the the amount of information they ought to analyse; ii) current IDSs are not sufficient to monitor dynamic environments where the monitored services are changed according to the needs of the organisation; and iii) current IDSs are easy to bypass using a mimicry attack (attacks that simulate normal sequences of system calls). These kinds of attacks simulate normal activity (eg traffic, interaction) by varying an attack signature in a way that does not affect the harmfulness of the attack. Instead of creating a lightweight detection method capable of dealing with large volumes of information, at the probable cost of loss of accuracy, we focus on making intrusion detection more tractable, scalable and efficient (without compromising accuracy). We make intrusion detection more tractable by pre- processing the information. Whether it is a sequence of network packets or a sequence of system calls, the information an IDS analyses is often redundant in at least, two respects: first, every entry in the sequence may contain spurious information; second, any sequence may contain redundant subsequences. To make probabilistic intrusion detection more scalable, efficient and flexible, we propose a novel architecture that includes a service selection mechanism. Instead of analysing a single stream of data, the stream is partitioned in services, each of which is analysed by a very specialised sensor. New sensors can be added on demand; if a new service needs to be monitored another sensor is placed. To make mimicry attack intrusion detection more accurate (reduce false positives) we propose to divide attacks into smaller segments. For each segmentwe will create a detector that classifies the segment and all its variants. By combining these smaller detectors we hope to detect all variations of an attack. By using rough sets we have identified key attributes to eliminate spurious information, without missing chief details. Using n-gram theory we have identified the most redundant subsequences within a sequence, substitution of these subsequences with a fresh tag results in a reduction of the sequence length. To approach service selection, we suggest the use of hidden Markov models (HMMs), trained to detect a specific service described by a family of n-gram.s In this thesis, we introduce a method which is capable of successfully detecting a significant, interesting sub-class of mimicry attacks. The key behind our method's effectiveness lies on the use of a word network [Pereira and Riley, 1997, Young et al., 2002]. A word network conveniently decomposes a pattern matching problem into a chain of smaller, noise- tolerant pattern matchers, thereby making it more tractable and robust. A word network is realised as a finite state machine, where every state is an HMM. In our experiments, our mechanism shows an accuracy of 93%. .By contrast., the rate of false positive occurrence is only 3%. Our log reduction methods are among the best in reduction ratio and features a minimal loss of information. Ours is one of the first techniques to successfully detect a sub-class of mimicry attacks.
- Intelligent wheelchair(Tecnologico de Monterrey) Gregory Monnard Reguin, David; David Gregory Monnard ReguinThe project proposed is creating a whellchair that includes four major features. The first is being able to control the chair by moving the eyes, the second is having the possiblility of reproducing prerecorded voice messages, th thirds is being able to control the chair with voice commands and the last feature is an avoidance system based on the data collected with the ultrasonic sensors.
- Desarrollo endógeno mediante la participación ciudadana y la gestión pública local(Tecnologico de Monterrey) Villafuerte Islas, Ana; Ana Villafuerte IslasEl manejar un vehículo es una tarea que requiere de total atención por parte del conductor, tarea que demanda un nivel cognitivo alto ... Con esta tesis se pretende desarrollar una aplicación para teléfonos celulares que permita identificar cuando el usuario está manejando e intenta utilizar el celular para evitar que pueda usarlo. --Introducción h. 5.