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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Multimodal data fusion algorithm for image classification
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-11) Beder Sabag, Taleb; Vargas Rosales, César; emipsanchez; Pérez García, Benjamín de Jesús; School of Engineering and Sciences; Campus Monterrey
IImage classification algorithms are a tool that can be implemented on a variety of research sectors, some of these researches need an extensive amount of data for the model to obtain appropriate results. A work around this problem is to implement a multimodal data fusion algorithm, a model that utilizes data from different acquisition frameworks to complement for the missing data. In this paper, we discuss about the generation of a CNN model for image classification using transfer learning from three types of architectures in order to compare their results and use the best model, we also implement a Spatial Pyramid Pooling layer to be able to use images with varying dimensions. The model is then tested on three uni-modal data-sets to analyze its performance and tune the hyperparameters of the model according to the results. Then we use the optimized architecture and hyperparameters to train a model on a multimodal data-set. The aim of this thesis is to generate a multimodal image classification model that can be used by researchers and people that need to analyze images for their own cause, avoiding the need to implement a model for a specific study.
Constructing a Statistical Behavior Management Scheme for Aggregate Interference in Cognitive Radio Sensor Networks
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-15) Ornelas Gutiérrez, Angel; Vargas Rosales, César; RR/tolmquevedo; Azpilicueta Fernández de las Heras, Leyre; School of Engineering and Sciences; Campus Monterrey; Villalpando Hernández, Rafaela
This research work aims to provide design recommendations to manage aggregate interference generated in cognitive radio sensor networks to account for different scenarios. Previous studies have analyzed the statistical behavior of aggregate interference in conventional wireless networks and cognitive radio networks for specific scenarios. However, the behavior of the aggregate interference presents severe challenges in the cognitive radio networks for several scenarios in which it is required to have a design scheme that allows making operational decisions of the network to mitigate or manage such interference. The question arises, how aggregate interference behaves in different scenarios of cognitive radio sensor networks? Moreover, how could a designer of this kind of network handle aggregate interference knowing its behavior? The methodology for answering these questions consists on the development of computational simulations to generate scenarios with distinct parameters that account for variations in the number of users and distinct protection radii for primary receivers of the cognitive networks. Carry out an analysis and statistical modeling of the data obtained and synthesize the results to construct a scheme that helps to handle the aggregate interference. The constructed management scheme shows parameters in which the aggregate interference can be modeled as a heavy-tailed, light-tailed, exponential or Gaussian distribution and, therefore, use that distribution for mitigation methods, or avoid parameters in which extreme values of interference are presented. This work also shows the significance of the most contributing interference nodes in the network to model the aggregate interference with just the most contributing interferers in the network. Furthermore, how the statistical behaviors of interference are affected by the integration of a discrete power control is discussed. The contribution of this study is that it discusses how a cognitive radio sensor network designer could control parameters such as the primary user protection radius to approach for the optimal operation of its network concerning the aggregate interference statistical characteristics.
Volumetric bioprinting for medical applications
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-05) López Franco, Arturo; VARGAS ROSALES, CESAR; 33901; Vargas Rosales, César; RR; Zhang, Yu Shrike; School of Engineering and Sciences; Campus Monterrey; Galaviz Aguilar, José Alejandro
Additive manufacturing (3D printing) has been a widely used tool in a lot of different industries. Among these industries can be found tissue engineering and regenerative medicine, since bioprinting is one of the main techniques applied. The implementations of new technologies for additive manufacturing, have been adapted into the bioprinting area for medical purposes. Additive manufacturing technologies have been evolving from printing point-to-point, layer-by-layer, and more recently volumetric printing, which represents printing a whole volume simultaneously. In this thesis is presented a new technique for bioprinting, the Computed Axial Lithography (CAL) printing, which is a recently additive manufacturing technology based on reconstruct- ing a volume simultaneously, has demonstrated to have advantages against other additive manufacturing techniques, improving the printing speed, the resolution, minimum material waste, and more, and its application in the medicine industry has not been explorer looking very promising for this research field with limitless applications. The bioink used in the experiments presented is a GelMA-based hydrogel, and the 3D structures achieved should be capable of present biocompatibility with living organisms. For this thesis, the reproduction of the CAL printing for biomaterials, in this particular case GelMA, is proved, opening the doors for applying the same concept to different biomaterials, which could have limitless applications in many distinct research areas.
(Enabling) Roaming management in GPRS and WLAN networks based on SIP
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2010-02-01) Rosas Mendieta, Dulce Selene; Vargas Rosales, César; Castañón Ávila, Gerardo Antonio; Muñoz Rodríguez, David; Rodríguez Cruz, José Ramón; Programa de Graduados de la División de Mecatrónica y Tecnologías de la Información; Campus Monterrey
Wireless networks technologies put focus on mobility management and transparent connectivity when user roams. These technologies must be integrated in a single environment based on All‐IP networks. Thus, mobile users could be able to visit and connect any heterogeneous networks technologies. Unfortunately, technical issues and the lack of roaming agreements between the different networks operators avoid the transparent interoperability. Our work is based on compare and analyze two roaming approaches in order to integrate communication and session control between two different networks technologies. We examine solutions based on loose coupled integration and IP mobility, which provide mobile applications (multimedia IP) and mobile services (AAA functions and user profiles). The approaches are based on the classification for service composition of the SAHARA project [39]: 1) Cooperative Model and 2) Brokered Model. Both models depend on the Service Level Agreements (SLAs), which represent a low cost and fast time‐to‐market [14]. The main goal consists to compare both models in the Next Generation Networks (NGN) that enable roaming management and session control from GPRS to WLAN, using SIP signaling and following the same principles, conditions and assumptions.
Propuesta de seguridad para el protocolo BGP en el atributo AS_PATH
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2009-12-01) Ramírez Juárez, José Paulino; Vargas Rosales, César; tolmquevedo; Tecnológico de Monterrey, Campus Monterrey
En el ruteo interdominio existen muchos ataques al protocolo BGP, lo cual ha llevado a plantear varias propuestas de seguridad. Estas propuestas son difíciles de implementar en la red debido a los costos computacionales que se requieren para desplegarlas a través de toda la Internet. En esta tesis se propone un nuevo mecanismo de verificación de ruta en el atributo AS_PATH, el cual consiste de un ping de verificación que se realizara cuando una nueva ruta llegue a través de un mensaje de UPDATE. Ya que el comando ping es un paquete muy pequeño, no requiere de grandes recursos computacionales y ademá}s su implementación es relativamente sencilla.
"Una Metodología para la Selección de Tecnologías en Redes Industriales"-Edición Única
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2007-12-01) Aranda de la Garza, Gilberto René; Vargas Rosales, César; Campuzano Treviño, Gabriel; Castañon Ávila, Gerardo A.; Campus Monterrey; Dieck Assad, Graciano
En estos últimos años la creación de nueva tecnología se ha dado a pasos muy acelerados por ella la necesidad de una metodología para seleccionarla es necesaria en todas las diferentes disciplinas. En el presente trabajo se desarrolla una metodología para seleccionar tecnología que involucra las disciplinas de telecomunicaciones, automatización y electrónica.
On power law reachability analysis at an autonomous system granularity
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2007-07-01) Magaña Rodríguez, Roberto Enrique; MAGAÑA RODRIGUEZ, ROBERTO ENRIQUE; 179239; Vargas Rosales, César; Castañón Ávila, Gerardo; Aguilar Coutiño, Artemio; ITESM-Campus Monterrey; Dieck Assad, Graciano
The internet consists of rapidly increasing number of Autonomous Systems(AS) interconnected. Interdomain routing in Internet is coordinated by the Border Gateway Protocol. Which routing table has been growing dramatically. This situation lead us to search a new routing scheme able to support the new requirements. Since each AS administers its reachability information via routing policies, the new routing scheme must consider the reachability of the nodes into the network. These routing policies are constrained by the contractual commercial agreements between ASes. This implies that the relationships among Autonomous System granularity (i.e. Customer-Provider) are an important aspect of Internet structure and affects the reachability of the nodes in the network topology. In this work, we explore the relationship between the times between topology changes in the AS-Level and the reachability over a network based in a customer-provider relationship to characterize the reachability process. We begin with a network generator based in the nodes at 1 hop distance, followed by a routing algorithm to find the shortest path to all available destinations from a particular origin. Afterwards, we run a simulation modifying the reachability state of the nodes over time. We shown that the decrease of reachable Autonomous Systems between topology changes in the nodes obeys a power law distribution that is consequence of the power law observed in the times between topology changes at the interdomain level.
On Reachability of Autonomous Systems Based on Announcements Changes -Edición Única
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2007-07-01) León Castelán, Jorge Alberto; Vargas Rosales, César; Rodríguez Cruz, José Ramón; Mex Perera, Jorge Carlos; ITESM-Campus Monterrey; Dieck Assad, Graciano
In this work data obtained from interdomain routing protocol (IDR) is used to obtain statistical analysis of Autonomous Systems using the protocol. With the statistical description we observe the reachability of three AS belonging to the Internet core and its three most active links. We also calculate the updates and withdrawals to monitor the changes observed in the three AS from the interdomain protocol. This monitoring led us to find a ratio around 1 for updates and withdrawals, this could be taken into consideration for detecting anomalies in the interdomain routing protocol. The creation of solutions for such anomalies is out of the scope of this work
Comunicación Simultánea Multiusuario: Un Sistema DS-CDMA de Radio Cognitiva-Edición Única
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2007-05-01) Barrera Suárez, Carlos; Vargas Rosales, César; Rodríguez Cruz, José Ramón; Aguilar Coutiño, Artemio; ITESM-Campus Monterrey; Dieck., Assad Graciano
“En muchas bandas de radio frecuencia, el acceso al espectro es un problema más significativo que la limitación física del mismo, es debido en gran parte a la regulación del comando-y-control que limita la capacidad de los usuarios potenciales de espectro de obtener dicho acceso”, [1]. De hecho, si exploramos porciones del espectro de radio frecuencia, [2], encontraremos que [3–5] 1. Algunas bandas en el espectro de radio frecuencias, en su mayoría se encuentran desocupadas la mayor parte del tiempo. 2. Algunas otras frecuencias son ocupadas parcialmente. 3. Las bandas de frecuencia restantes son exageradamente utilizadas. La radio cognitiva es un sistema de comunicación inalámbrica que esta alerta de su ambiente circundante, y utiliza el proceso de entender-por-construir para aprender del ambiente y adaptar sus estados internos dependiendo de las variaciones estadística de la estimulación por radio frecuencia, haciendo sus respectivos cambios en ciertos parámetros de operación (por ejemplo, potencia de transmisión, frecuencia de la portadora, y estrategia de modulación) en tiempo real, con dos objetivos principales, [2]: Comunicación altamente confiable donde sea y cuando sea necesaria. Utilización eficiente del espectro de radio frecuencia. En este trabajo nos enfocamos principalmente en que varios usuarios se puedan comunicar simultáneamente en un escenario ad hoc, con el fin de utilizar al máximo el espectro de radio frecuencias, pero además de ofrecer un nuevo sistema de comunicación DS-CDMA que sea capaz mitigar o disminuir los problemas que existen en un canal inalámbrico, tales como: la interferencia de acceso múltiple, la terminal escondida y la terminal expuesta, entre otros.
On power law relationships of IDR changes
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2006-12-01) Gómez Zamorano, Jesus Rubén; Vargas Rosales, César; ITESM
In this work data obtained from an interdomain routing protocol (IDR) is used to create a topology map of the network in the interdomain level. With the statistical description of the obtained topology, power law relationships are observed for the times between the changes in the number of routes in interdomain level links. These power law relationships are explained in terms of the power law relationships observed in the interdomain level topology. With this new information, the scalability issues (i.e. Internet growth) and security proposals for interdomain routing can be further analyzed with a different scope. The creation of a new protocol or the creation of new techniques and algorithms that increase the performance of the existing protocols (either already approved or in development in other publications) is out of the scope of this work.

Ciencias Exactas y Ciencias de la Salud

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