Polyp Localization and Segmentation in Colonoscopy Images by Means of a Model of Appearance for Polyps

Advisor/s: F. Javier Sánchez, Fernando Vilariño. Date and location of PhD thesis defense: 17 December 2012, Autonomous University of Barcelona.Colorectal cancer is the fourth most common cause of cancer death worldwide and its survival rate depends on the stage in which it is detected on hence the necessity for an early colon screening. There are several screening techniques but colonoscopy is still nowadays the gold standard, although it has some drawbacks such as the miss rate. Our contribution, in the field of intelligent systems for colonoscopy, aims at providing a polyp localization and a polyp segmentation system based on a model of appearance for polyps. To develop both methods we define a model of appearance for polyps, which describes a polyp as enclosed by intensity valleys. The novelty of our contribution resides on the fact that we include in our model aspects of the image formation and we also consider the presence of other elements from the endoluminal scene such as specular highlights and blood vessels, which have an impact on the performance of our methods. In order to develop our polyp localization method we accumulate valley information in order to generate energy maps, which are also used to guide the polyp segmentation. Our methods achieve promising results in polyp localization and segmentation. As we want to explore the usability of our methods we present a comparative analysis between physicians fixations obtained via an eye tracking device and our polyp localization method. The results show that our method is indistinguishable to novice physicians although it is far from expert physicians

Effects of globalization in small and medium enterprises (smes)

Las pequeñas y medianas empresas representan uno de los sectores económicos que captan el gran interés por los países del mundo, todos los proyectos, los organismos internacionales y regionales, y los investigadores en función de la evolución y los cambios de la economía mundial, debido al papel central en la producción, el empleo y la generación de ingresos, la innovación y el progreso tecnológico, así como su desempeño en la consecución de los objetivos económicos y sociales para todas las naciones. Pero hay que señalar que la situación actual del desarrollo económico en los países en desarrollo, tasas de empeoramiento y bajo crecimiento, son factores de los cuales se aprovechan los países desarrollados para alcanzar un alto nivel de desarrollo económico a través de las políticas de expansión empresarial. Ahora bien, las tendencias del nivel económico moderno nos llevaron a arrojar luz sobre las pequeñas y medianas empresas en los países en desarrollo, con todos los obstáculos que enfrenta este tipo de instituciones, con énfasis en el rol que en últimas juegan las organizaciones no gubernamentales en la financiación de la actividad económica. Desde esta perspectiva, se nota que la globalización va más allá del suelo territorial y administrativo de los países o las naciones, va más allá del estado físico o fronteras de la nación; “la palabra globalización vienen a la mente cada vez que hablamos de desarrollo masivo de las comunicaciones y la información, el espacio de internet y la tecnología” (La Desaparición de la Soberanía, la Publicación y Distribución, Amman 1994 p. 38).Small and medium enterprises represent one of the economic sectors that capture the great interest in the world, all projects, international and regional organizations, and researchers in light of developments and changes in the global economy due to its central role in production, employment and income generation, innovation and technological progress and its role in achieving economic and social goals for all nations. But it should be noted that the current situation of economic development in developing countries, worsening rates and low growth are the factors which developed countries are harnessed to achieve a high level of economic development through business expansion policies. However, the level of modern economic trends led us to shed light on small and medium enterprises in developing countries, with all the obstacles facing such institutions, with emphasis on the role that ultimately played by non-governmental organizations in the financing of economic activity. From this perspective, we note that globalization goes beyond the territorial and administrative floor of the countries or nations, it goes beyond the physical borders of the state or nation; "The word globalization come to mind whenever we talk of massive development of communication and information, the Internet space and technology" (La Desaparición de la Soberanía, la Publicación y Distribución, Amman 1994 p. 38)

A family of Lyapunov-based control schemes for maximum power point tracking in buck converters

summary:This paper presents a novel family of Lyapunov-based controllers for the maximum power point tracking problem in the buck converter case. The solar power generation system here considered is composed by a stand-alone photovoltaic panel connected to a DC/DC buck converter. Lyapunov function candidates depending on the output are considered to develop conditions which, in some cases, can be expressed as linear matrix inequalities; these conditions guarantee that the output goes asymptotically to zero, thus implying that the MPPT is achieved. Simulation and real-time results are presented, which validate the effectiveness of the proposals

Product placement: a theoretical-practical review of its capabilities and limitations

El product placement (la técnica publicitaria consistente en emplazar marcas dentro de películas, teleseries y otros medios) ha crecido enormemente en las últimas décadas y cuenta con unas expectativas de crecimiento muy halagüeñas para el futuro. Este artículo revisa el modelo de persuasión narrativa, que es un marco conceptual muy adecuado para entender por qué el cine y la televisión son capaces de modificar las creencias, intenciones y conductas del público y, más en particular, por qué el product placement es capaz de hacer que el público recuerde las marcas emplazadas, cambie de actitud hacia ellas e incluso acabe consumiéndolas. Este artículo también revisa cómo las productoras de cine/televisión, las agencias de publicidad/medios y los anunciantes se organizan en la práctica para gestionar que las marcas sean emplazadas en películas y teleseries. Además se analizan las ventajas, inconvenientes, oportunidades y amenazas que el product placement tiene en la actualidad, especialmente cuando se compara con la publicidad convencional. Una evaluación global de toda esta información permite concluir que el product placement es una técnica con mejores expectativas que la publicidad convencional para aquellas empresas que no disponen de los recursos de las grandes multinacionales pero que sí aspiran a penetrar efectivamente en los mercados internacionales

Use of Software Tools for Real-time Monitoring of Learning Processes: Application to Compilers subject

[EN] The effective implementation of the Higher European Education Area has meant a change regarding the focus of the learning process, being now the student at its very center. This shift of focus requires a strong involvement and fluent communication between teachers and students to succeed. Considering the difficulties associated to motivate students to take a more active role in the learning process, we explore how the use of a software tool can help both actors to improve the learning experience. We present a tool that can help students to obtain instantaneous feedback with respect to their progress in the subject as well as providing teachers with useful information about the evolution of knowledge acquisition with respect to each of the subject areas. We compare the performance achieved by students in two academic years: results show an improvement in overall performance which, after observing graphs provided by our tool, can be associated to an increase in students interest in the subject.This work has been supported by two teaching innovation projects awarded by Oficina de Qualitat Docent de la Universitat Autònoma de Barcelona (“Empleo de herramientas informáticas para monitorizar el proceso de aprendizaje en la asignatura Compiladors “ and “Análisis en tiempo real de resultados de aprendizaje obtenidos mediante herramientas de autoevaluación: Aplicación en la asignatura Compiladors”.http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Sánchez, FJ.; Bernal, J. (2018). Use of Software Tools for Real-time Monitoring of Learning Processes: Application to Compilers subject. Editorial Universitat Politècnica de València. 1359-1366. https://doi.org/10.4995/HEAD18.2018.8205OCS1359136

Analysis and preconditioning of a probabilistic domain decomposition algorithm for elliptic boundary value problems

PDDSparse is a new hybrid parallelisation scheme for solving large-scale elliptic boundary value problems on supercomputers, which can be described as a Feynman-Kac formula for domain decomposition. At its core lies a stochastic linear, sparse system for the solutions on the interfaces, whose entries are generated via Monte Carlo simulations. Assuming small statistical errors, we show that the random system matrix ${\tilde G}(\omega)$ is near a nonsingular M-matrix $G$, i.e. ${\tilde G}(\omega)+E=G$ where $||E||/||G||$ is small. Using nonstandard arguments, we bound $||G^{-1}||$ and the condition number of $G$, showing that both of them grow moderately with the degrees of freedom of the discretisation. Moreover, the truncated Neumann series of $G^{-1}$ -- which is straightforward to calculate -- is the basis for an excellent preconditioner for ${\tilde G}(\omega)$. These findings are supported by numerical evidence

Comportamiento hidráulico de un sistema humedal-construido/tanque-rRegulador para aprovechamiento de aguas lluvias en el campus de la Pontificia Universidad Javeriana sede Bogotá

El aprovechamiento de aguas lluvias es un concepto que en los últimos años ha incrementado su popularidad, no solo por la rentabilidad económica que estas técnicas brindan a los usuarios, sino por la concientización masiva naciente en el planeta sobre la conservación de los recursos hídricos (C A Booth et al. 2003), por lo cual, es importante comprender que el agua captada tiene múltiples usos y beneficios enfocados a la conservación del medio ambiente y al mejoramiento de la salud pública, ayudando a la rehabilitación de suelos, paisajismo y como fuente alternativa de agua potable. Este articulo presenta una descripción del comportamiento hidráulico de un sistema Humedal-Construido/Tanque-Regulador utilizado como componente del sistema de aprovechamiento de aguas lluvias de la PUJB, en el cual se buscó hacer la caracterización del funcionamiento hidráulico del sistema antes mencionado durante un evento de lluvia, lo que permitió realizar la verificación de principios de diseño hidrológico e hidráulico del sistema a la luz de los resultados medidos en campo, empleando como variable de calibración los coeficientes de escorrentía y de descarga para generar un modelo lluvia-escorrentía teórico, con el cual fue posible hacer una comparación y una optimización del mismo. Los resultados sugieren que las variaciones del método de calibración no influyen en los resultados obtenidos, pero permiten ver la importancia de la calibración del modelo planteado para futuros estudios.In the last years a new attitude towards the rainwater usage is becoming more frequently, not only for the economic benefits this technique brings to the users but the new growing mass awareness about the conservation of water resources (C A Booth et al. 2003), whereby, is important to understand that the collected waters have different kind of uses and benefits all of them focused to the environmental conservation and the improvement of public health, helping the soil improvement, landscaping and as an alternative source of potable water. This paper describes the hydraulic behavior of a Contructed- wetland/Reservoir- tank used as a component of the rainwater collection system from PUJB during a raining event, allowing verification of hydrologic and hydraulic principles of this system in accordance with the gotten field results, using as calibration variable, all the runoff and discharge coefficients in order to create a rain-runoff theorist model, with these results a comparison and optimization of this model was made. The results, suggest that the variations of the calibration method do not affect the gotten results. Also, it let us understand how important is the calibration of the working model for the next researches.Ingeniero (a) CivilPregrad

To brand or not to brand a product placement? Evidence from a field study of two influence mechanisms of positive portrayals of alcohol in film

This is the pre-peer reviewed version of the following article: To brand or not to brand a product placement? Evidence from a field study of two influence mechanisms of positive portrayals of alcohol in film, which has been published in final form at http://doi.org/10.1111/dar.12671. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versionns"Introduction and Aims: We propose that branded and non-branded product placements in movies are interpreted differently and that a movie with unbranded alcohol portrayals influences audiences’ alcohol-related beliefs and choices indirectly, through the process of narrative transportation, whereas a movie with branded alcohol placements impacts audiences’ alcohol beliefs and choices via a more basic social-cognitive process of influence. Design and Methods: Ordinary moviegoers (N = 758) attended a showing of The Snows of Kilimanjaro (2011) in a popular theatre in Tacna, Peru. Subjects were randomly assigned to watch the original movie, with branded alcohol portrayals, or a brand-free, control version. Reactions to the movie and alcohol-related beliefs were collected in a survey immediately after the film exposure and real beverage choices were measured. Results: The findings reveal that exposure to unbranded positive portrayals of alcohol produces story-consistent beliefs and alcohol choices through the process of narrative transportation and that exposure to branded positive alcohol portrayals produces direct effects in terms of alcohol expectancies and brand choice, despite lowering narrative transportation. Although viewers disengage more from the characters, and experience lesser enjoyment and perceived realism when exposed to actual brands in a movie, they still hold positive alcohol expectancies and are more likely to select the placed brand, a process consistent with social cognitive theory. Discussion and Conclusions: The findings suggest caution about the recommended policy of removing branding from alcohol placements, such as in the case with plain packaging in tobacco, and instead call for effective policies to constrain alcohol product placement, as was done with tobacco placements.The authors wish to thank the Universidad de Tarapacá (Arica, Chile) for financially supporting the field research under Major Project No. 8745–1