Algunos aspectos de controlabilidad para ecuaciones parabólicas e hiperbólicas no lineales

Descargue el texto completo en el repositorio institucional de la Universidad Federal Fluminense: https://app.uff.br/riuff/handle/1/12750El objetivo de este trabajo es el estudio teórico del control en ecuaciones de tipo parabólico e hiperbólico no lineales. Primero, tenemos el estudio del control nulo de un sistema de turbulencia con un acoplamiento de tipo Boussinesq, aquí disminuimos el número de controles escalares sobre un dominio arbitrario. Segundo, tenemos el estudio del control local nulo de un sistema parabólico no lineal unidimensional. Tercero, tenemos el estudio del control jerárquico de una ecuación de tipo calor con no linealidades en el término de difusión. Aquí aplicamos las estrategias de Stackelberg-Nash. Por último, tenemos el estudio del control exacto en una ecuación de onda con no linealidades de tipo no local.O objetivo principal desta tese é o estudo teórico do controle nas equações do tipo parabólico e hiperbólico não lineares, temos por exemplo o estudo do controle nulo de um sistema com turbulência e acoplamento do tipo boussinesq. Neste caso vamos diminuir a quantidade de controles escalares e trabalhar sobre um domínio arbitrário. Também vamos a estudar a controlabilidade local nula de um sistema parabólico no linear unidimensional. Temos por outro lado, o estudo do controle hierárquico de uma equação do tipo calor com não linearidades no termo de difução. Aqui vamos aplicar as estratégias do tipo Stackelberg-Nash para resolver o problema. Por último estudaremos a controlabilidade exata de uma equação hiperbólica com não linearidades não locais.Brasil. Ministério da Educação. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes

Adherence of model molecules to silica surfaces: first principle calculations

The adherence of model molecules to  crystal SiO2 surfaces is studied from first principle calculations at the DFT level. Adsorption energies are calculated which follow the experimental threads obtained elsewhere (Rivera et al.,2013). We study the quantum nature of the electronic charge transfer between the surface and the molecules, showing the localized and delocalized patterns associated to the repulsive and attractive case respectively.Fil: Nuñez, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo; Argentina. Comision Nacional de Energia Atomica. Gerencia del Area de Investigaciones y Aplicaciones no Nucleares. Gerencia de Fisica (CAB); ArgentinaFil: Prado, Miguel Oscar. Comision Nacional de Energia Atomica. Gerencia del Area de Investigaciones y Aplicaciones no Nucleares. Gerencia de Fisica (CAB); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentin

Insensitizing controls for a quasi-linear parabolic equation with diffusion depending on gradient of the state

In this paper, a quasi-linear parabolic equation with a diffusion term dependent on the gradient to the state with Dirichlet boundary conditions is considered. The goal of this paper is to prove the existence of control that insensitizes the system under study which is the case that Xu Liu left open in 2012. It is well known that the insensitizing control problem is equivalent to a null controllability result for a cascade system, which is obtained by duality arguments, Carleman estimates, and the Right Inverse mapping theorem. Also, some possible extensions and open problems concerning other quasi-linear systems are presented

Adherence of Molecules to Silica Glass Surface: Experimental Results and Theoretical Calculations

The adherence of molecules to surfaces is used in a wide scope of technological applications. In this work we study the attachment of molecules onto porous silica glass surface obtained from a Vycor glass, after glassglass phase separation and leaching of the soluble phase with water. Nitrogen adsorption at 77 K was used for the determination of the specific surface area (BET area) and pore size distribution on the leached glass. The adherence onto the glass surface, of model molecules methylene blue (MB) and eosine yellow (EY), with positive and negative electrical charges respectively, was studied. The adsorption kinetics was determined from aqueous solutions using UV-VIS spectroscopy. It was found that the silica glass surface as prepared in of glass was found for methylene blue, and almost null adsorption for eosine yellow. First principles calculations were performed using the Density Functional Theory in order to model the interaction between both molecules and the glass surface.Fil: Rivera Figueroa, Edison. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Prado, Miguel Oscar. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentina. Comision Nacional de Energia Atomica. Centro Atomico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nuñez, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comision Nacional de Energia Atomica. Centro Atomico Bariloche; Argentina. Universidad Nacional de Cuyo; Argentin

FORTALECIMIENTO DEL ACOMPAÑAMIENTO, SEGUIMIENTO Y CONTROL DE LOS ESTUDIANTES EN SUS PROCESOS ACADÉMICOS UNIDAD DOCENTE BÀSICA (UDB) – MATEMÁTICA – DEPARTAMENTO DE CIENCIAS BÁSICAS DE LA FACULTAD REGIONAL BUENOS AIRES DE LA UNIVERSIDAD TECNOLÓGICA NACIONAL

Los alumnos que ingresan a la Universidad acceden a la misma careciendo de las capacidades necesarias para poder insertarse, sin mayores dificultades, en el nivel superior de enseñanza. Este objetivo de este trabajo de investigación - acción está centrado en la implementación de la tutoría como estrategia de intervención en el proceso de aprendizaje de los alumnos, ya que constituye una acción educativa que permite el seguimiento tanto individual como grupal en el proceso de formación integral de los alumnos, así como el desarrollo de estrategias dirigidas a estimular la conciencia de habilidades y destrezas de los estudiantes con la finalidad, entre otras, de adquirir eficiencia en su nivel académico y aumentar la retención. El proceso de investigación está aportando conocimiento nuevo a los ya existentes en el área de acción tutorial –presencial- en la universidad, en tanto que los resultados obtenidos permitirán efectuar pronósticos sobre el comportamiento y la actitud del estudiante ingresante a la universidad frente al impacto de un régimen y habito de estudio nuevo para él. Las conclusiones obtenidas podrán ser consideradas antecedentes valiosos para la confección y/o ajustes de nuevos diseños curriculares, centrados en los tiempos de aprendizaje del alumno y su estado formativo inicial con el que enfrenta los nuevos procesos de aprendizaje – enseñanza en la universidad

A dose-volume histogram based decision-support system for dosimetric comparison of radiotherapy treatment plans

Background: The choice of any radiotherapy treatment plan is usually made after the evaluation of a few preliminary isodose distributions obtained from different beam configurations. Despite considerable advances in planning techniques, such final decision remains a challenging task that would greatly benefit from efficient and reliable assessment tools. Methods: For any dosimetric plan considered, data on dose-volume histograms supplied by treatment planning systems are used to provide estimates on planning target coverage as well as on sparing of organs at risk and the remaining healthy tissue. These partial metrics are then combined into a dose distribution index (DDI), which provides a unified, easy-to-read score for each competing radiotherapy plan. To assess the performance of the proposed scoring system, DDI figures for fifty brain cancer patients were retrospectively evaluated. Patients were divided in three groups depending on tumor location and malignancy. For each patient, three tentative plans were designed and recorded during planning, one of which was eventually selected for treatment. We thus were able to compare the plans with better DDI scores and those actually delivered. Results: When planning target coverage and organs at risk sparing are considered as equally important, the tentative plan with the highest DDI score is shown to coincide with that actually delivered in 32 of the 50 patients considered. In 15 (respectively 3) of the remaining 18 cases, the plan with highest DDI value still coincides with that actually selected, provided that organs at risk sparing is given higher priority (respectively, lower priority) than target coverage. Conclusions: DDI provides a straightforward and non-subjective tool for dosimetric comparison of tentative radiotherapy plans. In particular, DDI readily quantifies differences among competing plans with similar-looking dose-volume histograms and can be easily implemented for any tumor type and localization, irrespective of the planning system and irradiation technique considered. Moreover, DDI permits to estimate the dosimetry impact of different priorities being assigned to sparing of organs at risk or to better target coverag

Traditional education vs modern education. What is the impact of teaching techniques' evolution on students learning process?

The main objective of this article is to focus on the analysis of teaching techniques, ranging from the use of the blackboard and chalk in old traditional classes, using slides and overhead projectors in the eighties and use of presentation software in the nineties, to the video, electronic board and network resources nowadays. Furthermore, all the aforementioned, is viewed under the different mentalities in which the teacher conditions the student using the new teaching technique, improving soft skills but maybe leading either to encouragement or disinterest, and including the lack of educational knowledge consolidation at scientific, technology and specific levels. In the same way, we study the process of adaptation required for teachers, the differences in the processes of information transfer and education towards the student, and even the existence of teachers who are not any longer appealed by their work due which has become much simpler due to new technologies and the greater ease in the development of classes due to the criteria described on the new Grade Programs adopted by the European Higher Education Area. Moreover, it is also intended to understand the evolution of students’ profiles, from the eighties to present time, in order to understand certain attitudes, behaviours, accomplishments and acknowledgements acquired over the semesters within the degree Programs. As an Educational Innovation Group, another key question also arises. What will be the learning techniques in the future?. How these evolving matters will affect both positively and negatively on the mentality, attitude, behaviour, learning, achievement of goals and satisfaction levels of all elements involved in universities’ education? Clearly, this evolution from chalk to the electronic board, the three-dimensional view of our works and their sequence, greatly facilitates the understanding and adaptation later on to the business world, but does not answer to the unknowns regarding the knowledge and the full development of achievement’s indicators in basic skills of a degree. This is the underlying question which steers the roots of the presented research

The history of technology in education. A comparative study and forecast

Area, launched in 1999 with the Bologna Declaration, has bestowed such a magnitude and unprecedented agility to the transformation process undertaken by European universities. However, the change has been more profound and drastic with regards to the use of new technologies both inside and outside the classroom. This article focuses on the study and analysis of the technology’s history within the university education and its impact on teachers, students and teaching methods. All the elements that have been significant and innovative throughout the history inside the teaching process have been analyzed, from the use of blackboard and chalk during lectures, the use of slide projectors and transparent slides, to the use of electronic whiteboards and Internet nowadays. The study is complemented with two types of surveys that have been performed among teachers and students during the school years 1999 - 2011 in the School of Civil Engineering at the Polytechnic University of Madrid. The pros and cons of each of the techniques and methodologies used in the learning process over the last decades are described, unfolding how they have affected the teacher, who has evolved from writing on a whiteboard to project onto a screen, the student, who has evolved from taking handwritten notes to download information or search the Internet, and the educational process, that has evolved from the lecture to acollaborative learning and project-based learning. It is unknown how the process of learning will evolve in the future, but we do know the consequences that some of the multimedia technologies are having on teachers, students and the learning process. It is our goal as teachers to keep ourselves up to date, in order to offer the student adequate technical content, while providing proper motivation through the use of new technologies. The study provides a forecast in the evolution of multimedia within the classroom and the renewal of the education process, which in our view, will set the basis for future learning process within the context of this new interactive era