Neural-Kalman Schemes for Non-Stationary Channel Tracking and Learning

This Thesis focuses on channel tracking in Orthogonal Frequency-Division Multiplexing (OFDM), a widely-used method of data transmission in wireless communications, when abrupt changes occur in the channel. In highly mobile applications, new dynamics appear that might make channel tracking non-stationary, e.g. channels might vary with location, and location rapidly varies with time. Simple examples might be the di erent channel dynamics a train receiver faces when it is close to a station vs. crossing a bridge vs. entering a tunnel, or a car receiver in a route that grows more tra c-dense. Some of these dynamics can be modelled as channel taps dying or being reborn, and so tap birth-death detection is of the essence. In order to improve the quality of communications, we delved into mathematical methods to detect such abrupt changes in the channel, such as the mathematical areas of Sequential Analysis/ Abrupt Change Detection and Random Set Theory (RST), as well as the engineering advances in Neural Network schemes. This knowledge helped us nd a solution to the problem of abrupt change detection by informing and inspiring the creation of low-complexity implementations for real-world channel tracking. In particular, two such novel trackers were created: the Simpli- ed Maximum A Posteriori (SMAP) and the Neural-Network-switched Kalman Filtering (NNKF) schemes. The SMAP is a computationally inexpensive, threshold-based abrupt-change detector. It applies the three following heuristics for tap birth-death detection: a) detect death if the tap gain jumps into approximately zero (memoryless detection); b) detect death if the tap gain has slowly converged into approximately zero (memory detection); c) detect birth if the tap gain is far from zero. The precise parameters for these three simple rules can be approximated with simple theoretical derivations and then ne-tuned through extensive simulations. The status detector for each tap using only these three computationally inexpensive threshold comparisons achieves an error reduction matching that of a close-to-perfect path death/birth detection, as shown in simulations. This estimator was shown to greatly reduce channel tracking error in the target Signal-to-Noise Ratio (SNR) range at a very small computational cost, thus outperforming previously known systems. The underlying RST framework for the SMAP was then extended to combined death/birth and SNR detection when SNR is dynamical and may drift. We analyzed how di erent quasi-ideal SNR detectors a ect the SMAP-enhanced Kalman tracker's performance. Simulations showed SMAP is robust to SNR drift in simulations, although it was also shown to bene t from an accurate SNR detection. The core idea behind the second novel tracker, NNKFs, is similar to the SMAP, but now the tap birth/death detection will be performed via an arti cial neuronal network (NN). Simulations show that the proposed NNKF estimator provides extremely good performance, practically identical to a detector with 100% accuracy. These proposed Neural-Kalman schemes can work as novel trackers for multipath channels, since they are robust to wide variations in the probabilities of tap birth and death. Such robustness suggests a single, low-complexity NNKF could be reusable over di erent tap indices and communication environments. Furthermore, a di erent kind of abrupt change was proposed and analyzed: energy shifts from one channel tap to adjacent taps (partial tap lateral hops). This Thesis also discusses how to model, detect and track such changes, providing a geometric justi cation for this and additional non-stationary dynamics in vehicular situations, such as road scenarios where re ections on trucks and vans are involved, or the visual appearance/disappearance of drone swarms. An extensive literature review of empirically-backed abrupt-change dynamics in channel modelling/measuring campaigns is included. For this generalized framework of abrupt channel changes that includes partial tap lateral hopping, a neural detector for lateral hops with large energy transfers is introduced. Simulation results suggest the proposed NN architecture might be a feasible lateral hop detector, suitable for integration in NNKF schemes. Finally, the newly found understanding of abrupt changes and the interactions between Kalman lters and neural networks is leveraged to analyze the neural consequences of abrupt changes and brie y sketch a novel, abrupt-change-derived stochastic model for neural intelligence, extract some neuro nancial consequences of unstereotyped abrupt dynamics, and propose a new portfolio-building mechanism in nance: Highly Leveraged Abrupt Bets Against Failing Experts (HLABAFEOs). Some communication-engineering-relevant topics, such as a Bayesian stochastic stereotyper for hopping Linear Gauss-Markov (LGM) models, are discussed in the process. The forecasting problem in the presence of expert disagreements is illustrated with a hopping LGM model and a novel structure for a Bayesian stereotyper is introduced that might eventually solve such problems through bio-inspired, neuroscienti cally-backed mechanisms, like dreaming and surprise (biological Neural-Kalman). A generalized framework for abrupt changes and expert disagreements was introduced with the novel concept of Neural-Kalman Phenomena. This Thesis suggests mathematical (Neural-Kalman Problem Category Conjecture), neuro-evolutionary and social reasons why Neural-Kalman Phenomena might exist and found signi cant evidence for their existence in the areas of neuroscience and nance. Apart from providing speci c examples, practical guidelines and historical (out)performance for some HLABAFEO investing portfolios, this multidisciplinary research suggests that a Neural- Kalman architecture for ever granular stereotyping providing a practical solution for continual learning in the presence of unstereotyped abrupt dynamics would be extremely useful in communications and other continual learning tasks.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Luis Castedo Ribas.- Secretaria: Ana García Armada.- Vocal: José Antonio Portilla Figuera

Bernard Rudofsky, desobediencia crítica a la Modernidad

Bernard Rudofsky (Moravia, 1905 – Nueva York, 1988) fue arquitecto, crítico, comisario de exposiciones, editor, diseñador de ropa y mobiliario, fotógrafo, investigador, profesor de universidades de prestigio en todo el mundo (Yale, MIT, Waseda). Creador polifacético y crítico irreverente, su figura se perfila hoy, más que nunca, como la de un creador de enorme actualidad, no sólo por su actitud crítica frente a los progresos de la sociedad de consumo, sino también por su reivindicación pionera de la economía, inteligencia y sostenibilidad de las arquitecturas anónimas del mundo, que documentó y estudió en sus viajes y publicaciones. Fue un destacado teórico del diseño, en concreto en el campo del diseño sociocultural comparativo, desarrollado en obras como The Kimono Mind, The Unfashionable Human Body o Now I lay me down to eat. A ello se le suma el profundo impacto de su actividad como comisario de provocadoras exposiciones y su labor como editor y director artístico de revistas de arquitectura y diseño de referencia como Domus, Pencil Points o Interiors. Uno de sus proyectos más influyentes fue la exposición Architecture without Architects (Arquitectura sin arquitectos), impulsada por el Museum of Modern Art de Nueva York en 1964. Bernard Rudofsky. Desobediencia crítica a la modernidad celebra el cincuenta aniversario de Arquitectura sin arquitectos, cuyo catálogo es quizás uno de los más conocidos sobre arquitectura vernácula. Sin embargo, a pesar de su proyección internacional, las ideas de Rudofsky quedaron durante su vida silenciadas por la preponderancia de los postulados modernos, más fieles a los centros académicos y al discurso de los grandes maestros. Su producción, por ello, resulta poco conocida en sus ámbitos de referencia: el diseño, el arte y la arquitectura, así como para el público en general. Desobediencia crítica a la Modernidad es el catálogo de una exposición homónima que tuvo lugar en 2014 en el Centro José Guerrero, Granada, España

An Analytical Solution for Radiofrequency Ablation with a Cooled Cylindrical Electrode

[EN] We present an analytical solution to the electrothermal mathematical model of radiofrequency ablation of biological tissue using a cooled cylindrical electrode. The solution presented here makes use of the method of separation of variables to solve the problem. Green's functions are used for the handling of nonhomogeneous terms, such as effect of electrical currents circulation and the nonhomogeneous boundary condition due to cooling at the electrode surface. The transcendental equation for determination of eigenvalues of this problem is solved using Newton's method, and the integrals that appear in the solution of the problem are obtained by Simpson's rule. The solution obtained here has the possibility of handling different functional dependencies of the source term and nonhomogeneous boundary condition. The solution provides a tool to understand the physics of the problem, as it shows how the solution depends on different parameters, to provide mathematical tools for the design of surgical procedures and to validate other modeling techniques, such as the numerical methods that are frequently used to solve the problem.This work was supported by the Universidad Autonoma de San Luis Potosi (Mexico), which granted Ricardo Romero-Mendez a sabbatical leave to do research in the field of biomedical engineering, and the Government of Spain through the "Plan Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad" (Grants TEC 2014-52383-C3-R and TEC 2014-52383-C3-1-R).Romero-Méndez, R.; Berjano, E. (2017). An Analytical Solution for Radiofrequency Ablation with a Cooled Cylindrical Electrode. Mathematical Problems in Engineering. (9021616):1-12. doi:10.1155/2017/9021616S112902161

La Casa en Frigiliana. Manifiesto rudofskiano de la domesticidad contemporánea.

La puesta en valor patrimonial y la protección de La Casa se consigue gracias a una labor continuada e intensa que culmina con su declaración como monumento en 2011. El Centro José Guerrero comienza en 2005 un papel activo en su defensa, acción a la que se sumó el Austrian Museum of Applied Contemporary Art (MAK). El Registro Andaluz de Patrimonio Contemporáneo (RAAC), redescubriría asimismo la obra rudofskiana en el marco de la investigación arquitectónica. El RAAC integra una labor de investigación crítica del discurso patrimonial aplicado a la arquitectura del Siglo XX en Andalucía y la praxis de su protección. La obra de Rudofsky ha sido la única obra propuesta para su protección como BIC (Bien de Interés Cultural) en la categoría máxima de Monumento. Su declaración como tal en 2011, sin embargo, no ha frenado las transformaciones a las que sus actuales propietarios le han sometido en los últimos años. La escala menuda de esta construcción doméstica, la fragilidad de sus valores patrimoniales y el carácter privado de la misma han dificultado la protección real de esta pieza valiosa de la historia de la arquitectura contemporánea. Su estudio pormenorizado hace posible contrastar por vez primera la documentación gráfica monográfica tanto de los fondos la Getty Research Library en Estados Unidos con toda la documentación de la Bernard Rudofsky Estate Vienna en Austria. Esta labor investigadora hace posible desvelar su propuesta integral para el habitar contemporáneo, así como su búsqueda transdisciplinar de una forma de vida plena, que trasciende la disciplina arquitectónica. Desobediencia crítica a la Modernidad es el catálogo de una exposición homónima que tuvo lugar en 2014 en el Centro José Guerrero, Granada, España

“La Casa” in Frigiliana. Rudofsky’s Manifesto of Contemporary Domesticity

The patrimonial recognition of “La Casa” and its protection have been achieved through intense, unceasing efforts culminating in its declaration as a monument in 2011. In 2005 the José Guerrero Centre began to take an active role in its defense, in which it was joined by the Austrian Museum of Applied Contemporary Art (MAk). The Andalusian Register of Contemporary Architecture (RAAC), a project of the department of Culture of the Junta de Andalucía, also rediscovered Rudofsky’s work in the context of architectonic research. The RAAC undertakes critical research of 20th century architectural heritage in Andalusia and carries out its legal protection. Within our particular research project, Rudofsky’s house has to date been the only building proposed for protection as Monument, although its declaration as such in 2011 has not halted the changes made to it in recent years by the present owners. The small scale of this domestic construction, the fragility of its patrimonial values and the fact that it is private property have all hampered the effective protection of this valuable piece of the history of contemporary architecture. detailed study has made possible the first comparison of the monographic illustrated documentation held at the Getty Research Library in uSA and all the papers at the Bernard Rudofsky Estate Vienna in Austria. This research has revealed Rudofsky’s integral proposal for contemporary living and his interdisciplinary search for a fulfilling way of life that transcends architectonic discipline. Critical Disobedience to Modernity is the catalog of an homonymous exhibition which took place in 2014 at the Centro José Guerrero, Granada, Spain

Modelos profesionales docentes. ¿Qué nos dice la investigación sobre ellos?

There are manifold contributions from educational research about the concept of professional teaching models. Particularly, in mathematics education there exist a good number of models that ultimately organize the evidence for the effective, successful and quality performance in the teaching / learning processes by the teacher.Across this work we identify patterns of evolution in research around the polyhedric concept of professional teaching model, with special attention to their behaviors in the field of mathematics education. Using techniques of science mapping, in particular the co-citation and similarity analysis (rarely explored research techniques in the field of research that concerns us), we study its dynamic complexity, and propose to read the patterns in a spiral way, that departs from the professional teaching models (theoretical and traditional) and goes to the more intimate characterization of teachers, passing through their relationship with the student, the academic community, the epistemology, and the educational system. The use of diverse methodological techniques grants trustworthiness, integrity and reliability to the research and allows not to answer only effectively to the questions under investigation but to provide with "rigour" to the intellectual exercise.Son múltiples las aportaciones realizadas en la investigación educativa alrededor del concepto de modelo competencial profesional docente. En particular, en educación matemática existe un buen número de modelos que dan cuenta, en última instancia, de la actuación efectiva, exitosa y de calidad del docente en los procesos de enseñanza/aprendizaje.A través de este trabajo identificamos patrones de evolución en investigación en torno al poliédrico concepto de modelo profesional docente, con especial atención a sus comportamientos en el ámbito de la educación matemática. Gracias a las técnicas del mapeo de la ciencia, y muy especialmente al análisis de co-citación y similitud (técnicas de investigación poco exploradas en el campo de investigación que nos ocupa), podemos aproximarnos a su dinámica complejidad y proponemos, como resultado, una lectura en espiral que parte de los modelos profesionales docentes (teórico-tradicionales) y va hasta la caracterización más íntima del docente, pasando por su relación con el estudiante, la comunidad académica, la epistemología y el propio sistema educativo.El uso de diversas técnicas metodológicas otorga integridad y conconfiabilidad a la investigación, y permite no solo responder eficazmente a las preguntas de investigación sino dotar de “rigor” al ejercicio intelectual