La matemática como herramienta de modelización para dar respuesta a situaciones problema

Se presenta un avance de un proyecto de trabajo docente que tiene como objetivo implementar un recorrido de estudio e investigación en la carrera de químico biológicas. Se abordan algunas modificaciones que se han propuesto a los procesos de enseñanza y aprendizaje desde la perspectiva de la resolución de situaciones problema. Se plantea lo útil que puede ser la modelización para resolver problemas del área de ciencias químico-biológicas, mediante el uso del cálculo, en la Universidad de Sonora. Se resalta la importancia de contar con la teoría antropológica de lo didáctico como el marco teórico de referencia, al mismo tiempo, se recomienda iniciar la transformación del proceso pedagógico, para darle respuesta a uno de los problemas mayores de la matemática planteado por Freudenthal

Inspección y análisis científico de las torres atalaya que defendieron el último reino islámico de la Península Ibérica

The Islamic Nasrid kingdom of Granada occupied the mountainous areas of the south-eastern area of the Iberian Peninsula. The Baetic mountain range worked as a natural frontier between the Nasrid kingdom and the Christian kingdom of Castile from 1232 to 1492. An extensive network of watchtowers was built by Nasrid to control this frontier stablishing visual communication between them and the Nasrid centre at the Alhambra citadel. Many of them are still standing, disperse through the provinces of Granada, Malaga, Almeria and the eastern parts of Jaen, Cordoba and Cadiz. Even being this military architecture protected by Spanish Heritage law, many of these medieval towers and their cultural landscapes are in severe risk. There are studies of individual towers, but any global comparative study has been developed. For this reason, within the framework of the R&D project called ‘Las atalayas que defendieron el reino nazarí de Granada. Análisis y documentación científica (Nazalaya)” (HAR2016-79689-P) financed by the Ministry of Economy, Industry and Competitiveness of Spain, the towers are being studied as individual exemplars as well as components of the same typological group. This generates a complete documentation constituted by a homogenous and exhaustively planimetry which supplements the existing information and enabling comparative analysis. Furthermore complete architectural surveys are being carried out using techniques as photogrammetry. In addition to the analysis of construction systems, the structural safety of these towers is evaluated formulating guidelines for its restoration.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto del Plan Nacional I+D+i (Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia) entitled ‘Las atalayas que defendieron el reino nazarí de Granada. Análisis y documentación científica (Nazalaya)’ (HAR2016-79689-P) Proyecto de Investigación Precompetitivo (mod. A) del Plan Propio de la Universidad de Málaga ‘La construcción de un paisaje: arquitectura de tapial en la Alta Andalucía en el siglo XIII. Estudio y análisis del sistema de torres andalusíes en el valle de Segura de la Sierra’ X Convocatoria de Proyectos de Investigación de la Fundación Pública Andaluza Centro de Estudios Andaluces en la modalidad de proyectos individuales, PRY/259/17 ‘Torres medievales y modernas conservadas en Andalucía. Documentación gráfica, análisis científico e interrelaciones

Flow-concurrence and bandwidth ratio on the Internet

The relevance of flow-based monitoring in tasks such as the detection of anomalies and denial of use attacks, traffic reporting, performance evaluation, software routing among others motivates the study of the Internet traffic in terms of flows. However, by the time a network manager or practitioner start any of these tasks, they face the challenge of planning probes’ capacities, which depends on the number of concurrent flows. Unfortunately, while the bandwidth of a network or link, both in operation and in future deployments, can be known, or at least estimated in advance, nothing is known about the load in terms of concurrent flows. We aimed at filling this gap by studying the concurrence of flows with respect to the bandwidth normalized by factors such as protocol shares, timeouts, applications, time and years among others. As a result, we provide the research community with several models, based on lognormal distributions, and parameter estimates in such a way that any player in the Internet arena can estimate the number of concurrent flows in their own infrastructure. Moreover, such results emerge from a diverse set of network traces so making the extrapolation of conclusions viableThis work was partially funded by the Spanish Ministry of Economyand Competitiveness through the research project TRAFICA(MINECO/FEDER TEC2015-69417-C2-1-R

Aspectos teóricos e implementación del método iterativo GMRES para la resolución de sistemas lineales

Treballs Finals de Grau de Matemàtiques, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2018, Director: ArturoVieiro Yanes[en] In this work we study different theoretical aspects of the GMRES algorithm (Generalized Minimal RESidual), including the use of Krylov subspaces, general results on convergence and the adapted version with restarted GMRES(m). GMRES is an iterative method that approximates the solution of a linear system $Ax = b$ by looking for the solution that minimizes the residue within the Krylov subspace. This method can be applied to general linear systems, because it does not require an specific structure of the matrix $A$ of the system. It is especially suitable for system of high dimension when it is not possible to solve it by direct methods and when the classical iterative methods like Jacobi, Gauss-Seidel or SOR do not converge or do not converge in a reasonable amount of time. We complement the work with several remarks and pseudo-code schemes useful for the implementation (in C language) that we have done of the method. We use our own implementation of GMRES in several examples, improving the implementation until we reach the final version (included in the Appendix). In the memory we present some examples to illustrate some aspects of the convergence of GMRES for different spectra of $A$

Characterizing the spatial and temporal diversity of the Internet Traffic: a capacity planning application to the RedIRIS network

Tesis doctoral inédita. Universidad Autónoma de Madrid, Escuela Politécnica Superior, marzo de 201

Respuesta ácido-base a esfuerzos máximos en futbolistas profesionales

La conservación del pH del organismo en un margen estrecho es, para los seres vivos, de una importancia trascendental. Se puede generalizar que en las reacciones químicas del metabolismo participan y se producen una gran cantidad de ácidos y, a pesar de ello, la concentración de iones hidrógeno libres en los diferentes compartimentos corporales permanece estable dentro de unos límites concretos. Esto se debe, en primer lugar, a la acción amortiguadora de los tampones fisiológicos o sistemas “buffer” que actúan inmediatamente en el medio interno neutralizando grandes modificaciones en la concentración de protones. En un segundo orden, se encuentra la acción reguladora de pulmón y riñón con mecanismos que son, en definitiva, los últimos encargados del mantenimiento del pH. Debido a esta capacidad de amortiguación, en el ejercicio físico, a lo largo de un amplio rango de intensidades de trabajo, el pH del medio interno se preserva muy cercano a las cifras basales en condiciones de reposo. A partir de una determinada intensidad, el pH desciende en relación inversa a la carga de trabajo entrando en rango de acidosis. Al final, con las altas intensidades deportivas y esfuerzos máximos, el pH llega a sus valores más ácidos, pudiéndose relacionar con la consecuente situación de fatiga en esas circunstancias. La disminución del pH sanguíneo fuera de los valores habituales durante un ejercicio es el efecto principal de la participación dominante del metabolismo anaeróbico, y se relaciona, entre otros, al aumento de las concentraciones de lactato en sangre observado con intensidades de esfuerzo creciente. Por otro lado, la presión parcial de dióxido de carbono desciende en el intento de atenuar la caída del pH. Esto se debe a la acción compensadora respiratoria que busca eliminar, con la hiperventilación, el CO2 generado en los mecanismos de tamponamiento plasmático con el consumo de bicarbonato, que también desciende en este proceso..

Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.V. López, J. L. García-Dorado, J. A. Hernández, and J. Aracil, "Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers", in ICTON Mediterranean Winter Conference, 2007. ICTON-MW 2007, p. 1-6Recent research in optical burst switched networks has proposed solutions to support subwavelength reservation for the periodic transmission of data bursts, which can coexist with conventional asynchronous bursts, bringing the polymorphous, agile and transparent optical networks (PATON) [1]. Thus, network operators can distribute IPTV channels to their customers, whereby they can use the spare bandwidth for the transmission of best-effort traffic, making use of the free gaps in between such periodic reservations. This work proposes scheduling algorithms for the transmission of periodic channels using PATON, and studies the blocking probability observed by best-effort traffic, when such scheduling algorithms are used.This work has been partially funded by the Spanish Ministry of Science and Education under the project DIOR (TEC2006-03246), and by the Comunidad Autónoma de Madrid under project e-Magerit (S-0505/TIC/000251). The authors would also like to acknowledge the support from the European Union VI Framework Programme e- Photon/ONe+ Network of Excellence (FP6-IST-027497)

La intermediación laboral en Andalucía: Análisis de los modelos de búsqueda de empleo

La descentralización de los Servicios Públicos de Empleo ha culmin ado su proceso en Andalucía en 2004 con las transferencias de competencias en materia de empleo y posterior puesta en marcha del Servicio Andaluz de Empleo (SAE). Para la Administración Regional supone un reto y la oportunidad de abordar la gestión de las políticas de empleo desde una perspectiva innovadora. En este contexto se ha realizado este estudio con el objetivo de analizar la funcionalidad de los distintos mecanismos de intermediación laboral existentes en Andalucía, con una metodología ecléctica que incluye en su análisis todas las dimensiones tangibles e intangibles, formales e informales, relacionadas con el proceso de búsqueda y acceso al empleo por parte de los ciudadanos en Andalucía. En esta comunicación se presentan la metodología aplicada así como los principales resultados obtenidos de la investigación realizada

PILEP: a contribution to PCE-based interdomain path computation

The process of computing routes that network traffic must follow throughout Internet has become more complex in the last years. Nowadays, this process is subject to the application of several constraints related to traffic engineering, resources management, quality of the offered services, security or robustness. The application of all these constraints has caused an increase of complexity of those nodes in charge of path computation. Sometimes, the amount of time and resources spent to compute routes is superior to resources used in the main task of these nodes: traffic classification and forwarding. PCE (Path Computation Element) architecture is being developed to diminish that problem in the context of constraint-based path computation for MPLS (Multiprotocol Label Switching). Although research work in relation to this topic is making progress quickly, there are still some unsolved aspects. As a contribution to PCE development, in this work we present a mechanism called PILEP (Procedure for Interdomain Location of External PCEs) that allows the dynamic discovery of routes computation elements in interdomain environments, making use of the existing routing protocols.Postprint (author’s final draft

DNS weighted footprints for web browsing analytics

The monetization of the large amount of data that ISPs have of their users is still in early stages. Specifically, the knowledge of the websites that specific users or aggregates of users visit opens new opportunities of business, after the convenient sanitization. However, the construction of accurate DNS-based web-user profiles on large networks is a challenge not only because the requirements that capturing traffic entails, but also given the use of DNS caches, the proliferation of botnets and the complexity of current websites (i.e., when a user visit a website a set of self-triggered DNS queries for banners, from both same company and third parties services, as well for some preloaded and prefetching contents are in place). In this way, we propose to count the intentional visits users make to websites by means of DNS weighted footprints. Such novel approach consists of considering that a website was actively visited if an empirical-estimated fraction of the DNS queries of both the own website and the set of self-triggered websites are found. This approach has been coded in a final system named DNSprints. After its parameterization (i.e., balancing the importance of a website in a footprint with respect to the total set of footprints), we have measured that our proposal is able to identify visits and their durations with false and true positives rates between 2 and 9% and over 90%, respectively, at throughputs between 800,000 and 1.4 million DNS packets per second in diverse scenarios, thus proving both its refinement and applicabilityThe authors would like to acknowledge funding received through TRAFICA (TEC2015-69417-C2-1-R) grant from the Spanish R&D programme. The authors thank Víctor Uceda for his collaboration in the early stages of this wor