Dante: A Self-Adapting Peer-to-Peer System

In this paper we introduce DANTE, an unstructured P2P system in which the topology of the underlying overlay network can be dynamically adapted to the system conditions. Such an adaption is performed by the peers in an autonomous manner. DANTE uses a simple search mechanism based on random walks that, combined with the topology adaptation, allows it to work in a very efficient way. We have evaluated how DANTE behaves in practice, showing that it adapts very well to varying system conditions

Proyecto del sistema de gestión de riesgos laborales - Plan de emergencia y evacuación para el Instituto de Altos Estudios Nacionales. Escuela de Gobierno y Administración Pública

Considerando que: “El Instituto de Altos Estudios Nacionales, IAEN, es un centro de educación superior de postgrado, con personería jurídica, de derecho público, patrimonio propio y sin fines de lucro; forma parte del Sistema Nacional de Educación Superior Ecuatoriano, se rige por la Constitución Política de la República y la Ley Orgánica de Educación Superior y su Reglamento” Como estudiante he considerado importante presentar el proyecto de PLAN DE EMERGENCIA Y EVACUACIÓN PARA EL INSTITUTO DE ALTOS ESTUDIOS NACIONALES, QUITO-ECUADOR, con el concurso de sus docentes investigadores, instalaciones y equipos.1.Marco Teórico 2. Organización para emergencias IAEN 3. Plan de emergencia y evacuación IAEN 4. Conclusiones y recomendacione

On the selection of hidden neurons with heuristic search strategies for approximation

Feature Selection techniques usually follow some search strategy to select a suitable subset from a set of features. Most neural network growing algorithms perform a search with Forward Selection with the objective of finding a reasonably good subset of neurons. Using this link between both fields (feature selection and neuron selection), we propose and analyze different algorithms for the construction of neural networks based on heuristic search strategies coming from the feature selection field. The results of an experimental comparison to Forward Selection using both synthetic and real data show that a much better approximation can be achieved, though at the expense of a higher computational cost.Peer ReviewedPostprint (published version

Extended linear models with Gaussian prior on the parameters and adaptive expansion vectors

We present an approximate Bayesian method for regression and classification with models linear in the parameters. Similar to the Relevance Vector Machine (RVM), each parameter is associated with an expansion vector. Unlike the RVM, the number of expansion vectors is specified beforehand. We assume an overall Gaussian prior on the parameters and find, with a gradient based process, the expansion vectors that (locally) maximize the evidence. This approach has lower computational demands than the RVM, and has the advantage that the vectors do not necessarily belong to the training set. Therefore, in principle, better vectors can be found. Furthermore, other hyperparameters can be learned in the same smooth joint optimization. Experimental results show that the freedom of the expansion vectors to be located away from the training data causes overfitting problems. These problems are alleviated by including a hyperprior that penalizes expansion vectors located far away from the input data.Peer ReviewedPostprint (author's final draft

Design and Implementation of a Wireless Recorder System for Seismic Noise Array Measurements

In this work, a wireless data acquisition system for seismic noise array measurements is presented. The developed system is composed of a series of nodes and a central server arranged in a point-to-multipoint topology. The nodes consist of a CC3200 microcontroller, an analog-to-digital converter, and a low-noise conditioning circuit designed specifically to register seismic noise, and which is connected to the seismic sensor. As a server, a Raspberry Pi 4B has been used that will receive the samples from the nodes via Wi-Fi and will save them in files. It also incorporates a Web interface developed with JavaScript node.js technology that allows to configure the number of nodes as well as different options, to start and stop the records, and to view in real time the different signals received from the nodes. The system can be deployed anywhere since each of the nodes use independent batteries as a power supply. In addition, it is possible to operate the system remotely if internet connectivity is available. The prototype has been tested in four different locations in the Alicante province (southeast Spain), demonstrating its suitability for seismic noise array measurements

Design and Implementation of a Wireless Sensor Network for Seismic Monitoring of Buildings

This article presents a new wireless seismic sensor network system, especially design for building monitoring. The designed prototype allows remote control, and remote and real-time monitoring of the recorded signals by any internet browser. The system is formed by several Nodes (based on the CC3200 microcontroller of Texas Instruments), which are in charge of digitizing the ambient vibrations registered by three-component seismic sensors and transmitting them to a central server. This server records all the received signals, but also allows their real-time visualization in several remote client browsers thanks to the JavaScript’s Node.js technology. The data transmission uses not only Wi-Fi technology, but also the existing network resources that nowadays can be found usually in any official or residential building (lowering deployment costs). A data synchronization scheme was also implemented to correct the time differences between the Nodes, but also the long-term drifts found in the internal clock of the microcontrollers (improving the quality of records). The completed system is a low-cost, open-hardware and open-software design. The prototype was tested in a real building, recording ambient vibrations in several floors and observing the differences due to the building structure.This study was funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No 821046, the Ministerio de Economía, Industria y Competitividad through research project CGL2016-77688-R, by the Consellería de Participación, Transparencia, Cooperación y Calidad Democrática de la Generalitat Valenciana, and by Research Group VIGROB-116 (University of Alicante)

Comentarios sobre “Puntos de equilibrio asintóticamente estables en nuevos sistemas caóticos”

In the commented paper ten nonlinear chaotic systems are presented. Authors state that these systems do not exhibit Shilnikov chaos. Unfortunately, this assertion is not correctly proved because they use an erroneous theorem from the literature.En el trabajo comentado, los autores presentan diez sistemas autónomos no lineales caóticos, de los que afirman que no tienen caos en el sentido de Shilnikov. Desgraciadamente, esta afirmación carece de fundamento pues utilizan un teorema erróneo de la literatura.Ministerio de Educación y Ciencia (Spain), Plan Nacional I+D+I co-financed / FEDER MTM2014-56272-C2Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía (Spain) FQM-276, TIC-0130Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía (Spain) P12-FQM-165

Double-zero degeneracy and heteroclinic cycles in a perturbation of the Lorenz system

In this paper we consider a 3D three-parameter unfolding close to the normal form of the triple-zero bifurcation exhibited by the Lorenz system. First we study analytically the double-zero degeneracy (a double-zero eigenvalue with geometric multiplicity two) and two Hopf bifurcations. We focus on the more complex case in which the doublezero degeneracy organizes several codimension-one singularities, namely transcritical, pitchfork, Hopf and heteroclinic bifurcations. The analysis of the normal form of a Hopf-transcritical bifurcation allows to obtain the expressions for the corresponding bifurcation curves. A degenerate double-zero bifurcation is also considered. The theoretical information obtained is very helpful to start a numerical study of the 3D system. Thus, the presence of degenerate heteroclinic and homoclinic orbits, T-point heteroclinic loops and chaotic attractors is detected. We find numerical evidence that, at least, four curves of codimension-two global bifurcations are related to the triple-zero degeneracy in the system analyzed.We thank the reviewers for their careful reading of the manuscript and their very constructive remarks which have helped a lot to improve the presentation of the results. This work has been partially supported by the Ministerio de Economia y Competitividad, Spain (project MTM2017-87915-C2-1-P, co-financed with FEDER funds) , by the Ministerio de Ciencia, Innovacion y Universidades, Spain (project PGC2018-096265-B-I00, co-financed with FEDER funds) and by the Consejeria de Economia, Innovacion, Ciencia y Empleo de la Junta de Andalucia, Spain (FQM-276, TIC-0130, UHU-1260150 and P20_01160)

Pepsinogen C is a new prognostic marker in primary breast cancer

En esta publicación evaluamos el valor pronóstico del pepsinógeno C en pacientes con cáncer de mama. El pepsinógeno C es una enzima proteolítica involucrada en la digestión de proteínas en el estómago y que también se haya presente en la mama. Nuestro grupo había identificado niveles más elevados de esta proteína en tumores bien diferenciados y con receptores estrogénicos positivos. Debido a que esta propuesta está en marcado contraste con la mayoría de los estudios que evalúan la importancia pronóstica de las enzimas proteolíticas en el cáncer de mama, se nos pidió que examináramos la posible relación entre los niveles de pepsinógeno C y la recurrencia del tumor y las tasas de supervivencia de las pacientes en un grupo más amplio. Examinamos la expresión de pepsinógeno C mediante tinción con inmunoperoxidasa en una serie de 243 cortes de tejido de cáncer de mama, y un total de 113 carcinomas (46,5%) se tiñeron positivamente para esta proteinasa, con claras diferencias en la intensidad y porcentaje de células teñidas. Las muestras se cuantificaron mediante el sistema HSCORE, que considera tanto la intensidad como el porcentaje de células teñidas en cada intensidad. La evaluación del valor pronóstico del pepsinógeno C se realizó de forma retrospectiva con un periodo medio de seguimiento de 48,5 meses. En el análisis multivariante incluimos el pepsinógeno C y otros factores predictores convencionales. Los valores de pepsinógeno C fueron significativamente más altos en los tumores bien diferenciados (89,1) y moderadamente diferenciados (88,5) que en los tumores poco diferenciados (27,7) (p < 0,001). De manera similar, se encontraron diferencias significativas en el contenido de pepsinógeno C entre los tumores con receptor de estrógenos (RE) positivo y los tumores con RE negativo (85,9 frente a 41,2, respectivamente; P < 0,05). Además, los resultados indicaron que el bajo contenido de pepsinógeno C predijo una supervivencia libre de enfermedad y una supervivencia global más cortas (p < 0,0001). El análisis en función del estado ganglionar mostró que la expresión de pepsinógeno C fue el factor más importante para predecir tanto la supervivencia libre de enfermedad como la supervivencia global en pacientes con ganglios positivos (p < 0,0001 en ambos casos) y pacientes con ganglios negativos (p < 0,005 y p < 0,01, respectivamente). Los resultados de este estudio tienen una gran relevancia porque confirmamos y ampliamos nuestra observación previa de que la producción de pepsinógeno C en los carcinomas mamarios es un factor de buen pronóstico e independiente de otros factores predictores

Self-limited autoimmune disease related to transient donor B cell activation in mice neonatally injected with semi-allogeneic F1 cells

BALB/c mice injected at birth with 108 semi-allogeneic (C57BL/6 x BALB.IgHb)F1 spleen cells develop a lupus-like syndrome in which autoantibodles bear exclusively the donor allotype. We have analyzed the evolution of donor B cell chimerism and the autoimmune manifestations during the first year of life in these mice. Anti-DNA, -histone, and -cardiolipln IgG antibodies as well as circulating immune complexes appeared in the second week of life, reached the highest values around the sixth week, and then progressively dropped to normal values after the sixth month in most mice. The kinetics of the evolution of the autoimmune manifestations, as well as the kinetics of serum donor Ig allotype, were parallel to the kinetics of donor B cell chimerism, which was particularly prominent in the spleens in early weeks of life, and progressively decreased after remission of the autoimmune syndrome. Membrane-proliferative glomerulonephritls, which was followed as the more representative histological abnormality in this model, was particularly evident after 10 weeks of life, but disappeared by the end of the follow-up. Interestingly, when mice with a self-limited disease were re-injected with 108 F1 spleen cells i.v., a flare in the serologlcal manifestations was observed. In these re-injected mice a predominance of anti-DNA, lgG1 antibodies bearing exclusively the donor allotype was also observed, as in the early weeks of life. These results emphasize the central role of donor B cell chimerism in the development and in the self-limitation of the autoimmune disease in parental mice neonatally injected with F1 cells and Indicate that the capacity to react with F1 cells, to generate a renewed burst of symptoms, persists in these mice after the disappearance of autoimmune finding