Aerodynamic Optimization of High-Speed Trains Nose using a Genetic Algorithm and Artificial Neural Network

An aerodynamic optimization of the train aerodynamic characteristics in term of front wind action sensitivity is carried out in this paper. In particular, a genetic algorithm (GA) is used to perform a shape optimization study of a high-speed train nose. The nose is parametrically defined via Bézier Curves, including a wider range of geometries in the design space as possible optimal solutions. Using a GA, the main disadvantage to deal with is the large number of evaluations need before finding such optimal. Here it is proposed the use of metamodels to replace Navier-Stokes solver. Among all the posibilities, Rsponse Surface Models and Artificial Neural Networks (ANN) are considered. Best results of prediction and generalization are obtained with ANN and those are applied in GA code. The paper shows the feasibility of using GA in combination with ANN for this problem, and solutions achieved are included

Short-range stationary patterns and long-range disorder in an evolution equation for one-dimensional interfaces

A novel local evolution equation for one-dimensional interfaces is derived in the context of erosion by ion beam sputtering. We present numerical simulations of this equation which show interrupted coarsening in which an ordered cell pattern develops with constant wavelength and amplitude at intermediate distances, while the profile is disordered and rough at larger distances. Moreover, for a wide range of parameters the lateral extent of ordered domains ranges up to tens of cells. This behavior is new in the context of dynamics of surfaces or interfaces with morphological instabilities. We also provide analytical estimates for the stationary pattern wavelength and mean growth velocity

Controversia en la publicidad. Mensajes subliminales vs mensajes polémicos

En el presente trabajo se presenta el uso de lo subliminal en el ámbito de la publicidad, desde sus orígenes hasta mensajes utilizados actualmente que, siendo controvertidos por diversos motivos, son englobados por muchos como una práctica subliminal. Para ello, por un lado se han revisado y analizado numerosas investigaciones previas con el objetivo de determinar la efectividad de la publicidad subliminal a través de las respuestas que consigue en los receptores. Por otro lado, se ha puesto en duda que esos mensajes controvertidos más actuales sean verdaderamente de tipo subliminal, incluyendo la realización de una pequeña entrevista a fin de comprobar la reacción que provocan en los entrevistados. Una vez realizado el proceso de investigación y análisis, se concluye que la efectividad de la publicidad subliminal es hoy en día incierta, existiendo numerosas investigaciones que rechazan su potencial o lo limiten a ciertas condiciones, pero con otras que sí lo afirman. Además, se ha determinado que esos mensajes controvertidos no entran en la definición estricta que aporta la Ley General de Publicidad de “publicidad subliminal”.This paper studies subliminal advertising, from its inception to the current controversial messages that have been been labeled as such -unfairly, will be argued. Hence, on the one hand, an extensive literature review has been undergone for the sake of determining the available scholar knowledge on its effectiveness. On the other hand, it will be defended that said controversies should not be encompassed under the "subliminal" label, with the additional support of a customized, yet modest survey. Under the light of such research and analysis, it will be argued that the available literature leaves unanswered the question about the subliminal advertising effectiveness, with convincing tales and evidence supporting both sides of the debate. In addition, it has been determined that these controversial messages do not fall within the General Advertising Law's strict definition of "subliminal advertising".Departamento de Organización de Empresas y Comercialización e Investigación de MercadosGrado en Administración y Dirección de Empresa

Formation and maintenance of nitrogen-fixing cell patterns in filamentous cyanobacteria

Cyanobacteria forming one-dimensional filaments are paradigmaticmodel organisms of the transition between unicellular andmulticellular living forms. Under nitrogen-limiting conditions, infilaments of the genus Anabaena, some cells differentiate into heterocysts,which lose the possibility to divide but are able to fixenvironmental nitrogen for the colony. These heterocysts form aquasiregular pattern in the filament, representing a prototype ofpatterning and morphogenesis in prokaryotes. Recent years haveseen advances in the identification of the molecular mechanism regulatingthis pattern. We use these data to build a theory on heterocystpattern formation, for which both genetic regulation and theeffects of cell division and filament growth are key components. Thetheory is based on the interplay of three generic mechanisms: localautoactivation, early long-range inhibition, and late long-range inhibition.These mechanisms can be identified with the dynamics ofhetR, patS, and hetN expression. Our theory reproduces quantitativelythe experimental dynamics of pattern formation and maintenancefor wild type and mutants. We find that hetN alone is notenough to play the role as the late inhibitory mechanism: a secondmechanism, hypothetically the products of nitrogen fixation suppliedby heterocysts, must also play a role in late long-range inhibition.The preponderance of even intervals between heterocysts arisesnaturally as a result of the interplay between the timescales of geneticregulation and cell division.We also find that a purely stochasticinitiation of the pattern, without a two-stage process, is enoughto reproduce experimental observations.Funding from the Spanish Ministry of Economy and Competitiveness through Grant PHYSDEV (FIS2012-32349) and the Ramón y Cajal Program (to S.A.)

Non-linear ripple dynamics on amorphous surfaces patterned by ion-beam sputtering

Erosion by ion-beam sputtering (IBS) of amorphous targets at off-normal incidence frequently produces a (nanometric) rippled surface pattern, strongly resembling macroscopic ripples on aeolian sand dunes. Suitable generalization of continuum descriptions of the latter allows us to describe theoretically for the first time the main nonlinear features of ripple dynamics by IBS, namely, wavelength coarsening and non-uniform propagation velocity, that agree with similar results in experiments and discrete models. These properties are seen to be the anisotropic counterparts of in-plane ordering and (interrupted) pattern coarsening in IBS experiments on rotating substrates and at normal incidence.Comment: 5 pages, 3 figure

Education and sport: relationships, construction and mutual influence

Realizar un análisis y reflexión sobre las relaciones existentes entre educación y deporte, a priori puede parecer una tarea sencilla o fácil, bien porque vivimos en una sociedad en la que se pone de manifiesto el deporte en todas sus dimensiones: cultural, económica, política…; o bien porque el deporte está presente en multitud de actos de nuestra vida cotidiana: ocio, recreación, espectáculo…Pero mucho más lejos de la realidad, se presenta como una tarea ardua, difícil y complicada. Por ello, con este artículo pretendemos profundizar un poco más sobre dichos conceptos y sus relaciones, planteándonos una serie de interrogantes que en principio pueden pasar desapercibidos; pero para nosotros, como docentes de la Educación Física -área curricular que tiene como campo de conocimiento ambos constructos-, hace que replanteemos ciertos planteamientos didácticos. Estas inquietudes nos han llevado a revisar el marco teórico conceptual sobre las relaciones existentes entre educación y deporte; puesto que, sí comulgamos con la filosofía de que el deporte es un fenómeno que está presente en la sociedad, que hay que trabajarlo, enseñarlo y favorecerlo desde las instituciones educativas… La Educación Física es el área idónea para desarrollar este trabajo, favoreciendo así el hecho de considerar el deporte como una actividad fundamental en el desarrollo integral y formación académica de los alumnos durante su etapa escolar.The fact of carrying out an analysis, and a reflection about the relationships between education and sports could be considered as a simple or easy task; either because we live in a society, in which sport is exposed in every its dimensions: cultural, economic, political...; or given the fact that sport is presented in a large group of our lives’ actions: free time, recreation, performance... However, far from the reality, it is displayed as arduous, difficult and complex task. Therefore, this article expects to delve more into those concepts and their connections, considering a series of questions that at the beginning can be seen unnoticed; but for the authors, as teachers of Physical Education – curricular area which is the field of knowledge of both of them – , makes them reflect again certain didactic proposals. These concerns make the writers revise the conceptual theoretical framework about the relationships between education and sport; given that, if they agree on the philosophy that sport is a phenomenon presented in society, which has to be worked, taught and assist it from the educational institutions... Physical Education is the ideal area to develop this work, that way supporting the fact of considering sport as a fundamental activity in the integral development, and the academic education of students during their school years

A Highly Available Cluster of Web Servers with Increased Storage Capacity

Ponencias de las Decimoséptimas Jornadas de Paralelismo de la Universidad de Castilla-La Mancha celebradas el 18,19 y 20 de septiembre de 2006 en AlbaceteWeb servers scalability has been traditionally solved by improving software elements or increasing hardware resources of the server machine. Another approach has been the usage of distributed architectures. In such architectures, usually, file al- location strategy has been either full replication or full distribution. In previous works we have showed that partial replication offers a good balance between storage capacity and reliability. It offers much higher storage capacity while reliability may be kept at an equivalent level of that from fully replicated solutions. In this paper we present the architectural details of Web cluster solutions adapted to partial replication. We also show that partial replication does not imply a penalty in performance over classical fully replicated architectures. For evaluation purposes we have used a simulation model under the OMNeT++ framework and we use mean service time as a performance comparison metric.Publicad

Aerodynamic Optimization of a High-speed Train using Genetic Algorithms

Genetic algorithms (GA) have been used for the minimization of the aerodynamic drag of a train subject to front wind. The significant importance of the external aerodynamic drag on the total resistance a train experiments as the cruise speed is increased highlights the interest of this study. A complete description of the methodology required for this optimization method is introduced here, where the parameterization of the geometry to be optimized and the metamodel used to speed up the optimization process are detailed. A reduction of about a 25% of the initial aerodynamic drag is obtained in this study, what confirms GA as a proper method for this optimization problem. The evolution of the nose shape is consistent with the literature. The advantage of using metamodels is stressed thanks to the information of the whole design space extracted from it. The influence of each design variable on the objective function is analyzed by means of an ANOVA test

Surrogate-based optimization of the nose shape of a train subjected to crosswind

Optimización multi-objetivo frente a varias direcciones del viento incidente del testero de un tren de alta velocida