Improvements in meta-heuristic algorithms for minimum cost design of reinforced concrete rectangular sections under compression and biaxial bending

A numerical procedure is proposed in this paper for achieving the minimum cost design of reinforced concrete rectangular sections under compression and biaxial bending by using biologically-inspired meta-heuristic optimization algorithms. The problem formulation includes the costs of concrete, reinforcement and formwork, obtaining the detailed optimum design in which the section dimensions and the reinforcement correspond to values used in practice. The formulation has been simplified in order to reduce the computational cost while ensuring the rigor necessary to achieve safe designs. The numerical procedure includes the possibility of using high-strength concrete and several design constraints, such as mínimum reinforcement and limiting the neutral axis depth. Two numerical examples are presented, drawing comparisons between the results obtained by ACI318 and EC2 standards

Pinceladas

Quiero expresar mi agradecimiento a los responsables de la Revista Universidad, Ética y Derechos, RUED@ - puesta en marcha por la Conferencia Española de Defensores Universitarios (CEDU) en 2015 - por la distinción que supone colaborar en la publicación de un colectivo universitario tan respetable y distinguido como es el de los Defensores que forman la CEDU. Gracias, en particular, a los Defensores Universitarios Eugenio Baraja Rodríguez y María Acale Sánchez por la generosidad que siempre he recibido de ellos. Tal compromiso de colaboración es para mí un honor y un privilegio

Imitación, oposición e innovación de las formas sociales: Finitud e infinitud en Las Leyes Sociales de Gabriel Tarde

En este texto presento una selección de fragmentos del libro "Las leyes sociales" de Gabriel Tarde (1843-1904), publicado originalmente en 1898, y traducido en castellano a principios del siglo XX. Después de un largo olvido Tarde ha sido revigorizado para el panteón de las ciencias sociales, llegando a ser convertido en un autor muy relevante para la teoría del actor-red (incluso siendo mencionado por Bruno Latour como su antepasado). Pero creo discusiones más interesantes que las de una nueva mítica de las figuras ancestrales. En esta introducción abogo más bien por una aproximación directa a la propia obra de Tarde, lo que nos permitiría ir más allá de cualquier uso presentista de una figura histórica para apuntalar una teoría precocinada para el consumo de masas. Es por esto que propongo nos centremos críticamente en los propios argumentos de Tarde, que describe "las leyes" de la vida social, hecha de formas potencialmente infinitesimales que se repiten y se diferencian (a lo que él se refiere como procesos de imitación, oposición e innovación). Y mencionaré a tal efecto algunas consideraciones críticas contemporáneas que ha recibido esta formulación en términos de leyes o su tratamiento sobre la escala de lo social, haciendo especial hincapié en la relación que establece entre la finitud y la infinitud de las formas socialesIn this text I present a selection of fragments of the book 'The social laws' by Gabriel Tarde (1843- 1904), published originally in 1898 and translated into Spanish at the beginning of the 20th century. After a long time condemned to oblivion Gabriel Tarde has been reinvigorated in recent decades for the pantheon of social sciences, even reaching the point of becoming a very relevant author for Actor-Network Theory (no less than Bruno Latour has turned him into 'ANT's ancestor'). However, I believe that the recuperation of Tarde's works could lead us to far more interesting discussions than a new mythic of ancestral figures. In this introduction I press for a more direct approach to Tarde's writings, something which might allow us to go beyond any presentist use of a historical figure to prop up a ready-made theory for mass-consumption. For this reason, I would like to propose to focus on Tarde's very own descriptions of the 'laws' of social life, made out of -potentially infinitesimal- social forms which repeat and differentiate -something he refers as the processes of imitation, opposition and innovation-. In that vein, I would like to mention some contemporary critical appraisals of those formulations in terms of 'laws' or Tarde's treatments of the scale of the social -where special attention is put on the relation he establishe

Creación de Digital Twins para las estaciones 1 y 2 de la línea de ensamblaje automático FMS-200

La Industria 4.0 está siendo considerada como el cambio más moderno del paradigma industrial gracias a la introducción del Internet de las Cosas. El sector secundario actualmente invierte cuantiosas cantidades de tiempo y dinero en tratar de introducir estas nuevas tecnologías en sus procesos, una de estas tecnologías son los llamados Digital Twin o Gemelo Digital. Esta memoria describe la confección paso a paso de un Digital Twin para una cadena de montaje modular y completamente automatizada llamada FMS-200. La construcción es descrita para el software de Siemens NX, y cada paso va acompañado de los problemas y soluciones necesarios para su creación. Posteriormente se muestra el proceso necesario para unirlo a otro Gemelo dedicado a otra parte de la misma máquina y su simulación simultánea, esto se logra haciendo uso de las herramientas proporcionadas por el software de TIA Portal.ndustry 4.0 is becoming well stablished as a completely new change of the industrial paradigm thanks to the introduction of the Internet of Things. Industries invest large amounts of time and money in the shake of introducing these new technologies within their processes, one of them is called Digital Twin. This thesis guides step by step through the creation of a Digital Twin for a completely automatic modular assembly line called FMS-200. The steps are explained for the Siemens NX software accompanied with every problem and solution that came up during the construction. After that, the thesis describes the process required to link the newly created Digital Twin with another one intended for a different part of the same machine and how to simulate with them simultaneously, this is achieved by making use of the tools provided by the TIA Portal software.Departamento de Ingeniería de Sistemas y AutomáticaGrado en Ingeniería en Tecnologías Industriale

Assessment of the use of preliminary concepts test and rubrics in practical learning at university

Comunicació presentada al ICERI 2019 12th annual International Conference of Education, Research and Innovation (Seville, Spain. 11-13 November, 2019).The high number of students and teachers in the laboratory practices of the course Theory of Machines and Mechanisms, shared by several engineering degrees at Universitat Jaume I, makes the teaching planning and evaluation challenging. Some issues were observed in past years, such as differences in the student knowledge of basic concepts, underpreparation before practical classes, poor quality of the written reports, absence of common objective assessment criteria among teachers and low success rate. That led us to the implementation of an action for educational improvement during the academic year 2018-2019. The aim was to improve the students' level of training before attending laboratory practices, to standardize the evaluation among teachers and to involve students in the process of assessment in order to improve learning outcomes and the quality of the reports delivered. The improvement action included, on one side, carrying out an initial evaluation with a diagnostic test. The results of this test were used to estimate the basic knowledge of the students and proposing specific tutorial sessions in order to unify their level of knowledge. This method should increase the students involvement and improve the success while performing the laboratory practices. On the other side, rubrics were created in order to standardize the correction criteria. These rubrics were also made public to the students, before the classes, in an attempt to improve the quality of their reports. In addition, for some of the reports the students were asked to self-assess their own reports following the public rubric. The results indicate that teachers found the rubrics useful for objective and fair evaluation. However, the standard deviation across teachers has not been apparently reduced with respect to the previous year by the use of them, although the differences in the student cohort have to be taken into account. The effect on grades of the factors teacher and session, as well as their interaction, was significant (p<.05) according to the ANOVA tests, as already was prior to the application of the action. It was also found that the student grades in the practical classes did not improved significantly. A low implication in the preparation before classes and a low tutorial attendance were observed in the collective of students, possible explaining in part the discrete improvements obtained. The self-assessment improved the grades on average where it was applied. We concluded that the involvement of both students and teachers is necessary to promote learning quality using these techniques

Pensar infraestructuralmente

Ensayo celebratorio de la publicación del libro de Mongili, A. y Pellegrino, G., eds., 2014. Information Infrastructure(s): Boundaries, Ecologies, Multiplicity. Cambridge: Cambridge Scholars

Clave taxonómica de la pteridoflora de las Islas Canarias

Se han confeccionado claves taxonómicas para la determinación de los diferentes taxones de helechos que han citado para las Islas Canarias. También se incluyen algunas ilustraciones que representan aspectos morfológicos que se han tenido en cuenta en el tSánchez Velázquez, T. 2004. Taxonomic key of the pteridophytes from the Canary Islands. Bot. Complut. 28: 39-50. In this paper taxonomic keys are presented for the identification of the different fern taxa reported for the Canary Islands. Some illustrations are included to show morphological characteristics used in this work

Development and Implementation of an Adaptive-Sweep Algorithm for Carrier Acquisition and Tracking in Spacecraft Radios

Les ràdios de les naus espacials transmeten un senyal modulat a una freqüència portadora, que posteriorment es demodula i es processa a banda base. Tanmateix, aquesta freqüència portadora canvia amb el temps a causa de l’efecte Doppler, que s’ha d’eliminar abans de la demodulació mitjançant l’adquisició i el seguiment de la portadora. Un algorisme per fer-ho ja està implementat a les ràdios de naus espacials desenvolupades per la NASA. Tot i això, utilitza un algorisme d’escombratge de pas fix per adquirir la portadora, una limitació que facilita la seva implementació en el maquinari de vol, però fa que el procés d’adquisició sigui fràgil. En aquesta tesi es presenta un nou algorisme d’adquisició de portadores que utilitza un pas adaptatiu, i el seu rendiment es quantifica en presència de soroll blanc. A més, també es presenta una implementació en programari que utilitza GNU Radio, i es comprova mitjançant simulacions amb una àmplia varietat de ratios de senyal a soroll. Finalment, els resultats presentats en aquest treball demostren la capacitat de l’algorisme d’adquirir i fer un seguiment de la portadora del Lunar Reconnaissance Orbiter.Las radios de las naves espaciales transmiten una señal modulada a una frecuencia portadora, que posteriormente se demodula y se procesa en banda base. Sin embargo, esta frecuencia portadora cambia con el tiempo debido al efecto Doppler, que debe eliminarse antes de la demodulación mediante la adquisición y el seguimiento de la portadora. Un algoritmo para hacerlo ya está implementado en las radios de naves espaciales desarrolladas por la NASA. Sin embargo, utiliza un algoritmo de barrido de paso fijo para adquirir la portadora, una limitación que facilita su implementación en el hardware de vuelo, pero hace que el proceso de adquisición sea frágil. En esta tesis se presenta un nuevo algoritmo de adquisición de portadoras que utiliza un paso adaptativo, y su rendimiento se cuantifica en presencia de ruido blanco. Además, también se presenta una implementación en software que utiliza GNU Radio, y se comprueba mediante simulaciones con una amplia variedad de ratios de señal a ruido. Finalmente, los resultados presentados en este trabajo demuestran la capacidad del algoritmo de adquirir y hacer un seguimiento de la portadora del Lunar Reconnaissance Orbiter.Spacecraft radios transmit a signal modulated at a carrier frequency, which is later demodulated and processed at baseband. However, this carrier frequency shifts over time due to the Doppler effect, which must be removed prior to demodulation by acquiring and tracking the carrier. An algorithm to do so is already implemented in spacecraft radios developed by NASA. However, it uses a fixed-step sweep algorithm to acquire the carrier, a limitation that facilitates implementing it in flight hardware, but makes the acquisition process brittle. In this thesis, a novel carrier acquisition algorithm that uses an adaptive-step is presented and its performance is quantified in the presence of Additive White Gaussian Noise. Additionally, a software implementation using GNU Radio is also presented and tested in simulation for a wide variety of Signal to Noise Ratio conditions. Finally, results presented in this work demonstrate the ability of the algorithm to acquire and track the carrier of the Lunar Reconnaissance Orbiter.Outgoin

Perfomance analysis of hybrid systems based on externally heayed closed-cycle engines

This work presents a comparative analysis of hybrid systems that make use of closed-cycle externally heated bottoming systems. Two options are considered: reciprocating (Stirling) engines and supercritical carbon dioxide turbines. These engines share the common feature of working on closed cycles with optimised fluids (H2 and CO2 respectively). However, they differ in their internal structure: Stirling engines make use of volumetric machinery whereas the SCO2 system is composed by turbomachinery. In both cases, the working fluid is subjected to very high pressure and temperature in the range of 50-200 bar and 40-650 ºC. A brief description of both bottoming systems is provided in the article along with the expected performance of each case in on-design and off-design (part load) conditions. The analysis is therefore split into two stages. First, a comparison is shown for on-design operation aiming to evaluate the maximum efficiency attainable by the proposed systems. Second, a preliminary analysis of off-design operation is presented. The paper concludes that hybrid systems based on atmospheric fuel cells and externally heated closed-cycle bottoming engines have the potential to outperform conventional pressurised fuel cells and gas turbines hybrids while preserving the topping system from the demanding operating conditions of the latter configuratio