Demand prediction of public bike sharing services using machine learning algorithms

Machine learning algorithms are used in the transportation field to successfully identify patterns and predict user?s behavior. This study aims to predict the demand of bike sharing services by means of this type of algorithms. The necessary input data and best parameters leading to optimal results will be identified, and a case study based in the bicing system in Barcelona, is going to be presented

Design and Modelling of a Non-linear Spring-mass Energy Harvesting Device for Wind Turbine Applications

This project addresses the development of a vibrational energy harvester for deployment at the blade-tips of large-scale wind turbines. In this work, a non-linear single-degree-of-freedom massspring system is chosen on the basis of an extensive literature review. An electromagnetic energy harvester based on a magnet moving between two springs (an approximate volume of 10x3.5x3.5 cm3 and natural frequency < 10 Hz) is tested experimentally for different distances between the two springs. Additionally, a model that aims to predict the harvester power output is developed. The model consists of a coupled electro-dynamic system to represent the dynamic and the electrical behaviour of the harvester, with the discretization of the coil to approximate the magnetic damping and the electromotive force generated. A finite element analysis carried with COMSOL Multiphysics, based on the remanent magnetic field density, is used to determine the magnetic field of the magnet in the centre of the coils. The results show that when the distance between the top and the bottom spring is increased from 16 mm to 18 mm, there is a shift of frequency that goes from 9 Hz to 8 Hz and an rms power generated of 1.53 mW and 1.27 mW, respectively, for a 0.2 g rms acceleration. For a 0.5 g rms acceleration the shift of frequency goes from 9.5 Hz to 8.5 Hz and the rms power generated was 2.28 mW and 1.59 mW respectively. The model is able to predict the power output and the frequency shift for distances between springs close to the one used to tune the model (+2 mm). Further development on the model will allow to use the MATLAB scripts to optimise the harvester and obtain its main characteristics for a given wind turbine blade and operational characteristics

Els parallamps radioactius

Abstract not availabl

Tota escola de nova creació, una escola mallorquina més

Abstract not availabl

Implementació de lones fotovoltaiques en les cobertes dels polígons CIM La Selva i CIM Vallès

Aquest projecte té com a objectiu fonamental l’estudi de l’aplicació de la tecnologia fotovoltaica de capa fina sobre les diferents cobertes de les plantes industrials del CIM La Selva i CIM Vallès en elements actius de captació i transformació de l’energia fotovoltaica per poder-la utilitzar principalment per l’autoconsum dels propis edificis i les seves activitats. El projecte es centra en els polígons del CIM La Selva i CIM Vallès les parcel·les dels quals s’han comptabilitzat per conèixer la superfície de les cobertes que podria servir per acollir les instal·lacions fotovoltaiques. Existeixen diversos tipus de tecnologies fotovoltaiques, però en aquest projecte es proposa la opció de capa fina degut a les restriccions de pes de les cobertes. S’han plantejat dos tipus d’instal·lacions (20 kW i 100 KW) per aprofitar al màxim les cobertes i maximitzar la producció d’energia fotovoltaica. Els resultats obtinguts a l’estudi energètic ens mostren que les cobertes dels CIM La Selva i CIM Vallès tenen una capacitat de producció d’energia elèctrica de 3,44 i 12,47 GWh anuals cobrint el 56,55% i 77,20% de la demanda elèctrica respectivament. Es proposa destinar una petita part d’aquesta electricitat a trenta estacions de recàrrega de vehicles elèctrics que es construirien a la zona per obtenir millors resultats a l’estudi econòmic i mediambiental. Els càlculs mediambientals estimen que gràcies a aquest projecte, s’evitarien les emissions atmosfèriques anuals de 1226,51 t de CO2, 2130,26 kg de SO2 i 1678,38 kg de NOx. A l’anàlisi econòmic s’obtenen retorns d’inversió elevats, degut principalment a l’eficiència i al preu dels mòduls solars. El marc legislatiu espanyol tampoc ajuda a obtenir uns millors resultats amb impostos que perjudiquen encara més les instal·lacions fotovoltaiques. Es conclou al final del projecte que tot i els avantatges d’una instal·lació de panells lleugers i les seves aplicacions, possiblement s’ha d’esperar una situació més favorable

Strict upper and lower boundswith adaptive remeshing in limit state analysis

By writing the limit state analysis as an optimisation problem, and after resorting to suitable discretisations of the stress and velocity field, we compute strict bounds of the load factor. The optimisation problem is posed as a Second Order Conic Program (SOCP), which can be solved very efficiently using specific algorithms for conic programming. Eventually, the optimum stress and velocity fields of the lower and upper bound problem are used to construct an error measure (elemental gap) employed in an adaptive remeshing strategy. This technique is combined with an additional adaptive nodal remeshing that is able to reproduce fan-type mesh patterns around points with discontinuous surface loads. We paticularise the resulting formulation for twodimensional problems in plane strain, with VonMises andMohr-Coulomb plasticity. We demonstrate the effetiveness of the method with a set of numerical examples extracted from the literature

Bounds and adaptivity for 3D limit analysis

In the present paper we compute upper and lower bounds for limit analysis in two and three dimensions. From the solution of the discretised upper and lower bound problems, and from the optimum displacement rate and stress fields, we compute an error estimate defined at the body elements and at their boundaries, which are applied in an adaptive remeshing strategy. In order to reduce the computational cost in 3D limit analysis, the tightness of the upper bound is relaxed and its computation avoided. Instead, the results of the lower bound are used to estimate elemental and edge errors. The theory has been implemented for Von Mises materials, and applied to two- and three-dimensions examples.Peer Reviewe

Frag’r’Us:Knowledge-based sampling of protein backbone conformations for de novo structure-based protein design

The remodeling of short fragment(s) of the protein backbone to accommodate new function(s), fine-tune binding specificities or change/create novel protein interactions is a common task in structure-based computational design. Alternative backbone conformations can be generated de novo or by redeploying existing fragments extracted from protein structures i.e. knowledge-based. We present Frag'r'Us, a web server designed to sample alternative protein backbone conformations in loop regions. The method relies on a database of super secondary structural motifs called smotifs. Thus, sampling of conformations reflects structurally feasible fragments compiled from existing protein structures. Availability and implementation Frag'r'Us has been implemented as web application and is available at http://www.bioinsilico.org/FRAGRUS