Improved dynamical particle swarm optimization method for structural dynamics

A methodology to the multiobjective structural design of buildings based on an improved particle swarm optimization algorithm is presented, which has proved to be very efficient and robust in nonlinear problems and when the optimization objectives are in conflict. In particular, the behaviour of the particle swarm optimization (PSO) classical algorithm is improved by dynamically adding autoadaptive mechanisms that enhance the exploration/exploitation trade-off and diversity of the proposed algorithm, avoiding getting trapped in local minima. A novel integrated optimization system was developed, called DI-PSO, to solve this problem which is able to control and even improve the structural behaviour under seismic excitations. In order to demonstrate the effectiveness of the proposed approach, the methodology is tested against some benchmark problems. Then a 3-story-building model is optimized under different objective cases, concluding that the improved multiobjective optimization methodology using DI-PSO is more efficient as compared with those designs obtained using single optimization.Peer ReviewedPostprint (published version

Nuevas formas de religiosidad y reelaboraciones identitarias en migración: el caso de la comunidad murid en España

La desterritorialización de los movimientos religiosos provocada por la migración marca la dislocación del tejido social constitutivo de los mismos y, con ello, la transformación de ciertas prácticas y discursos religiosos. Este artículo propone una reflexión sobre las transformaciones de la práctica religiosa que implica la transnacionalización del hecho religioso a partir de un estudio de caso sobre la tariqa murid, una cofradía sufí de origen senegalés, en España. Se esboza un análisis de varios elementos de la religiosidad murid en relación con la práctica religiosa y los principios normativos que la sustentan y su reelaboración en el contexto migratorioThe deterritorialization of religious movements caused by migration involves the dislocation of the social fabric that constitutes them thus transforming religious practices and discourses. This paper proposes a reflection on the transformation of religious practices due to the transnationalization of religion movements through a case study of the Murid tariqa, a Sufi brotherhood of Senegalese origin, in Spain. The paper depicts an analysis of various elements of the Murid religiosity in relation to religious practices and the normative principles that underpin them in the migration contex

El eje Norte-Sur en los libros alemanes de viaje por España.

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Finite element analysis of the indentation test on rocks with microstructure

International audienceStrength parameters of rocks are currently determined from indentation tests. In this paper, a finite element analysis of this test is presented and scale effect is studied. The rock is modelled as an elasto-plastic medium with Cosserat microstructure and consequently possesses an internal length. The response of the indentation curve is studied for various values of the size of the indentor as compared to the internal length of the rock in order to assess the scale effect

The P-Adaptive BIEM Version in Elastostatics

This paper introduces the p-adaptive version of the boundary element method as a natural extension of the homonymous finite element approach. After a brief introduction to adaptive techniques through their finite element formulation in elastostatics, the concepts are cast into the boundary element environment. Thus, the p-adaptive version of boundary integral methods is shown to be a generalization of already well known ideas. In order to show the power of these numerical procedures, the results of two practical analysis using both methods are presented

A bi-cubic transformation for the numerical evaluation of the Cauchy principal value integrals in boundary methods

The numerical strategies employed in the evaluation of singular integrals existing in the Cauchy principal value (CPV) sense are, undoubtedly, one of the key aspects which remarkably affect the performance and accuracy of the boundary element method (BEM). Thus, a new procedure, based upon a bi-cubic co-ordinate transformation and oriented towards the numerical evaluation of both the CPV integrals and some others which contain different types of singularity is developed. Both the ideas and some details involved in the proposed formulae are presented, obtaining rather simple and-attractive expressions for the numerical quadrature which are also easily embodied into existing BEM codes. Some illustrative examples which assess the stability and accuracy of the new formulae are included

Remarks on methods for the computation of boundary-element integrals by co-ordinate transformation

It is well known that the evaluation of the influence matrices in the boundary-element method requires the computation of singular integrals. Quadrature formulae exist which are especially tailored to the specific nature of the singularity, i.e. log(*- x0)9 Ijx- JC0), etc. Clearly the nodes and weights of these formulae vary with the location Xo of the singular point. A drawback of this approach is that a given problem usually includes different types of singularities, and therefore a general-purpose code would have to include many alternative formulae to cater for all possible cases. Recently, several authors1"3 have suggested a type independent alternative technique based on the combination of standard Gaussian rules with non-linear co-ordinate transformations. The transformation approach is particularly appealing in connection with the p.adaptive version, where the location of the collocation points varies at each step of the refinement process. The purpose of this paper is to analyse the technique in eference 3. We show that this technique is asymptotically correct as the number of Gauss points increases. However, the method possesses a 'hidden' source of error that is analysed and can easily be removed