3,372 research outputs found
Bipartisanship Breakdown, Functional Networks, and Forensic Analysis in Spanish 2015 and 2016 National Elections
In this paper we present a social network and forensic analysis of the vote
counts of Spanish national elections that took place in December 2015 and their
sequel in June 2016. Vote counts are extracted at the level of municipalities,
yielding an unusually high resolution dataset with over 8000 samples. We
initially consider the phenomenon of Bipartisanship breakdown by analysing
spatial distributions of several Bipartisanship indices. We find that such
breakdown is more prominent close to cosmopolite and largely populated areas
and less important in rural areas where Bipartisanship still prevails, and its
evolution mildly consolidates in the 2016 round, with some evidence of
Bipartisanship reinforcement which we hypothesize to be due to psychological
mechanisms of risk aversion. On a third step we explore to which extent vote
data are faithful by applying forensic techniques to vote statistics. We first
explore the conformance of first digit distributions to Benford's law for each
of the main political parties. The results and interpretations are mixed and
vary across different levels of aggregation, finding a general good
quantitative agreement at the national scale for both municipalities and
precincts but finding systematic nonconformance at the level of individual
precincts. As a complementary metric, we further explore the co-occurring
statistics of voteshare and turnout, finding a mild tendency in the clusters of
the conservative party to smear out towards the area of high turnout and
voteshare, what has been previously interpreted as a possible sign of
incremental fraud. In every case results are qualitatively similar between 2015
and 2016 elections.Comment: 23 pages, 21 figures, accepted for publication in Complexit
A singularly perturbed convection–diffusion problem with a moving pulse
A singularly perturbed parabolic equation of convection–diffusion type is examined. Initially the solution approximates a concentrated source. This causes an interior layer to form within the domain for all future times. Using a suitable transformation, a layer adapted mesh is constructed to track the movement of the centre of the interior layer. A parameter-uniform numerical method is then defined, by combining the backward Euler method and a simple upwinded finite difference operator with this layer-adapted mesh. Numerical results are presented to illustrate the theoretical error bounds established
Evaluación de las integrales singulares del M.E.C. tridimensional mediante transformaciones no lineales
Se presenta en este trabajo una técnica para la evaluación de las integrales singulares que aparecen en el Método de los Elementos de Contorno en Elasticidad tridimensional, basada en la utilización de transformaciones de coordenadas no lineales, tales como las utilizadas en el caso bidimensional.Peer Reviewe
Evaluación de las integrales singulares del M.E.C. tridimensional mediante transformaciones no lineales
Se presenta en este trabajo una técnica para la evaluación de las integrales singulares que aparecen en el Método de los Elementos de Contorno en Elasticidad tridimensional, basada en la utilización de transformaciones de coordenadas no lineales, tales como las utilizadas en el caso bidimensional.Peer Reviewe
On the Absence of Continuous Symmetries for Noncommutative 3-Spheres
A large class of noncommutative spherical manifolds was obtained recently
from cohomology considerations. A one-parameter family of twisted 3-spheres was
discovered by Connes and Landi, and later generalized to a three-parameter
family by Connes and Dubois-Violette. The spheres of Connes and Landi were
shown to be homogeneous spaces for certain compact quantum groups. Here we
investigate whether or not this property can be extended to the noncommutative
three-spheres of Connes and Dubois-Violette. Upon restricting to quantum groups
which are continuous deformations of Spin(4) and SO(4) with standard
co-actions, our results suggest that this is not the case.Comment: 15 pages, no figure
Determinación de tensiones de contacto mediante el M.E.C. en problemas multicuerpo con simetrÃa axial
Se presenta en este trabajo la formulación e implementación de elementos de contorno, del problema de contacto multicuerpo entre materiales elásticos ortótropos en situaciones de pequeños desplazamientos y deformaciones con simetrÃa axial. Se incluye asimismo una breve descripción del programa de ordenador que [513] [514] incluye elementos isoparamétricos lineales y cuadráticos, impone de forma explÃcita las condiciones de contacto entre n sólidss, permite la consideración de diferentes coeficientes de rozamiento en distintas ecuaciones a resolver en cada uno de los pasos del proceso incremental de carga mediante la utilización de la técnica de subestructuración y condensación de las superficies de interés en procssos de punzonamiento y ajustes con apriete.Peer Reviewe
Formulación del M.E.C. en elasticidad tridimensional mediante macroelementos y colocación no nodal
Se presenta en este trabajo un nuevo enfoque del Método de los Elementos de Contorno en Elasticidad tridimensional basado en una aproximación global de la geometrÃa en el interior de macroelementos junto con una estrategia de colocación no nodal, que permite obviar el tema de los nodos esquina, elimina la necesidad de evaluación del término libre que ahora es fijo y de valor 0.5 Sij y simplifica el tratamiento de subregiones con las ventajas que ello supone desde el punto de vista computacional.Peer Reviewe
Sharing of hand kinematic synergies across subjects in daily living activities
The motor system is hypothesised to use kinematic synergies to simplify hand control. Recent studies suggest that there is a large set of synergies, sparse in degrees of freedom, shared across subjects, so that each subject performs each action with a sparse combination of synergies. Identifying how synergies are shared across subjects can help in prostheses design, in clinical decision-making or in rehabilitation. Subject-specific synergies of healthy subjects performing a wide number of representative daily living activities were obtained through principal component analysis. To make synergies comparable between subjects and tasks, the hand kinematics data were scaled using normative range of motion data. To obtain synergies sparse in degrees of freedom a rotation method that maximizes the sum of the variances of the squared loadings was applied. Resulting synergies were clustered and each cluster was characterized by a core synergy and different indexes (prevalence, relevance for function and within-cluster synergy similarity), substantiating the sparsity of synergies. The first two core synergies represent finger flexion and were present in all subjects. The remaining core synergies represent coordination of the thumb joints, thumb-index joints, palmar arching or fingers adduction, and were employed by subjects in different combinations, thus revealing different subject-specific strategies
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