531 research outputs found
(0, ½, 1) matrices which are extreme points of the generalized transitive tournament polytope
AbstractFollowing Brualdi and Hwang, given a generalized transitive tournament (GTT) matrix T of ordern, we consider the *-graph ofT, that is, the undirected graph with vertices 1, 2, …,n in which there is an edge {i,j} between verticesi andj if and only if0 < tij < 1. We characterize the *-graphs of the extreme GTT (0, ½, 1) matrices of order n. Using this characterization, we obtain for n = 6, 7 the complete list of extreme GTT (0, ½, 1) matrices of ordern
Dimensión de género en la ciudadanÃa: cambio familiar, cultura polÃtica y polÃticas de igualdad en España
El artÃculo sostiene que las familias españolas han cambiado poco porque muchas mujeres no son verdaderamente ciudadanas. El análisis se basa en un examen de la igualdad de la formulación de polÃticas de género, para analizar las intersecciones entre las estrategias familiares, el empoderamiento de las mujeres y el cambio familiar. Se adopta un acercamiento amplio al concepto de ciudadanÃa, para observar no sólo el conjunto de los derechos legales normalmente asociados al concepto, sino también el inventario de las prácticas sociales y rituales que permiten a las personas disfrutar de la plena incorporación en la comunidad polÃtica, asà como dotarlas de control total sobre su vida personal e Ãntima. La vida familiar y su organización, la ciudadanÃa y la igualdad de la formulación de polÃticas de género se entrecruzan de maneras múltiples y fundamentales: las polÃticas mal concebidas, y/o mal implementadas podrÃan dislocar a las mujeres, alejándolas de la ciudadanÃa plena; estos problemas, a su vez, pueden contribuir en gran medida a la consolidación de arreglos familiares tradicionales.This article argues that Spanish families have changed little because many women are less than full citizens. The analysis draws on an examination of gender equality policy-making, to discuss the often-neglected intersections between family strategies, women’s empowerment and family change. Citizenship is seen in an expansive way, to note not just the set of legal entitlements normally attached to the concept, but also the stock of social practices and rituals that allow individuals to enjoy full incorporation in their policies as well as full control of their personal and even intimate lives. Family life and organization, citizenship, and gender equality policy-making intersect in manifold and fundamental ways: badly conceived, and/or badly implemented policies could dislocate women to push them away from full citizenship; these, in turn, can contribute greatly to the consolidation of traditional family arrangements
Application of aircraft's flight testing techniques to the aerodynamic characterization of power kites
This thesis has developed an experimental methodology for the flight testing and data analysis of
power kites applied to Airborne Wind Energy Systems (AWES). In particular, the Estimation
Before Modeling technique, a well-known method in the aerospace industry for the aerodynamic
characterization of an aircraft using real flight data, has been adapted for tethered aircraft. The
developed methodology has two main building blocks: (i) an experimental setup to record
experimental data during the flight testing, and (ii) a Flight Path Reconstruction algorithm to
estimate the state of the system from the experimental data. From them, the aerodynamic
characteristics of two types of kites were investigated.
The proposed experimental setup was designed to be low cost, portable and easily adaptable to
both, rigid and semi-rigid kites. It is composed of an instrumented kite representative of the ones
used in AWES, an instrumented control bar, a ground computer and a wind station. Whenever it
was possible, commercial off the shelf components have been used, including low cost openhardware
sensors based on the PixHawk platform. However, after the first flight tests were
conducted and the obtained results were discussed, high precision sensors were also included.
The Flight Path Reconstruction (FPR) algorithm for tethered aircraft is based on an Extended Kalman
Filter (EKF). In addition to the standard set of estimated state variables (ie. Euler angles, position
or ground speed), the algorithm also provides the aerodynamic torque and forces upon the kite as
well as the tether tensions and wind velocity vector. The EBM technique, and the FPR algorithm
have been used to identify the aerodynamic characteristics of both, four-line Leading Edge
Inflatable (LEI) kites and two-line Rigid Frame Delta (RFD) kites. Quantitative and qualitative
results have been obtained. Albeit both types of kites exhibited very high AoA during the flight,
some significant differences were found. In particular, the estimated lift coefficient of the LEI
kite showed a behavior identified with a post-stall condition, while the RFD showed a pre-stall
behavior with a lower AoA and a positive relation between the lift coefficient and the kite AoA.
The presented experimental methodology can be of great interest for AWE industry as it helps to
improve modeling of tethered aircraft, leading to more accurate performance figures which may
increase investors interest in the technology. Moreover, flight testing methodologies and
experimental data analysis are of great interest for benchmarking AWES performances,
contributing to de-risk their development process and providing better tools for AWE "best
concept" identification. Finally, as a sub-product of the presented methodology, the FPR
algorithm can be used as a validated state estimator of the tethered aircraft, which is a key
element of a closed loop flight control system.Programa de Doctorado en Mecánica de Fluidos por la Universidad Carlos III de Madrid; la Universidad de Jaén; la Universidad de Zaragoza; la Universidad Nacional de Educación a Distancia; la Universidad Politécnica de Madrid y la Universidad Rovira i VirgiliPresidente: Marco Fontana.- Secretario: Manuel GarcÃa-Villalba Navaridas.- Vocal: Félix Terroba RamÃre
Post-Marriage LGBT Politics in Spain
Published in Reviews and Critical Commentary: http://councilforeuropeanstudies.org/critcom/post-marriage-lgbt-politics-in-spain/Council of European Studie
Three coefficients of a polynomial can determine its instability
AbstractWe will prove that, in some cases, if we know only three coefficients of a polynomial with positive coefficients and without any restriction on the magnitude of its degree, we can conclude that the polynomial is unstable. Namely, if P(x)=∑i=02naix2n−i is a polynomial with positive coefficients and for some q∈{1,…,n−1} it is satisfied that a2q<(nq)a0(n−q)/na2nq/n, then P(x) is unstable
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