5,207 research outputs found
Estables y precarios : desregulación laboral y estratificación social en España
No full textJavier G. Polavieja.
ill. ; 22 cm.
Translation of: Insiders and outsiders : structure and consciousness effects of labour market deregulation in Spain, 1984-1997.
Thesis (doctoral) -- University of Oxford, 2001
High-speed FBG interrogator based on fiber interferometry and FPGA real-time processing
No full textRevista con referatoFil: Codnia, Jorge. Universidad Nacional de General Sarmiento. Instituto de Ciencias; Argentina.Fil: Codnia, Jorge. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Departamento de Investigaciones en Láseres y sus aplicaciones; Argentina.Fil: Elaskar, Javier. Scuola Superiore Sant’Anna. Institute of Mechanical Intelligence; ItalyFil: Luda, Marcelo A. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Departamento de Investigaciones en Láseres y sus aplicaciones; Argentina.Presentamos un interrogador de red de Bragg de fibra óptica de alta velocidad basado en un interferómetro activo de Sagnac y demodulación de portadora generada por fase, realizada en tiempo real mediante un sistema FPGA de bajo coste. El sistema cuenta con un ancho de banda de detección de 280 kHz y una frecuencia de muestreo de 1 MS/s, e implementa un esquema de mezcla multitono para reducir la distorsión.We present a high-speed fiber Bragg grating interrogator based on an active Sagnac interferometer and phase-generated-carrier demodulation performed in real time by a low-cost FPGA system. The system has 280kHz detection bandwidth and 1MS/s sampling rate, and implements a multitone-mixing scheme to reduce distortion.Apresentamos um interrogador de rede de Bragg de fibra óptica de alta velocidade baseado em um interferômetro Sagnac ativo e demodulação de portadora gerada por fase realizada em tempo real por um sistema FPGA de baixo custo. O sistema possui largura de banda de detecção de 280 kHz e taxa de amostragem de 1 ms/s, além de implementar um esquema de mistura multitonal para reduzir a distorção
Type-I intermittency with discontinuous reinjection probability density in a truncation model of the derivative nonlinear Schrödinger equation
No full textIn previous papers, the type-I intermittent phenomenon with continuous reinjection probability density (RPD) has been extensively studied. However, in this paper type-I intermittency considering discontinuous RPD function in one-dimensional maps is analyzed. To carry out the present study the analytic approximation presented by del Río and Elaskar (Int. J. Bifurc. Chaos 20:1185-1191, 2010) and Elaskar et al. (Physica A. 390:2759-2768, 2011) is extended to consider discontinuous RPD functions. The results of this analysis show that the characteristic relation only depends on the position of the lower bound of reinjection (LBR), therefore for the LBR below the tangent point the relation {Mathematical expression}, where {Mathematical expression} is the control parameter, remains robust regardless the form of the RPD, although the average of the laminar phases {Mathematical expression} can change. Finally, the study of discontinuous RPD for type-I intermittency which occurs in a three-wave truncation model for the derivative nonlinear Schrodinger equation is presented. In all tests the theoretical results properly verify the numerical dat
Interferometer-based chemical sensor on chip with enhanced responsivity and low-cost interrogation
No full textWe report experimental results of an interferometric chemical sensor integrated on a silicon chip. The sensor measures refractive index variations of the liquid that contacts exposed spiraled silicon waveguides on one branch of a Mach-Zehnder interferometer. The system requires neither laser tuning nor spectral analysis, but a laser at a fixed wavelength, and a demodulation architecture that includes an internal phase modulator and a real-time processing algorithm based on multitone mixing. Two devices are compared in terms of sensitivity and noise, one at 1550\&\#x2005;nm wavelength and TE polarization, and an optimized device at 1310\&\#x2005;nm and TM polarization, which shows 3 times higher sensitivity and a limit of detection of 2.24\&\#x00B7;10\&\#x2212;7 RIU
Noise effect on statistical properties of type-I intermittency
No full textIn this work we analyze the noise effect on type-I intermittency, for which we develop a methodology based on a recently proposed technique used to model the reinjection probability density (RPD). This new methodology allows us to study the noise effect on the intermittency statistical properties for relatively large noise strengths in a quadratic map with different reinjection mechanisms. We show that this procedure allows to predict the behavior of the noisy and noiseless system using the results of the M(x) function which is implemented to obtain the RPD function. We also derive an analytical approximation for the probability density of the laminar lengths and we obtain results for the average laminar length. All analytical approaches show a good agreement with the numerical results even though the statistical properties are calculated using either the noisy or noiseless data, however in some cases the description of the noiseless system using the noisy data can be inaccurate. In addition, we show that occasionally the presence of noise could be not detected due to the results behave as they would be corresponding to a noiseless system. This aspect may have important consequences especially when working with experimental data.Fil: Krause, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Elaskar, Sergio Amado. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: del Rio, Ezequiel. Universidad Politécnica de Madrid; Españ
Chaos and Intermittency in the DNLS Equation Describing the Parallel Alfvén Wave Propagation
No full textWhen the Hall effect is included in the magnetohydrodynamics equations (Hall-MHD model) the wave propagation modes become coupled, but for propagation parallel to the ambient magnetic field the Alfvén mode decouples from the magnetosonic ones, resulting in circularly polarized waves that are described by the derivative nonlinear Schrödinger (DNLS) equation. In this paper, the DNLS equation is numerically solved using spectral methods for the spatial derivatives and a fourth order Runge-Kutta scheme for time integration. Firstly, the nondiffusive DNLS equation is considered to test the validity of the method by verifying the analytical condition of modulational stability. Later, diffusive and excitatory effects are incorporated to compare the numerical results with those obtained by a three-wave truncation model. The results show that different types of attractors can exist depending on the diffusion level: for relatively large damping, there are fixed points for which the truncation model is a good approximation; for low damping, chaotic solutions appear and the three-wave truncation model fails due to the emergence of new nonnegligible modes.Fil: Krause, Gustavo Javier. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Elaskar, Sergio Amado. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Costa, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentin
Effect of the lower boundary of reinjection and noise in Type-II intermittency
No full textWe implement a recent methodology to study type-II intermittency considering different values of the lower boundary of reinjection (LBR) and the noise intensity. With this approach, analytical expressions for the reinjection probability density (RPD) are accurately obtained. The proposed RPD has a piecewise definition addressing the different reinjection mechanisms appearing in the system depending on the LBR value and the noise intensity. Also, the new probability density of the laminar lengths is calculated. When LBR = 0, the noisy probability density of the laminar lengths presents a cutoff, which disappears for noise strength different to zero. The theoretical results are verified with numerical simulations.Fil: Elaskar, Sergio Amado. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: del Rio, Ezequiel. Universidad Politécnica de Madrid; EspañaFil: Krause, Gustavo Javier. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Costa, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentin
The construction of opinion in Javier Marías: rhetorical-argumentative analysis of the columns published by the author between 2009 and 2013
No full textEl presente artículo tiene como objeto de estudio las columnas escritas por Javier Marías, entre los años 2009 y 2013, en el espacio semanal La Zona Fantasma, ubicado en la última página de El País Semanal, suplemento dominical del diario El País. Para el estudio se ha recurrido a un análisis de contenido, a partir de la retórica aristotélica y su posterior renovación por Charles Perelman y Lucie Olbrechts Tyteca, expuesta en su Tratado de la argumentación. La metodología seguida ha permitido identificar las particularidades y características en cuanto a temas, enfoque, estructura y lenguaje que el autor utiliza. Cuantitativamente, se identificaron los temas, los argumentos, el léxico y las figuras literarias de cada columna, y cualitativamente, las temáticas, la construcción del Ethos del autor y la interpretación de los resultados, a la luz del contexto que
enmarca los años en los que se escriben las columnasThis article has as object of study the columns written by Javier Marías between the years 2009 and 2013 in the weekly space “La Zona Fantasma”, located in the last page of El País Semanal, a Sunday supplement in the News Paper El País. For study purposes we have used an analysis of content based on the Aristotelian Rhetoric and its posterior renovation by Charles Perelman and Lucie Olbrechts-Tyteca, exposed in their Treaty of Argumentation. The methodology followed allowed to identify the particularities and characteristics in relation to topics, approach, structure and language the author uses. The qualitative contribution consisted of the conclusions about the data obtained.
This analysis focuses on the reflection around the topics, the construction of the author´s Ethos and the interpretation of the results due to the context that frames eventually, the years the column is writte
Homenaje de la Sociedad de Neurología del País Vasco a Javier Urkola Etxeberria
No full textThis article talks about the lecture given in the Annual Meeting of the Basque Country Neurology Society, dedicated to Doctor Javier Urkola Etxeberria. The author explains the professional career and private life of Doctor Urkola, from his beginnings as a teenager who was in contact with Neurology and Psychiatry, until his retirement from Public Health in the year 2000.En el siguiente artículo se resume la ponencia presentada en el marco de la Reunión Anual de la Sociedad de Neurología del País Vasco, donde se rindió homenaje al doctor Javier Urkola Etxeberria. El autor se encarga de trazar una semblanza de la trayectoria profesional y humana del doctor Urkola, uno de los pioneros de la especialidad en el País Vasco, desde sus primeros contactos con la Neurología y la Psiquiatría en su adolescencia, hasta su jubilación en la Sanidad Pública el año 2000.Euskal Herriko Neurologiako Elkarteak urtero ospatzen duen bileran, Javier Urkola Etxeberria neurologoari omenaldi bat egin zitzaion. Artikulu honetan, bertan egindako aurkezpenaren laburpen bat jasotzen da. Egileak Euskal Herriko Neurologia eta Psikiatriaren aitzindari izandako Urkolaren iharduera profesionala eta bizitza pertsonala deskribatzen du: bere nerabezaroan Neurologia zein Psikiatria arloetan izandako lehen harremanetik, 2000 urtean Osakidetzatik erretiratu zen arte
Labour Market Dualisation and Trade Union Involvement in Spain
No full textThis chapter analyses the process of labour market dualisation and its consequences for the relation between workers and trade unions in Spain. It examines the effects of the progressive fragmentation of the Spanish work force - i.e. the growing differentiation of a core of workers with stable jobs and a periphery without - on workers’ patterns of collective action, as well as on their attitudes to, and perceptions and evaluation of, trade unions. The chapter argues that the differentiation of unemployment risks by type of contract has produced a two-tier system of employment relations, in which the interests of fixed-term and unemployed workers are largely disregarded. It is important to approach the study of labour market dualisation from a dynamic perspective that stresses the longitudinal character of the phenomena of employment stability and instability. From an employment perspective, two-tier flexibilisation implies that fixed-term contracts, given their low costs, become the main channel of entry into employment.Peer reviewe
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