Proposal for optically realizing quantum game

We present a proposal for optically implementing the quantum game of the two-player quantum prisoner's dilemma involving nonmaximally entangled states by using beam splitters, phase shifters, cross-Kerr medium, photon detector and the single-photon representation of quantum bits.Comment: 4 pages, 4 figure

Study of Alpha-Sigma Phase Transformation in Mechanically Alloyed Fe-Cr-Sn Alloys

The solubility of tin is significantly extended by mechanical alloying in near equiatomic Fe-Cr alloys. The influences of Sn concentration and of grain size on the kinetics of formation of the sigma-phase have been studied using different techniques. The sigma-phase formation is much faster for as-milled alloys than it is for conventional alloys. The sigma-phase formation rate decreases with the increase of Sn concentration in alloys with nanometer-sized grains as it does in coarse-grained alloys. The mechanisms which are responsible for the slowing-down of the alpha-sigma transformation are different in both kinds of alloys

Seeding Strategies for Multi-Objective Test Case Selection: An Application on Simulation-based Testing

The time it takes software systems to be tested is usually long. This is often caused by the time it takes the entire test suite to be executed. To optimize this, regression test selection approaches have allowed for improvements to the cost-effectiveness of verification and validation activities in the software industry. In this area, multi-objective algorithms have played a key role in selecting the appropriate subset of test cases from the entire test suite. In this paper, we propose a set of seeding strategies for the test case selection problem that generate the initial population of multi-objective algorithms.We integrated these seeding strategies with an NSGA-II algorithm for solving the test case selection problem in the context of simulation-based testing. We evaluated the strategies with six case studies and a total of 21 fitness combinations for each case study (i.e., a total of 126 problems). Our evaluation suggests that these strategies are indeed helpful for solving the multi-objective test case selection problem. In fact, two of the proposed seeding strategies outperformed the NSGA-II algorithm without seeding population with statistical significance for 92.8 and 96% of the problems

Trabalhar e empobrecer? A evolução dos trabalhadores pobres em Portugal

Mestrado em Economia e Políticas PúblicasNesta dissertação, procuramos analisar a evolução dos trabalhadores pobres em Portugal, realidade que tem vindo a ganhar relevância com as mutações no mercado de trabalho nos últimos anos, fragilizando os trabalhadores, e com a crescente consciencialização da sociedade para os problemas da desigualdade e da pobreza, que constituem graves constrangimentos ao desenvolvimento do país. Entendendo a pobreza no trabalho como um fenómeno particularmente injusto - dado que se reporta a cidadãos que, apesar de contribuírem com o seu trabalho para a sociedade, não têm condições de vida que lhes permitam escapar à pobreza - procuramos desenhar um perfil dos trabalhadores pobres em Portugal, descortinar as causas e principais fatores que levam a que o fenómeno se manifeste, bem como medidas políticas que possam combater a pobreza no trabalho, como componente da política mais geral de combate à pobreza e à exclusão social.In this dissertation, we aim to analyse the evolution of the working poor in Portugal, a reality that has been increasing its relevancy, with the changes in the labour market in the recent years, weakening the workers, and with the growing consciousness on society for the problems of inequality and poverty, that constitute serious constraints to the country's development. Considering the in-work poverty as a phenomenon particularly unfair - since it's reported to citizens that, despite contributing with their work to society, don't have the living conditions that allow them to escape poverty - we seek to draw a profile of the working poor in Portugal, find the causes and main factors that lead to the phenomenon, as well as political measures that can fight in-work poverty, as a component to the broader policy against poverty and social exclusion.info:eu-repo/semantics/publishedVersio

Effects of top-hat laser beam processing and scanning strategies in laser micro-structuring

The uniform energy distribution of top-hat laser beams is a very attractive property that can offer some advantages compared to Gaussian beams. Especially, the desired intensity distribution can be achieved at the laser spot through energy redistribution across the beam spatial profile and, thus, to minimize and even eliminate some inherent shortcomings in laser micro-processing. This paper reports an empirical study that investigates the effects of top-hat beam processing in micro-structuring and compares the results with those obtainable with a conventional Gaussian beam. In particular, a refractive field mapping beam shaper was used to obtain a top-hat profile and the effects of different scanning strategies, pulse energy settings, and accumulated fluence, i.e., hatch and pulse distances, were investigated. In general, the top-hat laser processing led to improvements in surface and structuring quality. Especially, the taper angle was reduced while the surface roughness and edge definition were also improved compared to structures produced with Gaussian beams. A further decrease of the taper angle was achieved by combining hatching with some outlining beam passes. The scanning strategies with only outlining beam passes led to very high ablation rates but in expense of structuring quality. Improvements in surface roughness were obtained with a wide range of pulse energies and pulse and hatch distances when top-hat laser processing was used

Proceso político y movimiento obrero en América Latina

Entre el triunfo de la Revolución Socialista Cubana, el ascenso al gobierno de la Unión Popular en Chile y el triunfo de la Revoluión Sandinista de Nicaragua, el fenómeno latinoamericano de mayor peso ha sido el de la crisis política en que tienen marco los movimientos de masas organizadas. Su consecuencia inmediata ha sido el agravamiento y mayor complejidad de los problemas del movimiento obrero en el Área. Ramón Martínez Escamilla, Marcos Kaplan, José María Calderón, Sergio Bagú, Julio Godio, Julio le Riverend e Irma Manrique ofrecen en Proceso político y movimiento obrero en América Latina un aporte fundamental a la reinterpretación que exige en nuestro tiempo tal estado de cosas

Quasiparticle excitations in relativistic quantum field theory

We analyze the particle-like excitations arising in relativistic field theories in states different than the vacuum. The basic properties characterizing the quasiparticle propagation are studied using two different complementary methods. First we introduce a frequency-based approach, wherein the quasiparticle properties are deduced from the spectral analysis of the two-point propagators. Second, we put forward a real-time approach, wherein the quantum state corresponding to the quasiparticle excitation is explicitly constructed, and the time-evolution is followed. Both methods lead to the same result: the energy and decay rate of the quasiparticles are determined by the real and imaginary parts of the retarded self-energy respectively. Both approaches are compared, on the one hand, with the standard field-theoretic analysis of particles in the vacuum and, on the other hand, with the mean-field-based techniques in general backgrounds.Comment: 53 pages, 4 figures. Version accepted for publication in Ann. Phy