8,476 research outputs found
Conditional entropy of glueball states
The conditional entropy of glueball states is calculated using a holographic
description. Glueball states are represented by a supergravity dual picture,
consisting of a 5-dimensional graviton-dilaton action of a dynamical
holographic AdS/QCD model. The conditional entropy is studied as a function of
the glueball spin and of the mass, providing information about the stability of
the glueball states.Comment: 6 pages, 4 figure
O direito na perspectiva dos autores da sociologia clássica: Durkheim, Weber e Marx
Trata do Direito na perspectiva dos principais autores da Sociologia clássica. Analisa, de acordo com a visão de Durkheim, as influências da sociedade sobre o Direito e sua formação, a solidariedade social, os fatos sociais como o objeto da sociologia e suas características. Discorre, conforme a concepção de Weber, o individualismo metodológico e os tipos de dominação na História. Expõe, conforme Marx, o Estado e o Direito como intermediários e o Direito como ideologia a serviço da exploração capitalista
Mirax: A Brazilian X-Ray Astronomy Satellite Mission
We describe the ``Monitor e Imageador de Raios-X'' (MIRAX), an X-ray
astronomy satellite mission proposed by the high energy astrophysics group at
the National Institute for Space Research (INPE) in Brazil to the Brazilian
Space Agency. MIRAX is an international collaboration that includes, besides
INPE, the University of California San Diego, the University of Tuebingen in
Germany, the Massachusetts Institute of Technology and the Space Research
Organization Netherlands. The payload of MIRAX will consist in two identical
hard X-ray cameras (10 -200 keV) and one soft X-ray camera (2-28 keV), both
with angular resolution of ~ 5-6 arcmin. The basic objective of MIRAX is to
carry out continuous broadband imaging spectroscopy observations of a large
source sample (~ 9 months/yr) in the central Galactic plane region. This will
allow the detection, localization, possible identification, and
spectral/temporal study of the entire history of transient phenomena to be
carried out in one single mission. MIRAX will have sensitivities of ~ 5
mCrab/day in the 2-10 keV band (~2 times better than the All Sky Monitor on
Rossi X-ray Timing Explorer) and 2.6 mCrab/day in the 10-100 keV band (~40
times better than the Earth Occultation technique of the Burst and Transient
Source Experiment on the Compton Gamma-Ray Observatory). The MIRAX spacecraft
will weigh about 200 kg and is expected to be launched in a low-altitude (~ 600
km) circular equatorial orbit around 2007/2008.Comment: 6 pages, 1 table, 3 figures, presented at 2002 COSPAR meeting in
Houston. Submitted to Adv. Space Re
Superspace Formulation for the BRST Quantization of the Chiral Schwinger Model
It has recently been shown that the Field Antifield quantization of anomalous
irreducible gauge theories with closed algebra can be represented in a BRST
superspace where the quantum action at one loop order, including the Wess
Zumino term, and the anomalies show up as components of the same superfield. We
show here how the Chiral Schwinger model can be represented in this
formulation.Comment: 11 pages, Late
Digital transformation in recruitment : best practices in the Portuguese market
The “war for talent” is leading organizations to focus on recruitment process agility and employer branding as a way to successfully recruit the best individuals. For this, companies are increasingly turning to implementing new technological developments in their recruitment and selection processes. This dissertation focuses on identifying the impact these technologies can cause, and what the best practices are for implementing them into recruitment processes, from the perspective of the internal recruiters. For this, a qualitative analysis was conducted through researching existing literature and conducting semi-structured interviews with recruiters. The results show that the implementation of automatic CV screening, asynchronous video interviewing and assessment games have a positive impact on recruitment processes, namely through increased accuracy of assessment, shortening the process duration, increasing diversity among recruits and enabling higher candidate pools. Companies are also focusing on increased software integration and gathering of recruitment metrics for continuous process improvement. For the successful implementation of these changes, recruiters see organizational culture as a key factor.A “guerra pelo talento” está a levar a que as organizações se foquem na agilidade do processo de recrutamento e em employer branding para recrutar os melhores candidatos. Para tal, as empresas estão a recorrer cada vez mais à implementação de novas tecnologias nos seus processos de recrutamento e seleção. Esta dissertação foca-se em identificar o impacto que estas tecnologias podem causar, e quais as melhores práticas para a sua integração em processos de recrutamento da perspetiva dos recrutadores internos. Para tal, uma análise qualitativa foi conduzida através da investigação da literatura existente e da condução de entrevistas semiestruturadas com recrutadores. Os resultados mostram que a implementação de triagem de CV automática, entrevistas em vídeo assíncronas e jogos de avaliação têm um impacto positivo em processos de recrutamento, nomeadamente através de um aumento na precisão das avaliações, encurtamento da duração do processo, aumento da diversidade entre recrutados e permitir um volume de candidaturas maior. As empresas também se estão a focar em aumentar a integração de software e a coleta de métricas de recrutamento para melhoria contínua dos processos. Para a implementação bem-sucedida destas alterações, os recrutadores vêm a cultura organizacional como um fator chave
Amazon's Alexa critical genealogy through the imagery of women and machine in science fiction cinema
In order to better understand the phenomenon of genderization of consumer
technologies, such as digital voice assistants (DVAs), present in the market today, this
dissertation examines the possible sociocultural intersections between gender and technology
present in the imaginary of science fiction cinema. To do so, a Foucauldian discourse analysis
was conducted on ten feature films in this artistic genre, which is very dear to feminism,
especially as of its third wave, drawing an intertextual parallel with the responses programmed
into some of the most popular DVAs available today, such as Amazon’s Alexa and Apple’s Siri.
This dissertation challenges the argument that the genderization of technology is a
phenomenon as recent as these new technologies and that it can be explained only from a
user experience point of view. With this objetive in mind, we trace a genealogy of Alexa based
on the ideas proposed by Michel Foucault, in an attempt to expose the power games behind
these gender constructions inside and outside of cinema. In this sense, we identified and
examined three main categories of discourse analysis that are present and repeated not only in
the filmic sample, but also in the DVAs used daily by millions of consumers around the world.
The study points to the need to overcome gender barriers in not only technical, but also
sociocultural, access to technologies in general.Com o objetivo de melhor compreender o fenômeno de genderização de tecnologias de
consumo presentes hoje no mercado, como as digital voice assistants (DVAs), esta dissertação
examina as possíveis interseções socioculturais entre gênero e tecnologia presentes no
imaginário do cinema de ficção científica. Para isso, foi realizada uma análise de discurso
foucauldiana em dez filmes de longa metragem deste gênero artístico, que é muito caro ao
feminismo especialmente a partir da sua terceira onda, estabelecendo um paralelo intertextual
a partir das respostas programadas em algumas das mais populares DVAs disponíveis
atualmente, como Alexa, da Amazon, e Siri, da Apple. Esta dissertação desafia o argumento de
que a genderização da tecnologia é um fenômeno tão recente quanto essas novas tecnologias
e que pode ser explicado apenas do ponto de vista da experiência do usuário. Para este efeito,
traça-se uma genealogia da Alexa com base nas ideias propostas por Michel Foucault, expondo
os jogos de poder por detrás dessas construções de gênero dentro e fora do cinema. Nesse
sentido, foram identificadas e examinadas três categorias principais de análise de discurso que
estão presentes e se repetem não apenas na amostra fílmica, mas também nas DVAs utilizadas
diariamente por milhões de consumidores ao redor do mundo. O estudo aponta para a
necessidade de superação das barreiras de gênero no acesso não apenas técnico, mas também
sociocultural, às tecnologias de forma geral
Distribuição dos algodoeiros no nordeste do Brasil.
Zoneamento do nordeste para a cultura algodoeira.bitstream/item/33345/1/DISTRIBUICAO-DOS-ALGODOEIROS.pd
Bidirectional mode-locked fiber ring laser
In modern day world, advances in technology are constantly pushing the limits of improvement in measurement accuracy. With each passing year, government agencies and contract companies increase investment in research of high precision, ultra sensitive, instruments. Over the last decade, advancements in ultrashort time scale optics have moved the field of metrology to the quantic realm. At this new scientific frontier, mode-locked lasers, with ultra sensitive phase measurement capabilities, have been playing an increasingly significant role. Among these highly sophisticated systems, mode-locked fiber lasers have been extensively explored in an unidirectional mode, while bidirectional remains a promising source for applications with considerable space for experimental innovation. In this project, efforts have been made to contribute to the scientific achievements in this area, with the implementation of an innovative approach for bidirectional mode-locking of fiber lasers, as a potential source for intra-cavity phase interferometry. It consists of a passively driven active mechanism that both stabilizes the laser and controls the location of the crossing points of the counter-circulating pulses. For that purpose, the idea has been developed in both a theoretical and experimental level, with the design, construction, and testing of a fiber ring laser scheme capable of producing stable and independent (frequency unlocked) bidirectional pulses. In this manuscript, the description of the research is presented in seven separate chapters. The first chapter provides an overview of the project itself, the advantages of the controlling mechanism and the importance and practical applications of bidirectional mode-locked fiber lasers. Chapter two introduces the theoretical background necessary to understand pulse propagation in a nonlinear, birefringent, gain saturated optical fiber. In chapter three, the passive mechanism behind bidirectional mode-locking is detailed. Chapter four deals with the systems modeling and computer simulation, and chapter five explains the functional aspects of the self-regenerative system used to stabilize and control the laser pulsing. Chapter six describes the experimental setup itself, and presents the measured data results. Finally, chapter seven summarizes all the work done, emphasizing the consequences of the experimental findings, and laying out the foundations for future work.\u2
Thermal equilibrium states in perturbative Algebraic Quantum Field Theory in relation to Thermal Field Theory
In the first part, we analyse the properties of an interacting, massive scalar field in an equilibrium state over Minkowski spacetime. We compare the known real- and imaginary-time formalisms of Thermal Field Theory with the recent construction by Fredenhagen and Lindner of a KMS state for perturbative interacting theories in the context of perturbative Algebraic Quantum Field Theory, in the adiabatic limit. In particular, we show that the construction of Fredenhagen and Lindner reduces to the real-time formalism only if the cocycle which intertwines between the free and interacting dynamics can be neglected. Furthermore, the Fredenhagen and Lindner construction reduces to the ordinary imaginary-time formalism if one considers the expectation value of translation invariant observables. We thus conclude that a complete description of thermal equilibrium for interacting scalar fields is generally obtained only by means of the state constructed by Fredenhagen and Lindner, which combines both formalisms of Thermal Field Theory. We also discuss the properties of the expansion of the Fredenhagen and Lindner construction in terms of Feynman diagrams in the adiabatic limit. We finally provide examples showing that the real- and the imaginary-time formalisms fail to describe thermal equilibrium already at first or second order in perturbation theory. The results presented in this part are summarized in (BDP19). In the second part, we discuss the so-called secular effects, characterized by the appearance of polynomial divergences in the large time limit of truncated perturbative expansions of expectation values in Quantum Field Theory. We show that, although such effect is an artifact of perturbation theory, and thus may not be obtained via exactly solving the dynamical equation if possible, they do not represent the breakdown of perturbation theory itself. Instead, we show that the polynomial divergences follow from a bad choice of state, and we present examples of states which produce expectation values whose perturbative expansion does not present secular effects. In particular, we point that it is possible to obtain non time-divergent perturbative expressions from thermal equilibrium states for the interacting theory. This last part is based on a research project which, by the time this thesis was written, had not been concluded yet
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