2,589 research outputs found
From geopolitical spill-over to tacit bargaining : Brazilian-African defence cooperation in the south atlantic (2003-2014)
Tese de doutoramento, Ciência Política (Relações Internacionais), Universidade de Lisboa, Instituto de Ciências Sociais, 2016This thesis contends that Brazilian-African relations have been predominantly framed under three main vectors of analysis, centred on political relations, economic interactions and the disbursement of development assistance. Such a thematic focus has led to a research gap in the form of defence cooperation ties between Brazil and African countries in the South Atlantic. Drawing from original gathered data and multiple interviews with key officials, it is demonstrated how Brazilian interpretations of its maritime borders incited a considerable expansion of such relations while providing a novel and systematised account of their intensity and diversity between 2003 and 2014. It is posited that the decision-making process over such transatlantic initiatives was primarily driven by geopolitical elements in a spill-over format and only secondarily by economic considerations. Similarly, it is argued that African countries regarded a combination of material and social factors, including technicalscientific support, abidance by rules from common international regimes and trust garnered amongst elites over the years, as decisive in their choice to engage with Brazil in this domain. The main findings underscore the need to adjust the current research focus on Brazilian-African relations while acknowledging brewing regional security-related dynamics in the South Atlantic
Brazil as a security actor in Africa: reckoning and challenges ahead
The story of Brazil's engagement in Africa is not necessarily novel, but its security activities on the continent still are. Often presented as by-products of the new South-South relations, they have resulted in substantial inroads towards the increased security capacity of several key countries. However, economic constraints, an unpredictable political context back home, and previously existing structural fragilities have led to a new, bleaker outlook for Brazil's position in Africa
Stretching the Limits? Strengths and Pitfalls of South Atlantic Security Regionalism
In the broader context of regional studies, the South Atlantic comes across as a singular, yet still understudied case study for the formation, evolution, and regression of security regionalism dynamics. More so when South Atlantic countries have come to engage in increased regionally focused interactions through wider defence co-operation ties. However, they have also steadfastly eschewed any kind of permanent structures and shared sovereignty over sensitive security issues. This article strives to ascertain the limits and prospects of these regional security dynamics in the South Atlantic. With the focal points set on both South American and African shores, I pinpoint key overtures in this area and question their contribution to advancing an overall regionalisation process. Despite shared threat perceptions and an absence of major intra-regional conflicts, I argue that South Atlantic security regionalism lacks a stable and permanent structure inasmuch as it lacks real autonomy from the dictums of external regional powers, thus leaving the transatlantic space still in flux
Dinámicas de seguridad en el Atlántico Sur: Brasil y Estados Unidos en África
Este artículo examina la creciente preocupación de la comunidad internacional por las nuevas dinámicas de seguridad que se están gestando en el Atlántico Sur y el potencial ascenso de esta área en la agenda internacional de seguridad. Sobre la base de viejas y nuevas amenazas con el telón de fondo del interés manifestado por países como Brasil y Estados Unidos hacia esta área específica, y haciendo hincapié en los intereses político-estratégicos de estos dos países en África, este texto ofrece una visión pertinente del contexto actual de seguridad, desde las posibilidades de competir a las oportunidades de cooperar entre todos los actores políticos involucrados
South–South cohesiveness versus South–South rhetoric: Brazil and Africa at the UN General Assembly
South–South relations have regained widespread interest in recent years, together with increasingly visible stances on international stages. Brazil’s interactions with the African continent, in particular, came to epitomise such a perception while sustaining an expectation of mutual alignment in several global issues. However, these assumptions still lack empirical corroboration. Drawing on United Nations General Assembly voting data for the 1991–2013 timeframe, this article questions a supposed South–South solidarity at the multilateral institution with the largest global representation and identifies key thematic axes that incite greater collective stances. The analysis further sheds light on whether or not a common South–South agenda has emerged over time.info:eu-repo/semantics/publishedVersio
Simulation framework for multigigabit applications at 60 GHz
This dissertation describes the implementation of a OFDM-based simulation framework
for multigigabit applications at 60 GHz band over indoor multipath fading channels.
The main goal of the framework is to provide a modular simulation tool designed
for high data rate application in order to be easily adapted to a speci c standard or
technology, such as 5G. The performance of OFDM using mmWave signals is severely
a ected by non-linearities of the RF front-ends. This work analyses the impact of RF
impairments in an OFDM system over multipath fading channels at 60 GHz using the
proposed simulation framework. The impact of those impairments is evaluated through
the metrics of BER, CFR, operation range and PSNR for residential and kiosk scenarios,
suggested by the standard for LOS and NLOS. The presented framework allows
the employment of 16 QAM or 64 QAM modulation scheme, and the length of the
cyclic pre x extension is also con gurable. In order to simulate a realistic multipath
fading channel, the proposed framework allows the insertion of a channel impulse response
de ned by the user. The channel estimation can be performed either using
pilot subcarriers or Golay sequence as channel estimation sequences. Independently of
the channel estimation technique selected, frequency domain equalization is available
through ZF approach or MMSE. The simulation framework also allows channel coding
techniques in order to provide a more robustness transmission and to improve the link
budget
Estilos de vida em idosas e níveis de atividade física: um estudo piloto
The International Physical Activity Questionnaire (IPAQ) is a standardized measure to estimate habitual practice of physical activities. Because of the specificity of different elderly’s life styles, and, consequently, modes of physical activity, the purpose of this pilot study was to analyze differences among ten regular gym practitioners (fitness group) (68,60±3,57 years of age) and ten Senior University students without gym practice (informal group) (71,30±5,54 years of age). The results showed that energy expenditure doesn’t depend solely on regular and controlled physical activity at a Fitness center, and that functional motor activity, as daily life active transportation and domestic and garden activities, resulted in similar energy expenditure. It’s suggested that programs combining energy expenditure and daily life motor activities is a good solution for quality of life enhancement, and an alternative to more standardized fitness practices.O Questionário Internacional de Atividade Física (IPAQ) é uma medida padronizada para estimar a prática habitual de atividades físicas. A finalidade deste estudo piloto foi analisar as diferenças entre dez praticantes regulares de ginásio (68,60 ± 3,57 anos de idade) e dez estudantes de uma Universidade Sénior sem atividade física formal (grupo informal) (71,30 ± 5,54 anos de idade). Os resultados mostraram que o dispêndio energético não depende unicamente da atividade física regular e controlada num centro de Fitness, e que a atividade motora funcional, como o transporte ativo e as atividades domésticas e de jardim, resultou em gastos energéticos semelhantes. Sugere-se que programas que combinem dispêndio energético e atividades motoras de vida diária são uma boa solução para a valorização da qualidade de vida e uma alternativa a práticas de Fitness mais padronizadas.info:eu-repo/semantics/publishedVersio
Política de defesa, política externa e grande estratégia do Brasil
Esta análise oferece uma perspetiva comparada das diferentes orientações estratégicas publicadas pelo Brasil na última década, com implicações ao nível do sector de defesa. O objetivo último consiste
em identificar alterações concretas recentes no planeamento estratégico brasileiro que sustentem a pretensão oficial de uma aproximação crescente entre os propósitos das políticas externa e de defesa nacionais.info:eu-repo/semantics/publishedVersio
Visão estratégica para Portugal: 2020-2030
O Instituto da Defesa Nacional (IDN) realizou um webinar no dia 29 de julho sobre o documento ‘Visão Estratégica para o Plano de Recuperação Económica de Portugal, 2020-2030’, redigido pelo Dr. António Costa Silva. Para além do autor, a sessão contou com as participações do Prof. Nuno Monteiro (Universidade de Yale) e do Prof. José Félix Ribeiro (IPRI-NOVA). A moderação ficou a cargo da Diretora do IDN, a Profª Helena Carreiras. Esta síntese representa uma súmula das intervenções de cada orador e do debate subsequente.info:eu-repo/semantics/publishedVersio
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