895 resultados para Trudinger-Moser Inequality


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Critical Discourse Analysis (CDA) has probably made the most comprehensive attempt to develop a theory of the inter-connectedness of discourse, power and ideology and is specifically concerned with the role that discourse plays in main-taining and legitimizing inequality in society. While CDA’s general thrust has been towards the analysis of linguistic structures, some critical discourse analysts have begun to focus on multimodal discourses because of the increasingly impor-tant role these play in many social and political contexts. Still, a great deal of CDA analysis has remained largely monomodal. The principal aim of this chapter is therefore to address this situation and demonstrate in what ways CDA can be deployed to analyse the ways that ideological discourses can be communicated, naturalised and legitimated beyond the linguistic level. The chapter also offers a rationale for a multimodal approach based on Halliday’s Systemic Functional Linguistics (SFL), by which it is directly informed

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This paper examines the relationship between stature and later life health in 6 emerging economies, each of which are expected to experience significant increases in the mean age of their populations over the coming decades. Using data from the WHO Study on Global Ageing and Adult Health (SAGE) and pilot data from the Longitudinal Ageing Study in India (LASI), I show that various measures of health are associated with height, a commonly used proxy for childhood environment. In the pooled sample, a 10 cm increase in height is associated with between a 2 and 3 percentage point increase in the probability of being in very good or good self-reported health, a 3 percentage point increase in the probability of reporting no difficulties with activities of daily living or instrumental activities of daily living, and between a fifth and a quarter of a standard deviation increase in grip strength and lung function. Adopting a methodology previously used in the research on inequality, I also summarise the height-grip strength gradient for each country using the concentration index, and provide a decomposition analysis.

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Mental health social workers have a central role in providing support to people with mental health problems and in the use of coercion aimed at dealing with risk. Mental health services have traditionally focused on monitoring symptoms and ascertaining the risks people may present to themselves and/or others. This well-intentioned but negative focus on deficits has contributed to stigma, discrimination and exclusion experienced by service users. Emerging understandings of risk also suggest that our inability to accurately predict the future makes risk a problematic foundation for compulsory intervention. It is therefore argued that alternative approaches are needed to make issues of power and inequality transparent. This article focuses on two areas of practice: the use of recovery based approaches, which promote supported decision making and inclusion; and the assessment of a person’s ability to make decisions, their mental capacity, as a less discriminatory gateway criterion than risk for compulsory intervention.

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This paper provides a comparative analysis of working class consumer credit in Britain and France from the early twentieth century through to the 1980s. It indicates a number of similarities between the two nations in the earlier part of the period: in particular, in the operation of doorstep credit systems. For the British case study, we explore consumer finance offered by credit drapers (sometimes known as tallymen) whilst in France the paper explores a similar system that functioned in the coalmining communities around the city of Lens. Both methods operated on highly socialised relationships that established the trust on which credit was offered and long-term creditor/borrower relationships established. In the second part of the paper, we analyse the different trajectories taken in post-war France and Britain in this area of working class credit. In France this form of socialized credit gradually dwindled due to factors such as ‘Bancarisation’, which saw the major banks emerge as modern bureaucratized providers of credit for workers and their families. In contrast, in Britain the tallymen (and other related forms of doorstep credit providers) were offered a new lease of life in the 1960s and 1970s. This was a period during which British credit providers utilised multiple methods to evade the hire purchase controls put in place by post-war governments. Thus, whilst the British experience was one of fragmented consumer loan types (including the continuation of doorstep credit), the French experience (like elsewhere in Europe) was one of greater consolidation. The paper concludes by reflecting on the role of these developments in the creation of differential experiences of credit inclusion/exclusion in the two nations and the impact of this on financial inequality.

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This paper examines the impact of territoriality on young people’s everyday experiences in Northern Ireland’s segregated communities. It shows how urban encounters are reproduced through negotiating differences and the ways in which living in divided communities escalates moods of social inequality and spatial imbalances. The empirical study undertaken in the city of Derry shows how individuals and community groups position and identify themselves under the impact of social segregation. Building on Gordon Allport’s (1954) theories of contact, I explain how people in Derry have established their own sense of belonging, of who they are, based on their group memberships which eventually became an important source of pride and selfesteem. They also presented their own intertextual references as a cause of routine survival and belonging, allowing them to be more constructive about their future. Under deeply rooted segregation in Northern Ireland, the young generations are sought to provide lasting change to foster peace and integration between the two communities.

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In this paper, we study the achievable ergodic sum-rate of multiuser multiple-input multiple-output downlink systems in Rician fading channels. We first derive a lower bound on the average signal-to-leakage-and-noise ratio by using the Mullen’s inequality, and then use it to analyze the effect of channel mean information on the achievable ergodic sum-rate. A novel statistical-eigenmode space-division multiple-access (SESDMA) downlink transmission scheme is then proposed. For this scheme, we derive an exact analytical closed-form expression for the achievable ergodic rate and present tractable tight upper and lower bounds. Based on our analysis, we gain valuable insights into the system parameters, such as the number of transmit antennas, the signal-to-noise ratio (SNR) and Rician K-factor on the system sum-rate. Results show that the sum-rate converges to a saturation value in the high SNR regime and tends to a lower limit for the low Rician K-factor case. In addition, we compare the achievable ergodic sum-rate between SE-SDMA and zeroforcing beamforming with perfect channel state information at the base station. Our results reveal that the rate gap tends to zero in the high Rician K-factor regime. Finally, numerical results are presented to validate our analysis.

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This article argues that the UK government’s Community Resilience programme is less about responding to disasters and more a matter of producing community and governing its behaviour. The passing over of responsibility to local volunteers and organisations is not only about empowerment, but forming identities and relationships that can be more efficiently managed and directed. However, this attempt is hamstrung by its basis in a nostalgic, romantic view of community and the effacement of poverty and inequality as central to the vulnerability/resilience binary. The effect may be a more intense government of communities rather than their empowerment through resilience.

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AIM: To evaluate the association between various lifestyle factors and achalasia risk.

METHODS: A population-based case-control study was conducted in Northern Ireland, including n= 151 achalasia cases and n = 117 age- and sex-matched controls. Lifestyle factors were assessed via a face-to-face structured interview. The association between achalasia and lifestyle factors was assessed by unconditional logistic regression, to produce odds ratios (OR) and 95% confidence interval (CI).

RESULTS: Individuals who had low-class occupations were at the highest risk of achalasia (OR = 1.88, 95%CI: 1.02-3.45), inferring that high-class occupation holders have a reduced risk of achalasia. A history of foreign travel, a lifestyle factor linked to upper socio-economic class, was also associated with a reduced risk of achalasia (OR = 0.59, 95%CI: 0.35-0.99). Smoking and alcohol consumption carried significantly reduced risks of achalasia, even after adjustment for socio-economic status. The presence of pets in the house was associated with a two-fold increased risk of achalasia (OR = 2.00, 95%CI: 1.17-3.42). No childhood household factors were associated with achalasia risk.

CONCLUSION: Achalasia is a disease of inequality, and individuals from low socio-economic backgrounds are at highest risk. This does not appear to be due to corresponding alcohol and smoking behaviours. An observed positive association between pet ownership and achalasia risk suggests an interaction between endotoxin and viral infection exposure in achalasia aetiology.

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Neighborhoods across the globe are becoming increasingly ‘divers’, yet we still find their urban encounters reproduced through negotiating differences that escalates moods of social inequality and spatial imbalances. Research on ethnic division also stresses the spatial aspects of their production as shared urban spaces are mostly signified in the literature as ethnic ‘enclaves’. Territoriality and place attachment, in this sense, has a wide impact on the people’s everyday encounters while experiencing segregation. These historical narratives have produced communities that exhibit high levels of intracommunity relations and localized networking. This article investigates how youngster generations in Northern Ireland perceive, accept and respond to their differences, or perhaps how they act against it, to push the boundaries towards more diversity. In fact, the spatial and temporal encounters that occur among one community and the ‘Other’ signify a sort of negotiations and being more constructive about the future. The argument maintains that territoriality and place attachment has a wide impact on the young people’s everyday experiences. The empirical study shows how individuals and community groups position and identify themselves under the impact of social segregation. Building on social identity theories, I explain how people in Derry have established their own sense of belonging, of who they are, based on their group memberships which eventually became an important source of pride and self-esteem.

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In this brief, a hybrid filter algorithm is developed to deal with the state estimation (SE) problem for power systems by taking into account the impact from the phasor measurement units (PMUs). Our aim is to include PMU measurements when designing the dynamic state estimators for power systems with traditional measurements. Also, as data dropouts inevitably occur in the transmission channels of traditional measurements from the meters to the control center, the missing measurement phenomenon is also tackled in the state estimator design. In the framework of extended Kalman filter (EKF) algorithm, the PMU measurements are treated as inequality constraints on the states with the aid of the statistical criterion, and then the addressed SE problem becomes a constrained optimization one based on the probability-maximization method. The resulting constrained optimization problem is then solved using the particle swarm optimization algorithm together with the penalty function approach. The proposed algorithm is applied to estimate the states of the power systems with both traditional and PMU measurements in the presence of probabilistic data missing phenomenon. Extensive simulations are carried out on the IEEE 14-bus test system and it is shown that the proposed algorithm gives much improved estimation performances over the traditional EKF method.

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Este trabalho, no âmbito da Didáctica da Matemática, foca-se no estudo de abordagens alternativas de ensino e aprendizagem da Geometria Euclidiana, no Ensino Secundário, no sentido de promover níveis estruturados do pensamento matemático. Em particular, as potencialidades do recurso a outros modelos de Geometria Plana (e.g. Geometria Hiperbólica, Geometria do Motorista de Táxi) em relação a este problema serão investigadas. A opção pelo Ensino Secundário deve-se ao facto de se tratar de um nível de ensino onde se regista uma elevada taxa de insucesso escolar (especialmente no 10º ano) e onde é notório o abismo existente, entre o ensino Secundário e Universitário, no âmbito do raciocínio lógico - dedutivo. O trabalho a desenvolver pretende aprofundar o estudo de questões ligadas à natureza do conhecimento envolvido que estarão na base de decisões, tais como: Quais os processos que vão ser ensinados? Que processos queremos que os alunos dominem? E, por outro lado, ter em conta que se pretende desenvolver capacidades de ordem superior, significando que o ensino da Matemática deve dirigir-se para níveis elevados de pensamento, tais como: resolução de problemas; comunicar matematicamente; raciocínio e demonstração. No currículo de matemática para o Ensino Básico e Secundário tem-se negligenciado a demonstração matemática, contribuindo para que exista uma desconformidade entre os graus de ensino, secundário e universitário. Muitas vezes as abordagens de ensino centram-se na verificação de resultados e desvalorizam a exploração e explicação (Villiers, 1998). Actualmente, assiste-se a uma tendência para retomar o raciocínio lógico - dedutivo. O principal objectivo desta investigação é analisar ambientes de aprendizagem em que os alunos sejam solicitados a resolver problemas de prova em contextos diversificados e, de uma forma mais geral promover o desenvolvimento do raciocínio dedutivo e uma visão mais alargada do conhecimento matemático. Em particular, a abordagem de problemas de prova num contexto de geometria não Euclidiana, com recurso a artefactos e a software de geometria dinâmica, será investigada.

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O volume reúne um conjunto de textos de autores consagrados no campo da psicologia social e neles o leitor encontrará alguns dos aprofundamentos mais recentes da teoria iniciada em 1961 por Serge Moscovici. “Dada sua variedade e abrangência intelectual, as conferências se debruçam sobre o marco conceitual e empírico da teoria das representações sociais, expressando não apenas aquilo que lhe é distinto enquanto abordagem psicossocial, mas também a produtividade de suas linhas de comunicação com as sociedades vivas. Surpreendentes e inspiradoras, estas vozes nos revelam o marco e a marca da teoria das representações sociais: a dinamicidade dos saberes sociais, sua diversidade interna, e, sobretudo, sua conexão profunda com as condições socioculturais dos lugares e tempos que lhes produzem. Para os que já conhecem e trabalham com a teoria, o livro oferece uma oportunidade única de escutar grandes mestres delineando e avançando seu arcabouço teórico e sua aplicação empírica. Para os que a encontrarão aqui pela primeira vez, será evidente a conexão entre representações sociais e sentido, o problema da significação e variabilidade da ordem simbólica, a importância dos saberes do cotidiano e do senso comum e a atenção empírica aos grandes problemas da contemporaneidade”.

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As comunicações quânticas aplicam as leis fundamentais da física quântica para codificar, transmitir, guardar e processar informação. A mais importante e bem-sucedida aplicação é a distribuição de chaves quânticas (QKD). Os sistemas de QKD são suportados por tecnologias capazes de processar fotões únicos. Nesta tese analisamos a geração, transmissão e deteção de fotões únicos e entrelaçados em fibras óticas. É proposta uma fonte de fotões única baseada no processo clássico de mistura de quatro ondas (FWM) em fibras óticas num regime de baixas potências. Implementamos essa fonte no laboratório, e desenvolvemos um modelo teórico capaz de descrever corretamente o processo de geração de fotões únicos. O modelo teórico considera o papel das nãolinearidades da fibra e os efeitos da polarização na geração de fotões através do processo de FWM. Analisamos a estatística da fonte de fotões baseada no processo clássico de FWM em fibras óticas. Derivamos um modelo teórico capaz de descrever a estatística dessa fonte de fotões. Mostramos que a estatística da fonte de fotões evolui de térmica num regime de baixas potências óticas, para Poissoniana num regime de potências óticas moderadas. Validamos experimentalmente o modelo teórico, através do uso de fotodetetores de avalanche, do método estimativo da máxima verossimilhança e do algoritmo de maximização de expectativa. Estudamos o processo espontâneo de FWM como uma fonte condicional de fotões únicos. Analisamos a estatística dessa fonte em termos da função condicional de coerência de segunda ordem, considerando o espalhamento de Raman na geração de pares de fotões, e a perda durante a propagação de fotões numa fibra ótica padrão. Identificamos regimes apropriados onde a fonte é quase ideal. Fontes de pares de fotões implementadas em fibras óticas fornecem uma solução prática ao problema de acoplamento que surge quando os pares de fotões são gerados fora da fibra. Exploramos a geração de pares de fotões através do processo espontâneo de FWM no interior de guias de onda com suceptibilidade elétrica de terceira ordem. Descrevemos a geração de pares de fotões em meios com elevado coeficiente de absorção, e identificamos regimes ótimos para o rácio contagens coincidentes/acidentais (CAR) e para a desigualdade de Clauser, Horne, Shimony, and Holt (CHSH), para o qual o compromisso entre perda do guia de onda e não-linearidades maximiza esses parâmetros.

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“Branch-and-cut” algorithm is one of the most efficient exact approaches to solve mixed integer programs. This algorithm combines the advantages of a pure branch-and-bound approach and cutting planes scheme. Branch-and-cut algorithm computes the linear programming relaxation of the problem at each node of the search tree which is improved by the use of cuts, i.e. by the inclusion of valid inequalities. It should be taken into account that selection of strongest cuts is crucial for their effective use in branch-and-cut algorithm. In this thesis, we focus on the derivation and use of cutting planes to solve general mixed integer problems, and in particular inventory problems combined with other problems such as distribution, supplier selection, vehicle routing, etc. In order to achieve this goal, we first consider substructures (relaxations) of such problems which are obtained by the coherent loss of information. The polyhedral structure of those simpler mixed integer sets is studied to derive strong valid inequalities. Finally those strong inequalities are included in the cutting plane algorithms to solve the general mixed integer problems. We study three mixed integer sets in this dissertation. The first two mixed integer sets arise as a subproblem of the lot-sizing with supplier selection, the network design and the vendor-managed inventory routing problems. These sets are variants of the well-known single node fixed-charge network set where a binary or integer variable is associated with the node. The third set occurs as a subproblem of mixed integer sets where incompatibility between binary variables is considered. We generate families of valid inequalities for those sets, identify classes of facet-defining inequalities, and discuss the separation problems associated with the inequalities. Then cutting plane frameworks are implemented to solve some mixed integer programs. Preliminary computational experiments are presented in this direction.