86 resultados para distributed work


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article argues that the study of literary representations of landscapes can be aided and enriched by the application of digital geographic technologies. As an example, the article focuses on the methods and preliminary findings of LITESCAPE.PT—Atlas of Literary Landscapes of Mainland Portugal, an on-going project that aims to study literary representations of mainland Portugal and to explore their connections with social and environmental realities both in the past and in the present. LITESCAPE.PT integrates traditional reading practices and ‘distant reading’ approaches, along with collaborative work, relational databases, and geographic information systems (GIS) in order to classify and analyse excerpts from 350 works of Portuguese literature according to a set of ecological, socioeconomic, temporal and cultural themes. As we argue herein this combination of qualitative and quantitative methods—itself a response to the difficulty of obtaining external funding—can lead to (a) increased productivity, (b) the pursuit of new research goals, and (c) the creation of new knowledge about natural and cultural history. As proof of concept, the article presents two initial outcomes of the LITESCAPE.PT project: a case study documenting the evolving literary geography of Lisbon and a case study exploring the representation of wolves in Portuguese literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The way in which electricity networks operate is going through a period of significant change. Renewable generation technologies are having a growing presence and increasing penetrations of generation that are being connected at distribution level. Unfortunately, a renewable energy source is most of the time intermittent and needs to be forecasted. Current trends in Smart grids foresee the accommodation of a variety of distributed generation sources including intermittent renewable sources. It is also expected that smart grids will include demand management resources, widespread communications and control technologies required to use demand response are needed to help the maintenance in supply-demand balance in electricity systems. Consequently, smart household appliances with controllable loads will be likely a common presence in our homes. Thus, new control techniques are requested to manage the loads and achieve all the potential energy present in intermittent energy sources. This thesis is focused on the development of a demand side management control method in a distributed network, aiming the creation of greater flexibility in demand and better ease the integration of renewable technologies. In particular, this work presents a novel multi-agent model-based predictive control method to manage distributed energy systems from the demand side, in presence of limited energy sources with fluctuating output and with energy storage in house-hold or car batteries. Specifically, here is presented a solution for thermal comfort which manages a limited shared energy resource via a demand side management perspective, using an integrated approach which also involves a power price auction and an appliance loads allocation scheme. The control is applied individually to a set of Thermal Control Areas, demand units, where the objective is to minimize the energy usage and not exceed the limited and shared energy resource, while simultaneously indoor temperatures are maintained within a comfort frame. Thermal Control Areas are overall thermodynamically connected in the distributed environment and also coupled by energy related constraints. The energy split is performed based on a fixed sequential order established from a previous completed auction wherein the bids are made by each Thermal Control Area, acting as demand side management agents, based on the daily energy price. The developed solutions are explained with algorithms and are applied to different scenarios, being the results explanatory of the benefits of the proposed approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Existing wireless networks are characterized by a fixed spectrum assignment policy. However, the scarcity of available spectrum and its inefficient usage demands for a new communication paradigm to exploit the existing spectrum opportunistically. Future Cognitive Radio (CR) devices should be able to sense unoccupied spectrum and will allow the deployment of real opportunistic networks. Still, traditional Physical (PHY) and Medium Access Control (MAC) protocols are not suitable for this new type of networks because they are optimized to operate over fixed assigned frequency bands. Therefore, novel PHY-MAC cross-layer protocols should be developed to cope with the specific features of opportunistic networks. This thesis is mainly focused on the design and evaluation of MAC protocols for Decentralized Cognitive Radio Networks (DCRNs). It starts with a characterization of the spectrum sensing framework based on the Energy-Based Sensing (EBS) technique considering multiple scenarios. Then, guided by the sensing results obtained by the aforementioned technique, we present two novel decentralized CR MAC schemes: the first one designed to operate in single-channel scenarios and the second one to be used in multichannel scenarios. Analytical models for the network goodput, packet service time and individual transmission probability are derived and used to compute the performance of both protocols. Simulation results assess the accuracy of the analytical models as well as the benefits of the proposed CR MAC schemes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In recent years a set of production paradigms were proposed in order to capacitate manufacturers to meet the new market requirements, such as the shift in demand for highly customized products resulting in a shorter product life cycle, rather than the traditional mass production standardized consumables. These new paradigms advocate solutions capable of facing these requirements, empowering manufacturing systems with a high capacity to adapt along with elevated flexibility and robustness in order to deal with disturbances, like unexpected orders or malfunctions. Evolvable Production Systems propose a solution based on the usage of modularity and self-organization with a fine granularity level, supporting pluggability and in this way allowing companies to add and/or remove components during execution without any extra re-programming effort. However, current monitoring software was not designed to fully support these characteristics, being commonly based on centralized SCADA systems, incapable of re-adapting during execution to the unexpected plugging/unplugging of devices nor changes in the entire system’s topology. Considering these aspects, the work developed for this thesis encompasses a fully distributed agent-based architecture, capable of performing knowledge extraction at different levels of abstraction without sacrificing the capacity to add and/or remove monitoring entities, responsible for data extraction and analysis, during runtime.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article studies the cross-country differences in work ethic and claims that different political regimes transmitted different work ethics that still persist today. Using the World Values Survey and starting our political regime analysis in 1900, we find that Democratic regimes promote more effectively work relevance and competitiveness than Autocratic and Anocratic regimes, and that the political regime history of the country is more important than the present level of democracy. Moreover, we prove that this differences were transmitted through generations by parents, who optimally choose what work ethic to transmit taking into account their own values.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

RESUMO - A dor, incómodo ou desconforto ao nível músculo-esquelético, sobretudo devido a situações e/ou postos de trabalho com elevadas exigências ao nível postural, de aplicação de força, de repetitividade ou por incorrecta distribuição das pausas, é aceite como um indicador de situações de risco passíveis de se encontrarem na génese de lesões músculo- -esqueléticas ligadas ao trabalho (LMELT) (Stuart-Buttle, 1994). No sentido de avaliar a prevalência de sintomas de LME, efectuou-se um estudo numa grande empresa da indústria de componentes para automóveis na região de Lisboa durante o ano de 2001. Utilizou-se um instrumento de recolha de informação construído a partir de uma adaptação do questionário nórdico músculo-esquelético (QNM) (Kuorinka et al., 1987). Com o apoio do serviço de saúde ocupacional da referida empresa, o questionário foi entregue a todos os trabalhadores, obtendo-se uma taxa de respondentes de 63,2% (n = 574). A população em estudo é maioritariamente do sexo feminino (83,9%), tem idades compreendidas entre os 18 e os 65 anos e a classe modal situa-se entre os 26 e os 33 anos (23,3%). Os resultados evidenciam uma alta prevalência de sintomatologia de LME e diferenças significativas de sintomas entre as categorias profissionais (1) operadores de máquina de costura, (2) trabalhadores dos armazéns e de transporte de mercadorias e (3) trabalhadores da logística, qualidade e escritórios. Os operadores apresentam índices superiores e diferentes (p < 0,05) de sintomatologia nos últimos doze meses ao nível da região cervical, ombros, cotovelos, ancas/coxas, pernas/joelhos e tornozelos/pés e nos punhos nos últimos sete dias. No presente estudo, a análise dos dados obtidos parece indicar que a natureza e as características da actividade de trabalho do grupo profissional operadores de máquina de costura (flexão cervical > 20°, trabalho muscular predominantemente estático ao nível da articulação dos ombros, elevação dos membros superiores > 45°, ortostatismo e exigências elevadas ao nível dos punhos/mãos) estão implicadas no desencadear da sintomatologia auto- -referida.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper analyzes the Nova Student Portfolio (NSP) with the objective to understand performances of the fund. Each investment style has been analyzed (growth, value and momentum) in order to highlight what style allocation contributed positively and which had a negative impact. The results show that the team mainly invested in value stocks, which contributed positively but that its growth investments had a negative impact on the stock picking performance. The stock selection shows a major influence of the value investment style. A statistical approach shows that the market factor was the one explaining the most the NSP returns.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Native from south eastern Australia, Eucalyptus globulus is the main species in eucalypts plantations in Portugal. The most serious foliar disease in eucalypt plantations is linked to Mycosphaerella senso lato, which affects young trees in the juvenile phase foliage causing leaf necrosis. This disease results in reduced growth rate of the host and lower wood volume, thus causing significant productivity losses. The most common name for this disease was Mycosphaerella Leaf Disease that became inappropriate when most of the pathogens on eucalypts were re-distributed into several genera. The term "Eucalyptus Leaf Disease Complex" is now more appropriate. The overall aim of this thesis was to investigate the Eucalyptus Leaf Disease Complex in Portugal, focusing on species diversity, taxonomy and the role played by each species in the disease complex on Eucalyptus globulus. Literature on the Eucalyptus Leaf Disease Complex was reviewed and the species were distributed into several genera. A survey based on symptomatic leaves collected from several Eucalyptus globulus plantations and characterized by morphological and molecular tools provided an overview of species incidence and of the most frequent species in the disease complex. The present work reveals additional species of Mycosphaerella senso lato associated with eucalypt plantations in Portugal. Thus, five new records of Teratosphaeria and phylogenetically related species were added to the Iberian Peninsula, namely, Neodevriesia hilliana, for the first time on Myrtaceae; Quasiteratosphaeria mexicana, Teratosphaericola pseudoafricana, Teratosphaeria pluritubularis and Teratosphaeria lusitanica, a new species. Furthermore, new anamorphic structures were found and two new combinations were made. Regarding other genera, some species were observed for the first time, such as Cladosporium cladosporioides, Fusicladium eucalypti, Mycosphaerella madeirae, in the mainland. In addition to leave diseases, Teratosphaeria gauchensis was found causing a severe stem and trunk canker on Eucalyptus globulus. The aggressiveness of several species was compared to evaluate each species individually in the complex, permitting to distinguish different behaviours, from primary to secondary pathogens. Cladosporium cladosporioides, M. communis and M. lateralis, appeared to be more aggressive than Teratosphaeria nubilosa. In fact, contrary to the prevailing views on this disease complex, Teratosphaeria nubilosa is not the only species responsible for the disease, which clearly involves a complex of species acting together.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A comunicação estratégica poderá ser entendida como a comunicação alinhada com a estratégia global de uma organização para alcançar o seu posicionamento estratégico. Ou seja, para alcançar o sucesso, uma organização precisa de ter uma comunicação consistente com a sua identidade e, ao mesmo tempo, adequada ao seu público-alvo e ao tipo de sector onde se insere. Só desta forma consegue conquistar a confiança e fidelidade dos consumidores, essenciais para o alcance dos objectivos. Em relação à alteração comportamentos, é essencial que as empresas costruam uma estratégia de comunicação coerente e consistente, adaptando as mensagens e os públicos-alvo escolhidos. Neste âmbito da alteração de comportamentos, estudou-se neste trabalho a Sociedade Ponto Verde (SPV), uma associação portuguesa sem fins lucrativos, que actua no âmbito da gestão e reciclagem de resíduos de embalagens. Procurou estudar-se a evolução da sua comunicação ao longo dos anos e a forma como adaptou as suas mensagens, de forma a conseguir incutir na sociedade portuguesa a importância do comportamento de reciclagem de resíduos. Neste estudo, procedeu-se a uma análise individualizada de cada uma das campanhas de comunicação da SPV e, posteriormente, aplicou-se um inquérito por questionário, para verificar a eficácia das mesmas campanhas perante o público-alvo. A metodologia utilizada neste trabalho consistiu na distribuição de um inquérito por questionário online, que permitiu recolher uma amostra probabilística por conveniência. Em seguida, recolhidos e tratados os dados referentes às 482 respostas recebidas, utilizou-se o programa SPSS (Stastitical Package for the Social Sciences) para analisar, tratar e discutir os resultados obtidos. Estes resultados demonstraram que, de facto, não houve uma grande percentagem de inquiridos que se lembram das campanhas da SPV. Os resultados são positivos e não desmentem a qualidade e coerência das mensagens, mas a verdade é que a percentagem de indivíduos que não se lembra de algumas campanhas chega a ser elevada (em especial nas campanhas iniciais da organização, quando existia falta de uma estratégia coerente). Justifica-se este facto, em parte, pelo excesso de informação e estímulos a que as pessoas estão sujeitas, pelo que a informação que retêm não fica para sempre, acabando por dar lugar a outras informações. Os indivíduos são inconscientemente selectivos com a informação que processam e guardam, pois não seria possível guardar toda a informação que lhes é transmitida. No que diz respeito à comunicação estratégica que visa alterar uma atitude e, posteriormente, um comportamento, conclui-se que, no geral, o comportamento das pessoas inquiridas aparenta ter sido influenciado pela comunicação da SPV, caso contrário, as respostas afirmativas quanto à reciclagem e de concordância com algumas das afirmações teriam sido inferiores. Ou seja, mesmo reconhecendo o carácter um pouco enviesado da amostra (não deverá ser considerada representativa da população portuguesa), é possível dizer que a estratégia de comunicação da SPV (em especial a partir de 2005) foi eficiente. Palavras-

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In seeking to advance the possibility of justice, gender and postcolonial studies have argued for the importance of the study of masculinities, through the acknowledgment that a richer understanding of such gendered formations may provide the basis for recognition of the Other and that, left uncriticised, such formations may be continuously delineated by the reproduction of systems of domination. The current study finds as its object the representations of masculinities in J. M. Coetzee’s Boyhood (1997), Youth (2002) and Summertime (2009). As works of transition in terms of Coetzee’s oeuvre - post-apartheid and post-Disgrace - the trilogy provides an account of the development of a man through several stages of life. While portraying the tensions of different geographical and cultural locations, such as apartheid South Africa and the London of the Sixties, the trilogy articulates the various norms that impact in the formation of gender, particularly of masculinities, through a complex system of power relations. The adherence to such norms is never linear, as the trilogy provides imaginative accounts of the contradictions that assist in the formulation of gender, depicting both the allure and the terror that constitute hegemonic masculinity. Located in the intersection of gender and postcolonial studies, the present study is based on the works by Raewyn Connell on masculinities. Animated by such a critical framework, the main research question of the present study is whether the trilogy advances a notion of masculinity that differs from the traditional rigid model, that is, whether there is resistance to hegemonic masculinity and what the spaces inhabited by the subaltern are. It is suggested that the trilogy presents the reader with instances of resistance to normative formulations of masculinity, by contrasting domination with the possibility of justice, and advancing an understanding of the often fatal consequences of gender norms to one’s sense of being in the world.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Taking into account the fact that the sun’s radiation is estimated to be enough to cover 10.000 times the world’s total energy needs (BRAKMANN & ARINGHOFF, 2003), it is difficult to understand how solar photovoltaic systems (PV) are still such a small part of the energy source matrix across the globe. Though there is an ongoing debate as to whether energy consumption leads to economic growth or whether it is the other way around, the two variables appear correlated and it is clear that ensuring the availability of energy to match a country’s growth targets is one of the prime concerns for any government. The topic of centralized vs distributed electricity generation is also approached, especially in what regards the latter fit to developing countries needs, namely the lack of investment capabilities and infrastructure, scattered population, and other factors. Finally, Brazil’s case is reviewed, showing that the current cost of electricity from the grid versus the cost from PV solutions still places an investment of this nature with 9 to 16 years to reach breakeven (from a 25 year panel lifespan), which is too high compared to the required 4 years for most Brazilians. Still, recently passed legislation opened the door, even if unknowingly, to the development of co-owned solar farms, which could reduce the implementation costs by as much as 20% and hence reduce the number of years to breakeven by 3 years.