4,013 research outputs found
2D: Separação Bidimensional - 2 Dimensões Bioquímicas no Diagnóstico Alergológico
A sequência de procedimentos na identificação e caracterização bidimensional de alergénios
A logic for n-dimensional hierarchical refinement
Hierarchical transition systems provide a popular mathematical structure to
represent state-based software applications in which different layers of
abstraction are represented by inter-related state machines. The decomposition
of high level states into inner sub-states, and of their transitions into inner
sub-transitions is common refinement procedure adopted in a number of
specification formalisms.
This paper introduces a hybrid modal logic for k-layered transition systems,
its first-order standard translation, a notion of bisimulation, and a modal
invariance result. Layered and hierarchical notions of refinement are also
discussed in this setting.Comment: In Proceedings Refine'15, arXiv:1606.0134
Interpretability of deep neural networks at the model level
Deep neural networks (DNN) are very powerful tools but remain black boxes. Convolutional
neural networks (CNN) are a type of DNN specialized for certain tasks like image
classification, image segmentation and object detection, among others. These are the
focus of this study.
Because of the risks involved in applying these networks to areas such as medical
imaging and autonomous driving, it is important to understand the behaviour of CNNs,
in particular, how they reach their predictions. This will also be beneficial for their further
development.
Currently, most interpretability techniques are aimed at providing better understanding
of a single network instance and often explain only the prediction of a given individual
input example. However, for the same model (same architecture, task and
dataset), one can have many different hypotheses, simply by changing the initial conditions
(weights initialization). These sources of variability, between examples, for the
same hypothesis (model instance), and between hypothesis for the same example, are
not taken into account by the vast majority of current interpretability methods. This
opens the question whether there is consistency between hypothesis in the attributes the
interpretability diagnostics capture as being relevant for the predictions. In this work,
tools and methods were developed to analyse these two forms of variability. They were
applied to two interpretability diagnostics (saliency maps and sensitivity to occlusion)
for several models, with different architectures and tasks. Furthermore, it was shown
how they can be used to identify potential problems in the relevance of the attributes the
interpretability diagnostics capture in some of the scenarios studied. The method also
provides a means to assess possible strategies for mitigating this issue.As redes neuronais profundas são ferramentas muito poderosas, mas permanecem
caixas negras. As redes convolucionais são um tipo de redes neuronais profundas especialmente
adaptado a tarefas como a classificação de imagens, a segmentação de imagens e
a detecção de objectos, entre outras. Estas são o foco deste estudo.
Devido aos riscos associados à aplicação destas redes a áreas como a imagiologia
médica e a condução autónoma, é importante compreender o comportamento das redes
convolucionais, em particular, como chegam às suas previsões. Esta compreensão também
será benéfica para o seu crescente desenvolvimento.
Actualmente, a maioria das técnicas de interpretabilidade estão vocacionadas para
possibilitar uma maior compreensão de uma instância de rede em particular, e frequentemente
oferecem uma explicação para um exemplo em particular tirado do conjunto de
dados inicial. No entanto, para o mesmo modelo (mesma arquitectura, tarefa e conjunto
de dados), podem ter-se muitas hipóteses diferentes, pela simples mudança das condições
iniciais (inicialização dos pesos). Estas fontes de variabilidade, entre exemplos, para a
mesma hipótese (instância do modelo), e entre hipóteses para o mesmo exemplo, não são
tidas em conta na grande maioria das técnicas de interpretabilidade actuais. Isto abre
uma questão sobre se há consistência entre hipóteses quanto aos atributos que os diagnósticos
de interpretabilidade capturam como sendo relevantes para as previsões. Neste
trabalho, desenvolveram-se ferramentas e métodos para analisar estas duas formas de
variabilidade. Estas foram aplicadas a dois diagnósticos de interpretabilidade (mapas de
saliência e sensibilidade à oclusão) para vários modelos, com diferentes arquitecturas e
tarefas. Adicionalmente, mostrou-se como podem ser usadas para identificar potenciais
problemas quanto à relevância dos atributos capturados pelos diagnósticos de interpretabilidade
em alguns dos cenários estudados. Este método proporciona também uma forma
de avaliar possíveis estratégias para mitigar o problema
Water Pricing and Social Equity in Portuguese Municipalities
Water supply services are Services of General Interest (SGI), subject to specific public service obligations, such as universality, continuity, quality, affordability, transparency, and consumer protection. There is an extensive empirical literature on the design of optimal prices. However, these contributions tend to neglect the issue of universal service and equity concerning the volume of water for basic needs (the ‘essential minimum quantity’). Addressing this gap in the literature, and using empirical data for the Portuguese municipalities, this paper aims to evaluate whether income-related equity considerations are embodied in water supply Portuguese municipalities’ tariffs. Accordingly, essential minimum quantities of water for representative households are computed, and then compared with the lowest tariff block’s upper limit by water utility. Next, representative households are ranked by costs underlying essential minimum quantities and by income. This analysis also considers concentration curves and indexes which show that water bills are regressive, i.e., there is socioeconomic inequity favourable to the better-off representative households.Water Policy, Water Pricing, Social Equity, Efficient Water Use, Portugal.
INTERNAL ORGANIZATION OF A F&B COMPANY IN THE BOP CONTEXT
Base of Pyramid (BoP) is nowadays one of global management’s top issues. Although several studies were focused on developing economies and their markets behaviour, very few have worked on the internal organization dramaBoP, developing economies, strategy, value chain
By-catch de espadarte (Xiphias gladius) e tintureira (Prionace glauca) juvenil no palangre de superfície
Dissertação de Mestrado, Estudos Integrados dos Oceanos, 11 de Outubro 2013, Universidade dos Açores.A pesca de palangre de superfície apresenta elevadas rejeições e capturas acessórias, ou "by-catch", o que coloca graves problemas de gestão e conservação. Parte destes problemas reside na elevada captura de juvenis da espécie alvo, o espadarte (Xiphias gladius), e da principal espécie acessória, a tintureira (Prionace glauca). Com este trabalho pretendeu-se contribuir com informação ecológica relevante para avaliar possíveis medidas tecnológicas de mitigação destas capturas, nomeadamente modificações na arte quanto ao tipo de estralho, hora e profundidade do aparelho. Foram realizados 163 lances nas áreas dos Açores e Continente a bordo de três embarcações comerciais, com estralhos de aço e de monofilamento. 42 lances foram parcialmente instrumentados com temporizadores de anzol (7494 anzóis) e com registadores de temperatura e profundidade para determinar a hora e profundidade a que os indivíduos atacam o isco. A proporção média de juvenis de espadarte e tintureira capturados foi sempre superior a 50%, independentemente da área ou tipo de estralho. No entanto, nos 106 lances realizados nos Açores com estralhos de aço foram capturados 901 espadartes (CPUE de 8,1/1000 anzóis) e 6365 tintureiras (56,0/1000 anzóis), enquanto nos 28 lances com estralho de monofilamento foram capturados 590 espadartes (19,3/1000 anzóis) e 754 tintureiras (24,9/1000 anzóis). A proporção de juvenis foi semelhante nos dois tipos de estralho (espadarte 57,17% vs. 58,4%, tintureira 84,72% vs. 92,8%). Estes resultados mostram que o "bycatch" de juvenis das duas espécies é muito elevado, mas que o uso de monofilamento permite capturas de espadarte (a espécie alvo) significativamente superiores (2,4 vezes) e de tintureira significativamente inferiores (0.4 vezes) às obtidas com estralho de aço. A comparação de capturas entre áreas (apenas com estralhos de monofilamento) revelou também que as proporções de juvenis de ambas as espécies são comparáveis (espadarte 92,8 vs. 84,9%; tintureira 58,4 vs. 47,8%) mas que as capturas de tintureira são muito maiores na área Açores (CPUE média 24,9 vs. 3,1) enquanto as de espadarte são ligeiramente superiores (CPUE 19,3 vs. 15,6). A instrumentação da linha mostrou que ambas as espécies preferem as primeiras horas do período nocturno, mas que o espadarte ataca apenas durante a noite enquanto a tintureira ataca também durante o dia. Ambas as espécies atacaram entre os 30 e os 80 metros de profundidade. No entanto, não foram detectadas diferenças significativas no período do dia ou na profundidade entre adultos e juvenis para ambas as espécies. Estes resultados indicam que 1) a utilização de estralho de monofilamento em detrimento de estralho de aço poderá ser uma medida eficaz para redução de “by-catch” juvenil (e adulto) de tintureira permitindo ainda um aumento da captura de espadarte adulto, mas também de "bycatch" juvenil, e que 2) a hora e a profundidade de pesca do palangre não deverão constituir uma boa medida tecnológica de redução do "by-catch" de espadarte juvenil de ambas as espécies. Este trabalho suporta também a conclusão apontada por outros estudos de que a região dos Açores é uma área de maternidade importante para a tintureira no Atlântico norte.ABSTRACT: The pelagic longline fishery faces severe management and conservation problems related to its high levels of by-catch, juvenile swordfish (Xiphias gladius), the target species, and blue shark (Prionace glauca), the main accessory species. This project aimed at contributing with relevant ecological information to evaluate possible technological measures that could reduce this juvenile by-catch, namely type of leader (steel wire versus monofilament), hour and depth of hook setting. 163 sets were made onboard three commercial vessels around the Azores and mainland Portugal areas. 42 sets were partially instrumented with hook timers (7494 hooks) and Temperature Depth Recorders to study the hooking time and depth. Juveniles of both species were always above 50% of the catches per species, regardless of area and leader type. However, 901 swordfish (CPUE 8.1/1000 hooks) and 6365 blue shark (56.0/1000 hooks) were caught in 106 wire leader sets in the Azores area whereas the 28 monofilament sets caught 590 swordfish (19.3/1000 hooks) and 754 blue shark (24.9/1000 hooks). Proportion of juveniles was comparable between wire and mono sets for both species (57.2% vs. 58.4% and 84.7% vs. 92.8%, respectively). These results show that the use of mono leader allows significantly larger (2.4 times) catches of swordfish, the target species, whereas those of blue shark are significantly (0.4 times) lower than wire leader catches. Comparison between areas (mono leaders only) showed substantially higher catches of blue shark (avg. CPUE 24.9 vs. 3.1) and slightly higher catches of swordfish (CPUE 19.3 vs. 15.6) in the Azores for comparable proportions of juveniles in both species (swordfish 92.8 vs. 84.9%; blue shark 58.4 vs. 47.8%). The instrumented line showed a common preference o bite the hook in the first hours of the nightime period. However, swordfish bites the hook at night only whereas blue shark also bites during the day. Both species bitten the hooks at 30 to 80 meters depth. However, there were no significant differences between juvenile and adult in relation to depth or time of day. These results show that 1) using mono leader can be an effective measure to reduce juvenile (and adult) by-catch of blue shark while increasing swordfish catches but at the cost of also increasing juvenile swordfish by-catch, and that 2) time of day or depth of line setting don’t seem to be effective measures to reduce juvenile by-catch of both species. This work also supports previous findings that the Azores region is an important nursery for blue shark in the North Atlantic
Global Heritage Stone: Estremoz Marbles from Portugal
The Estremoz Anticline is a Variscan structure that has a Precambrian core and younger rocks aged Devonian Period. The marbles exploited as dimension stone occupy an intermediate stratigraphic position in the Cambrian age Volcano Sedimentary Sequence. The Variscan Orogeny was performed twice with different intensities under ductile and brittle tension fields. The Alpine Cycle also acts and causes more fracturing of the marbles.
The geological features imprinted in the marbles are beautiful aesthetic patterns highlighted when used as Dimension Stone. A long term continuous exploitation have been carried out since the Roman period. Pieces of art made with Estremoz Marbles were exported abroad and can be found in Museums and Archaeological Sites throughout Europe and North Africa countries. Present day Estremoz Marble’s production can be found all over the World. The marble based built heritage is omnipresent in the cities region.
The historical and widespread application of these marbles in National and International Monuments, some of them already part of the UNESCO World Heritage Sites, is a condition to propose them as Global Heritage Stone Resource for their international recognition.
References
Lopes, L. & Martins, R. 2014. Global Heritage Stone: Estremoz Marbles, Portugal. From: Pereira, D., Marker, B. R., Kramar, S., Cooper, B. J. & Schouenborg, B. E. (eds) Global Heritage Stone: Towards International Recognition of Building and Ornamental Stones. Geological Society, London, Special Publications, 407, http://dx.doi.org/10.1144/SP407.1
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