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- Os guias da montanha e sua contribuição para a sustentabilidade do territórioPublication . Carvalho, Mário João Paulo de Jesus; Ezequiel, GraçaA actividade turística é não só uma estratégia que contraria a rotina como também se assume como fonte de energia para situações de desgaste físico e mental do quotidiano. As viagens turísticas não só respondem às expectativas dos turistas que procuram lugares e experiências como contribuem para o desenvolvimento endógeno e competitivo dos destinos. A sustentabilidade desses espaços torna-se, pois, dependente de acções equilibradas, protagonizadas pelos diferentes agentes do fenómeno turístico. A redescoberta das potencialidades lúdicas e desportivas associadas à montanha impulsionam significativamente a atractividade turística daqueles espaços o que por outro lado significa a necessidade de se criar um modelo de desenvolvimento equilibrado e sustentado. Sem estratégias de auto-regulação e manutenção do equilíbrio ecológico os ambientes de montanha degradar-se-ão perdendo os valores diferenciadores que, em primeiro lugar, atraíram para aí o turismo. Por outro lado o aumento do número de clientes, mais exigentes, legitima a apropriação de novos lugares e a oferta de profissionais qualificados. Por acção dos guias de turismo, os visitantes podem assim desfrutar dos destinos numa perspectiva cultural, ambiental e social. A montanha do Pico, ponto mais alto de Portugal localizado na ilha do Pico - Açores, é um destino de montanha cuja forma dominante de visitação - ascensão ao Pico Pequeno - implica o acompanhamento de um Guia de Montanha. Os Guias de Montanha, responsáveis pela segurança dos visitantes na visita à montanha, têm que estar devidamente credenciados pelo Secretaria do Ambiente. A vulnerabilidade da Montanha do Pico acrescida da pressão exercida pelos visitantes faz do trabalho dos Guias de Montanha do Pico uma variável de excepcional importância para a sustentabilidade do território. Torna-se assim crucial conhecer a importância dos Guias de Montanha enquanto elementos interventivos no modelo onde a satisfação dos visitantes e o reforço da imagem do destino são prioridades. Nesse sentido levou-se a efeito um estudo relativamente à importância dos Guias de Montanha face à sustentabilidade do território. Para tal procedeu-se a uma revisão de literatura sobre o turismo de montanha, sustentabilidade dos territórios e turismo natureza. Com a aplicação das entrevistas semi-estruturadas aos Guias de Montanha do Pico processou-se uma análise qualitativa da oferta dos serviços prestados pelos Guias. Da aplicação das entrevistas concluiu-se que a actividade dos Guias de Montanha assume importante papel para a aquisição de competitividade e sustentabilidade dos territórios na Montanha do Pico - Açores.
- Inversion of the noisy Radon transform on SO(3) by Gabor frames and sparse recovery principlesPublication . Cerejeiras, Paula; Ferreira, Milton; Kaehler, Uwe; Teschke, GerdThe inversion of the one-dimensional Radon transform on the rotation group SO(3) is an ill-posed inverse problem that can be applied to X-ray tomography with polycrystalline materials. This paper is concerned with the development of a method to stably approximate the inverse of the noisy Radon transform on SO(3). The proposed approach is composed by basic building blocks of the coorbit theory on homogeneous spaces, Gabor frame constructions and variational principles for sparse recovery. The performance of the finally obtained iterative approximation is studied through several experiments.
- Comparative structural response of two steel bridges constructed 100 years apartPublication . Varum, Humberto; Sousa, Romain; Delgado, Walter; Fernandes, Catarina; Costa, Aníbal; Jara, José; Jara, Manuel; Álvarez, JesúsThis paper presents a comparative numerical analysis of the structural behaviour and seismic performance of two existing steel bridges, the Infiernillo II Bridge and the Pinhão Bridge, one located in Mexico and the other located in Portugal. The two bridges have similar general geometrical characteristics, but their construction is separated by one hundred years. 3D structural models of both bridges were developed and analyzed for various load cases and several seismic conditions. The results of the comparative analysis between the two bridges are presented in terms of natural frequencies and corresponding vibration modes, maximum stresses in the structural elements and maximum displacements. The study aimed at determining the influence of one century period in material properties, transverse sections and expected behaviour of two quite similar bridges. In addition, the influence of the bearing conditions in the global response of the Pinhão Bridge was evaluated.
- Endoscopy - Brief historical survey, developments and therapeuticsPublication . Libório, Ana; Couto, Sylvie; Cunha, António; Coelho, PauloRapid increase of elder population and the appearance of more diseases needs the creation of new medical devices, as minimal invasive as possible. Nowadays, the endoscopic capsule allows good image and much less stress and pain to the patient than traditional endoscopic catheters. The endoscopy to become as developed as today had many improvements. We present on this paper a brief survey of the historical background of equipment developments, some of the most commonly used endoscopic procedures, their drawbacks and virtues.
- On using crowdsourcing and active learning to improve classification performancePublication . Costa, Joana; Silva, Catarina; Antunes, Mário; Ribeiro, BernardeteCrowdsourcing is an emergent trend for general-purpose classification problem solving. Over the past decade, this notion has been embodied by enlisting a crowd of humans to help solve problems. There are a growing number of real-world problems that take advantage of this technique, such as Wikipedia, Linux or Amazon Mechanical Turk. In this paper, we evaluate its suitability for classification, namely if it can outperform state-of-the-art models by combining it with active learning techniques. We propose two approaches based on crowdsourcing and active learning and empirically evaluate the performance of a baseline Support Vector Machine when active learning examples are chosen and made available for classification to a crowd in a web-based scenario. The proposed crowdsourcing active learning approach was tested with Jester data set, a text humour classification benchmark, resulting in promising improvements over baseline results.
- Estimation of dielectric concrete properties from power measurements at 18.7 and 60 GHzPublication . Feitor, Bruno; Caldeirinha, Rafael; Fernandes, Telmo, Telmo Rui Carvalhinho Cunha, Telmo R.; Ferreira, David; Leonor, NunoIn this paper, microwave and millimetre wave reflection coefficient measurements at 18.7 and 60 GHz are presented for a group of concrete slabs, in which only the thickness of the gravel present inside is varied. An empirical reflection coefficient value is determined using both reflected and LOS power measurements. A concrete slab with no gravel is used as a reference. The measurement results show the dependence of the reflection coefficient with the thickness of the gravel inside the slab. The measurement results allow for the appropriate extraction of dielectric properties of the materials under study.
- Complexity control of high efficiency video encoders for power-constrained devicesPublication . Correa, Guilherme; Assunção, Pedro; Agostini, Luciano; Cruz, Luis da SilvaThe emerging High Efficiency Video Coding (HEVC) standard is expected to require much more processing power than its predecessors due to the higher algorithmic complexity of new coding tools and associated data structures. This paper proposes a novel complexity control method for the near future HEVC encoders running on power-constrained devices. The proposed method is based on a decision algorithm that dynamically adjusts the depth of the Coding Units (CU) defined by quad-tree structures. New evidence about the relationship between CU depth and coding complexity is used to selectively constrain the CU depth in order to not exceed a predefined complexity target. The experimental results show that the encoder computational complexity can be downscaled by up to 60% at the cost of negligible loss of rate-distortion (RD) performance. The proposed method finds application in the near future multimedia portable devices using HEVC codecs1.
- Entrepreneurial orientation, exploitative and explorative capabilities, and performance outcomes in export markets: A resource-based approachPublication . Lisboa, Ana; Skarmeas, Dionysis; Lages, CarmenInnovation is critical to the growth and success of a firm. In an attempt to renew themselves and compete effectively in the global marketplace, firms must possess both technical and non-technical capabilities. Yet, the extant literature has mainly focused on technology and product development capabilities, disregarding other possible capability domains. This study investigates the role of market-related exploitative and explorative capabilities, together with product development ones, in the context of exporting. Drawing on the resource-based and organization learning theories, we examine the internal process through which entrepreneurial orientation influences performance in export markets and develop a model of entrepreneurial orientation–exploitative and explorative capabilities–advantage–performance relationships. The results indicate that entrepreneurial orientation is a precursor of exploitative and explorative product development and overseas market-related capabilities. The findings also suggest that product development explorative capabilities and overseas market-related exploitative capabilities have a positive effect on new product differentiation, which in turn enhances market effectiveness. Implications for scholars and practitioners are discussed along with suggestions for future research.
- Innovative capabilities: Their drivers and effects on current and future performancePublication . Lisboa, Ana; Skarmeas, Dionysis; Lages, CarmenThis study investigates the role of a firm's orientation, both customer and competitor, in driving innovative capabilities and the impact of those capabilities on a firm's current and future performance. The study's contribution is threefold in that it (1) examines market-related exploitative and explorative capabilities in conjunction with product development exploitative and explorative capabilities in terms of their strategic drivers (firm orientation) and performance outcomes; (2) disentangles the effects of exploitative and explorative capabilities on current and future performance; and (3) examines the role of innovative capabilities within the particularly relevant, but understudied, context of exporting. The findings suggest that, although customer orientation relates to both exploitative and explorative capabilities, competitor orientation relates only to exploitative capabilities. Exploitative capabilities affect current performance, whereas explorative capabilities affect future performance. These findings are of crucial relevance to export managers in their quest to identify, extend, and create new market opportunities.
- The effects of season and wrack subsidy on the community functioning of exposed sandy beachesPublication . Gonçalves, Sílvia; Marques, João C.Seasonality is an important component of the climate, known to influence several biological events that can be reflected in community structure and organization. However, sandy beach macrofaunal community ecological studies are frequently based on snapshot sampling events, neglecting this important dimension and its effects. In the present study, the effects of seasons and wrack subsidies on macrofaunal communitie’s function of two similar exposed sandy beaches of Portugal was monitored for approximately 18 months by sampling all the beach area, from the shoreline to the base of the dunes. The study assessed the beach physical environment, community density and composition, trophic structure, secondary production of key species and the potential relationships between biological data and environmental parameters. Seasonality, particularly temperature variations, and the interaction between seasons and the beach zones (supralittoral vs. intertidal areas) had a strong influence on the communities, promoting a differential utilization of the beach by several species. Seasons also shaped the density of trophic groups, with consequences in community composition and function. Differences between beaches were observed on wrack subsidy, community composition and relative contribution of the dominant species, but the trophic structure was stable and dominated by scavengers. Talitrus saltator was the most productive key species, and the contribution of the resident key species regarding secondary productions and standing stocks was different between beaches. Wrack quantity and deposition frequency on the beach had a positive influence on several faunal descriptors such as density and number of species of various functional groups. The present study also highlights the clear dependence of macrofauna of exposed sandy beaches on the wrack subsidies brought ashore by the tides, illustrating their role on community organization regarding several wrack-associated species and not only scavengers.