2016
Authors
Oliveira, PBdM; Pires, EJS;
Publication
Interdisciplinary Perspectives on Contemporary Conflict Resolution
Abstract
2016
Authors
Tabassum, S; Gama, J;
Publication
SAC
Abstract
The problem of analyzing massive graph streams in real time is growing along with the size of streams. Sampling techniques have been used to analyze these streams in real time. However, it is difficult to answer questions like, which structures are well preserved by the sampling techniques over the evolution of streams? Which sampling techniques yield proper estimates for directed and weighted graphs? Which techniques have least time complexity etc? In this work, we have answered the above questions by comparing and analyzing the evolutionary samples of such graph streams. We have evaluated sequential sampling techniques by comparing the structural metrics from their samples. We have also presented a biased version of reservoir sampling, which shows better comparative results in our scenario. We have carried out rigorous experiments over a massive stream of 3 hundred million calls made by 11 million anonymous subscribers over 31 days. We evaluated node based and edge based methods of sampling. We have compared the samples generated by using sequential algorithms like, space saving algorithm for finding topK items, reservoir sampling, and a biased version of reservoir sampling. Our overall results and observations show that edge based samples perform well in our scenario. We have also compared the distribution of degrees and biases of evolutionary samples.
2016
Authors
Horta, IM; Camanho, AS; Dias, TG; Niza, S;
Publication
EXPLORING SERVICES SCIENCE (IESS 2016)
Abstract
This paper develops an innovative methodology to assess municipal performance concerning the environmental efficiency of new buildings construction, focusing on the consumption of different types of materials. This study aims to support local governments in the definition of policies for improvements in service provision based on the results of a benchmarking study. The methodology developed includes two stages. The first step concerns the evaluation of municipal environmental efficiency using Data Envelopment Analysis and the identification of factors that may explain different levels of performance. The second step enables the classification of municipalities in terms of the efforts required to achieve environmental efficiency. For this purpose, we used clustering analysis, namely the k-means algorithm. To illustrate the methodology developed, we analyzed the data of the major materials used in the construction of new buildings (metals, non-metallic minerals, fossil fuels, and biomass) in the municipalities of Lisbon metropolitan area between 2003 and 2009. The study revealed that the environmental efficiency of new buildings construction varies considerably among municipalities, suggesting a high potential for performance improvement.
2016
Authors
Pereira, A; Familiar, A; Moreira, B; Terroso, T; Carvalho, P; Corte Real, L;
Publication
IMAGE ANALYSIS AND RECOGNITION (ICIAR 2016)
Abstract
Tracking objects in video is a very challenging research topic, particularly when people in groups are tracked, with partial and full occlusions and group dynamics being common difficulties. Hence, its necessary to deal with group tracking, formation and separation, while assuring the overall consistency of the individuals. This paper proposes enhancements to a group management and tracking algorithm that receives information of the persons in the scene, detects the existing groups and keeps track of the persons that belong to it. Since input information for group management algorithms is typically provided by a tracking algorithm and it is affected by noise, mechanisms for handling such noisy input tracking information were also successfully included. Performed experiments demonstrated that the described algorithm outperformed state-of-the-art approaches.
2016
Authors
Gouvinhas, I; Dominguez Perles, R; Machado, N; Carvalho, T; Matos, C; Barros, AIRNA;
Publication
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
Abstract
The nutritional properties and safety of olive oil are strongly dependent on the content of mineral nutrients and trace elements. Hence, this work assesses the content for quality and toxic metals of olive oils from three major Portuguese cultivars ('Galega', 'Cobran double dagger osa' and 'Picual') obtained from olives in different ripening stages. This evaluation was achieved by flame atomic spectrometry and atomic absorption in a graphite furnace, depending on the metal to be analysed. The results showed mean concentrations of the mineral nutrients Ca and Mg of 20.00 A mu g g(-1), and K and Na of 40.00 and 170.00 A mu g g(-1), respectively, while the trace elements Fe, Co, Cu, Mn, Zn and Ni had mean values of 0.53, a parts per thousand currency sign 0.01, 0.33, 0.10, 1.09 and 0.64 A mu g g(-1), respectively. The mean content of the toxic metals Al, Cd, Pb and As were 27.46, 0.03, 0.09 and 0.36 A mu g g(-1), respectively, which were according to the values proposed by European regulations. The evaluation of the data obtained by partial least square regression allowed the identification of the minerals with the strongest potential to discriminate between the season (Na, Cu, Zn and Ni) and the cultivar employed in the olive oil performance (Fe and Mn).
2016
Authors
Silva, I; Almeida, C; Teixeira, A; Oliveira, J; Vasconcelos, C;
Publication
CLINICAL RHEUMATOLOGY
Abstract
Impaired angiogenesis in systemic sclerosis has a major role in tissue injury pathogenesis. Our objective was to determine whether angiogenic biomarkers (vascular endothelial growth factor (VEGF), endoglin, and endostatin) are related to microvascular damage and to determine their predictive value for new digital ulcers (DU). The main outcome of the study was the occurrence of a new digital ulcer during 3-year follow-up. This prospective longitudinal study was performed between October 2011 and December 2014. Seventy-seven patients definitely diagnosed with systemic sclerosis where divided into two groups: those with active DU at baseline and those with no DU until enrollment. Patients were matched by sex and age with healthy controls. Serum levels of VEGF, endoglin, and endostatin were measured at enrollment, and several nailfold videocapillaroscopies were performed during the 3-year follow-up. Serum levels of VEGF were lower (245.06, 158.68-347.33; p < 0.001) and those of endoglin were higher (3.013, 1.463-7.023; p < 0.001) in patients with active DU than those with no DU history (339.49, 202.00-730.93/1.879, 0.840-3.280), and they were higher than those found in controls (178.030, 101.267-222.102)/0.277, 0.154-0.713), respectively. No differences in endostatin levels were found between groups (p = 0.450). Endoglin was the only biomarker significantly different (p = 0.031) between patients with diffuse versus limited systemic sclerosis and between early, active, and late patterns (p = 0.020). VEGF was identified as an independent predictor for the development of new DU. Our study confirmed the relationship between angiogenic vascular biomarkers and the occurrence of DU. Endoglin and VEGF serum levels are potential risk factors, and VEGF has a predictive value for the occurrence of new DU.
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