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de Oliveira L.M.M.,Federal University of Pernambuco | Montenegro S.M.G.L.,Federal University of Pernambuco | da Silva B.B.,Federal University of Pernambuco | Antonino A.C.D.,Federal University of Pernambuco | de Moura A.E.S.S.,IFPB
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2014

This study aimed to evaluate the real daily evapotranspiration - ETr by remote sensing and to compare it with ETr according to the Bowen ratio technique in the Tapacurá River basin, Pernambuco state, Brazil. The Surface Energy Balance Algorithm for Land (SEBAL) was used with data from Moderate Resolution Imaging Spectroradiometer (MODIS) and meteorological data obtained in a field experiment inside the basin from January 2010 to August 2011. The ETr from SEBAL ranged between 0 and 6 mm d-1, with the highest values registered in the Tapacurá reservoir and the smallest in urban areas inside the basin. The ETr from the Bowen ratio in a pasture area ranged from 3.6 to 4.9 mm d-1. The SEBAL provided good results of the daily evapotranspiration when compared with ETr estimated according to the Bowen ratio technique, resulting in Mean Absolute Error, Relative Error and Average Root Mean Square Error, respectively of 0.40 mm d-1; 9.63% and 0.51 mm d-1. It was concluded that, despite the intense presence of clouds in the region, it was possible to obtain the real daily evapotranspiration in Tapacurá River basin based on MODIS images with good precision. © 2014, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved.

Lourenco D.,IFPB | Coutinho S.,Federal University of Pernambuco
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The aim of the present article is to address a number of essential questions regarding children reading printed and digital texts. The objective is to develop a methodological procedure with children in the 3rd year of the 1st Cycle in Municipal Schools in the city of João Pessoa, in Paraíba, Brazil. The experiments have been produced to be implemented in schools. In Brazil, the subject of digital artifacts is still regarded as being precarious; however, the children surveyed have experience with digital artifacts and digital reading. © 2013 Springer-Verlag Berlin Heidelberg.

Pimentel B.A.,Federal University of Pernambuco | Da Costa A.F.B.F.,IFPB | De Souza R.M.C.R.,Federal University of Pernambuco
Proceedings of the International Joint Conference on Neural Networks | Year: 2015

The main property of kernel methods is that they can implicitly perform a nonlinear mapping of the input data into a high-dimensional space. This mapping allows to find a simpler structure within space without increasing the number of parameters increasing the clustering quality. Therefore, kernel methods may find better results for data arranged not linearly. Many methods presented in the literature only use point data. However, real problems need more complex representation. In this work, we propose a new kernel-based fuzzy method using feature space metric for interval-valued data. Moreover, a comparative study between input space and feature space is set up in this paper. In order to evaluate the performance of the proposed method, experiments with synthetic and real interval data set were carried out. © 2015 IEEE.

Oliveira J.F.F.D.,Anhanguera | Regis C.D.M.,IFPB | Alencar M.S.D.,Iecom
Procedia Computer Science | Year: 2015

Considering the current requirements of available bandwidth due to the increase of video transmissions, a new video encoding standard was released by the ISO/IEC MPEG and ITU-T VCEG groups. The main feature of the High Efficiency Video Coding (HEVC) is to enable improved compression performance relative to existing standards in the range of 50% bit-rate reduction for equal perceptual video quality. Although the PSNR metric can show good results, it is not sensitive to several perceptual distortions which can perceive by a human being. The recently-proposed PW-SSIM metric incorporates the spatial information complexity to the SSIM metric. The HEVC encoding process maps some visual characteristics in order to avoid coding of redundant information. This paper comparatively evaluates the performance of the reference implementation of the HEVC and H.264 using the PW-SSIM metric, investigating its ability of mapping the aforementioned HEVC characteristic of incorporation of human vision heuristics. © 2015 The Authors.

Medeiros P.R.F.,University of Sao Paulo | Duarte S.N.,University of Sao Paulo | Uyeda C.A.,IFPB | Silva E.F.F.,Federal Rural University of Pernambuco | de Medeiros J.F.,UFERSA
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

In order to contribute to data available in the literature on tolerance of crops to soil salinity derived from fertilizer salts, the present study aims to determine the tolerance of tomato crop to the soil salinity, based on two managements of fertirrigation and six initial levels of salinity (1.0; 2.0; 3.0; 4.0; 5.0 and 6.0 dS m-1) from the variables production and components of production, in a protected environment with sandyclay soil. The experiment was conducted at the Department of Biosystems Engineering of ESALQ/USP, Piracicaba/SP. The experimental design was in randomized blocks, with 4 repetitions. Concluding that the production and the components of production of tomato crop were significantly affected both by the type of management of fertirrigation and by the levels of soil salinity, with a reduction in the tolerance of tomato crop, being classified as sensitive to soil salinity.

We evaluated vegetative and reproductive events of Ocotea pulchella (Nees) Mez (Lauraceae), Myrcia brasiliensis Kiaersk and Psidium cattleyanum Sabine (Myrtaceae) in a secondary semideciduous forest fragment for two years. We performed a circular data analysis and we correlated phenophases to temperature, daylenght and rainfall. Leaf fall and leaf appearance occurred continuously during the biennium featuring a low seasonality. The flowering, including the emergence of floral buds and anthesis, featured a seasonal pattern. Myrcia brasiliensis and Psidium cattleyanum showed great concentration of immature fruits around the average date (r), while fruit production of O. pulchella was almost constant (low r). The appearance of the fruits in P. cattleyanum and O. pulchella revealed a connection between daylenght and temperature in both years. All species had high concentration of individuals with mature fruits at some time of the year, allowing estimation of the average date of the reproductive event and indicating seasonality of maturation. The three species may potentially provide food resources for local animals, mainly birds, because mature fruits were available throughout the entire period.

Gomes S.M.S.,Federal University of Paraiba | De Lima V.A.,Federal University of Campina Grande | De Souza A.P.,Federal University of Paraiba | Do Nascimxento J.J.V.R.,IFPB | Do Nascimento E.S.,Federal University of Paraiba
Engenharia Agricola | Year: 2014

Plants respond to environmental adversities, becoming an indicator for assessing the environment quality. In this aspect, chlorophyll contents as well, carotenoids are used as a reliable indicator to associate environmental quality and pollution, mainly regarding the toxicity of heavy metals in higher plants. So, we aimed to evaluate the content of chlorophyll a, b, and total chlorophylls and carotenoids in plants vetiver [Vetiveria zizanioides (L.) Nash], maize (Zea mays L.) cv. AG 1051, sunflower (Helianthus annuus L.) cv. BRS 122/V-2000, and castor beans (Ricinus communis L.) cv. Northeastern BRS grown in contaminated soil with lead, with and without correction of soil pH, so they were used as indicators of metal stress by the soil. From the biochemical point of view, the correction of soil pH values caused chlorophyll a, b and total statistically higher for vetiver species and castor beans in the analyzed periods, except for the analysis performed 60 days after transplanting where only the species vetiver benefited from the correction of soil pH on the content of chlorophyll b and total. On the other hand plants without correction of soil pH showed a decrease of all chlorophyll levels. In addition, the largest increase in the synthesis of carotenoids, indicated that under stress the plants have developed alternative routes of dissipation of energy in order to avoid problems of photo-inhibition and photo-oxidation.

Sousa L.J.S.,Federal University of Ceará | Silva C.A.S.,IFPB | Almeida C.A.S.,Federal University of Ceará
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

Brane world six-dimensional scenario with string-like metric has been proposed to alleviate the problem of field localization. However, these models have been suffering from some drawbacks related with energy conditions as well as from difficulties to find analytical solutions. In this work, we propose a model where a brane is made of a scalar field with bounce-type configurations and embedded in a bulk with a string-like metric. This model produces a sound AdS scenario where none of the important physical quantities is infinite. Among these quantities are the components of the energy-momentum tensor, which have its positivity ensured by a suitable choice of the bounce configurations. Another advantage of this model is that the warp factor can be obtained analytically from the equations of motion for the scalar field, obtaining as a result a thick brane configuration, in a six-dimensional context. Moreover, the study of the scalar field localization in this scenario is done. © 2012 Elsevier B.V.

Meira F.A.,Federal University of Paraiba | Da Paz Medeiros Fernandes M.,IFPB | De Melo A.B.,Federal University of Paraiba | Da Silva E.P.,Federal University of Paraiba
Key Engineering Materials | Year: 2012

The use of EVA (Ethylene Vinyl Acetate) waste, from shoes industry, in the production of pre-molded block (EVA block) has been researched in the last 12 years. The results have shown great potential for these wastes to be used as lightweight aggregate, to replace natural aggregate in the manufacture of bricks made of cement based composites. This article examines the potentiality of waste EVA blocks recyclability, as aggregate in the production of new EVA blocks. In the experiment EVA blocks were molded in the mix proportion of 1:5 in volume (20% of sand and 80% of EVA) and determined the mass and compressive strength at 28 days. Then the EVA blocks were crushed and resulting aggregate was reused in part (portion retained on a 4.8 mm sieve) in the molding of new EVA blocks, using in dosages two different proportions of crushed aggregate (50% and 70%, EVAr - waste of crushed EVA blocks) in relation to the total volume of coarse aggregate of original EVA (EVA - waste from shoes industry). The average compressive strength at 28 days of the original EVA block was 1.2 MPa, whereas the block EVAr 70 was 2.2 MPa and the block EVAr 50 was 1.7 MPa. Thus, there was an 83% increase in the compressive strength on the block EVAr 70 and 44% on the block EVAr 50. It was also noticed there was no significant difference among the weights of all the blocks produced. So, it appears that the EVAr aggregate impacted more in the compressive strength than in the mass of the blocks. Thus, the recyclability of the EVA block appears viable. © (2012) Trans Tech Publications.

Melo J.,IFPB | Melo E.,Federal University of Rio Grande do Norte
Advances in Intelligent Systems and Computing | Year: 2015

This paper presents a preliminary discussion of the possibilities and limitations of Massive Open Online Courses (MOOC), a model of an online course whose contents are open and freely offered over the internet to anyone and anywhere. The main characteristic of this model is to allow an active engagement of tens or hundreds of thousands of students who self organize their own participation according to their goals, background, abilities and common interest. Advances in studies about Web Semantics and Adaptive Learning Systems are examples of research results in some of the various research areas of Computing in Education which are still incipient in MOOCs. © Springer International Publishing Switzerland 2015

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