2015
Autores
Pocas, I; Paco, TA; Paredes, P; Cunha, M; Pereira, LS;
Publicação
REMOTE SENSING
Abstract
A new procedure is proposed for estimating actual basal crop coefficients from vegetation indices (K-cb VI) considering a density coefficient (K-d) and a crop coefficient for bare soil. K-d is computed using the fraction of ground cover by vegetation (f(c VI)), which is also estimated from vegetation indices derived from remote sensing. A combined approach for estimating actual crop coefficients from vegetation indices (K-c VI) is also proposed by integrating the K-cb VI with the soil evaporation coefficient (K-e) derived from the soil water balance model SIMDualKc. Results for maize, barley and an olive orchard have shown that the approaches for estimating both f(c VI) and K-cb VI compared well with results obtained using the SIMDualKc model after calibration with ground observation data. For the crops studied, the correlation coefficients relative to comparing the actual K-cb VI and K-c VI with actual K-cb and K-c obtained with SIMDualKc were larger than 0.73 and 0.71, respectively. The corresponding regression coefficients were close to 1.0. The methodology herein presented and discussed allowed for obtaining information for the whole crop season, including periods when vegetation cover is incomplete, as the initial and development stages. Results show that the proposed methods are adequate for supporting irrigation management.
2015
Autores
Maia, C; Yomsi, PM; Nogueira, L; Pinho, LM;
Publicação
PROCEEDINGS IEEE/IFIP 13TH INTERNATIONAL CONFERENCE ON EMBEDDED AND UBIQUITOUS COMPUTING 2015
Abstract
This paper explores the behavior of parallel forkjoin tasks on multicore platforms by resorting to a semi-partitioned scheduling model. This model offers a promising framework to embedded systems which are subject to stringent timing constraints as it provides these systems with very interesting properties. The proposed approach consists of two stages-an offline stage and an online stage. During the offline stage, a multi-frame task model is adopted to perform the forkjoin task-to-core mapping so as to improve the schedulability and the performance of the system, and during the online stage, work-stealing is exploited among cores to improve the system responsiveness as well as to balance the execution workload. The objective of this work is twofold: (1) to provide an alternative technique that takes advantage of the semi-partitioned scheduling properties by offering the possibility to accommodate forkjoin tasks that cannot be scheduled in any pure partitioned environment, and (2) to reduce the migration overhead which has shown to be a traditional major source of non-determinism in global approaches. The simulation results show an improvement of the proposed approach over the state-of-the-art of up to 15% of the average response-time per task set.
2015
Autores
Silva, H; Bernardino, A; Silva, E;
Publicação
JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS
Abstract
We present a novel approach of Stereo Visual Odometry for vehicles equipped with calibrated stereo cameras. We combine a dense probabilistic 5D egomotion estimation method with a sparse keypoint based stereo approach to provide high quality estimates of vehicle's angular and linear velocities. To validate our approach, we perform two sets of experiments with a well known benchmarking dataset. First, we assess the quality of the raw velocity estimates in comparison to classical pose estimation algorithms. Second, we added to our method's instantaneous velocity estimates a Kalman Filter and compare its performance with a well known open source stereo Visual Odometry library. The presented results compare favorably with state-of-the-art approaches, mainly in the estimation of the angular velocities, where significant improvements are achieved.
2015
Autores
Vaz, CB; Alves, J; Mendes, I;
Publicação
Operations Research and Big Data: IO2015-XVII Congress of Portuguese Association of Operational Research (APDIO)
Abstract
This study purposes a Data Envelopment Analysis (DEA) framework to assess the performance of Non-Profit Organizations that look after children and young people. The DEA method is used to assess the managerial efficiency of eight institutions from Bragança district, since 2010 to 2013. The model evaluates each institution concerning the reduction of operational and staff costs incurred in providing social services to the number of users observed in each unit. A fair policy for the allocation of subsidies is designed according to the performance of institutions in order to support the regulator.
2015
Autores
Martins, H; de Sousa, JF;
Publicação
ICERI2015: 8TH INTERNATIONAL CONFERENCE OF EDUCATION, RESEARCH AND INNOVATION
Abstract
Education, like many institutions in contemporary society, faces significant challenges to the completion of its mission. This is especially true of higher education, which is often expected to be and seen as a facilitator of social and cultural advancement. Gamification is a relatively new concept intending to use elements from video games in non-game applications. Education is therefore an area with high potential for application of this concept since it seeks to promote people's motivation and engagement. The research in progress aims at creating a model for applying gamification in a course of Human Resources Management for Engineers, where testing and validating the results of that application can be possible. This paper presents the state of the art of gamification in higher education, as well as some guidelines and main features of a gamification framework to be applied in the course of a Masters in Engineering.
2015
Autores
Konadu D.D.; Mourão Z.S.; Allwood J.M.; Richards K.S.; Kopec G.M.; McMahon R.A.; Fenner R.A.;
Publicação
Global Environmental Change
Abstract
Energy system pathways which are projected to deliver minimum possible deployment cost, combined with low Greenhouse Gas (GHG) emissions, are usually considered as 'no-regrets' options. However, the question remains whether such energy pathways present 'no-regrets' when also considering the wider environmental resource impacts, in particular those on land and water resources. This paper aims to determine whether the energy pathways of the UK's Carbon Plan are environmental "no-regrets" options, defined in this study as simultaneously exhibiting low impact on land and water services resulting from resource appropriation for energy provision. This is accomplished by estimating the land area and water abstraction required by 2050 under the four pathways of the Carbon Plan with different scenarios for energy crop composition, yield, and power station locations. The outcomes are compared with defined limits for sustainable land appropriation and water abstraction.The results show that of the four Carbon Plan pathways, only the "Higher Renewables, more energy efficiency" pathway is an environmental "no-regrets" option, and that is only if deployment of power stations inland is limited. The study shows that policies for future low-carbon energy systems should be developed with awareness of wider environmental impacts. Failing to do this could lead to a setback in achieving GHG emission reductions goals, because of unforeseen additional competition between the energy sector and demand for land and water services in other sectors.
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