2017
Autores
de Souza e Silva, RDDE; de Oliveira, RC; de Lima Tostes, MED;
Publicação
ENERGIES
Abstract
In this paper, a methodology was developed to analyze the results of energy efficiency programs used in the electricity distribution sector in Brazil. Analyzing the gains obtained through the investments made, and classifying which actions resulted in the best performance, contributed to decision making on the best allocation of investments to obtain the greatest energy savings. The Brazilian Energy Efficiency program was analyzed with a developed non-parametric model, using the data envelopment analysis method, and the categories of projects with better performance were determined. A database of the results from 1704 projects, from 2008 to 2016 in the Energy Efficiency program in Brazil's electricity distribution sector, was used. The results obtained show that the best performance was achieved by projects in the industrial and cogeneration categories; however, in Brazil these constitute only 4.24% of the projects presented and 5.28% of the total investments in the last eight years, indicating a need to review the regulatory strategies for energy efficiency in this country.
2017
Autores
Bispo, J; Cardoso, JMP;
Publicação
SOFTWARE-PRACTICE & EXPERIENCE
Abstract
This paper describes MATISSE, a compiler able to translate a MATLAB subset to C targeting embedded systems. MATISSE uses LARA, an aspect-oriented programming language, to specify additional information and transformations to the input MATLAB code, for example, insertion of code for initialization of variables, and specification of types and shapes of variables. The compiler is being developed bearing in mind flexibility, multitarget and multitoolchain support, allowing for the generation of several implementations in C from the same reference code in MATLAB. In this paper, we also present a number of techniques being employed in MATLAB to C compilation, such as element-wise mapping operations, matrix views, weak types, and intrinsics. We validate these techniques using MATISSE and a set of representative benchmarks. More specifically, we evaluate the compiler with a set of 31 benchmarks using an embedded system board and a desktop computer. The results show speedups up to 1.8x by employing information provided by LARA aspects, when compared with C code generated without additional user information. When compared with the execution time of the original code running on MATLAB, the execution time of the generated C code achieved a geometric mean speedup of 13x. Copyright (c) 2016 John Wiley & Sons, Ltd.
2017
Autores
Bleier, M; Dias, A; Ferreira, A; Pidgeon, J; Almeida, J; Silva, E; Schilling, K; Nuechter, A;
Publicação
IFAC PAPERSONLINE
Abstract
The planning of mining operations in water filled open-pit mines requires detailed bathymetry to create a mine plan and assess the involved risks. This paper presents post processing techniques for creating an improved 3D model from a survey carried out using an autonomous surface vehicle with a multibeam sonar and a GPS/INS navigation system. Inconsistencies of the created point cloud as a result of calibration errors or GPS signal loss are corrected using a continuous-time simultaneous localization and mapping (SLAM) solution. Signed distance function (SDF) based mapping is employed to fuse the measurements from multiple runs into a consistent representation and reduce sensor noise. From the signed distance function model we reconstruct a 3D surface mesh. We use this terrain model to establish a virtual reality scene for immersive data visualization of the mining operations for testing and planing during development. Results of the proposed approach are demonstrated on a dataset captured in an abandoned submerged inland mine.
2017
Autores
de Armas, J; Juan, AA; Marques, JM; Pedroso, JP;
Publicação
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
Abstract
The uncapacitated facility location problem (UFLP) is a popular combinatorial optimization problem with practical applications in different areas, from logistics to telecommunication networks. While most of the existing work in the literature focuses on minimizing total cost for the deterministic version of the problem, some degree of uncertainty (e.g., in the customers' demands or in the service costs) should be expected in real-life applications. Accordingly, this paper proposes a simheuristic algorithm for solving the stochastic UFLP (SUFLP), where optimization goals other than the minimum expected cost can be considered. The development of this simheuristic is structured in three stages: (i) first, an extremely fast savings-based heuristic is introduced; (ii) next, the heuristic is integrated into a metaheuristic framework, and the resulting algorithm is tested against the optimal values for the UFLP; and (iii) finally, the algorithm is extended by integrating it with simulation techniques, and the resulting simheuristic is employed to solve the SUFLP. Some numerical experiments contribute to illustrate the potential uses of each of these solving methods, depending on the version of the problem (deterministic or stochastic) as well as on whether or not a real-time solution is required.
2017
Autores
Lujano Rojas, JM; Dufo Lopez, R; Bernal Agustin, JL; Dominguez Navarro, JA; Osorio, GJ; Catalao, JPS;
Publicação
2017 IEEE MANCHESTER POWERTECH
Abstract
Environmental pollution and greenhouse gas emissions, as well as oil depletion are prime motivators for the development and adoption of renewable power sources. However, the traditional operating philosophy of power systems and the random nature of these sources represent an important barrier for their massive deployment. Fluctuations of wind and solar power generation integrated as distributed sources can induce important variations on the voltage profile, leading to values out of the range typically suggested by power quality standards. To deal with this problem, in this paper the optimal setting of voltage regulators (VRs) at each hour has been optimally determined by implementing a genetic algorithm with integer codification, so that it can be effectively integrated with the load flow methodologies currently available in the literature without requiring any linearization process. Results obtained from the analysis of a case study reveal the behavior of the optimal VR settings and reactive power compensation on a daily basis, which are highly correlated with the daily load profile.
2017
Autores
Goncalves, J; Costa, P;
Publicação
2017 25TH MEDITERRANEAN CONFERENCE ON CONTROL AND AUTOMATION (MED)
Abstract
In this paper it is presented a low cost experiment based on a small Arduino based prototype. The chosen educational challenge is a classical introductory experiment, that consists in following a line with a mobile robot. The presented experiment has as goal to introduce students to mobile robotics, having as base a challenge and a kinematics that are commonly applied in Junior competitions. A group of students participated in a workshop that consisted, initially, in a lecture where tutors explained the differential robot kinematics and how to develop a controller for the proposed challenge. Then the students, after the theoretical introduction, implemented the proposed robot controller.
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