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Mendes R.,Computacional CEFET | Wanner E.,CEFET | Martins F.,CEFET | Sarubbi J.,CEFET
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

Demand Responsive Transport (DRT) systems emanate as a substitute to face the problem of volatile, or even inconstant, demand, occurring in popular urban transport systems. This paper is focused in the Vehicle Routing Problem with Demand Responsive Transport (VRPDRT), a type of transport which enables passengers to be taken to their destination, as a shared service, trying to minimize the company costs and offer a quality service taking passengers on their needs. A manyobjective approach is applied in VRPDRT in which seven different objective functions are used. To solve the problem through traditional multiobjective algorithms, the work proposes the usage of cluster analysis to perform the dimensionaly reduction task. The seven functions are then aggregated resulting in a bi-objective formulation and the algorithms NSGA-II and SPEA 2 are used to solve the problem. The results show that the algorithms achieve statistically different results and NSGA-II reaches a greater number of non-dominated solutions when compared to SPEA 2. Furthermore, the results are compared to an approach proposed in literature that uses another way to reduce the dimensionality of the problem in a two-objective formulation and the cluster analysis procedure is proven to be a competitive methodology in that problem. It is possbile to say that the behavior of the algorithm is modified by the way the dimensionality reduction of the problem is made. © Springer International Publishing AG 2017.


Celani de Souza H.J.,São Paulo State University | Pontes F.J.,São Paulo State University | Duarte R.N.,CEFET | Sanches da Silva C.E.,Federal University of Itajubá | And 3 more authors.
Molecular and Cellular Probes | Year: 2011

Two mutations - Factor V Leiden (1691G > A) and the 20210G > A on the Prothrombin gene - are key risk factors for a frequent and potentially fatal disorder called Venous Thromboembolism. These molecular alterations can be investigated using real-time Polymerase Chain Reaction (PCR) with Fluorescence Resonance Energy Transfer (FRET) probes and distinct DNA pools for both factors. The objective of this paper is to present an application of Taguchi Experimental Design Method to determine the best parameters adjustment of a Molecular Assays Process in order to obtain the best diagnostic result for Venous Thromboembolism investigation. The complete process contains six three-level factors which usually demands 729 experiments to obtain the final result, if using a Full Factorial Array. In this research, a Taguchi L27 Orthogonal Array is chosen to optimize the analysis and reduce the number of experiments to 27 without degrading the final result accuracy. The application of this method can lessen the time and cost necessary to achieve the best operation condition for a required performance. The results is proven in practice and confirmed that the Taguchi method can really offer a good approach for clinical assay efficiency and effectiveness improvement even though the clinical diagnostics can be based on the use of qualitative techniques. © 2011 Elsevier Ltd.


Souza A.F.,IEEE EMBS | Coelli F.C.,CEFET
Pan American Health Care Exchanges, PAHCE 2011 - Conference, Workshops, and Exhibits. Cooperation / Linkages: An Independent Forum for Patient Care and Technology Support | Year: 2011

The equipment for magnetic resonance imaging (MRI) is the most reliable in the diagnosis area. System failures generate a series of problems: direct financial cost, delay in diagnosis of the patient, increased cost of maintenance contract, among others. This study examined the impact of infrastructure needed for the proper functioning of the MRI equipment availability. After a period of analysis, some suggestions were implemented able to reduce equipment downtime caused by failures in infrastructure. © 2011 IEEE.


Pedrosa M.W.,EPAMIG URECO | Mascarenhas M.H.T.,EPAMIG URECO | Freire F.M.,EPAMIG URECO | Viana M.C.M.,EPAMIG URECO | And 3 more authors.
Horticultura Brasileira | Year: 2012

An experiment was carried out at EPAMIG Centro Oeste, Prudente de Morais, Minas Gerais state, Brazil, from August 25 to December 2, 2008, to evaluate the effects of N rates on production and quality of hybrid squash cv. Tetsukabuto (Takaima F1). The treatments were five N rates (0, 37.5, 75, 150, 300 kg ha-1), as urea, split in four applications (30% at planting date, 20% at 20 days, 30% at 40 days and 20% at 60 days after emergence) in a randomized complete block design, with four replications. The N rates significantly affected the characteristics evaluated. The number of fruits increased from 2,498, reaching the fruit maximum number (6,794 ha-1) when applying 219 kg ha-1 N. The fruit yield was also influenced by N rates, the maximum yield (11.55 t ha-1) being achieved when 300 kg ha-1 of N were applied. The diameter and thickness of fruit pulp increased from 14.97 and 2.33 cm to achieve maximum points of 17.74 and 2.80 cm with N doses of 171 and 128 kg ha-1, respectively. The soluble solids content in the fruit pulp increased with increasing N doses and the content of 8°Brix was observed with the application of 300 kg ha-1 N. Fruit yield was also influenced by N rates being estimated 11.55 kg ha-1 as maximum yield with the application of 300 kg ha-1 N. The estimated dose of N on the maximum economic efficiency was obtained with the application of 262 kg ha-1, considering the prices of R$ 2.41 kg-1 of N and R$ 560.00 t-1 of hybrid squash fruits.


Ruas V.,CNRS Jean Le Rond d'Alembert Institute | Ruas V.,University of Sao Paulo | Brandao D.,CEFET | Brandao D.,Federal University of Fluminense | Kischinhevsky M.,Federal University of Fluminense
Journal of Computational Physics | Year: 2013

Two new Hermite finite elements are shown to be an advantageous alternative to well-known mixed methods in the simulation of diffusion processes in heterogeneous anisotropic media. Both are N-simplex based for N = 2 and N = 3 and provide flux continuity across inter-element boundaries. One of the methods denoted by P2H was introduced by the first author and collaborator for the case of homogeneous and isotropic media. Its extension to the case of heterogeneous and/or anisotropic cases is exploited here, keeping an implementation cost close to the popular Raviart-Thomas mixed finite element of the lowest order, known as RT0. The other method studied in detail in this work is a new Hermite version of the latter element denoted by RT0M. Formal results are given stating that, at least in the case of a constant diffusion, RT0M is significantly more accurate than RT0, although both elements have essentially the same implementation cost. A thorough comparative numerical study of the Hermite methods and RT0 is carried out in the framework of highly heterogeneous media among other cases. It turns out that both are globally superior all the way, and roughly equivalent to each other in most cases. © 2012 Elsevier Inc.


Petraglia M.R.,Federal University of Rio de Janeiro | Haddad D.B.,CEFET
Digital Signal Processing: A Review Journal | Year: 2012

In a context of supervised adaptive filtering, the sparsity of the impulse response to be identified can be employed to accelerate the convergence rate of the algorithm. This idea was first explored by the so-called proportionate NLMS (PNLMS) algorithm, where the adaptation step-sizes are made larger for the coefficients with larger magnitudes. Whereas fast initial adaptation convergence rate is obtained with the PNLMS algorithm for white-noise input, slow convergence is observed for colored input signals. The combination of the PNLMS approach and a subband structure results in an algorithm with better convergence rate for sparse systems and colored input signals. In this paper, the steady-state mean-square error (MSE) and the maximum value of the step-size β that allows convergence of the subband PNLMS-type algorithm are analyzed. Theoretical results are confirmed by simulations. © 2012 Elsevier Inc. All rights reserved.


Coelli F.C.,CEFET | Almeida R.M.V.R.,Federal University of Rio de Janeiro | Pereira W.C.A.,Federal University of Rio de Janeiro
Journal of Evaluation in Clinical Practice | Year: 2010

Objective This work develops a cost analysis estimation for a mammography clinic, taking into account resource utilization and equipment failure rates. Materials and methods Two standard clinic models were simulated, the first with one mammography equipment, two technicians and one doctor, and the second (based on an actually functioning clinic) with two equipments, three technicians and one doctor. Cost data and model parameters were obtained by direct measurements, literature reviews and other hospital data. A discrete-event simulation model was developed, in order to estimate the unit cost (total costs/number of examinations in a defined period) of mammography examinations at those clinics. The cost analysis considered simulated changes in resource utilization rates and in examination failure probabilities (failures on the image acquisition system). In addition, a sensitivity analysis was performed, taking into account changes in the probabilities of equipment failure types. Results For the two clinic configurations, the estimated mammography unit costs were, respectively, US$ 41.31 and US$ 53.46 in the absence of examination failures. As the examination failures increased up to 10% of total examinations, unit costs approached US$ 54.53 and US$ 53.95, respectively. The sensitivity analysis showed that type 3 (the most serious) failure increases had a very large impact on the patient attendance, up to the point of actually making attendance unfeasible. Conclusions Discrete-event simulation allowed for the definition of the more efficient clinic, contingent on the expected prevalence of resource utilization and equipment failures. © 2010 Blackwell Publishing Ltd.


Da Silva M.J.,Federal University of Ouro Preto | De Souza B.P.,Federal University of Ouro Preto | Mendes J.C.,Federal University of Ouro Preto | Brigolini G.J.S.,Federal University of Ouro Preto | And 2 more authors.
ACI Materials Journal | Year: 2016

Proposed herein is the use of steelmaking slag as aggregates (SSA) for precast concrete elements used as permeable paving blocks (pavers). For this study, SSA was subjected to segregation of metallic and nonmetallic fractions-the latter being used in the present work. The SSA had its particle size distribution adjusted. Subsequently, it was physically and chemically characterized. Five mixtures were designed: four with SSA and one with natural aggregates as a reference mixture. The pavers built were characterized physically (expansion, morphology, porosity, water absorption, void content, and absolute density); environmentally (leaching and dissolution); and mechanically (compression and flexural strength). As result, SSA pavers showed physical, mechanical, aesthetic, and environmental characteristics significantly similar to the conventional ones, indicating its technical and environmental feasibility. © 2016, American Concrete Institute. All rights reserved.


Stehling T.M.,CEFET | De Souza S.R.,CEFET | De Franca Filho M.F.,CEFET
GECCO 2015 - Companion Publication of the 2015 Genetic and Evolutionary Computation Conference | Year: 2015

This paper presents a hybrid Particle Swarm Optimization (PSO) for solving Vehicle Routing Problem with Time Windows (VRPTW). Three versions of the algorithm were implemented. The first version is a traditional PSO. In this case, the initialization is random and the best insertion for each customer on the route is evaluated. The second version is a combination of Greedy Randomized Adaptive Search Procedure (GRASP) and Push-Forward Insertion Heuristic (PFIH) with PSO. The last version, in addition to the previous characteristics, features a mutation operator after updating speed and position of each particle. For computational experiments, the 56 Solomon's instances are used and the results obtained in each version are compared with the best known results from literature. A statistical analysis indicates that the third version has a better performance than the other versions. Copyright is held by the owner/author(s).


de Sao Jose F.,Federal University of Ouro Preto | Imbelloni A.M.,CEFET | Nogueira F.C.,Federal University of Ouro Preto | Pereira C.A.,Federal University of Ouro Preto
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2016

Nickel ore dispersion before flotation using different reagents was investigated on a bench scale to improve metallurgical recovery and selectivity. The nickel ore had a content of 0.8 pct nickel and 14.5 pct MgO. A positive linear correlation between MgO and Ni was found. Carboxy methyl cellulose, both pure and combined with Na2CO3, was the best dispersant used. The most efficient collector was potassium amyl xanthate combined with mercaptobenzothiazole, and the addition of xanthate was decisive for this good result because it is normally more stable in the pH range used in the tests. A pH change from 7 to 9 resulted in a metal recovery increase of 49.3 pct, together with an increase of 6.25 pct of MgO in the concentrate. © 2016, The Minerals, Metals & Materials Society and ASM International.

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