Time filter
Source Type

De Souza G.R.,UFSJ | Stolfi J.,University of Campinas
AIP Conference Proceedings | Year: 2017

We describe efficient algorithms for adaptive multiscale approximation of functions that are sampled with uneven density and/or have important small-scale detail limited to small portions of their domain. Our algorithm constructs the approximation from the top down, using a special least squares fitting of the residual at each level, followed by a basis reduction procedure to discard elements that contribute very little to the approximation. An important feature of these algorithms is their generality, since they are independent of domain dimension and shape, mesh, and approximation basis. Another important feature is that they do not need to generate the full basis at each level. © 2017 Author(s).

Penchel R.A.,Federal Technological University of Paraná | Zang S.R.,UFSJ | Bergmann J.R.,Pontifical Catholic University of Rio de Janeiro | Moreira F.J.S.,Federal University of Minas Gerais
2017 11th European Conference on Antennas and Propagation, EUCAP 2017 | Year: 2017

This work presents a study of the electromagnetic performance of classical and shaped omnidirectional dual-reflector antennas in millimeter waves. An algorithms based on the concatenation of conic sections has been used to synthesize sub- and main-reflectors in order to provide a uniform phase and amplitude aperture distributions. The frequency analysis is focused on antenna radiation patterns across a 20% bandwidth, in order to establish band limits for omnidirectional dual-reflector antennas. The rigorous electromagnetic analysis was accomplished by a hybrid technique based on Mode Matching and Method of Moments. © 2017 Euraap.

Bruck L.R.,Fiat Group | Silveira M.E.,UFSJ
SAE Technical Papers | Year: 2014

To design a rear suspension of BAJA SAE vehicle it must be considered many parameters as robustness, vertical and lateral. This work shows a proposal to idealize a favorable lateral dynamic, with a big range of oveerster. This paper presents a double wishbone rear suspension, common used in this kind of vehicle, with a new toe controller system which target is to raise the oversteering characteristic. It was used multibody virtual analysis to simulate a real use of the vehicle. To better understand and measure the improvements of the system a method of understeering/oversteering gradient calculation was used. The results show that the OMA system induces the oversteer characteristic on the prototype which is very estimated on an off-road vehicle. Copyright © 2014 SAE International.

One of the major problems in tomato production is the frequent attack of pests. The use of wild tomato species made it possible to obtain pest resistant genotypes. Such resistance has been linked to the presence of allelochemicals called acylsugars, which are esters of fatty acids. The colorimetric method is normally used to quantify the levels of acylsugars, allowing an indirect selection of genotypes with high content of allelochemicals. This methodology has been used predominantly in the breeding programs of tomato to obtain pest-resistant genotypes. Despite the wide use of the colorimetric method for indirect selection of tomato genotypes with pest resistance, some steps of this methodology take great demand of time. Knowing the importance of the colorimetric method and, attempting to improve the efficiency and standardization of reading, we tried to evaluate new methodologies for quantifying the levels of acylsugars present in tomato leafets. Among the proposed methods, when using the spectrophotometer Multiskan FC with filter of 620 nm and doses of 100 μL per well (96 wells), we obtained results which were similar to the standard methodology. This methodological approach allowed for greater efficiency in the analysis, repeatability, greater standardization of results reducing the chance of errors during execution, besides the simultaneous analysis of many samples. Concluding, this method is feasible and effective and can be used to quantify acylsugars in tomato leafets with the purpose of indirect selection of resistant genotypes to pests.

Bandeira M.,Federal University of Säo João del Rei | da Silva M.A.,UFSJ | Camilo C.A.,UFSJ | Felicio C.M.F.,UFSJ.
Jornal Brasileiro de Psiquiatria | Year: 2011

objective: To evaluate family caregivers' satisfaction with mental health services and associated factors. Method: A cross-sectional correlational study of service evaluation was carried out with a sample of 85 family caregivers of psychiatric patients attending three public mental health services located in three towns in the state of Minas Gerais. Subjects were interviewed for the application of the Satisfaction with Mental Health Services Scale (SATIS-BR) and a sociodemographic and clinic variables questionnaire. Results: Results showed that most caregivers were satisfied or very satisfied with the services aspects evaluated. Family satisfaction was significantly and positively associated with patients' age and time spent without hospitalization. The statistical analysis did not detect any effect of type of service on family satisfaction. Conclusion: Patients' variables were the most important associated factors related to the family satisfaction. Family satisfaction was high, may be due partly to a comparison with other health services. Data suggest the need for more differentiation among services. Future studies with bigger and randomized samples will be able to reevaluate theses results.

Moreira I.C.,Federal University of Säo João del Rei | Bandeira M.,Federal University of Säo João del Rei | Pollo T.C.,Federal University of Säo João del Rei | Oliveira M.S.,UFSJ
Jornal Brasileiro de Psiquiatria | Year: 2014

objective: The purpose of this research was to make a cross-cultural adaptation of the Medication Adherence Rating Scale (MARS) for psychiatric patients to the Brazilian context. Methods: The procedure consisted of four phases: translation of the original scale, backtranslation, review by an Expert Committee and Pre-test study with a patients’ sample. results: The Expert Committee corrected the items’ translation when necessary and modifed the scale administration format and its instructions from self-report to face-to-face interview form in order to ensure easy understanding by the target population. During Pre-test, the instructions and most of the items were properly understood by patients, with the exception of three of them which had to be changed in order to ensure better understanding. The Pretest sample was composed by 30 psychiatric patients, with severe and persistent disorders mainly single (46.7%), female (60.0%), with a mean age of 43.8 years old and an average of five years of education. conclusion: The Brazilian version of MARS scale is now adapted to the Brazilian Portuguese language and culture and is easily understood by the psychiatric target population. It is necessary to do further research to evaluate the scale psychometric qualities of validity and reliability in order to use it in Brazil. © 2014, Editora Cientifica Nacional Ltda. All rights reserved.

dos Santos J.S.,Federal University of Campina Grande | de Lima V.L.A.,Federal University of Campina Grande | Borges Jr. J.C.F.,UFSJ | Silva L.V.B.D.,Federal University of Campina Grande | de Azevedo C.A.V.,Federal University of Campina Grande
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

With the objective of evaluating the parameters of transport retardation factor, dispersion-diffusion coefficient and effluent curves of the íons calcium, magnesium, sodium and potassium, present in domestic and swine raising wastewater, an experiment was conducted in laboratory with columns of Red Yellow Argisol and Regolithic Fluvisol. With the aid of flasks of Mariotte around two pore volumes of distilled water were passed in the columns; soon after, another flask was interconnected containing the wastewaters which leached 3.75 volume of pores divided in 25 aliqnot, totaling 600 samples. The obtained results lead to the conclussion that the retardation factors were higher for the sodium in the Red Yellow Argisol and for the magnesium in Regolithic Fluvisol leached with treated domestic wastewater. In reference to the swine raising wastewater, the largest values were calculated for the ion magnesium, in the two soils; as for the dispersion-diffusion coefficients, the highest values were observed for Regolithic Fluvisol, independent of the type of water.

Sarubbi J.F.M.,CEFETMG | De Vieira D.C.A.,CEFETMG | Wanner E.F.,CEFETMG | Silva C.M.,UFSJ
Proceedings of the NOMS 2016 - 2016 IEEE/IFIP Network Operations and Management Symposium | Year: 2016

In this work the allocation of Roadside Units (RSUs) in a V2I network is modeled as a Maximum Coverage Problem. The main objective is to maximize the number of distinct vehicles contacting the infrastructure. Two different approaches are presented to solve the problem. The first one is an ILP model that can found optimal solutions or give sharp upper and lower bounds for the problem. The second one is a GRASP-based heuristic that can found close-to-optimal solutions. The GRASP-based heuristic is compared with a previous work achieving better results. Furthermore, a new metric to measure the efficiency of a Deployment strategy is presented. © 2016 IEEE.

Stein J.,Federal University of Rio Grande do Sul | Nunes I.,Federal University of Rio Grande do Sul | Cirilo E.,UFSJ
ACM International Conference Proceeding Series | Year: 2014

Feature model configuration is known to be a hard, errorprone and time-consuming activity. This activity gets even more complicated when it involves multiple stakeholders in the configuration process. Research work has proposed approaches to aid multi-stakeholder feature model configuration, but they rely on systematic processes that constraint decisions of some of the stakeholders. In this paper, we propose a novel approach to improve the multi-stakeholder configuration process, considering stakeholders' preferences expressed through both hard and soft constraints. Based on such preferences, we recommend different product configurations using different strategies from the social choice theory. We conducted an empirical study to evaluate the effectiveness of our strategies with respect to individual stakeholder satisfaction and fairness among all stakeholders. Results indicate that particular strategies perform best with respect to these aspects. Copyright is held by the owner/author(s).

Araujo R.,UFSJ | Dias A.M.S.,Federal University of Rio Grande do Norte | Godoy G.C.D.,Federal University of Minas Gerais
Revista Materia | Year: 2013

The demand for components more resistant to wear and corrosion has promoted a growing interest in the surface engineering that develops processes to improve the tribological properties of materials. The use of ceramic coating has been an option used to improve the surface of mechanical properties. However, it is necessary to use tests to evaluate the mechanical behavior of the film and its interface with the substrate, which requires sophisticated equipment, skilled labor and consequently expensive cost. As computer systems have been improving recently, the use of numerical analysis to solve many technological problems has been increasingly frequent and current. Consequently, it allows its implementation with a low cost. This paper proposes to use the Finite Element Method (FEM) to simulate the indentation test with spherical indenters in conjugated compounds of metal substrate and ceramic film with different thicknesses, using commercial software. However, the use of this numerical technique to evaluate the indentation testing also has had problems in obtaining the mechanical properties of the conjugate. In this work, the numerical model also includes the effects of friction between the penetrator and the film to analyze the fields of stresses and strains along the different penetration depths.

Loading UFSJ collaborators
Loading UFSJ collaborators