São Paulo Federal Institute of Education, Science and Technology

About: São Paulo Federal Institute of Education, Science and Technology is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1707 authors who have published 2374 publications receiving 11333 citations.

An inexpensive anemometer using arduino board

Abstract: In all studies involving wind speed, such as meteorology, wind turbines and agriculture accurate speed information for decision making is required. There are several types of anemometers, with medium and high costs, such as cup, hot wire and pitot tubes, the hot wire being more sensitive and expensive than others. The device developed in this work is the cup anemometer, that is easy to build. The great advantage of this device is the low cost, with an approximate value of US$ 50.00, using simple materials that are easy to find in commercial stores. The Reed Switch sensor is also another advantage as it does not require a sophisticated programming, as well as the open platform Arduino. The use of theoretical aerodynamic drag coefficients and the presented calculations resulted in values very close to a commercial anemometer. The coefficient of determination between the cup Anemometer and the standard sensor of Meteorological Research Institute IPMet/Brazil is R 2 =0.9999, indicating strong correlation between the instruments. As the reference anemometer (IPMet) has high embedded technology and the prototype is low cost, we conclude that the project has an attractive cost benefit for possible development and production, reaching the objective of this work.

Less conservative state feedback design conditions for switched Takagi-Sugeno fuzzy systems

Abstract: Relaxed conditions for switched Takagi-Sugeno fuzzy systems under state feedback are proposed. The result explores two strategies to decrease the linear matrix inequalities (LMIs) conservatism. Properties of membership are explored to add slack matrix variables into the LMI formulation and a standard right hand side LMI relaxation procedure is extended for switched TS fuzzy systems. Numerical examples illustrate the efficiency of the presented results.

The center pivot irrigation in minas gerais state, brazil, under the optics of google earth

Abstract: The center pivot irrigation in Minas Gerais state, Brazil, under the optics of Google Earth EDUARDO PINHEIRO DE FREITAS1 AND WAGNER ALVES DE ANDRADE2 1 IFSP campus Barretos, Barretos – SP, Brazil. E-mail: eduardo.freitas@ifsp.edu.br2 UCS, Caxias do Sul - RS, Brazil. E-mail: vaguinho.a@hotmail.com 1 Abstract The Southeast region has the highest water demand and the largest irrigated area in Brazil, with emphasis on the central pivots in the state of Minas Gerais. However, the reliability of this information is poor, which limits its use to such management. As an alternative to obtain more consistent data, especially regarding central pivots, there is the use of remote sensing with satellite images to the mapping of irrigated areas in spatial and temporal scales, with some technical and financial difficulties as barriers. Google Earth solves part of these barriers, but the temporal discontinuity is a point to be evaluated. In this context, this work aimed to use Google Earth to visually identify areas irrigated by center pivot in Minas Gerais, from an overflight in the state at an altitude of the viewpoint of 4,000 meters, characterize and register them, which resulted in 4,607 areas totaling 295,059.76 ha, with the municipality of Paracatu presenting the largest number with 598 areas, and Unai, the greatest extent, with 42,846.04 ha. Data available in the literature of 2010 indicated 4,432 areas occupying 303,368 ha with 570 areas in Paracatu and 44,258 ha in Unai, confirming the functionality of the method. Keywords: GIS, water resources, remote sensing. FREITAS, E. P. DE; ANDRADE, w. a. DE A irrigacao por pivo central no estado de Minas Gerais, Brasil, sob a optica do Google Earth 2 Resumo A regiao Sudeste tem a maior demanda de agua no Brasil e a maior extensao irrigada, com destaque para os pivos centrais no estado de Minas Gerais, contudo, a confiabilidade destas informacoes e precaria e limitam seu uso para a referida gestao. Como opcao a obtencao de dados mais consistentes, principalmente quanto aos pivos centrais, tem-se a utilizacao do sensoriamento remoto com imagens de satelites para o mapeamento em escalas espacial e temporal, tendo como entraves algumas dificuldades tecnicas e financeiras. O Google Earth soluciona parte destes entraves, tendo na descontinuidade temporal um dos pontos a ser avaliado. Neste contexto, o presente trabalho teve como objetivo utilizar o Google Earth para identificar visualmente areas irrigadas por pivo central em Minas Gerais, a partir de um sobrevoo no estado a uma altitude do ponto de visao de 4000 metros, caracteriza-las e cadastra-las, o que resultou em 4607 areas que totalizaram 295059,76 ha, com o municipio de Paracatu apresentando o maior numero, com 598 areas, e Unai a maior extensao, com 42846,04 ha. Dados disponiveis do ano de 2010 indicam 4432 areas ocupando 303368 ha, com 570 areas em Paracatu e 44258 ha em Unai, ratificando a funcionalidade do metodo. Palavras-chave: SIG, recursos hidricos, sensoriamento remoto.

Management and Equalization of Energy Storage Devices for DC Microgrids Using a SoC-Sharing Function

Abstract: This paper presents a method for Energy Storage Systems (ESSs) equalization and energy management in dc microgrids (MGs) with slow dynamic sources, such as Fuel Cells (FCs). The three main features of this method are the ESSs equalization, the energy management between the ESSs and the FC, and the ability to suppress fast transients of load, preventing damages in the FC. The equalization is performed using a State of Charge ( $SoC$ )-Sharing Function, which is based on a Sigmoid Function (SF). The $SoC$ -Sharing Function is designed similarly to the droop controller, therefore, it is suitable for operation in droop based MGs. Additionally, the ability to suppress fast transients of load is performed by adding a low pass filter in the FC control loop. The main advantages of this method are the SF smooth behavior and the lack of need for a high-speed link of communication between the sources. To evaluate the MG stability, the Lyapunov’s Indirect Method is applied in the MG model considering different scenarios varying the $SoC$ and load connected to the dc-link. Finally, the model is validated by comparing simulation and experimental results supplied by a lab-scale prototype.