913 resultados para Séries Temporais


Relevância:

60.00% 60.00%

Publicador:

Resumo:

In different regions of Brazil, population growth and economic development can degrade water quality, compromising watershed health and human supply. Because of its ability to combine spatial and temporal data in the same environment and to create water resources management (WRM) models, the Geographical Information System (GIS) is a powerful tool for managing water resources, preventing floods and estimating water supply. This paper discusses the integration between GIS and hydrological models and presents a case study relating to the upper section of the Paraíba do Sul Basin (Sao Paulo State portion), situated in the Southeast of Brazil. The case study presented in this paper has a database suitable for the basin's dimensions, including digitized topographic maps at a 50,000 scale. From an ArcGIS®/ArcHydro Framework Data Model, a geometric network was created to produce different raster products. This first grid derived from the digital elevation model grid (DEM) is the flow direction map followed by flow accumulation, stream and catchment maps. The next steps in this research are to include the different multipurpose reservoirs situated along the Paraíba do Sul River and to incorporate rainfall time series data in ArcHydro to build a hydrologic data model within a GIS environment in order to produce a comprehensive spatial-temporal model.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This work was based on a complete tree stem analysis to assess the growth behavior and current annual volume increment (CAI) of four individuals of Pinus taeda sampled in populations located in the 'Avare II' State Forest and 'Itapeva' Experimental Station, State of São Paulo. The relationship between the rainfall time series and CAI index was examined by means of cross-correlation coefficients. The convergence coefficients (GL) between the series were calculated. In the individuals that showed a statistical significance in the cross-correlation between the time series, the previous year's rainfall significantly affected the current annual volume increment in the year under consideration. The GL values between the series were higher in 'Itapeva'. Since the two sites showed no significant difference in rainfall distribution, the difference was attributed to the soil texture at 40-60 cm - medium in 'Avare' and clayey in 'Itapeva', so the CAI of the 'Itapeva' plantation reflects the higher availability of water.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

In this work, some aspects of the erythrocyte cycle of the malaria parasite was incorporated into a cellular automata model to simulated the major factors leading to disruption of the erythrocyte cycle and consequent appearance of gametocytes, which infected the mosquitoes. Furthermore, the time seies of parasitaemia of infected patients was analyzed and compared to simulated data. The results suggested that differences in the temporal patterns of the asexual parasitaemia are associated with different effectiveness of the immune system in controlling the infection

Relevância:

60.00% 60.00%

Publicador:

Resumo:

O presente trabalho apresenta em sua essência conceitos relacionados as práticas de Governança Corporativa no mundo e, principalmente, no Brasil. Tais práticas são leis que ajudam na Bolsa de Valores, trazendo mais transparência e confiança para os agentes e está desenvolvido no segundo capítulo. Tais práticas, então, afetarão diretamente as expectativas dos agentes a investirem seus capitais de forma mais segura. Para tanto, é necessário ter uma ideia geral de como são afetadas tais expectativas e é onde está desenvolvido o primeiro capítulo. Para concluir, é feita uma análise empírica, baseada em séries temporais, de econometria para auxiliar se o que a teoria nos diz é comprovada na prática e são usadas como base os Bancos Nossa Caixa e Banco Bradesco

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The objective of this study was to test the validity of the real exchange rate in the long run. For that five tests were performed based on equation, which relates to real exchange rate, international trade, domestic income. The main difference is that the tests when we are working with quarterly data, the parameters are significantly different from zero – i.e., the variables real exchange rate, international trade, domestic income and net exports on long term relationship – and, moreover, the signs are as expected. This implies that it is possible to increase exports with currency devaluation. Thus, based on data and tests that work we conclude that the exchange rate is an important instrument of trade policy, given that devaluations are valid even in the long term.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The objective of this paper is to verify and analyze the existence in Brazil of stylized facts observed in financial time series: volatility clustering, probability distributions with fat tails, the presence of long run memory in absolute return time series, absence of linear return autocorrelation, gain/loss asymmetry, aggregative gaussianity, slow absolute return autocorrelation decay, trading volume/volatility correlation and leverage effect. We analyzed intraday prices for 10 stocks traded at the BM&FBovespa, responsible for 52.1% of the Ibovespa portfolio on Sept. 01, 2009. The data analysis confirms the stylized facts, whose behavior is consistent with what is observed in international markets.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Time series tendencies are an important tool for different sectors such as the scientific community, industries and environmental protection agencies who can evaluate the variability of a specific parameter in time, what is very important piece of information for establishing corrective and preventive actions. This work presents a time series model of main physical, chemical and biological parameters of the Water Quality Index (WQI) determined for different selected points of a hydrographical basin form May/2006 to Aug/2010. The statistical model Arima enabled a better understanding of the physical, chemical and biological processes that most clearly influences WQI. The Arima model allowed the assessment of the trend of several parameters used in the calculation of the WQI, showing that dissolved oxygen, turbidity, total nitrogen, and fecal E. coli were highly correlated and are the parameters that caused the index changes over time.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)