Alternate treatments of jacobian singularities in polar coordinates within finite-difference schemes

Jacobian singularities of differential operators in curvilinear coordinates occur when the Jacobian determinant of the curvilinear-to-Cartesian mapping vanishes, thus leading to unbounded coefficients in partial differential equations. Within a finite-difference scheme, we treat the singularity at the pole of polar coordinates by setting up complementary equations. Such equations are obtained by either integral or smoothness conditions. They are assessed by application to analytically solvable steady-state heat-conduction problems.

Quantification of uncertainties associated with space-time estimates of short-term soil CO2 emissions in a sugar cane area

The characterization of soil CO2 emissions (FCO2) is important for the study of the global carbon cycle. This phenomenon presents great variability in space and time, a characteristic that makes attempts at modeling and forecasting FCO2 challenging. Although spatial estimates have been performed in several studies, the association of these estimates with the uncertainties inherent in the estimation procedures is not considered. This study aimed to evaluate the local, spatial, local-temporal and spatial-temporal uncertainties of short-term FCO2 after harvest period in a sugar cane area. The FCO2 was featured in a sampling grid of 60m×60m containing 127 points with minimum separation distances from 0.5 to 10m between points. The FCO2 was evaluated 7 times within a total period of 10 days. The variability of FCO2 was described by descriptive statistics and variogram modeling. To calculate the uncertainties, 300 realizations made by sequential Gaussian simulation were considered. Local uncertainties were evaluated using the probability values exceeding certain critical thresholds, while the spatial uncertainties considering the probability of regions with high probability values together exceed the adopted limits. Using the daily uncertainties, the local-spatial and spatial-temporal uncertainty (Ftemp) was obtained. The daily and mean emissions showed a variability structure that was described by spherical and Gaussian models. The differences between the daily maps were related to variations in the magnitude of FCO2, covering mean values ranging from 1.28±0.11μmolm-2s-1 (F197) to 1.82±0.07μmolm-2s-1 (F195). The Ftemp showed low spatial uncertainty coupled with high local uncertainty estimates. The average emission showed great spatial uncertainty of the simulated values. The evaluation of uncertainties associated with the knowledge of temporal and spatial variability is an important tool for understanding many phenomena over time, such as the quantification of greenhouse gases or the identification of areas with high crop productivity. © 2013 Elsevier B.V.

Avaliação de funções para modelagem do efeito da refratação ionosférica na propagação dos sinais GPS

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

Ensino e aprendizagem de estatística por meio da modelagem matemática: uma investigação com o ensino médio

Pós-graduação em Educação Matemática - IGCE

Técnicas de modelagem 3D aplicadas a dados paleobatimétricos das bacias de Santos e Campos e à simulação deformacional de objetos geológicos

Pós-graduação em Geologia Regional - IGCE

The economics of climate change

This paper focuses on several key economic issues relevant to climate change. Given the fact that changes in climate are projections using the best available data, it examines the economic principles of uncertainty and the precautionary approach, and then continues to address the key drivers of climate change. Climate change is expected to result in negative impacts and, in this regard, the consequences of anticipated rising temperatures and sea levels as well as changes in precipitation that may result in flooding and/or drought are addressed. However, the situation is not all negative and, as such, the opportunities that are likely to arise through adaptation and mitigation are discussed especially with respect to the Caribbean. In this regard and recognizing that it would be useful to Caribbean policymakers to utilize these opportunities and to address the negative impacts, the Economic Commission for Latin America and the Caribbean (ECLAC), through its subregional headquarters for the Caribbean, is spearheading a review of the economics of climate change in the Caribbean with a view to providing quantitative information to stakeholders in dealing with climate change. The paper makes recommendations for the Caribbean to address climate change at the national level. These include macroplanning; promotion of energy efficiency; creation of incentives to obtain support for implementation of alternative energy technologies; maintaining the will among stakeholders on a sustained basis for addressing climate change; and the conduct of relevant research into varieties of plants and animals that could adapt to changing climatic conditions. Finally, it must be recognized that to successfully combat climate change, the threats and opportunities must be properly assessed as part of an ongoing region-wide system of risk management, which should not be incidental, but integral, to national and regional planning and forecasting for the future.

Modelagem direta de dados de eletrorresistividade 3-D

Dentre os métodos geofísicos, o da Eletrorresistividade é um dos mais tradicionais, com o seu desenvolvimento ocorrido há mais de 80 anos. Durante esse tempo o seu uso acompanhou o avanço no poder de processamento numérico e mais recentemente, a modelagem e inversão tridimensional tornou-se uma possibilidade para o geofísico. Apresentamos, neste trabalho, a técnica de elementos finitos aplicada ao método da eletrorresistividade 3-D, através do cálculo do potencial secundário. Para o desenvolvimento da metodologia, simulamos o levantamento do método da eletrorresistividade 3-D com os arranjos Dipolo-Dipolo e Schlumberger, visando medir as variações laterais e verticais da resistividade aparente do solo. Estes arranjos consistem na injeção de corrente elétrica na superfície e de medidas de diferenças de potencial elétrico, resultante da interação da corrente elétrica com o solo. Sendo que, as fontes e receptores são localizados de acordo com os arranjos escolhidos para o levantamento. Neste trabalho, as curvas de sondagem e as pseudo-secções de resistividade aparente, são obtidas através da modelagem de eletrorresistividade 3-D, usando malha de elementos finitos regular. Para efeito de validação, os resultados são comparados com a resposta 3-D obtida a partir dos potenciais totais.

As copas do mundo de futebol de 1934 e 1938 por meio dos jornais de São Paulo e Rio de Janeiro

Pós-graduação em História - FCLAS

Modelagem fotogramétrica e calibração de um sistema de visão omnidirecional

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

Molecular design of new P3HT derivatives: Adjusting electronic energy levels for blends with PCBM

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

Missing transverse energy performance of the CMS detector

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Arranjo fisico na montagem com fluxo continuo nas superficies de comando composto

Based on the fierce competitiveness of manufacturing companies and the planning problems arising from the lack of flexibility and forecasting demand, companies are increasingly looking to reflect on the most appropriate methods to manage its manufacture. Today it is possible to obtain higher gains and lower costs through very efficient tools, this paper uses action-research to model and implement the physical layout of a manufacturing cell, with strong theoretical basement returned to Lean Production System and acting systematically in flexibility in mounting. Through observation and joint action of the observer and staff can report problems that occurred during the phases of planning and implementation of improvements. With the improvement of the physical arrangement in the assembly was possible to obtain significant gains by reducing the production cycle, the manpower required, spending of non-compliance and increasing productivity, final product quality and health in the workplace

Estudo da dinâmica climática e sua influência na qualidade da água de reservatórios urbanos

The present study sought to develop a methodology to analyze the water quality based on concepts and methods of climate and climatology respectively. In this way, it was tried to relate techniques and methodologies hydro and limno-meteorological with a rhythmic analysis technique developed within the Brazilian geographical climatology to assess and analyze the blooms of cyanobacteria, the main index of water quality found in reservoirs of “Alto Tietê” Basin and consequently the Metropolitan Region of São Paulo, an area of high environmental complexity due to its high degree of development and high population density. The meteorological data used to develop the study were collected from the meteorological station of the IAG / USP and the limnological data were collected from the Hydrological Monitoring System implemented by SABESP in Billings and Guarapiranga reservoirs as well as data laboratory of the same entity. The results obtained by the rhythmic and integrated analyze showed that the process of blooms of cyanobacteria is dependent not only on one specific factor, but a combination of meteorological factors that may disrupt the stability of reservoir and which can, during the stabilization process, provides the necessary conditions to the development of cyanobacteria. It was also shown by the results that the pace of Atlantic Polar Front Entrance during the winter in São Paulo, is a limiting factor to the growth of cyanobacteria due to their high frequency, keeping the reservoir balance throughout the period. Furthermore, another importance of this study is the possibility of prevention and forecasting periods which are inappropriate for the use of these reservoirs mainly for recreational activities

Previsão da demanda doméstica da aviação comercial européia

This paper work has as objective the study and forecasting of the demand behavior for the European commercial aviation industry. Once economy and demand has a straight relationship, the tool chosen to perform this forecast was the Econometry. In order to get a more efficient forecast, a complete analysis of the environment in which the aviation sector is, to understand all factors with influence over the market as a whole. Only then, the variables which would be tested for the correlation with the demand were picked. The final results of this study has achieved all objectives set and has given a better view over the European Commercial Aviation Market

Segmentation of Cell Nuclei Regions in Epithelium of Prostate Glands

This paper proposes a method for segmentation of cell nuclei regions in epithelium of prostate glands. This structure provides information to diagnosis and prognosis of prostate cancer. In the initial step, the contrast stretching technique was applied in image in order to improve the contrast between regions of interest and other regions. After, the global thresholding technique was applied and the value of threshold was defined empirically. Finally, the false positive regions were removed using the connected components technique. The performance of the proposed method was compared with the Otsu technique and statistical measures of accuracy were calculated based on reference images (gold standard). The result of the mean value of accuracy of proposed method was 93% ± 0.07.