872 resultados para Hydrologic Modeling Catchment and Runoff Computations
Resumo:
There has been a significant increase in the skill and resolution of numerical weather prediction models (NWPs) in recent decades, extending the time scales of useful weather predictions. The land-surface models (LSMs) of NWPs are often employed in hydrological applications, which raises the question of how hydrologically representative LSMs really are. In this paper, precipitation (P), evaporation (E) and runoff (R) from the European Centre for Medium-Range Weather Forecasts (ECMWF) global models were evaluated against observational products. The forecasts differ substantially from observed data for key hydrological variables. In addition, imbalanced surface water budgets, mostly caused by data assimilation, were found on both global (P-E) and basin scales (P-E-R), with the latter being more important. Modeled surface fluxes should be used with care in hydrological applications and further improvement in LSMs in terms of process descriptions, resolution and estimation of uncertainties is needed to accurately describe the land-surface water budgets.
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This thesis consists of four manuscripts in the area of nonlinear time series econometrics on topics of testing, modeling and forecasting nonlinear common features. The aim of this thesis is to develop new econometric contributions for hypothesis testing and forecasting in these area. Both stationary and nonstationary time series are concerned. A definition of common features is proposed in an appropriate way to each class. Based on the definition, a vector nonlinear time series model with common features is set up for testing for common features. The proposed models are available for forecasting as well after being well specified. The first paper addresses a testing procedure on nonstationary time series. A class of nonlinear cointegration, smooth-transition (ST) cointegration, is examined. The ST cointegration nests the previously developed linear and threshold cointegration. An Ftypetest for examining the ST cointegration is derived when stationary transition variables are imposed rather than nonstationary variables. Later ones drive the test standard, while the former ones make the test nonstandard. This has important implications for empirical work. It is crucial to distinguish between the cases with stationary and nonstationary transition variables so that the correct test can be used. The second and the fourth papers develop testing approaches for stationary time series. In particular, the vector ST autoregressive (VSTAR) model is extended to allow for common nonlinear features (CNFs). These two papers propose a modeling procedure and derive tests for the presence of CNFs. Including model specification using the testing contributions above, the third paper considers forecasting with vector nonlinear time series models and extends the procedures available for univariate nonlinear models. The VSTAR model with CNFs and the ST cointegration model in the previous papers are exemplified in detail,and thereafter illustrated within two corresponding macroeconomic data sets.
Resumo:
o objetivo do presente trabalho é refletir e discutir através da construção de um paralelo histórico entre as arquiteturas física e organizacional, a possibilidade de aprendizado mútuo entre as duas arquiteturas. Desta forma, pretendemos verificar a relação direta entre as arquiteturas no que diz respeito à evolução do conhecimento humano e seus reflexos em ciências correlatas, bem como criar uma conexão funcional para o desenvolvimento de novos projetos, possibilitado pela lógica do pensamento desenvolvido ao longo desta pesquisa. Vamos observar ao longo deste trabalho que as arquiteturas não só têm muito a contribuir mutuamente na construção de novos projetos arquitetônicos adequados ao desenvolvimento das mais diversas atividades humanas, como também no implemento e análise de novas técnicas e metodologias de gestão, considerando-se a interação do conhecimento produzido pelas arquiteturas. Ainda no que diz respeito ao aprendizado, poderemos avaliar a situação atual do ensino da administração e da arquitetura, especificamente na possibilidade interdisciplinar das duas ciências, através de entrevistas com profissionais das respectivas áreas. Da mesma forma, a questão da utilização de novas tecnologias no âmbito das organizações, deverá ser analisada, objetivando identificar sua real utilidade, e consistência com um projeto sócio-político ideológico.
Resumo:
O presente estudo investigou o consumo público de eventos esportivos ao vivo dentro e fora do âmbito dos estádios. O objetivo principal do estudo foi determinar se o fã (torcedor), percebe uma relação de substituição ou de complementaridade entre as atitudes favoráveis ao comparecimento ao estádio ou a outros locais públicos para assistir a jogos de futebol. Adicionalmente, o estudo objetivou a investigação da influência da identificação do fã do esporte (torcedor) com seu time na atitude e consumo público do espetáculo do futebol no estádio ou em outros locais públicos; bem como se as características demográficas (gênero e faixa etária) exercem algum tipo de efeito moderador sobre as relações estudadas. Para abordar estes temas buscou-se referência na SIT – Social Identity Theory e na SCT – Self- Categorization Theory. Foi realizado um levantamento (survey), envolvendo torcedores dos 4 times cariocas de maior torcida, mediante entrevistas estruturadas assistidas. A amostra foi intencional e de conveniência e a coleta de dados totalizou 507 questionários válidos. A análise dos dados foi realizada em duas etapas. A primeira contemplando uma análise fatorial exploratória, que objetivou a observação preliminar da qualidade das escalas. A segunda etapa contemplou uma análise fatorial confirmatória com o objetivo de purificar as escalas. Foram avaliadas a confiabilidade e a validade convergente, discriminante e nomológica dos construtos. Para testar as hipóteses substantivas do estudo utilizou-se a técnica de modelagem de equações estruturais e a análise de multigrupos. Os resultados da análise permitiram suportar empiricamente três das cinco hipóteses substantivas. Os resultados sugerem que (a) A identificação do fã com o time exerce influência positiva sobre a atitude em relação a assistir a jogos no estádio; (b) A atitude favorável do torcedor em relação ao estádio exerce influência positiva sobre o comparecimento ao estádio; e (c) A atitude favorável do torcedor em relação a locais públicos exerce influência positiva sobre o comparecimento a locais públicos. Todavia, não foi possível suportar integralmente as hipóteses de que (d) A identificação do fã com o time exerce influência sobre a atitude em relação a locais públicos; e (e) A atitude do torcedor em relação ao estádio exerce influência sobre a atitude em relação a locais públicos. Também não foram suportados os efeitos de moderação do gênero e faixa etária.
Resumo:
In the teaching practice of architecture and urbanism in Brazil, educational legislation views modeling laboratories and workshops as an indispensable component of the infrastructure required for the good functioning of any architectural course of study. Although the development of information technology at the international level has created new possibilities for digital production of architectural models, research in this field being underway since the early 1990s, it is only from 2007 onwards that such technologies started to be incorporated into the teaching activity of architecture and urbanism in Brazil, through the pioneering experience at LAPAC/FEC/UNICAMP. It is therefore a recent experiment whose challenges can be highlighted through the following examples: (i) The implementation of digital prototyping laboratories in undergraduate courses of architecture and urbanism is still rare in Brazil; (ii) As a new developing field with few references and application to undergraduate programs, it is hard to define methodological procedures suitable for the pedagogical curricula already implemented or which have already been consolidated over the years; (iii) The new digital ways for producing tridimensional models are marked with specificities which make it difficult to fit them within the existing structures of model laboratories and workshops. Considering the above, the present thesis discusses the tridimensional model as a tool which may contribute to the development of students skills in perceiving, understanding and representing tridimensional space. Analysis is made of the relation between different forms of models and the teaching of architectural project, with emphasis on the design process. Starting from the conceptualization of the word model as it is used in architecture and urbanism, an attempt is made to identify types of tridimensional models used in the process of project conception, both through the traditional, manual way of model construction as well as through the digital ones. There is also an explanation on how new technologies for digital production of models through prototyping are being introduced in undergraduate academic programs of architecture and urbanism in Brazil, as well as a review of recent academic publications in this area. Based on the paradigm of reflective practice in teaching as designed by Schön (2000), the experiment applied in the research was undertaken in the integrated workshop courses of architectural project in the undergraduate program of architecture and urbanism at Universidade Federal do Rio Grande do Norte. Along the experiment, physical modeling, geometric modeling and digital prototyping are used in distinct moments of the design process with the purpose of observing the suitability of each model to the project s phases. The procedures used in the experiments are very close to the Action Research methodology in which the main purpose is the production of theoretical knowledge by improving the practice. The process was repeated during three consecutive semesters and reflection on the results which were achieved in each cycle helped enhancing the next one. As a result, a methodological procedure is proposed which consists of the definition of the Tridimensional Model as the integrating element for the contents studied in a specific academic period or semester. The teaching of Architectural Project as it is developed along the fifth academic period of the Architecture and Urbanism undergraduate program of UFRN is taken as a reference
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This work proposes an environment for programming programmable logic controllers applied to oil wells with BCP type method of artificially lifting. The environment will have an editor based in the diagram of sequential functions for programming of PLCs. This language was chosen due to the fact of being high-level and accepted by the international standard IEC 61131-3. The use of these control programs in real PLC will be possible with the use of an intermediate level of language based on XML specification PLCopen T6 XML. For the testing and validation of the control programs, an area should be available for viewing variables obtained through communication with a real PLC. Thus, the main contribution of this work is to develop a computational environment that allows: modeling, testing and validating the controls represented in SFC and applied in oil wells with BCP type method of artificially lifting
Resumo:
Due of industrial informatics several attempts have been done to develop notations and semantics, which are used for classifying and describing different kind of system behavior, particularly in the modeling phase. Such attempts provide the infrastructure to resolve some real problems of engineering and construct practical systems that aim at, mainly, to increase the productivity, quality, and security of the process. Despite the many studies that have attempted to develop friendly methods for industrial controller programming, they are still programmed by conventional trial-and-error methods and, in practice, there is little written documentation on these systems. The ideal solution would be to use a computational environment that allows industrial engineers to implement the system using high-level language and that follows international standards. Accordingly, this work proposes a methodology for plant and control modelling of the discrete event systems that include sequential, parallel and timed operations, using a formalism based on Statecharts, denominated Basic Statechart (BSC). The methodology also permits automatic procedures to validate and implement these systems. To validate our methodology, we presented two case studies with typical examples of the manufacturing sector. The first example shows a sequential control for a tagged machine, which is used to illustrated dependences between the devices of the plant. In the second example, we discuss more than one strategy for controlling a manufacturing cell. The model with no control has 72 states (distinct configurations) and, the model with sequential control generated 20 different states, but they only act in 8 distinct configurations. The model with parallel control generated 210 different states, but these 210 configurations act only in 26 distinct configurations, therefore, one strategy control less restrictive than previous. Lastly, we presented one example for highlight the modular characteristic of our methodology, which it is very important to maintenance of applications. In this example, the sensors for identifying pieces in the plant were removed. So, changes in the control model are needed to transmit the information of the input buffer sensor to the others positions of the cell
Resumo:
This paper describes the design, implementation and enforcement of a system for industrial process control based on fuzzy logic and developed using Java, with support for industrial communication protocol through the OPC (Ole for Process Control). Besides the java framework, the software is completely independent from other platforms. It provides friendly and functional tools for modeling, construction and editing of complex fuzzy inference systems, and uses these logical systems in control of a wide variety of industrial processes. The main requirements of the developed system should be flexibility, robustness, reliability and ease of expansion
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The objective of the dissertation was the realization of kinematic modeling of a robotic wheelchair using virtual chains, allowing the wheelchair modeling as a set of robotic manipulator arms forming a cooperative parallel kinematic chain. This document presents the development of a robotic wheelchair to transport people with special needs who overcomes obstacles like a street curb and barriers to accessibility in streets and avenues, including the study of assistive technology, parallel architecture, kinematics modeling, construction and assembly of the prototype robot with the completion of a checklist of problems and barriers to accessibility in several pathways, based on rules, ordinances and existing laws. As a result, simulations were performed on the chair in various states of operation to accomplish the task of going up and down stair with different measures, making the proportional control based on kinematics. To verify the simulated results we developed a prototype robotic wheelchair. This project was developed to provide a better quality of life for people with disabilities
Resumo:
The Pitimbu River Watershed (PRW), belonging to Potiguar capital metropolitan area, State of Rio Grande do Norte, contributes, among other purposes, to human using and animal watering. This watershed is extremely important because, besides filling up with freshwater approximately 30% of the south part of Natal (South, East and West Zones), contributes to the river shore ecosystem equilibrium. Face to the current conjuncture, this study aims to evaluate the urban development dynamics in the PRW, applying Cellular Automata as a modeling instrument, and to simulate future urban scenarios, between 2014 and 2033, using the simulation program SLEUTH. In the calibration phase, urban spots for 1 984, 1992, 2004 and 2013 years were used, with resolution from 100 meters. After the simulation, it was found a predominance of organic growth, expanding the BHRP from existing urban centers. The spontaneous growth occurred through the fullest extent of the watershed, however the probability of effective growth should not exceed 21%. It was observed that, there was a 68% increase for the period between 2014 and 2033, corresponding to an expansion area of 1,778 ha. For 2033, the source of Pitimbu River area and the Jiqui Lake surroundings will increase more than 78%. Finally, it was seen an exogenous urban growth tendency in the watershed (outside-in). As a result of this growth, hydraulics resources will become scarcer
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This paper discusses aspects related to the mathematical language and its understanding, in particular, by students of final years of elementary school. Accordingly, we aimed to develop a proposal for teaching, substantiated by mathematical modeling activities and reading, which takes advantage of the student of elementary school a better understanding of mathematical language for the content of proportion. We also aim to build / propose parameters for the assessment of reading proficiency of the language of the student in analyzing and modeling process, its ability to develop/improve/enhance this proficiency. For this purpose, we develop a qualitative research, with procedures for an action research whose analysis of the data is configured as Content Analysis. We refer to epistemological and didactic, in the studies: Piaget (1975, 1990), Vygotsky (1991, 2001), Bakhtin (2006), Freire (1974, 1994), Bicudo and Garnica (2006), Smole and Diniz (2001), Barbosa (2001), Burak (1992), Biembengut (2004), Bassanezi (2002), Carrasco (2006), Becker (2010), Zuin and Reyes (2010), among others. We understand that to acquire new knowledge one must learn to read and reading to learn it, this process is essential for the development of reading proficiency of a person. Modeling, in turn, is a process which enables contact with different forms of reading providing elements favorable to the development here mentioned. The evaluation parameters we use to analyze the level of reading proficiency of mathematical language proved to be effective and therefore a valuable tool that allows the teacher an efficient evaluation and whose results can guide you better in the planning and execution of their practice
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In this paper, the use of differential evolution ( DE), a global search technique inspired by evolutionary theory, to find the parameters that are required to achieve optimum dynamic response of parallel operation of inverters with no interconnection among the controllers is proposed. Basically, in order to reach such a goal, the system is modeled in a certain way that the slopes of P-omega and Q-V curves are the parameters to be tuned. Such parameters, when properly tuned, result in system's eigenvalues located in positions that assure the system's stability and oscillation-free dynamic response with minimum settling time. This paper describes the modeling approach and provides an overview of the motivation for the optimization and a description of the DE technique. Simulation and experimental results are also presented, and they show the viability of the proposed method.
Resumo:
The development of interactive systems involves several professionals and the integration between them normally uses common artifacts, such as models, that drive the development process. In the model-driven development approach, the interaction model is an artifact that includes the most of the aspects related to what and how the user can do while he/she interacting with the system. Furthermore, the interactive model may be used to identify usability problems at design time. Therefore, the central problematic addressed by this thesis is twofold. In the first place, the interaction modeling, in a perspective that helps the designer to explicit to developer, who will implement the interface, the aspcts related to the interaction process. In the second place, the anticipated identification of usability problems, that aims to reduce the application final costs. To achieve these goals, this work presents (i) the ALaDIM language, that aims to help the designer on the conception, representation and validation of his interactive message models; (ii) the ALaDIM editor, which was built using the EMF (Eclipse Modeling Framework) and its standardized technologies by OMG (Object Management Group); and (iii) the ALaDIM inspection method, which allows the anticipated identification of usability problems using ALaDIM models. ALaDIM language and editor were respectively specified and implemented using the OMG standards and they can be used in MDA (Model Driven Architecture) activities. Beyond that, we evaluated both ALaDIM language and editor using a CDN (Cognitive Dimensions of Notations) analysis. Finally, this work reports an experiment that validated the ALaDIM inspection method
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One new erythrinian alkaloid derivative, (+)-11 alpha-hydroxyerythravine (1), and the known (+)-erythravine (2) and (+)-alpha-hydroxyerysotrine (3) were isolated from the flowers of Erythrina mulungu. Their structures were determined by spectroscopic/spectrometric data interpretation of H-1, C-13, and 2D NMR and MS experiments. The relative configuration was established by NOESY analysis, while the conformation adopted by these molecules was evaluated through molecular modeling studies and coupling constants obtained by NMR analysis. Furthermore, the anxiolytic effects of the E. mulungu aqueous alcoholic crude extract and of the purified alkaloids were evaluated using the elevated T-maze test.