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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

VisualMet : um sistema para visualização e exploração de dados meteorológicos / VisualMet: a system for visualizing and exploring meteorological data

Manssour, Isabel Harb January 1996 (has links)
Os centros operacionais e de pesquisa em previsão numérica do tempo geralmente trabalham com uma grande quantidade de dados complexos multivariados, tendo que interpretá-los num curto espaço de tempo. Técnicas de visualização científica podem ser utilizadas para ajudar a entender o comportamento atmosférico. Este trabalho descreve a arquitetura e as facilidades apresentadas pelo sistema VisualMet, que foi implementado com base em um estudo das tarefas desenvolvidas pelos meteorologistas responsáveis pelo 8º Distrito de Meteorologia, em Porto Alegre. Este centro coleta dados meteorológicos três vezes ao dia, de 32 estações locais, e recebe dados similares do Instituto Nacional de Meteorologia, localizado em Brasília, e do National Meteorological Center, localizado nos Estados Unidos. Tais dados são resultados de observações de variáveis tais como temperatura, pressão, velocidade do vento e tipos de nuvens. As tarefas dos meteorologistas e as classes de dados foram observadas e analisadas para definir as características do sistema. A arquitetura e a implementação do VisualMet seguem, respectivamente, uma abordagem orientada a ferramentas e o paradigma de programação orientada a objetos. Dados obtidos das estações meteorológicas são instancias de uma classe chamada "Entidade". Três outras classes de objetos representando ferramentas que suportam as tarefas dos meteorologistas foram modeladas. Os objetos no sistema são apresentados ao usuário através de duas janelas, "Base de Entidades" e " Base de Ferramentas". A implementação da "Base de Ferramentas" inclui ferramentas de mapeamento (para produzir mapas de contorno, mapas de ícones e gráficos), ferramentas de armazenamento (para guardar e recuperar imagens geradas pelo sistema) e uma ferramenta de consulta (para ler valores de variáveis de estações selecionadas). E dada especial atenção a ferramenta de mapa de contorno, onde foi utilizado o método Multiquádrico para interpolação de dados. O trabalho apresenta ainda um estudo sobre métodos de interpolação de dados esparsos, antes de descrever detalhadamente os resultados obtidos com a ferramenta de mapa de contorno. Estes resultados (imagens) são discutidos e comparados com mapas gerados manualmente por meteorologistas do 8º Distrito de Meteorologia. Possíveis extensões do presente trabalho são também abordadas. / The weather forecast centers deal with a great volume of complex multivariate data, which usually have to be understood within short time. Scientific visualization techniques can be used to support both daily forecasting and meteorological research. This work reports the architecture and facilities of a system, named VisualMet, that was implemented based on a case study of the tasks accomplished by the meteorologists responsible for the 8th Meteorological District, in the South of Brazil. This center collects meteorological data three times a day from 32 local stations and receives similar data from both the National Institute of Meteorology, located in Brasilia, and National Meteorological Center, located in the United States of America. Such data result from observation of variables like temperature, pressure, wind velocity, and type of clouds. The tasks of meteorologists and the classes of application data were observed to define system requirements. The architecture and implementation of Visual- Met follow the tool-oriented approach and object-oriented paradigm, respectively. Data taken from meteorological stations are instances of a class named Entity. Three other classes of tools which support the meteorologists' tasks are modeled. Objects in the system are presented to the user through two windows, "Entities Base" and "Tools Base". Current implementation of the "Tools Base" contains mapping tools (to produce contour maps, icons maps and graphs), recording tools (to save and load images generated by the system) and a query tool (to read variables values of selected stations). The results of applying the multiquadric method to interpolate data for the construction of contour maps are also discussed. Before describing the results obtained with the multiquadric method, this work also presents a study on interpolation methods for scattered data. The results (images) obtained with the contour map tool are discussed and compared with the maps drawn by the meteorologists of the 8th Meteorological District. Possible extensions to this work are also presented.
12

Tocando (com) o lugar: os elementos meteorolÃgicos como forÃas criadoras no processo de composiÃÃo sonora e musical

Henrique Gomes 00 May 2018 (has links)
nÃo hà / O uso de diferentes mÃtodos de sonificaÃÃo de dados meteorolÃgicos e geofÃsicos à recorrente tanto em aplicaÃÃes cientÃficas quanto no contexto da criaÃÃo artÃstica. PropÃe-se, atravÃs de diferentes abordagens ao longo do processo de pesquisa, a criaÃÃo de uma sÃrie de sintetizadores e dispositivos sonoros sensÃveis à variaÃÃes de intensidade do vento, da luminosidade e da temperatura ambiente. Com o intuito de explorar as potencialidades do uso da sonificaÃÃo de dados de forÃas da natureza como mÃtodo de composiÃÃo sonora e musical, utilizam-se diversos sensores para controlar parÃmetros distintos do processo de sÃntese sonora digital. AtravÃs da experimentaÃÃo de circuitos e cÃdigos de programaÃÃo em Arduino, busca-se analisar os fatores que influenciam diferentes aspectos do processo de composiÃÃo junto aos fenÃmenos meteorolÃgicos. à apresentado o processo de desenvolvimento de trÃs sintetizadores que sÃo utilizados em diferentes ocasiÃes, alÃm da construÃÃo de uma mÃquina sonificadora e a produÃÃo de registros diversos do processo de elaboraÃÃo dos protÃtipos. Com base nas experimentaÃÃes realizadas, identificam-se aspectos pertinentes à atuaÃÃo de elementos da natureza como forÃas criativas durante o processo de composiÃÃo sonora e musical. / The use of different methods of sonification of meteorological and geophysical data is recurrent both in scientific applications and in the context of artistic creation. It is proposed, through different approaches throughout the research process, the creation of a series of synthesizers and sound devices sensitive to variations of wind intensity, luminosity and ambient temperature. In order to explore the potentialities of using sonification of forces of nature as a method of sound and musical composition, several sensors are used to control different parameters of the digital sound synthesis process. Through the experimentation of circuits and programming codes in Arduino, it is sought to analyze the factors that influence different aspects of the composition process with the meteorological elements. The process of development of three synthesizers that are used in different occasions is presented, along with the construction of a sonifying machine and the production of diverse material about the process of elaboration of the prototypes. Based on the experiments carried out, aspects pertinent to the performance of elements of nature as creative forces during the process of sound and musical composition are identified.
13

Three-Dimensional Hydrodynamic Modeling to Analyze Salinity Interaction of Coastal Marshland with a Lake: A Case Study of Mentor Marsh near Lake Erie, Ohio

Khadka, Pravakar 06 August 2020 (has links)
No description available.
14

Visualizing Process-Based Model Evaluation for Numerical Weather Prediction Models

Tjernström, Johanna January 2022 (has links)
The ability to predict the weather carries great societal benefit. To ascertain reliable predictions the numerical weather prediction models used need evaluation with particular attention paid to their representations of atmospheric processes. This type of process-based model evaluation is performed through comparison of large datasets of observational data and  model results. The Year Of Polar Prediction Project site Model Intercomparison Project (YOPPsiteMIP) works to further process-based model evaluation in polar regions and has, to this end, created extensive datasets for these types of analysis. However, the lack of standardized tools to visualize the analyses carries with it significant limitations for both the usability of the data as well as the standardization of the visualizations created from it. To amend this, a set of visualization tools have been created. They were evaluated in the context of visualization quality and source code maintainability. They were found satisfactory in all cases except for the runtime. These tools further the ability to perform process-based analysis with the YOPPsiteMIP datasets in standardized formats. They are limited to the project specific MDF file type. However, with the continued spread of the MDF file type the tools become increasingly useful in furthering model evaluation on larger scales than YOPPsiteMIP.
15

Evaluation of the AERMOD Model and Examination of Required Length of Meteorological Data for Computing Concentrations in Urban Areas

Masuraha, Anand 20 June 2006 (has links)
No description available.
16

Image Based Visualization Methods for Meteorological Data

Olsson, Björn January 2004 (has links)
Visualization is the process of constructing methods, which are able to synthesize interesting and informative images from data sets, to simplify the process of interpreting the data. In this thesis a new approach to construct meteorological visualization methods using neural network technology is described. The methods are trained with examples instead of explicitely designing the appearance of the visualization. This approach is exemplified using two applications. In the fist the problem to compute an image of the sky for dynamic weather, that is taking account of the current weather state, is addressed. It is a complicated problem to tie the appearance of the sky to a weather state. The method is trained with weather data sets and images of the sky to be able to synthesize a sky image for arbitrary weather conditions. The method has been trained with various kinds of weather and images data. The results show that this is a possible method to construct weather visaualizations, but more work remains in characterizing the weather state and further refinement is required before the full potential of the method can be explored. This approach would make it possible to synthesize sky images of dynamic weather using a fast and efficient empirical method. In the second application the problem of computing synthetic satellite images form numerical forecast data sets is addressed. In this case a mode is trained with preclassified satellite images and forecast data sets to be able to synthesize a satellite image representing arbitrary conditions. The resulting method makes it possible to visualize data sets from numerical weather simulations using synthetic satellite images, but could also be the basis for algorithms based on a preliminary cloud classification. / Report code: LiU-Tek-Lic-2004:66.
17

Concept and Workflow for 3D Visualization of Multifaceted Meteorological Data

Helbig, Carolin 10 August 2015 (has links) (PDF)
The analysis of heterogeneous, complex data sets has become important in many scientific domains. With the help of scientific visualization, researchers can be supported in exploring their research results. One domain, where researchers have to deal with spatio-temporal data from different sources including simulation, observation and time-independent data, is meteorology. In this thesis, a concept and workflow for the 3D visualization of meteorological data was developed in cooperation with domain experts. Three case studies have been conducted based on the developed concept. In addition, the concept has been enhanced based on the experiences gained from the case studies. In contrast to existing all-in-one software applications, the proposed workflow employs a combination of existing software applications and their extensions to make a variety of already implemented visualization algorithms available. The workflow provides methods for data integration and for abstraction of the data as well as for generating representations of the variables of interest. Solutions for visualizing sets of variables, comparing results of multiple simulation runs and results of simulations based on different models are presented. The concept includes the presentation of the visualization scenes in virtual reality environments for a more comprehensible display of multifaceted data. To enable the user to navigate within the scenes, some interaction functionality was provided to control time, camera, and display of objects. The proposed methods have been selected with respect to the requirements defined in cooperation with the domain experts and have been verified with user tests. The developed visualization methods are used to analyze and present recent research results as well as for educational purposes. As the proposed approach uses generally applicable concepts, it can also be applied for the analysis of scientific data from other disciplines. / In nahezu allen Wissenschaftsdisziplinen steigt der Umfang erhobener Daten. Diese sind oftmals heterogen und besitzen eine komplexe Struktur, was ihre Analyse zu einer Herausforderung macht. Die wissenschaftliche Visualisierung bietet hier Möglichkeiten, Wissenschaftler bei der Untersuchung ihrer Forschungsergebnisse zu unterstützen. Eine der Disziplinen, in denen räumlich-zeitliche Daten aus verschiedenen Quellen inklusive Simulations- und Observationsdaten eine Rolle spielen, ist die Meteorologie. In dieser Arbeit wurde in Zusammenarbeit mit Experten der Meteorologie ein Konzept und ein Workflow für die 3D-Visualisierung meteorologischer Daten entwickelt. Dabei wurden drei Fallstudien erarbeitet, die zum einen auf dem erstellten Konzept beruhen und zum anderen durch die während der Fallstudie gesammelten Erfahrungen das Konzept erweiterten. Der Workflow besteht aus einer Kombination existierender Software sowie Erweiterungen dieser. Damit wurden Funktionen zur Verfügung gestellt, die bei anderen Lösungsansätzen in diesem Bereich, die oft nur eine geringere Anzahl an Funktionalität bieten, nicht zur Verfügung stehen. Der Workflow beinhaltet Methoden zur Datenintegration sowie für die Abstraktion und Darstellung der Daten. Es wurden Lösungen für die Visualisierung einer Vielzahl an Variablen sowie zur vergleichenden Darstellung verschiedener Simulationsläufe und Simulationen verschiedener Modelle präsentiert. Die generierten Visualisierungsszenen wurden mit Hilfe von 3D-Geräten, beispielsweise eine Virtual-Reality-Umgebung, dargestellt. Die stereoskopische Projektion bietet dabei die Möglichkeit, diese komplexen Daten mit verbessertem räumlichem Eindruck darzustellen. Um dem Nutzer eine umfassende Analyse der Daten zu ermöglichen, wurden eine Reihe von Funktionen zur Interaktion zur Verfügung gestellt, um beispielsweise Zeit, Kamera und die Anzeige von 3D-Objekten zu steuern. Das Konzept und der Workflow wurden entsprechend der Anforderungen entwickelt, die zusammen mit Fachexperten definiert wurden. Des Weiteren wurden die Anwendungen in verschiedenen Entwicklungsstadien durch Nutzer getestet und deren Feedback in die Entwicklung einbezogen. Die Ergebnisse der Fallstudien wurden von den Wissenschaftlern benutzt, um ihre Daten zu analysieren, sowie diese zu präsentieren und in der Lehre einzusetzen. Da der vorgeschlagene Workflow allgemein anwendbare Konzepte beinhaltet, kann dieser auch für die Analyse wissenschaftlicher Daten anderer Disziplinen verwendet werden.
18

Estimativa da evapotranspiração de referência pelo Irrigâmetro nas condições climáticas do sul do Estado do Tocantins / Estimation of reference evapotranspiration by the Irrigameter in the climate conditions of the south of Tocantins state, Brazil

Giovanelli, Luan Brioschi 30 July 2012 (has links)
Made available in DSpace on 2015-03-26T13:23:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1512448 bytes, checksum: 7f7187b5bd2c3024f9b5d5a5182ec5d9 (MD5) Previous issue date: 2012-07-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / In the present issues related to world water scarcity, it becomes indispensable the search for alternatives that optimize the use of this resource for the purpose of irrigation, knowing that this activity takes up about 70% of the total world water extracted from aquifers, rivers and lakes. In this background, the methods for irrigation management are highlighted due to their importance in water preservation and maximization of the agricultural production, besides being essential to increase the performance and sustainability of the irrigation systems. Having mentioned this, the Irrigameter appears as an important alternative for irrigation management, because of its practicality and accuracy to estimate evapotranspiration, process which is used to determine the water requirement of the crops. Researches done with the Irrigameter in different weather conditions and in different seasons allow a better adjustment of the device in order to improve it. Therefore, the aims of this research were: (a) Determine the coefficient of the Irrigameter (KI) for each season, from September 2008 to September 2011, for different water levels inside the evaporator of the Irrigameter, in the south of Tocantins state - Brazil; (b) Establish, for each season, the water level in the evaporator referring to the KI of 1; and (c) Evaluate the effects of the meteorological elements (maximum temperature, minimum temperature, relative humidity, wind speed, and solar radiation) in the evapotranspiration estimated by the Irrigameter (ETI), which operates in different water levels inside the evaporator, for the seasons studied. The study was conducted in the experimental area of the Federal University of Tocantins (UFT), in the University Campus of Gurupi, situated in Gurupi, TO. The experiment was mounted in an entirely randomized delimitation, with seven water levels in the evaporator of the Irrigameter, representing the treatments, with three repetitions. The weather data were collected in an automatic weather station and used for determining the reference evapotranspiration (ET0), using the computer software REF-ET, based on the FAO 56 Penman-Monteith equation. There was a linear increase of the KI with the rising of the water level inside the evaporator in spring and summer. In the fall and in winter, the increase was exponential. The recommended water level in the evaporator, in a way that it estimates an ET0 in the south of Tocantins, for spring is equal to 3,4 cm; for the summer, 4,0 cm; for the fall, 3.8 cm; e for the winter, 2.3 cm. The meteorological elements relative humidity and solar radiation presented a high correlation with the ETl in all the seasons studied. The minimum temperature and wind speed were the meteorological elements with the lowest indirect effect on the ETl, when associated with the other elements. / Na atual problemática envolvendo a escassez de água no mundo, torna-se imprescindível a busca por alternativas que otimizem o uso desse recurso para fins de irrigação, haja vista que essa atividade consome cerca de 70% da água total mundial extraída de aquíferos, rios e lagos. Nesse contexto, os métodos de manejo da irrigação ganham destaque devido a sua importância quanto à conservação de água e maximização da produção agrícola, além de serem essenciais para melhorar o desempenho e a sustentabilidade de sistemas de irrigação. Diante do panorama mencionado, o Irrigâmetro surge como importante alternativa para manejo da irrigação, devido a sua praticidade e boa precisão para estimar a evapotranspiração, processo esse, utilizado para determinar a necessidade hídrica das culturas. Pesquisas realizadas com o Irrigâmetro, em diferentes condições climáticas e em diferentes períodos do ano, permitem realizar um melhor ajuste do aparelho, aperfeiçoando-o. Frente ao exposto, os objetivos desta pesquisa foram: (a) Determinar o coeficiente do Irrigâmetro (KI) para as estações do ano, no período de setembro de 2008 a setembro de 2011, para diferentes alturas da água dentro do evaporatório do Irrigâmetro, para a região sul do Estado do Tocantins; (b) Estabelecer, para cada estação, a altura da água no evaporatório referente ao KI igual a 1; e (c) Avaliar os efeitos dos elementos meteorológicos (temperatura máxima, temperatura mínima, umidade relativa do ar, velocidade do vento e radiação solar) na evapotranspiração estimada pelo Irrigâmetro (ETI), operando com diferentes alturas da água dentro do evaporatório, para as estações dos anos estudados. O estudo foi conduzido na área experimental da Universidade Federal de Tocantins (UFT), no Campus Universitário de Gurupi, situada no Município de Gurupi, TO. O experimento foi montado num delineamento inteiramente casualizado, com sete alturas da água no evaporatório do Irrigâmetro, representando os tratamentos, com três repetições. Os dados meteorológicos foram coletados numa estação meteorológica automática e utilizados na determinação da evapotranspiração de referência (ET0), com uso do programa computacional REF-ET, com base na equação de Penman-Monteith FAO 56. Ocorreu aumento linear do KI com a elevação da altura da água dentro do evaporatório nas estações da primavera e do verão. Já no outono e no inverno, o aumento foi exponencial. A altura da água recomendada no evaporatório do Irrigâmetro, de modo que este estime a ET0 na região Sul do Estado do Tocantins, para a estação da primavera, é igual a 3,4 cm; para o verão, 4,0 cm; para o outono, 3,8 cm; e, para o inverno, 2,3 cm. Os elementos meteorológicos umidade relativa e radiação solar apresentaram alta correlação com a ETI em todas as estações dos anos analisadas. A temperatura mínima e a velocidade do vento foram os elementos meteorológicos que apresentaram menor efeito indireto sobre a ETI, quando associadas aos demais elementos.
19

Návrh větrné elektrárny / Project of wind power station

Kuljovský, Martin January 2014 (has links)
This Master’s thesis concerns a theme of wind power in Czech Republic. It gives a brief overview of wind turbines available at the European market, in the observed performance of range 50 kW with subsequent economic analysis for the locality. At the same time, it mentioned a probability distribution and the mathematical models needed for processing and evaluation of meteorological data. Nevertheless, the main part of this work is focused on the aerodynamic design of the blade of wind power plant for given location and it’s both with and without considering the possible losses.
20

Letecká meteorologická data / Aviation meteorological data

Tarasovičová, Nikola January 2016 (has links)
This master thesis emphasizes the importance of aviation meteorological data for flight planning and for making inflight strategic decisions. It describes conventional ways of obtaining meteorological data before and during the flight. It provides the overview of alternative ways of acquiring weather related information. The master thesis compares how hazardous meteorological phenomena - thunderstorms, turbulence and icing - are displayed within the described commercial products.

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