"Winds aloft are normally determined from the horizontal projection of an ascending balloon's path on a polar diagram. This method obtains a value for the average wind speed and direction for the layer through which the balloon has ascended during a two-minute interval by drawing a straight line between the horizontal projection of the balloon's position at the beginning and end of the two-minute interval. The horizontal projection of a balloon's actual path is a smooth curve and it is believed that a more accurate measurement of the average wind speed and direction for the layer will be obtained by determining the wind speed from the length of the curve for the two-minute interval and determining the direction from the tangent to the balloon's position along the curve at the intermediate time interval. The wind speed was computed by both methods for three months' data and the results compared with the purpose of determining a correction factor. The wind direction as determined by the method suggested was found not to vary appreciably from the direction determined by the conventional method. It was found that there is often a considerable difference in the wind speed as determined by the two methods especially at very low wind speeds, with the wind speed determined by the conventional method always being too small, but that it is impractical to apply a correction factor to reported winds when one considers the absolute value, rather than the percentual value, of the difference"--Abstract. / Typescript. / "August, 1956." / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Science." / Includes bibliographical references (leaf 16).

published_or_final_version / abstract / toc / Statistics / Master / Master of Philosophy

This thesis represents the first large-scale, systematic study to use the double trace moment (DTM) technique in order to characterize the universal multifractal nature of aircraft-based measurements of wind velocity and several passive scalar concentrations under a variety of ambient conditions. Power-law scaling behaviour was demonstrated for the examined fields, from the smallest accessible measurement scales up to at least 250 km, right through the "mesoscale gap" postulated by the standard model of atmospheric dynamics. DTM results indicate remarkable stability in the estimates of the multifractality index, $ alpha$, and the codimension of mean singularity, $C sb1$, for wind velocity measured under different conditions of surface type, time of year, and measurement height within the surface boundary layer. Estimates for $ rm CO sb2, H sb2O, and O sb3$ were largely dominated by the wind velocity statistics as expected, but slightly sensitive to measurement height and moderately sensitive to significant changes in the underlying surface. Results showed that all of the fields examined may be classified as "unconditionally hard" multifractals, which is consistent with previously-published results for ground-based wind velocity measurements. It was demonstrated using probability distribution and multifractal analyses that ensemble statistical moments above approximately second-order can be expected to diverge for all examined fields due to the extremely singular nature of the fields at sub-resolution scales, and that the currently-employed quasi-local aircraft based sampling strategy is capable of reliably characterizing the statistical behaviour of the examined fields up to this physically-imposed limit. (Abstract shortened by UMI.)

No description available.

High frequency turbulent temperature measurements were performed above clipped grass in the lower atmospheric surface layer in conjunction with three-dimensional turbulent velocities. Measurements were also made of turbulent temperature inside a corn canopy and at the canopy top. The 500Hz temperature time series were collected over periods of varying intervals, to a maximum of 24 hours. / The multifractal analysis was performed on several datasets. First scaling properties of the temperature and the velocity fields were examined. Our results suggest that scaling is not observed throughout the entire range but on different regimes. The physically related regimes corresponding to the clipped grass experiment include the inertial subrange, the trend for diurnal peak, and a range between them, all together featuring the existence of the hourly gap. In the canopy experiment, except for the above feature, the effects of the presence of plant objects are also reflected by the presence of two regimes different from those for clipped grass field. / The double trace moment technique was performed on the inertial subrange of the temperature and velocity fields measured over clipped grass to obtain the parameters characterizing the multifractal fields. The variability of the parameters with the atmospheric stability was investigated and no apparent difference between stable and unstable conditions was found. The results reveal that those fields are universal multifractals with the characteristic parameters $ alpha$ near 1.7 and C$ sb1$ ranging from 0.04 to 0.12, implying that the fields can be modeled by a log-Levy process with unbounded singularities. We also found that the critical moment q$ rm sb{s}$ for the multifractal phase transition is close to 4.

No description available.

O presente trabalho tem por objetivo aplicar a análise de confiabilidade estrutural a um edifício alto submetido à ação do vento considerando o conforto humano na avaliação dos modos de falha. Para isso, foram consideradas como variáveis aleatórias: a velocidade máxima do vento no topo do edifício cuja distribuição de probabilidade é a distribuição de Gumbel para máximos e o módulo de elasticidade do concreto com modelo de probabilidade normal. Realizou-se a análise para dois modos de falha: o deslocamento excessivo no topo do edifício, com base na NBR 15575-2/2013, e a aceleração máxima para verificação do conforto humano de acordo com a NBR 6123/2013. Posteriormente, foi realizada uma análise conjunta dos modos de falha aplicados em série. O método utilizado foi o FORM – First Order Reliability Method com algoritmo HLRF, implementado em ambiente Matlab, para o edifício teórico CAARC. Verificou-se grandes discrepâncias entre a probabilidade de falha para os dois modos considerados. Para a aceleração máxima, encontrou-se valores práticos de ponto de projeto e probabilidade de falha. No entanto, o deslocamento horizontal de 3 centímetros resultou em uma probabilidade de falha extremamente alta para valores de velocidade de vento baixos, concluindo-se que, para o edifício alto do problema, o limite normativo tende a ser facilmente extrapolado. À vista disso, o parâmetro de deslocamento horizontal baseado na altura total do edifício também foi estudado. Tal análise resultou em uma probabilidade de falha maior que a da aceleração, no entanto, apresentando valores de ponto de projeto consistentes. / The present work aims to apply structural reliability analysis to a tall building subjected to wind load considering human comfort in the evaluation of failure modes. For this purpose, the following random variables were considered: the maximum wind speed at the top of the building whose probability distribution is the Gumbel distribution for maximum and the modulus of elasticity of concrete with normal distribution. The analysis was conducted for two failure modes: excessive displacement on the top of the building, which is based on NBR 15575/2013, and the maximum acceleration for verification of the human comfort according to NBR 6123/2013. A joint analysis of failure modes applied in series was performed. The method used was the FORM - First Order Reliability Method with HLRF algorithm, implemented in Matlab environment, for the theoretical building CAARC. Large discrepancies between the failure probabilities of the two modes considered were found. For maximum acceleration, the design point value and the failure probability found were practical results. However, the horizontal displacement of 3 centimeters resulted in an extremely high probability of failure for low wind speed values, concluding that, for the tall building of the problem, the code limit tends to be easily extrapolated. Hence, the horizontal displacement parameter based on the total height of the building was also studied. Such analysis resulted in a failure probability greater than the acceleration one, however, presenting consistent design point values.

Este trabalho descreve o desenvolvimento de um medidor de velocidade de vento aplicando técnicas da teoria de erros, como a correlação cruzada, bem como sensores de ultrassom. Ele pode ser utilizado em encanamentos, onde se busca obter a velocidade de fluídos, em estações climáticas, em aeroportos, no momento de se aplicar pesticidas assim como em fazendas eólicas, onde o conhecimento da velocidade do vento é necessário, dentre outras aplicações. O sistema desenvolvido é composto pela placa de desenvolvimento de0-nano, uma placa de circuito impresso (PCB) para aquisição de sinais e dois pares de sensores de ultrassom. A PCB também possui circuitos para excitação dos sensores de ultrassom bem como comunicação com o PC para armazenamento dos sinais amostrados. A teoria de erros foi discutida e os resultados do protótipo foram analisados utilizando métodos probabilísticos necessários para verificar a incerteza. Dentro da FPGA da placa de0-nano foi desenvolvido um sistema baseado no processador NIOS, o qual foi construído através da ferramenta QSYS. Além disso, blocos em VHDL foram desenvolvidos para interfaceamento do sistema com o PC. Um pequeno túnel de vento foi construído e um anemômetro de mão foi adquirido para validar o protótipo. Simulações foram realizadas no Microsoft Excel 2007 para comparar a correlação cruzada dada pelo protótipo e a teoria. É comum que DSPs e Microprocessadores estejam dentro de medidores de velocidade do vento, no entanto um sistema desenvolvido com FPGA aumenta a velocidade de processamento devido ao paralelismo. Blocos descritos em VHDL podem ser facilmente replicados dentro da FPGA e existe uma grande coleção de bibliotecas, literatura extensiva e exemplos de código para o NIOS. Com isso há um menor tempo de desenvolvimento de um protótipo/sistema e há facilidade de desenvolver um System on Chip (SoC) de sistemas baseados em FPGA, reduzindo os custos de um futuro produto comercial. / This work describes the development of one axis wind speed measurement equipment applying error theory techniques, as the cross correlation, and ultrasound sensors. It can be used in tubes, where fluid speed knowledge is needed, climate stations, airports, in the moment of applying pesticides and in wind farms, where wind speed knowledge is necessary. The built prototype is a connected set of a de0-nano development board, a signal acquisition printed circuit board and two pairs of ultrasound sensors. The PCB also has circuits for ultrasound sensors exciting and PC communications to store the sampled signals. The error theory was discussed and the prototype's results were developed using probabilistic methods needed to verify the uncertainty. Inside de0-nano board FPGA chip, a system based in NIOS processor was developed and built through QSYS tool. There are some blocks described in VHDL for PCB interfacing. A small wind tunnel was built and a hand anemometer was acquired to validate the proposed system. Simulations were done in Microsoft Excel 2007 to compare the cross correlation given by the prototype and the theory. It is common DSPs and microprocessors inside this type of equipments to measure wind speed, but a system developed with a FPGA increases the processing speed due to parallelism. Blocks described in VHDL can be easily replicated inside the FPGA and there is a large collection of libraries, extensive literature and code examples for NIOS. Thereby there are small system/prototype developing times and there is an easy development of a System on Chip (SOC) of FPGA based systems, reducing the costs for a future commercial product.

O presente trabalho tem por objetivo aplicar a análise de confiabilidade estrutural a um edifício alto submetido à ação do vento considerando o conforto humano na avaliação dos modos de falha. Para isso, foram consideradas como variáveis aleatórias: a velocidade máxima do vento no topo do edifício cuja distribuição de probabilidade é a distribuição de Gumbel para máximos e o módulo de elasticidade do concreto com modelo de probabilidade normal. Realizou-se a análise para dois modos de falha: o deslocamento excessivo no topo do edifício, com base na NBR 15575-2/2013, e a aceleração máxima para verificação do conforto humano de acordo com a NBR 6123/2013. Posteriormente, foi realizada uma análise conjunta dos modos de falha aplicados em série. O método utilizado foi o FORM – First Order Reliability Method com algoritmo HLRF, implementado em ambiente Matlab, para o edifício teórico CAARC. Verificou-se grandes discrepâncias entre a probabilidade de falha para os dois modos considerados. Para a aceleração máxima, encontrou-se valores práticos de ponto de projeto e probabilidade de falha. No entanto, o deslocamento horizontal de 3 centímetros resultou em uma probabilidade de falha extremamente alta para valores de velocidade de vento baixos, concluindo-se que, para o edifício alto do problema, o limite normativo tende a ser facilmente extrapolado. À vista disso, o parâmetro de deslocamento horizontal baseado na altura total do edifício também foi estudado. Tal análise resultou em uma probabilidade de falha maior que a da aceleração, no entanto, apresentando valores de ponto de projeto consistentes. / The present work aims to apply structural reliability analysis to a tall building subjected to wind load considering human comfort in the evaluation of failure modes. For this purpose, the following random variables were considered: the maximum wind speed at the top of the building whose probability distribution is the Gumbel distribution for maximum and the modulus of elasticity of concrete with normal distribution. The analysis was conducted for two failure modes: excessive displacement on the top of the building, which is based on NBR 15575/2013, and the maximum acceleration for verification of the human comfort according to NBR 6123/2013. A joint analysis of failure modes applied in series was performed. The method used was the FORM - First Order Reliability Method with HLRF algorithm, implemented in Matlab environment, for the theoretical building CAARC. Large discrepancies between the failure probabilities of the two modes considered were found. For maximum acceleration, the design point value and the failure probability found were practical results. However, the horizontal displacement of 3 centimeters resulted in an extremely high probability of failure for low wind speed values, concluding that, for the tall building of the problem, the code limit tends to be easily extrapolated. Hence, the horizontal displacement parameter based on the total height of the building was also studied. Such analysis resulted in a failure probability greater than the acceleration one, however, presenting consistent design point values.

Este trabalho descreve o desenvolvimento de um medidor de velocidade de vento aplicando técnicas da teoria de erros, como a correlação cruzada, bem como sensores de ultrassom. Ele pode ser utilizado em encanamentos, onde se busca obter a velocidade de fluídos, em estações climáticas, em aeroportos, no momento de se aplicar pesticidas assim como em fazendas eólicas, onde o conhecimento da velocidade do vento é necessário, dentre outras aplicações. O sistema desenvolvido é composto pela placa de desenvolvimento de0-nano, uma placa de circuito impresso (PCB) para aquisição de sinais e dois pares de sensores de ultrassom. A PCB também possui circuitos para excitação dos sensores de ultrassom bem como comunicação com o PC para armazenamento dos sinais amostrados. A teoria de erros foi discutida e os resultados do protótipo foram analisados utilizando métodos probabilísticos necessários para verificar a incerteza. Dentro da FPGA da placa de0-nano foi desenvolvido um sistema baseado no processador NIOS, o qual foi construído através da ferramenta QSYS. Além disso, blocos em VHDL foram desenvolvidos para interfaceamento do sistema com o PC. Um pequeno túnel de vento foi construído e um anemômetro de mão foi adquirido para validar o protótipo. Simulações foram realizadas no Microsoft Excel 2007 para comparar a correlação cruzada dada pelo protótipo e a teoria. É comum que DSPs e Microprocessadores estejam dentro de medidores de velocidade do vento, no entanto um sistema desenvolvido com FPGA aumenta a velocidade de processamento devido ao paralelismo. Blocos descritos em VHDL podem ser facilmente replicados dentro da FPGA e existe uma grande coleção de bibliotecas, literatura extensiva e exemplos de código para o NIOS. Com isso há um menor tempo de desenvolvimento de um protótipo/sistema e há facilidade de desenvolver um System on Chip (SoC) de sistemas baseados em FPGA, reduzindo os custos de um futuro produto comercial. / This work describes the development of one axis wind speed measurement equipment applying error theory techniques, as the cross correlation, and ultrasound sensors. It can be used in tubes, where fluid speed knowledge is needed, climate stations, airports, in the moment of applying pesticides and in wind farms, where wind speed knowledge is necessary. The built prototype is a connected set of a de0-nano development board, a signal acquisition printed circuit board and two pairs of ultrasound sensors. The PCB also has circuits for ultrasound sensors exciting and PC communications to store the sampled signals. The error theory was discussed and the prototype's results were developed using probabilistic methods needed to verify the uncertainty. Inside de0-nano board FPGA chip, a system based in NIOS processor was developed and built through QSYS tool. There are some blocks described in VHDL for PCB interfacing. A small wind tunnel was built and a hand anemometer was acquired to validate the proposed system. Simulations were done in Microsoft Excel 2007 to compare the cross correlation given by the prototype and the theory. It is common DSPs and microprocessors inside this type of equipments to measure wind speed, but a system developed with a FPGA increases the processing speed due to parallelism. Blocks described in VHDL can be easily replicated inside the FPGA and there is a large collection of libraries, extensive literature and code examples for NIOS. Thereby there are small system/prototype developing times and there is an easy development of a System on Chip (SOC) of FPGA based systems, reducing the costs for a future commercial product.