"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).

Not available / text

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.)

5th IFAC Symposium on Mechatronic Systems, Marriott Boston Cambridge, Cambridge, MA, USA, Sept 13-15, 2010

No description available.

In the analysis of plates and beams, in-plane velocities have been assumed to be small and negligible. This was nearly an unavoidable assumption due to the fact that the in-plane velocity was near impossible to determine accurately with conventional techniques. This assumption needs to be checked experimentally. In addition, general engineering structures, such as machines, TV towers, buildings, etc., have major in-plane motions that are actually out-of-plane motions as viewed from another vantage point. These also need to be measured. Now with the use of a Laser Doppler Vibrometer the development of a method to measure three-dimensional velocities has provided the ability to measure in-plane velocities accurately. This thesis outlines the methods used for such three-dimensional extraction and gives an example of its use. Not only is the final three-dimensional method described, but the whole process of developing the method is outlined. This will hopefully provide insight into the difficulties associated with this method as well as prevent other researchers from following similar fruitless approaches. / Master of Science

Operating speed is one of the best performance measures that can tell transportation agencies how well or how poorly the transportation system is functioning. Fluctuating operating speeds often mean there is a design flaw or something about the physical road design that violates drivers' expectations. A primary example of this is a horizontal curve on a highway that had a reduced recommended advisory speed. Traditionally, researchers and transportation agencies measure operating speeds along the approach tangent to a horizontal curve and at the midpoint of the curve. This thesis looks at the significance of alternate measuring locations within the curve. It also analyzes the difference between the 85th percentile maximum speed reduction and the more traditional measure of the reduction in 85th percentile speeds, which is used as an indicator of safety. / Graduation date: 2012

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.

When the light passes through optical elements it can cause deformation of wavefront light due to the damage of materials and optical aberrations. The deformation leads to unprecise imaging and deformation of an image. The diploma work mentions wavefront sensing techniques which are important for determination inappropriate errors of optical elements and the specification of their properties. The purpose of the master's thesis is to suggest and investigate wavefront sensing methods after the light passes through the optical element while using the digital micromirror device. The work deals with the topic of wavefront aberrations and geometric optical defects of optical elements. Different kinds of commercial products determined for wavefront sensing are described too.