Underwater acoustic channel models have been studied in the context of communication and sonar applications. Acoustic propagation channel in an underwater environment exhibits multipath, time-variability and Doppler eects. In this thesis, multipath fading channel models, underwater physical properties and sound propagation characteristics are studied. An underwater channel model for sonar applications is proposed. In the proposed model, the physical characteristics of underwater environment are considered in a comprehensive manner. Experiments /simulations were carried out using real-life data. Model parameters are estimated for a specific location, scenario and physical conditions. The channel response is approximated by fitting the model output to the recorded data. The optimization and estimation are conducted in frequency domain using Mean Square Error criterion.

In this thesis, a landing autopilot for an UAV (IAI Pioneer RQ-2) is designed based on a nonlinear MATLAB model implemented with MATLAB/Simulink. In order to control the movement of the UAV at lateral and longitudinal axes, a speed, an altitude, a heading angle (direction) and a yaw rate controllers are designed. Controller design procedure is started with determination of different trim points of the aircraft. Next, the corresponding initial states and initial inputs are obtained. The model is linearized about those trim points and the gain values are determined. The resultant gain scheduled controller is used on the non-linear model. The response of the aircraft to these controllers is tested in a constrained landing area that is constructed with respect to applicable aviation regulations. The aircraft position is investigated whether it is inside or outside of this safe landing area. If it is inside, an optimized landing path set is obtained. The steepest descent method is used for multidimensional search and parabolic fit method is used for one dimensional search (as line search) in the optimization phase. In case it is outside the defined landing area a special algorithm which takes the aircraft into the desired region is applied. In addition, the area is allowed to move as much as possible depending on the situation with special regards to the length of the runway. Also a lateral position controller is designed in order to provide the reach of the aircraft to the main landing path.

Welded steel pipes are an essential structural part of any power plant. Longer lifetimes and higher pressures in the pipes cause an increased probability of failure due to creep damage. To maintain safe operation, nondestructive evaluation techniques to detect creep damage are needed. Nonlinear acoustic techniques employing longitudinal waves have been proven to be sensitive to creep damage. The objective of this research is to develop a robust experimental procedure to reliably measure the acoustic nonlinearity parameter using longitudinal waves, and then to validate the procedure on samples of different materials and sizes. Finally the technique is applied to characterize creep damage levels around the weld of a welded steel pipe. While the experimental technique presented can only measure the relative nonlinearity, it is accurate enough to detect changes in nonlinearity due to creep damage. Measurements show an increase in nonlinearity in the heat affected zone (HAZ). Experiments after annealing the creep damaged specimen show a decrease in nonlinearity in accordance with a decrease in dislocation density. Measurements on an undamaged welded A36 steel component suggest that the heat itself is not responsible for the increase in nonlinearity.

The purpose of this study was to evaluate TAGteach as a training procedure to increase the fluency of three dance movements in a multiple baseline across behaviors design with 4 students of dance. Target behaviors included a pirouette/turn, kick, and a leap/jump, respective of the level of the class. A dance instructor was trained to implement the TAGteach procedure by the primary researcher. The targeted dance movements remained at a stable level during baseline and improved sequentially for each participant following the introduction of the TAGteach training. Implications for future research are discussed.

Exercise has many physical, cognitive, and social benefits, but the majority of older adults do not meet the recommended level of physical activity (Centers for Disease Control and Prevention, 2014). TAGteach, which combines elements of both behavioral coaching and acoustical feedback, has been demonstrated as an effective way to teach athletic skills (Fogel, Weil, & Burris, 2010; Quinn, Miltenberger, & Fogel, 2015; Stokes, Luiselli, Reed, & Fleming 2010). However, none of the current research on teaching athletic skills targeted an older population. This study evaluated TAGteach in a multiple baseline across behaviors design as a method of teaching 4 basic baton twirling skills to 3 women aged 62-73. Performance accuracy was low in baseline but improved substantially following the implementation of TAGteach. Participants also rated the intervention positively on a social validity survey. Implications and suggestions for future research are discussed.

Epigastric assistance is a breath management system for singing, that functions as a means for activating the requisite muscles needed for breathing, monitoring the action of these muscles, and regulating subglottal pressure. The manner in which the breath is managed determines how the vocal folds vibrate, this ultimately influencing the quality of sound produced. This fact alone demands a thorough investigation and understanding of breath management and the importance of the role of the epigastrium. In order for the reader to understand the role of the epigastrium in breath management, it is necessary to be familiar with the following information: 1) a definition of the epigastrium, 2) an understanding of the physiology of breathing, 3) a review of the literature that addresses breath management and the role of the epigastrium, 4) a perspective on the importance of epigastric assistance for the teacher and student, 5) an understanding of how subglottal compression affects phonation, and 6) a knowledge of scientific research that furthers the understanding of epigastric assistance. This knowledge will allow the understanding of the concept of epigastric assistance to be defined in the totality of singing. The primary focus of this treatise is a research study that measures the effects of epigastric activity upon respiratory and acoustical output. The results from the respiratory trials indicate that the subjects with a functional understanding of breath management experienced longer duration, greater volume of air, and a more efficient rate in the use of the air. However, for non-singers and those without breath management experience, there was decreased duration, less volume of air, and a less efficient rate in the use of air. Changes in the acoustics for both singers and non-singers with epigastric assistance included an increase in harmonics, greater intensity in the fundamental and harmonics, more consistency in the harmonics, and the addition of high harmonics at and above 1100 hertz. The results of this work reveal the importance of epigastric activity in singing and point to the need for further research, study, and discussion. / text

The loudspeaker system and the room interface are the two main components in any listening environment. Research will be conducted focusing on the room component using Control Room 'A' of the McGill University Recording Studio in an attempt to optimize the monitoring situation. The sound field of the room will be broken down and analyzed in both time and frequency domains. The problem areas of the room will be identified and the surfaces altered by means of absorption, reflection and diffusion.

Audio signal processing systems for converting two-channel (stereo) recordings to four or five channels are increasingly relevant. These audio upmixers can be used with conventional stereo sound recordings and reproduced with multichannel home theatre or automotive loudspeaker audio systems to create a more engaging and natural-sounding listening experience. This dissertation discusses existing approaches to audio upmixing for recordings of musical performances and presents specific design criteria for a system to enhance spatial sound quality. A new upmixing system is proposed and evaluated according to these criteria and a theoretical model for its behavior is validated using empirical measurements. / The new system removes short-term correlated components from two electronic audio signals using a pair of adaptive filters, updated according to a frequency domain implementation of the normalized-least-means-square algorithm. The major difference of the new system with all extant audio upmixers is that unsupervised time-alignment of the input signals (typically, by up to +/-10 ms) as a function of frequency (typically, using a 1024-band equalizer) is accomplished due to the non-minimum phase adaptive filter. Two new signals are created from the weighted difference of the inputs, and are then radiated with two loudspeakers behind the listener. According to the consensus in the literature on the effect of interaural correlation on auditory image formation, the self-orthogonalizing properties of the algorithm ensure minimal distortion of the frontal source imagery and natural-sounding, enveloping reverberance (ambiance) imagery. / Performance evaluation of the new upmix system was accomplished in two ways: Firstly, using empirical electroacoustic measurements which validate a theoretical model of the system; and secondly, with formal listening tests which investigated auditory spatial imagery with a graphical mapping tool and a preference experiment. Both electroacoustic and subjective methods investigated system performance with a variety of test stimuli for solo musical performances reproduced using a loudspeaker in an orchestral concert-hall and recorded using different microphone techniques. / The objective and subjective evaluations combined with a comparative study with two commercial systems demonstrate that the proposed system provides a new, computationally practical, high sound quality solution to upmixing.

This study had two purposes: first, to collect information relating to harmonic and intermodulation distortion from several sources into one comprehensive report and second, to describe and develop an interactive CD-ROM as a new method of learning harmonic and intermodulation distortion. The CD-ROM allows students to interact and control the percentage amount of harmonic and intermodulation distortion in order to "calibrate" their ears. In addition, the practical testing environment changes on a random basis to continually challenge the users. These situations allow students to interact at their own speed and therefore customize their learning development. / School of Music

There are some alternatives of artificial lift methods to increase the production of oil well or to keep it producing. Sucker rod pumping (SRP) and electrical submersible pumping (ESP) systems are selected for the design and economical evaluation of thirteen oil wells of R field. Although selected wells are already producing artificially, they are redesigned for SRP and ESP. LoadCalC software developed by Lufkin and SubPUMP developed by DSSC are used for SRP and ESP designs respectively. For economic evaluation, the rate of return (ROR) of each design is calculated for ten year period. In technical comparison, advantage of higher production ability with lower power consumption was observed in ESP applications. In wells which have lower production than 100 bpd, SRP takes the advantage as it has the ability of low volume lifting. In economical comparison it was observed that using both methods together was given better result. By increasing the number of wells that were applied ESP, 3.61% of increment in ROR was obtained relative to the present status.