This thesis presents a study concerning stop consonant to vowel transitions which are modeled making use of acoustic tube model. Characteristics of the stop consonant to vowel transitions are tried to be obtained first. Therefore several transitions including fricative to vowel transitions are examined based on spectral and time related properties. In addition to these studies, x-ray snapshots, lip videos and also experiments including subjects are used to intensify the characterization, from the production and the perception side of views. As results of these studies the plosive to vowel transitions are observed to be uttered by exponential vocal tract movements and the perception mechanism is observed to be highly related with exponential spectral changes. A model, based on the acoustic tube model, is tried to be established using the knowledge and the experience gained during characterization therefore proposed model involves the vocal tract parameters observed in characterization part. Finally, plosive to vowel transitions including three types of plosives (alveolar, labial and velar) are synthesized by the proposed model. The formants of the synthesized sounds are compared with the formants of the natural sounds. Also the intelligibility tests of these sounds are done. Performance evaluation tests show the proposed model&rsquo / s performance to be satisfactory.

Finite element method and strip method are two widely used techniques for analyzing steel plate shear wall (SPSW) systems. Past research mostly focused on the prediction of lateral load capacity of these systems using these numerical methods. Apart from the lateral load carrying capacity, the lateral stiffness of the wall system needs to be determined for a satisfactory design. Lateral displacements and the fundamental natural frequency of the SPSW system are directly influenced by the lateral stiffness. In this study the accuracy of the finite element method and strip method of analysis are assessed by making comparisons with experimental findings. Comparisons revealed that both methods provide in general solutions with acceptable accuracy. While both methods offer acceptable solutions sophisticated computer models need to be generated. In this study two alternative methods are developed. The first one is an approximate hand method based on the deep beam theory. The classical deep beam theory is modified in the light of parametric studies performed on restrained thin plates under pure shear and pure bending. The second one is a computer method based on truss analogy. Stiffness predictions using the two alternative methods are found to compare well with the experimental findings. In addition, lateral stiffness predictions of the alternate methods are compared against the solutions provided using finite element and strip method of analysis for a class of test structures. These comparisons revealed that the developed methods provide estimates with acceptable accuracy and are simpler than the traditional analysis techniques.

Noise, which is a noteworthy problem in the world of workers, influences the health, safety, productivity and efficiency of those working in heavy industries and especially those working in petroleum industry. The objective of this study is to reassess the protective measures, taken previously by the company, from the point of view of the negative effects of noise on the workers. For this purpose, two approaches are adopted. Firstly, through questionnaires (response rate: 86%) distributed to workers, their subjective rating of, the noise levels to which they are exposed, the factors affecting their working efficiency and, their working conditions are searched. Secondly, noise levels, in the buildings rated as highly and very highly noisy, are measured by sound level meter. Self-exposure of 28 workers is measured by dosimeter. The overall ambient noise level of the 11 buildings and effect of noise on the working efficiency of the workers working in these buildings were respectively found to be moderate and slightly affected. The workplace index was 3 (out of 5). The working conditions index was on the average 4 (out of 5). The Leq values measured in six of the buildings were found to be in the range of 66, 8 &ndash / 100, 0 dBA. 12 out of 28 workers were observed to be exposed to noise levels greater than 80 dBA. The objective (noise measurements) and subjective (questionnaire) results obtained at the end of the afore-mentioned approaches will be of help in the orientation of the workers while estimating their work efficiency and will also serve as a data base for the planning strategy of the interested company.

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 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.