Kidznotes is a non-profit organization that provides free after-school music education for underserved populations in urban North Carolina. Kidznotes bases its organizational model on El Sistema; a state-funded music education program started in Venezuela by economist and educator José Abreu in 1987. Kidznotes provides free instruction, a daily snack, instruments, and transportation, all funded by corporate sponsors, concerts performed by Kidznotes’ students, and Kidznotes fundraising events put on by corporate sponsors. As a former employee of the program, and through the fieldwork I conducted at Kidznotes’ Raleigh and Durham summer camps, I gained an immersion and acute awareness to the content and structure of Kidznotes’ soundscapes. The students of Kidznotes are predominately elementary-age, come from low-income neighborhoods in Raleigh and Durham, and attend either Title I or non-profit charter schools in the area. They come to Kidznotes three days during the school week for two hours after a 7-hour school day, and for two hours in the morning on Saturdays. The short time spent in the Kidznotes environment was just a glimpse of what their students experience daily with those that are intended to help them. I theorize that the distinctive aural space of Kidznotes allows for compartmentalization in the minds of underprivileged children, separating their everyday lives from their lives at Kidznotes so that they are given the mental space and sonic authority to assert themselves into the soundscape. This assertion, I propose, is a metaphorical way of challenging the convoluted soundscapes of the outside world, filled with overlapping and contradictory messages children hear that shape their self-perception. This study will then illuminate the ways in which intimacy and music-making as they present themselves within the sonic space of underprivileged youth, make programs like Kidznotes in the North Carolinian context potentially useful for helping minority and low-income children form a healthier sense of self. / A Thesis submitted to the College of Music in partial fulfillment of the requirements for the degree of Master of Music. / Spring Semester 2019. / April 1, 2019. / Children's music, Durham, El Sistema, North Carolina, Raleigh, Sound Studies / Includes bibliographical references. / Frank Gunderson, Professor Directing Thesis; Margaret Jackson, Committee Member; John Reynolds, Committee Member.

For the first time an ocean model is used to assimilate oceanic tomography data in an upper ocean model of the northeast Pacific with the goal of estimating the time independent density field, and thus the slow manifold circulation structure. / The assimilation procedure works by minimizing the cost function, which generalizes the misfit between the observations and their model counterparts, in a least-squares sense, plus a penalty term. This minimization is done consistently with the constraint that the model dynamics must be exactly satisfied. The model consists of integrating the model equations forward in time over the period which data are going to be assimilated. Data misfits between the model and the observation are then calculated and the adjoint equations of the model are integrated backward using the data misfits as forcing. It is necessary to determine the gradient of the cost function with respect to the control variables (the density field). The gradient is found using the model and adjoint variables and it is used in a minimization algorithm to determine a new density field. The minimization procedure utilizes a limited memory quasi-Newton method. / The results indicate that the assimilation procedure works very well. For the twin experiments, the final estimated density recovers the Levitus density field as expected and as fast as in 10 iterations. For the experiments with the Navy layered ocean circulation model (NRLM) output, the density can be estimated through the assimilation procedures. The estimated density field improves the the Levitus climatological density data which are biased and makes the subtropical gyre stronger in the northeast Pacific region. / The proof of the identity between the discretization of the continuous adjoint equations and the adjoint equations which are from discretized model equations with the Arakawa C has been carried out. / Source: Dissertation Abstracts International, Volume: 56-07, Section: B, page: 3667. / Major Professor: James J O'Brien. / Thesis (Ph.D.)--The Florida State University, 1995.

This dissertation describes the development of an evaluation tool that can be used by an acoustican during the design stage of enclosures used for unassisted speech. Enclosures include lecture theatres, lecture halls and speech auditoriums. The tool is designed to enable Acousticians to be able to manipulate various acoustical parameters such as the geometry and the materials or construction selection to gauge the impact on speech performance. The tool can also be used to evaluate the performance of speech privacy within spaces using the Speech Transmission Index. Computer simulation tools have a number of advantages over existing methods such as physical scale models for this type of evaluation. Typical advantages are in the elimination of the difficult selection of materials with appropriate scale model acoustic performance, resolution of air absorption at scale model frequencies, reduced cost in development of the model, no storage space problems, ease of modifying and duplicating the model. Scale models also present difficulties in measuring some of the indices such as Speech Transmission Index. Whilst equipment can be purchased for the measurement of STI, scale model equivalents and the impact of the change in frequencies and modulations have not been researched or published. / Currently, there are only two methods of evaluating the Speech Transmission of an enclosure: Build a full size enclosure and test; or simulate mathematically to derive the performance. At the time this thesis was commenced there were no commercial simulation programs available that could derive Speech Transmission Index information. The evaluation tool has been implemented as a computer program, based on IBM PC type computers running Microsoft WINDOWS 3.1 or later. The implementation uses the image method for the 'ray trace' algorithm. This basic image method utilises the enhancements made by a number of authors. In particular the Transformation Matrix method and homogenous coordinates have been used to improve the speed of the algorithm. Pre-computation of mutually invisible planes allows trimming the number of possible combination of rays that need to be computed. Results of physical measurement from two case studies have been compared to results of the simulation. Good correlation between the simulations and the case studies were achieved for the Speech Transmission Index and RASTI values. The accuracy of the simulation,in terms of decay based indices, is limited by the lack of sufficient tail to the calculated number of rays. Further research and implementation of hybrid techniques utilising both the image method and more traditional ray-tracing algorithms to improve the quality of the calculated decay data are required. Investigation of techniques used in photo-realism 'ray-tracing' may result in far more realistic data which is the basic input to the Speech Transmission Index calculations.

Thesis (Ph. D.)--Massachusetts Institutite of Technology and Woods Hole Oceanographic Institution, 1983. / Bibliography: p. 357-360.

Traffic is a major source of green house gases. The transport field stands for 32 % of the energy consumption and 28 % of the total CO2 emissions, where road transports alone causes 84 % of these figures. The energy consumed by a car travelling at constant speed, is due to engine inefficiency, internal friction, and the energy needed to overcome resisting forces such as aerodynamic drag and rolling resistance. Rolling resistance plays a rather large role when it comes to fuel economy. An improvement in rolling resistance of 10 % can yield fuel consumption improvements ranging from 0.5 to 1.5 % for passenger cars and light trucks and 1.5 to 3 % for heavy trucks. The objective of this thesis is to estimate the power consumption in the tyres. To do this a car tyre is modelled with waveguide finite elements. A non-linear contact model is used to calculate the contact forces as the tyre is rolling on a rough road. The contact forces combined with the response of the tyre is used to estimate the input power to the tyre structure, which determines a significant part of the rolling resistance. This is the first rolling resistance model based on physical principles and design data. The elements used in the waveguide finite elements tyre model are derived and validated. The motion of the tyre belt and side wall is described with quadratic anisotropic curved deep shell elements that includes pre-stress and the motion of the tread on top of the belt by curved quadratic, Lagrange type, homogenous, isotropic two dimensional solid elements. The tyre model accounts for: the curvature, the geometry of the cross-section, the pre-stress due to inflation pressure, the anisotropic material properties and the rigid body properties of the rim and is based on data provided by Goodyear. To validate the tyre model, mobility measurements and an experimental modal analysis have been made. The model agrees very well with point mobility measurements up to roughly 250 Hz. The eigenfrequency prediction is within five percent for most of the identified modes. The estimated damping is a bit too low especially for the anti-symmetric modes. The non-proportional damping used in the model is based on an ad hoc curve fitting procedure against measured mobilities. The non-linear contact force prediction, made by the division of applied acoustics, Chalmers University of Technology takes the tyre, the road texture and the tread pattern into account. The dissipated power is calculated through the injected power and the power dissipated within each element. It is shown that a rough road leads to more dissipation than a smooth road. A demonstration on real existing motor ways, for which rolling resistance measurements also have been made, show the potential of the method. The damping is very important for the rolling resistance prediction. The damping properties of the tyremodel are therefore updated based on measurement, equivalent structure modelling and viscoelastic material models. This updated model is slightly better at the point mobility prediction and is far better at predicting the damping level of the identified modes from the experimental modal analysis. / QC 20100722

Low-frequency noise is a health concern for workers in industrial workshops; rooms of highly varying size and dimensions, usually containing obstacles (the ‘fittings’). Low-frequency noise can be generated from sources such as reciprocating or rotating machinery, or ventilation systems. As the exposure time to the noise lengthens, workers are increasingly at risk to harmful effects such as hearing loss, communication difficulty, personal discomfort, and even nausea from induced body vibrations. Passive methods of noise control, such as absorption or barriers, generally perform better at high frequencies, but are inadequate at low frequencies. A proposed solution is active noise control, which relies on destructive interference of sound waves to reduce noise levels. However, this depends on phase, and how it is affected when sound waves encounter diffracting obstacles. In addition, the geometrical configuration of the active-control system must be optimized, which can be done using a prediction model. Sound-prediction models can also estimate the decibel level of sound within a given room configuration created by a source and the attenuation provided by the control system. Therefore, it is of interest to develop a model that predicts sound propagation in fitted rooms with phase. In this thesis, sound-pressure fields were investigated in rooms containing parallelepiped obstacles at low frequencies for which the wavelength is comparable to the obstacle dimensions. The geometric theory of diffraction (GTD) was used to model edge diffraction from an obstacle and, thus, the pressure field in shadow regions. A ray-tracing prediction model was improved to consider both the amplitude and phase of sound fields, and also the effects of edge diffraction. To validate the prediction model, experiments were performed in an anechoic chamber where a source and diffracting objects were located. In collaboration with Dr Valeau at the Université de Poitiers in France, a second model based on the finite element method (FEM) was used to compare prediction results. It was found that the phase depends mostly on the direct unblocked source-to-receiver distance. The FEM and experimental results showed that occluding objects cause phase shifts. The implementation of first-order diffraction into the ray-tracing program was successful in predicting shadow zones, thus producing a better prediction of realistic sound fields in rooms with obstacles.

This paper compares the Bohlen-Pierce scale to other octave and nonoctave-based tuning systems, drawing parallels between it and the widely used 12-equal temperament. These parallels lead to the hypothesis that there can be a set ofharmonic mIes applicable to the Bohlen-Pierce scale that are analogous to the CUITent musical practice. Those theorized mIes are then applied to some examples of the growing body of musical compositions wrtten in the BohlenPierce scale. Aiso included are supportive arguments for a preference of the use of odd-partial timbres in performance of this scale, which make the invention of the Bohlen-Pierce clarinet a major tuming point in the scale's development. Sorne of the musical works studied were written specifically for this author's performance on the Bohlen-Pierce clarinet. / Ce document compare la gamme Bohlen-Pierce d'autres systmes d'accord octave et non-octave-bass, tablissant des parallles entre soi et le systme la plus utilis, temprament de I2-gal. Ces parallles mnent la possibilit qu'il peut tre des rgles harmoniques applicables la gamme BohlenPierce qui sont analogues la pratique musicale courante. Ces rgles thorises sont alors appliques quelques exemples du corps croissant de compositions musicales crites la gamme Bohlen-Pierce. Il-y-a aussi inclus des arguments qui support la prfrence d'utilisation des timbres impair-partiels dans la performance de cette gamme, qui ferait l'invention de la clarinette Bohlen-Pierce un point tournant majeur dans la dveloppement de cette gamme. Certains compositions etudi a t ecris pour la prformance sur clarinet Bohlen-Pierce par cette auteure .

This thesis investigates the issues in deriving the Finite Di erence Time Domain Method, including the derivation of a unique method for exciting an FDTD system that is physically realistic in terms of acoustics. It is also the goal of this thesis to use the FDTD method as a tool for investigating various speaker placement con gurations for use in bass equalization. A demerit function is then developed in order to assess how well a particular equalization method performs relative to any others.

This thesis develops and analyzes efficient iterative methods for solving discretizations of the Lippmann--Schwinger integral equation for inhomogeneous acoustic scattering. Analysis and numerical illustrations of the spectral properties of the scattering problem demonstrate that a significant portion of the spectrum is approximated well on coarse grids. To exploit this, I develop a novel restarted GMRES method with adaptive deflation preconditioning based on spectral approximations on multiple grids. Much of the literature in this field is based on exact deflation, which is not feasible for most practical computations. This thesis provides an analytical framework for general approximate deflation methods and suggests a way to rigorously study a host of inexactly-applied preconditioners. Approximate deflation algorithms are implemented for scattering through thin inhomogeneities in photonic band gap problems. I also develop a short term recurrence for solving the one dimensional version of the problem that exploits the observation that the integral operator is a low rank perturbation of a self-adjoint operator. This method is based on strategies for solving Schur complement problems, and provides an alternative to a recent short term recurrence algorithm for matrices with such structure that we show to be numerically unstable for this application. The restarted GMRES method with adaptive deflation preconditioning over multiple grids, as well as the short term recurrence method for operators with low rank skew-adjoint parts, are very effective for reducing both the computational time and computer memory required to solve acoustic scattering problems. Furthermore, the methods are sufficiently general to be applicable to a wide class of problems.

This thesis investigates the issues in deriving the Finite Di erence Time Domain Method, including the derivation of a unique method for exciting an FDTD system that is physically realistic in terms of acoustics. It is also the goal of this thesis to use the FDTD method as a tool for investigating various speaker placement con gurations for use in bass equalization. A demerit function is then developed in order to assess how well a particular equalization method performs relative to any others.