The purpose of this thesis is to design and implement an active noise cancellation headphone (ANC) with a feedback controller optimally designed using the linear quadratic regulator (LQR) design approach. The controller compares the audio input signal with the measured signal from a mini microphone in the headphone, and attempts to generate a control signal so that the headphone may reproduce a clean, low noise audio sound, without being interfered by the environmental noise. The control bandwidth of the ANC headphone is 100~600Hz. The controller design emphasizes the choice of a weighting function in shaping the controller gain at different frequencies, so as to achieve maximum in-band noise cancellation and low noise amplification outside the bandwidth. The experimental result shows achievable noise cancellation of maximum 25dB within the control bandwidth and a barely noticeable slight noise amplification of maximum 6dB at high frequencies and 4.5dB at inaudible low frequencies.

Texte remanié de: Thèse de doctorat--Sciences de l'éducation--Tours, 2003. / Bibliogr. p. 315-321.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes bibliographical references and vita.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vii, 53 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 48-53).

Thesis (M.Sc.)--York University, 2007. Graduate Programme in Physics and Astronomy. / Typescript. Includes bibliographical references (leaves 67-69) Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38756

Thesis (EdD)--Open University.

Thesis (Ph. D.)--University of Chicago, December 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 126-129).

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains ix, 38 p. : ill. Includes abstract. Includes bibliographical references.

The purpose of the current study was to categorize workplace aggression into nine subtypes based on human aggression and workplace aggression literature, and to examine gender differences in engaging in these subtypes of workplace aggression. Data collected from 366 employed students showed that a significant gender difference was found only in direct workplace aggression and there were no gender differences in the other eight workplace aggression subtypes; verbal, direct, and passive workplace aggression was more frequently used than physical, indirect and active workplace aggression, respectively. Data collected from 83 employee-supervisor pairs showed that compared to supervisors' reports, female employees' self-reports tended to be higher in all eight subtypes of workplace aggression (relational workplace aggression was excluded), while male employees' self-reports were only higher in passive workplace aggression than their supervisors' reports. Male supervisors were found to report more subordinates' verbal, direct, active, and interpersonal workplace aggression than female supervisors, and male employees were reported by their immediate supervisors to engage in more active workplace aggression. Implications, limitations and conclusions were discussed.