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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Edge-matched segmented mirrors for adaptive optics.

Gleckler, Anthony Duane January 1994 (has links)
The use of segmented mirrors in astronomy and adaptive optics is increasing as the ability to measure and control the position of the individual segments to a fraction of the wavelength of light becomes possible. A novel technique is presented in which the relative piston error of adjacent segments is measured using inductive edge-sensors. This technique alleviates the need to have an absolute piston sensor for each of the segment. Modelling of the performance of such a mirror for the case of correcting atmospheric turbulence is presented. This modelling shows that an edge-matched segmented mirror can correct the piston errors in the wavefront even though it does not sense them directly. In addition to this modelling, an experiment. which demonstrates the utility of this technology for adaptive secondary mirrors is described. The results of this experiment, which demonstrates for the first time that an edge-matched mirror can correct for atmospheric piston errors, are presented.
2

An investigation into the viability of a multimedia intelligent tutoring system

Hannigan, Cecilia Marie January 2001 (has links)
No description available.
3

Design, implementation, and testing of an adaptive optics test-bench

Wallace, Brian Peter. 10 April 2008 (has links)
No description available.
4

Adaptive reuse of abandoned historic churches: building type and public perception

Ahn, You Kyong 15 May 2009 (has links)
This study investigates the adaptive reuse of abandoned historic churches. Since churches serve as cultural heritage symbols, the public becomes concerned with maintaining the historic integrity of these buildings. More so, this phenomenon is accentuated when the church is recognized as a historic building by the National Register of Historic Places. Yet, more and more churches are abandoned due to decreases in congregation size and financial constraints that limit the maintenance of the churches. Adaptive reuse projects of these abandoned churches are often initiated to save and preserve these buildings. This research focuses on the question: What is the public perception of critical architectural features of a historic church when it is adapted to a new function (new building type)? To support the importance of this question, the study integrates two major bodies of knowledge. The first body of literature is research conducted in cognitive science focusing on human perception of environments. The second body of literature is on historic preservation with a focus on adaptive reuse. The integration of these literature reviews is further demonstrated in the analysis of examples of past and recent adaptive reuse projects of religious buildings. Following this investigation, a conceptual model was developed to illustrate how research variables and hypotheses were made based on the findings from this literature review. To test the research question and its hypotheses, two prototypes of historic churches were developed. Then, typologies of changes in the important architectural features (interior volume and light quality) of the churches were constructed from examples of adaptively reused historic churches listed in the National Register of Historic Places. These typologies were developed to represent various building types (e.g., community/ cultural, institutional, commercial, and residential). Finally, an experiment was conducted to test public perceptions of acceptable and desirable degree of each reuse and the degree of retaining religious origins by use of these typologies. The findings of this research illustrate the importance of public perception and building type in adaptive reuse projects. This in turn provides theoretical and practical implications for adaptive reuse projects in the field of historic preservation.
5

Adaptive reuse of abandoned historic churches: building type and public perception

Ahn, You Kyong 15 May 2009 (has links)
This study investigates the adaptive reuse of abandoned historic churches. Since churches serve as cultural heritage symbols, the public becomes concerned with maintaining the historic integrity of these buildings. More so, this phenomenon is accentuated when the church is recognized as a historic building by the National Register of Historic Places. Yet, more and more churches are abandoned due to decreases in congregation size and financial constraints that limit the maintenance of the churches. Adaptive reuse projects of these abandoned churches are often initiated to save and preserve these buildings. This research focuses on the question: What is the public perception of critical architectural features of a historic church when it is adapted to a new function (new building type)? To support the importance of this question, the study integrates two major bodies of knowledge. The first body of literature is research conducted in cognitive science focusing on human perception of environments. The second body of literature is on historic preservation with a focus on adaptive reuse. The integration of these literature reviews is further demonstrated in the analysis of examples of past and recent adaptive reuse projects of religious buildings. Following this investigation, a conceptual model was developed to illustrate how research variables and hypotheses were made based on the findings from this literature review. To test the research question and its hypotheses, two prototypes of historic churches were developed. Then, typologies of changes in the important architectural features (interior volume and light quality) of the churches were constructed from examples of adaptively reused historic churches listed in the National Register of Historic Places. These typologies were developed to represent various building types (e.g., community/ cultural, institutional, commercial, and residential). Finally, an experiment was conducted to test public perceptions of acceptable and desirable degree of each reuse and the degree of retaining religious origins by use of these typologies. The findings of this research illustrate the importance of public perception and building type in adaptive reuse projects. This in turn provides theoretical and practical implications for adaptive reuse projects in the field of historic preservation.
6

Analysis of optical wavefront reconstruction and deconvolution in adaptive optics /

Luke, David Russell, January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 165-184).
7

Global optimization algorithms for adaptive infinite impulse response filters

Lai, Ching-An. January 2002 (has links)
Thesis (Ph. D.)--University of Florida, 2002. / Title from title page of source document. Includes vita. Includes bibliographical references.
8

Switching adaptive filter structures for improved performance /

Zakaria, Gaguk, January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 140-143). Also available via the Internet.
9

Subband adaptive filters.

Ryan, James Gregory, Carleton University. Dissertation. Engineering, Electrical. January 1992 (has links)
Thesis (M. Eng.)--Carleton University, 1992. / Also available in electronic format on the Internet.
10

Point spread function reconstruction for the adaptive optics system ALFA and its application to photometry

Weiss, Alexander Robert. January 2003 (has links) (PDF)
Heidelberg, University, Diss., 2003.

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