Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (p. 154-165).

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains ix, 133 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 116-117).

Thesis (M.S.)--Brigham Young University. Dept. of Computer Science, 2005. / Includes bibliographical references (p. 65-68).

Thesis (Ph. D.)--Carnegie Mellon University, 2001. / "May 2001." Includes bibliographical references (p. 273-282).

Thesis (Ed.D.)--University of Delaware, 2007. / Principal faculty advisor: Fred T. Hofstetter, School of Education. Includes bibliographical references.

Most interaction with computers today takes place in a two dimensional environment. Even when using three dimensional graphics applications, input is often still restricted to two dimensions. Many believe that the use of three dimensional input devices will alleviate this restriction and allow for a much more natural human-machine dialog. This thesis seeks to establish how factors dealing with visual feedback and task structure affect the ability to perform interactive tasks in a three dimensional virtual environment. The factors investigated were stereoscopic vision, motion parallax, stimulus arrangement and stimulus complexity. Four tasks were studied. These tasks were: point location, docking, line tracing and curve tracing. All the tasks used a six degree of freedom input device to control a pointer in a three dimensional virtual environment. Four experiments corresponding to the four tasks were conducted to investigate these factors. Among other things the results showed the following. Stereoscopic vision provided a strong benefit to positioning-based tasks, but this benefit was weakened in the case of tracing tasks. Motion parallax via head-tracking often had no effect upon task performance and where an effect was found it was often detrimental. The position of stimuli influenced performance across all of the tasks. The orientation of stimuli influenced performance in the task in which it was varied. / Science, Faculty of / Computer Science, Department of / Graduate

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This study describes algorithms for the solution of several single facility location problems with maximin or minimax objective functions. Interactive computer graphical algorithms are presented for maximizing the minimum rectilinear travel distance and for minimizing the maximum rectilinear travel distance to a number of point demands when there exist several right-angled polygonal barriers to travel. For the special case of unweighted rectilinear distances with barriers, a purely numerical algorithm for the maximin location problem is described. An interactive computer graphical algorithm for maximizing the minimum Euclidean, rectilinear, or general 1p distance to a number of polygonal areas is described. A modified version of this algorithm for location problems with the objective of minimizing the maximum cost when the costs are non-linear monotonically decreasing functions of distance is presented. Extension of this algorithm to problems involving the minimization of the maximum cost when the costs are functions of both distance and direction is discussed using asymmetric distances. / Thesis / Doctor of Philosophy (PhD)

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No description available.