Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--Massachusetts Institute of Technology. / Vita. Includes bibliographical references (p. 337-348).

Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2006. / Stasko, John, Committee Member ; Owen, Henry, Committee Member ; Merkle, Ralph, Committee Member ; Lee, Wenke, Committee Member ; Ahamad, Mustaque, Committee Chair.

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves 121-122).

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: visual; clutter; measurement; reduction; information; visualization; air traffic. Includes bibliographical references. (p.64-66)

Thesis (Masters Diploma (Electrical Engineering)--Cape Technikon, Cape Town, 1993 / In the last decade the advertising industry has developed into an advanced science which increasingly relies on the use of electronic utilities and modern technology. The advent of the microcontroller has made it possible to incorporate electronic intelligence into advertising utilities. This thesis describes the design, development and functioning of a stand alone programmable electronic message display as required by the Electrical Engineering Department of the Cape Technikon.

Micro light-emitting diode (microLED) technologies have been rapidly developing in the past decade and stand to be the prominent display technology for high-brightness applications. MicroLED microdisplays are particularly well-suited for systems that compete with high ambient light, such as augmented reality headsets and smartwatches that reflect light from the sun. However, there are several technological issues to overcome before microLED cost can be driven to a point that enables widespread commercial use. This dissertation covers the current microLED technological landscape, key issues to overcome, and an in-depth discussion on microLED performance and applications using modeled and experimentally fabricated microLEDs. The first experiment focuses on microLED fabrication fidelity and methods to overcome the challenge of defect-free displays. Current ultra-high definition display resolution standards require approximately 25 million individual microLED emitters with an expected zero dead pixels. To better identify defect states at early stages of fabrication, this dissertation presents methods using photoluminescence and cathodoluminescence that can identify dry-etching related damage to GaN/InGaN microLEDs that result in dead pixels. Expanding on fabrication fidelity, the second study in this dissertation examines surface recombination losses in etched GaN/InGaN microLEDs from nitrogen vacancy trap states. As microLED emitter size decreases, the ratio of etched surface area to emitter area size increases and injected current recombining at surface trap states increases causing large efficiency losses. To combat this, this study examines pGaN contact geometry selections and the influence on surface recombination losses. In particular, the results show that there is a strong dependence on efficiency for a desired output power in relation to current density. Utilizing the fabrication knowledge from the first two studies, applications and implementations of microLED microdisplays as a structured illumination microscopy light source within miniaturized microscopes are presented. There is discussion on future miniaturization strategies and next steps to improve device performance. Finally, this dissertation includes a short discussion on a display-adjacent technology, organic field-effect transistors (OFETs). An investigation on the electrostatic discharge resilience of parylene in OFETs is presented for applications in flexible high-voltage thin-film transistors.

No description available.

Chunking is defined as the process of organizing information into multi-item clusters appropriate to solving a particular task. It was hypothesized that dynamic information displays could be formatted to group related items. This formatting would facilitate chunking and, in turn, serve to reduce task difficulty. Two novel display grouping formats were evaluated. In Tight Spatial Proximity, iconic symbols belonging to the same class were rearranged so that they were located proximally on the display. In Chunks-In-Sequence (CIS), symbol classes were presented sequentially, but all members within a symbol class were presented simultaneously. Ten individuals participated in Experiment 1. During a trial, 2 to 25 symbols (e.g., cannon, radar, etc.) were presented briefly on a computer display. Displayed symbols were sampled from a larger symbol set (Le., 64 total symbols) representing eight unique symbol classes (e.g., military, highway signs, etc.). Participants then viewed a prompt and responded "yes" or "no" to indicate whether the probe symbol was a member of a class that had been presented during that trial. Results indicated that grouping formats helped participants chunk symbols into appropriate classes and solve the classification task with reduced error rates and subjective workload. Experiment 2 was similar to Experiment 1, with the exception that participants were tasked to remember each symbol presented during a trial rather than just the symbol class names. This task required forming chunks, storing them in memory, and then parsing the chunks into component items. Results indicated that display grouping formats reduced subjective workload, but not error rates. Considering both experiments, it is concluded that spatially or temporally grouped symbols can be chunked more easily than information displayed in a non-grouped format. However, grouping formats will not help operators parse these information chunks given detailed component recall demands. / Ph. D.

When dot-matrix characters are rotated, as might be the case in a moving map display, their dot-matrix patterns are distorted and their legibility is thus affected. In this experiment, 16 subjects performed a random search task, in which they were asked to look for a target in a random character pattern. The independent variables were the direction (clockwise or counterclockwise) and the angle of stimulus image rotation, and the target character's distance from the center of screen, which was also the center of rotation; the dependent variables were response time and response correctness. Significant effects were found in the angle of rotation, the target character's distance from the center, and the target character. The results indicate that (1) no angle-dependent mechanism is involved in performing this task and the angle of rotation influences recognition mainly through the distortion of dot-matrix patterns, (2) the target character's (radial) distance from the center of screen is the determining factor for search time, while the x and y coordinates of the target contributed to dot-matrix pattern distortion, and (3) the target characters interacted differently with the angle and distance factors to determine the extent of distortion and their legibility. Means to quantify the extent of distortion were discussed and the direction for future research is offered. / Master of Science