Incorporating safety in the design of a highway is one of the foremost duties of a design engineer. Design guidelines provide standards that help engineers include safety in the design of various geometric features. However, design guidelines are not frequently revised and do not accommodate for the frequent changes in vehicle design. One such example is the change in vehicle headlamps. These changes significantly impact the illuminance provided on the road and in turn the design formula. Roadway visibility is critical for nighttime driving. In the absence of roadway lighting, vehicle headlamps illuminate the road ahead of a vehicle. Sag vertical curve design depends on the available headlight sight distance provided by the 1 degree upward diverging headlamp beam. The sag curve design formulas were developed in the early 1940s when sealed beam headlamps were predominant. However, headlamps have changed significantly and modern headlamps project less light above the horizontal axis. In this research, the difference in illuminance provided by sealed beam headlamps and modern headlamps was examined. For the theoretical analysis, three different sag curves were analyzed. On these curves, about 26 percent reduction in illuminance was observed at a distance equal to the stopping sight distance when comparing sealed beam to modern headlamps. A change in the headlamp divergence angle from 1.0 degree to 0.85 degree will provide the required illuminance on the road when using modern headlamps. A field study was performed to validate the theoretical calculations. It was observed that for modern headlamps, a divergence angle less than 1 degree and greater than 0.5 degrees will provide illuminance values comparable to sealed beam headlamps. As a part of this research, a preliminary study, examining the impact of degraded headlamp lenses on the illuminance provided on sag vertical curves was conducted. A significant reduction in illuminance reaching the roadway on sag curves was observed, due to headlamp lens degradation.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (p. 243-256).

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on December 30, 2009). Thesis advisor: Dr. William Banks. Includes bibliographical references.

Thesis (doctoral)--Westfälischen Wilhelms-Universität zu Münster, 1911. / Cover title. Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 61-64). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--Worcester Polytechnic Institute. / Includes bibliographical references (leaves 50-54).

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 65-68).

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). "October 2009." Includes bibliographical references (p. 184-196). Also available via the World Wide Web.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: multiplication; OTF; optimal extension fields; finite fields; optimal tower fields; cryptography; OEF; inversion; finite field arithmetic; elliptic curve cryptography. Includes bibliographical references (p. 50-52).

An introduction on random numbers, their history and applications is given, along with explanations of different methods currently used to generate them. Such generators can be of different kinds, and in particular they can be based on physical systems or algorithmic procedures. The latter type of procedures gives rise to pseudo-random number generators. Specifically, several such generators which are based on elliptic curves are examined. Therefore, in order to ease understanding, a basic primer on elliptic curves over fields and the operations arising from their group structure is also provided. Empirical tests to verify randomness of generated sequences are then considered. Afterwards, there are some statistical considerations and observations about theoretical properties of the generators at hand, useful in order to use them optimally. Finally, several randomly generated curves are created and used to produce pseudo-random sequences which are then tested by means of the previously described generators. In the end, an analysis of the results is attempted and some final considerations are made.