Thesis (Ph. D.)--Texas Woman's University, 1989. / Abstract. eContent provider-neutral record in process. Description based on print version record.

Thesis (Ph. D.)--Florida State University, 1989. / Includes bibliographical references.

Thesis (Ph. D.)--University of Hawaii, 1993. / Includes bibliographical references (leaves 259-278).

Thesis (Ph. D.)--University of Hawaii, 1993. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 259-278).

This study surveyed Compact Disc-Read Only Memory (CD-ROM) technology in South African university libraries. The survey instrument used to elicit data was a questionnaire which was distributed via electronic mail (e-mail). CD-ROMs have been in the marketplace for over a decade and the extent to which South African university libraries have embraced CD-ROM technology was surveyed. Libraries offer CD-ROM services to internal staff and end-users, who in this study were students and academic staff. The study highlighted some of the CD-ROM related management issues such as budgeting, networking, resource sharing and end-user training. Survey results from the respondents indicated that they had all adopted CD-ROM technology. However, the level of CD-ROM technology and services in Historically White Institutions (HWI) and Historically Black Institutions (HBI) differed. This was evident in areas such as the year in which CD-ROMs were acquired, collection sizes and network access. The results showed that all libraries offered some form of enduser training to academic staff and students. The evolving nature of CD-ROM . technology presents a great challenge for libraries trying to keep up-to-date with the technology. This was highlighted in the open-ended questions about CD-ROM development plans and comments in general about CD-ROM technology in the different libraries. All libraries had access to the Internet and were working towards providing electronic information resources via the Web. Resource sharing and the establishment of consortiums can address the exorbitant costs of providing electronic information resources. Recommendations for further research on different aspects of CD-ROM technology were made. The development of the Internet as an information delivery system for the distribution of on-line information will emphasize the extent to which librarians and end-users are using the Internet for on-line information, as compared with CD-ROM services. Increasingly, aggregators are publishing information on the Internet and South African university libraries are already seeing this as an alternative to maintaining CD-ROM technology and services. / Thesis (M.I.S.)-University of Natal, Pietermaritzburg, 2000.

Direct measurement of optical phase is used in a high-density optical disk reader. The increased density is achieved by introducing multiple pit depths to replace the single pit depths of a traditional compact disk. Having four independent pit depths can double the storage capacity of a disk. The multi-level pits are read by direct measurement of the phase difference between two laser spots focused onto the disk surface. Extraction of phase information utilizes the equations of phase shifting interferometry with four shifted fringe patterns created simultaneously by a compact optical head. The system speed is therefore limited by the readout electronics instead of by slow mechanical phase shifters. The resulting system can identify four independent levels as well as the direction of transition from one level to another. The system also has low sensitivity to vibrations and to changes in the fringe contrast and beam intensity.

Anotation Most available studies dedicated to the identity of Roms fail to give a sutisfactory reply to some questions given by the social reality. The reason why lies in the fact that they explore the Romany identity based on culture and culture border studies. This work based on the biographical research is mapping the identity of Roms from the point of view of the participants themselves and their experience. It is focused on factors playing an imortant role when creating and reproducing the Romany identity and when giving meanings to it by its bearers themselves. The work shows that even the absence of any shared culture and social relations in the frame of the broader community it is possible to consider an etnic Romany category since it is is presented as the category not only by the Roms themselves, but by the majority society, which has a real impact on everyday live of each individual who is classified as a Rom.

The primary question to be answered as a result of the research was: Do native English-speaking undergraduate students learn CD-ROM database search skills more effectively through the use of conventional instruction method or by training confined to a written manual self-instructional method? Thirty-seven Oregon State University students were randomly assigned to two groups and participated in the study. The study utilized an experimental pretest-posttest control group design. The length of the study was six weeks. All participants were pre and post-measured using the CD-ROM Database Competency Test which was validated using the Delphi method. The subjects were trained using Wilsondisc and SilverPlatter databases. ANCOVA and t-tests were the main statistics utilized in the analysis. The results of the study were as follows: 1) Subjects in both treatment groups experienced significant test score gains between pretest and posttest; 2) Those subjects which were assigned to the conventional instruction group had significantly higher scores than did subjects assigned to the self-instruction group; 3) Subject gender was determined not to be a factor when differences were considered from test results; 4) Interaction did not play a significant role in influencing the data results; 5) Students rated formal training as being very helpful in improving the effectiveness of their CD-ROM database searches. The major conclusion drawn from the study was that the native English-speaking students at Oregon State University learned CD-ROM searching skills more effectively through the conventional instruction method than those students who were trained by self-instruction. The results of the study substantiated the need to undertake further efforts to improve the efficiency of learning CD-ROM access instructional methods in higher educational settings. / Graduation date: 1994

The hypoxic area in the Gulf of Mexico is the second largest in the world, which has received extensive scientific study and management interest. Previous modeling studies have concluded that the increased hypoxic area in the Gulf of Mexico was caused by the increased anthropogenic nitrogen loading of the Mississippi River; however, the nitrogen-area relationship is complicated by many other factors, such as wind, river discharge, and the ratio of Mississippi to Atchafalaya River flow. These factors are related to large-scale climate variability, and thus will not be affected by regional nitrogen reduction efforts. In the research presented here, both statistical (regression) and numerical models are used to study the influence of anthropogenic and climate factors on the hypoxic area variability in the Gulf of Mexico. The numerical model is a three-dimensional, coupled hydrological-biogeochemical model (ROMS-Fennel). Results include: (1) the west wind duration during the summer explain 55% of the hypoxic area variability since 1993. Combined wind duration and nitrogen loading explain over 70% of the variability, and combined wind duration and river discharge explain over 85% of the variability. (2) The numerical model captures the temporal variability, but overestimates the bottom oxygen concentrations. The model shows that the simulated hypoxic area is in agreement with the observations from the year 1991, as long as hypoxia is defined as oxygen concentrations below 3 mg/L rather than below 2 mg/L. (3) The first three modes from an Empirical Orthogonal Function (EOF) analysis of the numerical model output results explain 62%, 8.1% and 4.9% of the variability of the hypoxic area. The Principle Component time series is cross-correlated with wind, dissolved inorganic nitrogen concentration and river discharge. (4) Scenario experiments with the same nitrogen loading, but different duration of upwelling favorable wind, indicate that the upwelling favorable wind is important for hypoxic area development. However, a long duration of upwelling wind decreases the area. (5) Scenario experiments with the same nitrogen loading, but different discharges, indicate that increasing river discharge by 50% increases the area by 42%. Additionally, scenario experiments with the same river discharge, but different nitrogen concentrations, indicate that reducing the nitrogen concentration by 50% decreases the area by 75%. (6) Scenario experiments with the same nitrogen loading, but different flow diver- sions, indicate that if the Atchafalaya River discharges increased to 66.7%, the total hypoxic area increases the hypoxic area by 30%, and most of the hypoxic area moved from east to west Louisiana shelf. Additionally, if the Atchafalaya River discharge decreased to zero, the total hypoxic area increases by 13%. (7) Scenario experiments with the same nitrogen loading, but different nitrogen forms, indicate that if all the nitrogen was in the inorganic forms, the hypoxic area increases by 15%. These results have multiple implications for understanding the mechanisms that control the oxygen dynamics, reevaluating management strategies, and improving the observational methods.

Thesis (Ph. D.)--University of North Texas, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 177-183).