The popularity of the World Wide Web (WWW) in providing a vast array of information has drawn a large number of users in the past few years. The dramatic increase in the number of Internet users, however, has brought undesirable impacts on users, such as long response time and service unavailability. The utilization of multiple servers can be used to reduce adverse impacts. The challenge is to identify a good resource site to allocate to the user given a group of servers from which to select. In this project, a performance-directed site selection system was developed for a web-based application called AADMLSS (African American Distributed Multiple Learning Styles System). Four different sets of experiments were conducted in this study. In order to evaluate the effectiveness of the test system, two other server selection methods, Load-based and Random-based methods, were implemented for comparative purposes. The experiments were also run during daytime and nighttime to see the impact of network load on the response time. Experimental results indicate that the performance-directed site selection system outperforms the Load-based and Random-based methods consistently. The response time is typically high during daytime and low during nighttime, indicating that the network load has an impact on the response time delivered. The results also show that server performance contributes to the overall response time, and network performance is the more dominating factor in determining a good resource site for the user.

This dissertation studies the antecedents and consequences of the flow experience in online retailing environments. Flow is the enjoyable and engrossing experience that people feel when acting with total involvement. A review of previous studies suggests that applying the notion of flow to understand the online consumer experience is a promising but underdeveloped field with several conceptual and methodological issues. This dissertation attempts to contribute to our understanding of flow in online shopping in three ways. First, a three-part validity study was carried out using different approaches to construct validity and involving two sets of two flow measures: the Flow State Scale (FSS, Jackson and Marsh 1996) and the Internet Flow Scale (IFS). The first study related flow to behavioral criteria in online shopping. The second conducted a traditional construct validity study in which we developed and tested a “nomological network” of relationships between flow measures and other logically-related constructs. This study also included a Multitrait-Multimethod validity study. The third was a factorial validity study of the flow construct. These studies provided evidence of construct validity for flow and suggested that the FSS had advantages over the IFS in terms of validity. Second, this dissertation tested a comprehensive model of flow that included the underlying dimensions of flow, the mediating effects of perceived challenge and skill on flow, and antecedents and consequences of flow. Consequences of flow include perceived usefulness, affective responses to the site, and intentions to revisit and purchase. Overall, results based on data collected by a controlled experiment supported our model, suggesting that flow is a second-order construct and positively related to outcome variables. Thirdly, we studied the effect of Web site complexity on flow. Perceived site complexity was found to effect flow negatively. Investigating the effects of it on inducing flow in online shopping may eventually lead us to guidelines for improving the shopping experience by designing more capable Web sites.

The use of site-specific data can enhance management decisions in the field. Three different uses of site-specific data were evaluated and their outcomes are promising. Historical yield data from yield monitors and height data from the HMAP (plant height mapping) system were used to select representative areas within the field, and areas of average conditions were used as sampling sites for COTMAN, a cotton management expert system. This proved to be effective, with predicted cutout dates and date of peak nodal development similar to the standard COTMAN approach. The HMAP system was combined with historical height data for variable rate application of mepiquat chloride, based on the plant growth rate. The system performance was evaluated, but weather conditions in 2004 did not allow a true evaluation of varying mepiquat chloride. A series of multi-spectral images were normalized utilizing the soil line transformation (SLT) technique and normalized difference vegetation index (NDVI) was calculated from the transformed images, from the raw image and for the true reflectance images. The SLT technique was effective in tracking the change in true reflectance NDVI in some images, but not all. Changes to the soil line extraction program are suggested so that it more effectively determines soil lines.

Available fragile site identification software packages (FSM and FSM3) assume that all chromosomal breaks occur independently. However, under a Mendelian model of inheritance, homozygosity at fragile loci implies pairwise correlation between homologous sites. We construct correlation models for chromosomal breakage data in situations where either partitioned break count totals (per-site single-break and doublebreak totals) are known or only overall break count totals are known. We derive a likelihood ratio test and Neyman’s C( α) test for correlation between homologs when partitioned break count totals are known and outline a likelihood ratio test for correlation using only break count totals. Our simulation studies indicate that the C( α) test using partitioned break count totals outperforms the other two tests for correlation in terms of both power and level. These studies further suggest that the power for detecting correlation is low when only break count totals are reported. Results of the C( α) test for correlation applied to chromosomal breakage data from 14 human subjects indicate that detection of correlation between homologous fragile sites is problematic due to sparseness of breakage data. Simulation studies of the FSM and FSM3 algorithms using parameter values typical for fragile site data demonstrate that neither algorithm is significantly affected by fragile site correlation. Comparison of simulated fragile site misclassification rates in the presence of zero-breakage data supports previous studies (Olmsted 1999) that suggested FSM has lower false-negative rates and FSM3 has lower false-positive rates.

Tissue equivalent proportional counters are frequently used to measure dose and dose equivalent in mixed radiation fields that include neutrons; however, detectors simulating sites 1?m in diameter underestimate the quality factor, Q, for low energy neutrons because the recoil protons do not cross the detectors. Proportional counters simulating different site-sizes can be used to get a better neutron dose equivalent measurement since the range and stopping power of protons generated by neutrons in the tissue-equivalent walls depend on the energy of the primary neutrons. The differences in the spectra measured by different size detectors will provide additional information on the incident neutron energy. Monte Carlo N-particle extended (MCNPX) code was used to simulate neutron transportation in proportional counters of different simulated tissue diameter. These Monte Carlo results were tested using two solid walled tissue equivalent proportional counters, 2mm and 10mm in diameter, simulating tissue volumes 0.1?m and 0.5?m in diameter, housed in a single vacuum chamber. Both detectors are built with 3mm thick tissue equivalent plastic (A-150) walls and propane gas inside for dose measurement. Using these two detectors, the spectra were compared to determine the underestimation of y for large detector, and thereby obtain more information of the incident neutron particles. Based on the MCNPX simulation and experimental results, we can see that the smaller detector produces a larger average lineal energy than the larger detector, which means the larger detector (0.5?m diameter tissue equivalent size) underestimates the Q value for the low energy neutron, therefore underestimates the effective dose. These results confirm the results of the typical analysis of lineal energy as a function of site size.

In the decade of 1990s, many traditional industries of Taiwan, especially those of labor intense type, began to transfer their production lines to off shore sites for their foreign direct investment. Many of them were following their customers¡¦ migrations to China, Vietnam and other Southeast Asian countries based on the need of upgrading their competence through supply chain integration and taking advantages of the abundance in human resource and lower labor cost in these countries. This study applies tanning industry A company as a model which became a multi-national corporate (MNC) by establishing its first tannery in Taiwan during the 1980s, building up its second factory in China in 1998 and then opening its third one in Vietnam for mass production in 2004. Concerning the environmental and water conservation issues, the three tanneries of A company utilize a production process using wet blue instead of salted hides that most tanneries use as raw material to make finished leather as products. In the past few years, the volatility in hide market price, over capacity in the tanning industry worldwide, and customer¡¦s bargaining power increase made a dramatic fall in the margins of tanning industry. Suffering from the low margins, A company is seeking the possibility of vertical integration in raw material supply by investing a beam house tannery with slated hide as raw material to make wet blue for its three tanneries producing finished leather. This study focused on the critical factors in the site selection decision making for A company¡¦s overseas wet blue tannery investment. In this study, the high level management members of A company and selected experts from other tanneries were interviewed with a pretest questionnaire and then an AHP questionnaire on the critical factors in site selection decision making for multinational tanning industry¡¦s overseas vertical integration investment. The answered AHP questionnaires were analyzed with software Expert Choice 2000 for Analytic Hierarchy Process(AHP) analysis. The conclusions of this study based on the AHP analysis results include: 1. The critical factors in site selection decision making for multinational tanning industry¡¦s overseas vertical integration investment: the decisive elements in level two and level three of the AHP model as well as the ranking in priority of all decisive elements. 2. The suggested most favorable site for A company to invest a wet blue tannery for its vertival integration.

This thesis first discusses the ground plane effects of a test site on the antenna factors (AFs) of hybrid antenna (biconical log-periodic dipole array). Meanwhile, the effects of mutual coupling between antenna and its image, and the variation of active phase center are also discussed. From these analyses, a hybrid method, based on the modified SSM (Standard Site Method) and the PCPM (Phase Center and Pattern Matching) applied to the hybrid antenna for NSA (Normalized Site Attenuation) measurement is proposed. By this method, the low geometry- dependent AFs of hybrid antenna can be obtained to produce more reasonable NSA values for a test site. Secondly, this thesis proposes a simple, fast, and accurate method to calibrate the free-space AFs of broadband EMC (Electromagnetic Compatibility) antennas. This method adopts a fixed-height configuration and a MUSIC (MUltiple SIgnal Classification) algorithm. This configuration significantly shortens measurement time and removes height-dependent calibration errors. Meanwhile, the MUSIC algorithm can remove unexpected reflections from the ground plane or any other reflecting objects, by which the free-space AFs can be calculated. In addition, this method can also automatically compensate for the phase center shift, which makes measurement easier and more convenient. To verify this method, the calibrated results are compared with other published standard methods: the mean differences can be as low as 0.25 dB for the LPDA (log-periodic dipole array), 0.42 dB for the hybrid antennas, and 0.36 dB for the horn antennas. Finally, this thesis provides a method of using two equivalent negative inductances from two terminals of three coupled inductors to reduce the parasitic inductances of a typical three-capacitor EMI (Electromagnetic Interference) filter. Theoretical analysis and formula deduction for the design of two equivalent negative inductances are demonstrated. The experimental results show that the insertion losses of a three-capacitor EMI filter at 50 MHz can be reduced by 16.8 dB for the DM (differential-mode) and by 19.2 dB for the CM (common-mode). In Appendix A of this thesis, an extended study of the effect of ground plane on antenna¡¦s radiation is described. A simple V-shape edge-groove design for a finite ground plane can effectively reduce the pattern ripples of a monopole. The optimal design of proposed structure can reduce the peak-to-peak pattern ripples from 26 to 4.5 dB.

<p>The genomes of several organisms have been sequenced and the need for methods to analyse the data is growing. In this project a method is described that tries to identify co-regulated genes. The method identifies transcription factor binding sites, documented in TRANSFAC, in the non-coding regions of genes. The algorithm counts the number of common binding sites and the number of unique binding sites for each pair of genes and decides if the genes are co-regulated. The result of the method is compared with the correlation between the gene expression patterns of the genes. The method is tested on 21 gene pairs from the genome of Saccharomyces cerevisiae. The algorithm first identified binding sites from all organisms. The accuracy of the program was very low in this case. When the algorithm was modified to only identify binding sites found in plants the accuracy was much improved, from 52% to 76% correct predictions.</p>

Dissertation--Archaeology--University of Calgary, 1998. / Bibliogr. p. 291-302.

Texte remanié de: Diss.--Fakultät für Orientalistik und Altertumswissenschaft--Heidelberg--Ruprecht-Karl-Universität, 1987. / Bibliogr. p. 213-234. Index.