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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

FHBS calculation of ionized electron angular and energy distribution following the p+H collision at 20 keV

Fu, Jun 15 November 2004 (has links)
A Finite Hilbert Basis Set (FHBS) method to calculate the angular and energy distribution of ejected electrons in an ion-atom collision is presented. This method has been applied to the p + H collision at 20 keV impact energy. An interference effect between the exit channels, where electrons are guided out of the collision region by both the residual target proton and the projectile proton, is discovered. Experimental data appears to confirm this result.
32

Fear of fatness, eating attitudes, and anti-fat perspectives: a cross-cultural exploration of Euro-American and Indian university students

Ambwani, Suman 29 August 2005 (has links)
Although recent data suggest the existence of anti-fat attitudes, fear of fatness, and maladaptive eating attitudes among Indian women, few researchers have examined the cross-cultural validity of their instruments before assessing Indian samples. The present study assessed the measurement equivalence of three related measures, the Anti-Fat Attitudes Scale, the Goldfarb Fear of Fat Scale, and the Eating Attitudes Test-26, and tested the invariance of latent means among Indian (n = 226) and Euro-American (n = 211) female college students. Multi-group confirmatory factor analyses using maximum likelihood estimation with robust standard errors demonstrated reasonable measurement equivalence of the instruments across Indian and Euro-American groups. Confidence interval comparisons of latent means suggested that the Indians and Euro-Americans did not differ significantly in levels of fear of fatness or eating attitudes, but there were some group differences in anti-fat attitudes. Structural equation modeling suggested that fear of fatness and anti-fat attitudes predict about 66% of the variance in Indian eating attitudes; however, these results must be interpreted cautiously due to a poorly fitting measurement model. Results of multiple regression analyses suggested that the eating attitudes of the Indian respondents were not significantly predicted by theirsocioeconomic status or degree of Westernization. In conclusion, these data suggest that there are some similarities, but also some important differences, in the eating-related attitudes and behaviors of Euro-American and Indian women.
33

Distributed Cross-layer Monitoring in Wireless Mesh Networks

Panmin, Ye, Yong, January 2009 (has links)
No description available.
34

Synthesis of Aromatic Heterocycles and Carbocycles Through Tandem Palladium-catalyzed Cross-couplings of gem-dihaloolefins

Bryan, Christopher 14 February 2011 (has links)
Our group has developed a strategy for the synthesis of benzofused carbocycles and heterocycles through tandem palladium-catalyzed reactions of gem-dibromoolefins. In these syntheses, one bromide undergoes a Pd-catalyzed cyclization reaction, and the other participates in an orthogonal inter- or intramolecular Pd-catalyzed reaction to functionalize or annulate that ring, respectively. Chapter 1 describes the pairing of an intramolecular C–N bond forming reaction (the Buchwald-Hartwig coupling) with an intramolecular direct arylation for the synthesis of fused indole derivatives. A range of previously unknown heterocycles were synthesized through this method. Chapter 2 describes the synthesis of benzothiophenes through the combination of a Pd-catalyzed C–S coupling with an orthogonal Suzuki, Heck, or Sonogashira reaction. This represents the first example of the incorporation of Pd-catalyzed C–S coupling into a tandem reaction. In Chapter 3, a tandem intramolecular Heck / intermolecular Suzuki reaction is described for the synthesis of methyleneindenes. Studies on this reaction have provided advanced understanding of the mechanism, including how variation of the ligand controls the regioselectivity of the reaction.
35

Synthesis of Aromatic Heterocycles and Carbocycles Through Tandem Palladium-catalyzed Cross-couplings of gem-dihaloolefins

Bryan, Christopher 14 February 2011 (has links)
Our group has developed a strategy for the synthesis of benzofused carbocycles and heterocycles through tandem palladium-catalyzed reactions of gem-dibromoolefins. In these syntheses, one bromide undergoes a Pd-catalyzed cyclization reaction, and the other participates in an orthogonal inter- or intramolecular Pd-catalyzed reaction to functionalize or annulate that ring, respectively. Chapter 1 describes the pairing of an intramolecular C–N bond forming reaction (the Buchwald-Hartwig coupling) with an intramolecular direct arylation for the synthesis of fused indole derivatives. A range of previously unknown heterocycles were synthesized through this method. Chapter 2 describes the synthesis of benzothiophenes through the combination of a Pd-catalyzed C–S coupling with an orthogonal Suzuki, Heck, or Sonogashira reaction. This represents the first example of the incorporation of Pd-catalyzed C–S coupling into a tandem reaction. In Chapter 3, a tandem intramolecular Heck / intermolecular Suzuki reaction is described for the synthesis of methyleneindenes. Studies on this reaction have provided advanced understanding of the mechanism, including how variation of the ligand controls the regioselectivity of the reaction.
36

Impact of Culture on Mobile Phone Purchasing A Comparison between Thai and Swedish Consumers

Wongdatengam, Siraporn, Kruapanichwong, Panjaporn January 2011 (has links)
“Mobile phones as a communication technology fits into culture rather than imposes on a culture” (Xin, 2006).Therefore, the main purpose of this research was to investigate and to understand the impact national culture has on mobile phone buyer behaviour of Thai and Swedish consumers. The research was also conducted to identify whether there was a significant cultural difference of buying behaviour for these two cultures when purchasing mobile phones.  Hofstede’s cultural dimensions (individualism/collectivism and power distance) was addressed in order to examine if culture influences Thai and Swedish consumers when purchasing a mobile phone.  In order to examine the difference between Thai and Swedish consumers, a data analysis was conducted through the SPSS statistical program using an Independent Sample T-test and Pearson Correlations. The questionnaires were distributes to both Thai (70 sets) and Swedish (70sets) students in the University of Malardalen. The findings indicated that there is a significant difference between Thai and Swedish consumers in term of mobile phone purchasing behaviour as far as Hofstede’s cultural dimensions. A major contribution to this study is that it will provide an insight into the differences in culture between Swedish and Thai consumers, the Eastern and Western cultural divide and how culture influences mobile phone purchasing behaviour.   The findings will also assist managers in mobile phone organizations to manage the dynamics of culture through time as well as to enhance their communications and promotional strategies within an overall marketing strategy. Incorporating culture into their overall marketing and communications strategies will enable organizations to meet customer needs and expectations, sustain and increase growth along with market share and to maximize profitability.
37

Determination of Differential Cross Sections from Sliced Fluorescence Image Experiment in the Bulb Environment

Li, Yu-chi 02 July 2010 (has links)
"none"
38

An investigation of the relationship between cultural competence and expatriate job performance

Kim, Kwanghyun 15 May 2009 (has links)
This dissertation investigates whether cultural competence, defined as a person’s ability to interact effectively with others from a different cultural background or in a cross-cultural setting, predicts expatriate adjustment and job performance more effectively than other individual-level predictors such as personality and local language proficiency. Rather than simply focusing on the predictive validity of cultural competence, this study also explores a process model that could explain the link between cultural competence and expatriate job performance by proposing a mediating variable of cross-cultural adjustment. Lastly, in a more integrated way, this study examines how the relationship between expatriate adjustment and job performance may be better understood by two potential moderating variables: conscientiousness and expatriate assignment nature. For testing the proposed hypotheses, expatriates in a Fortune 500 company were invited to participate in a web-based survey. Responses about their international assignment experience were obtained from 338 expatriates located in 43 countries, and their supervisors. A set of multiple regression analyses were conducted and three major findings emerged. First, the analyses confirmed the important role of some individual difference such as conscientiousness and local language proficiency in expatriate assignment effectiveness, consistent with the literature. Second, the results showed the unique roles of some cultural competence dimensions in predicting expatriate adjustment and job performance, beyond the effects of other important individual-level variables. Lastly, the results also demonstrated a process model of the effect of motivational cultural competence on expatriate job performance: motivational cultural competence works through work adjustment to influence expatriate job performance. Taken together, these findings provide more comprehensive knowledge about whether and how certain individual differences are related more effectively to expatriate assignment effectiveness. In practical terms, this research has implications regarding expatriate selection and development, in order to improve the chances of success in international assignments.
39

The impact of misspecifying cross-classified random effects models in cross-sectional and longitudinal multilevel data: a Monte Carlo study

Luo, Wen 15 May 2009 (has links)
Cross-classified random effects models (CCREMs) are used in the analyses of cross-sectional and longitudinal multilevel data that are not strictly hierarchical. Because of the complexity of this technique, many researchers simply ignore the cross-classified structures of their data and use hierarchical linear models. The study simulated crosssectional and longitudinal multilevel data with cross-classified structures and examined the impact of misspecifying CCREMs on parameter and standard error estimates in these data. The dissertation consists of two studies. Study One examines cross-sectional multilevel data and Study Two examines longitudinal multilevel data. In Study One, three-level cross-classified data were generated. Two random factors were crossed at either the top level or the intermediate level. It was found that ignoring a crossed random factor causes the variance of the remaining crossed factor and the adjacent levels to be overestimated. The fixed effects themselves are unbiased; however, the standard errors associated with the fixed effects are biased. When the ignored crossed factor is at the top level, the standard error of the intercept is underestimated whereas the standard error of the regression coefficients associated with the covariate of the intermediate level and the remaining crossed factor are overestimated. When the ignored crossed factor is at the intermediate level, only the standard error of the regression coefficients associated with the covariate of the bottom level is overestimated. In Study Two, longitudinal multilevel data were generated mirroring studies in which students are measured repeatedly and change schools over time. It was found that when the school level is modeled hierarchically above the student level rather than as a crossed factor, part of the variance at the school level is added to the student level, causing underestimation of the school-level variance and overestimation of the studentlevel variance and covariance. The standard errors of the intercept and the regression coefficients associated with the school-level predictors are underestimated, which may cause spurious significance for results. The findings of the dissertation enhanced our understanding of the functioning of CCREMs in both cross-sectional and longitudinal multilevel data. The findings can help researchers to determine when CCREMs should be used and to interpret their results with caution when they misspecify CCREMs.
40

TXSAMC (transport cross sections from applied Monte Carlo): a new tool for generating shielded multigroup cross sections

Hiatt, Matthew Torgerson 02 June 2009 (has links)
This thesis describes a tool called TXSAMC (Transport Cross Sections from Applied Monte Carlo) that produces shielded and homogenized multigroup cross sections for small fast reactor systems. The motivation for this tool comes from a desire to investigate reactor systems that are not characterized well by existing tools. Proper investigation usually requires the use of deterministic codes to characterize the timedependent reactor behavior and to link reactor neutronics codes with thermal-hydraulics and/or other physics codes. Deterministic codes require an accurate set of multigroup cross section libraries. The current process for generating these libraries is time consuming. TXSAMC offers a shorter route for generating these libraries. TXSAMC links three external codes together to create these libraries. The code creates an MCNP (Monte Carlo N-Particle) model of the reactor and calculates the zoneaveraged scalar flux in various tally regions and a core-averaged scalar flux tallied by energy bin. The core-averaged scalar flux provides a weighting function for NJOY. The zone-averaged scalar flux data is used in TRANSX for homogenization and shielding. The code runs NJOY to produce multigroup cross sections that are tabulated by nuclide, temperature and background cross section in MATXS (Material-wise cross section) format. This library is read by TRANSX which, in conjunction with the RZFLUX (Regular Zone-averaged Flux) files, shields the cross sections and homogenizes them. The result is a macroscopic cross section for the cell within the reactor from which the RZFLUX file was written. The cross sections produced by this process have been tested in five different sample problems and have been shown to be reasonably accurate. For reactor cells containing fuel pins, the typical error in the overall fission, nusigf, (n,2n), absorption and total RRD is only a few percent and is often less than one percent. It appears that the error is less for hexagonal lattices than for square lattices. A significant amount of error is associated with threshold reactions like (n,2n) in the sodium coolant. For the square lattice test problems, a reduction in error occurs when smaller tally regions are selected. This reduction was not observed for hexagonal lattice reactors. Overall, the cross sections produced by TXSAMC performed very well.

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