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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.
81

Single electron transfer in reactions involving alkyl halides with nucleophiles

Pham, Tung Ngoc 05 1900 (has links)
No description available.
82

The mobility and diffusion of potassium ions in gases

James, David Randolph 05 1900 (has links)
No description available.
83

Drift tube measurements of mobilities and longitudinal diffusion coefficients of ions in gases

Chelf, Roger Dale 12 1900 (has links)
No description available.
84

Mobility and Spatial-Temporal Traffic Prediction In Wireless Networks Using Markov Renewal Theory

Abu Ghazaleh, Haitham 12 April 2010 (has links)
An understanding of network traffic behavior is essential in the evolution of today's wireless networks, and thus leads to a more efficient planning and management of the network's scarce bandwidth resources. Prior reservation of radio resources at the future locations of a user's mobile travel path can assist with optimizing the allocation of the network's limited resources. Such actions are intended to support the network with sustaining a desirable Quality-of-Service (QoS) level. To help ensure the availability of the network services to its users at anywhere and anytime, there is the need to predict when and where a user will demand any network usage. In this thesis, the mobility behavior of the wireless users are modeled as a Markov renewal process for predicting the likelihoods of the next-cell transition. The model also includes anticipating the duration between the transitions for an arbitrary user in a wireless network. The proposed prediction technique is further extended to compute the likelihoods of a user being in a particular state after $N$ transitions. This technique can also be applied for estimating the future spatial-temporal traffic load and activity at each location in a network's coverage area. The proposed prediction method is evaluated using some real traffic data to illustrate how it can lead to a significant improvement over some of the conventional methods. The work considers both the cases of mobile users with homogeneous applications (e.g. voice calls) and data connectivity with varying data loads being transferred between the different locations.
85

Segment and ion mobiltiy in polydimethylsiloxanes

Companik, James Edward 08 1900 (has links)
No description available.
86

Theoretical studies of submicron gate length high electron mobility transistors

Park, Duke H. 12 1900 (has links)
No description available.
87

Social mobility in the life cycle of some women clerical workers

Sanderson, K. January 1988 (has links)
No description available.
88

Factors related to teacher mobility in schools of the Northwest Territories and arctic Quebec, 1971-72

1972 December 1900 (has links)
This study was designed to identify factors related to the mobility of teachers in the Northwest Territories and Arctic Quebec, and to explore the relationships among dissatisfaction factors, demographic characteristics of teachers, and mobility. To obtain the data, the Teacher Mobility Questionnaire was constructed and mailed to northern teachers and to some teachers who had left the north in the past two years. The questionnaire consisted of items suggested by the literature on teacher mobility and its causes, as well as items considered appropriate from the author's previous experience in northern Canada. The study sample consisted of 32 former northern teachers and 238 teachers employed in schools of the Northwest Territories and Arctic Quebec at the time of the study. Totals represented a 36 per cent return of completed, acceptable questionnaires. The major areas of study were: a description of northern teachers on the basis of demographic characteristics; an examination of the relationships among demographic variables and mobility; identification of factors related to teacher dissatisfaction; exploration of the relationships among dissatisfaction factors and mobility; and the suggestion of the existence of "unique" northern mobility factors. Statistical procedures used to test hypotheses included correlation coefficients techniques; one-way analyses of variance; and Newman-Keuls comparisons between ordered means. It was found that in comparison to teachers of the four western provinces, those in the Northwest Territories were more likely to be: younger, males, married, originally from Saskatchewan or Ontario; holders of degrees (elementary teachers); at higher salary levels, and more mobile. Over 10 years, the general character of the northern teaching staff showed a trend towards a higher proportion of older, married men with longer training, and employed at higher salaries. The two variables which showed no appreciable change were the length of pre- northern experience, and length of tenure in northern teaching. Both fluctuated between a median of one and two years between 1960 and 1970. Median years of northern experience of teachers in the study was 2.1 years. It was found that the only demographic variables significantly related to mobility were: age, salary, position, and location of school. Although such characteristics as sex, marital status, and previous experience showed some degree of relationship to mobility, they failed to be significant factors. Items from the questionnaire were classified into six dissatisfaction factors. The factors and mean dissatisfaction score for each were: Personal and Economic, 3.001; Working Conditions, 3.200; Recruitment and Orientation, 3.142; Organizational Relationships, 3.159; Adminis tration, 3.284; Achievement, 3.612. Total mean dissatisfaction score was 3.295. Responses were on a five-point scale from (1) dissatisfaction, (2) to satisfaction. Means indicated that respondents in the study expressed more satisfaction than dissatisfaction with those factors investigated. Analysis of the relationship of dissatisfaction to demographic characteristics and mobility found that: females were more dissatisfied than males; younger teachers with fewer years in the north were more dissatisfied than slightly older teachers; primary teachers were more dissatisfied than principals, vice-principals and high school teachers; low salaried teachers were more dissatisfied than higher salaried teachers. In general, the non-mobiles appeared to be less dissatisfied than those who had left the north or intended to do so at the end of the year. It was obvious, however, from the low level of significance found in the analyses performed that dissatisfaction factors as used in this study were not the major reason for teacher mobility in the Northwest Territories and Arctic Quebec. The study was able to suggest such "unique" northern mobility factors as: lack of access to universities; the feeling of impermanence inherent in the northern living situation; isolation from social and cultural life of the south; intentions of being itinerant; difficulties of relating to culturally different pupils and community members. This study indicated a need for further examination of northern teacher mobility with a focus on those factors unique to the northern teaching and living situation.
89

HOMEOWNERSHIP, GEOGRAPHIC MOBILITY AND MORTGAGE STRUCTURE

Mnasri, Ayman 25 June 2014 (has links)
This thesis studies the impact of geographic mobility on the decision of a household to whether to buy or to rent a house, and sheds light on the efficiency of mortgage default prevention policies. The first chapter provides an introduction and an overview of the ongoing policy debates on homeownership and mortgage terms. In the second and third chapters, I study the housing tenure decision in the context of a life cycle model with uninsurable individual income risk, plausibly calibrated to match key features of the U.S. housing market. I find that the relatively low ownership rate of young households is mainly explained by their high geographic mobility. Downpayment constraints have minor quantitative implications on ownership rates, except for old households. I also find that idiosyncratic earnings uncertainty has a significant impact on ownership rates. Based on these results, I argue that the long term increase in ownership rates observed over the period 1993-2009 was not necessarily due to mortgage market innovations and the relaxation of downpayment requirements, as is often argued. Instead, it was simply an implication of U.S. demographic evolution, most notably the decline in interstate migration and, less importantly, population aging. Finally, in Chapter 4, I study the impact of the relaxation of downpayment requirement on homeownership and default risk. Given its quantitative success in matching the U.S. homeownership curve, my model represents a reasonable benchmark to asses the efficiency of mortgage default prevention policies. I find that both income and mobility are the main trigger factors for default decisions. In fact, households with a higher mobility (ie. young households) rate are more likely to default. According to the welfare analysis, I suggest that policymakers include a minimum downpayment requirement of 9.5% in the new definition of the Qualified Residential Mortgage. This number should, however, be viewed with some caution, since I focus on a steady state economy, in which house prices are constant. In fact, the house price represents an important factor influencing the default rate. Potentially, the optimal minimum downpayment requirement should be set at higher value than 9.5%. / Thesis (Ph.D, Economics) -- Queen's University, 2014-06-24 19:58:17.324
90

Mobility and Spatial-Temporal Traffic Prediction In Wireless Networks Using Markov Renewal Theory

Abu Ghazaleh, Haitham 12 April 2010 (has links)
An understanding of network traffic behavior is essential in the evolution of today's wireless networks, and thus leads to a more efficient planning and management of the network's scarce bandwidth resources. Prior reservation of radio resources at the future locations of a user's mobile travel path can assist with optimizing the allocation of the network's limited resources. Such actions are intended to support the network with sustaining a desirable Quality-of-Service (QoS) level. To help ensure the availability of the network services to its users at anywhere and anytime, there is the need to predict when and where a user will demand any network usage. In this thesis, the mobility behavior of the wireless users are modeled as a Markov renewal process for predicting the likelihoods of the next-cell transition. The model also includes anticipating the duration between the transitions for an arbitrary user in a wireless network. The proposed prediction technique is further extended to compute the likelihoods of a user being in a particular state after $N$ transitions. This technique can also be applied for estimating the future spatial-temporal traffic load and activity at each location in a network's coverage area. The proposed prediction method is evaluated using some real traffic data to illustrate how it can lead to a significant improvement over some of the conventional methods. The work considers both the cases of mobile users with homogeneous applications (e.g. voice calls) and data connectivity with varying data loads being transferred between the different locations.

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