This dissertation begins with proposing a novel street Connectivity Indicator (C.I.) to predict transit performance by identifying the role that street network connectivity plays in influencing the service quality of demand responsive feeder transit services. This new C.I. definition is dependent upon the expected shortest path between any two nodes in the network, includes spatial features with transit demand distribution information and is easy to calculate for any given service area. Subsequently, a methodology to identify and locate critical links within a grid street system for operating feeder transit services is also developed. A 'critical' street link causes the largest change in transit performance due to the link's removal or addition to an existing network. The most important contribution of this section on link criticality is to present a simple closed-form analytical formula in locating the critical link(s) for a grid street network system of 'any' size. Easily computable formulas have been provided and validated by simulation analyses. Another related model is proposed to compute the optimal grid street spacing that would enhance performance of a demand responsive feeder transit system. The model is tested using simulation. Lastly, an analytical model is also developed for estimating optimal service cycle length or headway of a demand responsive feeder transit service designed to serve passengers, especially during peak periods of demand. Simulation analyses over a range of networks have been conducted to validate the new C.I. definition. Results show a desirable monotonic relationship between transit performance and the proposed C.I., whose values are directly proportional and therefore good predictors of the transit performance, outperforming other available indicators, typically used by planners. Further, useful insights indicate a monotonic decrease in link criticality as we depart from the centrally located links to those located at boundaries. Using a real case example from Denver of the Call-n-Ride system operating similar to a demand responsive feeder transit, optimal cycle lengths differed very modestly from those computed using the model. Extensive simulations performed for different sets of feeder service areas and demand densities, further validated the optimal cycle length model.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1996. / Includes bibliographical references (leaves 371-386). / Microfiche. / vii, 386 p. leaves, bound 29 cm

This study explored the experiences of street-involved youth who have received mental health services for symptoms of methamphetamine-induced psychosis. Specifically, the study investigated what factors were perceived by participants to promote and hinder access to mental health services. The researcher interviewed nine street youth at Covenant House, a Vancouver agency serving street-involved youth. Interview data and the researcher's field notes were coded and analyzed within a grounded theory paradigm. Youth discussed formal and informal sources of help and routes to both. Two distinct perspectives to treatment were identified: an addictions perspective and a concurrent disorders perspective. Respondents outlined the typical pathway into methamphetamine use and described barriers and supports for accessing services while undergoing drug-induced psychosis. Significant factors that encouraged access to services were positive relationships with helpers, strong peer supports, and the use of involuntary services when necessary. Identified barriers included fear of being stigmatized, lack of problem awareness, and systemic barriers. The current research proposed a model of access to mental health services that positions outreach and frontline workers as key figures to mediating street youth's access to appropriate services.

Background: Street-involved youth are known to be at a greatly increased risk of HIV and sexually transmitted infections (STIs); however, the role that environmental and structural factors play in driving disease transmission risk among this population has not been thoroughly examined. Methods: The At Risk Youth Study (ARYS) is a prospective cohort of homeless and street-involved youth between the ages of 14 and 26. From September 2005 to October 2006, participants completed a baseline questionnaire which elicited information regarding sexual activity, injection and non-injection drug use, addiction treatment experience, encounters with police and security guards, and health service utilization. Environmental and structural correlates of number of recent sex partners were identified using quasi-Poisson regression. Factors independently associated with consistent condom use were also examined using logistic regression. Results: Among 529 participants, 415 (78.4%) were sexually active during the past six months, of whom 253 (61.0%) reported multiple sex partners and 288 (69.6%) reported inconsistent condom use during this time period. In multivariate logistic regression, homelessness and self-reported structural barriers to accessing health services were inversely associated with consistent condom use. In multivariate analysis, living in a shelter, hostel, or single room occupancy hotel was positively associated with greater numbers of recent sex partners. Structural factors that were associated with number of sex partners included having a warrant or area restriction that affects access to health services, and for males, being accosted by the police. Conclusions: Unstable housing, homelessness, and structural factors related to the criminalization and displacement of street-involved youth were associated with an increased risk of HIV and STI transmission, even after extensive adjustment for sociodemographic and individual level characteristics. These findings suggest that both environmental and structural factors influence the spread of HIV and STIs, and point to the need for environmental-structural interventions to reduce the burden of these diseases among this population.

An urban environment can be abstracted in form of a street network in order to be further analysed structurally. The urban street network can be represented in various ways by taking different principles and constraints into account. Therefore the aim of this work is to investigate human behaviour and communication in emerged urban phenomena, namely traffic flow and wayfinding, by structural characterization of an appropriate representation of an urban street network and modifying the conventional methods. / In order to characterize the depicted urban street network, centrality measure and specifically betweenness centrality is utilized. This analysis is then implemented to characterize the studied urban phenomena with respect to their structural, temporal and dynamic properties. In case of studying only the structural properties of the phenomena such as route description or self localization the conventional betweenness centrality is performed. But in case of studying the dynamic and temporal properties of a phenomenon such as traffic flow a modified version of betweenness centrality is proposed which considers dynamic and temporal aspects of human travel behaviour. / Experiments are designed to test the implementation of the suggested methods in the studied urban phenomena. The results of experiments demonstrate the efficiency of the proposed model in characterization of the studied urban phenomena in this thesis and then mention some of the problems and potential areas for future works.

Thesis (doctoral)--Universität, Mainz, 2004. / Includes bibliographical references (p. [629]-675).

Thesis (M.A.)--University of Delaware, 2008. / Principal faculty advisor: Katherine C. Grier, Winterthur Program in Early American Culture. Includes bibliographical references.

Thesis (MA(Psychology))-University of Pretoria, 2008. / Includes bibliographical references.

Thesis (D. Min.)--New Orleans Baptist Theological Seminary, 1993. / Includes abstract and vita. Includes bibliographical references (leaves 237-250).

Thesis (M.A.) - Carleton University, 2005. / Includes bibliographical references (p. 129-139). Also available in electronic format on the Internet.