The sharing of needles among injection drug users (IDUs) is a common route of Human Immunodeficiency Virus and Hepatitis C Virus transmission. Through the increased utilization of social network analysis, researchers have been able to examine how the interpersonal relationships of IDUs affect injection risk behaviour. This study involves a secondary analysis of data from a cross-sectional study of 156 IDUs from Winnipeg, Manitoba titled “Social Network Analysis of Injection Drug Users”. Multiple logistic regression analysis was used to assess the individual and the social network characteristics associated with needle sharing among the IDUs. Generalized Estimating Equations analysis was used to determine the injecting dyad characteristics which influence needle sharing behaviour between the IDUs and their injection drug using network members. The results revealed five key thematic findings that were significantly associated with needle sharing: (1) types of drug use, (2) socio-demographic status, (3) injecting in semi-public locations, (4) intimacy, and (5) social influence. The findings from this study suggest that comprehensive prevention approaches that target individuals and their network relationships may be necessary for sustainable reductions in needle sharing among IDUs.

The main objective of this study is to determine main activity locations and correlation between different artifact types in an archaeological site with geographical information systems (GIS) and spatial data analyses. Knidian amphora workshops in Dat&ccedil / a peninsula are studied in order to apply GIS and spatial statistical techniques. GIS capabilities are coupled with some spatial statistical software and spatial data analysis steps are followed. Both point and area datasets are examined for the effective analysis of the same set of spatial phenomena. Visualizing the artifact distribution with the help of GIS tools enables proposing hypotheses about the study area. In exploration part of the study, those assumptions are tested and developed with the help of explorative methods and GIS. The results are discussed and assessed in terms of archaeological framework. Finally the results are compared with the archeo-geophysical anomalies and excavation results.

In this study, regularly measured long-term leachate data from Bursa Municipal Solid Waste Landfill (MSWL) were analyzed using conventional statistical, time series and factor analyses to investigate in detail the temporal variability of leachate quality and quantity, trend, randomness, seasonality and the auto- and cross- correlations of leachate pollutants. Evaluating the results of data analyses, leachate management recommendations, including sampling strategies in monitoring programs and treatment alternatives for old and fresh leachates, were developed. Statistically analyzed leachate parameters included BOD, COD, pH, SS, electrical conductivity, total CrO4, Cr6+, Fe, Cu, Zn, Pb, Cd, CN-, Cl, F, total P, NH4-N, total N, SO4, S2-, total alkalinity and leachate flow rate. Results indicated that the majority of pollutant concentrations varied in large ranges. Leachate parameters usually showed non-normal distributions and high variability in the closed T Valley compared to the open Main Valley. The majority of leachate parameters was autocorrelated and had statistically significant correlations amongst themselves. Factor analysis showed that different inter-relationships were present between leachate parameters for closed and open valleys. The sampling frequency and the number of leachate parameters need to be measured were determined to be higher for open landfills than for closed landfills. It was recommended that leachates, having high organic strength, in open landfill be treated using biological and physical/chemical processes. However, after the closure of the landfill, physical/chemical processes were recommended for leachate treatment, as it gradually completes transition from fresh to old leachate.

According to a recent exascale roadmap report, analysis will be the limiting factor in gaining insight from exascale data. Analysis problems that must operate on the full range of a dataset are among the most difficult. Some of the primary challenges in this regard come from disk access, data managment, and programmability of analysis tasks on exascale architectures. In this dissertation, I have provided an architectural approach that simplifies and scales data analysis on supercomputing architectures while masking parallel intricacies to the user. My architecture has three primary general contributions: 1) a novel design pattern and implmentation for reading multi-file and variable datasets, 2) the integration of querying and sorting as a way to simplify data-parallel analysis tasks, and 3) a new parallel programming model and system for efficiently scaling domain-traversal tasks. The design of my architecture has allowed studies in several application areas that were not previously possible. Some of these include large-scale satellite data and ocean flow analysis. The major driving example is of internal-model variability assessments of flow behavior in the GEOS-5 atmospheric modeling dataset. This application issued over 40 million particle traces for model comparison (the largest parallel flow tracing experiment to date), and my system was able to scale execution up to 65,536 processes on an IBM BlueGene/P system.

There have been many attempts to use mathematical method in order to characterize shale gas/oil reservoirs with multi-transverse hydraulic fractures horizontal well. Many authors have tried to come up with a suitable and practical mathematical model. To analyze the production data of a shale reservoir correctly, an understanding and choosing the proper mathematical model is required. Therefore, three models (the homogeneous linear flow model, the transient linear dual porosity model, and the fully transient linear triple porosity model) will be studied and compared to provide correct interpretation guidelines for these models. The analytical solutions and interpretation guidelines are developed in this work to interpret the production data of shale reservoirs effectively. Verification and derivation of asymptotic and associated equations from the Laplace space for dual porosity and triple porosity models are performed in order to generate analysis equations. Theories and practical applications of the three models (the homogeneous linear flow model, the dual porosity model, and the triple porosity model) are presented. A simplified triple porosity model with practical analytical solutions is proposed in order to reduce its complexity. This research provides the interpretation guidelines with various analysis equations for different flow periods or different physical properties. From theoretical and field examples of interpretation, the possible errors are presented. Finally, the three models are compared in a production analysis with the assumption of infinite conductivity of hydraulic fractures.

Frequently a discrepancy is found between the stimulated shale volume (SSV) estimated from production data and the SSV expected from injected water and proppant volume. One possible explanation is the presence of a fracture network, often termed fracture complexity, that may have been opened or reopened during the hydraulic fracturing operation. The main objective of this work is to investigate the role of fracture complexity in resolving the apparent SSV discrepancy and to illustrate whether the presence of reopened natural fracture network can be observed in pressure and production data of shale gas wells producing from two shale formations with different well and reservoir properties. Homogeneous, dual porosity and triple porosity models are investigated. Sensitivity runs based on typical parameters of the Barnett and the Horn River shale are performed. Then the field data from the two shales are matched. Homogeneous models for the two shale formations indicate effective infinite conductivity fractures in the Barnett well and only moderate conductivity fractures in the Horn River shale. Dual porosity models can support effectively infinite conductivity fractures in both shale formations. Dual porosity models indicate that the behavior of the Barnett and Horn River shale formations are different. Even though both shales exhibit apparent bilinear flow behavior the flow behaviors during this trend are different. Evidence of this difference comes from comparing the storativity ratio observed in each case to the storativity ratio estimated from injected fluid volumes during hydraulic fracturing. In the Barnett shale case similar storativity ratios suggest fracture complexity can account for the dual porosity behavior. In the Horn River case, the model based storativity ratio is too large to represent only fluids from hydraulic fracturing and suggests presence of existing shale formation microfractures.

There are many issues involved in implementing Information and Communications Technology (ICT) projects in general, and infrastructure (ICT/I) projects in particular. Failures are still common despite advances in project management tools, and increased ICT sophistication. Executive sponsorship and support is acknowledged to make a difference to the success or failure of these kinds of projects. Little has been written on the views of non-ICT executives about the issues they have with ICT/I projects, which have particular challenges because of their highly technical nature. This research sought to develop a theory not only about what the issues are, from the non-ICT executive perspective, but also how these issues appear in, and may affect the outcomes of, such projects. An interpretive study using single units of analysis within multiple cases, to build an inductively derived theory, was the approach chosen for this research. An adapted grounded theory analysis, following the original Glaser and Strauss (1967) philosophy, was used to analyse data extracted from interviews with fifteen chief executives or equivalents. Three themes arose out of this process: Executive Perceptions of ICT/I; Strategic Alignment of ICT/I projects;ICT/I Project Outcomes The themes had quite strong connections between them. Jargon Barriers between ICT staff and these executives, affected the executives perceptions of ICT/I and were strong contributing factors for a poor strategic alignment between ICT/I projects and business goals. The poor alignment was primarily caused as a result of low levels of executive engagement with these projects, because they couldn’t understand the “techno-speak” of their ICT people. The consequence was consistently low satisfaction with ICT/I project life cycle outcomes. There was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. there was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. The substantive theory developed from this work is that: Jargon barriers created by ICT staff generate poor relationships between ICT staff and their executives, which in turn can cause low levels of executive engagement with their infrastructure projects, and consequently affect executive perceptions about the outcomes of these projects.

There are many issues involved in implementing Information and Communications Technology (ICT) projects in general, and infrastructure (ICT/I) projects in particular. Failures are still common despite advances in project management tools, and increased ICT sophistication. Executive sponsorship and support is acknowledged to make a difference to the success or failure of these kinds of projects. Little has been written on the views of non-ICT executives about the issues they have with ICT/I projects, which have particular challenges because of their highly technical nature. This research sought to develop a theory not only about what the issues are, from the non-ICT executive perspective, but also how these issues appear in, and may affect the outcomes of, such projects. An interpretive study using single units of analysis within multiple cases, to build an inductively derived theory, was the approach chosen for this research. An adapted grounded theory analysis, following the original Glaser and Strauss (1967) philosophy, was used to analyse data extracted from interviews with fifteen chief executives or equivalents. Three themes arose out of this process: Executive Perceptions of ICT/I; Strategic Alignment of ICT/I projects;ICT/I Project Outcomes The themes had quite strong connections between them. Jargon Barriers between ICT staff and these executives, affected the executives perceptions of ICT/I and were strong contributing factors for a poor strategic alignment between ICT/I projects and business goals. The poor alignment was primarily caused as a result of low levels of executive engagement with these projects, because they couldn’t understand the “techno-speak” of their ICT people. The consequence was consistently low satisfaction with ICT/I project life cycle outcomes. There was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. there was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. The substantive theory developed from this work is that: Jargon barriers created by ICT staff generate poor relationships between ICT staff and their executives, which in turn can cause low levels of executive engagement with their infrastructure projects, and consequently affect executive perceptions about the outcomes of these projects.

There are many issues involved in implementing Information and Communications Technology (ICT) projects in general, and infrastructure (ICT/I) projects in particular. Failures are still common despite advances in project management tools, and increased ICT sophistication. Executive sponsorship and support is acknowledged to make a difference to the success or failure of these kinds of projects. Little has been written on the views of non-ICT executives about the issues they have with ICT/I projects, which have particular challenges because of their highly technical nature. This research sought to develop a theory not only about what the issues are, from the non-ICT executive perspective, but also how these issues appear in, and may affect the outcomes of, such projects. An interpretive study using single units of analysis within multiple cases, to build an inductively derived theory, was the approach chosen for this research. An adapted grounded theory analysis, following the original Glaser and Strauss (1967) philosophy, was used to analyse data extracted from interviews with fifteen chief executives or equivalents. Three themes arose out of this process: Executive Perceptions of ICT/I; Strategic Alignment of ICT/I projects;ICT/I Project Outcomes The themes had quite strong connections between them. Jargon Barriers between ICT staff and these executives, affected the executives perceptions of ICT/I and were strong contributing factors for a poor strategic alignment between ICT/I projects and business goals. The poor alignment was primarily caused as a result of low levels of executive engagement with these projects, because they couldn’t understand the “techno-speak” of their ICT people. The consequence was consistently low satisfaction with ICT/I project life cycle outcomes. There was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. there was a very real difference between the satisfaction levels of executives who had made definite efforts to overcome, or deal with, the ICT/I jargon barriers, and those who hadn’t. The substantive theory developed from this work is that: Jargon barriers created by ICT staff generate poor relationships between ICT staff and their executives, which in turn can cause low levels of executive engagement with their infrastructure projects, and consequently affect executive perceptions about the outcomes of these projects.

Computer-based information systems (IS) play an increasingly pervasive and important role in contemporary organisations. Despite decades of continuing research and the development of an extensive prescriptive literature, IS development projects continue to be problematic, with many failing or being seriously challenged. In addition, the IS development environment has changed significantly in recent years, with rapid advances or shifts in technology, increasing devolution of IS responsibility and expenditure to user groups, high levels of packaged software acquisition and customisation, greater outsourcing of IS development, and an increasing emphasis on enterprise-wide and inter-organisational IS. In many cases these changes are interrelated and involve more flexible, ad hoc or non-traditional development approaches. Combined with the fact that at the same time IS have become increasingly sophisticated and integrated, the potential for unpredictable or unintended consequences has also increased. Together, the continued problematic nature of many IS projects and the changing IS development environment, suggest that there is an ongoing need for a fuller understanding of IS development processes and practices. Given the limitations of factor-based, prescriptive studies, an understanding of how contemporary IS development is enacted needs to be grounded in and built upon the cumulative body of research that attempts to understand the complexity and dynamic nature of IS development. Accordingly, this study uses a conceptualisation of IS development as a process in which an IS emerges from a dynamic and interactive relationship between the technology, its social and organisational context, and the negotiated actions of various individuals and groups. The thesis presents the results of an extensive empirical investigation into contemporary ARE development practices based on data collected from New Zealand. The study uses a range of research methods and ultimately develops a sociotechnical process model of IS development as situated action. Following Walsham’s (1993) emphasis on the content, context and process of IS-related organisational change, the methods used in this study are three-fold. First, an extensive literature review is undertaken to provide a comprehensive synthesis of contemporary empirical knowledge about the content of IS development. Second, a survey is used to collect contextual data about IS development and acquisition practices in New Zealand. Finally, these both support an in-depth longitudinal case study of the IS development process in an organisational setting. The literature review synthesises the results of recent empirical studies of the various influences that shape IS development, using a classificatory framework based around actors, project content, IS development processes, and context. The review shows that, while a number of traditional factors influencing IS development continue to be relevant, other factors have emerged as important as a result of changes to the IS development environment and to IS development practice. In particular, increasing recognition within the IS literature has been given to the relative importance of people and process and of the organisational and environmental context in which IS development takes place. The results of the literature review inform the design of a survey instrument intended to provide an updated assessment of IS development and acquisition practices in New Zealand organisations. A Web-based survey was administered to a sample of senior IS managers in 460 public and private sector organisations with 200 or more FTEs. Based on the 106 usable responses, the results of the survey confirm the ongoing relevance of a number of traditional factors identified in the IS literature as facilitating or inhibiting IS development. However, a number of factors were identified as emerging or increasing in relevance in light of changes in the IS development environment. While the survey provides a useful description of contemporary IS development and acquisition practice in New Zealand, it does not enable a detailed understanding of IS development in action. To address this, an IS project in a large New Zealand organisation was followed in action for over two years. The project involved the development of a sophisticated financial database model using a purchased commercial software package and external consultants. As such, it provides a useful exemplar of development in a contemporary IS environment. The case study illustrates how a seemingly small, well-defined project experienced delays and difficulties as might be expected in larger, more complex projects. It offers insights into the significance of external actors, the importance of full stakeholder participation, the influence of initial characterisations of the nature of the project, and the observance of project management processes. Consideration of the project outcome reveals its multi-dimensional, subjective and temporal nature. A process approach (Markus & Robey, 1988) is employed to structure the analysis of the case study. A combination of temporal bracketing, narrative analysis and visual representation is used to analyse the sequence of social action and organisational processes involved in the project and to develop a process explanation of how and why the particular project outcome in this case study developed over time. Underpinning and informing this analysis is the construction and utilisation of a model of IS development as a situated, sociotechnical process. Drawing on theoretical concepts from structuration theory and the sociology of technology, the model considers the situated actions and practices of various individuals and groups involved in IS development, the ways in which these are enacted within different contextual elements, and the role of existing and new technological artefacts in this process. IS development is characterised as iterative and emergent, with change occurring dynamically from a trajectory of situated interactions (in which meanings and actions are negotiated) and intended and unintended consequences. As a whole, this PhD highlights the changing nature of the IS development environment and the way a complex ensemble of ‘factors’ interact to influence IS project outcomes. Common themes emerge around the importance of people and process, and the context in which IS development takes place, while at the same time explicitly including a consideration of technology in the analysis.