Theses and Dissertations from UMD
Permanent URI for this communityhttp://hdl.handle.net/1903/2
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Exploring the Geography of Routine Activity Theory: A Spatio-Temporal Test Using Street Robbery(2006-07-10) Groff, Elizabeth; Dubayah, Ralph; Weisburd, David; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Many social phenomena have a spatio-temporal dimension and involve dynamic decisions made by individuals. Investigations focusing on the spatio-temporal dimensions of human behavior have received a great deal of theoretical attention; however, empirical testing of these theories has been handicapped by a lack of micro-level data and modeling tools that can capture the dynamic interactions of individuals and the context in which they occur. This research presents a methodology for evaluating theory through the implementation of a simulation model; the assumptions of the theory are operationalized in a model, a series of experiments are run, and the outcomes are analyzed to discover if they match what the theory would predict. Specifically, the concepts of routine activity theory (RAT) (Cohen and Felson, 1979) are formalized in a computational laboratory representing Seattle, Washington. The computational environment for implementation, Agent Analyst, merges agent-based modeling (ABM) software with geographic information systems (GIS). A strategy for developing activity spaces is implemented and demonstrates how agents can move along existing street networks, and land use patterns can be used to create representational activity spaces. Three versions of a model of street robbery are developed; each version implements a different level of constraints on agent's routine activities. In one version (Simple), individuals are either at home or not at home. In another, individuals follow a temporal schedule (Temporal). Last, individual's schedules are both temporally and spatially constrained (Activity Space). A series of experiments are conducted which compare the incidence and spatial pattern of street robbery events from each version. The results of the experiments provide strong evidence of the important role routine activities play in street robbery events. The addition of temporal and spatio-temporal schedule constraints reduces the incidence and changes the pattern of street robberies. Support for routine activity theory's premise, as time spent away from home increases street robbery will increase, is found in the Simple and Temporal, but not the Activity Space version of the model.Item DISCERNING Intra-Metropolitan Patterns of Producer Service Establishment Location using Geographic Information Systems(2005-11-28) Lindsay, Francis; Geores, Martha; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The research presented in this dissertation explores the spatial distribution of producer service establishments in the Washington DC area for 1997. Producer services are a distinct and important segment of the US industrial economy. These businesses provide the intermediary goods and services that are used as inputs for many other industrial sectors. Producer service employment and sales have grown substantially during the 1990s in relation to other portions of the overall US economy, surpassing growth in most sectors including other types of services. The majority of producer service research tends to focus on these services at the national scale or comparative studies of whole metropolitan areas. This work presents the findings for two complementary producer service research problems pertinent to intra-metropolitan spatial scale research, the contribution of face-to-face interaction to the spatial concentration of these services using sales between particular producer services, and the entropy (or diversity) of services within postal code areas and how this measure correlates to the presence or absence of particular producer services. The findings indicate that there is empirical evidence of a relationship between the strength of intra-sector trade and the degree of spatial concentration of producer service establishments. This analysis also demonstrates that some producer service sectors known to have weak trade relations to other producer services do locate in areas with a lower diversity of services. The results of this research add to a growing body of research and theory that centers on interpreting the role of producer services in shaping metropolitan economies. The spatial component of producer service establishment location in research is often neglected entirely or is superficially referenced. This geographic research provides the spatial dimension of producer service activities occurring at very fine scales within a metropolitan spatial economy. The results are only applicable to the study area but the methodology is useful and offers a potential for broader utility in producer service research endeavors.