NCGIA National Center for Geographic Information and Analysis Integrating Normative Location Models into GIS: Problems and Prospects with the p-median Model
نویسندگان
چکیده
There has been considerable interest in the development of analysis techniques for Geographical Information Systems (GIS). This includes such normative spatial models as vehicle routing models, districting and turfing models for dividing up land into territories for schools, sales/service, and voting, and location models for identifying sites or patterns of sites to provide service accessibility. The GIS system may provide a unique data base for application and analysis. This paper discusses several problems associated with the integration of a normative location model into a GIS. A number of specifics associated with the p-median model are given. These include: demand zone definition, facility site definition, and solution algorithm selection and development. Within the context of selecting a solution process, we show that such a selection is not necessarily an easy one to make. We demonstrate that the best such solution technique may have some potential drawbacks in application. We present the results of several test applications and a glimpse of the pathology of the final solutions. This discussion raises a major, but often ignored, issue involving the application of a location heuristic: namely, how often should we restart a heuristic to help ensure that the best solution found is optimal or near-optimal. We propose and test a dynamic stopping rule that can be used to help ensure that the best solution is identified. The results of this analysis can be of great, practical value in the successful application of location models within a GIS framework.
منابع مشابه
Temporal Relations in Geographic Information
A workshop on temporal relations in Geographic Information Systems (GIS) was held on October 12-13, 1990, at the University of Maine. The meeting was sponsored by the National Center for Geographic Information and Analysis (NCGIA). Seventeen specialists gathered from the fields of Geography, GIS, and Computer Science to discuss users' requirements of temporal GIS and to identify the research is...
متن کاملA Research Agenda for Geographic Information and Analysis
Preface In our original NCGIA proposal to the National Science Foundation (NSF) in 1988, we presented a two-part research plan that responded directly to the solicitation document issued by NSF in late 1987. The first part (subsequently published as NCGIA, 1989) was a discussion of impediments to the successful use of GIS in geographic analysis, together with the research necessary to overcome ...
متن کاملNCGIA National Center for Geographic Information and Analysis A Conceptual Framework for Integrated Metadata Management in Very Large Spatial Databases
A conceptual framework for integrated metadata management in large spatial databases is described. The primary function of this framework is to allow definition, location and control of metalevel information about the underlying database. The framework provides for a set of core metadata components and allows for addition of any auxiliary metadata that the user might want to define. The framewo...
متن کاملNational Center for Geographic Information and Analysis Visual Interfaces to Geometry
This report presents the results of a two-day workshop on "Visual Interfaces to Geometry" which was conducted by Werner Kuhn and Max Egenhofer at ACM's CHI'90 Conference on Human Factors in Computing Systems. From the perspective of the National Center for Geographic Information and Analysis (NCGIA), this workshop provided an opportunity to share and discuss results of NCGIA's Research Initiati...
متن کامل