- Infrastructure Engineering - Research Publications
Infrastructure Engineering - Research Publications
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ItemA formal approach to imperfection in geographic informationDUCKHAM, MATT ; MASON, KEITH ; Stell, John ; Worboys, Mike (Elsevier, 2001)Traditional computational models of geographic phenomena offer no room for imperfection. Underlying this tradition is the simplifying assumption that reality is certain, crisp, unambiguous, independent of context, and capable of quantitative representation. This paper reports on initial work which explicitly recognises that most geographic information is intrinsically imperfect. Based on an ontology of imperfection the paper explores a formal model of imperfect geographic information using multi-valued logic. The development of Java software able to assist with a geodemographic retail site assessment application is used to illustrate the utility of a formal approach.
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ItemAn algebraic approach to automated information fusionDUCKHAM, MATT ; WORBOYS, MICHAEL (Taylor & Francis, 2005)This paper presents a new technique for information fusion. Unlike most previous work on information fusion, this paper explores the use of instance-level (extensional) information within the fusion process. This paper proposes an algorithm that can be used automatically to infer the schema-level structure necessary for information fusion from instance-level information. The approach is illustrated using the example of geospatial land cover data. The method is then extended to operate under uncertainty, such as in cases where the data is inaccurate or imprecise. The paper describes the implementation of the fusion method within a software prototype. Finally, the paper discusses several key topics for future research, including applications of this work to spatial data mining and the semantic web.
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ItemMonitoring qualitative spatiotemporal change for geosensor networksWorboys, Mike ; DUCKHAM, MATT (Taylor & Francis, 2006)Recent technological advances in geosensor networks demand new models of distributed computation with dynamic spatial information. This paper presents a computational model of spatial change in dynamic regions (such as may be derived from discretizations of continuous fields) founded on embeddings of graphs in orientable surfaces. Continuous change, connectedness, and regularity of dynamic regions are defined and local transition rules are used to constrain region evolution and enable more efficient inference of a region’s state. The model provides a framework for the detection of global high-level events based on local low-level “snapshot” spatiotemporal data. The approach has particular relevance to environmental monitoring with geosensor networks, where technological constraints make the detection of global behavior from local conditions highly advantageous.
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ItemCommonsense notions of proximity and directionWORBOYS, MICHAEL ; DUCKHAM, MATT ; KULIK, LARS (Springer Verlag, 2004)It is desirable that formal theories of qualitative reasoning should be informed by the ways in which humans conceptualize the spaces in which they live. The work described in this paper uses data provided in experiments with human subjects to derive some regularities in such conceptualizations. The data concerns human conceptualization of proximity and direction within a university campus. The results are analyzed using several approaches. In particular, the relationship between geometric and human conceptual models of the space is explored; the structure and regularities of combinations of proximity and direction relations are examined; and the issue of granularity in vague spatial relations is considered. Overall, the results show that while individual differences between humans are important, there are striking regularities in the population’s notions of distance and direction in the space. The paper concentrates primarily on the formal foundations of commonsense notions of proximity and direction, but also identifies links to more applied domains, such as mobile and location-aware navigation systems.