Infrastructure Engineering - Research Publications

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    Assessment of error in digital vector data using fractal geometry
    DUCKHAM, MATT ; Drummond, Jane (Taylor & Francis, 2000)
    This paper presents a new method for assessment of error in digital vector geographic data, where the features represented can be modelled closely by fractal geometry. Using example hydrological data from Ordnance Survey of Great Britain maps at a range of scales, a resolution smaller than which the digital representation of the feature does not exhibit fractal characteristics can be calculated. It is proposed that this resolution reflects the minimum ground resolution of the map, which in turn can be related to the source map scale.
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    Spatial data quality capture through inductive learning
    DUCKHAM, MATT ; Drummond, Jane ; Forrest, David (Springer Verlag (Germany), 2000)
    The relatively weak uptake of spatial error handling capabilities by commercial GIS companies and users can in part be attributed to the relatively low availability and high costs of spatial data quality information. Based on the well established artificial intelligence technique of induction, this paper charts the development of an automated quality capture tool. By learning from example, the tool makes very efficient use of scarce spatial data quality information, so helping to minimise the cost and maximise availability of data quality. The example application of the tool to a telecommunications legacy data capture project indicates the practicality and potential value of the approach.
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    A formal approach to imperfection in geographic information
    DUCKHAM, 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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    An algebraic approach to automated information fusion
    DUCKHAM, 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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    Monitoring qualitative spatiotemporal change for geosensor networks
    Worboys, 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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    Commonsense notions of proximity and direction
    WORBOYS, 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.