Infrastructure Engineering - Research Publications
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ItemAdverse possession as repair mechanism: recent developments and further reflections(Department of Geomatics, University of Melbourne, 2007)Recent developments regarding the law of part parcel adverse possession of registered title ("Torrens") land in England, Nova Scotia, New South Wales and Queensland are discussed with particular regard to disputed boundary location.
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ItemAutomated geographic information fusion and ontology alignment(Springer, Berlin, 2007)
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ItemComputational structure in three-valued nearness relations(Springer, 2001)The development of cognitively plausible models of humanspatial reasoning may ultimately result in computational systems thatare better equipped to meet human needs. This paper explores how humansubjects perceive the qualitative spatial relation nearness within anenvironmental space. Based on experimental data, a three-valued nearnessrelation is analysed in two stages. First, the results are analysedwith special reference to the existence of subsets of candidate landmarkplaces, from which nearness relations between other places may be partiallyinferred. Second, the desirable properties of such landmark setsare considered and some of their formal properties are presented. Theseproperties are then considered in the light of the data furnished by theexperiment. The paper concludes with a discussion of the signicance ofthe analyses and the scope for further work in this area.
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Item"Simplest" paths: automated route selection for navigation(Springer, 2003)Numerous cognitive studies have indicated that the form andcomplexity of route instructions may be as important to human navigatorsas the overall length of route. Most automated navigation systemsrely on computing the solution to the shortest path problem, and not theproblem of finding the “simplest” path. This paper addresses the issueof finding the “simplest” paths through a network, in terms of the instructioncomplexity. We propose a “simplest” paths algorithm that hasquadratic computation time for a planar graph. An empirical study ofthe algorithm’s performance, based on an established cognitive model ofnavigation instruction complexity, revealed that the length of a simplestpath was on average only 16% longer than the length of the correspondingshortest path. In return for marginally longer routes, the simplest pathalgorithm seems to offer considerable advantages over shortest paths interms of their ease of description and execution. The conclusions indicateseveral areas for future research: in particular cognitive studies areneeded to verify these initial computational results. Potentially, the simplestpaths algorithm could be used to replace shortest paths algorithmsin any automated system for generating human navigation instructions,including in-car navigation systems, Internet driving direction servers,and other location-based services.
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ItemA formal model of obfuscation and negotiation for location privacy(Springer, 2005)Obfuscation concerns the practice of deliberately degradingthe quality of information in some way, so as to protect the privacy ofthe individual to whom that information refers. In this paper, we arguethat obfuscation is an important technique for protecting an individual’slocation privacy within a pervasive computing environment. The papersets out a formal framework within which obfuscated location-based servicesare defined. This framework provides a computationally efficientmechanism for balancing an individual’s need for high-quality informationservices against that individual’s need for location privacy. Negotiationis used to ensure that a location-based service provider receivesonly the information it needs to know in order to provide a service ofsatisfactory quality. The results of this work have implications for numerousapplications of mobile and location-aware systems, as they providea new theoretical foundation for addressing the privacy concerns thatare acknowledged to be retarding the widespread acceptance and use oflocation-based services.
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ItemSimulation of obfuscation and negotiation for location privacy(Springer, 2005)Current mobile computing systems can automatically sense and communicatedetailed data about a person’s location. Location privacy is an urgent researchissue because concerns about privacy are seen to be inhibiting the growthof mobile computing. This paper investigates a new technique for safeguardinglocation privacy, called obfuscation, which protects a person’s location privacy bydegrading the quality of information about that person’s location. Obfuscation isbased on spatial imperfection and offers an orthogonal approach to conventionaltechniques for safeguarding information about a person’s location. Imprecisionand inaccuracy are two types of imperfection that may be used to achieve obfuscation.A set of simulations are used to empirically evaluate different obfuscationstrategies based on imprecision and inaccuracy. The results show that obfuscationcan enable high quality of service in concert with high levels of privacy.
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ItemWhat is the region occupied by a set of points?(Springer, Berlin, 2006)There are many situations in GIScience where it would beuseful to be able to assign a region to characterize the space occupied bya set of points. Such a region should represent the location or configurationof the points as an aggregate, abstracting away from the individualpoints themselves. In this paper, we call such a region a ‘footprint’ forthe points. We investigate and compare a number of methods for producingsuch footprints, with respect to nine general criteria. The discussionidentifies a number of potential choices and avenues for further research.Finally, we contrast the related research already conducted in this area,highlighting differences between these existing constructs and our ‘footprints’.
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ItemA spatiotemporal model of obfuscation strategies and counter strategies for location privacy( 2006)Safeguarding location privacy is becoming a critical issue in location based services and location-aware computing generally. Two drawbacks of many previous models of location privacy are: 1) the models only consider a person’slocation privacy protection, but not the invasion of location privacy by external agents; and 2) the models are static and do not consider the spatiotemporal aspectsof movement. We argue that, to be complete, any model of location privacy needs to enable the analysis and identification of techniques both to protect and toinvade an individual’s location privacy over time. One way to protect an individual’s location privacy is to minimize the information revealed about a person’s location, termed obfuscation. This paper presents an explicitly spatiotemporalmodel of location privacy that models a third party’s limited knowledge of a mobileindividual’s location. We identify two core strategies that a third party canuse to refine its knowledge, so potentially invading that mobile individual’s locationprivacy. A global refinement strategy uses the entire history of knowledgeabout an agent’s location in a single step. A local refinement strategy iterativelyconstructs refined knowledge over time.We present a formal model of global andlocal refinement operators, and show how this formal model can be translatedinto a computational model in a simulation environment.
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ItemSimulation, Calibration and Validation of Recreational Agents in an Urban Park Environment(University of Arizona Press, 2008)
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ItemSpatial data integration: a necessity for spatially enabling government(University of Melbourne, The Centre for SDIs and Land Administration, 2007)Introduction Most governmental decisions involve a spatial component (Williamson and Wallace, 2006), therefore informative decision making within governments is highly reliant upon multi-sourced spatial data. The ability to spatially enable governments through the use of integrated multi-source spatial data at different governmental levels makes governmental decisions incredibly efficient (Mitchell, 2006b), though governments rarely produce all the data required for their business. Rather, they obtain and integrate data from different sources. However, the diversity of data producers hinders effective spatial data integration. There are many technical and non-technical obstacles in the integration of multi-sourced spatial data and this is one of the major problems in sharing and using spatial data among government organizations. From a technical perspective, spatial data may differ semantically, syntactically and structurally. Institutional, social, policy and legal issues also hinder data integration. In order to effectively overcome these issues, a holistic framework is required to manage and address the issues. SDIs aim to facilitate the integration of multi-source spatial data by providing a holistic framework in which spatial data stakeholders (governments, private sector, etc) interact with spatial data effectively through technological components. There are inconsistencies in the various data within an SDI which lead to data inconsistency and hinder data integration. These inconsistencies should be managed through the SDI framework. However, at the moment, the SDI framework does not deal with these inconsistencies effectively. Hence, we need to identify and map the inconsistencies and develop tools and guidelines within the framework of an SDI to manage them. This will then make it easier for data to be integrated across and within government organisations.