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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    Bridging SDI design gaps
    MOHAMMADI, HOSSEIN ; RAJABIFARD, ABBAS ; BINNS, ANDREW ; Williamson, Ian P. (Centre of Geo-Information Technologies (cGIT), 2006)
    The environment we inhabit is integrated and to properly manage the environment it is necessary to look at all environmental components and making multi-criteria decision about environment mostly needs an integrated view of built and natural environmental components to better interpret it.Despite the integrated nature of environment and requirements of users to integrate different components of environment, information about different elements of environment is being collected and managed by fragmented agencies under different and mostly inconsistent policies and standards to satisfy their own needs –for a single discipline- with little attention to the broad range of users – a multi-disciplinary approach. This fragmentation results in heterogeneity of technical and non-technical issues surrounding integration of datasets.An SDI is an initiative to facilitate the cooperation among all stakeholders and the interaction with standards and technological components and one of its objectives is to facilitate the integration of multi-source spatial data sets.This paper aims to address different issues connected to the integration of multi-source data sets in order to better serve different communities through their SDI initiatives and also a better management and sharing of their spatial data. The paper aims to discuss both technical and non-technical issues related to the integration of multi-source data sets in alignment with an ongoing research project devoted to developing models, guidelines and associated tools to facilitate the integration of multi-source datasets within an SDI.
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    The role of sub-national government and the private sector in future Spatial Data Infrastructures
    Rajabifard, A. ; Binns, A. ; Masser, I. ; Williamson, I. P. ( 2006-08)
    A Spatial Data Infrastructure (SDI) facilitates and coordinates the exchange and sharing of spatial data between stakeholders in the spatial data community. With this objective in mind, countries throughout the world are developing SDIs to manage and utilise their spatial data assets more effectively. These countries are developing SDIs to assist in various kinds of decision-making at different levels of government jurisdictions that have an important impact within their national boundaries. However, current research shows that SDI is understood and described differently by stakeholders from different disciplines and different jurisdictional levels. Therefore, in many cases SDI initiatives remain very much an innovation even among practitioners. There are still uncertainties regarding the benefits and identities of SDIs, particularly in connection with how they evolve over time to meet user needs.This paper reviews and assesses the development of SDIs throughout the world over the past fifteen years and the leadership role of national governments in SDI creation. This assessment is based on the SDI activities of various jurisdictions including Asia-Pacific, Australia, North America and Europe and research into the worldwide effects of spatial information clearinghouses. This assessment includes a discussion on emerging trends in SDI development, with particular reference to the increasingly important role played by sub-national governments and the private sector within the framework of SDI development. The paper concludes with a discussion of the implications for future SDI development, including the delivery of a virtual world that has a particular focus on facilitating decision making at a community level within a national context.
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    Assessing the worldwide comparison of cadastral systems
    RAJABIFARD, ABBAS ; Williamson, Ian P. ; STEUDLER, DANIEL ; BINNS, ANDREW ; King, Mathew (Elsevier, 2006)
    There is growing interest internationally in land administration and cadastral systems and especially in their role as part of a national Spatial Data Infrastructure (SDI). The important role the cadastre plays in supporting sustainable development is also well recognised. Both developed and developing countries accept the need to evaluate cadastral systems to help identify areas of improvement and whether their systems are capable of addressing future needs. Countries are continually re-engineering and implementing various aspects of the cadastre, comparing systems and trying to identify best practice within nations of the same socio-economic standing.In order to address this need, members of a team from the Centre for Spatial Data Infrastructures and Land Administration at the Department of Geomatics, the University of Melbourne, with the support of the United Nations Permanent Committee on GIS Infrastructure for Asia and the Pacific (PCGIAP) and the International Federation of Surveyors (FIG), have developed a cadastral template. The template aims to assist the evaluation and benchmarking of cadastral systems and the role they play in spatial data infrastructures.This paper aims to outline the concept and theory behind the cadastral template as well as analysing the results from 34 completed country templates. Several indicators have been used to analyse and benchmark countries cadastral systems, results of which will contribute to an improved understanding of the complex relationship between cadastral, land administration system and National SDI initiatives. This will also enable a worldwide comparison of cadastral systems, forming the basis for best practice and a tool to improve national cadastral systems.
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    Discuss: a soft computing approach tospatial disaggregation in economicevaluation of public policies
    Paez, D. ; Williamson, I. P. ; Bishop, I. D. (Blackwell, 2006)
    For more than three decades cost-benefit analysis (CBA) has been used in manycountries as an important tool for evaluating public policies. More recently, participationof stakeholders in CBA processes has become an important issue for governments.However, CBA by itself does not provide a good environment for stakeholderparticipation. A major reason for this is the lack of spatial disaggregation intraditional CBA. In order to allow greater public participation, a GIS-based approachis proposed. This approach uses a Geocomputational system, which incorporates softcomputing theory with expert systems in a geographic information systems (GIS)environment. It is designed to generate representations of environmental, economicand social policy outcomes according to the perceptions of the stakeholders and afterthe CBA results have been obtained. The methodology proposed for modellingimpacts in cases where uncertainty exists uses the soft computing theory of fuzzy logicto generate a raster map based on spatial inputs provided by the stakeholders involvedin the decision process. This computer-based system, called DISCUSS (DecisionInformation System for Community Understanding of Spatial Scenarios), is intendedfor situations where the government chooses to evaluate a policy using CBA anddesires to encourage public participation in evaluating the results identified by theeconomic methodology. DISCUSS and the maps that it produces are being testedin a public participation case study with long-term impacts over a large area ofsouth-eastern Australia.
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    The role [of] cadastral data modelling in e-land administration
    Kalantari, M. ; Rajabifard, A. ; Wallace, J. ; Williamson, I. P. (Centre of Geo-Information Technologies (cGIT), 2005)
    Enablement of land administration with Information and Communication Technology (ICT) is heading toward e-Land Administration (e-LA): the transformation of land administration through the use of ICT. Existing initiatives include providing land information on line, electronic conveyancing, digital lodgement of survey plans, and online access to survey plan information. Thus far, implementation of these initiatives is isolated in their specific subsystems without reference to the broader land administration system or its core policy function of supporting sustainable development. One solution to isolation is to develop effective communication among the different land administration subsystems by harmonising data and functionalities, so they are capable of being used by all subsystems. The key to harmonisation is data modelling which both recognizes and reengineers existing business processes. Modelling allows every single process in land administration to influence the cadastral data model and vice versa. This paper describes the importance of cadastral data modelling in data management as well as coordination among subsystems in an e-LA.