Infrastructure Engineering - Theses
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ItemGIS applied to administrative boundary design( 2003)The fragmentation of administrative boundaries is a serious problem in the analysis of social, environmental and economic data. This research focuses on the development of a coordinated approach to the design of administrative boundaries that endeavours to support accurate decision making. Around the world, administrative boundaries have been structured in an uncoordinated manner, limiting data exchange and integration between organisations. The solution proposed in this research adopts the hierarchical reorganisation of administrative boundaries to enhance data integration and data exchange within the spatial data infrastructure (SDI) framework.The SDI is an initiative intended to facilitate access to complete and consistent data sets. One of the most fundamental problems restricting the objectives of the SDI is the fragmentation of data between non-coterminous boundary systems. The majority of administrative boundaries have been constructed by individual agencies to meet individual needs. Examples of the proliferation of different boundary systems include postcodes, census-collector districts, health districts and police districts. Due to the lack of coordination between boundary systems, current technologies for analysing spatial data, such as geographic information systems (GIS), are not reaching their full potential. A review of the current literature reveals that, until now, little has been done to solve this problem.The prototype developed within this research provides a new mechanism for the design of administrative boundaries. The prototype incorporates two algorithms. These are based on HSR theory and administrative-agency constraints and are implemented within the GIS environment. Such an approach is an example of the potential that is available when we link spatial information theory with the SDI framework and disciplinary knowledge.
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ItemExpanding the Spatial Data Infrastructure model to support spatial wireless applications( 2003-11)In response to a growing recognition of the importance of spatial information, the concept of Spatial Data Infrastructure (SDI) has evolved. Designed to facilitate an environment that promotes access and sharing of spatial information, SDI development has benefited from, and in due course adopted, advances in information technology (particularly improvements in desktop computing capabilities and communication networks such as the Internet). The never ceasing progression of technology now enables communication and data access via mobile phones and a myriad of portable, networked computing devices. Indeed over the last few years, the proliferation of mobile phones has exceeded many expectations and is enabling nomadic users to communicate and access data services with ease. Location is one of the unique characteristics of mobility that is encompassed by this form of wireless communication and has been capitalised on in the form of enhanced safety initiatives. In turn, the infrastructure required for these safety services has encouraged additional Location Based Services (LBS) to flourish LBS act as spatial decision making tools, providing information to end users based on their location, or on the location of some target. LBS are not restricted to the wireless environment however this is their current area of promotion. The principles of accessing spatial information that are encompassed by LBS mirror those of SDIs, and as a result SDI models need to accommodate for this new medium of information access and delivery. This research aimed to expand the SDI model to support applications that assist with spatial decision making, such as LBS. Focused specifically on LBS that are accessible for wirelessly networked, portable devices, this research implemented a theoretical and practical approach to identify the additional requirements for SDIs in this domain. A prototype LBS application for public transport information and navigation was developed and evaluated as part of this process. It is proposed that the resulting model (which details the additional requirements as well as their relative importance) act as an example framework for future LBS implementations so that they may gain the benefits from a standard, integrated infrastructure as offered by SDIs.
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ItemThe effect of adverse possession on part of a registered title land parcel( 2003-01)This thesis began as an investigation of the effect of adverse possession upon the land market where the adverse possession extends only to a small portion of the abutting parcel and the subject land is under a title registration scheme. The consequence of such adverse possession on part only of a parcel is that the location of the boundary demarcating the limits of the respective domains of two adjoining land parcels may be displaced. If part parcel adverse possession effectively transfers ownership of a small portion of an abutting parcel, the boundaries are shifted consequent to long term occupation, and will prevail over the strict technical legal boundary. In a registered title land system the occupational boundary then prevails over the legal boundary as certified in the register notwithstanding that registered title schemes purport to confer conclusiveness upon register entries. Alternatively, the registered proprietor’s estate is not paramount where any part of the proprietor's parcel has been adversely occupied. Consequently the occupier has an interest in the proprietor's land that is not disclosed in the register. Inspection of the register and reliance upon the inspection is insufficient to ascertain the complete legal status of the particular land holding. Inspection with consequent reliance upon the register is the major function of a registered title scheme. Alternatively, if part parcel adverse possession is ineffective to transfer ownership of registered land, the technical legal boundary prevails over the occupational boundary despite the fact that it is not the boundary accepted by the parties involved as governing. Both alternatives present a problem to the orderly conduct of the land market. Where occupations prevail, the prudent market participant takes precautions besides relying on inspection of the register. Where the legal boundary prevails, the participant seeks confirmation that the occupational and legal boundaries coincide. Another alternative utilised in some registered title jurisdictions empowers a court to transfer small sections to an adjoining landholder where a building or similar improvement is erected so that it encroaches upon the adjacent holding. This alternative was included within the ambit of the thesis as it developed. The aim of this research was the formulation of the best solution suitable for a registered land system with particular reference towards a uniform solution suitable for adoption in all Australian jurisdictions. The existing systems utilising adverse possession and statutory encroachment were evaluated against three recent law cases that illustrate the workings of these systems including perceived shortcomings. These lawsuits serve as a test against which the existing systems are compared and evaluated and were also used to evaluate the proposed solution. The results suggest that adverse possession alone should not override the purpose of the register which is to fully disclose the proprietary interests in land parcels. It was concluded that a necessary step in acquiring title to land through adverse possession involves the registration of the interest acquired. Whereas the present modes of dealing with the boundary problem are adequate, it is concluded that the best mode is that of statutory encroachment because it best serves several competing interests. Adopting the proposed solution would involve change and compromise in some of the Australian jurisdictions; these being necessary to adopt a uniform scheme throughout Australia. The proposed solution has added benefits of removing an illogicality from some of the present systems, eliminating encouragement for an off-register land market, and fosters an accurate public land register.
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ItemModal testing of bridge superstructures subjected to traffic excitation using the methods of data dependent systems( 2003)The aim of this thesis covers the development and application of the time domain multivariate auto regressive moving average (ARMA) modelling approach to the system identification of bridge superstructures subjected to ambient traffic excitation. Procedures for system identification of structures can be divided into two categories: i) Frequency domain methods; ii) Time domain methods. Traditional frequency domain methods of system identification are primarily based on Fourier Transform techniques. The Fourier Transform of uniformly sampled data is usually performed using the so-called "Fast Fourier Transform" (FFT) algorithm. FFT algorithms are at the heart of most popular commercial Fourier analysers. The reason for their popularity is speed of execution and reliability. However, deficiencies exist in these methods, particularly when dealing with systems subjected to ambient excitation, high noise levels, high damping levels or closely spaced modes. The recognition of these specific weaknesses in the frequency domain approach coupled with the additional expense associated with the necessity of introducing controlled excitation of the structures under test has led to the development of several time domain based methods of vibration analysis. However, the implementation of multivariate ARMA modelling in structural system identification applications is demanding of computational resources. In addition, this form of modelling is complex requiring a user-friendly interface for it to be attractive to civil engineers. Recent developments in both computer and the advent of suitable software platforms such as MATLAB have made this task feasible for large civil engineering structures. The majority of civil engineers still prefer to use the FFT based computer packages which are readily available. The use of the multivariate ARMA model, however, is reasonably wide spread in other areas such as electrical engineering and economics, improving considerably on the trial and error approaches associated with most other techniques in this field. The general purpose of system identification of civil engineering structures is to serve as a tool for performing modal analysis. A major part of the study associated with this thesis has focused on the development of the mathematical framework of ARMAV models or equivalent stochastic state space realisation methodology for system identification of civil engineering structures subjected to ambient excitation. The other major part focused on the application of the developed mathematical framework to a simulated three degree-of-freedom system and to two different in-situ bridge superstructures subjected to ambient traffic excitation. For improving accuracy, the off-line non-linear Prediction Error Method (PEM) has been used for extracting model parameters and estimating covariance matrices. Also by using the PEM, it has been possible to estimate the standard deviations associated with modal parameter estimates. The results obtained from application of the ARMAV approach to in-situ bridge superstructures are compared with those obtained using the FFT-based Simplified Experimental Modal Analysis (SEMA) technique and the time-domain Random Decrement method (RANDEC). A finite element method (FEM) model was constructed for each application which was then updated on the basis of the bridge geometry and experimental results obtained after testing. It is concluded that the autoregressive moving average vector (ARMAV) model is a viable alternative to traditional FFT-based techniques especially in situations where modes are closely spaced and when data is highly contaminated with noise as it is generally the case with traffic excitation. In addition the ARMAV modelling approach when used together with the off-line non-linear PEM offers a means of identifying and estimating the errors in parameters estimated from the modelling approach (viz: natural frequencies, damping and mode shapes in the context of modal analysis) which is difficult if not nigh impossible to achieve using traditional Fourier based techniques.