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(2010)ThesisUsing CORS networks for land reconstruction after earthquakes and tsunamis is challenging due to the limited infrastructure remaining after the event. Normally, CORS networks are set up in well established cities of regions with developed infrastructure and utilities. The functionality of a CORS approach is suitable to re-establish more than 10,000 land parcels in Aceh affected by the tsunami, but can this method still be useful with limited infrastructure? Also, can a CORS network feasibly re-establish cadastral land parcel boundaries previously based on bearings and distances using coordinates? This is a very crucial problem as often no survey marks exist to re-establish property boundaries. CORS networks can provide an external infrastructure allowing the identification of existing survey marks and the lay out of new and existing parcels for a large number of independent users. Using sophisticated network RTK algorithms, larger inter-receiver distances allow CORS networks 10 cover large areas with a minimal number of reference stations reducing the cost of operations. Also in equatorial regions, such as Aceh, where ionospheric activity is expected to be higher, a slightly denser array of CORS stations ensures reliable initialization. This thesis tries to investigate the utilization of temporary CORS network approach; that is using some higher order stations as base station monuments, setting up a temporary CORS network over a small region and when operations are completed. packing up the system and moving to an adjacent network of high order monuments which comprise a new temporary CORS networks. Due to logistical consideration during the organization of this project, real-time communications were not used in Aceh and only GPS data was logged in the field. Reference stations logged 24 hours of GPS data and were processed using the free online service from AUSPOS. These coordinates are then used in a post-processed simulation mode using the Leica SpiderNet software. As a comparison, there is a similar simulation that has been conducted using the well established network RTK GPS infrastructure that belongs to Singapore Land Authority (SLA) in Singapore. The Aceh data simulation showed that the network. RTK suffered from bad network geometry and lack of the common satellite number. On the other hand, the SLA data struggled in network ambiguity resolution due to ionospheric activity in equatorial region. Overall, single based and network RTK GPS is still reliable if it is used in land reconstruction in equatorial region. But it has to give more attention in the extending range and high density of reference stations.
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(2010)ThesisService-Oriented Computing (SOC) has become increasingly popular as it offers a technology-independent view of systems and is enabled by Web Service technologies. It is being adopted by many businesses to implement their business processes on top of Service-Oriented Architectures (SOA). As the demand of these business processes grow, it is increasingly difficult to scale the service from both software and hardware perspectives. Although there are computing concepts such as Grid Computing and Utility Computing which allow businesses to achieve this by making architectural changes, there is currently a lack of academic literature and practical knowledge that can be used by business software developers to take advantage of these computing concepts. In this thesis, we choose to model key architectural decisions that are critical to a Web Service to Grid Service migration. We formalize the corresponding design process using the Architectural Decision-Making Support (ADEMS) framework, which is a systematic, quantitative, disciplined and methodological approach for designing complex systems. In order to validate the benefits and practicality this process can bring to businesses, we apply it to a realistic case study in the capital market industry. The results indicate that this approach can provide business stakeholders the first step in reasoning about optimal architectural decision choices for further developments. The thesis concludes by providing avenues for future work towards formalizing& design processes for service-oriented systems.
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(2010)ThesisAs GLONASS has gradually been developed towards its full constellation, it becomes clear that GLONASS will bring significant benefits to worldwide geodetic applications of global satellite navigation systems. With the recent revitalization of GLONASS, GPS/GLONASS receivers have been equipped at most International GNSS Service (IGS) tracking stations and regional CORS networks worldwide. Precise IGS orbits for GLONASS, consistent GPS/GLONASS CODE orbits as well as combined GPS/GLONASS observations are available for users. So it becomes worthwhile to investigate the advantages of the combined GPS/GLONASS solutions for precise surveying and geodetic applications. This research focuses on analysing combined GPS/GLONASS observations for long baselines and short baselines. Both mathematical model and stochastic model have been discussed based on the results from the observations obtained from IGS stations and testing observations for rapid static baselines. This thesis has focused on the following major aspects: a) Modelling for combined GPS/GLONASS data processing. The possible mathematical models have been discussed and verified with numerical results. For stochastic modelling, the elevation-based model, SNR-based model and a real-time stochastic model have been analysed. b) GPS/GLONASS data processing for long baselines. GPS and GPS/GLONASS long baselines from two networks have been analysed, aiming to assess the influence of adding GLONASS data to the GPS-only long baseline solutions. The IGS final GPS precise orbits and fully consistent GPS/GLONASS orbits from CODE have been utilised in all these baseline solutions. GPS-only and GPS/GLONASS observations have been processed respectively, using the same processing strategy. The results of the GPS-only baselines and GPS/GLONASS baselines have been compared. It has been demonstrated that the accuracy for long baselines cannot be improved significantly by introducing GLONASS observations. c) GPS/GLONASS data processing for rapid static baselines. Observations from rapid static baseline have been processed using Leica Geo Office, and the results from GPS-only baselines and combined GPS/GLONASS baselines have been analysed. From the results, it can be seen that the accuracy have been improved by integrating GPS/GLONASS for rapid static baselines in built-up areas.
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(2010)ThesisThis thesis aims to examine the efficiency of opportunistic multicast routing in Wireless Mesh Network (WMN). Specifically, an opportunistic multicast routing protocol has been developed in this work in order to gain better performance in WMNs compared to traditional multicast routing protocols. The number of transmissions in the network to deliver a packet from a source to group of destinations has been taken as measure for the performance of the protocol. Less number of transmissions in the network to deliver a packet to group of destinations is an indicator for a better performance. The work has been divided into two parts. In the first part, a proposal of the first version of opportunistic multicast routing protocol (OMRPv1) will be explained. By calculating the expected number of transmissions in the network, the efficiency of the protocol will be examined. OMRPv1 will be compared against a traditional protocol, non-opportunistic protocol, to confirm its better performance in the network. Then, a second version of our protocol will be introduced, OMRPv2, as a solution for some problems encountered in the first version. The comparison between OMRPv1 and OMRPv2 will show the better performance achieved with the newer version. In the second part, QualNet simulator will be used to simulate the protocol OMRPv2. In this part, not only the number of transmissions in the network will be considered, but also other metrics like end to end delay and delivery rate will be taken into account. The overhead of the protocol will be examined as well. Observation of the results from the simulation will lead to the third version of the protocol (OMRPv3). OMRPv3 will be simulated as well to show the improvement in the performance over the previous version OMRPv2. Finally, OMRPv3 will be compared to the best opportunistic multicast routing protocol in the literature, Beacon-less Geographic Routing for Multicast Applications (BRUMA). For that reason, BRUMA will be simulated in QualNet as well. For fair comparison, few modifications will be added to BRUMA. Then, the two protocols will be compared to each other using many metrics. Delivery rate, end to end delay, and number of transmissions in the network to serve the multicast groups are some of the metrics that will be used to compare the two protocols. Results show that our protocol, OMRPv3, outperforms BRUMA in many of these metrics.
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(2010)ThesisIn traditional infrastructural wireless local area network (WLAN), the mobile node (MN) makes the decision of choosing an access point (AP). The MN creates a list of APs in range along with the received signal strength indicator (RSSI). It then solely uses the RSSI as a decision metric for selecting an AP to connect to as this is the only information available at the MN. We argue that a MN is not the correct entity in WLAN for making the choice of an AP when many APs are available as it does not have the complete view of the environment. Secondly, choosing an AP solely on the basis of RSSI is not an efficient algorithm. This can lead to concentration of MNs at single AP resulting in a decreased average throughput for every MN associated to that AP. In this thesis, we propose to transfer this decision to the AP in a transparent manner. While our solution exists for single administrative domain with a centralized controller, we propose a completely distributed architecture for personal WLANs where APs select to serve MNs based on the MN concentration, network load, throughput and effect of serving a new MN on the network. The APs in different networks collaborate among one another in a completely decentralized manner to provide unified network access to MNs with focus on maximizing the system capacity. The broadcast nature of wireless is used in an intelligent manner to select dynamic uplink and downlink paths between APs and MNs.
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(2010)ThesisA canine ventricular dataset was obtained from the modelling team at the Bioengineering Institute, University of Auckland, formatted for use with the CMISS modelling package developed by that group. In the work of this thesis, the Auckland dataset was imported into the COMSOL commercial modelling package. In doing so, the dataset was translated from a cubic Hermite representation of anatomical structure to a Bézier curve based representation. In addition, a simple monodomain model of electrical activity was solved over the ventricular geometry. The original elements of the model were either hexahedral or triangular prisms, referred to as wedges. Scale factors were calculated to convert local nodal values to global values for use with the Bézier curves. These scale factors were calculated differently in wedge elements due to their geometry. Alternative scripts were created to account for these differences. After importation into COMSOL, it was found that Hermite interpolation was unable to accurately model discontinuous bifurcations of anatomical structures, due to a continuity requirement within the Hermite scheme, leading to parallel and overlapping element edges.. Bézier curves are not subject to this restriction, and were found to be more appropriate in modelling these cases. To validate the import process from CMISS into COMSOL, a right lung lobe dataset was also successfully converted and graphically represented. The CMISS data on the canine ventricles also contains histological information on myocyte fibre orientation, which was not incorporated in the present study. It is known that this fibre orientation affects action potential propagation in the heart. Future work will need to address this area.
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(2010)ThesisMobile location methods that employ signal fingerprints are becoming increasingly popular in a number of wireless positioning solutions. A fingerprint is a spatial database, created either by recorded measurement or simulation, of the radio environment. It is used to assign signal characteristics such as received signal strength or power delay profiles to an actual location. Measurements made by either the handset or the network, are then matched to those in the fingerprint in order to determine a location. Creation of the fingerprint by an a priori measurement stage is costly and time consuming. Virtual fingerprints, those created by a ray-tracing radio propagation prediction tool, normally require a lengthy off-line simulation mode that needs to be repeated each time changes are made to the network or built environment. An open research question exists of whether a virtual fingerprint could be created dynamically via a ray-trace model embedded on a mobile handset for positioning purposes. The key aim of this thesis is to investigate the trade-off between complexity of the physics required for ray-tracing models and the accuracy of the virtual fingerprints they produce. The most demanding computational phase of a ray-trace simulation is the ray-path finding stage, whereby a distribution of rays cast from a source point, interacting with walls and edges by reflection and diffraction phenomena are traced to a set of receive points. Due to this, we specifically develop a new technique that decreases the computation of the ray-path finding stage. The new technique utilises a modified method of images rather than brute-force ray casting. It leads to the creation of virtual fingerprints requiring significantly less computation effort relative to ray casting techniques, with only small decreases in accuracy. Our new technique for virtual fingerprint creation was then applied to the development of a signal strength fingerprint for a 3G UMTS network covering the Sydney central business district. Our main goal was to determine whether on current mobile handsets, a sub-50m location accuracy could be achieved within a few seconds timescale using our system. The results show that this was in fact achievable. We also show how virtual fingerprinting can lead to more accurate solutions. Based on these results we claim user embedded fingerprinting is now a viable alternative to a priori measurement schemes.
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(2010)ThesisEnergy efficiency techniques in the built environment offer some of the most economical methods of reducing greenhouse gas emissions. This dissertation examines some of the options for reducing the greenhouse gas emissions associated with the operation of a retail warehouse building in the Sydney climate. The research was undertaken using DesignBuilder, EnergyPlus, Ecotect and Radiance software packages to simulate variations of a model with the ultimate goal of achieving a net-zero energy building. The research was divided into two main sections. In the first section, some techniques that can be used to increase the energy efficiency of a retail warehouse building were explored with the aim of reducing the energy use to close to a minimum level. The techniques examined include increased insulation, improved roof lighting, the use of natural ventilation and the use of efficient artificial lighting. When compared to the base case building, savings of up to 73% of the annual energy use were achieved using these relatively simple techniques. The second section examines the effect of changes made to the regulation of roof lights as specified in Section J of the 2010 version of the Building Code of Australia (BCA) which provides the mandatory minimum building standards for all Australian commercial buildings. A base case model was simulated with various roof lighting options to determine the effect of recent changes to these regulations. Additionally, the size of a photovoltaic array large enough to provide an annual output of energy equal to the annual energy consumption of the building, was calculated for each of these models, effectively making them zero energy buildings. The difference in the capital expenditure for these zero energy models were compared and it was found that for this particular building, the changes made in the 2010 version of the BCA resulted in a less efficient and more expensive building. It is concluded that the changes have focused on improving the heat transfer properties of the roof lights to the detriment of the daylight penetration properties. To ensure the next generation of buildings are more energy efficient, consideration needs to be given to both the thermal and the daylight properties of roof light materials.
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(2010)ThesisThe interaction of ocean waves and turbulence is a fundamental process in the ocean. Understanding and prediction of wind-wave generation, propagation, breaking, non-linear interactions and extreme wave development are directly linked to this complex and not well understood phenomenon (Thorpe 2005). Despite its significance in ocean engineering, there are no complete theories that explain the influence of turbulence in these processes. Further, available laboratory and field observations are limited mainly due to the difficulty in measuring turbulence within a wave field, particularly in the region above the wave trough. Instead most engineering applications rely on parameterizations and formulas based on empirical relations and the linear wave theory, which potential flow assumption does not support turbulence (CEM2008, SPM84). This lack of understanding of the wave-turbulence interaction processes is in part responsible for inaccurate predictions that ultimately translate in higher failure risks, and infrastructure and operational costs for engineering and navigational assets. In this investigation two new wave tank laboratory experiments have been developed to enhance present understanding on wave-turbulence interactions. The first experiment quantified the attenuation of deep water surface waves caused by rainfall induced subsurface turbulence. Significant challenges in the measurement and extraction of the turbulence statistics were overcome. Observations of near-surface velocity fluctuations revealed that wave attenuation rates induced by the unexpectedly weak rainfall-triggered turbulence were greater than previously anticipated by Teixeira and Belcher (2002). Measured near-surface velocity fluctuations are also in excellent agreement with Braun (2003) but contrast strongly with recent measurements by Zappa et al. (2009) and well-established theories that predict high levels of rainfall induced subsurface turbulence (e.g. Ho et al. 2000). The second experiment intended to verify a controversial and recently proposed laminar-turbulence transition produced under steep freely propagating deep water waves (Babanin and Haus 2009). This new finding has major implications that could dramatically change present understanding of ocean waves. Dye visualization experiments showed no evidence of turbulence unless wave steepness was large enough to produce breaking. Moreover, unique measurements of the Stokes drift and the Stokes harmonic coefficients showed remarkable agreement with high order irrotational Stokes theories. However, measured higher order Stokes coefficients were larger than the theoretical predictions. Nevertheless, general good agreement of the present observations with the irrotational theories is in contrast with the recent challenges by Monismith et al. (2007) who proposed the cancellation of the Stokes drift and inferred closed orbital particle paths in freely propagating waves.
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(2010)ThesisEndocrine disrupting chemicals (EDCs) are chemicals that alter functions of the endocrine system and cause health effects in an intact organism, or progeny, or population, with reproductive, developmental, or carcinogenic consequences. In order to facilitate risk assessment of potential endocrine disrupting steroids that are present in ultra low concentrations in the Australian environment, there is a need to boost the analytical capacity for EDC detection. One strategy is to develop antibody-based techniques that can offer simple, cost-effective and reliable analysis with high throughput capacity and portability for real-time monitoring. This thesis describes the design and synthesis of hapten molecules, raising of specific antibodies, formatting and characterising of a series of sensitive competitive Enzyme-Linked Immunosorbent Assays (ELISAs) for 17β-estradiol (E2), 17α-ethynylestradiol (EE2), ethylestradiol-3-methyl ether (mestranol) and testosterone (T), including validation of their performance as fast and effective water monitoring tools. Application of the developed assays to investigate the levels of the target EDCs in bodies of water and efficiency of water treatment plants in urban and rural areas in New South Wales, Australia, is also discussed. 17α-Ethynylestradiol and related synthetic estrogens, are active ingredients of contraceptive pills and hormone therapy, and have been identified as potent EDCs (Warner and Jenkins, 2007). In Chapter 3, the development of two ELISAs with varying specificity for the synthetic estrogens is described; 1) a highly sensitive ELISA for 17α-ethynylestradiol and mestranol, and 2) a mestranol specific ELISA. Highly specific antibodies was facilitated by synthesising haptens with the attachment of linkers with varying lengths at the C3 position (17α-ethynylestradiol-acetate hapten (EE2-ACT-KLH) and 17α-ethynylestradiol-butyrate hapten (EE2-BUT-KLH)). The optimised ELISAs in heterologous systems displayed high sensitivity, with the best assay exhibiting a limit of detection (LOD) of 70 ng L-1 EE2 in water (without preconcentration). The LOD of the ELISA covering the preconcentration step was 0.13 ng L-1 EE2 in water samples. This ELISA also correlated well with GC-MS (R2 = 0.934) data that were conducted independently for the same spiked samples. In Chapter 4, the development and validation of competitive direct ELISAs (cd ELISA) for the detection of 17β-estradiol (E2) in water at sub-parts per trillion levels is described. The specific polyclonal antibodies were raised against KLH conjugates of 17β-estradiol-acetate hapten (E2-ACT-KLH) and 17β-estradiol-butyrate hapten (E2-BUT-KLH), using a similar hapten synthesis approach as for 17α-ethynylestradiol. The developed ELISA (denoted as E2 ELISA) was highly specific to 17β-estradiol with a LOD of 50 ngL-1 in water (without preconcentration), with high matrix tolerance. The LOD of the E2 ELISA covering the preconcentration step was 0.03 ngL-1in water samples. Validation of ELISA performance against an independently performed GC-MS method indicated good correlation with a R2 value of 0.936. In Chapter 5, the development of an ELISA specific for testosterone with respect to the desired sensitivity and specificity for environmental analysis is described. The ELISA presented with a LOD and IC50 value at 0.07 ng L-1 and 0.4 ng L-1, respectively, and an excellent specificity. Unlike previously described assays for the estrogens, this assay was more matrix sensitive. Hence, an alternative or enhanced sample preparation step prior to assay was deemed essential to improve assay performance. Finally, in Chapter 6, the application of these developed ELISAs for the investigation of the quality of influent and effluents from various Sewage Treatment Plants (STPs) and nearby water resources in New South Wales, Australia, is described. The estrogenic and androgenic activities of the respective water samples were 0.20 to 6.28 ng L-1 estradiol equivalents and 0.01 to 0.64 ngL-1 testosterone equivalents, respectively, as measured by the yeast screening assays. Regular monitoring of EDCs should be conducted to ensure the levels and the contribution of estrogenic potency in water bodies is maintained below the ecotoxicologically significant level of 10 ngL-1 (Fenske et al., 2005, Huschek and Hansen, 2005). In addition, agricultural practices including live stock husbandry should be controlled to a certain distance away from water sources as a precautionary measure to reduce estrogenic potency in our water resources. In conclusion, a satisfactory agreement in data for E2, EE2 and T was obtained between ELISAs, GC-MS, and the estrogenic/androgenic activities measured by the yeast screening assays, although a slightly higher estimation was observed by ELISA. This suggests that ELISAs developed in this project can be used as fast and cost effective water quality monitoring tools. The high sensitivity and specificity of these ELISAs allow them to be used to monitor with acceptable reliability of the estrogenic and androgenic steroids at low parts per trillion levels after a simple concentration step.