Filters
Availability
Publication Year
Resource Type
Faculty
School/Institute
Publication Search Results
Sort
Results per page
1 - 10 of 13
-
(2012)ThesisThis thesis has proposed and demonstrated a new 3D map which is realistic image-based, thus enabling geometry measurements and geo-location services. First and most important work of this study is the implementation of positioning and spatial measurements with image-based 3D maps, while current image-based 3D maps like Google Street View only provide virtual experience in terms of photos in which a number of details representing the topographic and terrain attributes are all lost, such as shapes and heights. Another contribution relates to quality analysis for a MRI 3D map. The research has deeply analyzed outlier impacts and introduced Dilution of Precision (DOP) values which are used to evaluate geometry quality for geo-referenced images either or measured vision points. In addition, the thesis has conducted a loose integration of mapping sensors like camera and GPS, and investigated image matching and stitching. The thesis has also proposed image-based 3D maps cooperated with Street View, in that panoramic viewing could make 3D maps more interactive with users, also bring an interesting immersive circumstance. This study has mainly focused on vision point positioning and implementation of spatial measurements on the MRI 3D map, analysis of data quality, outlier detection, and image processing. Users could obtain their orientation, position and object distance over basic functions of the MRI 3D map. A prototype geo-referencing system has been designed for the implementation of the MRI 3D mapping.
-
(2012)ThesisAs a highly demand construction material, ready-mixed concrete (RMC) is a common commodity in the construction industry. Because of its inherent characteristics and strict quality requirements, the production, delivery and placement process of RMC is a topic of interests to both contractors and material suppliers. Among the factors affecting the RMC supply performance, the dispatching schedule of delivery trucks has a direct effect on the total operation time and queuing time. The primary obstacles in determining optimal dispatching intervals are uncertainties in traffic and unloading activity. To offset the negative impacts of these uncertainties, it is important to set an inventory of delivery trucks in the supply chain is necessary. However, although inventory can ensure continuity, it can also lead to waste to a certain extent. Therefore, finding a cost-effective inventory control mode is necessary to improve the performance of the supply chain. This thesis develops a model where inventory control policies working on an RMC delivery process with the aim of optimizing the supply chain from the perspectives of both the contractor and supplier. This model will: (1) maintain the continuous work, (2) reduce the wasted time at the construction site, and (3) allocate trucks more efficiently. Data collection and implementation are based on a major building project in United Arab Emirates which required large amount of RMC. And the observed process consists of 502 RMC delivery cycles. On the basis of original model, two control policies are implemented in the model and compared in terms of their impact on process behaviour. The discrete event simulation (DES) model results illustrate the advantages of flexible dispatching intervals provided by fixed-quantity inventory control policy including maintaining continuous work and reducing waste. An alternative solution to the queuing problem is also discussed by comparing queuing model outputs to discrete event simulation outputs. The results show that the queuing model fails to provide an accurate estimation of queuing statues when managerial actions are involved. The decision makers, plant managers, and contractors could potentially take advantage of the findings of this thesis to better understand and manage their supply chain.
-
(2011)ThesisThe use of a Mobile Mapping System (MMS) to quickly collect large amounts of data has been proven to be a cost effective and very beneficial technology for Road Authorities around the world. Early in the development of MMS technology the Roads and Traffic Authority of NSW (RTA) recognised the benefits of utilising such a system in the management and maintenance of their state road network and developed the first generation GIPSICAM system. GIPSICAM, which is an acronym for “Global and Inertial Positioning Systems with Image Capture for Asset Management”, is the RTA’s in-house developed, operated and maintained vehicle-mounted MMS. The first generation GIPSICAM system (GCv1) had no stable configuration and was modified for each project it was used for. Then in 1999 the second generation GIPSICAM system (GCv2) was developed for the lead up to the 2000 Olympic Games. Development of GCv2 continued after the Olympic Games and its operation was institutionalised in the annual surveys of NSW state roads from 2001 onwards. In July 2004 a strategic report on RTA Pavement Condition Monitoring Equipment was released that identified GIPSICAM data as an important RTA corporate dataset. However, the report also identified serious reliability issues with GCv2 due to the ad-hoc nature of its development and the age of some of its technology and equipment. In early 2005 the decision was made to develop the third generation GIPSICAM system (GCv3), also known as “GIPSICAM Version 3”. The objective of the development work was to take advantage of the experience from previous generation GIPSICAM systems in order to design a MMS that utilises current technology to ensure that the RTA has a reliable, safe, efficient, accurate, high quality GIPSICAM capability for the purpose of rapid road asset data capture and other applications of MMS technology. GCv3 was completed in mid-2006 and officially commenced operations in September 2006, at the start of the 2006/2007 GIPSICAM survey season. This thesis outlines the development of GCv3, from the selection and modification of the vehicle, the selection and integration of component technologies, and the development of operational procedures for rapid road asset data capture.
-
(2012)ThesisThe kinetics of reactions of nanomolar concentrations of Cu(I) and Cu(II) with H2O2 have been investigated in 0.7 M NaCl and 2.0 mM NaHCO3 at pH 8.0. At these low concentrations of Cu(II), the reaction between Cu(II) and H2O2 was found to occur via the free radical mechanism in which Cu(II) was utilized through one-electron reduction that converted H2O2 into the intermediate reactive radical species O2 with a rate constant of 4.6 x 102 M-1s-1. Measurements of both hydroxylated phthalhydrazide (PhthOH) CL product and the degradation of radiolabelled formate in the absence and presence of known HO scavengers indicated that the reaction between Cu(I) and H2O2 did not occur via a Fenton-like mechanism under the experimental conditions investigated here but involved the formation of a higher oxidation state of copper, Cu(III), with a rate constant of 74 M-1s-1. HO plays an insignificant role because the decomposition of Cu(III) to yield HO is very slow (occurring with an upper limit of 1.6 x 10-4s-1). Cu(III) however, acting as the dominant oxidant, reacts with the substrates that were present (although at much lower rates compared to those of HO ). A kinetic model based on the CuL approach has been developed and shown to satisfactorily describe the reaction kinetics of the inorganic Cu(I)/Cu(II)/H2O2/O2 system over a range of experimental conditions. Key reactions in this kinetic model have been determined by sensitivity analysis.
-
(2013)ThesisA key limitation to further understanding of storm induced beach erosion and the development of accurate predictive coastal erosion models is the paucity of field scale data collected within a short period of time of an erosion event. The collection of this data is made difficult by the challenging coastal environment in addition to the episodic nature of coastal storms. This thesis introduces the method of rapid-response airborne lidar that was developed and tested in order to collect such data. A light aircraft mounted lidar system performed surveys with different flight configurations at the Narrabeen Embayment and the ability to resolve beach topography and derived coastal change were investigated. This was compared to the standard survey method of a GPS equipped ATV, with the airborne lidar surveys able to perform beach surveys at an accuracy on par with the ATV method, and able to derive a shoreline position and beach volume with a root means squared error of 0.94 m and 3.89 m3/ m when compared the ATV method. In order to reduce uncertainty as to the drivers of storm induced beach erosion, a nearshore spectral wave model was developed to transform the offshore deep water wave climate into a nearshore wave climate at 75 different locations within Narrabeen Embayment. This model was tested against nearshore wave observations taken from two wave rider buoys located within the embayment. The rapid-response airborne lidar capability was deployed immediately before, during and immediately after an East Coast Low storm event at the Narrabeen Embayment, representing an almost daily dataset of the rapidly evolving morphology. This survey data, which indicated considerable alongshore variation in the dune erosion response to the storm, was then combined with the measured and modelled hydrodynamic data to test several simple dune erosion models. The effect of forcing data resolution and alongshore averaging was also investigated. A modification to one of the models was presented, it showing modest improvement compared to the other models, being able to explain 67% of the observed dune erosion across the entire embayment.
-
(2012)ThesisThis thesis discusses alternatives to two project management techniques, the earned value approach for project performance reporting and the deterministic discounted cash flow analysis in decision making. Both are criticised in the literature due to their inherent deficiencies and inapplicability in practice. Earned value, a popular tool for forecasting project cost and schedules, has been criticised for its problematic formulation and implementation. These deficiencies are implicit in the method. The first section of the thesis presents a substitute for the earned value approach. The thesis argues that the state- space analysis is a viable alternative to the earned value approach by demonstrating the connection and the differences between the state space and the earned value methods. An example is taken to illustrate how the state space method works in practice. The second section of this thesis presents a new method, the second order moment approach, for option valuation at the investment decision stage. For the purpose of demonstrating the validity of the proposed method for valuing real options, a comparison in both formulation and calculation supports the equivalence between the second order moment and the Black-Sholes approach. Numerical testing then displays this equivalence. Finally, a mathematical method is proposed based on the second order moment approach and the project evaluation and review technique to support infrastructure investment decision making under climate change.
-
(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.
-
(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.
-
(2011)ThesisBushfires in Australia are amongst the most frequent, severe and extensive natural disasters in the world. Frequent bushfires destroy many natural resources and damage the forest’s biochemical chain and cause soil damage. Therefore, assessment of bushfire scars is a very important theme in observing Australia from space. Remotely sensed data is used operationally to map burned area and fire severity after major bushfires and to research the impact of prescribed burns. Several types of Remote Sensing data were collected in order to assess fire effects from both optical sensors and active microwave sensors. Optical data from more recent sensors are being used for mapping burned scars and fire severity. Active microwave Remote Sensing data, like RADAR can observe the Earth’s surface day and night under all cloud conditions. The usage of optical and Synthetic Aperture RADAR (SAR) Remote Sensing technologies can provide valuable information, analysis capability and more confidence for determining the extent of burned areas and estimating fire severity. A fusion of optical and active Remote Sensing would greatly improve post-fire scars mapping. This research focuses on two study areas. In the first burned area, Dargo - Dippsland, the operational application of both Advanced Land Observing Satellite L-band synthetic aperture RADAR (ALOS PALSAR) and Landsat Thematic Mapper (TM) data for mapping burned scars was evaluated. Both ALOS and Landsat data were acquired before and after the bushfires. Several different methodologies were analysed and compared to assess the bushfire scars, in terms of the image enhancement techniques, the band ratioing and texture transformation techniques, the principal components analysis (PCA) and the fusion of ALOS PALSAR and Landsat TM data. Results show that the technique based on PCA extracted from the fusion of Landat TM and filtered ALOS PALSAR images indicated a clear superiority on bushfire scars detection, which obtained an overall accuracy of 67.62% and a Kappa coefficient of 0.2443, followed by the classification based on the PCA extracted from the fusion of Landat TM and filtered ALOS PALSAR images (overall accuracy is 59.88% and a Kappa coefficient is 0.2026). It is noted that the ALOS PALSAR and Landsat TM fused images are much better than individual images to identify burned scars. Furthermore, the severity of a fire’s impact on vegetation was mapped in the second study area, Sharps Unit - Otway, using Landsat TM and ground truth data. Methods in this study highlight pre- and post-fire changes by computing the difference in the Normalised Burn Ratio (NBR) and the Normalised Difference Vegetation Index (NDVI) between the period of pre- and post-burn. Then the results show that the differenced NBR (dNBR) algorithm represented better severity classes’ result than the differenced NDVI (dNDVI). What means by this is NBR and dNBR were more sensitive to fire effects than NDVI and dNDVI. However, some issues should be considered in this process, for instance the threshold of severity classes should be considered carefully when placing the field plots thereby preventing the loss of fire severity evidence. The analysis will be valuable for understanding the different methodologies of mapping the bushfires scars and severity, and forming ecologically-sensitive approaches to fire management.
-
(2011)ThesisThe time is coming when regional and international conflicts will be about water supply since water touches nearly every aspect of life. Water is becoming a scarce commodity everywhere including Balochistan (Pakistan), where environmental challenges are at a peak. Most of the poor (Quetta, Pakistan) pay high prices for water from private vendors or, with their labour, collect free water from distant sources. Tragically, all the money paid to private water vendors could easily fund an adequate public piped water system. Imaginative tariffs for metered supply would be needed to ensure the poor were not excluded. The overall objective of the study is to discover gaps between demand and supply by collecting and analysing secondary and primary data related to cost recovery. From a survey of urban water users and water vendors in Quetta, Pakistan, about 40% of respondents have access to a piped supply. However the supply is irregular and unreliable. 50% percent of connections receive water for five or more hours per week but 25% have less than two hours supply per week. 92% percent of respondents thought water should be free. The very small monthly charge for an unmetered connection is PKR12 ($US0.17) but 50% of the connected respondents never pay, citing unreliability and un-affordability, and there is no mechanism for enforcement of payments. Water vendors (mainly using road tankers) deliver about 10Ml (mega litre) per day with a charge of about PKR1 ($US0.0.014) per 10 litres. The inequity and economic absurdity of the situation is obvious. Monies currently paid to water vendors would easily fund the operation of a potentially safe, reliable, piped water supply system for all. However, due to the very low payment collection, the water supply body cannot maintain its inadequate system. Construction of a universal self funding piped and metered supply system would seem to be the logical solution. However, before self funding could be realised, a major public education program would be needed to teach the population about the real cost of water and to inform the legislators of the need for enforcing water charges.