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(2008)ThesisThe present study is focused on two studies. The kinetics 0: methane steam reforming over a Ni/MgO catalyst at high pressure is reported in the first study. The second study is focused on the steam iron process over promoted Fe-oxide based catalyst using four different reductants; H2, H2 /CO mixture, CH4 and CH4 /C02 mixture. A kinetic study of methane steam reforming over a Ni/MgO catalyst at high pressure was carried out. The kinetic orders of methane and steam at 40 bars and 600 QC were found to be 0.82 and 0.62 respectively. 1~he estimation of energy of activation of the process was found to be 106 KJ/mol. T11e reaction rate data was explained by a Langmuir - Hinshelwood - Hougen - Wastson model. Four differe11t reductants (H2, H2 /CO mixture, CI-4 and CH4 /C02 mixture) , were applied for the study of the steam iron process. A study of the steam iron process using H2 as reductant focused on the first reduction of 4%Cr203 - 96% Fe203 with H2. The first reduction was found to be composed of a two step reduction up to 550 QC. The estimation of energy of activation for the process was found to be 92.4 KJ/mol and 68.2 KJ/mol respectively. The study of the steam iron process using H2 ICO mixture as reductant over 4%Cr203 - 96% Fe2O3 found that FeO was an intermediate for the reduction of Fe203 with H2ICO mixture to Fe metal. The application of methane as reductant for the steam iron process gave the worst results. As a result, NiO was added to Cr203 -Fe203 to increase the activity. Carbon formation on NiO also was found to be a serious problem. In order to minimize carbon formation on NiO, CO2 was introduced in a mix with CI-4 for the oxidation of deposited carbon during the reduction step. Although the introduction of CO2 can suppress carbon formation, the strong oxidation of reduced iron oxide by water formed during the reduction process coupled to the l1igher favorable reaction of the water gas shift reaction adversely affects the complete reduction of iron oxide to iron metal.
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(2008)ThesisThe effectiveness of location aware applications is dependent on the accuracy of the supporting positioning system. This work evaluates the accuracy of an indoors 802.11 positioning system based on signal strength fingerprinting. The system relies on an empirical survey of signal strength prior to positioning. During this survey, signal strength recordings are made at a set of positions across the environment. These recordings are used as training data for the system during positioning. In this thesis, two surveying methods, five positioning algorithms, and two spatial output averaging methods are trialled. Accuracy is determined by empirical testing in two separate environments: a 100m square domestic house and the 1,333m square third floor of the University of New South Wales Computer Science and Engineering building. In the two environments, the lowest mean distance errors are 1.25m and 2.86m respectively.
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(2008)ThesisObject tracking is an active research topic in computer vision and has appli- cation in several areas, such as event detection and robotics. Vehicle tracking is used in Intelligent Transport System (ITS) and surveillance systems. Its re- liability is critical to the overall performance of these systems. Feature-based methods that are used to represent distinctive content in visual frames are one approach to vehicle tracking. Existing feature-based tracking systems can only track vehicles under ideal conditions. They have difficulties when used under a variety of conditions, for example, during both the day and night. They are highly dependent on stable local features that can be tracked for a long time period. These local features are easily lost because of their local property and image noise caused by factors such as, headlight reflections and sun glare. This thesis presents a new approach, addressing the reliability issues mentioned above, tracking whole feature groups composed of feature points extracted with the Scale Invariant Feature Transform (SIFT) algorithm. A feature group in- cludes several features that share a similar property over a time period and can be tracked to the next frame by tracking individual feature points inside it. It is lost only when all of the features in it are lost in the next frame. We cre- ate these feature groups by clustering individual feature points using distance, velocity and acceleration information between two consecutive frames. These feature groups are then hierarchically clustered by their inter-group distance, velocity and acceleration information. Experimental results show that the pro- posed vehicle tracking system can track vehicles with the average accuracy of over 95%, even when the vehicles have complex motions in noisy scenes. It gen- erally works well even in difficult environments, such as for rainy days, windy days, and at night. We are surprised to find that our tracking system locates and tracks motor bikes and pedestrians. This could open up wider opportunities and further investigation and experiments are required to confirm the tracking performance for these objects. Further work is also required to track more com- plex motions, such as rotation and articulated objects with different motions on different parts.
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(2008)ThesisOver the past two decades, software engineering researchers and practitioners have developed, studied, and used standards and models for software process improvement and assessment. CMMI ("Capability Maturity Model Integration") is a widely known software process maturity model that describes the practices that should be performed by mature organizations. However, there is also no clear mapping between process improvement and business goals, and few authors provide guidance on how to implement the CMMI Specific Practices (SPs) within a Process Area or Maturity Level. This thesis proposes an SP implementation reference model that maps inter-dependent SPs to particular improvement outcomes. The CMMI specification is interpreted using qualitative textual analysis to develop schemes to frame CMMI SPs from the perspectives of outcomes, activities, and work products. The first scheme is an SP classification model, defined by four outcome areas (organization, process, project and product) and four activity groups (plan, do, check and improve). The SPs in Maturity Level 2 are assigned to one or more of sixteen outcome/activity categories and are analyzed in terms of those categories. The second scheme is an SP dependencies model, created by identifying work products used and produced by SPs, and by graphically visualizing their relationships. The SPs in Maturity Level 2 are analysed using the scheme to provide a reference model of their order of implementation, given the identified relationships. The third scheme is a goal-directed SP implementation planning reference model constructed by combining the two earlier schemes. This scheme uses an algorithm to search for all the dependency precedents of SPs in a given outcome/activity category. Conditions are also defined to reduce some of the dependencies. The output shows the SPs required to achieve the goal that the given category represents, and shows the order of implementation for those SPs, respecting the dependency constraints. This model is intended to guide practitioners in prioritizing and sequencing the implementation of SPs. The three schemes contribute to the CMMI research community by increasing understanding about what can be improved by CMMI SPs, with reference to the outcomes of implementing SPs, and about how software processes can be improved using CMMI, with reference to the implementation order of SPs. They also contribute an analytical approach to interpret the practices in SPI specifications. The SP classification model is used to reinterpret previous research to show that SMEs tend to focus on planning and doing project-related and product-related practices, but not on checking or improving project-related or product-related practices. When planning and developing products, SMEs try to ensure that the project progresses as planned to meet the deadline. However, practices that support this are lacking within CMMI, especially for estimation, evaluation, verification, and validation. The thesis also contributes to the CMMI community by identifying points of ambiguity, inconsistency and incompleteness in the CMMI standard.
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(2008)ThesisAn experimental investigation was conducted on the static liquefaction behaviour of very loose lightly cemented sands. Undrained and drained triaxial compression tests, one dimensional consolidation, high stress compression, and unconfined compression tests were performed on artificially prepared lightly cemented loose samples with cement-sand ratios of 2, 4 and 6%. Additional tests were also conducted on uncemented samples prepared at the same initial void ratio as the cemented samples. Besides the influence of degree of cementation, the effects of void ratio and confining pressure on the liquefaction potential of cemented sands were examined. The aim of this study is to make significant contribution to the understanding of static liquefaction failures in lightly cemented sands. It is shown that cementation could increase the initial stiffness and yield strength of cemented sands but its effect might decrease considerably after the peak strength because of destruction of the cementation bond. The response of cemented sands at lower cement contents was very similar to the response of loose sands and behaviour approached the response of medium to dense sands with increase in the degree of cementation. It is also shown that degree of cementation has a significant influence on liquefaction resistance. Even though the presence of small amounts of cementation did not prevent liquefaction failure, the liquefaction resistance of cemented sands generally increased for higher degrees of cementation. The consolidation, high stress compression and unconfined compression tests demonstrated the effect of cementation in increasing both the stiffness and strength of cemented sands. The unconfined compression strength increased approximately linearly with the increase in cement content. The rate of strength gain increased with an increase in the dry density of the compacted sample, indicating that the cementation was more for denser samples.
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(2008)ThesisWines after packaging may undergo microbial spoilage, especially by yeasts. The risk of such spoilage can be minimized by preventing microbial contamination during packaging operations. This thesis describes wine packaging operations and the quality management initiatives required to control microbial contamination during packaging. Control of microbiological quality during packaging needs to be implemented without compromising overall wine quality and its appeal to consumers. The need for rapid, convenient methods to examine yeasts in packaged wine and to assess the hygiene status of wine packaging equipment was identified. The commercially available MicroFoss assay, based on optical measurement of metabolic activity, was evaluated as a rapid method for detecting spoilage yeasts in packaged wine. The method was optimised to enable detection of low levels of yeasts (1 cfu/200 ml of wine), and eliminate interference from wine acidity. More than three hundred wine samples taken immediately after packaging in a large commercial winery were examined for yeasts by the optimized MicroFoss assay and the standard membrane plate culture method. The samples represented red and white wines taken over 15 months and exhibited yeast counts of 0-1 000cfu/200ml. The semi-automated Micro Foss assay reliably detected the presence of yeasts in the samples (correlation coefficient 0.89 with standard method) and gave data within 40 hours. Studies using wines inoculated with pure cultures of specific spoilage yeasts (eg. Zygosaccharomyces bailii) revealed a limitation of MicroFoss in detecting slow growing yeasts. The Biotrace ATP-bioluminescence assay was evaluated as a rapid, convenient method to asses the efficacy of cleaning and sanitation of wine packaging equipment. Approximately 900 samples were examined and met pre-determined assay units as a measure of hygiene status. Data on surface cleanliness were obtained within two minutes. In some samples, residues of biocidal cleaning agents interfered with the assay, giving false positive data.
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(2008)Thesis2-D digital filters have found numerous applications in signal processing and their design is subject to intensive research. In general, these filters are divided into two types: Separable filters as a product of two 1-D filters, and Non-Separable filters. Separable filters are easier to design but work mostly for rectangular-shaped frequency spectrums. On the other hand, non-separable filters are preferred for designing other shapes of spectrum divisions such as diamond-shaped, circular-shaped, fan-shaped, etc. but their design is much more complicated. When designing 2-D filters, there are several important issues which should be considered. These issues are: the accuracy of the pass-band and the transition-band, the pass-band ripple, the stop-band attenuation and the complexity of the filter for its digital implementation. One important class of 2-D filters is the class of 2-D digital filters with Four-Fold symmetry. Despite the fact that these filters can be designed by using some kind of McClellan transform and yet admit fast digital implementation, the shape of their pass-band cannot be easily controlled. The accuracy of the description of the pass-band shape requires a high-order polynomial transformation, but such a transformation leads to the explosive growth of the filter order and its implementation complexity. While there exist some known approaches that can control the pass-band shape more efficiently, they all suffer from the fact that their transition-band should be wide enough to avoid possible singularities that may arise due to the interpolation step. In this study, the semi-definite programming as a tool, is adopted to design non-separable four-fold symmetric 2-D digital filters and it will be shown that unlike previously proposed semi-definite programming based approaches, this approach is advantageous due to the facts that all the filter specifications are met while interpolation is avoided, the dimension of the semi-definite programming formulation is kept moderate, and moreover, the designed filters admit fast digital implementation despite the fact that they are non-separable and are not designed based on 1-D filters. The simulation clearly confirms the viability of this approach. Finally, although only diamond-shaped filters are considered in this study, other filters such as circular-shaped, elliptic-shaped or fan-shaped are expected to be designed in a similar fashion.
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(2008)ThesisLow-swing on-chip interconnect circuits have been viewed as alternative solutions to the problem of delay and power increase of on-chip interconnects. This thesis aims to characterize and optimize several basic low-swing interconnect circuits, by developing simple delay and power estimation methodologies. Accuracies of the proposed methods are validated against SPICE-based simulations on the 90nm technology node. Based on the delay and power estimation methods developed, optimum power-delay trade-off curves are obtained and directly used for comparison among different interconnect circuit strategies. Three low-swing techniques are included, i.e. conventional level converter (CLC), pseudodifferential interconnect circuit (PDIFF), and current-mode signaling (CM). These techniques represent significantly different driver and receiver topologies, where CLC uses lower supply voltage of a normal inverter driver, PDIFF uses NMOS only drivers, while CM has a low impedance termination at the receiving end. In addition, an optimized full-swing repeater-based technique is included as a baseline for comparison. A simplified repeater performance estimation technique considering ramp input signals is also proposed. The most important step in estimating delay of different driver circuits is the accurate estimation of transistor effective resistance, which considers velocity saturation effects and voltage transition patterns. Optimization for the CM circuit for on-chip interconnects requires completely different treatment than the voltage-mode circuits, due to the different and more complex effective driver resistance and termination resistance modeling. Sizing the driver and receiver transistors should be done simultaneously as their resistive values which affect its performance are dependent on each other. Optimum transistor sizing is very dependent on the required voltage swing chosen. Results of our comparisons show that optimized CLC (reduced voltage supply) repeaters appears to give the best general performance with a slight delay overhead compared to full-swing repeaters. The fact that CLC with repeaters has shorter delay than single-segment CM and PDIFF highlights the effectiveness of repeater structures in long wires. The inclusion of inductance and closed-form solutions to derive optimum transistor sizings for various low-swing interconnect circuits may be developed as a future work using delay and power estimation models presented in this thesis, which is a challenging task to do considering the non-linear equations involved.
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(2008)ThesisBackground: The molecular and cellular mechanisms corresponding to the compensatory and maladaptive hypertrophy and remodeling of the left ventricle with chronic doxorubicin (DOX) treatment are currently unclear. Non-invasive methods of determining these changes are still deficient. To investigate these changes, 8 groups of rats in 4 different studies including a control saline group of the same age, gender and strain were evaluated for cardiac morphology and function including: (1) DOX dose response using a cumulative dose of 7.5mg/kg, and 15mg/kg in 8-10 week old female Sprague-Dawley (SD) rats, (2) strain differences were investigated in response to a cumulative dose of 15mg/kg in 8-10 week old female Fisher (F344) rats compared to the SD rats treated with same dose, (3) the role of gender and aging were studied in response to DOX at a cumulative dose of 3mg/kg in male and female neonates, and (4) combined losartan and a cumulative dose of 15mg/kg of DOX in 8-10 week old female SD rats compared to controls of saline and 15mg/kg treated SD rats. Method: Onset of cardiac toxicity was assessed by echocardiography and the rat model of heart failure was developed when the fractional shortening declined ≤ 40%. The mean arterial pressure and single-photon-emission computer tomography scanning and Tc-99m-HYNIC-Annexin V were performed at week 10 to analyze blood pressure and quantify apoptosis, respectively. All rats were euthanized at week 10 except for the neonates and two of the 7.5mg/kg-treated SD rats that were left alive for study of long -term cardiac side effects. The heart and kidney tissues were harvested for protein isolation and histopathological studies. Blood samples were collected for hematological and lipid profile analysis in all the rats. Results: A dose- and time-dependent increase in LVmass coincided with a parallel increase in MAP, kidney damage, expression of myocardial erbB2, heat shock protein 90 Akt, mTOR, GSK-3β, TGF-β, pSMAD2, and cardiomyocyte apoptosis in SD rats treated with 7.5mg/kg and 15mg/kg of DOX at week 10. The 7.5 kg/kg treatment showed adaptive hypertrophy whereas the 15mg/kg treatment group showed maladaptive hypertrophy. However decompensation was apparent by week 14 in other rats treated with 7.5mg/kg. LVmass, FS, MAP, kidney damage, red blood cells and blood lipid levels were not significantly altered in the F344 rats compared to the 15 mg/kg-treated SD rats. Losartan supplementation reduced the left ventricular hypertrophy, improved myocardial contractility, and reduced TGF-β expression compared to the DOX-treated SD rats. The 3mg/kg of DOX in neonates induced cardiac toxicity and deaths in about 60% of males 50 weeks after treatment; the females instead developed mammary tumors. Conclusion: The results of this study suggest that age, gender, and strain differences are risks factors for doxorubicin-induced harmful reno-cardiovascular toxicity. The inhibition of TGF-β expression by losartan can be used in prevention of chronic doxorubicin-induced cardiac toxicity without interfering with its anti-tumor activities.
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(2008)ThesisPerlecan is an important basement membrane heparan sulfate (HS) proteoglycan that is essential for various cell signaling events involved in tissue development. Heparanase is a lysosomal enzyme involved in the turnover of HS. This project aimed to assist in researching the structure of HS on perlecan and how this structure changes with tissue development. This will be achieved by generating monoclonal antibodies that have an altered affinity for perlecan after heparanase treatment. Recombinant perlecan domain I was characterized by ELISA and western blotting and used as the antigen for two fusions. The first fusion was focused on the production of IgM the common subtype of anti-glycosaminoglycans antibodies. However, no clones were produced, which may have been due to the lack of feeder layers. In order to address this problem, the fibroblast cell line MRC-5 was used as a feeder layer in the second fusion. From this fusion, we obtained 216 positive cultures, which were screened against full length perlecan from endothelial cells. Of these, 26 cultures were tested against heparanase treated perlecan, and then 2 cultures were chosen for subcloning based on the different immunoreactivity between enzyme treated and nontreated perlecan. From the 2 chosen cultures, 13 sub clones were derived and 10 of them were adapted into a serum free culture environment. The 10 monoclonal antibodies displayed strong immunoreactivity with full length perlecan in ELISA and Western Blotting. When they were used as primary antibodies in Immunocytochemistry, they were able to recognize the native perlecan deposited by human chondrocytes. When the cells were incubated with heparanase, antibody 5D7-2E4 and 13E9-3G5 showed an increase in immunoreactivity while antibody 13E9-3B3 gave a decrease. These three antibodies will be the potential tools used in the future to study perlecan turnover in different cells and tissue. The remaining seven antibodies will also be very useful in the research of perlecan as they have been shown to bind to the protein core. In the future, it will be worth subcloning some of the frozen stored stocks of uncloned hybridomas, where there are potential opportunities to select antibodies, which will react with the carbohydrate chains on perlecan.