Дисертації з теми "Watersheds Australia Mathematical models"
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1
Mercurio, Matthew Forrest. "Divider analysis of drainage divides delineated at the field scale." Virtual Press, 2004. http://liblink.bsu.edu/uhtbin/catkey/1306855.
Повний текст джерелаАнотація:
Previous works have applied the Divider Method to the shapes of drainage divides as measured from maps. This study focuses on the shapes of several drainage divides measured in the field at very fine scale. These divides, chosen for their sharp crests, include portions of the Continental Divide in Colorado and badlands-type divides in Arizona, Wyoming, South Dakota, and Texas. The badlands type divides were delineated using a laser theodolite to collect data at decimeter point spacing, and the Continental Divide segments were delineated using pace and bearing at a constant point spacing of 30 meters. A GIS was used to store and visualize the divide data, and an automated divider analysis was performed for each of the 16 drainage divides.The Richardson plots produced for each of the drainage divide datasets were visually inspected for portions of linearity. Fractal dimensions (D) were calculated using linear regression techniques for each of the linear segments identified in the Richardson plots. Six of the plots exhibited two distinct segments of linearity, nine plots exhibited one segment, and one plot exhibited no segments of linearity. Residual analyses of the trend lines show that about half of the Richardson plot segments used to calculate D exhibit slight curvature. While these segments are not strictly linear, linear models and associated D values may still serve well as approximations to describe degree of divide wandering.Most (20 out of 21) of the dimensions derived from the Richardson plots for the drainage divides fall within the range from 1.01-1.07. The D values calculated for the Continental Divide range from 1.02-1.07. The dimensions calculated for the badlandtype divides were distributed evenly across the range of 1.01-1.06, with a single exceptional D value at 1.12. Only four of the divide D values fall within a range of 1.06–1.12, the range for D established for drainage divides in published map-based studies, despite the apparent dominance of erosion processes on the measured divides.Department of Geology
2
Balakrishnan, Aneesha B. "Comparative complexity of continental divides on five continents." CardinalScholar 1.0, 2010. http://liblink.bsu.edu/uhtbin/catkey/1562866.
Повний текст джерелаАнотація:
The main focus of the present study is to identify and integrate the factors affecting the degree of irregularity of five continental divide traces, as expressed by their fractal characteristics measured by the divider method. The factors studied are climate, relief and tectonic environment. The second objective of this study is to determine the relationship between uplift rates and divide trace fractal dimension.
Analysis of the results suggests that the degree of irregularity of continental divide traces at fine scale (approximately 10-70 km of resolution) is strongly affected by both climate and tectonics. It is found that control of the factors is generally weaker at coarse scale (above approximately 70 km of resolution). Generic relief should be ranked below both climate and tectonic environment as a factor affecting the complexity of continental divide traces. In terms of the second objective, the fractal dimension at fine scales follows a weakly inverse relationship with uplift. At coarse scale, there is stronger inverse relationship between uplift rate and fractal dimension.Introduction -- Methodology -- Geomorphic environment -- Evaluation of results -- Significance of control factors -- Conclusion.
Department of Geological Sciences
3
Washburne, James Clarke. "A distributed surface temperature and energy balance model of a semi-arid watershed." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186800.
Повний текст джерелаАнотація:
A simple model of surface and sub-surface soil temperature was developed at the watershed scale (-100 km²) in a semi-arid rangeland environment. The model consisted of a linear combination of air temperature and net radiation and assumed: (1) topography controls the spatial distribution of net radiation, (2) near-surface air temperature and incoming solar radiation are relatively homogeneous at the watershed scale and are available from ground stations and (3) soil moisture dominates transient soil thermal property variability. Multiplicative constants were defined to account for clear sky diffuse radiation, soil thermal inertia, an initially fixed ratio between soil heat flux and net radiation and exponential attenuation of solar radiation through a partial canopy. The surface temperature can optionally be adjusted for temperature and emissivity differences between mixed bare soil and vegetation canopies. Model development stressed physical simplicity and commonly available spatial and temporal data sets. Slowly varying surface characteristics, such as albedo, vegetation density and topography were derived from a series of Landsat TM images and a 7.5" USGS digital elevation model at a spatial resolution of 30 m. Diurnally variable atmospheric parameters were derived from a pair of ground meteorological stations using 30-60 min averages. One site was used to drive the model, the other served as a control to estimate model error. Data collected as part of the Monsoon '90 and WG '92 field experiments over the ARS Walnut Gulch Experimental Watershed in SE Arizona were used to validate and test the model. Point, transect and spatially distributed values of modeled surface temperature were compared with synchronous ground, aircraft and satellite thermal measurements. There was little difference between ground and aircraft measurements of surface reflectance and temperature which makes aircraft transects the preferred method to "ground truth" satellite observations. Mid-morning modeled surface temperatures were within 2° C of observed values at all but satellite scales, where atmospheric water vapor corrections complicate the determination of accurate temperatures. The utility of satellite thermal measurements and models to study various ground phenomena (e.g. soil thermal inertia and surface energy balance) were investigated. Soil moisture anomalies were detectable, but were more likely associated with average near-surface soil moisture levels than individual storm footprints.
4
Mtundu, Nangantani Davies Godfrey. "The Stochastic Behavior of Soil Moisture and Its Role in Catchment Response Models." PDXScholar, 1987. https://pdxscholar.library.pdx.edu/open_access_etds/527.
Повний текст джерелаАнотація:
The object of current efforts at investigating catchment response is to derive a physically based stochastic model of the watershed. Recent studies have, however, indicated that a limiting factor in deriving such models is the dependence of hydrologic response on initial soil moisture. The dependence affects the distributions and moments of the hydrological processes being investigated. A stochastic model of soil moisture dynamics is developed in the form of a pair of stochastic differential equations (SDE's) of the Ito type. The sources of stochasticity are linked to the random inputs of rainfall and evapotranspiration (ET). One of the SDE's describes the "surplus" case, in which sufficient infiltration always occurs to allow for moisture depletion by the processes of drainage through and ET out of the root zone. The other SDE represents the "deficit" case, in which lack of adequate moisture leads only to an ET-controlled depletion process. Sample functions and moments of moisture evolution are obtained from the SDE's. From the general model of soil moisture, a specific model of initial soil moisture (the moisture at the beginning of a rainstorm event) is developed and its moments are derived. Furthermore, the probability distribution of initial moisture is postulated to permit the assessment of how initial moisture affects the estimation of hydrologic response. The moisture dynamics model reveals that the stochastic properties of moisture ae sensitive to initial conditions in the watershed only for less permeable soils under the "surplus" state but are practically insensitive to such conditions for more permeable soils. The stochastic properties are also less sensitive to initial conditions for all soil types whenever under the "deficit" state. These results suggest that hydrologic processes, such as precipitation excess and infiltration, depend on initial moisture only in regions where the soils are generally less permeable and where the climate tends to sustain a "wet" environment, whereas in arid or semi-arid regions, such processes would not depend on initial moisture. These conclusions imply that, in arid regions, an effective value of initial moisture such as the mean can be used to estimate the properties of the hydrologic processes, whereas in "wet" environments, more accurate values of the properties must be "weighted" based on the probability distribution of initial soil moisture.
5
Enright, Peter 1962. "Simulation of rainfall excess on flat rural watersheds in Quebec." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61952.
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6
Powell, Robert. "Industry value at risk in Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2007. https://ro.ecu.edu.au/theses/297.
Повний текст джерелаАнотація:
Value at Risk (VaR) models have gained increasing momentum in recent years. Market VaR is an important issue for banks since its adoption as a primary risk metric in the Basel Accords and the requirement that it is calculated on a daily basis. Credit risk modelling has become increasingly important to banks since the advent of Basel 11 which allows banks with sophisticated modelling techniques to use internal models for the purpose of calculating capital requirements. A high level of credit risk is often the key reason behind banks failing or experiencing severe difficulty. Conditional Value at Risk (CVaR) measures extreme risk, and is gaining popularity with the recognition that high losses are often impacted by a small number of extreme events.
7
Xu, Qian, and 徐倩. "Field investigation and numerical modeling of hydrological processes at a hillslope catchment in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196019.
Повний текст джерелаАнотація:
Motivated by mitigating flash flood-related damages, this study conducts a comprehensive exploration of hillslope hydrological processes, which includes data collection and experimental measurement, analysis of the rainfall-runoff features and modeling hydrological processes. To study the temporal and spatial variation of TF (throughfall), rainfall data recorded at eight rain gauges near and under a 6-m-tall multiple-layer deciduous tree (Macaranga tanarius) are analyzed. This study reveals that the leaf convergence and divergence can significantly influence TF temporal and spatial variations. For some rain gauges, the TF values can be larger than the GR (gross rainfall) for 30% of total rainfall events.
Using three classical baseflow separation methods (namely, the straight line method, inflection point method and one parameter filter method), this study computes the direct runoff volumes for 24 storms. Their runoff coefficients (which are the ratios of direct runoff volumes to the total rainfall volumes) are obtained. The analysis indicates that direct runoffs can contribute about 82% of flood peak discharges, but the average runoff coefficients are less than 4%.
To make use of the observed hydrological data, a numerical model, TOPMODEL, is used to simulate the hydrological processes. Further, to determine the model parameters, several field surveys have been conducted to collect land cover, soil properties, and hydraulic features of the catchment. Model parameters for the catchment are calibrated using a global optimization method, namely the SCE-UA (shuffled complex evolution-The University of Arizona), and Nash-Sutcliffe efficiency (E) as the objective function. To enhance TOPMODEL, this study confirms that the interflow process is important in improving runoff simulation.published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
8
Small, Aaron Brent. "A comparative evaluation of surface runoff models and methods on small developing watersheds in Northern Virginia." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03302010-020635/.
Повний текст джерелаАнотація:
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993.18 color maps in back pocket. Vita. Abstract. Includes bibliographical references (leaves 137-139). Also available via the Internet.
9
Jaforullah, Mohammad. "Energy modelling in a general equilibrium framework with alternative production specifications." Title page, contents and astract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phj23.pdf.
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10
Du, Yi. "Implementation of a Wetting and Drying Model in Simulating the Androscoggin/Kennebec Plume and the Circulation in Casco Bay." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/DuY2008.pdf.
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Perrone, Jim T. "Hydrologic modeling of an agricultural watershed in Quebec using AGNPS." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29763.pdf.
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Wildegger-Gaissmaier, Anna Elisabeth. "Fluidized bed utilization of South Australian coals." Title page, contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phw672.pdf.
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Gao, Zhanhai School of Mathematics UNSW. "Modelling Human Immunodeficiency Virus and Hepatitis C Virus Epidemics in Australia." Awarded by:University of New South Wales. School of Mathematics, 2001. http://handle.unsw.edu.au/1959.4/18187.
Повний текст джерелаАнотація:
This thesis is concerned with the mathematical modelling for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) epidemics in Australia. There are two parts to this thesis. Part I is aimed at modelling the transmission of HIV and HCV via needle sharing among injecting drug users (IDUs). The dynamical model of an epidemic through needle sharing among IDUs is derived. This model reveals the correlation between needle sharing and the epidemic prevalence among IDUs. The simulations of HIV and HCV prevalence and incidence among IDUs in Australia are made with this model. The comparison of simulated results with literature estimates shows that the modelled results are consistent with the literature estimates. The effects of needle sharing and cleaning on HIV and HCV prevalence and incidence among IDUs in Australia are evaluated. Part II is devoted to modelling the spread of HIV in the general community in Australia. A mathematical model is formulated to assess the epidemiological consequences of injecting drug use and sexual transmission in Australia. The effects of highly active antiretroviral therapies (HAART) on the HIV epidemic are included. The modelled results are in broad agreement with the literature estimates and observed data. The long-term effects of HAART are also discussed.
14
Lee, Haksu. "Development and performance analysis of a physically based hydrological model incorporating the effects of subgrid heterogeneity." University of Western Australia. School of Environmental Systems Engineering, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0129.
Повний текст джерелаАнотація:
[Truncated abstract] The balance equations of mass and momentum, defined at the scale of what has been defined as a Representative Elementary Watershed (REW) has been proposed by Reggiani et al. (1998, 1999). While it has been acknowledged that the REW approach and the associated balance equations can be the basis for the development of a new generation of distributed physically based hydrological models, four building blocks have been identified as necessary to transform the REW approach into, at the very least least, a workable modelling framework beyond the theoretical achievements. These are: 1) the development of reasonable closure relations for the mass exchange fluxes within and between various REW sub-regions that effectively parameterize the effects of sub-REW heterogeneity of climatic and landscape properties, 2) the design of numerical algorithms capable of generating numerical solutions of the REW-scale balance equations composed of a set of coupled ordinary differential and algebraic equations for the number of REWs constituting a study catchment and the sub-regions within the REWs, 3) applications of the resulting numerical model to real catchments to assess its performance in the prediction of any specified hydrological variables, and 4) the assessment of the model reliability through estimation of model predictive uncertainty and parameter uncertainty. This thesis is aimed at making substantial progress in developing each of these building blocks. Chapter 1 presents the background and motivation for the thesis, while Chapter 2 summarizes its main contributions. Chapter 3 presents a description of the closure problem that the REW approach faces, and presents and implements various approaches to develop closure relations needed for the completeness of balance equations of the REW approach. ... In addition, Chapter 4 also shows an initial application of CREW to a small catchment, Susannah Brook in the south-west of Western Australia. Chapter 5 presents the application of CREW to two meso-scale catchments in Australia, namely Collie and Howard Springs, located in contrasting climates. Chapter 6 presents results of the estimation of predictive uncertainty and parameter sensitivity through the application of CREW to two catchments in Australia, namely Susannah Brook and Howard Springs, by using the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. Finally, Chapter 7 presents recommendations for future work for the further advancement of the REW approach. Through these exercises this PhD thesis has successfully transformed the REW-scale coupled balance equations derived by Reggiani et al. (1998, 1999) into a new, well tested numerical model blueprint for the development and implementation of distributed, physically based models applicable at the catchment, or REW scale.
15
Soucik, Victor. "Finding the true performance of Australian managed funds." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2002. https://ro.ecu.edu.au/theses/730.
Повний текст джерелаАнотація:
When making conclusions about the performance of managed funds, it is critical that the framework in which such performance is measured provides an accurate and unbiased environment. In this thesis I search for true performance of the two major classes of funds- equity as well as fixed interest managed funds. Focusing, first on the former class, I examine five measurement models across three risk-free proxies, nine benchmarks proposed by the extant literature (covering conditional and unconditional as well as single and multi factor definitions) and over three independent periods in an effort to identity (in a consistent setting) the most accurate and least biast methodology. I also use the Australian dataset, which inherently mitigates any data biases that may potentially afflict US studies of these methodologies, since these were developed from the same dataset on which they were later tested. Not finding a pre-existing benchmark that is objective yet informative, I develop an independent model that satisfies these, sourcing from fifteen factor candidates across four categories. I find that teaming up a fund based market factor with well-defined proxies for size, value, momentum and conditional dividend yield provides the optimal benchmark. The latter class comprising fixed-interest managed funds is a segment left largely unexplored in the financial literature and neglected outright in the Australian context. I examine three risk-free proxies, six benchmark classes encompassing twenty-one potential factors, across five models and two independent time frames in an effort to establish the most informative and least biased setting. The task is complicated by two issues - an acute lack of Australian data (demanding additional bootstrap simulations and bridging tests with the US markets) and the need for a two-pass (time-series and cross-sectional) analysis, arising from the different information content benchmarks carry in these two dimensions. My results, consistent across time, show that a correct combination of a bond market variable, a mixture of interest rate factors and economic factors as well as the proxy for movements in the equity markets yield the optimal benchmark. Both fund classes point to Jensen's Alpha as the preferred model, but Treynor and Mazuy's definition of a quadratic measure is adequate if timing-selectivity separation is required. Neither class is significantly sensitive to the choice of risk free proxy featuring in the performance measures.
16
Dennis, Kevin. "A mathematical model to describe haemophilus influenzae type B within Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1995. https://ro.ecu.edu.au/theses/1160.
Повний текст джерелаАнотація:
This work is primarily aimed at determining the effect that an immunisation policy Is likely to have on the incidence of Haemophllus influenzae Type B (HIB) and systematic HIB in Western Australia. There was a significant effort made to collect data pertinent to the estimation of parameter values but since HIB has only been a notifiable disease since 1992, there was a distinct lack of relevant data available. Private communication with individual’s such as Dr Jeffrey Hanna and Dr Beryl Wild resulted in practical information being obtained that was used to estimate certain parameters. The deterministic mathematical models within the thesis are extensions of existing ideas tailored to suit the needs of this thesis. Chapter one is a basic introduction to the pursuit of modelling infectious diseases with a brief description of basic epidemiology concepts. It also shows that even simple models may not deliver analytical results. Chapter two extends a model used by Angela Mclean and allows some analytical results to be obtained by first simplifying the model and then solving using standard methods to give the equilibrium distributions for the proportions of people in each state within the model
17
Ernst, Wolfgang F. "The economic rationale for stochastic urban transport models and travel behaviour : a mathematical programming approach to quantitative analysis with Perth data." UWA Business School, 2003. http://theses.library.uwa.edu.au/adt-WU2005.0004.
Повний текст джерелаАнотація:
[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] This thesis reviews, extends and applies to urban traffic analysis the entropy concept of Shannon and Luce's mathematical psychology in a fairly complex and mathematically demanding model of human decision making, if it is solved as a deeply nested structure of logit calculus. Recognising consumers' different preferences and the universal propensity to seek the best choice when going to some desired goal (k), a transparent mathematical program (MP) is developed: the equivalent of a nested multinomial logit model without its inherent computational difficulty. The MP model makes a statistical assessment of individual decisions based on a randomised (measurable) utility within a given choice structure: some path through a diagram (Rk, Dk), designed a priori, of a finite number of sequential choices. The Equivalence Theorem (ET) formalises the process and states a non-linear MP with linear constraints that maximises collective satisfaction: utility plus weighted entropy, where the weight (1/θn) is a behavioural parameter to be calibrated in each case, eg for the Perth CBD. An optimisation subject to feasible routes through the (Rk, Dk) network thus captures the rational behaviour of consumers on their individually different best-choice decision paths towards their respective goals (k). This theory has been applied to urban traffic assignment before: a Stochastic User Equi-librium (SUE). What sets this thesis apart is its focus on MP models that can be solved with standard Operations Research software (eg MINOS), models for which the ET is a conditio sine qua non. A brief list of SUE examples in the literature includes Fisk's logit SUE model in (impractically many) route flows. Dial's STOCH algorithm obviates path enumeration, yet is a logit multi-path assignment procedure, not an MP model; it is nei-ther destination oriented nor an optimisation towards a SUE. A revision of Dial's method is provided, named STOCH[k], that computes primal variables (node and link flows) and Lagrangian duals (the satisfaction difference n→k). Sheffi & Powell presented an unconstrained optimisation problem, but favoured a probit SUE, defying closed formulae and standard OR software. Their model corresponds to the (constrained) dual model here, yet the specifics of our primary MP model and its dual are possible only if one restricts himself to logit SUE models, including the ET, which is logit-specific. A real world application needs decomposition, and the Perth CBD example is iteratively solved by Partial Linearisation, switching from (measured) disutility minimisation to Sheffi & Powell's Method of Successive Averages near the optimum. The methodology is demonstrated on the Perth Central Business District (CBD). To that end, parameter Θ is calibrated on Main Roads' traffic count data over the years 1997/98 and 1998/99. The method is a revision of Liu & Fricker's simultaneous estimation of not only Θ but an appropriate trip matrix also. Our method handles the more difficult variable costs (congestion), incomplete data (missing observations) and observation errors (wrong data). Finally, again based on Main Roads' data (a sub-area trip matrix), a Perth CBD traffic assignment is computed, (a) as a logit SUE and - for comparison - (b) as a DUE (using the PARTAN method of Florian, Guélat and Spiess). The results are only superficially similar. In conclusion, the methodology has the potential to replace current DUE models and to deepen transport policy analysis, taking into account individual behaviour and a money-metric utility that quantifies 'social benefits', for instance in a cost-benefit-analysis.
18
O???Brien, Peter Banking & Finance Australian School of Business UNSW. "Term structure modelling and the dynamics of Australian interest rates." Awarded by:University of New South Wales. School of Banking and Finance, 2006. http://handle.unsw.edu.au/1959.4/28283.
Повний текст джерелаАнотація:
This thesis consists of two related parts. In the first part we conduct an empirical examination of the dynamics of Australian interest rates of six different maturities, covering the whole yield curve. This direct study of the long rates is quite novel. We use maximum likelihood estimation on a variety of models and find some results that are in stark contrast to previous studies. We estimate Poisson-jump diffusion (PJD) models and find very strong evidence for the existence of jumps in all daily interest rate series. We find that the PJD model fits short-rate data significantly better than a Bernoulli-jump diffusion model. We also estimate the CKLS model for our data and find that the only model not rejected for all six maturities is the CEV model in stark contrast to previous findings. Also, we find that the elasticity of variance estimate in the CKLS model is much higher for the short-rates than for the longer rates where the estimate is only about 0.25, indicating that different dynamics seem to be at work for different maturities. We also found that adding jumps to the simple diffusion model gives a larger improvement than comes from going from the simple diffusion to the CKLS model. In the second part of the thesis we examine the Flesaker and Hughston (FH) term structure model. We derive the dynamics of the short rate under both the original measure and the risk-neutral measure, and show that some criticisms of the bounds for the short rate may not be significant in actual applications. We also derive the dynamics of bond prices in the FH model and compare them to the HJM model. We also extend the FH model by allowing the martingale to follow a jump-diffusion process, rather than just a diffusion process. We derive the unique change of measure that guarantees the family of bond prices is arbitrage-free. We derive prices for caps and swaptions, and extend the results to include Bermudan swaptions and show how to price options with the jump-diffusion version of the FH model.
19
Carter, Robert C. (Robert Charles) 1950. "The macro economic evaluation model (MEEM) : an approach to priority setting in the health sector." Monash University, Dept. of Management, 2001. http://arrow.monash.edu.au/hdl/1959.1/8672.
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20
Goodrich, David Charles. "Geometric simplification of a distributed rainfall-runoff model over a range of basin scales." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185051.
Повний текст джерелаАнотація:
Distributed rainfall-runoff models are gaining widespread acceptance; yet, a fundamental issue that must be addressed by all users of these models is definition of an acceptable level of watershed discretization (geometric model complexity). The level of geometric model complexity is a function of basin and climatic scales as well as the availability of input and verification data. Equilibrium discharge storage is employed to develop a quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance. Equilibrium storage ratios are used to define the transition from overland to channel-dominated flow response. The methodology is tested on four subcatchments in the USDA-ARS Walnut Gulch Experimental Watershed in southeastern Arizona. The catchments cover a range of basins scales of over three orders of magnitude. This enabled a unique assessment of watershed response behavior as a function of basin scale. High quality, distributed, rainfall-runoff data were used to verify the model (KINEROSR). Excellent calibration and verification results provided confidence in subsequent model interpretations regarding watershed response behavior. An average elementary channel support area of roughly 15% of the total basin area is shown to provide a watershed discretization level that maintains model performance for basins ranging in size from 1.5 to 631 hectares. Detailed examination of infiltration, including the role and impacts of incorporating small-scale infiltration variability in a distribution sense, into KINEROSR, over a range of soils and climatic scales was also addressed. The impacts of infiltration and channel losses on runoff response increase with increasing watershed scale as the relative influence of storms is diminished in a semi-arid environment such as Walnut Gulch. In this semi-arid environment, characterized by ephemeral streams, watershed runoff response does not become more linear with increasing watershed scale but appears to become more nonlinear.
21
Kirkpatrick, Raelene. "A mathematical analysis of the financial and medical impact of hepatitis C among drug users in Perth, Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2003. https://ro.ecu.edu.au/theses/1332.
Повний текст джерелаАнотація:
The ability of public health planners continues to be hampered by uncertainties encountered with transmissible diseases. Key epidemiological factors such as, how many Western Australian injecting drug users are hepatitis C seropositive or will become infected, duration of intravenous drug use, the intensity of infection, the fraction of those infected that will develop end-stage disease and after how long a period, all combine to limit the ability of a mathematical model to predict future trends. These models can, however, provide information about certain epidemiological parameters and identify data required to predict future trends. They can be applied to make predictions about the course of infection in the individual and provide a guide to the interpretation of the observed data. This research aims to develop a model of the transmission and spread of hepatitis C, adapting existing models used to predict the spread of HIV and AIDS in one and two sex communities. This model will be used to demonstrate the dynamics and incidence of hepatitis C infection among injecting drug users in Perth, Western Australia. Predictions derived from the model will then be used to undertake an analysis of the cost of treating those with hepatitis C and cirrhosis related complications, resulting in a prediction of the financial impact of hepatitis C on the Western Australian community.
22
Odeh, Inakwu Ominyi Akots. "Soil pattern recognition in a South Australian subcatchment /." Title page, contents and abstract only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09pho23.pdf.
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Kwok, Ho King Calvin Actuarial Studies Australian School of Business UNSW. "Energy price modelling and risk management." Awarded by:University of New South Wales. Actuarial Studies, 2007. http://handle.unsw.edu.au/1959.4/40602.
Повний текст джерелаАнотація:
This thesis focuses on the development of a forecasting model for short- to medium-term electricity spot prices, based on modelling the dynamics of the supply and demand functions. It is found that the equilibrium assumption frequently adopted in electricity price models does not always hold; to overcome this problem, a notional demand process derived from the market clearing condition is proposed. Not only is this demand process able to capture all the price-affecting factors in one variable, but it also allows the equilibrium assumption to be satisfied and a spot price model to be built, using any appropriate form of hypothetical supply function. In addition, this thesis presents a model for approximating and modelling the bid stacks by capturing the points that govern their shape and location. Integrating these two models provides a realistic model that has a mean absolute percentage error of approximately 19% and 24% for week- and month-ahead forecasts respectively, when applied to the New South Wales (NSW) half-hourly electricity spot prices. Additionally, the density forecasting evaluation method proposed by Diebold et al. (1998) is employed in the thesis to assess the performance of the model. Besides the development of a spot price model, a two-part empirical study is made of the prices of NSW electricity futures contracts. The first part of the study develops a method based on the principle of certainty equivalence, which enables the market utility function to be recovered from a set of futures market quotes. The method is tested with two different sets of simulated data and works as expected. However, it is unable to obtain useful results from the NSW market quotes due to the poor data quality. The second part uses a regression method to investigate the relationship between futures prices and the descriptive statistics of the underlying spot prices. The result suggests that futures prices in NSW are linear combinations of the median and volatility of the final payoff.
24
Thein, Hla-Hla Public Health & Community Medicine Faculty of Medicine UNSW. "Measuring the health burden of hepatitis C at an individual and population level in Australia." Awarded by:University of New South Wales. School of Public Health and Community Medicine, 2006. http://handle.unsw.edu.au/1959.4/24967.
Повний текст джерелаАнотація:
This thesis examines the effect of hepatitis C virus infection (HCV) on health-related quality of life (HRQOL) to define burden of disease at individual and population levels. A systematic review of HCV HRQOL studies was undertaken with translation of Short Form-36 (SF-36) Health Survey data into community-weighted health state utilities using three different methods. Derived estimates of health utilities were 0.87 for HCV treatment-induced sustained virological response (SVR); 0.81 for pre-cirrhosis; 0.76 for compensated cirrhosis; 0.69 for decompensated cirrhosis; 0.67 for hepatocellular carcinoma (HCC); and 0.77 for liver transplant. The HCV health state utilities varied considerably from expert estimates, with relatively lower estimates for early liver disease and higher estimates for advanced liver disease, but were comparable to direct patient-elicited utilities. A study utilising data from population-based health surveys incorporating HCV screening among prisoners at Australian correctional centres in 1996 and 2001 showed no measurable effect of HCV on HRQOL, including that attributable to HCV viraemia. Compared to uninfected Australian norms, prisoners had lower HRQOL irrespective of HCV status. Several non-HCV factors such as age, co-morbidity, severity of depressive symptoms, and medical care utilization influenced HRQOL. A prospective study of health outcomes among HCV monoinfected and HIV/HCV coinfected individuals conducted at Sydney tertiary level hepatitis clinics between 2003 and 2005 found similar cognitive function, mood, and HRQOL patterns in these two HCV groups in the context of pegylated interferon (PEG-IFN) alfa-2a and ribavirin therapy. The HCV groups had similar levels of pre-treatment HRQOL impairment, further on-treatment deterioration, and posttreatment improvements. SVR was associated with significant HRQOL improvements, but mental HRQOL improvement was also seen in individuals not achieving an SVR. The impact of HCV treatment uptake on HCV-related burden of disease at a population level in Australia was examined using a mathematical model. The model estimated that in 2004, there were ~181,500 cases of chronic HCV infection, 7,020 with HCV-related cirrhosis, and annual incidence of 238 cases of HCV-related liver failure and 70 cases of HCV-related HCC. Compared to no treatment, current treatment levels (~1% of HCV-infected individuals per annum) would reduce projected HCV-related cirrhosis and advanced liver disease numbers by ~30% at 2020 and a gain of ~122,200 Quality-Adjusted Life Years (QALYs). Even with a five-fold increase from current treatment levels, advanced liver disease numbers will continue to increase through 2020 but will be reduced by ~55% and a gain of ~483,200 QALYs.
25
Price, Myra Ann. "Seasonal Variation in Runoff Curve Number." Thesis, The University of Arizona, 1998. http://hdl.handle.net/10150/225411.
Повний текст джерелаАнотація:
The seasonal variation in rainfall - runoff response is investigated for about 300 small watersheds throughout the United States. Data from USDA research watersheds were used to define runoff Curve Number for ordered data sets by months. Three major patterns of cyclic variation are found and investigated: 1) distinct and well - defined seasonal variations as typified by forested watersheds in heavy rainfall zones; 2) mildly cyclic variation found typically in meadows and grasslands, and 3) non - cyclic or unidentifiable patterns, including those with insufficient seasonal data. The only pattern that may be present is the well-defined seasonal variation found so far only in forested watersheds. Regional characteristics were found for individual crop types. For the watersheds studied there seemed to be no difference in the variation between crops except for meadow during the summer. Some associated background factors are explored, including long-term and short-term antecedent rainfall.
26
Fiorentino, Francesca. "Mathematical models of the impact of rabbit calicivirus disease (RCD) on the European rabbit, Oryctolagus cuniculus, in Australia." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446810/.
Повний текст джерелаАнотація:
This thesis relates to the work of building a mathematical model of the impact of Rabbit Calicivirus Disease (RCD) on the European Rabbit, Oryctolagus cuniculus, in Australia. After introducing the general biology of rabbits and the immunology of RCD, we build a time-dependent single site model. We construct a single-site population dynamic model with age structure, seasonal birth rate, density dependent regulation of the population size and climatic variability for various regions of Australia. After investigating suitable parameter ranges, we incorporate the disease dynamics through an indirect transmission model based on two different hypotheses which we call the Strong Juvenile hypothesis and the Weak Juvenile hypothesis. These differ in their assumption about Juvenile immunity to the disease. The ecological impact of both hypotheses is tested for both the single site and multiple site (spatial) models. The disease impact is investigated by varying the disease virulence, i.e. a parameter measuring the "strength" of the virus. Subsequently, a multiple site (spatial) model for the Riverina region is built by using the single-site model as building block. Data from Lake Urana is used to parameterize a seasonal emigration rate from each site. Density dependent immigration is added together with a hazard coefficient which rabbits face when leaving one site and trying to become established in another. Acceptance in a new site is regulated by the population density at the entry site. Several spatial configurations of sites are tested and the spatial dynamics of the disease is investigated. Finally, we construct a model to investigate the long term evolution of the disease virus. We postulate the existence of several strains of the disease and trade-offs between disease characteristics. We allow for mutation of the virus and run the model for two contrasting geographical regions of Australia. We compare the results for the different regions and the different hypotheses regarding Juvenile immunity (the Strong Juvenile hypothesis and the Weak Juvenile hypothesis). It is shown, unexpectedly, that intermediate levels of disease virulence are not selected.
27
Farag, Saarah A. "A comparison of advanced time series models for environmental dependent stock recruitment of the western rock lobster." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1998. https://ro.ecu.edu.au/theses/997.
Повний текст джерелаАнотація:
Time series models have been applied in many areas including economics, stuck recruitment and the environment. Most environmental time series involve highly correlated dependent variables, which makes it difficult to apply conventional regression analysis, Traditionally, regression analysis has been applied to the environmental dependent stock and recruitment relationships for crustacean species in Western Australian fisheries. Alternative models, such as transfer function models and state space models have the potential to provide unproved forecasts for these types of data sets. This dissertation will explore the application of regression models, transfer function models, and state space models to modelling the puerulus stage of the western rock lobster (Panulirus Cynus) in the fisheries of Western Australia. The transfer function models are consulted to examining the influences of the environment on crustacean species and can be used where correlated variables are involved. These models aim at producing short-term forecasts that may help in the management of the fisheries. In comparison with regression models, TFM models gave better forecast values with state space models given the forecast values in the first two years. Overall, it was shown that environmental effects, westerly winds and the Leeuwin Current, have a significant effect on the puerulus settlement for Dongara and Alkimos. It was also shown that westerly winds and spawning stock have a significant effect on the puerulus settlement at the Abrolhos Islands.
28
Rigby, Elaine Rose. "Modelling results of student evaluations to improve the quality of teaching in accounting departments." Thesis, Canberra, ACT : The Australian National University, 1995. http://hdl.handle.net/1885/133664.
Повний текст джерелаАнотація:
The Course Evaluation Questionnaire is a student evaluation instrument designed to
measure the teaching performance of academic organisational units. The statistical
qualities of its scales, as well as their sensitivity, reliability and validity have been
confirmed in other studies. This study situates the development of the CEQ within the
context of public sector reform in Australia, which emphasised accountability measured
through performance indicators. It reviews previous research using the CEQ and
attempts to apply the CEQ in a new way, by using responses from students who were
enrolled in a first year accounting subject at three established universities, to construct a
model which quantifies the relationship between students' overall satisfaction score and
certain variables which were tested for their contribution to students' satisfaction. The
variables which were found to make a statistically significant contribution to student
satisfaction were: good teaching; clear goals and standards; appropriate workload;
emphasis on student independence; gender; language background; and university. The
major conclusions reached are 1) that of the five CEQ scales good teaching appears to be
most strongly related to overall satisfaction and that positive effect is the same at all three
universities, 2) that gender affects satisfaction at all three universities and 3) that
language background has an effect at two universities. The implications of these findings
for quality teaching in accounting courses and for accounting education research are
discussed.
29
Choi, Yoon-Hong. "The mathematical modelling of the Ross River Virus transmission." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1997. https://ro.ecu.edu.au/theses/896.
Повний текст джерелаАнотація:
Ross River virus is one of the most severe communicable diseases in Australia. During the 1995/96 outbreak of Ross River virus in south-western Australia, over 1 ,300 human cases were reported. Since the symptoms of the disease are sometimes too weak to be diagnosed, it is important to determine the number of humans who actually contracted the virus during outbreaks. To do this, several mathematical models with different hypotheses are constructed and analysed mathematically. The threshold mathematical conditions of these models suggest that as well as the size of the vector mosquito population, the population size and length of viraemia periods; of host populations and the infection rates between the hosts and vectors play the main roles in the transmission. Several parameters in the transmission are currently unknown, so only simple models of RRV transmission are computer-simulated. Some of the unknown parameters are extrapolated from published studies of other arboviruses. The sensitivities of the models to some of the unknown parameters are also examined. Simulation results indicate the sero-conversion rates and ratios of clinical to subclinical human infections during the outbreaks which occurred in the Peel and Leschenault districts in Southwestern Australia.
30
Bari, Mohammed A. "A distributed conceptual model for stream salinity generation processes : a systematic data-based approach." University of Western Australia. School of Earth and Geographical Sciences, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0058.
Повний текст джерелаАнотація:
[Truncated abstract] During the last fifty years mathematical models of catchment hydrology have been widely developed and used for hydrologic forecasting, design and water resources management. Most of these models need large numbers of parameters to represent the flow generation process. The model parameters are estimated through calibration techniques and often lead to ‘unrealistic’ values due to structural error in the model formulations. This thesis presents a new strategy for developing catchment hydrology models for representing streamflow and salinity generation processes. The strategy seeks to ‘learn from data’ in order to specify a conceptual framework that is appropriate for the particular space and time scale under consideration. Initially, the conceptual framework is developed by considering large space and time scales. The space and time scales are then progressively reduced and conceptual model complexity systematically increased until ultimately, an adequate simulation of daily streamflow and salinity is achieved. This strategy leads to identification of a few key physically meaningful parameters, most of which can be estimated a priori and with minimal or no calibration. Initially, the annual streamflow data from ten experimental catchments (control and cleared for agriculture) were analysed. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in stream zone saturated area. The annual evapotranspiration losses from native vegetation and pasture, the ‘excess’ water (resulting from reduced transpiration after land use change), runoff and deep storage were estimated by a simple water balance model. The model parameters are obtained a priori without calibration. The annual model was then elaborated by analysing the monthly rainfall-runoff, groundwater and soil moisture data from four experimental catchments. Ernies (control, fully forested) and Lemon (53% cleared) catchments are located in zone with a mean annual rainfall of 725 mm. Salmon (control, fully forested) and Wights (100% cleared) are located in zone with mean annual rainfall of 1125 mm. Groundwater levels rose and the stream zone saturated area increased significantly after clearing. From analysis of this data it was evident that at a monthly time step the conceptual model framework needed to include a systematic gain/loss to storage component in order to adequately describe the observed lags between peak monthly rainfall and runoff.
31
Nixon, John Bruce. "Dispersion modelling using finite-difference methods with application to larval western king prawn (Pencieus latisulcatus) in Spencer Gulf, South Australia /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phn736.pdf.
Повний текст джерела
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JACOMINO, VANUSA M. F. "Implementacao de uma metodologia para avaliacao das incertezas associadas as previsoes feitas por um modelo de transporte de sedimentos e poluentes em bacias hidrograficas." reponame:Repositório Institucional do IPEN, 1997. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10656.
Повний текст джерелаАнотація:
Made available in DSpace on 2014-10-09T12:42:47Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:56:19Z (GMT). No. of bitstreams: 1 05234.pdf: 8658831 bytes, checksum: 5fdbfa575f19ac2ea95052849f7b67f1 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
33
Reimnitz, Marc. "Shear-slip induced seismic activity in underground mines : a case study in Western Australia." University of Western Australia. School of Civil and Resource Engineering, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0062.
Повний текст джерелаАнотація:
Mining induced seismic activity and rockbursting are critical concerns for many underground operations. Seismic activity may arise from the crushing of highly stressed volumes of rock around mine openings or from shear motion on planes of weakness. Shear-slip on major planes of weakness such as faults, shear zones and weak contacts has long been recognized as a dominant mode of failure in underground mines. In certain circumstances, it can generate large seismic events and induce substantial damage to mine openings. The Big Bell Gold mine began experiencing major seismic activity and resultant damage in 1999. Several seismic events were recorded around the second graphitic shear between April 2000 and February 2002. It is likely that the seismic activity occurred as a result of the low strength of the shear structure combined with the high level of mining induced stresses. The stability of the second graphitic shear was examined in order to gain a better understanding of the causes and mechanisms of the seismic activity recorded in the vicinity of the shear structure as mining advanced. The data were derived from the observation of the structure exposures, numerical modelling and seismic monitoring. The numerical modelling predictions and the interpreted seismic monitoring data were subsequently compared in order to identify potential relationships between the two. This thesis proposes the Incremental Work Density (IWD) as a measure to evaluate the relative likelihood of shear-slip induced seismic activity upon major planes of weakness. IWD is readily evaluated using numerical modelling and is calculated as the product of the average driving shear stress and change in inelastic shear deformation during a given mining increment or step. IWD is expected to correlate with shear-slip induced seismic activity in both space and time. In this thesis, IWD was applied to the case study of the second graphitic shear at the Big Bell mine. Exposures of the second graphitic shear yielded information about the physical characteristics of the structure and location within the mine. Numerical modelling was used to examine the influence of mining induced stresses on the overall behaviour of the shear structure. A multi-step model of the mine was created using the three- dimensional boundary element code of Map3D. The shear structure was physically incorporated into the model in order to simulate inelastic shear deformation. An elasto-plastic Mohr-Coulomb material model was used to describe the structure behaviour. The structure plane was divided into several elements in order to allow for the comparison of the numerical modelling predictions and the interpreted seismic data. Stress components, deformation components and IWD values were calculated for each element of the shear structure and each mining step. The seismic activity recorded in the vicinity of the second graphitic shear was back analysed. The seismic data were also gridded and smoothed. Gridding and smoothing of individual seismic moment and seismic energy values resulted in the definition of indicators of seismic activity for each element and mining step. The numerical model predicted inelastic shear deformation upon the second graphitic shear as mining advanced. The distribution of modelled IWD suggested that shear deformation was most likely seismic upon a zone below the stopes and most likely aseismic upon the upper zone of the shear structure. The distribution of seismic activity recorded in the vicinity of the shear structure verified the above predictions. The seismic events predominantly clustered upon the zone below the stopes. The results indicated that the seismic activity recorded in the vicinity of the second graphitic shear was most likely related to both the change in inelastic shear deformation and the level of driving shear stress during mechanical shearing. Time distribution of the seismic events also indicated that shear deformation and accompanying seismic activity were strongly influenced by mining and were time-dependant. Seismic activity in the vicinity of the second graphitic shear occurred as a result of the overall inelastic shear deformation of the shear structure under mining induced stresses. A satisfactory relationship was found between the spatial distribution of modelled IWD upon the shear structure and the spatial distribution of interpreted seismic activity (measured as either smoothed seismic moment or smoothed seismic energy). Seismic activity predominantly clustered around a zone of higher IWD upon the second graphitic shear as mining advanced. However, no significant statistical relationship was found between the modelled IWD and the interpreted seismic activity. The lack of statistical relationship between the modelled and seismic data may be attributed to several factors including the limitations of the techniques employed (e.g. Map3D modelling, seismic monitoring) and the complexity of the process involved.
34
Yap, C. S. "Modelling and risk analysis of the western rock lobster (Panulirus cygnus) fishery of Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1995. https://ro.ecu.edu.au/theses/1462.
Повний текст джерелаАнотація:
The predictive power for short-term forecasting of selected biomass dynamic models was examined using the standardised catch and effort data from the 1944/45 to 1990/91 season of the western rock lobster. Risk analysis of the fishery based on the predicted fishing efforts with the Deriso-Schnute delay-difference model indicates a high probability of recruitment failure. Some hypothetical management strategies of reducing fishing effort were evaluated by taking into consideration the total catch and biological risk to the fishery.
35
Cordin, Robin M. "Psychopathic-like-traits and aggression in suspended mainstream school children and adolescents." University of Western Australia. Graduate School of Education, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0100.
Повний текст джерелаАнотація:
[Truncated abstract] The overall aim of the research reported in this thesis was to explore the viability and utility of the construct of psychopathy and aggression in children and adolescents. Specifically, by taking a developmentally informed approach it sought to develop new instrumentation which measured psychopathic-like-traits, and verbal proactive and reactive aggression in non-referred mainstream school children and adolescents. To achieve this, four separate yet interrelated studies were conducted. Study One comprised three phases relating to the development and validation of two new instruments. In Phase One the instruments currently used to measure psychopathy were reviewed and items relevant to young persons were selected for inclusion in a draft version of the new psychopathy screening instrument. Phase Two, which sought to further explore the construct of psychopathy in children and adolescents, comprised a series of interviews with school principals, deputy principals, psychologists, and education officers at the main juvenile detention centre in Perth, Western Australia. These interviews provided information relating to the behaviour and characteristics of children and adolescents who present with psychopathic-like-traits. As a consequence of the feedback from the Phase Two data, Phase Three reviewed the instrumentation currently used to measure aggression in children and adolescents. From this items were selected for possible inclusion in an aggression questionnaire. The data gathered over these three phases resulted in 117 psychopathy related items being generated for the new instrument, which were subsequently reduced to 56 when duplicated items were identified and the extant knowledge of the construct applied. The 56 items were retained in a draft version of the newly developed instrument, which was named the Child and Adolescent Psychopathy Screening Instrument (CAPSI). The Study One data revealed the instrumentation used to date provided few measures of physical and verbal aggression - a characteristic of psychopathic-like behaviour. Thus, a review of instrumentation together with the information from the interviews resulted in 63 aggression items being generated. ... Study Four utilised information from the CAPSI and the CASA in conjunction with in-depth interviews to generate case studies to further elucidate the characteristics of children and adolescents with psychopathic-like-traits and extreme aggression. Case studies were undertaken with seven male students ranging in age from 8 to 15 years who had been suspended from mainstream schools. All boys scored very highly on the new instruments. All presented with extreme aggression, with some exhibiting proactive or premeditated aggression combined with a superficially engaging personality, insincere charm, lack of remorse, and lack of empathy. The findings from all four research studies are discussed in the light of the literature reviewed and the aims of the research. Implications are then drawn for researchers and clinicians, and directions for further research are suggested.
36
Ugbo, Justin Petroleum Engineering Faculty of Engineering UNSW. "A new model for evaluating water saturation in shaly sand reservoirs using quantitative x-ray diffraction and cation exchange capacity cliff head field, Western Australia." Awarded by:University of New South Wales. Petroleum Engineering, 2007. http://handle.unsw.edu.au/1959.4/40443.
Повний текст джерелаАнотація:
Interpretation problems are commonly associated with calculating water saturation in nonhomogenous shaly sand reservoirs. Redefining petrophysical properties based on well logs in shaly sand reservoirs by using fundamental geologic attributes is an important tool in developing subsurface hydrocarbon resources. Studies of the electrical anisotropy of shaly sands have shown that the level of our understanding and our ability to correctly evaluate low resistivity and low contrast pay can be greatly improved. The model developed in this thesis is similar in form to the shaly sand Dual Water model by Clavier et al. (1984). It is an experiment based model designed to directly assess and quantify the mineralogical and electrical effects of clay minerals in heterogeneous reservoirs. Clay minerals usually have multiple effects on petrophysical properties obtained from geophysical well log measurements. The total expansible clay model evaluates these effects via direct measurement of independent mineralogy and conductivity of clay minerals within reservoir sands. This model integrates the following as an effective basis for characterizing shaly sand reservoirs: ??? Rietveld based Siroquant assay for quantitative X-ray diffraction, used in determining mineral percentages from standard XRD trace patterns, ??? Cation exchange capacity, used to determine the quantity of cations involved in the exchange at the shale-water interface, ??? Porosity, permeability, density and resistivity measurements, ??? Thin section petrography, used in identifying mineral patterns, visible porosity and reservoir quality. Overall, application of correlations drawn from the model yields improved results for water saturation which appeared consistent with those earlier calculated using known water saturation models (Clavier et al Dual Water model, 1984, Juhasz, 1981). A total of twenty three samples from two wells in the Cliff Head fIeld were analyzed for this study.
37
Klopp, Gregory Mark. "Seismic design of unreinforced masonry structures /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phk658.pdf.
Повний текст джерела
38
Yang, Wenling. "M-GARCH Hedge Ratios And Hedging Effectiveness In Australian Futures Markets." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2000. https://ro.ecu.edu.au/theses/1530.
Повний текст джерелаАнотація:
This study deals with the estimation of the optimal hedge ratios using various econometric models. Most of the recent papers have demonstrated that the conventional ordinary least squares (OLS) method of estimating constant hedge ratios is inappropriate, other more complicated models however seem to produce no more efficient hedge ratios. Using daily AOIs and SPI futures on the Australian market, optimal hedge ratios are calculated from four different models: the OLS regression model, the bivariate vector autoaggressive model (BVAR), the error-correction model (ECM) and the multivariate diagonal Vcc GARCH Model. The performance of each hedge ratio is then compared. The hedging effectiveness is measured in terms of ex-post and ex-ante risk-return traHe-off at various forcasting horizons. It is generally found that the GARCH time varying hedge ratios provide the greatest portfolio risk reduction, particularly for longer hedging horizons, but hey so not generate the highest portfolio return.
39
Watson, Eric Craig. "Use of Distance Weighted Metrics to Investigate Landscape-Stream Temperature Relationships Across Different Temporal Scales." PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3117.
Повний текст джерелаАнотація:
Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these landscape variables and stream conditions. Weighting the relevant landscape variables based on hydrologically defined distances offers a potential method of increasing the predictive capacity of statistical models. Using observations from three grouped watersheds in the Portland Metro Area (n=66), I have explored the use of three different weighting schemes against the standard method of taking an areal average. These four different model groups were applied to four stream temperature metrics: mean seven-day moving average maximum daily temperature (Mean7dTmax), number of days exceeding 17.8 °C (Tmax7d>17.8), mean daily range in stream temperature (Range_DTR), and the coefficient of variation in maximum daily temperature (CV_Tmax). These metrics were quantified for the 2011 dry season. The strength of these model groups were also examined at a monthly basis for each of the four months within the dry season. The results demonstrate mixed effectiveness of the weighting schemes, dependent on both the stream temperature metric being predicted as well as the time scale under investigation. Models for Mean7dTmax showed no benefit from the inclusion of distance weighted metrics, while models for Range_DTR consistently improved using distance weighted explanatory variables. Trends in the models for 7dTmax>17.8 and CV_Tmax varied based on temporal scale. Additionally, all model groups demonstrated greater explanatory power in early summer months than in late summer months.
40
Wilmot, Peter Nicholas. "Modelling cooling tower risk for Legionnaires' Disease using Bayesian Networks and Geographic Information Systems." Title page, contents and conclusion only, 1999. http://web4.library.adelaide.edu.au/theses/09SIS.M/09sismw744.pdf.
Повний текст джерелаАнотація:
Includes bibliographical references (leaves 115-120) Establishes a Bayesian Belief Network (BBN) to model uncertainty of aerosols released from cooling towers and Geographic Information Systems (GIS) to create a wind dispersal model and identify potential cooling towers as the source of infection. Demonstrates the use of GIS and BBN in environmental epidemiology and the power of spatial information in the area of health.
41
Fu, Baihua. "An integrated catchment-scale approach to indentifying suspended sediment sources." Phd thesis, 2008. http://hdl.handle.net/1885/150837.
Повний текст джерела
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Gilmour, Juliet Karla. "An integrated modelling approach for assessing land use change and water allocation policy options." Phd thesis, 2003. http://hdl.handle.net/1885/148557.
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Britch, Michael J. "Watershed modeling at Yucca Mountain, Nevada." Thesis, 1990. http://hdl.handle.net/1957/38116.
Повний текст джерелаАнотація:
Studies are currently underway to determine the suitability of Yucca Mountain
in Nevada as the nation's first high-level nuclear waste repository. Values of net
infiltration are required to determine pre-waste emplacement groundwater travel times
and the performance of the repository as a waste containment system. The objective of
this study was to develop a numerical model to perform water balance calculations and
predict rates of net infiltration for the site. The model included processes of
precipitation, runoff, evapotranspiration, infiltration, and redistribution of water within
a soil profile. The watershed was divided into 477 grid cells 75.7 x 75.7 m. The
elevation, slope, aspect, and hydrologic properties were assumed to be constant within
a grid cell but varied from one cell to the next Water balance calculations were
performed for each cell using a one-dimensional form of Richards equation. The
solution was obtained using the finite difference method with Newton-Raphson
iteration.
The model was calibrated using water content data obtained from neutron-moisture
meter measurements in boreholes located in Pagany Wash Watershed
Measurements were made in channel and terrace alluvium and in tuffs. Computer
simulations reproduced water content data for a major precipitation event that occurred
in 1984. Simulations verified the importance of antecedent soil water content in
controlling the occurrence of runoff. Sensitivity analysis indicated that the soil and
alluvium grain-size distributions, which are used to calculate unsaturated hydraulic
conductivity, can greatly affect predicted rates of water movementGraduation date: 1991
44
Post, David Andrew. "Identification of relationships between catchment-scale hydrologic response and landscape attributes." Phd thesis, 1996. http://hdl.handle.net/1885/144311.
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Gallant, John Christian. "Pesticide transport models for assessing nonpoint source pollution in Australia." Master's thesis, 1992. http://hdl.handle.net/1885/144088.
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46
Vache, Kellie B. "Model assessment of the effects of land use change on hydrologic response." Thesis, 2003. http://hdl.handle.net/1957/31606.
Повний текст джерелаАнотація:
The effect of landuse change on the hydrologic, biogeochemical and
ecological response of watersheds is a concern throughout the world. To help
characterize the potential magnitude of such changes, and of the potential to
remediate or avoid undesirable features, studies focused on the cumulative
watershed effects of site level change are necessary. The current state of the art
model for water quality in agricultural lands, Soil Water Assessment Tool
(SWAT), was used to estimate the effects of a set of future landscape scenarios on
water quality in the Corn Belt region of the United States. These results indicated
that changes to the current water quality management strategies will be necessary
to significantly improve water quality in the Corn Belt region. In addition, the
experience of implementing SWAT suggested a variety of changes to the model
structure and study design with potential to improve the quality of the results.
These changes include improved treatment of hydrologic process, full integration
of input data and model code, different methods of distributing data across space,
the use of fewer parameters, more sophisticated numerical techniques, and
improved methods for generating potential landscape scenarios.
A new model structure (WET_Hydro) was developed to address these
issues. The hydrologic components of the model focus on a conceptual physically
based characterization of the movement of water in soils, as overland flow, and in
channels. Tests using a variety of input data sets, including both synthetic inflows
and real watershed data were developed to verify the hydrologic components of
the model. Additional model analyses evaluate how model scale interacts with
parameters and with measurements. These analyses point toward additional
criteria that may prove useful to the determination of correct model scales and to
the utility of the flexible model structure which provides automatic changes to
model scale. In addition to the scale analysis, a method of estimating the average
new water contribution to storm discharge was developed.. This additional model
criterion was shown to provide further understanding of model utility under
different hydrologic regimes.
The hydrologic model was extended to produce estimates of erosion and
sediment export. Sensitivity to various restoration options were developed
focusing on simple descriptions of remediation potential, and a minimum of
parameters. In addition, the water quality model was coupled with a Decision
Support System (DSS). Example applications demonstrate the potential of the
combination to improve the process of restoration planning at the watershed scale.Graduation date: 2003
Best scan available. Figures in original are very light.
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Rasser, Paul Edward. "Calibration of numerical models with application to groundwater flow in the Willunga Basin, South Australia." 2001. http://thesis.library.adelaide.edu.au/public/adt-SUA20030414.111541/index.html.
Повний текст джерелаАнотація:
Bibliography: 80-82. Electronic publication; full text available in PDF format; abstract in HTML format. The process of calibrating a numerical model is examined in this thesis with an application to the flow of groundwater in the Willunga Basin in South Australia. The calibration process involves estimating unknown parameters of the numerical model so that the output obtained from the model is comparable with data that is observed in the field. Three methods for calibrating numerical models are discussed, these being the steepest descent method, the nonlinear least squares method, and a new method called the response function method. Electronic reproduction.[Australia] :Australian Digital Theses Program,2001.
48
Wildegger-Gaissmaier, Anna Elisabeth. "Fluidized bed utilization of South Australian coals / Anna Elisabeth Wildegger-Gaissmaier." Thesis, 1988. http://hdl.handle.net/2440/18806.
Повний текст джерела
49
Jaforullah, Mohammad. "Energy modelling in a general equilibrium framework with alternative production specifications / Mohammad Jaforullah." Thesis, 1988. http://hdl.handle.net/2440/18835.
Повний текст джерела
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Giesecke, James. "FEDERAL-F : a multi-regional multi-sectoral dynamic model of the Australian economy / by James A.D. Giesecke." 2000. http://hdl.handle.net/2440/19810.
Повний текст джерелаАнотація:
Bibliography: p. 648-661.2 v. (xviii, 661 p. : ill.([1] col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, School of Economics, 2001