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2021 — A Two-Parameter Lindley-Binomial Distribution: Properties and ApplicationsAbstract
The binomial distribution is a common and well known distribution that many situations and applications of binomial distribution can be found. In the real life anything that can be thought of a success or a failure can be considered as a Binomial distribution. However, this kind of instances does not fit to binomial distribution well at all the time. Therefore, in order to improve the ability of fitting various models, two-parameter Lindley distri- bution is used to combine with binomial distribution. In this thesis, a new generalized discrete distribution, that is named as two-parameter Lindley-binomial distribution, is introduced by compounding … Read more
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2022 — Multi-level energy-environmental-economic modeling for supporting low-carbon transition of power systems under uncertaintyAbstract
To combat climate change, the low-carbon transition of electricity systems is of critical significance. Such transition is a complex and long-term process, involving many social, economic, environmental, technical and political factors, and requires a complete analysis for every aspect of the transition pathways. In this dissertation, low-carbon transition strategies of electricity systems were studied from three levels. A set of identification, optimization, and simulation models were developed to facilitate the analysis. For the efforts made at the technical level, the necessity and feasibility of introducing an emerging low-carbon power generating technology (i.e., SMRs) have been studied, with a focus on … Read more
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2019 — Engagement Paper for the Animated Film MASKAbstract
Mask is a stop motion animation film that aims to discuss the impact of emigration on the newcomer as a subject within established societies. The story takes place within an imagined setting, in which a mask is the only official signifier of one’s identity. However, the story still reflects my personal experience in terms of language proficiency and a newcomer’s adjustments to living in Canada. Because of the film’s allegorical characteristics, one of my expectations was to have a diversity of interpretations of the film depending on the viewers’ personal background and experience, rather than the meaning being derived just … Read more
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2018 — Game Theoretic Approaches to Three-Way DecisionsAbstract
Uncertainty and imprecision are intrinsic features of available data about the real world. An object is uncertain if we cannot make sure decisions about if the object belongs to a target concept. Three-way decisions provide three options, i.e., accept, reject, and non-commitment, in the face of uncertainty. All objects are divided into three regions according to which option is selected for each object. The determination of three-way decisions is a key issue of analyzing uncertain data. When multiple evaluation measures are involved, determining three-way decisions from a tradeoff perspective is a challenging process. The thesis focuses on determining three-way decisions … Read more
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2012 — Motion and Mobilization of Oil Slugs in a Capillary Model Under Stationary ConditionsAbstract
In this research, both experimental and numerical investigations are conducted to study the mechanism behind slug flow in a capillary tube. A 1.2 mm inner diameter capillary model is employed to represent the pore structure of porous media. A single oil slug is trapped in the tube and mobilized from a stationary condition by water injection. During the flow process, the flow behavior, the maximum driven pressure to mobilize the oil slug and the flow time to reach the maximum pressure are recorded and analyzed. The results show that the generation of a thin water film between the oil slug … Read more
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2017 — Experimental Research on Multiphase Liquid Mobilization and Motion in Capillary and Micro Models Subjected to External Low Frequency Vibratory ExcitationsAbstract
The research of this dissertation experimentally investigates the impacts of external vibratory excitation on the mobilization and motion of multiphase liquid in capillary and microcell models, aiming for understanding the mechanism of oil-water mobilization and flow in pore structures subjected to external excitations. Experiments with capillary models are first conducted; in which both straight capillary and curved capillary models are employed as an analogue of the pore structures. The mobilization and motion of an oil slug trapped in the capillary models with capillary forces are studied in the research. The models considered are subjected to both external pressures created by … Read more
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2019 — Decomposition of Certain Representations Into A Direct Sum of Indecomposable RepresentationsAbstract
Representations of quivers and posets are produced by persistent homology. It is possible to decompose such representations into direct sums of indecomposable representations. The indecomposable representations of quivers and posets that arise from one dimensional persistent homology are well understood. However, the same is not true for multidimensional persistent homology. This thesis finds such a list of indecomposable representations for a very simple case of a poset that can arise from multidimensional persistent homology, and proves that it is possible to decompose a representation of such a poset into a direct sum of these indecomposables. Read more
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2014 — Estimation of Relative Permeability and Capillary Pressure for Hydrocarbon Reservoirs Using Ensemble-Based History Matching TechniquesAbstract
Reservoir simulation is generally used in modern reservoir management to make sound reservoir development strategies, requiring a reliable and up-to-dated reservoir model to predict future reservoir performance in an accurate and efficient way. It is the history matching that is able to provide a reliable reservoir model by using the observed data to calibrate the reservoir model parameters. In this study, assisted history matching techniques have been developed to inversely and accurately evaluate relative permeability and capillary pressure for the hydrocarbon reservoirs. An assisted history matching technique based on the confirming Ensemble Kaman Filter (EnKF) algorithm has been developed, validated, … Read more
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2016 — Study of Phase Behaviours of Reservoir Fluids with Consideration of Adsorption and Capillary PressureAbstract
With the development of petroleum science and technology, a systematic understanding of the fundamental phase behaviours of petroleum fluids in bulk volume has been well established. However, the effect of porous media on the phase behaviours of reservoir fluids has always been considered a deep and complicated research topic that has attracted the attention of many scholars worldwide. During the production process, with the change of pressure and temperature, the phase behaviours of reservoir fluids are then changed. Strictly speaking, the process of phase equilibrium occurs in the porous media of formation, and the effect of porous media cannot be … Read more
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2021 — Study on the Binary Interactions of Gas, Brine and Reservoirs Porous MediaAbstract
As several operations in the reservoir engineering may involve gas injection or production, such as gas reservoir development, enhanced oil/gas recovery (EOR/EGR), CO2 capture and sequestration, and underground gas storage, etc., the study on the interactions of gas, brine and porous medium is important. Three typical binary interactions are discussed in this study including the mutual dissolution of gas and brine, the adsorption of pure gases and gas mixtures in the reservoir porous media, and the salt precipitation induced by brine in the reservoir porous media. For the mutual dissolution of gas and brine, this work improves a new theoretical … Read more
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2024 — Performance evaluation of a multifractured horizonal well in an unconventional reservoir with fracture networks and flow dynamicsAbstract
With the advancement of horizontal drilling and hydraulic fracturing technologies, the unconventional reservoir resources (e.g., tight oil and shale gas) have received a growing attention; however, it is a challenging task to accurately simulate the transient pressure response and single/two-phase flow behaviour due to the reservoir boundary, fracture geometry, fracture network, and flow dynamics including stress-sensitivity, slippage effect, non-Darcy flow, and gas adsorption/desorption. Therefore, it is of a fundamental and practical importance to evaluate the performance of a multifractured horizontal well (MFHW) in an unconventional reservoir conditioned to an arbitrary boundary, fracture geometry, and complex fracture networks with the consideration … Read more
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2023 — Characterization of Cenomanian-early Turonian bentonites in southwestern Saskatchewan through lithostratigraphy and chemostratigraphy analysisAbstract
Volcanic eruptions can disperse tephra over a wide area, and may result in deposition of ash far from their sources. For example, ash from the 1980 eruption of Mt. St. Helens volcano in Washington State was observed falling upon Regina, Saskatchewan. Bentonite is a name for widely distributed beds of altered ash that have the potential to be used as isochronous horizons in lithostratigraphic correlation, much in the same way that tephrochronology is applied to young volcanic deposits. Numerous bentonite horizons are preserved within Late Cretaceous strata of western Canada and northern USA, and several widespread layers delineate unit or … Read more
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2021 — Experimental and Modelign of Foam Physics in Porous MediaAbstract
Foam is a dispersion of gas in a liquid, where the liquid is continuous and part of the gas is made discontinuous by thin liquid films (lamellae) (Hirasaki and Lawson, 1985). Foam promises to substantially improve reservoir sweep in gas-injection enhanced oil recovery (EOR) projects. Predictive modeling efforts are hindered by many complex rheological characteristics shared by foams, including a yield stress, non-Newtonian viscosity, finite shear modulus and slip at the wall, etc. (Reinelt and Kraynik, 1989). This dissertation focuses on experimental and numerical simulations on foam physics across multiple scales. The first objective is to develop ultimately a mechanistic, … Read more
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2017 — Comprehensive Experimental Study on Foam Flooding for Enhancing Heavy Oil RecoveryAbstract
At present, thermal method, such as steam injection and in-situ combustion are the best for recovering heavy oil. However, some reservoirs in Canada and the United States with ultra thin oil formations saturated with lower viscous heavy oil (50~200 cp), chemical flooding is more attractive compared with conventional thermal methods. This study is aimed to explore the effectiveness and potential application of foam flooding for enhancing moderately viscous oil recovery. The effects of surfactant type and concentration on surfactant properties were examined in terms of bulk foam ability and foam stability by the Ross-miles method and Warning blender method. Foam … Read more
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2015 — Model Checking for Longitudinal Data: Root Mass StudyAbstract
A three-year completely randomized design experiment was implemented in Alberta, Manitoba, and Saskatchewan in 2007. It was conducted by the Department of Biology, University of Regina, to measure root mass expressed per soil volume (g root /m3). Root mass data depends on four main factors: temperature, precipitation, clipping, and depth. Temperature and precipitation show climate impact. Clipping indicates Human activities impact. Depth factor could be considered to be time level (t) so that we can consider root mass data as longitudinal data. My research interests are to find a reasonable model and some significant interaction terms among the main factors. … Read more
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2023 — A theory of spatial granular computingAbstract
This thesis proposes a theory of spatial granular computing. A granule is composed of one or more atomic granules, and the rationality of this definition is expounded from four aspects: simplicity, applicability, measurability, and visualization. A projection is introduced, which is a one-to-one mapping from granules to points in an nD unit hypercube. Based on this, some basic questions of spatial granular computing are discussed. When discussing the rough set models from the perspective of micro knowledge space, all the models can be easily applied to incomplete information systems and continuous information systems as well. For any equivalence granule in … Read more
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2022 — Integrated optimization and performance evaluation of hybrid steam-solvent processes in a post-CHOPS reservoir with consideration of wormhole networksAbstract
As for the enormous heavy oil resources deposited in Western Canada (i.e., Alberta and Saskatchewan), cold heavy oil production with sand (CHOPS) has been the most common primary production technique to produce heavy oil, water, gas, and sand altogether by using progressive cavity pumps (PCPs). In general, typical recovery factors are low about 5-15% of original-oil-in-place (OOIP) due mainly to the in-situ generation of open channels (i.e., wormholes) and foamy oil in the unconsolidated formations, and thus efficient enhanced oil recovery (EOR) techniques are required for the post-CHOPS reservoirs. In this study, techniques have been developed to evaluate performance of … Read more
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2024 — Joint survival and longitudinal modelling for combined cohortsAbstract
A primary goal of survival analysis is modelling the time from an initial event to a failure event and the factors which affect the hazard rate. In this thesis, we consider data drawn from an incident cohort study with follow-up and a prevalent cohort study with follow-up, yielding right-censored failure time data and left-truncated right-censored failure time data, respectively. In addition to the failure/censoring times, we assume the survival data include other measured covariates, for example, longitudinal measurements collected throughout the failure/censoring time durations. In this thesis, we review the methods of estimation for the proportional hazards model, the linear … Read more
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2015 — Enhanced Physicochemical Processes for the Treatment of petroleum-Contaminated SystemsAbstract
In Canada, environmental issues caused by petroleum-contaminated sites are becoming a major concern. Therefore, effective physicochemical remediation technologies are desired for produced water treatment and groundwater remediation in oil fields. In this dissertation research, the feasibility of treating produced water using synthetic polymers combined with natural diatomite was evaluated. Using diatomite as an adsorbent and a coagulant aid, this study provided an economical and enhanced approach for utilizing diatomite in the clean-up of produced water. A pilot-scale electrocoagulation process was developed for enhanced removal of hardness, chemical oxygen demand, and turbidity to mitigate the scaling and fouling of Reverse Osmosis … Read more
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2016 — Explorations in Periodicity: New Techniques in Audio and Kinematic DataAbstract
Understanding the inherent periodic nature of many signals can help us analyze and obtain more useful information about these signals. In this thesis, a periodicityoriented thinking and analysis approach is presented with signals from three di erent elds. In the rst study, a Waveform-aligned Adaptive Window (WAAW) technique is considered based on the periodic nature of monophonic audio signals. The periodicity information is extracted before the traditional spectral analysis which uses the short-time Fourier transform (STFT). Instead of xed-sized frames, a dynamic size is determined for each frame based on its cycle length. The direct bene t is that it … Read more
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2022 — Quantification of nonequilibrium phase behaviour of alkane solvents/CO2/alkaline water-heavy oil systems under reservoir conditionsAbstract
During the primary stage, the in-situ generated foamy oil has been found to be responsible for an unexpected high recovery factor, a remarkably low gas-oil ratio (GOR), and a higher-than-expected well production rate. Such a phenomenon can also be artificially induced by injecting alkane solvents (e.g., methane and propane) or CO2 to a heavy oil reservoir; however, the gas exsolution of foamy oil is not yet well understood due mainly to the complicated physical processes. On the other hand, the associated emulsifications resulted from the in-situ generated surfactant(s) during alkaline flooding in a heavy oil reservoir lead to an increase … Read more
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2012 — Utilization of co2 for pressure maintenance and improving oil recovery in heavy oil reservoirs.Abstract
Tremendous resources of heavy oil are located in Western Canada, i.e., Alberta and Saskatchewan, most of which are contained in thin payzones. Thermal-based techniques have conventionally been utilized to enhance heavy oil recovery. However, characteristics of these thin reservoirs result in excessive heat losses to adjacent formations, leading to thermal-based techniques ineffective and uneconomical in such heavy oil formation. Although pressure maintenance via gas injection has been applied in light and medium oil reservoirs, few attempts have been made to evaluate performance of CO2 injection for such purpose in a heavy oil reservoir. It is of practical and fundamental importance … Read more
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2016 — Enhanced Heat and Mass Transfer for Alkane Solvent(s)-CO2-Heavy Oil Systems at High Pressures and Elevated TemperaturesAbstract
The tremendous heavy oil reserves have recently attracted considerable attention for sustaining the increasing global oil consumption. Heavy oil reservoirs are characterized by high oil viscosity and drastic drop of reservoir pressure in a short period during production, imposing great challenges to recover such heavy oil resources. In practice, conventional steam-based thermal recovery techniques are generally ineffective or uneconomical in thin heavy oil reservoirs due to operational and environmental constraints. Since CO2 is a highly soluble, low cost, and environment-friendly injectant, hot CO2 injection is alternatively considered to be a promising technique for enhancing heavy oil recovery from these thin … Read more
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2012 — A Cost-Sensitive Approach to Ternary ClassificationAbstract
Bayesian inference and rough set theory provide two approaches to data analysis. There are close connections between the two theories as they both use probabilities to express uncertainties and knowledge about data. Several proposals have been made to apply Bayesian approaches to rough sets. This thesis draws results from two probabilistic rough set models, namely, decision-theoretic rough set models (DTRSM) and confirmation-theoretic rough set models (CTRSM) to propose a new Bayesian rough set model (BRSM) for cost-sensitive ternary classification. I argue that although the two classes of models share many similarities in terms of making use of Bayes’ theorem and … Read more