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Title: Community multiscale air quality (CMAQ) modeling of the atmospheric quality and pollutant deposition over the Terrace-Kitimat Valley of northwestern British Columbia, Canada
Contributors: Chibuike Onwukwe (author), Peter Jackson (thesis advisor), Waqar Haque (chair), Mark Grouix (committee member), Stephen Dery (committee member), Bruce Ainslie (committee member), Douw Steyn (committee member), University of Northern British Columbia Natural Resources & Environmental Studies (Degree granting institution)
Abstract: Tracking the effects of air pollution from industries is important for developing management strategies under changing emissions. However, computational tools for air pollution assessment often do not elucidate modeling uncertainty, making it difficult for environmental policy-makers to know how much confidence to put in model results, which also hampers aspects that may need improving. This study examined how the WRF-SMOKE-CMAQ modeling system with various planetary boundary-layer (PBL) schemes and atmospheric datasets mimics the local meteorology, air quality and acidic deposition at 1 km horizontal resolution over the industrializing Terrace-Kitimat Valley of northwestern British Columbia. Quantitative and qualitative correspondence of model outputs with observational data varied with station location, the nature of pollutant emissions, and quantity of chemical species. Valid model outputs were used to delineate present compliance with objectives on ambient fine particulate matter, and baseline exceedance of critical loads of sulfur and nitrogen deposition for the forest ecosystem. Spatial impacts of anticipated industrial emissions on the environment were also assessed. An additional 15 tonnes day-1 permissible SO2 emission from an aluminum smelter in Kitimat was projected to result in 50–88 % increase in aerial exceedance of the limit for protection of lichen, and 37–67 % increase in spatial exceedance of acidic deposition to soils. Cumulatively, 16–18 km2 of plant habitat, and 10–11 km2 of soil in an area contiguous with the smelter site will likely be damaged by its SO2 emission under the latest regulation. Should two Liquefied Natural Gas projects commence operations, cumulative NOx concentrations are expected to remain below harmful levels, while pre-existing areal exceedance of nitrogen deposition will barely increase (0–1 km2). An additional 4 km2 area will be exposed to SO2 concentrationsiii that are directly harmful to vegetation, while 13–14 km2 total area with an average of 29.7–35.0 kg ha-1 yr-1 excess sulfur deposition was estimated. These projections assumed all future emissions of NOx, SO2 and other air pollutants will be from elevated point sources.
Discipline: Natural Resources & Environmental Studies
Content Model: info:fedora/ir:thesisCModel
Date added: 2020

Title: An approach to remotely monitor glacier mass balance at seasonal to annual time scales, Columbia and Rocky Mountains, Canada
Contributors: Ben Mauri Pelto (author), Menounos Brian (thesis advisor), Matt Reid (chair), Shawn Marshall (committee member), Peter Jackson (committee member), Stephen Dèry (committee member), Roger Wheate (committee member), Gwenn Flowers (committee member), University of Northern British Columbia Natural Resources & Environmental Studies (Degree granting institution)
Abstract: My dissertation investigates glacier mass change in the Columbia and Rocky Mountains of British Columbia. In chapter one I discuss the importance of the cryosphere and glaciers, introduce the climate and glaciers of the study region, and outline the objectives and structure of this dissertation. Previous work established the feasibility of geodetic methods to accurately produce winter glacier mass balance and annual glacier mass balance. These studies demonstrate that geodetic surveys can be used to estimate mass balance during the accumulation season or for one glacier over a number of years. In chapter two, I refine these published methods to measure seasonal and annual mass balance for six glaciers within two mountain ranges from 2014–2018. I use synchronous field-based glaciological measurements, airbornelaser scanningsurveys (ALS) and satelliteimagery to quantify seasonal glacier mass change from 2014–2018. Chapter three reports on radar surveys I completed of the study glaciers, adding important observations to the global database of ice thickness. I use these observations and an existing flowline model, driven with observations of surface mass balance and glacier elevation to bias-correct ice thickness estimates for each glacier. Finally, I use the model to estimate ice thickness for all glaciers in the Columbia Basin and estimate total ice volume. Chapter four builds upon previous work which used surface topography, glacier mass balance, ice thickness, and ice velocity data to estimate ice flux at discrete glacier cross-sections. Previous efforts to infer the spatial distribution of mass balance have focused on glacier tongues. I expand upon this method, calculating surface mass balance between flux gates over the entire elevation range of three glaciers, over three years. I derive the altitude-mass balance relation and demonstrate that the relation can be accurately described with high-resolution elevation and ice flux data, and suggest that this method can be expanded for large-scale estimates. Chapter five summarizes the study’s major findings, highlights its limitations and discussed its broader implications. Finally, I make recommendations that will address knowledge gaps, and improve our understanding of changing glacier conditions and ability to model glacier dynamics.
Discipline: Natural Resources & Environmental Studies
Content Model: info:fedora/ir:thesisCModel
Date added: 2020

Title: Impact of westerly wind burst on El Niño-sourthern oscillation
Contributors: Mohammad Tabrez Alam (author), Youmin Tang (thesis advisor), Chengbo Fu (chair), Peter Jackson (committee member), Jianbing Li (committee member), Ruping Mo (committee member), Liang Chen (committee member), University of Northern British Columbia Natural Resources & Environmental Studies (Degree granting institution)
Abstract: Westerly wind bursts (WWBs), usually occurring in the tropical Pacific region, play a vital role in El Niño–Southern Oscillation (ENSO). In this study, we use a hybrid coupled model (HCM) for the tropical Pacific Ocean-atmosphere system to investigate WWBs impact on ENSO. To achieve this goal, two experiments are performed: (a) first, the standard version of the HCM is integrated for years without prescribed WWBs events; and (b) second, the WWBs are added into the HCM (HCM-WWBs). Results show that HCM-WWBs can generate not only more realistic climatology of sea surface temperature (SST) in both spatial structure and temporal amplitudes, but also better ENSO features, than the HCM. In particular, the HCM-WWBs can capture the central Pacific (CP) ENSO events, which is absent in original HCM. Furthermore, the possible physical mechanisms responsible for these improvements by WWBs are discussed.
Discipline: Natural Resources & Environmental Studies
Content Model: info:fedora/ir:thesisCModel
Date added: 2020

Title: Improving Sonar Sensor Fidelity in a Robot Simulator.
Contributors: Allan Edward Kranz (author), Charles Brown (Thesis advisor), Liang Chen (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: It is slow and expensive to develop robot control systems using real robots. Simulation can provide the benefits of lowering the time and cost. In order to take advantage of the benefits of development in a simulator we need high fidelity representations of actual sensors. Sensors do not provide perfect data and simulations that use either perfect models or models that are too simple will not translate well into the real world. This research introduces a sensor model that overcomes some of the existing limitations in current simulations and provides a methodology for developing both new models and corresponding testing regimes. An actual sensor is used in realistic situations to create authentic models that more closely match the performance of the robot in the real world. A simple sonar sensor is tested against three generic obstacles and a realistic software simulation model of its capabilities is created. The Simbad robot simulator is modified to use this model, a testing regime is created to validate the results, and improved performance over the existing model is achieved. --Leaf iii.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2015

Title: A flexible simulaton framework for the study of deadlock resolution algorithms in multicore systems
Contributors: Dhruv Desai (author), Alex Aravind (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Deadlock is a common phenomenon in software applications, yet it is ignored by most operating systems. Although the occurrence of a deadlocks in systems is not frequent, in some cases, the effects are drastic when deadlock occurs. The ongoing trend in processor technology indicates that future systems will have hundreds and thousands of cores. Due to this imminent trend in hardware development, the problem of deadlock has gained renewed attention in research. Deadlock handling techniques that are developed for earlier processors and distributed systems might not work well with multicore systems, due to their architectural differences. Hence, to maximize the utility of multicore systems, new programs have to be carefully designed and tested before they can be adopted for practical use. Many approaches have been developed to handle deadlock in multicore systems, but very little attention has been paid to comparing the performance of those approaches with respect to different performance parameters. To fulfil the above mentioned shortfalls, we need a flexible simulation testbed to study deadlock handling algorithms and to observe their performance differences in multicore systems. The development of such a framework is the main goal of this thesis. In the framework, we implemented a general a scenario, scenario for the Dining Philosopher's problem and scenario for the Banker's algorithm. In addition to these scenarios, we demonstrate the flexibility, soundness, and use of the proposed framework by simulating two different deadlock handling strategies "" deadlock avoidance (the Banker's algorithm) and deadlock detection (Dreadlocks). The deadlock detection is followed by deadlock recovery to resolve the detected deadlock. We also present result analysis for the different set of experiments performed on the implemented strategies. The proposed simulation testbed to study deadlocks in multicore systems is developed using Java. --Leaf i.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2016

Title: Modelling the distribution of advance regeneration in lodgepole pine stands in the Central Interior of British Columbia.
Contributors: Darin Warren Brooks (author), Phil Burton (Thesis advisor), Roger Wheate (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The recent mountain-pine beetle outbreak in the Central Interior of British Columbia is leaving unsalvaged stands with minimal silvicultural treatment, raising questions about their ability to regenerate and the implications of this uncertainty to future timber supply and habitat values. No system currently exists to predict, on a landscape level, which pine stands will have adequate stocking of advance regeneration suitable for release upon canopy death. My research takes a ground-truthed, landscape-level approach to modelling, predicting, mapping, and prioritizing stands for salvage or rehabilitation. The resulting model, derived from recursive partitioning of data from 964 sample plots, created a landscape level output with a predictive accuracy of 78%. Across the Sub-Boreal Spruce study area, I estimate that 58% of mature pine-leading stands (approximately 840,000 ha) are likely or very likely to be stocked with at least 600 stems/ha of living understory trees. --Leaf ii.
Discipline: Geography
Content Model: info:fedora/ir:thesisCModel
Date added: 2013

Title: Development of a trace generation and analysis software for random mobility models.
Contributors: Xiang Cui (author), Alex Aravind (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2007

Title: Generation and analysis of realistic mobility models for mobile ad hoc networks.
Contributors: Hassan Tahir (author), Alex Aravind (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Simulation modeling is an integral part of conducting research in communication networks and distributed systems. In systems involving mobile nodes, accurate modeling of mobility has primary importance. Mobility has a fundamental influence on the behavior and performance of the system. However, only few mobility models have been used in nearly all simulations in the past. These models are simple and highly random. As a result, the simulation studies based on these random mobility models have been heavily criticized for their credibility. We feel that availability of a software tool with the following capability, at least in part, would alleviate this crisis. The software must facilitate researchers to: (i) model a wide range of mobility with varying degrees of realism (ii) analyze the modeled mobility visually and statistically and (iii) transport the mobility trace in a format that can be used in most widely used simulators. The development of a software tool with the above mentioned capabilities is the main contribution of this thesis. In this thesis, after presenting a comprehensive survey on realistic mobility models, we present a realistic mobility generator software called RLMobiGen that can be used to specify, generate, analyze, and then export the mobility trace. The mobility trace can then be used in the simulation studies of mobile ad hoc networks. RLMobiGen is a comprehensive, highly interactive, and user friendly software. --P.iii.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2011

Title: A meta-heuristic optimization tool for simplified protein structure prediction
Contributors: Gurpreet Singh Lakha (author), Alex Aravind (thesis advisor), University of Northern British Columbia College of Science and Management (Degree granting institution), George Jones (committee member), Stephen Radar (committee member)
Abstract: Meta-heuristic algorithms give a satisfactory solution of complex optimization problems in a reasonable time. They are among the most promising and successful optimization techniques. However, some problems are highly complex and require improved techniques. A careful analysis of the existing meta-heuristic algorithms and hybridization among them may facilitate the research in this direction. To test this hypothesis, the author of the thesis developed a computational tool using a few meta-heuristic algorithms where these algorithms can be analyzed in detail and possible hybridization among them can be created. As a case study, the tool is developed for simplified protein structure prediction. The proper working of the software is demonstrated by optimizing the two sets of standard benchmark sequences. Along with testing and analyzing meta-heuristic algorithms, the tool can be used for simplified protein structure prediction.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2019

Title: A model of empathy for artificial agent teamwork.
Contributors: Behrooz Dalvandi (author), Jernej Polajnar (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: This thesis introduces a model of empathy as a basis for helpful behaviour in teams consisting purely of artificial agents that collaborate on practical problem-solving tasks, and investigates whether the performance of such teams can benefit from empathic help between members as the analogy with human teams might suggest. Guided by existing models of natural empathy in psychology and neuroscience, it identifies the potential empathy factors for artificial agents, as well as the mechanisms by which they produce affective and behavioural responses. The performance of empathic agent teams situated in a microworld similar to the Coloured Trails game is studied through simulation experiments, with the model parameters optimized by a genetic algorithm. For low to moderate levels of random disturbance in the environment, empathic help is superior to random help, and it outperforms rational help as rational decision complexity grows, in particular at higher levels of environmental disturbance. --P. ii.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2013

Title: Dance training and feedback system using wearable wireless sensors.
Contributors: Baldeep (author), Alex Aravind (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Teaching and learning the art of human body motion practices such as dance are interesting activities and they are usually performed at traditional training centres. Nowadays, learning the art of dance is becoming challenging proposition with a huge time and energy commitment. In recent times, there has been a vast advancement in computing and sensing technologies, and they are easily accessible. Based on these observations, we proposed a wireless sensor-based dance training and feedback system, which is convenient, flexible, and portable. This system is unique in terms of providing prompt feedback with various teaching and learning flexibilities to both trainees and trainers. In this thesis, an architectural framework of generic body movement training system, proposed in [1], is tuned and expanded to develop a dance training and feedback system. The proposed feedback system and its prototype implementation is the main contributions of this thesis. The proposed teaching and learning tool presents a method for generating meaningful feedback by capturing and analyzing the motion data in real time. The usage of the proposed system is demonstrated using Tap dance. Performance metrics are devised to evaluate the performance and a weighted scoring scheme is applied to compute the performance. The functionalities of the feedback system are illustrated using suitable scenarios. A combination of quantitative and qualitative feedbacks can be generated and presented to the trainees in three different forms: textual, graphical, and audio. The system also accommodates varying teaching styles and preferences of different trainers. We believe that such a two-end customization is a unique feature of the proposed system. With further tunning, we expect it will be a useful tool for teaching and learning of dance at the beginner's level.
Discipline: Computer Science
Content Model: info:fedora/ir:thesisCModel
Date added: 2013