OPUS: Open Ulethbridge Scholarship

Open ULeth Scholarship (OPUS) is the University of Lethbridge's open access research repository. It contains a collection of materials related to research and teaching produced by the academic community.

Self-archiving your research in OPUS is one way to meet Open Access policies of granting agencies. It is important to retain your final, post-peer-reviewed drafts for submission to OPUS, as this is often the only version publishers will allow to be archived. Click here for information on the U of L Open Access Policy.

Check here for more information about OPUS.

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Recent Submissions

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A study of text summarization with graph attention networks
(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2024) Ardestani, Mohammadreza; University of Lethbridge. Faculty of Arts and Science; Chali, Yllias
This study aimed to leverage graph information, particularly Rhetorical Structure Theory (RST) and Co-reference (Coref) graphs, to enhance the performance of our baseline sum- marization models. Specifically, we experimented with a Graph Attention Network archi- tecture to incorporate graph information. However, this architecture did not enhance the performance. Subsequently, we used a simple Multi-layer Perceptron architecture, which improved the results in our proposed model on our primary dataset, CNN/DM. Addition- ally, we annotated XSum dataset with RST graph information, establishing a benchmark for future graph-based summarizing models. This secondary dataset posed multiple chal- lenges, revealing both the merits and limitations of our models.
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Cost-effective batch-based migration strategies for NewSQL-based big data systems
(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2024) Vadlamudi, Naveen Kumar; University of Lethbridge. Faculty of Arts and Science; Osborn, Wendy
Modern, high-performance applications demand scalable and efficient databases, leading to the evolution of NewSQL systems. The challenge lies in migrating data from Shardingsphere with PostgreSQL to AWS (AmazonWeb Services) cloud object storage. Implementing batch migration algorithms in Apache Spark, specifically targeting Delta Lake format, introduces complexities to ensure seamless data integration and storage within AWS environments. This thesis explores tailored batch-based migration algorithms for transferring data from Shardingsphere with PostgreSQL to AWS cloud object storage, emphasizing performance optimization by transferring the data faster. The study evaluates various batch loading techniques in Apache Spark, including sequential and concurrent strategies for shard-by-shard and aggregated-shards based algorithms. These techniques aim to maximize efficiency in storing data in Delta Lake format within AWS cloud storage, facilitating effective data management, visualization, and utilization for modern applications, business intelligence, AI and ML. Leveraging the Lakehouse architecture for integrated data processing and analytics.
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The effect of minimum wage increase on employment in Canada
(Lethbridge, Alta. : University of Lethbridge, Dept. of Economics, 2024) Quarmson, Isaac Sarfo; University of Lethbridge. Faculty of Arts and Science; Ali, Md Kamar
This research investigates the effect of minimum wage increases on employment in Canada, focusing on three age groups: 15-19, 20-24, and 15-24. The study utilizes provincial data from 1983 to 2022 and employs Neumark's (2001) pre-specified design to analyze the ratio format of the explanatory variables. Additionally, this study slightly modifies Neumark’s design to analyze the explanatory variables in a non-ratio format. The model results indicate no statistically significant relationship between minimum wage and employment for all age groups for Neumark’s (2001) pre-specified model and the modified form. The overall results suggest that firms may respond to minimum wage increases by adjusting other variables such as non-wage benefits, prices, profits, etc.
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Mental health, stress, and metabolomics in individuals with physical disabilities: the impact of a caretaker and spasticity
(Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience, 2024) Petruska, Chase A.; University of Lethbridge. Faculty of Arts and Science; Metz, Gerlinde A. S.; Montina, Tony
Individuals who are limited to a wheelchair because of a physical disability (PDis) face unique daily stressors in their lives. It is not well understood how a PDis impacts an individual's stress vulnerability and mental/ metabolic health, as well as the social repercussions it may create. This thesis investigated (1) how living with a caretaker impacts stress vulnerability, mental health, perceived social support and metabolism of those with a PDis relative to individuals who have no access to a caretaker and (2) how spastic cerebral palsy differs from non-spastic PDis regarding stress vulnerability, mental health, and if metabolic changes reflect the psychological wellbeing. The analysis of questionnaire data and urine samples has been used to quantify and conceptualize the unique mental and biological differences within the PDis population. Through the comparison of questionnaire scores, it was determined if stress vulnerability, mental health, and perceived social support differ between the groups. Nuclear magnetic resonance spectra analysis identified specific metabolites, and then statistical inference techniques were used to identify potential biochemical pathway alterations. These metabolites were also correlated with specific questionnaire scores, showing unique correlations within each group. Through the questionnaire and metabolomic analyses, a better understanding of the quality of life among individuals living with a PDis population can guide future strategies. This could be directed towards effective treatments or interventions that could be used to ensure that those who live with PDis are getting the proper support, are becoming less vulnerable, and receiving the best possible health care to live better lives where their mental and biological differences are being understood and accounted for.
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Collateral benefits: river flow normalization for endangered fish enabled riparian rejuvenation
(Wiley, 2024) Rood, Stewart B.; Hoffman, Gregory C.; Merz, Norm; Anders, Paul; Benjankar, Rohan; Burke, Michael; Egger, Gregory; Polzin, Mary Louise; Soults, Scott
Like most rivers worldwide, the transboundary North American Kootenay/i River has experienced multiple impacts including watershed developments, river channelization, and floodplain clearing, draining, and diking. Construction of Libby Dam was authorized by the 1964 Columbia River Treaty (CRT) between the United States and Canada, and in 1975 began regulating downstream flows for flood risk management and hydropower generation. Following cumulative impacts, the endemic Kootenai River White Sturgeon population collapsed and was designated as endangered in 1994 (U.S. Endangered Species Act). Subsequent Biological Opinions from the U.S. Fish and Wildlife Service prescribed Libby Dam operations to provide springtime flow pulses for sturgeon spawning. These provided the unanticipated benefit of substantial seedling recruitment of native and introduced riparian cottonwoods and willows. The regulated flow regime was further adaptively managed to provide a more normative (natural) regime, to balance ecological functions with flood risk management and hydropower generation. The broadened ecological considerations would be consistent with the proposed priorities for the modernization of the international CRT. The observed responses revealed that (1) diverse aquatic and riparian organisms are dependent on common river flow characteristics; (2) a normalized flow regime provided substantial ecological benefits; and (3) due to multiple influences, hybrid ecosystems develop along regulated rivers, with a blending of natural and altered processes and communities. For other regulated rivers, we recommend that (1) high springtime flows be allowed, as feasible; (2) followed by the gradual post-peak recession; and (3) the maintenance of sufficient flows through the warm and dry interval of mid to late summer.