University of Lethbridge Theses
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- ItemA recursive construction for some combinatorial designs(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2023) Kordani, Alieh; University of Lethbridge. Faculty of Arts and Science; Kharaghani, HadiFollowing Ionin's modified version of a result of Rajkundlia, generalized Hadamard matrices are applied to recursively construct a class of embeddable quasi-residual balanced incomplete block designs (BIBDs). The construction leads to incidence matrices related to the designs with classical parameters. Further, by a similar method and application of Paley matrices the class of balanced weighing matrices with classical parameters are reconstructed. Later in the thesis, following an approach by Ionin, the constructed quasi-residual BIBDs are extended to larger quasi-residual designs. Lastly, employing Kharaghani et al. idea a class of orthogonal arrays is used to show that the constructed quasi-residual designs are embeddable and the Ionin's class of symmetric designs are reconstructed.
- ItemEquivariant resolutions of singularities for orbits in generalized quiver varieties arising in the local Langlands program for p-adic groups(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2022) Benesh, Joel L. E.; University of Lethbridge. Faculty of Arts and Science; Fiori, AndrewIn this thesis, we investigate geometric aspects of the Langlands parameters arising in the local Langlands Program for p-adic groups. This work was inspired by David Vogan’s “The Local Langlands Conjecture”, and we built off of the work of Clifton Cunningham, Andrew Fiori, Ahmed Moussaoui, James Mracek, and Bin Xu in their book “Arthur Packets for p-Adic Groups by Way of Microlocal Vanishing Cycles of Perverse Sheaves, with Examples”. This thesis follows the construction detailed in Part II of their book, and we give more concrete examples to demonstrate their construction. Additionally, we provide an exposition on the local Langlands program for p-adic groups and give an algorithm for computing the resolutions of singularities arising from the study of the orbits of certain generalized quiver varieties for their respective Langlands parameters in the groups GLn, SOn, and Sp2n.
- ItemDetecting inaccurate stack traces in bug reports(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2022) Bheree, Meher K.; University of Lethbridge. Faculty of Arts and Science; Anvik, JohnThe generally held opinion in the software engineering community is that incorrect information in bug reports is often found in non-structural fields such as bug descriptions and steps to reproduce. However, structural information such as software stack traces can be inaccurate, increasing the project costs due to wasted time in fixed faults. Regarding the occurrence of inaccurate stack traces in bug reports, there is little empirical evidence. Therefore, we seek to provide such evidence by conducting an empirical study on the bug reports containing stack traces from the Eclipse and Apache projects. We propose an approach to classify the stack traces as either “Accurate” or “Inaccurate” by comparing the file names found in a stack trace in a bug report and the corresponding commit history for its fix. Thus, we determine the occurrence of inaccurate stack traces and identify the frequently occurring exception types that appears in the inaccurate stack traces for each project. Finally, we investigate training three supervised machine learning algorithms (Naive Bayes, Support Vector Machines and Logistic Regression), on features extracted from stack traces to create recommender that labels stack traces in bug reports as either ”Accurate” or ”Inaccurate”. The Logistic Regression algorithm was found to perform better with a F1- score up to 87% for the investigated Eclipse projects and 96% for the investigated Apache projects.
- ItemInflows of foreign direct investment to ECOWAS countries: an empirical analysis(Lethbridge, Alta. : University of Lethbridge, Dept. of Economics, 2022) Omosefunmi, Tolulope B.; University of Lethbridge. Faculty of Arts and Science; Ghazalian, PascalThe importance of Foreign Direct Investment (FDI) for economic growth and development is much discussed in the economic growth and development literature. Inward FDI provides a source of capital for host countries, and it is particularly beneficial for developing countries through knowledge spillover, advanced technology transfers, and employment creation. The Economic Community of West African States (ECOWAS) is one of the main regional trade blocs in Sub-Saharan Africa (SSA), and it is primarily distinguished by having the greatest levels of FDI inflows among geo-economic regions in SSA. While there have been general increases in inward FDI over time, there remain various economic and political challenges and broad potentials to stimulate inward FDI to the ECOWAS region. This thesis investigates the determinants of FDI inflows to ECOWAS countries using panel dataset covering various countries and spanning from 2001 to 2019. The empirical research particularly focuses on the effects of trade openness and economic growth, among other factors, on FDI inflows to the ECOWAS region. Pooled Ordinary Least Squares (OLS), panel data random effect, and panel data fixed effect estimators are used to implement the regressions, and various empirical equations are specified. The empirical analysis initially executes the regressions for a sub-dataset that exclusively covers ECOWAS countries. Then, the empirical analysis is implemented for a broad dataset that covers a range of developed and developing countries to benefit from variations in the dataset. The main empirical results show important positive effects of trade openness on FDI inflows to the ECOWAS region. It also shows positive effects of economic growth, economic development, and infrastructure on FDI inflows to the ECOWAS region. These findings highlight the particular significance of trade openness and economic growth policies in stimulating FDI inflows to the ECOWAS region. Also, ECOWAS countries should adopt policies to achieve higher levels of economic development that is accompanied with improvement in economic and financial institutions, increases in human capital, and more developed infrastructure.
- ItemSelective attention for audiovisual integration of speech(Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience, 2022) Boutros, Sylvain John; University of Lethbridge. Faculty of Arts and Science; Tata, Matthew S.The perceptual brain decomposes the audiovisual world into a set of audiovisual features such as color, shape, and pitch. An important question in perception science is whether selective attention is required to bind audiovisual features back into unified perceptual objects. In visual displays, targets defined as conjunctions of bound features typically cannot be searched for in parallel across a complex scene. Instead, attention must be scanned through a visual scene to find such targets. This means that conjunction of features requires selective attention. Only a few prior studies have investigated this process in the crossmodal audiovisual case. These prior studies left some ambiguity as to how temporal dynamics interact with selective attention, and none have used dynamic audiovisual speech as stimuli. In two experiments, this thesis explored whether the crossmodal conjunction of audio and visual speech features requires selective attention. In Chapter 2, we presented observers with displays of multiple visual faces and one audible voice. The task was to determine whether one of the faces was saying a sentence that matched the voice. In Chapter 3, we presented observers with displays of multiple audible voices and one visual face. Similarly, the task was to determine whether one of the voices was saying the sentence that matched the lip movements of the visual face. We compared response times to complete the task as the number of distracting items was increased. We found that it took longer to complete tasks with increasing number of distractors. This means that audiovisual speech targets cannot be registered in parallel across the scene and strongly suggests that selective attention is required to bind speech features across modalities.