Open Theses & Dissertations

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    Parental alienation: Intimate partner violence by proxy
    (University of New Brunswick, 2023-12) Ashe, Carly; Gill, Carmen
    This thesis examines interviews with nine women to explore how women experience and are impacted by parental alienation as a tactic of coercive control. Thematic analysis using NVIVO-14 software was used to identify recuring themes related to the three research questions that guide this study: how mother-child relationships are impacts by parental alienation; what resources mothers use in help-seeking; and do they experience barriers and obstacles to meaningful support in their help-seeking. Through understanding victims’ experiential perceptions of parental alienation, the key purpose of this study was aimed at better understanding how mothers victimized by parental alienation can be better supported in the future by legal professionals. Greater recognition of the pattern of coercive control, in which parental alienation occurs, was found to be needed by intervening professionals, along with further consideration towards preventative measures and more trauma-informed approaches.
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    Love at first flight: Mating errors, population genetics, and the slow spread of an invader
    (University of New Brunswick, 2023-12) Anderson, Jennifer L; Heard, Stephen B.
    This thesis investigates mating interactions and population genetics of the invasive Tetropium fuscum Fabricius (Coleoptera: Cerambycidae) and its native congener, Tetropium cinnamopterum Kirby (Coleoptera: Cerambycidae) in Nova Scotia, Canada, to help explain the slow spatial spread of T. fuscum in North America. Tetropium fuscum first appeared in North America in about 1990 and has since outcompeted the native T. cinnamopterum in the sympatric zone and spread approximately 150 km from its point of entry but has since halted its spread. Tetropium fuscum and T. cinnamopterum have common host plants, overlapping flight periods and share the same male-produced sex-aggregation pheromone, fuscumol, that attracts both sexes. These species would have ample opportunity to encounter each other in the field due to these similarities suggesting hybridization is a possibility. Our mating behaviour experiments showed males of both species make mating errors under no-choice mating conditions. Under choice mating conditions T. cinnamopterum males show a strong preference for same-species females but T. fuscum is less discriminating. We designed a species discriminating SNP assay with the goal of detecting hybridization to confirm that mating errors also take place in the field. We found low levels of introgression in the sympatric zone as well as the presence of cryptic individuals that morphologically present as T. cinnamopterum while genetically presenting as T. fuscum. We investigated the possibility that female body size rather than species influences mate choice in Tetropium. Tetropium cinnamopterum females are significantly larger than T. fuscum females although body size was not a determining factor in male mate choice for these species. Our findings suggest heterospecific matings between these species happen but may be rare and the resulting offspring may not be as fit as their parents, which could exacerbate Allee effects at the edge range of T. fuscum and reinforce its apparently pinned range border.
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    A Bloom filter based authentication scheme for vehicular digital twin
    (University of New Brunswick, 2024-03) Adeyiga, Olajide; Lu, Rongxing
    The rapid growth in the automobile industry and the competitive nature of industry players has necessitated a closer connection between vehicles and their owners. This work will explore indepth the use of a Bloom filter based mutual authentication scheme in a vehicular digital twin system. Currently research into digital twin of vehicles within the IoT space shows that vehicles require a constant means of communication with their digital twin while the digital twin also requires such means of communication with the IoVs and other Digital Twin systems. However, these systems exhibit significant security gaps. The system is currently prone to adversarial attacks like the replay, anonymity, linkability attacks among others. The goal of this research will be the implementation of an authentication scheme that provides secure connection between all entities within a vehicular digital twin network. This scheme will use user credentials and vehicle private features to achieve mutual authentication.
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    An efficient dynamic key management scheme for IoT devices
    (University of New Brunswick, 2023-10) Vikraman Pillai, Vishnu Prasanth; Lu, Rongxing
    The Internet of Things or IoT is a collective term for electronic devices with computing and connectivity. Our proposed dynamic key management scheme is designed for secure group communication of IoT devices. It offers efficient key distribution for a small to medium group of devices in domains such as centralized healthcare systems. Our key management scheme ensures forward secrecy, backward secrecy, and key independence in group communication. The scheme uses binary heap trees and bloom filters for efficient storage, organize and verification of secret keys. It uses polynomial coefficients secured with modular arithmetic to distribute the keys. The proposed implementation of the scheme uses lightweight mathematical operations such as XOR, multiplication, string concatenations, and hashing for devices having limited computing capabilities. The thesis is concluded with the performance analysis of the scheme that demonstrates the suitability of the scheme with similar IoT group communication schemes.
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    Efficient in-memory processing of SQL queries with JIT compilation
    (University of New Brunswick, 2023-12) Verma, Saumya; Ray, Suprio
    Database systems are vital to the modern world. The conventional approach to SQL query execution is to convert a SQL query into a plan tree of relational algebra operators and then interpret them over each tuple. This method has an advantage when the bottleneck is disk I/O. However, modern advances in hardware have led to faster storage systems and large main memory capacities. With in-memory query processing, the mentioned traditional approach based becomes a performance bottleneck by consuming a significant portion of query execution time. Therefore, the thesis introduces a compilation-based in-memory database system. It leverages the advantages of intermediate representation code generation for scan, filter, group-by, sort-by, aggregation, and join operations of SQL queries with Just-In-Time compilation using the Multi-level Intermediate Representation framework. Evaluation shows that compared with a conventional database system (PostgreSQL) and a high-level language (C++) code generating query processor, our proposed system performs significantly better.
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    “It’s not that hard to not commit a crime”: Distinguishing individuals who have and who have not acted on pedophilic interests
    (University of New Brunswick, 2023-12) Vander Molen, Lauryn; Ronis, Scott T.
    Little research has explored why some individuals with sexual interest in children (i.e., pedophilic interest) act on their interests whereas others do not. This dissertation examines factors that distinguish individuals with pedophilic interests who have engaged in pedophilic behaviours (i.e., engaged in child sexual abuse or viewed child sexual exploitation material) from those individuals who have not engaged in such behaviours. English-speaking participants (N = 136) with self-report pedophilic interests from multiple nations (e.g., Canada, United States, United Kingdom) were recruited via social media platforms (i.e., Reddit, Twitter, Facebook) and online pedophilia support groups and forums (e.g., Virtuous Pedophiles, NNAI Space) to complete an online survey regarding sexual interests and behaviours as well as on help-seeking experiences. Multivariate analysis of variance and discriminant function analysis indicated that factors associated historically with sexual offending in general (e.g., criminal history, hypersexuality) best differentiated individuals exclusively with pedophilic interests from individuals with pedophilic behaviours. Further, based on thematic analysis of open-ended responses, three main themes emerged reflecting participants’ (1) general distress; (2) attempts to search for meaning and purpose; and (3) characteristics contributing to offending. Overall, results suggest several avenues for future research, including conducting typographical research with individuals with pedophilic interests who have and have not acted on their interests, directly comparing criminal and community-based samples, and applying non-criminological theories to the study of pedophilic interests. In addition, qualitative findings highlight the need for mental health clinicians to increase their comfort and knowledge relating to mandatory reporting, risk of offending, and the significant mental health needs of men and women with pedophilic interests. This shift will improve well-being and access to mental health services among a highly marginalized group and may reduce incidents of sexual abuse.
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    Forestry information extraction using high spatial resolution remote sensing imagery
    (University of New Brunswick, 2023-12) Tong, Fei; Zhang, Yun
    This PhD research focuses on the development of reliable and efficient methods for individual tree crown delineation and tree species classification, which provide essential information for modern forestry management and climate change monitoring. The primary objective of this research is to develop robust methods that can accurately delineate individual tree crowns and classify tree species using high spatial resolution remote sensing imagery. By achieving this objective, the research aims to enhance the reliability and efficiency of forestry management practices and contribute to the field of remote sensing applications in forestry. For tree crown delineation task, existing tree crown delineation methods are not suitable for large areas applications, because they need highly experienced experts to manually assign suitable parameters to control the delineation results, which is time-consuming, inaccurate, and not suitable for normal users. To address this issue, this dissertation presents a tree crown delineation method utilizing marker-controlled watershed segmentation specifically designed for high spatial resolution multispectral WorldView-3 satellite imagery. To reduce the difficulty of assigning parameters, the proposed method incorporates an automated supervised search process to determine the threshold. Moreover, an enhanced definition of spatial local maximum is employed to mitigate false treetops, thereby enhancing the accuracy of treetop detection. For tree species classification task, although deep learning methods based on convolutional neural networks (CNN) have achieved promising results, challenges remain in hyperparameter tuning and the requirement for large number of labeled training samples, limiting their applicability in real-world applications. This dissertation addresses these challenges by proposing three models based on the concept of deep forest to enhance the tree species classification from high spatial resolution hyperspectral imagery. All the three proposed models only require two hyperparameters that are easy to be determined by users. To optimize the classification accuracy, two different ways to combine both fixed-size patches and shape-adaptive superpixels are proposed to fully exploit spectral-spatial information within the high spatial resolution hyperspectral imagery. To reduce the demand for labeled training samples, the active learning (AL) is perfectly integrated into the multilayer cascaded random forests classification model.
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    Indigenous electoral candidates in the Canadian media: The reproduction of the assimilationist politics of recognition
    (University of New Brunswick, 2023-10) Tagle, Seth; Everitt, Joanna
    Research on media coverage of candidates in Canadian elections has generally focused on gendered, racialized, and LGBTQIA+ candidates. Past research has found that political reporting often frames politics as a masculine, white, and heterosexual domain when candidates who do not conform to these norms are seen as novel in politics. Despite all this research into different identity groups of electoral candidates, little research has been conducted on how the media portrays Indigenous candidates. This thesis builds on the existing literature surrounding how electoral candidates are covered in the news media in order to examine the types of coverage that Indigenous candidates receive. Ultimately, I find that the news media employs moral craftwork in a manner that tends to reduce Indigenous candidates to representatives of their Indigeneity and symbols of progress and inclusion. This thereby helps to reinforce the Canadian state's approach to Indigenous assimilation through recognition.
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    An experimental investigation of the coherent turbulent structures in a controlled and uncontrolled turbulent three-dimensional wall jet
    (University of New Brunswick, 2023-10) Sim, Bonnie Caitlin McKernan; Hall, Joseph W.
    The turbulent three-dimensional wall jet exhibits significant disparity in growth, with lateral growth rate five to eight times larger than vertical growth rate. The mechanisms that cause this strong asymmetric growth are not fully understood but are known to be linked to the passage of coherent structures. The purpose of the present investigation was twofold: to further the understanding of coherent structure development in the wall jet and to apply targeted active flow control to alter these structures and the flow field. The development of coherent structures was explored experimentally through synchronized simultaneous measurements of fluctuating wall pressure and flow velocity at a Reynolds number of ReD ≈ 134, 000. Fluctuating wall pressure was measured using a two-dimensional lateral-streamwise array of 89 microphones, positioned symmetrically about the centreline from x/D = 5 to 15 between z/D = ±4. Particle Image Velocimetry was used to measure the lateral and streamwise flow velocities along a two-dimensional plane at y/D = 0.5. This plane has never been measured in the wall jet and was chosen to investigate continuous streamwise structural evolution. The measured velocity contours showed the large lateral growth. Low-order reconstructions of the instantaneous unsteady pressure field showed significant lateral asymmetry and the growth of large angled chevron structures. The estimated instantaneous velocity fields showed that these structures were intermittent, changed speed, slowed down, surged forward, and convected laterally, while growing and strengthening with downstream development. It was determined that these structures caused flapping in the jet and the large lateral growth. Targeted active control was performed using eight synthetic jets actuated around the nozzle. Experimental measurements showed that the control had a significant impact on jet development, causing an increase in lateral half-width of 80%. This level of control has not been achieved in this field to date. Compared to the uncontrolled jet, the controlled jets exhibited stronger fluctuations in the near-field, larger lateral growth at comparable streamwise positions, stronger instantaneous lateral velocities, shorter potential cores, and larger angled structures.
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    Effect of aggregate gradation changes in asphalt mix performance
    (University of New Brunswick, 2023-12) Ruiz Salom, Nora Lucía; Sanchez-Castillo, Xiomara
    The New Brunswick Department of Transportation and Infrastructure follows specifications in their Standard Specifications for Highway Construction for their road construction. Nevertheless, these specifications are 20-plus years old and there is a need to update them. This research project aims to give an insight into possible changes that these specifications could include in its updating process. To achieve this, research was conducted in a two-year master’s degree program at the University of New Brunswick. The experimental work consisted of the analysis of current guidelines, the evaluation of performance tests for common distresses from four approved mix designs, and the modification of these mix designs using conventional and unconventional tools. The outcomes of this project will be helpful to the province of New Brunswick and other Transportation Agencies, that are transitioning and updating their specifications aiming for higher-quality roads with higher resistance to common distresses such as rutting and cracking.
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    WaCadie: Towards a web corpus of Acadian French
    (University of New Brunswick, 2023-12) Robichaud, Jérémy; Cook, Paul
    Corpora are important assets within the natural language processing and linguistics communities. However, not all low-resource languages have corpus representation. Acadians, an eastern people of North America, do not have a corpus representation of their variation of French. An Acadian French corpus could allow for a better understanding of the unique dialect. Leveraging web-as-corpus methodologies such as BootCaT, domain crawling, and social media scraping, we create three different corpus representations of Acadian French. Each corpus is, on its own, an Acadian French resource while also showcasing the strengths of their individual method of creation. We propose 22 statistical corpus-based measures stemming from previously researched Acadian French characteristics to compare these newly built corpora to known Acadian French text. We found that while all three yield traces of Acadian French text, BootCaT is the largest corpus, and social media scraping has the highest count of Acadian French characteristics.
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    Minimization of net-load variance using smart EV charging algorithm
    (University of New Brunswick, 2023-10) Rahman, Afnan Rudabe; Chang, Liuchen; Cardenas Barrera, J.
    Electric vehicles (EVs) are developing faster than ever. With the increasing number of EVs and their uncoordinated charging, the additional electric load significantly impacts the distribution grid for low penetration levels. If the EV penetration level reaches a high degree for a specific regional grid, the EV load will cause more significant risks to the grid. In this research, using localized statistical information and the Dichotomous Search Method, a charging algorithm considering the charging priority is proposed to minimize the net-load variance and the negative impacts of EV load on a medium voltage distribution. The charging priority of EVs is defined according to the State of Charge (SoC), the charging time required of individual EVs, and the power generated by the local grid. Each EV is assigned a specific period to charge. This motivates minimizing the demand peak and the valley filling by shifting the EV load.
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    Purification of natural metabolites from Radula complanata and towards the elucidation of perrottetinene’s biosynthetic route
    (University of New Brunswick, 2023-12) Perley, Jacob; Qu, Yang
    The Bryophyte Radula complanata is a non-vascular plant and a unique source of medicinal metabolites. The plant is particularly rich in aromatic bibenzyls, which are likely generated to deal with environmental stressors, herbivory attacks, and plant pathogens. Particularly, the bibenzyl perrottetinene (isolated from related species R. marginata and R. perrottetii) is structurally similar to the well-known psychoactive cannabinoid tetrahydrocannabinol and is shown to have cannabinoid receptor agonism. In this study, two major bibenzyl compounds in R. complanata were purified and structurally elucidated by mass spectrometry and various Nuclear Magnetic Resonance (NMR) techniques. While perrottetinene biosynthesis remains elusive, several enzymes from R. complanata are biochemically characterized. The findings are the first steps towards the elucidation of the complete biosynthesis of perrottetinene and related bibenzyl cannabinoids.
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    Carbonized metal-organic frameworks as bifunctional electrocatalysts for oxygen reduction/evolution reactions
    (University of New Brunswick, 2023-10) Parsimehr, Hamidreza; Ignaszak, Anna
    Electrochemical energy devices like batteries and fuel cells as benign high-performance solutions for energy issues have been swiftly developed in recent decades. Both metal-air batteries and fuel cells use a positive electrode (cathode) that has a similar chemical composition to facilitate oxygen reduction reactions (ORR) during their operation. The second important reaction involving oxygen species is the oxygen evolution reaction (OER). This process is used in water electrolyzers to generate oxygen. An electrocatalyst incorporated in the electrodes in the above-listed energy systems is key to the efficient ORR and OER processes. Such electrocatalyst plays a critical role in overall performance, stability, and long cycle lifetime. The main objective is to synthesize and evaluate the electrochemical performance of heteroatom-doped carbons made by pyrolysis of metal-organic frameworks (MOFs) and zeolitic imidazole frameworks (ZIFs). Although some of these catalysts demonstrated decent activity, further work is needed to prove their electrocatalytic performance.
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    Examining and comparing the perceptions of obesity between Canadians and Nigerians: A cross-sectional study
    (University of New Brunswick, 2023-12) Olateru, Stephen; Dombrowski, Stephan
    Obesity prevalence has increased globally in the past fifty years and is predicted to increase further. Disease perception may profoundly impact health outcomes by influencing individual behaviour. This study examines and compares the perceptions of obesity between Canadians and Nigerians. Adults from Canada (n=878; mean age = 47.6years; mean body mass index [BMI] = 36.4 kg/m2 ) and Nigeria (n=516; mean age = 39.9years; mean BMI = 26.1 kg/m2 ) completed an online survey assessing levels of agreement with perceptions of obesity and weight bias. Whilst there were significant large to medium differences in the agreement with obesity messages (p<0.001), there were significant but small differences in the perceived causes of obesity (p<0.001). Both countries showed high levels of support for many obesity interventions. Canada and Nigeria showed differences and similarities in their levels of agreement with different measures of obesity perception and weight bias.
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    Impact of exercise with blood flow restriction on muscle hypertrophy and performance outcomes in men and women
    (University of New Brunswick, 2023-12) Nancekievill, Dawson Andrew; Sénéchal, Martin
    Blood flow restriction training (BFRT) improves lean mass and strength. In BFRT studies, only 17-29% of participants were female. We compared lean mass and strength following 6-week BFRT between males and females. Thirty-eight adults (age, 25.3 ± 3.1 years; female, n=19) participated. Exercises were performed at 30% of 1-repetition maximum (1-RM) and individual’s limb occlusion pressure set at 60%. Lean mass was assessed via dual-energy x-ray absorptiometry, strength was measured using 1-RM. A significant increase in lean mass was observed in males (p= .009) and females (p= .023) without group differences (p= .279). Both males and females increased 1-RM for upper-and lower-body exercises. However, there was a significant interaction effect (time x sex) for knee extension (p= .039), chest press (p= .002), and seated row (p= .033). Lean mass and muscle strength increased following six weeks of BFRT. Males may improve upper-body strength to a greater extent.
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    Discovery of natural products from marine derived fungi and endophytic fungi
    (University of New Brunswick, 2023-10) Morehouse, Nicholas J.; Gray, Christopher A.
    Natural products are an abundant source of bioactive, complex, and diverse chemical structures. This thesis describes the isolation and structure elucidation of natural products biosynthesized by marine-derived fungi and endophytic fungi with the primary objective of the research being the discovery of new chemical structures. The thesis is divided into two parts: the discovery of new natural products and the development of a new dereplication platform. Three fungal isolates were investigated to discover new natural products. First, investigation of a Penicillium sp. fungus isolated from sea foam resulted in the discovery of a new phenalenone derivative that selectively inhibits the growth of Staphylococcus aureus and Mycobacterium tuberculosis. Second, investigation of an Aureobasidium pullulans fungus isolated from needles of Thuja occidentalis (white cedar), led to the isolation of two new C11-polyketides that inhibit the growth of Mycobacterium tuberculosis. Finally, investigation of a Tolypocladium sp. fungus isolated from the marine macroalga Spongomorpha arcta led to the isolation of two new lipopeptaibols that inhibit the growth of Gram-positive bacteria and mycobacteria. Although these five natural products are new, they are structural derivatives of previously discovered molecules rather than being structurally novel. To improve the likelihood of discovering novel natural products in the future, Structural similarity Network Annotation Platform for Mass Spectrometry (SNAP-MS) was developed. SNAP-MS utilizes molecular networking topology and structural similarity fingerprinting to generate annotations of natural product compound families to aid in the dereplication process. This platform addresses limitations of many currently existing tools, such as the lack of publicly available reference data for most natural products and provides a new tool for analyzing complex mass spectrometry experiments that will improve dereplication capabilities and improve the likelihood of discovering novel natural products.
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    Impacts of noise on the response to territorial intrusions in hermit thrush (Catharus guttatus)
    (University of New Brunswick, 2023-10) Moore, Jennifer L.; Roach, Sean
    The obstacle that anthropogenic noise presents to songbird acoustic communication is well understood from the signaler perspective, but less is known about signal receivers. Using playback studies to simulate intruders on territories along a gradient of ‘urbanness’, the impact of both urban noise and experimental noise on hermit thrush (Catharus guttatus) territorial defense behaviour was quantified. Detection of the simulated intruder did not change as a result of urbanness or experimental noise. Responses to the intruder were less aggressive when experimental noise was present, but more swoops were performed near busier roads. As such, the urban anger hypothesis appears to be related to road presence, not noise level. When vocally responding to the intruder, experimental noise, but not urbanness, was associated with increased song amplitude and lower signal to noise ratio. Urban noise is less detrimental to hermit thrush than previously thought, but experimental and urban noise have different impacts.
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    The social construction of masculinity and intimate partner violence: Underestimating men’s perspectives
    (University of New Brunswick, 2023-11) Meng, Alison Marie; Holtmann, Catherine
    This thesis investigates the impact of social constructions of masculinity on men's use of intimate partner violence (IPV), addressing two questions: (1) How do social constructions of masculinity and gender influence men’s use of IPV? and (2) Based on their exposure to patterns of gender interaction, how do men learn and internalize processes that inhibit or encourage using IPV? Using Connell's (Connell & Messerschmidt, 2005), theory of hegemonic masculinity, this study analyzes the Canadian White Ribbon Campaign's "Boys Don't Cry" video through content analysis and employs it as a visual method for qualitative interviews with 16 men aged 19 to 25. Findings reveal some men make conscious choices not to use violence despite social pressures and learn through sensitizing experiences and gendered interactions with men and women that using violence leads to negative consequences. This study allowed for participants to gain more awareness about their conceptualizations of masculinity and IPV.
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    Privacy-preserving weighted Manhattan distance-based similarity query
    (University of New Brunswick, 2023-12) Mairabo, Rhoda Tani; Lu, Rongxing
    Computing over outsourced, encrypted data in an efficient, secure and privacy-preserving way continues to be a challenge as the quantity, complexity and applications of the data continue to grow. Both data owners and data users require solutions that address the continued evolution of security and privacy needs in the presence of determined malicious actors and threats. The basic framework for similarity queries has remained relatively unchanged, but we continue to design more efficient, secure and privacy-preserving schemes that combine different encryption techniques and data structures to better address the needs of the users and changing landscape of data complexity and its attendant threats. We propose and design a similarity query scheme that uses a weighted Manhattan distance-based metric, a symmetric homomorphic encryption (SHE) technique, a kd-tree to index our data and a 2-cloud server model. Security analysis shows that our proposed scheme can achieve the desirable privacy requirements.