DalSpace Institutional Repository
DalSpace is a digital service that collects, preserves, and distributes digital material produced by the Dalhousie community.
- To learn about content guidelines, policies, and how to deposit, view the Help documents.
- Contact us to get started submitting content to DalSpace at dalspace@dal.ca
Communities in DSpace
Select a community to browse its collections.
Recent Submissions
Beyond Monocular Vision: Assessing LLaVA's Performance on an Augmented CLEVR-like Dataset with Binocular Images
(2025-07-07) Devesh, Sagar; Not Applicable; Master of Computer Science; Faculty of Computer Science; Not Applicable; n/a; Not Applicable; Vlado Keselj; Hassan Sajjad; Frank Rudzicz
This thesis investigates how binocular vision impacts the spatial reasoning capabilities of Large Language and Vision Assistant (LLaVA) models in visual question answering tasks. By developing BiCLEVR, an augmented CLEVR-like dataset featuring stereoscopic image pairs and expanded visual attributes, we systematically evaluate the effect of different visual inputs across varying model sizes. Our experiments compare two LLaVA variants (7B and 13B parameters) across three dataset configurations: standard CLEVR, monocular BiCLEVR, and binocular BiCLEVR. Results reveal a nuanced relationship between model capacity and the ability to leverage stereoscopic information. The larger model demonstrated significant performance improvements with binocular input, while the smaller model showed degraded performance, suggesting insufficient capacity to process the additional visual information effectively. Particularly notable were improvements in numerical comparison and counting tasks for the larger model, indicating that stereoscopic cues enhance object individuation abilities. These findings contribute to our understanding of how vision-language models process spatial information and provide a pathway toward more robust visual reasoning systems capable of understanding 3D relationships in complex environments.
Active Removal of Tumbling Orbital Debris Using an Autonomous Chaser Vehicle in the Presence of Perturbations
(2025-07-02) Adolph, Mathew; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; n/a; Not Applicable; Dr. Guy Kember; Dr. Darrel Doman; Dr. Mae Seto
To address and abate the issues related to uncontrolled debris in orbit around Earth, active debris removal (ADR) is imperative. To perform ADR, a chaser satellite is used to rendezvous and capture the debris. Docking with debris is difficult as it is rotating about multiple axes; this is known as tumbling. This thesis details the development of an autonomous flight control strategy that attempts to synchronize and dock with tumbling debris in orbit to facilitate capture. The control strategy employs a model predictive control algorithm to predict the future state of the chaser and debris while simultaneously layering a separate closed-loop attitude controller to orient the chaser towards the debris. The control strategy was shown to successfully dock to debris tumbling at 2.6 deg/s with a 0% failure rate when at an initial separation of less than 25 m from the debris. The chaser was also able to reliably dock in less than 5 minutes to debris tumbling up to 4.5 deg/s when initially positioned 2.45 m from the debris. This research demonstrates that a single control scheme can potentially be used to successfully service a wide variety of candidate debris missions and docking conditions. The control strategy also demonstrates disturbance rejection, including recovery from a simulated micro-asteroid impact. The implemented algorithms were developed to integrate with a planar air-bearing testbed for future validation of the control strategy using hardware.
FRONTAL PLANE LANDING MECHANICS AND GLUTEUS MEDIUS MUSCLE ACTIVITY IN INDIVIDUALS RETURNED TO SPORT POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
(2025-07-09) Galloway, Ewan; Not Applicable; Master of Science; School of Physiotherapy (Rehabilitation Research); Received; Dr. Christopher MacLean; Not Applicable; Dr. Rebecca Moyer; Dr. Scott Landry; Dr. Derek Rutherford
Knee injuries, particularly to the anterior cruciate ligament (ACL), are common and can negatively impact joint health. These injuries often occur during high-impact movements, such as landing from a jump. While jump landings are used in rehabilitation and return-to-sport protocols, current assessments lack sensitivity in identifying individuals at risk. This thesis investigated differences in peak frontal plane projection angle (FPPA) and gluteus medius (GMed) activity during single-leg landings, as well as the relationship between FPPA, GMed activity, and hip abductor strength. Twenty-five individuals post-ACL reconstruction (ACLR) and 25 asymptomatic controls performed single-leg drop landings and maximal voluntary isometric contractions. No significant differences in peak FPPA were found between groups, but the affected limb in the ACLR group showed greater FPPA than the unaffected limb. No group differences were observed in GMed activity. However, lower GMed activity and hip abductor strength were significantly associated with greater FPPA.
Enhancing the Monogastric Gut Microbiome Through Innovative Nutritional Strategies
(2025-07-05) Lu, Jing; No; Doctor of Philosophy; Department of Animal Sciences and Aquaculture; Received; David Huyben; Yes; Renee Petri; Beth Mason; Vasantha Rupasinghe; Stephanie Collins
The host and microbiome can be viewed as one integrated system, which highlights the need to optimize nutrition for both the host and its gut microbiome. This thesis explored the use of nutritional strategies as selective forces to support gut microbiome diversity and resilience and ultimately improve host health and adaptability, particularly in those facing loss of host genetic and microbial diversity. Two model species, chickens (Studies 1 and 2) and polar bears (Study 3), were used to investigate gut microbiome modulation from developmental (early life vs. adult stage) to ecological (agriculture vs. conservation) contexts. Study 1 investigated reinforcing deterministic selection during early life to facilitate a lasting gut microbiome modulation through the priority effect in broiler chickens. In ovo delivery of seaweed polyphenols significantly reduced the abundance of a necrotic enteritis-causing genus, Clostridium sensu stricto 1, in the ileum of broiler chickens by day 28 post-hatch, similar to long-term supplementation of in-feed antibiotics. Study 2 examined the role of diet as a strong selection force during the production phase in two commercial strains of laying hens. Dietary inclusion of black soldier fly larvae meal (BSFLM; 0%, 6.5%, and 13%) significantly increased cecal microbial diversity and shifted short-chain fatty acid profiles toward higher acetic acid production. The 13% BSFLM inclusion increased nitrogen and ammonia excretion, which was alleviated by protease supplementation, suggesting that increased microbial diversity may reflect suboptimal protein utilization and proliferation of proteolytic taxa. Study 3 shifted focus to wildlife and compared the fecal microbiome of wild and captive bears to understand the influence of environmental factors. Captive bears had greater fecal microbial diversity, and a distinct community structure compared to wild bears. Individual variation was the main driver of microbial differences among captive bears. Captive bears fed seaweed, a natural dietary item for wild bears, showed minimal change in fecal microbiome. Together, these findings demonstrated the potential of gut microbiome-informed nutritional strategies to promote animal gut microbial resilience across life stages and in both agricultural and conservation settings. Microbial diversity should be interpreted with functionality and interaction with the host to fully understand its implications.
Evaluation of Metal Ion-Releasing Glass Particles to Enhance Antibiotic Efficacy Against Cystic Fibrosis Infection
(2025-06-30) Wolverton, Maxwell; Not Applicable; Master of Applied Science; School of Biomedical Engineering; Not Applicable; Dr. Mark Filiaggi; Not Applicable; Dr. Daniel Boyd; Dr. Zhenyu Cheng; Dr. Brendan Leung
In cystic fibrosis (CF), thickened airway mucus impairs mucociliary clearance, leading to chronic bacterial infections that cause lung damage and respiratory failure--the leading causes of mortality in CF patients. Although antibiotics are the primary treatment, incomplete bacterial eradication can promote antibiotic resistance. This project investigates whether combining conventional antibiotics with antibacterial metal ions delivered via borate bioactive glass can improve treatment efficacy. An in vitro airway infection model was developed to mimic the CF lung microenvironment using bronchial epithelial cells, a mucus-like hydrogel, and bacteria deposited via an aqueous two-phase system. Bioactive glass formulations demonstrated additive and synergistic antibacterial effects against common CF bacteria when used with antibiotics, without harming epithelial cell viability. These findings suggest that antibiotic-glass combinations may enhance bacterial clearance in CF airway infections and reduce the risk of resistance development, offering a promising therapeutic strategy for CF patients and others vulnerable to persistent lung infections.
Clerical Marriage and the Eleventh-Century Reformers
(2025-04-07) Bouthillier, Matthew