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Recent Submissions
An Optimization Framework for Next-Generation Video Streaming Systems
(2025-06-30) Hedayati Majdabadi, Reza; Wang, Mea; Rakai, Logan; Zhao, Richard; Krishnamurthy, Diwakar
The rapid expansion of internet connectivity and digital media consumption has firmly established video streaming as the dominant contributor to global internet traffic. With the advent of immersive formats such as 360-degree and volumetric video, user experiences are shifting from passive viewing to interactive, spatially-aware engagement. However, these advanced formats introduce significant challenges, including extremely high bandwidth demands, real-time processing constraints, viewport prediction inaccuracies, and unpredictable user behavior in three and six degrees of freedom (3DoF and 6DoF) environments. The growing adoption of such technologies has placed considerable strain on existing network infrastructures and streaming platforms, exposing critical limitations in scalability, responsiveness, and quality assurance. Despite temporary mitigations—such as lowering streaming resolution—users often attribute service degradation to Internet Service Providers (ISPs), underscoring the urgent need to better balance Quality of Service (QoS) and Quality of Experience (QoE) in bandwidth-constrained and dynamic environments. This thesis presents a dual-layer optimization framework to address these challenges at both the application and network layers. At the application layer, two frameworks—Opt360 and OptVV—introduce real-time optimization models tailored to immersive media. Opt360 enforces stall-free playback as a strict constraint, accounting for dynamic viewport changes and prediction inaccuracies. It also introduces a staged streaming enhancement to the DASH protocol to improve the quality of field-of-view (FoV) content. Experimental results show that Opt360 ensures seamless playback, remains resilient to head movement variations, and maintains high video quality across fluctuating bandwidth conditions. OptVV extends this approach to volumetric video streaming, offering a comprehensive optimization model built around three components: (1) adaptive QoE optimization to balance video quality and resource efficiency in real time; (2) a DASH-based scheduling strategy tailored to the unique demands of volumetric content; and (3) resource-aware decoding optimization for managing computational complexity. Evaluations reveal that OptVV achieves up to 80% bandwidth savings, 177% improvement in viewport quality, 51\% fewer playback stalls, and 72% faster decoding performance compared to existing solutions. At the network layer, this thesis introduces SOFT-Stream, a scalable, SDN-enabled optimization framework for managing DASH sessions in large-scale ISP environments. SOFT-Stream jointly optimizes the quantity and quality of concurrent streaming sessions, while addressing practical concerns such as dynamic session behavior and real-time optimization overhead. Experimental validation shows that SOFT-Stream outperforms conventional network resource management schemes, delivering a 52% increase in session acceptance, a 200% improvement in bandwidth allocation, a 70% reduction in bandwidth wastage, and a 77% speed-up in computation time. The framework also delivers consistently smoother playback and enhanced end-user experiences across varying network conditions. Together, the contributions of this thesis offer a robust, end-to-end solution for next-generation immersive video delivery.
Linearization of Wireless Transmitters Using Blind Digital Post-Distortion Techniques
(2025-07-08) Dalbah, Ahmad Ibrahim R; Ghannouchi, Fadhel; Helaoui, Mohamed; Belostotski, Leonid; Wu, Huaqing
Nonlinearity in power amplifiers (PAs) severely degrades wireless communication signals through distortion and spectral regrowth, posing significant challenges. Currently, the only robust solution to PA nonlinearity is digital pre-distortion (DPD). While digital post-distortion (DPoD) may offer an alternative, conventional DPoD methods often rely on prior PA knowledge or extensive training data, hindering their practical applications. This thesis introduces a novel, blind frequency-domain algorithm to reconstruct distorted orthogonal frequency division multiplexing (OFDM) signals without requiring prior PA information or training sequences, proving effective across diverse transmission scenarios. For single-input-single-output (SISO) systems, the reserved-subcarrier blind DPoD method is proposed, and it employs a polynomial model to estimate nonlinear distortion by analyzing reserved out-of-band (OOB) components generated by the PA. The proposed approach has been shown to reconstruct heavily distorted signals, even with wide bandwidth and significant memory effects, demonstrating superior performance—for instance, improving EVM from over 4.5% to nearly 2% under the challenging nonlinearity of a 20-watt Doherty PA. The algorithm maintains efficacy using only a subset of reserved subcarriers, offering flexibility for real-world constraints. The approach extends to multi-layer multiple-input-multiple-output (MIMO) systems. Tested via simulation in configurations up to 16x16 antennas and 4 data streams (layers), the method effectively addresses both linear crosstalk in frequency-selective channels and nonlinear crosstalk via a proposed DPoD scheme. Measurements further validate its efficacy in a 2-layer 2x2 Doherty PA system. Finally, the proposed DPoD framework is extended to mitigate cross-modulation distortion in concurrent multi-band scenarios arising from PA nonlinearity and concurrent multi-band interactions. This proposed model is evaluated using wideband PA measurements under various conditions, including arbitrary and harmonically related concurrent multi-band signals. The technique’s power scalability is assessed, and a partitioned linearization scheme is presented using low-complexity DPD at the transmitter and the proposed DPoD framework at the receiver. Overall, the proposed blind frequency-domain, adaptable DPoD technique might of-
fer a cost-effective alternative for mobile and fixed broadband linearization applications. The results presented in this thesis demonstrated scalability and versatility across SISO, MIMO, and carrier aggregation scenarios, positioning the proposed DPoD method as a com-pelling alternative to conventional linearization for future wireless communication schemes or standards.
Mohan Singh Diwana’s Gobind Gītā textbook: An Analysis on the Subversion of Varṇāśramadharm a in the Sikh Tradition
(2025-06-30) Khera, Raymon Singh; Framarin, Chris; Adamek, Wendi; Grewal, Harjeet; Asatryan, Mushegh
This thesis examines Mohan Singh Diwana’s Gobind Gītā textbook (GGt), focusing on its portrayal of karmayoga (path of action) within the formative period of Indian nationalist and communal politics (1920-1950). It addresses the marginalization of the Gobind Gītā (GG) and the reemergence of the GGt in Sikh intellectual spaces. This occurs against the backdrop of the politicization of the Bhagavad Gītā (BG) as a unifying text for Indian nationalist identity and the GG’s subsequent exclusion from the standardized Dasam Granth (DG) by the Sodhak Committee. I argue that Diwana contextualizes the GGt to safeguard a pluralistic vision grounded in Gurmat against interpretations of karmayoga in the BG that supported varṇāśramadharma , connecting it to a Vedānticized Indian nationalist identity formation. The thesis concludes that the GGt presents a unique understanding of karmayoga based in Gurmat (Sikh worldview) and Gursikhī (Gurmat lived experience), actively rejecting the socioreligious institution of varṇāśramadharma (hierarchical sociopolitical system). This thesis employs a historical hermeneutic approach and comparative literary analysis by focusing on chapter three “Karmayoga da updesh” of the GGt, analysing Diwana’s introduction, verses, and biography. The concept of kathā (dialogical exposition) is also used to understand the GGt’s structure and its critique of varṇāśramadharma . This thesis begins by contextualizing GGt's emergence, while outlining the argument and methodology. Then, this thesis explores karmayoga in the Bhagavad Gītā to establish its textual connection with varṇā śramadharma and to contextualize its role in nationalist interpretations. Next, this thesis analyzes the GGt’s portrayal of karmayoga, arguing that it embodies Gurmat and Gursikhī through practices like nām simran (remembrance of the divine name), kīrtan (singing hymns), and kathā , alongside an egalitarian Khalsa (spiritual-military order) ethos. This thesis contributes to Sikh Studies by reinserting Diwana’s work into scholarly discourse and reasserting a Sikh pluralistic vision against prevailing varṇāśramadharma based BG interpretations.
Experiences of Continuity of Care in Relation to Emergency Department Encounters for People with Kidney Failure: A Qualitative Study
(2025-06-26) Kotani, Hana; Elliott, Meghan; Harrison, Tyrone; Thompson, Stephanie
Background: People with kidney failure have complex care needs and use the emergency department (ED) at high rates. Little is known about how continuity of care (CoC) relates to ED care seeking for patients with kidney failure. Objectives: To understand the experiences of CoC (i.e., relational, informational, and management) among adults with kidney failure in relation to their recent ED encounter. Methods: Using a qualitative descriptive methodology, we purposively sampled adults with kidney failure (defined as eGFR < 15 mL/min/1.73m2 or receipt of maintenance dialysis) from Alberta who accessed the ED for a non-life-threatening indication within the preceding six weeks from May 2024 until January 2025. We conducted individual semi-structured interviews and analyzed transcripts using a framework analysis approach. Findings: 29 participants were included (12 in-centre hemodialysis, 1 in-centre hemodialysis nocturnal, 7 peritoneal dialysis, 5 home hemodialysis, and 4 without kidney replacement therapy). Themes were identified within CoC types and across before-acute care, during acute care, and after-acute care settings. Under relational continuity, key themes included: stability and trust in care teams, disrupted therapeutic relationships, and re-establishing engagement in circles of care. For management continuity, themes included: safeguarding kidney supports and kidney care fragmentation in the ED. Within information continuity, themes included: patients as continuity self-advocates, bridging care through information sharing and extending continuity beyond the ED. Conclusion: Participants expressed varied experiences of CoC and identified important gaps surrounding emergency care. Strategies addressing perceived gaps in management and informational continuity across both outpatient and acute care settings may help mitigate the burden of ED and acute care use for people with kidney failure.
Design Innovation & Social Sustainability: Framework for Mixed-Income Affordable Housing
(2025-07-08) Hatami, Bita; Tsenkova, Sasha; Monteyne, David; Macedo, Joseli; Tawab, Hlimi
This thesis explores the intersection of urban design and social sustainability within the context of mixed-income affordable housing. Confronting the persistent challenges of housing inequality and spatial segregation, the research aims to develop and operationalize a dual-framework model that integrates spatial design principles with social sustainability goals. Grounded in interdisciplinary literature and informed by multi-level Canadian housing policies—particularly those of Calgary—it defines core social sustainability dimensions such as equity, inclusion, cohesion, and well-being. These are then systematically aligned with actionable design principles to support mixed-income housing as a vehicle for socially resilient urban communities. The study culminates in a suite of practical tools for planners, designers, and policymakers, offering structured pathways for pre-design planning, evaluation, and implementation. By positioning design as a strategic enabler rather than a secondary concern, the thesis reasserts the critical role of spatial thinking in advancing inclusive and sustainable housing futures.
