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Mechanical Performance of Foam-Infilled 3D-Printed Corrugated Core Sandwich Panels: Experimental and Numerical
Get PDFThis study investigates the mechanical performance of 3D-printed corrugated core sandwich panels under compression and bending loads through experimental and numerical methods. Initially, panels were fabricated with polylactic acid (PLA) skins and cores featuring triangular, trapezoidal, rectangular, and circular geometries. Experimental testing revealed that rectangular cores exhibited the highest compression strength, while triangular cores performed best under bending due to their superior stiffness-to-weight ratio. The circular and trapezoidal cores were found to maintain median performance under both compression and bending. Various failure mechanisms were observed within the corrugated core samples, including buckling, delamination, and core fracture. Subsequently, recycled polyethylene terephthalate (PET) foam inserts were added to the corrugated core channels to further improve the performance of the panel. The foam, recognized for its high strength-to-weight ratio, moisture resistance, and thermal insulation properties, significantly increased the compressive strength of the panels by 200-345% with only a 32.5% increase in weight. Similarly, the flexural strength improved by 170-267% while the weight increased by an average of 40%. The foam inserts delayed buckling, improved structural stability, and enhanced the ability of the panels to absorb energy under load. With the addition of foam failure, mechanisms such as foam fracture, densification, and foam shear were observed. Ultimately, finite element models were developed on ABAQUS for each core geometry. These models enabled the simulation of both compression and bending performance, evaluating the effect of change in geometric parameters and optimizing corrugated core structures. The model's predictions were validated against experimental results, showing good correlation and providing insight into how different geometries influence mechanical behavior. The simulation helps identify optimal designs for enhanced load-bearing capacity and energy absorption by adjusting core geometry. These results emphasize the importance of core geometry and foam inserts in optimizing sandwich panel designs for multi-functional and high-performance applications within diverse industries
Mapping Resonance: Tracing the Senses Communicating in the Spaces Between Deaf and Hearing People
Get PDFThis research seeks to trace how communicating feels, smells, tastes, sounds and looks in the spaces between deaf people and hearing people. By shifting the focus from “barriers” to spaces, from limitations to relationalities, and way from auralism and phonocentrism towards a polysensory understanding of communication, this thesis breaks with the conventional constructions of the hearing/not-hearing nexus, and opens up many new prospects for interpersonal and intersensory interaction between hearing people and deaf people. This creative and community-engaged ethnographic project was an inter-sensorial exploration that included eleven participants across four languages: English, French, American Sign Language (ASL), and Langue des signes québécoise (LSQ) as well as multiple language modalities, written, spoken, and signed. The first phase explored a social-institutional context and involved conducting two semi-structured interviews with two deaf university students who pursued human rights complaints against the same university after being denied access to sign language interpretation—even as their respective cases occurred twenty years apart. The second phase explored a social-creative context and involved conducting two focus groups, each participant exploring their own sense of communicating across deaf and hearing spaces. In each phase, participants described their narratives and experiences through visual, tactile, and auditory mediums, including narratives, maps, collages, video, sign language poetry, objects, and illustrations. Next, situational and relational mapping methods were employed to trace the experiences sensorily and multi-modally. Findings suggest that in contrast to popular transactional communication models, there are no barriers or gaps to communication; communicating is a persistent, inter-sensory experience that exists in the relationships between people and their environment, and occurs across time and space. In this light, new conversations are needed regarding our accountability to these relationships and how these inter-sensory spaces of communication impact our individual and collective well-being
Predicting User Performance for the Evaluation of User Interfaces in Immersive Augmented Reality
Get PDFAugmented Reality (AR) is defined as the enhancement of the user's view with interactive, computer-generated content, and arises in several forms, including Mobile AR, Spatial AR, and notably, Immersive AR. Among these, immersive AR has piqued considerable attention from both academia and industry. It enables users to immerse themselves in virtual content registered to real-world objects through head-mounted displays (HMDs) and optics technology. Providing robust interaction with virtual objects has necessitated immersive headset designers and producers to develop a broad array of interaction techniques and input modalities, enabling users to experience both a natural interaction with virtual objects and a profound sense of presence. Well-known companies in this domain, such as Microsoft, Meta, Apple, and Magic Leap, have pioneered various interactions and input modalities such as hand gestures, head pointing, eye tracking, and voice commands. The current state of the art indicates that specific input modalities, like hand gestures and head pointing, can increase both the physical and mental workload on users, subsequently increasing the error margins in object selection and manipulation within immersive environments. In response, this research adeptly applies statistical and contemporary machine learning techniques to establish guidelines for immersive AR environment designers and developers, aiming to mitigate the effects of physical and mental workload on users, particularly during hierarchical menu selection tasks, a commonplace activity in various computer applications, including immersive AR. This thesis, embodied by four research papers, extends guidelines and recommendations for designers and developers of immersive AR headsets, endeavoring to alleviate workload and error rates induced by natural interactions such as hand gestures and head pointing while performing hierarchical menu selection. The initial research focused on identifying the most efficient combination of hierarchical menu types, like radial and drop-down menus, and input modalities, such as hand gestures and head pointing in terms of workload and performance measures. The subsequent study deployed a machine learning approach, leveraging semantic encoders and the standard cognitive performance test, WAIS-IV, to predict human performance in an immersive AR environment during hierarchical menu selection tasks. The third research introduces an analysis and index for error rate in hierarchical menu selection, utilizing both subjective and objective data derived from the users. The final research is an analysis of head pointing and hand gesture path data during menu selection tasks, elucidating an index and its relationship with both subjective and objective methods for calculating workload and error rate in immersive AR
The Impact of Background Complexity on Social Media Engagement and Purchase Intentions: The Role of Influencer Type and Sponsorship Disclosure
Get PDFAs social media continues to play an increasingly prominent role in people’s daily lives, numerous brands leverage sponsored content on these platforms to garner attention and attract potential consumers. In this research, I focus on understanding how the background complexity of images used in social media posts can influence both social media engagement and purchase intentions. In a first study, I investigate the potential moderating role of influencer type on the impact of background complexity on social media engagement, as well as purchase intentions. In a second study, I analyze whether sponsorship disclosure plays a moderating role in this interaction. The findings revealed that background complexity did not significantly impact social media engagement or purchase intentions. Furthermore, influencer type and sponsorship disclosure did not have a significant influence on these outcomes. Despite this, my research still offers valuable insights and avenues for future research. Specifically, this research suggests various practical implications for brands and marketers when crafting sponsored content for social media platforms. It also sheds a light on the roles of background complexity, influencer type, and sponsorship disclosure in shaping individuals’ social media engagement and purchase intentions
Recording to See, Editing to Notice, Noticing to Learn: Experiencing a Weird Summer Through Experimental Video
Get PDFThis thesis is an account of my experience of living-with a place through Research-Creation and Heuristics. During the summer of 2023 I walked and recorded the city of Montreal, exploring what experimental video could teach me about being in a place and what it might inform my pedagogical thinking and future practice. While recording every day and returning to the archives, I created four experimental videos, six post-edition images from the stills included as In-between sections connecting chapters along the text, and an art website. All these Research-Creation results relate to the experience of feeling a place and climate change. Noticing those sometimes small or big, yet always heavy differences from day to day, mingled with what is expected of a season, concepts of grief of landscape, weirdness and living-with are strongly connected to the findings. This thesis concludes with the conception of a teaching philosophy that reflects on how this research has influenced my art and educational thinking of living in the era of the Pyrocene
QUIC Protocol : Resilience against flooding attacks and defense mechanism
Get PDFQUIC is a modern transport layer internet protocol designed to be more efficient and secure than TCP. It has gained popularity quickly in recent years and has been adopted by a number of prominent tech companies. Its efficiency comes from its handshake design. The server and the client make both the transport layer acknowledgment and the TLS agreement during the same round trip. However this process makes the packets heavy and requires more processing on the server-side than TCP. This characteristic can be used as leverage by an attacker to compromise the computing resources of its victim.
This thesis investigates the resilience of QUIC Protocol against handshake flood attacks and proposes a detection mechanism (QUICShield). I conducted comprehensive experiments to evaluate the resource consumptions of both the attacker and the target during incomplete handshake attacks, including CPU, memory, and bandwidth. We compared the results against TCP Syn Cookies under Syn flood attacks. The DDoS amplification factor was measured and analyzed based on the results. This work also proposes a detection mechanism based on a Bloom filter combined with Generalized Likelihood Ratio Cumulative Sum (GLR-CUSUM) to adapt to evolving attack patterns. It was implemented and deployed against real attacks to evaluate its efficiency. We showed that the QUIC Protocol design has a much larger DDoS amplification factor compared to the TCP, which means QUIC is more vulnerable to handshake DDoS attacks. However the mechanism proposed is accurate and efficient in terms of resources
Reimagining In/Visibility, Archival Practice and the Emergence of AI Cinema: An Exploration through Refik Anadol’s Artworks
Get PDFThis thesis explores the characteristics of “AI Cinema” through an analysis of Refik Anadol’s works. Integrating Artificial Intelligence (AI) in moving image art challenges the existing film theory and aesthetics and redefines the conventional boundaries of archival use in visual art. Drawing from an interdisciplinary approach, this study analyzes two installations, “Data Tunnel” and “Machine Memoirs v.2” from Anadol’s Machine Memoirs: Space exhibition, to illustrate the transformative role of AI in reimagining cinematic aesthetics and expression. The first chapter concentrates on the artwork “Data Tunnel,” delves into how AI facilitates new ways of seeing and challenges traditional concepts of visibility and invisibility in art. The second chapter extends analysis from “Data Tunnel” to “Machine Memoirs v.2” and focuses on the reconstitution of archives, highlighting AI’s role in redefining archival content from mere narrative support to foundational material for artistic creation. The concluding segment synthesizes the insights from the earlier chapters to articulate the emergence of AI cinema as a new cinematic form. It identifies the departure from traditional cinematic storytelling and aesthetics, fostering a dynamic, algorithm-driven cinematic experience. Through this exploration, the thesis aims to contribute to the broader understanding of cinema’s evolution in the digital age, particularly focusing on the role of AI in forging new forms of narrative and aesthetic expression. By focusing on AI cinema, the study adds to the limited but growing academic discourse in this area, providing a clear analysis of its unique characteristics and importance in the modern cinematic landscape
Possibilities of Public Art as an Agent of Renewal and Resistance in Pointe-Saint-Charles
Get PDFThis thesis explores understudied public art histories in the traditionally working-class neighbourhood of Pointe-Saint-Charles in Montreal, Québec, Canada. As a community, Pointe-Saint-Charles has a strong history of grassroots, place-based activism. Deindustrialization, top-down urban renewal, and shifting patterns of gentrification have impacted this neighbourhood in distinct ways, necessitating community-led solutions. Drawing on critical frameworks theorizing the entanglement of public art and processes of urban change, as well as community-authored historical sources specific to Pointe-Saint-Charles, this thesis aims to explore how actors within public art practices, such as artists, funders, and residents, negotiate a sense of place (Massey) within urban change. How can these different perspectives illuminate the sites and stakes surrounding public art in this neighbourhood? By exploring the conditions of commissioning, creation, and reception surrounding four public artworks installed or created over the last 50 years, this study reveals collective, personal, and political narratives of place, urban change and community spirit in a very unique neighbourhood in Canada. Informed by Elaine Speight’s concept of “place-listening,” this thesis proposes new methodologies that weave together the situated knowledge (Haraway) of long-term residents with archival research to resist dominant narratives of place, in favour of situated perspectives in Pointe-Saint-Charles
“Air-Conditioning” America: Infrastructural Imaginaries of the Air Age, 1927–1945
No full textAirplanes offered a new form of perception that was not just looking down to the earth from high above the clouds or in orbit, but also standing on the ground, looking up. Airplanes taught observers a new way of learning, absorbing information, and being in the world. In the early decades of aviation, civilian, military, and government programs organized and trained children and adults for the requirements (real and imagined) of the coming air age. These organizations, from the local to the national level—the Boy Scouts, the Civil Aviation Administration, the Ninety-Nines, the Army Air Forces, and the Navy—created communities that supported and developed aviation infrastructure. This dissertation focuses on the age-specific and gendered social labour to imagine, map, and defend the sky and airspace, highlighting how aviation impacted conceptions of scale, from Lindbergh’s flight across the Atlantic to the end of the World War II.
The first chapter traces the Boy Scouts’ changing ideal of the pilot and the role of boyhood in aviation from Charles Lindbergh through WWII. It looks at how the sky was both imagined as a new frontier for exploration and domesticated and tamed for youth consumption. The second chapter focuses on the development of both commercial and private aviation infrastructure in the interwar period, and the efforts of the women aviators in the Ninety-Nines to build air markers. At stake were two ideas of transportation, and the implications that had for the freedom of the sky. The third chapter examines the Air Warning Service, the Army Air Forces’ domestic defense effort, which asked civilians to watch the skies and track flights across the United States. Both a technical and a social network, the program balanced gendered efforts to bring military values into the home and provide homeland protection. The last chapter examines the multiple ways air recognition was taught during World War II to both civilians and enlisted personnel, focusing on the flash recognition program developed for the military. These efforts reshaped perception to reflect the needs of an increasingly interfaced sky, for a technologically militarized world
Beauty in the Eyes of the Colonizer: Unravelling the Symbolic Violence in Beauty Filters
No full textIn 2017, Instagram introduced Facial Recognition Technology (FRT) to its platform by integrating “effects” also known as filters on social media. This innovation allows users to alter, modify, and augment their image—and, subsequently, their reality. In 2020, the app’s popularity led to the production of a Peer-to-Peer (P2P) Artificial Intelligence (AI) creation hub known as the Effect Gallery. Among women, one of the most popular categories of filters is beauty effects. These simulate the appearance of a makeover and include wide eyes, long eyelashes, small noses, large lips, and clear skin. Collectively, these effects simultaneously racialize and homogenize ethnic and European characteristics by simulating a racially ambiguous mask that users can employ to disguise their natural selves. Through a selective walkthrough method and a critical comparative semiotic analysis, I examine how beauty filters reinforce and perpetuate whiteness, femininity, and racial stereotypes through the illusion of beauty contributing to a colonial legacy. Furthermore, I explore how these filters affect the racialized habitus by identifying how these representations are potentially symbolically violent to Asian female diasporic users online