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Otakaari 1 grandhall. Photo: Esa Kapila
 

Communities in DSpace

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Now showing 1 - 13 of 13

Recent Submissions

Advancing human–computer communication for the internet of senses: a UAV scenario
(2025) Sehad, Nassim
School of Electrical Engineering | Doctoral thesis (article-based) | Defence date: 2025-12-12
The rapid evolution in network technologies, device capabilities, Generative Artificial Intelligence (GenAI), and 5G communication have ushered in a new era of immersive multimedia applications, enabling interactive streaming, virtual collaboration, and novel forms of human–machine interaction. This evolution has enabled the emergence of the Internet of Senses (IoS), a paradigm that transcends traditional audio-visual interaction by integrating multi-sensory experiences. The IoS envisions a seamless fusion of digital and physical experiences, augmenting human senses through advanced technologies including AI, robotics, and next-generation communication systems. Potential applications span across diverse domains, such as immersive virtual tourism, remote healthcare and telesurgery, sensory-rich e-commerce, collaborative industrial training in simulated environments, and the teleoperation of robotic platforms, including Unmanned Aerial Vehicles (UAVs). By engaging multiple senses (sight, hearing, touch, smell, and taste), the IoS aims to deliver experiences that feel indistinguishable from physical reality, with far-reaching implications for accessibility, user engagement, and the development of a Digital Twin (DT) of the universe. However, realizing truly immersive multi-sensory interaction presents substantial challenges. These include achieving ultra-low latency while ensuring high Quality of Experience (QoE), optimizing bandwidth usage, synchronizing heterogeneous sensory media, and maintaining reliable transmission under high-mobility conditions. Such challenges are particularly pronounced in mobile teleoperation scenarios, especially for UAVs, where high handover rates and unreliable connections to Base Stations (BSs) in cellular networks exacerbate latency and reliability issues, making performance and precision critical for safety and operational effectiveness. This thesis addresses these issues by investigating how a platform for the IoS can be developed to extend beyond sight and hearing, enabling multi-sensory telepresence and virtual interaction. The research examines methods for reducing latency in immersive service delivery and enabling effective haptic feedback for accurate six Degrees of Freedom (6DoF) interaction. Based on these methods, a real-world testbed was implemented, on which Reinforcement Learning (RL) techniques were investigated to enhance system adaptability, and semantic communication approaches were explored for efficient compression of sensory data. The research also focuses on optimizing sensory data transmission in UAV-based scenarios to enhance remote control, user immersion, and overall quality of experience. By tackling these challenges, the thesis contributes to the development of future-ready immersive systems capable of revolutionizing human-computer interaction and redefining digital experiences across multiple industries.
Participatory design for resistance: The making of pictograms with indigenous youth in the Ecuadorian Amazon
(2025) Pinto, Nathaly
School of Arts, Design and Architecture | Doctoral thesis (article-based) | Defence date: 2025-12-12
Participatory design research and practice are increasingly engaging in efforts to reformulate and contest dominant codes in the field. This involves reassessing structures shaped by productivist logics, centralized institutions, and extractivist-capitalist worldviews that reproduce inequalities oppressing communities and territories at the margins. Responding to the pressing need to grapple with resistance by historically marginalized communities via participatory design (PD) with indigenous peoples, the thesis introduces a research and production framework grounded in emerging research/participation processes from Latin America, particularly practices of indigenous community communication. Through developing this framing – anchored in learning from and connecting with epistemologies and socio-cultural infrastructures that, though historically excluded from dominant narratives, offer vital insight and approaches to knowledge and material production – the project as a whole emphasize structuring the work for resistance as a creative and transformative force, to expand conventional design approaches and challenge extractive research logics. The study drew on a long-term collaborative project in the Ecuadorian Amazon with indigenous youth, communities, and organizations, centered on the making of pictograms to represent and reactualize situated knowledges and practices with indigenous peoples. Pictograms were mobilized as knowledge systems and political, counter-hegemonic devices grounded in heterogeneous histories, rather than as objects of prevailing “modern” design. Developing pictograms sustains collective praxis of learning from the diverse knowledges of the communities and their territories, while tying in with situated histories of collective struggle. The findings are outlined through four peer-reviewed publications, each looking at the participatory research and at the collaborative design journey from one particular perspective. Together, the findings indicate that the project moved beyond dominant modern design paradigms (which frame pictograms as extrinsic, standardizing devices for universal information/communication), positioning them instead as a living process and as situated technological and cognitive devices for collective knowledge-building. Aligning their creative practice with indigenous community communication via a crucial indigenous framework marks a path forward from conventional understandings of participation in design research and production, thereby helping shape popular, communal, and intercultural participatory approaches to design. In sum, this PD is design practice that considers the relational fabric in which it is embedded, involving diverse forms of labor beyond the designer–computer dyad. Thus, it radically challenges notions of individual authorship when production is social and communal rather than merely collective. Insight from the concept and practice of resistance with indigenous communities and territories provided a foundation for collaborative design at the margins, considering local–global ethical cum political dimensions, researcher positionality, and the histories of situated participatory praxis. The work embraces tensions as dialogical spaces that benefit the research, leveraging North–South dialogue and the material conditions that enable fruitful engagement with Amazonian nationalities. Building on this foundation, it articulates commitments to collectivity and to tensions as guiding principles for design research and production, both as a site of contestation and as a means of strengthening emancipatory practices. Committing to collectivity spotlights how co-appropriation of design efforts between the communities and the design researcher, in so called mundane and strategic work especially, decentralizes practices, with effects that configure alternative design relationships and deepen understandings of redistribution of participation – across knowledge, production, and burdens. The second framing, in turn, positions contradiction as a space for action. The necessary different positioning of the design researcher, exemplified in militant design research, expresses situated historical theorizing and enacting of political action while actively avoiding research practices that dislocate or appropriate knowledges and practices with indigenous communities/territories. The PD research and production framework proposed for resistance with indigenous communities in the Amazon opens a space for creative theoretical and material approaches to learning from and supporting other ways of being, knowing, and doing. In broader terms, it contributes to reimagining, doing, and thinking for PD otherwise. It calls on design researchers, whether working from the margins or acting across these and other boundaries/borders, to produce knowledge on terms that serve diverse communities and territories.
Nonlinear dynamics of sea ice at intermediate scales via deep learning optical flow
(2025) Uusinoka, Matias
School of Engineering | Doctoral thesis (article-based) | Defence date: 2025-12-12
Sea ice dynamics span from meter-scale engineering mechanics to basin-scale geophysics. Although extensive research has been performed at both ends of this spectrum, observations at intermediate scales are still lacking. Furthermore, to connect research on ice dynamics in engineering and geophysics, a quantitative link between these approaches is required. This research addresses the gap by analyzing the properties of nonlinear dynamics through scaling laws observed in deformation fields extracted from ship radar data. To reliably obtain strains from radar imagery, first, a deep-learning optical flow framework is developed. A novel estimate initialization technique is proposed, enabling higher accuracy with small displacements and radar noise. The framework is demonstrated to surpass the accuracy of all other methods. Based on deformation fields extracted with the proposed method from ship radar data, increased intermittency and longer quiescent periods are observed. A lower bound of the scale invariant properties from first-moment spatial scaling is observed. Seasonal analyses show robustness of this lower bound during winter. During summer, more granular behavior is observed, with negligible localization, thus defying the applicability of fractal analysis. Further analysis on the multifractal properties of the deformation fields demonstrates early-winter conditions to exhibit a quadratic form of the multifractal spectrum that is typically observed in large-scale analysis. Latewinter deformations transition toward near-monofractal or unstable patterns as the ice cover evolves. Fully developed multifractal spectra are shown to emerge only with large enough spatial and temporal domain sizes. These observations are used to extend the multifractal framework applied to ice dynamics by introducing threshold domain sizes in space and time. The threshold domain sizes are hypothesized to depend on the properties of the ice cover. The results of this work have major implications for research on ice dynamics. The developed method for analyzing motion and deformation from radar data opens new avenues for studying field data from various sources. The observations on the lower bound for scale invariance and the introduction of threshold domain sizes help model selection between discrete element and continuum models. The threshold domain sizes also indicate the possibility of reproducing largescale statistics of ice dynamics under controlled conditions in laboratory studies. The methods and findings together provide empirically grounded criteria for linking scales in ice dynamics, which affects research ranging from ice-structure interaction to numerical modeling at geophysical scales.
Hearing as intended: How differences in listening conditions affect sound translation
(2025) Riionheimo, Janne
School of Science | Doctoral thesis (article-based) | Defence date: 2025-12-12
One primary objective in sound production is to ensure reliable translation from mixing rooms to end-listening environments. Film and music makers should be confident that their mixes are heard as intended in the final playback conditions, whether in cinemas, homes, or on personal devices. However, variations in room acoustics, loudspeaker configurations, and playback systems introduce challenges that can alter perceived timbre, spatiality, and overall loudness. This thesis investigates how room acoustics and reproduction systems affect the perceptual translation of sound character across diverse listening conditions. The research is based on two controlled listening experiments: one focusing on movie sound reproduction in cinemas and mixing rooms, and the other on spatial sound reproduction in music contexts, including headphone listening. Listening environments were captured using spatial impulse-response measurements and recreated in a laboratory setting with a spherical loudspeaker array or headphones. Sound professionals evaluated perceptual attributes such as clarity, immersiveness, and brightness through carefully designed listening tests, which were analysed using statistical methods. The results show that room acoustics and reproduction format significantly influence how sound translates between mixing rooms and playback spaces. In cinema environments, excessive reverberation reduces dialogue clarity, making speech sound muddy or distant. In contrast, the frequency response and brightness dominate the perceived differences in music. Moderate reverberation can enhance listener envelopment, particularly with slower music, and adding artificial reverberation to dialogue can improve spatial translation across rooms. In spatial music reproduction, multichannel formats, such as 7.1 surround, better preserve the spatial sound character across different rooms compared to stereo, especially when sound objects are precisely positioned. Moderate reverberation (around 0.25 s) was also found to enhance clarity and proximity, and to reduce phantom-centre colouration, whereas overly dry environments can compromise listener comfort. The findings further highlight mixing challenges such as phantom-centre problems, coherent summing, and down-mixing issues that affect translation in both loudspeaker and binaural headphone reproduction. While timbral balance and loudness are primarily determined by system calibration, spatial translation depends more strongly on room acoustics, especially in the absence of surround speakers. This thesis discusses various calibration approaches and target-curve choices and examines how calibration, room acoustics, and speaker configuration influence the translation of sound character across listening environments. The work provides practical insights for optimising mixing and reproduction to improve translation.
Fabrication of multifunctional superhydrophobic surfaces
(2025) Mirmohammadi, Mehran
School of Chemical Engineering | Doctoral thesis (article-based) | Defence date: 2025-12-12
This thesis explores the development of multifunctional superhydrophobic surfaces using microfabrication techniques. It investigates a range of fabrication strategies, including replication, lithography, film deposition, and etching, to produce these robust multifunctional surfaces. The surfaces are intended for use in wear-resistant, anti-icing, and antibacterial applications. These surfaces can be achieved by applying a low surface energy coating to a structured surface and by introducing roughness, such as fabricating hierarchical micro- and nanostructures on inherently hydrophobic materials. Polymer replication, known as soft lithography or direct templating, is a highly effective technique for creating topographical surfaces from hydrophobic materials. This approach involves using original structures derived from nature or rough metal surfaces. This direct templating from leaves or other biological templates provides a straightforward means of replicating surface topography, enabling the precise copy of micro- and nanotextures of superhydrophobic surfaces found in nature. The key advantage of fabricated superhydrophobic surfaces in this thesis is their mechanical durability, which addresses a common vulnerability of fragile micro- and nanostructures. To overcome these challenges and improve mechanical robustness, this thesis explores various strategies, including creating overhanging structures, shielding nanostructures with microstructures, and applying hard coatings. We demonstrate the successful fabrication of durable superhydrophobic surfaces without the use of fluorine-based compounds. Our approach emphasizes that avoiding thin coatings is crucial for maintaining the robustness of these surfaces. Superhydrophobic materials and surfaces offer multifunctional benefits, including enhanced antibacterial effects and reduced ice adhesion. Their nanostructured design minimizes the solid contact area, hindering bacterial adhesion and growth by maintaining a trapped air layer between the surface and bacteria. We show that combining superhydrophobicity with copper significantly improves antibacterial properties compared to superhydrophobic-only surfaces and copper-only surfaces, as indicated by a notable decrease in the number of viable cells. Additionally, superhydrophobic surfaces exhibit remarkably low ice adhesion, especially in low-humidity conditions during freezing. The air pockets under water droplets slow heat transfer, delay ice formation, and further contribute to their multifunctionality. However, the micro- and nanostructures may sustain damage through repeated freezing and de-icing cycles. Our surfaces exhibit low ice adhesion after a number of icing–shearing cycles; however, after repeated freeze-thaw cycles, some degradation in their properties remained. Overall, the work demonstrates that superhydrophobic properties can be integrated into multifunctional surfaces, enabling them to function in practical applications.