Doktorgradsavhandlinger (NT-fak): Recent submissions
Now showing items 21-40 of 305
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Toward a Collaborative Platform for Hybrid Designs Sharing a Common Cohort
(Doctoral thesis; Doktorgradsavhandling, 2024-01-18)<p>This doctoral thesis binds together four included papers in a thematical whole and is simultaneously an independent work proposing a platform facilitating epidemiological research. <p><i>Population-based prospective cohort studies</i> typically recruit a relatively large group of participants representative of a studied population and follow them over years or decades. This group of participants ... -
Multiple Signal Classification Algorithm: A computational microscopy tool for fluorescence microscopy
(Doctoral thesis; Doktorgradsavhandling, 2023-12-11)Fluorescence Microscopy is still the most preferred tool for studying the cell's inner structures. One of the reasons for this preference is its great selectivity, which allows it to label specific types of structures and visualize them with high contrast. However, its resolution is conventionally limited due to the diffraction of light, which makes the study of cells at scales below 200 nm challenging. ... -
Raman-spectroscopy of extracellular vesicles and self-supervised deep learning
(Doctoral thesis; Doktorgradsavhandling, 2023-12-07)This thesis explores the prospect of a waveguide device for optical trapping and Raman spectroscopy of single biological nanoparticles. The aim of the work is to develop a Raman-on-chip device capable of training and measuring single particles in individual trapping sites, such that the throughput of the device can be increased through parallelization. The challenge posed by the induced Raman ... -
Super-resolution histology
(Doctoral thesis; Doktorgradsavhandling, 2023-12-05)<p>Super-resolution optical microscopy (SRM) holds great promise for the advancement of life sciences, unlocking the secrets of the minute machinery composing living organisms. While broadly accepted in cell biology, the existing SRM methods haven’t effectively breached relevant fields such as histological practice, mainly due to the complexity, elevated costs, limited throughput, and incompatibility ... -
Planktonic foraminifers and shelled pteropods in the Barents Sea: Seasonal distribution and contribution to the carbon pump of the living fauna, and foraminiferal development during the last three millennia
(Doctoral thesis; Doktorgradsavhandling, 2023-12-06)The Arctic Ocean in general and the Barents Sea specifically, are highly affected by the human induced carbon dioxide (CO2) emissions and increasing temperatures. Atlantification, caused by an increase in warm Atlantic Water inflow, and polar amplification, caused by a higher impact of the increasing temperatures at high latitudes, have already been observed. Moreover, the Barents Sea has been ... -
Mesospheric Dust - radar applications for detection and investigation
(Doctoral thesis; Doktorgradsavhandling, 2023-11-15)<p>Large amounts of meteoric particles ablate globally into the Earth’s atmosphere each day, and they interact with the atmosphere through several processes in the mesosphere and below. These processes include dust charging, where dust is expected to influence the charge balance in the D-region of the ionosphere. Consequently, the charged dust particles can influence the incoherent scatter that is ... -
On the time-dependence of climate sensitivity
(Doctoral thesis; Doktorgradsavhandling, 2023-11-03)Climate sensitivity is the change of the global-mean surface temperature in response to a doubling of the CO2 concentration. It is typically used to describe climate change and to inform decision-making for mitigation and adaptation. Climate sensitivity is often estimated in numerical climate model experiments. A remarkable result from these experiments is that climate sensitivity changes over time. ... -
Radar studies of plasma parameters in the polar cap and the auroral zone
(Doctoral thesis; Doktorgradsavhandling, 2018-04-11)Incoherent scatter radar measurements are an important source for studies of ionospheric plasma parameters. Data from the EISCAT Svalbard radar (ESR), which covers the polar cap and cusp, and from the EISCAT Tromsø radars, which covers the auroral zone, can be used to obtain information about the electron density, electron- and ion temperature, and line-of-sight plasma velocity. As the ESR started ... -
Enhancing Decision-making in the Electric Power Sector with Machine Learning and Optimization
(Doctoral thesis; Doktorgradsavhandling, 2023-10-23)<p>The electric power system infrastructure is essential for modern economies and societies, as it provides the electricity needed to power homes, businesses, and industries. It is of critical importance that the operation of the electric power system is optimized to serve the electricity demand reliably and sustainably. Advances in machine learning and optimization have enabled the potential to ... -
Deep convolutional regression modelling for forest parameter retrieval
(Doctoral thesis; Doktorgradsavhandling, 2023-10-06)<p>Accurate forest monitoring is crucial as forests are major global carbon sinks. Additionally, accurate prediction of forest parameters, such as forest biomass and stem volume (SV), has economic importance. Therefore, the development of regression models for forest parameter retrieval is essential. <p>Existing forest parameter estimation methods use regression models that establish pixel-wise ... -
Intermittent fluctuations in the boundary of magnetically confined fusion plasmas
(Doctoral thesis; Doktorgradsavhandling, 2023-10-09)Fluctuation-induced transport in the form of hot and dense blob-like filaments is a profound concern for the successful operation of commercially-viable fusion reactors. These turbulent phenomena are inherent in the scrape-off layer (SOL), a region of magnetic field lines intersecting with the material surfaces. These filaments propagate radially outward leading to damaging plasma-wall interaction ... -
Predictive Modeling for Fair and Efficient Transaction Inclusion in Proof-of-Work Blockchain Systems
(Doctoral thesis; Doktorgradsavhandling, 2023-10-02)This dissertation investigates the strategic integration of Proof-of-Work(PoW)-based blockchains and ML models to improve transaction inclusion, and consequently molding transaction fees, for clients using cryptocurrencies such as Bitcoin. The research begins with an in-depth exploration of the Bitcoin fee market, focusing on the interdependence between users and miners, and the emergence of a fee ... -
Methods for enhanced learning using wearable technologies. A study of the maritime sector
(Doctoral thesis; Doktorgradsavhandling, 2023-10-04)Maritime safety is a critical concern due to the potential for serious consequences or accidents for the crew, passengers, environment, and assets resulting from navigation errors or unsafe acts. Traditional training methods face challenges in the rapidly evolving maritime industry, and innovative training methods are being explored. This study explores the use of wearable sensors with biosignal ... -
Seismicity of the western-Svalbard margin and its relationship with near surface fluid flow and seepage systems - A study using ocean bottom seismometers
(Doctoral thesis; Doktorgradsavhandling, 2023-09-28)Methane, a high potential greenhouse gas, travels as a fluid and releases as a gas in large quantities from the seafloor. This seepage impacts marine ecosystems and in specific cases, it has potential to reach the atmosphere, and therefore affect the climate. Gas seepage is documented worldwide, but there are still large unknowns regarding seepage dynamics, faulting/fracturing of the sediments and ... -
Dielectric nanoantennas and metasurfaces for optical trapping
(Doctoral thesis; Doktorgradsavhandling, 2023-09-14)Analysis of biological nanoparticles in medical sciences is very promising, as it can reveal groundbreaking information about disease mechanisms, potentially leading to innovative and more effective treatment strategies. The existing methods used for analyzing biological nanoparticles come with several limitations, involving extensive sample preparation, and giving limited information about the ... -
Improving Representation Learning for Deep Clustering and Few-shot Learning
(Doctoral thesis; Doktorgradsavhandling, 2023-08-23)<p>The amounts of data in the world have increased dramatically in recent years, and it is quickly becoming infeasible for humans to label all these data. It is therefore crucial that modern machine learning systems can operate with few or no labels. The introduction of deep learning and deep neural networks has led to impressive advancements in several areas of machine learning. These advancements ... -
Dutkat: A Privacy-Preserving System for Automatic Catch Documentation and Illegal Activity Detection in the Fishing Industry
(Doctoral thesis; Doktorgradsavhandling, 2023-08-17)United Nations' Sustainable Development Goal 14 aims to conserve and sustainably use the oceans and their resources for the benefit of people and the planet. This includes protecting marine ecosystems, preventing pollution, and overfishing, and increasing scientific understanding of the oceans. Achieving this goal will help ensure the health and well-being of marine life and the millions of people ... -
Exploring multipartite genomes using pangenome analysis
(Doctoral thesis; Doktorgradsavhandling, 2023-06-21)<p>Bacteria are small single-celled organisms that are found in nearly every habitat on Earth. While bacterial genomes usually consist of one large circular replicon, about 10% of bacteria have organized their genes onto several large replicons. These multipartite bacteria are often found in symbiotic or pathogenic relationships with other higher organisms and are believed to have greater ability ... -
Multimodal Integrated Remote Sensing for Arctic Sea Ice Monitoring
(Doctoral thesis; Doktorgradsavhandling, 2023-06-15)Remote sensing data acquired from various sensors have been used for decades to monitor sea ice conditions over polar regions. Sea ice plays an essential role in the polar environment and climate. Furthermore, sea ice affects anthropogenic activities, including shipping and navigation, the oil and gas industry, fisheries, tourism, and the lifestyle of the indigenous population of the Arctic. With ... -
Advancing Deep Learning for Marine Environment Monitoring
(Doctoral thesis; Doktorgradsavhandling, 2023-06-09)Marine environment monitoring has become increasingly significant due to the excessive exploitation of oceans, which detrimentally impacts ecosystems. Deep learning provides an effective monitoring approach by automating the analysis of vast amounts of observed image data, enabling stakeholders to make informed decisions regarding fishing quotas or conservation efforts. The success of deep learning ...