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norskInstitutt for fysikk og teknologi: Nye registreringer
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Learning nanoscale motion patterns of vesicles in living cells
(Chapter; Bokkapittel, 2020)Detecting and analyzing nanoscale motion patterns of vesicles, smaller than the microscope resolution (~250 nm), inside living biological cells is a challenging problem. State-of-the-art CV approaches based on detection, tracking, optical flow or deep learning perform poorly for this problem. We propose an integrative approach, built upon physics based simulations, nanoscopy algorithms, and shallow ... -
A Kernel to Exploit Informative Missingness in Multivariate Time Series from EHRs
(Chapter; Bokkapittel, 2020)A large fraction of the electronic health records (EHRs) consists of clinical measurements collected over time, such as lab tests and vital signs, which provide important information about a patient’s health status. These sequences of clinical measurements are naturally represented as time series, characterized by multiple variables and large amounts of missing data, which complicate the analysis. ... -
A Protocol for Single-Molecule Translation Imaging in Xenopus Retinal Ganglion Cells
(Chapter; Bokkapittel, 2020-04-29)Single-molecule translation imaging (SMTI) is a straightforward technique for the direct quantification of local protein synthesis. The protein of interest is fused to a fast-folding and fast-bleaching fluorescent protein, allowing one to monitor the appearance of individual fluorescence events after photobleaching of pre-existing proteins in the cell under investigation. The translation of individual ... -
Unsupervised Band Selection for Hyperspectral Datasets by Double Graph Laplacian Diagonalization
(Journal article; Tidsskriftartikkel, 2021)The vast amount of spectral information provided by hyperspectral images can be useful for different applications. However, the presence of redundant bands will negatively affect application performance. Therefore, it is crucial to select a relevant subset that preserves the information of the original set. In this paper, we present an automatic and accurate band selection method based on Graph ... -
Explaining doping in material research (Hf substitution in ZnO films) by directly quantifying the van der Waals force
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-04)Non-monotonic behavior has been observed in the optoelectronic properties of ZnO thin films as doped with Hf (HZO). Here we propose that two competing mechanisms are responsible for such behaviour. Specifically, we propose that provided two crystal orientations dominate film growth, only one of them might be responsible for direct Hf substitution. Nonmonotonic behaviour is expected at once by ... -
Structured illumination microscopy using a photonic chip
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-11)Structured illumination microscopy (SIM) enables live-cell super-resolution imaging of subcellular structures at high speeds. At present, linear SIM uses free-space optics to illuminate the sample with the desired light patterns; however, such arrangements are prone to misalignment and add cost and complexity to the microscope. Here, we present an alternative photonic chip-based two-dimensional SIM ... -
Alignment of Multifrequency SAR Images Acquired over Sea Ice Using Drift Compensation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-07)In this article, we investigate the feasibility to align synthetic aperture radar (SAR) imagery based on a compensation for sea ice drift occurring between temporally shifted image acquisitions. The image alignment is a requirement for improving sea ice classification by combining multifrequency SAR images acquired at different times. Images obtained at different radar frequencies provide ... -
Effect of caffeine and other xanthines on liver sinusoidal endothelial cell ultrastructure
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-17)Xanthines such as caffeine and theobromine are among the most consumed psychoactive stimulants in the world, either as natural components of cofee, tea and chocolate, or as added ingredients. The present study assessed if xanthines affect liver sinusoidal endothelial cells (LSEC). Cultured primary rat LSEC were challenged with xanthines at concentrations typically obtained from normal consumption of ... -
Impacts of offshore oil spill accidents on island bird communities: A test run study around Orkney and Svalbard archipelagos
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-15)The sea area around the Orkney archipelago, Scotland is subjected to substantial maritime shipping activities. By contract, the Svalbard archipelago, Norway currently has a rather low marine traffic profile. Future projections, however, indicate that the Trans-Arctic route might change the whole transportation picture and Svalbard may be at the centre of maritime activities. Both archipelagos ... -
Outlier classification using Autoencoders: applications for fluctuation driven flows in fusion plasmas
(Conference object; Konferansebidrag, 2018) -
On confinement and plasma acceleration from a small ECR plasma source
(Conference object; Konferansebidrag, 2019)<p>Electron Cyclotron Resonance (ECR) is a technique to create high density, low temperature plasmas that do not depend on a cathode, like arc discharges and are therefore easier to maintain and have a longer lifespan. The use of the Electron Cyclotron Resonance (ECR) for electron heating for Magnetic Nozzle (MN) thrusters have recently received increased interest, as they have been shown to provide ... -
Should humans work?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-01)Should humans work? A simple question at a time when the advent of AI, automation and robotics claims a privileged position in the future of work. The question is perplexing and confusing however once we enquire into the meaning of technology and work as such: some claim that human jobs and well-being might be threatened by technological advances while others predict an increase in high skilled ... -
Solar energy for residential electric vehicle charging in Northern Norway – a feasibility study
(Conference object; Konferansebidrag, 2018)This paper presents a study of the potential for using photovoltaic (PV) solar energy systems for residential charging of electric vehicles (EVs) in Northern Norway. The objective is to investigate the load match between PV yield and uncontrolled EV charging, in terms of self-consumption and self-sufficiency. The load profile for EV charging is retrieved from a study by the Norwegian Water Resources ... -
Observation of mesospheric dust and ionospheric conditions during the G-chaser rocket campaign
(Conference object; Konferansebidrag, 2019)SPID, Smoke Particle Impact Detector, is a Faraday cup detector designed to measure nanometer-sized meteoric smoke particles during rocket flights. We report measurements made with SPID during the G-Chaser student rocket campaign 13 January 2019 and describe the design of the SPID instruments. Model calculations of dust trajectories within the detector result in an effective cross section of 0.97 ... -
Integrating incidence-angle compensation in the segmentation of UAVSAR images
(Conference object; Konferansebidrag, 2018)<p>SAR images display a characteristic intensity variation along the range dimension, caused by the fact that the backscattered intensities depend on the incidence angle. In the case of wide-swath images, this intensity variation from near range to far range is significant enough to affect image segmentation performed on absolute intensity values. The effects are an over-segmentation which creates ... -
Arctic Field Summer Schools: training the next generation of Arctic researchers
(Conference object; Konferansebidrag, 2018)<p>The Arctic Field Summer Schools project is funded by the Research Council of Norway (NFR) and Norwegian Centre for International Cooperation in Education (SIU), under the grant agreement number 261786/H30. <p>The project supports research and education collaboration among UiT - The Arctic University of Norway, University of Alaska Fairbanks (UAF), USA and University of Calgary (UC), Canada. <p>Through ... -
Modeling Microwave Scattering From Rough Sea Ice Surfaces
(Conference object; Konferansebidrag, 2017)In this paper, COMSOL Multiphysics® was used to simulate the microwave scattering from the rough sea ice surface. A nonperiodic model and a periodic model were built. The nonperiodic model considers the rough surface of finite length and introduces a tapered incident wave. In this model, the strategy of total and scattered-field decomposition (TSFD) was used to formulate the finite-element method ... -
Label-free imaging on waveguide platform with enhanced resolution and contrast
(Conference object; Konferansebidrag, 2021)Chip-based Evanescent Light Scattering (cELS) utilizes the multiple modes of a high-index contrast optical waveguide for near-field illumination of unlabeled samples, thereby repositioning the highest spatial frequencies of the sample into the far-field. The multiple modes scattering off the sample with different phase differences is engineered to have random spatial distributions within the integration ... -
Faszination Nano-Staubteilchen im Kosmos - Astronomie als Puzzle
(Conference object; Konferansebidrag, 2018) -
Radar studies of ionospheric dust - plasma phenomena
(Conference object; Konferansebidrag, 2018)Dust plasma phenomena occur in the Earth ionosphere in particular in the meteor ablation zone at altitudes ~50-95 km and above where radar meteors form. Radar also detect coherent polar mesospheric radar echoes (PME), i.e. radar echoes that are caused by spatial variations in the plasma refractive index at around 80 to 90 km altitude in the Earth’s mesosphere. During summer, PM(S)E form in the ...
