Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 3301-3320 of 5336
-
An improved spatial and temporal reflectance unmixing model to synthesize time series of landsat-like images
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-31)The trade-off between spatial and temporal resolution limits the acquisition of dense time series of Landsat images, and limits the ability to properly monitor land surface dynamics in time. Spatiotemporal image fusion methods provide a cost-efficient alternative to generate dense time series of Landsat-like images for applications that require both high spatial and temporal resolution images. The ... -
Quantitative phase microscopy of red blood cells during planar trapping and propulsion
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-22)Red blood cells (RBCs) have the ability to undergo morphological deformations during microcirculation, such as changes in surface area, volume and sphericity. Optical waveguide trapping is suitable for trapping, propelling and deforming large cell populations along the length of the waveguide. Bright field microscopy employed with waveguide trapping does not provide quantitative information about ... -
Performance principles for trusted computing with intel SGX
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-14)Cloud providers offering Software-as-a-Service (SaaS) are increasingly being trusted by customers to store sensitive data. Companies often monetize such personal data through curation and analysis, providing customers with personalized application experiences and targeted advertisements. Personal data is often accompanied by strict privacy and security policies, requiring data processing to be ... -
SuperDARN radar-derived HF radio attenuation during the September 2017 solar proton events
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-10)Two solar proton events in September 2017 had a significant impact on the operation of the Super Dual Auroral Radar Network (SuperDARN), a global network of high‐frequency (HF) radars designed for observing F region ionospheric plasma convection. Strong polar cap absorption caused near‐total loss of radar backscatter, which prevented the primary SuperDARN data products from being determined for a ... -
Small data: practical modeling issues in human-model -omic data
(Doctoral thesis; Doktorgradsavhandling, 2019-02-08)Human-model data are very valuable and important in biomedical research. Ethical and economical constraints limit the access to such data, and consequently these datasets rarely comprise more than a few hundred observations. As measurements are comparatively cheap, the tendency is to measure as many things as possible for the few, valuable participants in a study. With -omics technologies it is cheap ... -
Advancing Unsupervised and Weakly Supervised Learning with Emphasis on Data-Driven Healthcare
(Doctoral thesis; Doktorgradsavhandling, 2019-02-15)In healthcare, vast amounts of data are stored digitally in the electronic health records (EHRs). EHRs represent a largely untapped source of clinically relevant information, which combined with advances in machine learning, have the potential to transform healthcare into a more data-driven direction. However, due to the complexity and poor quality of the EHRs, data-driven healthcare is facing many ... -
PCMSolver: an Open-Source Library for Solvation Modeling
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-25)PCMSolver is an open‐source library for continuum electrostatic solvation. It can be combined with any quantum chemistry code and requires a minimal interface with the host program, greatly reducing programming effort. As input, PCMSolver needs only the molecular geometry to generate the cavity and the expectation value of the molecular electrostatic potential on the cavity surface. It then returns ... -
Deep learning and hand-crafted feature based approaches for polyp detection in medical videos
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-23)Video analysis including classification, segmentation or tagging is one of the most challenging but also interesting topics multimedia research currently try to tackle. This is often related to videos from surveillance cameras or social media. In the last years, also medical institutions produce more and more video and image content. Some areas of medical image analysis, like radiology or brain ... -
Dissecting deep neural networks for better medical image classification and classification understanding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-23)Neural networks, in the context of deep learning, show much promise in becoming an important tool with the purpose assisting medical doctors in disease detection during patient examinations. However, the current state of deep learning is something of a "black box", making it very difficult to understand what internal processes lead to a given result. This is not only true for non-technical users but ... -
Universality of Poisson-driven plasma fluctuations in the Alcator C-Mod scrape-off layer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-18)Large-amplitude, intermittent fluctuations are ubiquitous in the boundary region of magnetically confined plasmas and lead to detrimental plasma-wall interactions in the nextgeneration, high duty cycle fusion power experiments. Using gas puff imaging data time series from the scrape-off layer in the Alcator C-Mod device, it is here demonstrated that the large-amplitude fluctuations can be described ... -
Effect of Wind Direction and Incidence Angle on Polarimetric SAR Observations of Slicked and Unslicked Sea Surfaces
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-12)The objective of this paper is to investigate the dependency of oil spill observations in polarimetric SAR data on imaging geometry, i.e., on incidence angle and look direction relative to the wind. The study is based on quad-polarization data acquired by the Uninhabited Aerial Vehicle Synthetic Aperture Radar over experimental oil slicks under relatively high winds of 10–12 m/s over an 8-hour period. ... -
Measurement of Oil Slick Transport and Evolution in the Gulf of Mexico using L-band Synthetic Aperture Radar
(Journal article; Tidsskriftartikkel, 2018-06)The transport and evolution of a mineral oil slick originating at a seep in the Gulf of Mexico approximately 16 km offshore of the mouth of the Mississippi River is measured using a series of images acquired at 40 minute intervals with the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), an L-band, high resolution, high signal-to-noise instrument operated by the U.S. National Aeronautics ... -
Iceberg detection in open water and sea ice using C-band radar polarimetry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-04)Icebergs can cause a significant danger for shipping, offshore oil exploration, and undersea or subsea pipelines and production facilities. Synthetic aperture radar (SAR) is very valuable tool of detecting and monitoring icebergs in the often dark and cloud-covered polar regions. Detection of small icebergs floating in nonhomegeous sea clutter environments is a challenging task in remote sensing. ... -
Relating Photoelectrochemistry and Wettability of Sputtered Cu- and N-Doped TiO<sub>2</sub> Thin Films via an Integrated Approach
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-06)We present here an integrated study of the photoelectrochemical and hydrophilic properties of sputtered TiO<sub>2</sub> thin films, enhanced by means of nitrogen (N) and copper (Cu) doping. We investigated the effect that doping has on both photoelectrochemical efficiency and surface properties by employing a variety of techniques spanning from impedance electrochemical impedance spectroscopy to ... -
Toward Reproducible Analysis and Exploration of High-Throughput Biological Datasets
(Doctoral thesis; Doktorgradsavhandling, 2019-01-21)This dissertation argues that we can develop unified systems for reproducible exploration and analysis of high-throughput biological datasets. We propose an approach, Small Modular Entities (SME), that orchestrates the execution of analysis pipelines and data exploration applications. We realize SMEs using software container technologies together with well-defined interfaces, configuration, and ... -
The evolution in graphitic surface wettability with first-principles quantum simulations: the counterintuitive role of water
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-08)The surface wettability of graphite has gained a lot of interest in nanotechnology and fundamental studies alike, but the types of adsorptions that dominate its time resolved surface property variations in ambient environment are still elusive. Prediction of the intrinsic surface wettability of graphite from first-principles simulations offers an opportunity to clarify the overall evolution. In this ... -
Projectable Lie algebras of vector fields in 3D
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-15)Starting with Lie’s classification of finite-dimensional transitive Lie algebras of vector fields on <b>C<sup>2</sup></b> we construct transitive Lie algebras of vector fields on the bundle <b>C<sup>2</sup> x C</b> by lifting the Lie algebras from the base. There are essentially three types of transitive lifts and we compute all of them for the Lie algebras from Lie’s classification. The simplest ... -
Repeatability of high-resolution 3D seismic data
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-21)High-resolution 4D (HR4D) seismic data have the potential for improving the current state-of-the-art in detecting shallow (≤500−1000 m below seafloor) subsurface changes on a very fine scale (approximately 3–6 m). Time-lapse seismic investigations commonly use conventional broadband seismic data, considered low to moderate resolution in our context. We have developed the first comprehensive time ... -
Discerning the Contribution of Morphology and Chemistry in Wettability Studies
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-15)The wetting behavior of homogeneous systems is now well understood at the macroscopic scale. However, this understanding offers little predictive power regarding wettability when mesoscopic chemical and morphological heterogeneities come into play. The fundamental interest in the effect of heterogeneity on wettability is derived from its high technological relevance in several industries, including ... -
Arctic Sea Ice Characterization using Spaceborne Fully Polarimetric L-, C- and X-Band SAR with Validation by Airborne Measurements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-26)In recent years, spaceborne synthetic aperture radar (SAR) polarimetry has become a valuable tool for sea ice analysis. Here, we employ an automatic sea ice classification algorithm on two sets of spatially and temporally near coincident fully polarimetric acquisitions from the ALOS-2, Radarsat-2, and TerraSAR-X/TanDEM-X satellites. Overlapping coincident sea ice freeboard measurements from airborne ...