Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 2981-3000 of 5336
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Time Series Kernel Similarities for Predicting Paroxysmal Atrial Fibrillation from ECGs
(Journal article; Tidsskriftartikkel, 2018)We tackle the problem of classifying Electrocardiography (ECG) signals with the aim of predicting the onset of Paroxysmal Atrial Fibrillation (PAF). Atrial fibrillation is the most common type of arrhythmia, but in many cases PAF episodes are asymptomatic. Therefore, in order to help diagnosing PAF, it is important to design procedures for detecting and, more importantly, predicting PAF episodes. ... -
Changes in sea ice cover and ice sheet extent at the Yermak Plateau during the last 160 ka - Reconstructions from biomarker records
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-15)The Yermak Plateau is located north of Svalbard at the entrance to the Arctic Ocean, i.e. in an area highly sensitive to climate change. A multi proxy approach was carried out on Core PS92/039-2 to study glacial-interglacial environmental changes at the northern Barents Sea margin during the last 160 ka. The main emphasis was on the reconstruction of sea ice cover, based on the sea ice proxy ... -
The deep kernelized autoencoder
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-18)Autoencoders learn data representations (codes) in such a way that the input is reproduced at the output of the network. However, it is not always clear what kind of properties of the input data need to be captured by the codes. Kernel machines have experienced great success by operating via inner-products in a theoretically well-defined reproducing kernel Hilbert space, hence capturing topological ... -
Results from the intercalibration of optical low-light calibration sources 2011
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012-05-03)Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to the ... -
Urban land cover classification with missing data modalities using deep convolutional neural networks
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-14)Automatic urban land cover classification is a fundamental problem in remote sensing, e.g., for environmental monitoring. The problem is highly challenging, as classes generally have high interclass and low intraclass variances. Techniques to improve urban land cover classification performance in remote sensing include fusion of data from different sensors with different data modalities. However, ... -
A new method of inferring the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-15)<p>We present a new method of analyzing measurements of mesospheric dust made with DUSTY rocket-borne Faraday cup probes. It can yield the variation in fundamental dust parameters through a mesospheric cloud with an altitude resolution down to 10 cm or less if plasma probes give the plasma density variations with similar height resolution. A DUSTY probe was the first probe that unambiguously detected ... -
Weather situation during observed ship-icing events off the coast of Northern Norway and the Svalbard archipelago
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-19)Ship icing may lead the ship and crew in great jeopardy. Usually, predictions of such ice build-up are based on the modelling of the heat fluxes capable of freezing sea water originated from wave-ship interactions. This study, on the other hand, follows a different and more general approach by investigating the relationship between the weather situation and icing both using observed parameters from ... -
Impact of assimilating sea ice concentration, sea ice thickness and snow depth in a coupled ocean-sea ice modelling system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-08)The accuracy of the initial state is very important for the quality of a forecast, and data assimilation is crucial for obtaining the best-possible initial state. For many years, sea-ice concentration was the only parameter used for assimilation into numerical sea-ice models. Sea-ice concentration can easily be observed by satellites, and satellite observations provide a full Arctic coverage. During ... -
Catalytic Intermolecular Functionalization of Benzimidazoles
(Peer reviewed; Chapter; Bokkapittel, 2019-06-25)This chapter describes contemporary strategies for selective catalytic intermolecular functionalization of the benzimidazole scaffold. Functionalization at nitrogen and position C-2 is well developed employing copper, palladium, rhodium, nickel, and cobalt catalysis. Direct CH activation is the predominant approach to C-2 functionalization. Nickel-based catalysts can activate C—O bonds in conjunction ... -
Closely-related Photobacterium strains comprise the majority of bacteria in the gut of migrating Atlantic cod (Gadus morhua)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-17)<p><i>Background - </i>The population of Atlantic cod (<i>Gadus morhua</i>), also known as Northeast Arctic cod, migrating Atlantic cod, or simply “skrei,” lives mainly in the Barents Sea and Svalbard waters and migrates in annual cycles to the Norwegian coast in order to spawn eggs during late winter. It is the world’s largest population of Atlantic cod, and the population is distinct from the ... -
SKIM, a Candidate Satellite Mission Exploring Global Ocean Currents and Waves
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-30)The Sea surface KInematics Multiscale monitoring (SKIM) satellite mission is designed to explore ocean surface current and waves. This includes tropical currents, notably the poorly known patterns of divergence and their impact on the ocean heat budget, and monitoring of the emerging Arctic up to 82.5°N. SKIM will also make unprecedented direct measurements of strong currents, from boundary currents ... -
Data-driven blood glucose pattern classification and anomalies detection: Machine-learning applications in Type 1 diabetes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-01)<p><i>Background - </i>Diabetes mellitus is a chronic metabolic disorder that results in abnormal blood glucose (BG) regulations. The BG level is preferably maintained close to normality through self-management practices, which involves actively tracking BG levels and taking proper actions including adjusting diet and insulin medications. BG anomalies could be defined as any undesirable reading ... -
Modeling Energy Consumption of Computing Systems: from Homogeneous to Heterogeneous Systems
(Doctoral thesis; Doktorgradsavhandling, 2019-09-06)Nowadays, reducing energy consumption and improving the energy efficiency of computing systems become ones of the leading research topics in computer science. In order to improve energy efficiency, it is crucial to understand how computing systems consume energy. Power and energy models provide prediction and insight into how computing systems consume power and energy. However, it is challenging to ... -
Deep Reinforcement Learning for Query-Conditioned Video Summarization
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-21)Query-conditioned video summarization requires to (1) find a diverse set of video shots/frames that are representative for the whole video, and that (2) the selected shots/frames are related to a given query. Thus it can be tailored to different user interests leading to a better personalized summary and differs from the generic video summarization which only focuses on video content. Our work targets ... -
CPPE: An Open-Source C++ and Python Library for Polarizable Embedding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-03)We present a modular open-source library for polarizable embedding (PE) named CPPE. The library is implemented in C++, and it additionally provides a Python interface for rapid prototyping and experimentation in a high-level scripting language. Our library integrates seamlessly with existing quantum chemical program packages through an intuitive and minimal interface. Until now, CPPE has been ... -
Reproduction study using public data of: Development and validation of a deep learning algorithm for detection of diabetic retinopathy in retinal fundus photographs
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-06)We have attempted to reproduce the results in <i>Development and validation of a deep learning algorithm for detection of diabetic retinopathy in retinal fundus photographs</i>, published in JAMA 2016; 316(22), using publicly available data sets. We re-implemented the main method in the original study since the source code is not available. The original study used non-public fundus images from EyePACS ... -
Recommendations with a Nudge
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-13)In areas such as health, environment, and energy consumption, there is a need to do better. A common goal in society is to get people to behave in ways that are sustainable for the environment or support a healthier lifestyle. Nudging is a term known from economics and political theory, for influencing decisions and behavior using suggestions, positive reinforcement, and other non-coercive means. ... -
Convolutional Neural Network for Breathing Phase Detection in Lung Sounds
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-15)We applied deep learning to create an algorithm for breathing phase detection in lung sound recordings, and we compared the breathing phases detected by the algorithm and manually annotated by two experienced lung sound researchers. Our algorithm uses a convolutional neural network with spectrograms as the features, removing the need to specify features explicitly. We trained and evaluated the ... -
Sparse signal recovery in MIMO specular meteor radars with waveform diversity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-15)Since the 1950s, specular meteor radars (SMRs) have been used to study the mesosphere and lower thermosphere (MLT) dynamics. Atmospheric parameters derived from SMRs are highly dependent on the number of detected meteors and the accuracy of the meteors' locations. Recently, incoherent and coherent multiple-input-multiple-output (MIMO) radar approaches combined with waveform diversity have been ... -
Investigation of exceptionally radar-dark regions on the lunar nearside
(Conference object; Konferansebidrag, 2019-08)Remote sensing of planetary surfaces is an effective method for gaining knowledge of the processes that shape the planetary bodies in our solar system. This is useful for uncovering the environment of the primordial solar system and to study the current state of the upper crusts of the other planets in our neighborhood. A recent 6-meter wavelength polarimetric radar map of the Moon [?] showed ...