Fakultet for naturvitenskap og teknologi: Nye registreringer
Viser treff 2201-2220 av 5379
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A Study of Electrical Load Forecasting by Synergetic Time Series Clustering in a Temporal Convolutional Network
(Master thesis; Mastergradsoppgave, 2021-06-15)In this thesis time series forecasting is reviewed and performed on electrical load time series. The main dataset that is used consists of 4074 load time series, each collected from a secondary substation. The time series in this set cover hourly observations spanning more than 2 years, and these time series all have different patterns, some being more similar to each other. We explore how we ... -
Analysis of Correlations between Energy Consumption, Structural Specifications and Climate-Induced Variables to increase Energy Efficiency in Households and Buildings through a Prediction Model
(Master thesis; Mastergradsoppgave, 2021-05-31)In a world where the transition towards increasingly progressive renewable energy sources is of great importance moving towards sustainability for our planet and future generations, a large portion of mundane equipment and machinery will turn to the usage of electricity rather than fossil fuel as a resource. This does however pose some challenges to the infrastructure in place as it increases the ... -
Cometary plasma science: Open science questions for future space missions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-07)Comets hold the key to the understanding of our Solar System, its formation and its evolution, and to the fundamental plasma processes at work both in it and beyond it. A comet nucleus emits gas as it is heated by the sunlight. The gas forms the coma, where it is ionised, becomes a plasma, and eventually interacts with the solar wind. Besides these neutral and ionised gases, the coma also contains ... -
Crystal rotations and alignment in spatially varying magma flows: 2-D examples of common subvolcanic flow geometries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-31)Elongate inclusions immersed in a viscous fluid generally rotate at a rate that is different from the local angular velocity of the flow. Often, a net alignment of the inclusions develops, and the resulting shape preferred orientation of the particle ensemble can then be used as a strain marker that allows reconstruction of the fluid’s velocity field. Much of the previous work on the dynamics of ... -
Enhanced Arctic stratification in a warming scenario: Evidence from the mid pliocene warm Pperiod
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-10)Global warming is most pronounced in the Arctic as evident from the massive sea ice loss during the past few decades. The Mid-Pliocene Warm Period (MPWP), 3.264 – 3.025 million years ago with similar CO2 levels, is the nearest analogue for understanding the impacts of future global warming. High-resolution studies of relative nutrient utilization and productivity from the Atlantic-Arctic Gateway ... -
Accident Prediction Model Using Machine Learning. Accuracy of Predicted Model
(Master thesis; Mastergradsoppgave, 2021-06-22)Logistic regression is a predictive model machine learning algorithm that displays the results in a binary form, mostly used in prediction multivariable and as an advanced version of linear regression, here we used to predict the accuracy of our model. Current accident prediction model in Norway is Tusi is a risk based model used in predicting tunnel accidents but it has some problems and loose ends ... -
Symmetric ideals, Specht polynomials and solutions to symmetric systems of equations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-18)An ideal of polynomials is symmetric if it is closed under permutations of variables. We relate general symmetric ideals to the so called Specht ideals generated by all Specht polynomials of a given shape. We show a connection between the leading monomials of polynomials in the ideal and the Specht polynomials contained in the ideal. This provides applications in several contexts. Most notably, this ... -
Electron Bulk Heating at Saturn’s Magnetopause
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-25)Magnetic reconnection at the magnetopause (MP) energizes ambient plasma via the release of magnetic energy and produces an “open” magnetosphere allowing solar wind particles to directly enter the system. At Saturn, the nature of MP reconnection remains unclear. The current study examines electron bulk heating at MP crossings, in order to probe the relationship between observed and predicted reconnection ... -
Provenance, depositional setting and diagenesis as keys to reservoir quality of the Lower Cretaceous in the SW Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-06)This study examines the role of the depositional environment for the final reservoir quality in four Lower Cretaceous sandstone reservoirs in the southwestern Barents Sea by linking facies to the distribution of primary textures, composition, and diagenetic alteration. Facies analysis reveals slope-to-basin-floor, distal shallow-marine, and deltaic depositional environments. The slope-to-basin-floor ... -
Instance Segmentation of Microscopic Foraminifera
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-16)Foraminifera are single-celled marine organisms that construct shells that remain as fossils in the marine sediments. Classifying and counting these fossils are important in paleo-oceanographic and -climatological research. However, the identification and counting process has been performed manually since the 1800s and is laborious and time-consuming. In this work, we present a deep learning-based ... -
Engaging Social Media Users with Health Education and Physical Activity Promotion
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021)Health-dedicated groups on social media provide different contents and social support to their peers. Our objective is to analyze users’ engagement with health education and physical activity promotion posts according to the expressed social support and social media. All health education and physical activity promotion posts on Facebook, Twitter, and Instagram during 2017–2019 by a diabetes association ... -
Luminescence dating of holocene siliciclastic sediments in eastern Dahomey Basin, southwestern Nigeria
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-02)Several attempts at reconstructing geological settings and palaeoclimatic changes of the siliciclastic deposits of the Dahomey Basin, SW Nigeria, using relative age dating and correlation methods, have resulted in serious discrepancies on the ages. Therefore, a chronology framework established by an absolute age dating method is requisite to constrain the geological interpretation. This research ... -
Palaeoproterozoic foreland fold-thrust belt structures and lateral faults in the West Troms Basement Complex, northern Norway, and their relation to inverted metasedimentary sequences
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-15)Palaeoproterozoic fold-thrust belt structures and steep, lateral shear zones characterize the foreland deformation of Neoarchaean basement tonalites in Vanna, West Troms Basement Complex, northern Norway. Low-grade par-autochthonous and allochthonous cover units (2.4–2.2. Ga) with sandstones and calcareous metapelites exist in separate areas of the foreland. They were formed as intracontinental rift- ... -
Historical contingency impacts on community assembly and ecosystem function in chemosynthetic marine ecosystems
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-07)Predicting ecosystem functioning requires an understanding of the mechanisms that drive microbial community assembly. Many studies have explored microbial diversity extensively and environmental factors are thought to be the principal drivers of community composition. Community assembly is, however, also influenced by past conditions that might affect present-day assemblages. Historical events, ... -
Deep ocean storage of heat and CO2 in the Fram Strait, Arctic Ocean during the last glacial period
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-19)The Fram Strait is the only deep gateway between the Arctic Ocean and the Nordic Seas and thus is a key area to study past changes in ocean circulation and the marine carbon cycle. Here, we study deep ocean temperature, δ18O, carbonate chemistry (i.e., carbonate ion concentration [CO32−]), and nutrient content in the Fram Strait during the late glacial (35,000–19,000 years BP) and the Holocene based ... -
Classification of Simply-Transitive Levi Non-Degenerate Hypersurfaces in C^3
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-24)Holomorphically homogeneous Cauchy–Riemann (CR) real hypersurfaces M<sup>3</sup>⊂C<sup>2</sup> were classified by Élie Cartan in 1932. In the next dimension, we complete the classification of simply-transitive Levi non-degenerate hypersurfaces M<sup>5</sup>⊂C<sup>3</sup> using a novel Lie algebraic approach independent of any earlier classifications of abstract Lie algebras. Central to our approach ... -
On the Evolvability of OXA-48. A comprehensive study of new functions within the β-lactamase OXA-48
(Doctoral thesis; Doktorgradsavhandling, 2021-08-27)Our understanding of how antimicrobial resistance enzymes evolve to expand their substrate spectrum is limited. OXA-48, an enzyme able to catalyse the hydrolysis of β-lactam drugs, has become one of the most successfully disseminating β-lactamases. Although OXA-48 hydrolyses penicillins with high efficiency, its activity towards oxyimino cephalosporins, such as ceftazidime, is limited. Thus, ceftazidime ... -
Why Is the Construction Industry Killing More Workers Than the Offshore Petroleum Industry in Occupational Accidents?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-07)In Norway, the fatal accident frequency per year is discernibly higher in the construction industry than in the petroleum industry. To probe the difference between the occupational safety levels in the two industries in Norway, semi-structured interviews with regulators, employer and employee organisations, company management, and safety personnel were conducted. This qualitative approach, together ... -
Highly efficient and scalable framework for high-speed super-resolution microscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-05)The multiple signal classification algorithm (MUSICAL) is a statistical super-resolution technique for wide-field fluorescence microscopy. Although MUSICAL has several advantages, such as its high resolution, its low computational performance has limited its exploitation. This paper aims to analyze the performance and scalability of MUSICAL for improving its low computational performance. We first ... -
Behavioural change in green transportation: Micro-economics perspectives and optimization strategies
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-22)The increasing demand for Electric Vehicle (EV) charging is putting pressure on the power grids and capacities of charging stations. This work focuses on how to use indirect control through price signals to level out the load curve in order to avoid the power consumption from exceeding these capacities. We propose mathematical programming models for the indirect control of EV charging that aim at ...