Viser treff 241-260 av 1325

    • Optical Remote Sensing of Oil Spills by using Machine Learning Methods in the Persian Gulf: A Multi-Class Approach 

      Evenseth, Martin H. (Master thesis; Mastergradsoppgave, 2023-06-15)
      Marine oil spills are harmful for the environment and costly for society. Coastal areas are particularly vulnerable since they provide habitats for organisms, animals and marine ecosystems. This thesis studied machine learning methods to classify thick oil in a multi-class case, using remotely sensed multi-spectral data in the Persian Gulf. The study area covers a large area between United Arab ...
    • Solenergi i mikronett ved gårdsbruk på Røros 

      Løchen, Eiliv Erik Ulrich (Master thesis; Mastergradsoppgave, 2023-06-01)
      I denne masteroppgaven har jeg undersøkt hvilket solenergisystem som vil være det mest hensiktsmessige for å minimere belastningen på det lokale strømnettet på Røros. Dette ble gjort ved å se på dimensjonering av solenergianlegg og batteripakker i et mikronett. Dette gjorde jeg ved å bruke solstrålingsdatabaser, og basert på dagens solcelle- og batteriteknologi, beregne hvor mye strøm som kan ...
    • Natural occuring oil seepages as a consequence of bottom trawling? 

      Hindenes, Sander (Mastergradsoppgave; Master thesis, 2023-05-31)
      Bottom trawling is used to capture fish species that live in the seabed. The damage on the seabed trawling causes has been discussed for many years. This thesis aims to investigate whether bottom trawling for sand eels can be a cause for some of the detected oil seepages in the North Sea. We investigated this using manual delineation of oil seepages in Synthetic Aperture Radar (SAR) satellite ...
    • Viewing life without labels under optical microscopes 

      Ghosh, Biswajoy; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-25)
      Optical microscopes today have pushed the limits of speed, quality, and observable space in biological specimens revolutionizing how we view life today. Further, specific labeling of samples for imaging has provided insight into how life functions. This enabled label-based microscopy to percolate and integrate into mainstream life science research. However, the use of labelfree microscopy has been ...
    • Deep generative models for reject inference in credit scoring 

      Andrade Mancisidor, Rogelio; Kampffmeyer, Michael; Aas, Kjersti; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-21)
      Credit scoring models based on accepted applications may be biased and their consequences can have a statistical and economic impact. Reject inference is the process of attempting to infer the creditworthiness status of the rejected applications. Inspired by the promising results of semi-supervised deep generative models, this research develops two novel Bayesian models for reject inference in credit ...
    • Learning latent representations of bank customers with the Variational Autoencoder 

      Andrade Mancisidor, Rogelio; Kampffmeyer, Michael; Aas, Kjersti; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-15)
      Learning data representations that reflect the customers’ creditworthiness can improve marketing campaigns, customer relationship management, data and process management or the credit risk assessment in retail banks. In this research, we show that it is possible to steer data representations in the latent space of the Variational Autoencoder (VAE) using a semi-supervised learning framework and a ...
    • Oceanographic variability and change in two fjords in northern Norway 

      Bjørndalen, Elena (Mastergradsoppgave; Master thesis, 2023-06-01)
      Long-term hydrographic time series data from two fixed stations in the northern Norwegian fjords Malangen and Balsfjorden from the period 1980 - 2022 have been examined. The data have been supplemented with model results from the ocean model NorFjords160 over the period April 1st 2017 to December 31st 2022. To gain a deeper understanding of the oceanographic variability and change, the environmental ...
    • Conditional averaging of overlapping pulses 

      Nilsen, Rolf Annar Berg (Mastergradsoppgave; Master thesis, 2023-05-15)
      Conditional averaging is a signal processing method used to study turbulent fluctuations in a variety of fields. The method, in its simplest form, works by finding peaks in a signal that fulfill a certain size threshold. Equally sized excerpts of the signal around every peak are then cut out and averaged. This yields the average shape of the events that fulfill the condition. Based on the peak ...
    • An investigation on the damping ratio of marine oil slicks in synthetic aperture radar imagery 

      Quigley, Cornelius Patrick; Johansson, Malin; Jones, Cathleen Elaine (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-12)
      The damping ratio has recently been used to indicate the relative internal oil thickness within oil slicks observed in synthetic aperture radar (SAR) imagery. However, there exists no well-defined and evaluated methodology for calculating the damping ratio. In this study, we review prior work regarding the damping ratio and outline its theoretical and practical aspects. We show that the most often ...
    • Towards automation in the fish processing industry using machine learning 

      Henriksen, Jostein (Master thesis; Mastergradsoppgave, 2023-04-11)
      This master project was inspired by challenges faced by commercial fisheries in the north of Norway of controlling food quality and food safety. In this thesis, four different ML models’ ability to do object and keypoint detection on specific anatomy parts of fish, has been studied. With the aim of recommending a suitable model to be part of a CV system for an industrial fish gutting machine that ...
    • A comparative study of lens-less and lens-based optical imaging using full electric field analysis 

      Sommernes, Jon-Richard (Mastergradsoppgave; Master thesis, 2021-05-13)
      The focus of this thesis is to investigate the feasibility of a lens-less label-free microscope system, and compare this with a conventional lens-based microscope. The imaging performance of conventional microscopes are greatly dependent on the objective lens, due to their inherent physical space constraint and spherical aberrations. We, therefore, will investigate the conceptual feasibility of a ...
    • Critical echo state network dynamics by means of Fisher information maximization 

      Bianchi, Filippo Maria; Livi, Lorenzo; Jenssen, Robert; Alippi, Cesare (Chapter; Bokkapittel, 2017-07-03)
      The computational capability of an Echo State Network (ESN), expressed in terms of low prediction error and high short-term memory capacity, is maximized on the so-called “edge of criticality”. In this paper we present a novel, unsupervised approach to identify this edge and, accordingly, we determine hyperparameters configuration that maximize network performance. The proposed method is ...
    • Temporal overdrive recurrent neural network 

      Bianchi, Filippo Maria; Kampffmeyer, Michael C.; Maiorino, Enrico; Jenssen, Robert (Chapter; Bokkapittel, 2017-07-03)
      In this work we present a novel recurrent neural network architecture designed to model systems characterized by multiple characteristic timescales in their dynamics. The proposed network is composed by several recurrent groups of neurons that are trained to separately adapt to each timescale, in order to improve the system identification process. We test our framework on time series prediction tasks ...
    • Large-Scale Mapping of Small Roads in Lidar Images Using Deep Convolutional Neural Networks 

      Salberg, Arnt Børre; Trier, Øivind Due; Kampffmeyer, Michael C. (Chapter; Bokkapittel, 2017-05-19)
      Detailed and complete mapping of forest roads is important for the forest industry since they are used for timber transport by trucks with long trailers. This paper proposes a new automatic method for large-scale mapping forest roads from airborne laser scanning data. The method is based on a fully convolutional neural network that performs end-to-end segmentation. To train the network, a large set ...
    • Eddy Detection in the Marginal Ice Zone with Sentinel-1 Data Using YOLOv5 

      Khachatrian, Eduard; Sandalyuk, Nikita V.; Lozou, Pigi (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-24)
      The automatic detection and analysis of ocean eddies in the marginal ice zone via remote sensing is a very challenging task but of critical importance for scientific applications and anthropogenic activities. Therefore, as one of the first steps toward the automation of the eddy detection process, we investigated the potential of applying YOLOv5, a deep convolutional neural network architecture, to ...
    • SAR and Passive Microwave Fusion Scheme: A Test Case on Sentinel-1/AMSR-2 for Sea Ice Classification 

      Khachatrian, Eduard; Dierking, Wolfgang; Chlaily, Saloua; Eltoft, Torbjørn; Dinessen, Frode; Hughes, Nick; Marinoni, Andrea (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-14)
      The most common source of information about sea ice conditions is remote sensing data, especially images obtained from synthetic aperture radar (SAR) and passive microwave radiometers (PMR). Here we introduce an adaptive fusion scheme based on Graph Laplacians that allows us to retrieve the most relevant information from satellite images. In a first test case, we explore the potential of sea ice ...
    • Droner som FKT - bruk av droner som forebyggende tiltak i beitenæringen 

      Winje, Erlend; Bjørn, Tor-Arne; Hansen, Inger; Meisingset, Erling; Haugen, Atilla; Heppelmann, Joachim Bernd; Myhre, Jonas Nordhaug; Wagner, Gabriela (Research report; Forskningsrapport, 2023)
      Utmarksbeitende dyr er utsatt for angrep fra fredet rovvilt. I oppdrag fra rovviltnemnda i region 6 Midt-Norge undersøker vi den mulige nytteverdien av droner i åpen kategori som forebyggende- og konfliktdempende tiltak (FKT). Utredningen er basert på informasjon fra intervjuer, faglitteratur og dronetestflygninger.Droner som FKT kan brukes under (1) tilsyn, (2) flytting av dyr fra rovdyrutsatte ...
    • Label-free superior contrast with c-band ultra-violet extinction microscopy 

      Wolfson, Deanna; Opstad, Ida Sundvor; Hansen, Daniel Henry; Mao, Hong; Ahluwalia, Balpreet Singh; Ströhl, Florian (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-03)
      In 1934, Frits Zernike demonstrated that it is possible to exploit the sample’s refractive index to obtain superior contrast images of biological cells. The refractive index contrast of a cell surrounded by media yields a change in the phase and intensity of the transmitted light wave. This change can be due to either scattering or absorption caused by the sample. Most cells are transparent at visible ...
    • Rapid prototyping of 1xN multifocus gratings via additive direct laser writing 

      Reischke, Marie; Vanderpoorten, Oliver; Ströhl, Florian (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-05)
      Multifocus gratings (MFGs) enable microscopes and other imaging systems to record entire Z-stacks of images in a single camera exposure. The exact grating shape depends on microscope parameters like wavelength and magnification and defines the multiplexing onto a grid of MxN Z-slices. To facilitate the swift production and alteration of MFGs for a system and application at hand, we have developed ...
    • Deep Semi-Supervised Semantic Segmentation in Multi-Frequency Echosounder Data 

      Choi, Changkyu; Kampffmeyer, Michael; Jenssen, Robert; Handegard, Nils Olav; Salberg, Arnt-Børre (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-01)
      Multi-frequency echosounder data can provide a broad understanding of the underwater environment in a non-invasive manner. The analysis of echosounder data is, hence, a topic of great importance for the marine ecosystem. Semantic segmentation, a deep learning based analysis method predicting the class attribute of each acoustic intensity, has recently been in the spotlight of the fisheries and aquatic ...