Viser treff 162-181 av 942

    • Deep divergence-based approach to clustering 

      Kampffmeyer, Michael C.; Løkse, Sigurd; Bianchi, Filippo Maria; Livi, Lorenzo; Salberg, Arnt Børre; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-08)
      A promising direction in deep learning research consists in learning representations and simultaneously discovering cluster structure in unlabeled data by optimizing a discriminative loss function. As opposed to supervised deep learning, this line of research is in its infancy, and how to design and optimize suitable loss functions to train deep neural networks for clustering is still an open question. ...
    • 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 ...
    • Deep Image Translation With an Affinity-Based Change Prior for Unsupervised Multimodal Change Detection 

      Luppino, Luigi Tommaso; Kampffmeyer, Michael; Bianchi, Filippo Maria; Moser, Gabriele; Serpico, Sebastiano Bruno; Jenssen, Robert; Anfinsen, Stian Normann (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-17)
      Image translation with convolutional neural networks has recently been used as an approach to multimodal change detection. Existing approaches train the networks by exploiting supervised information of the change areas, which, however, is not always available. A main challenge in the unsupervised problem setting is to avoid that change pixels affect the learning of the translation function. We propose ...
    • The deep kernelized autoencoder 

      Kampffmeyer, Michael C.; Løkse, Sigurd; Bianchi, Filippo Maria; Jenssen, Robert; Livi, Lorenzo (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 ...
    • Deep kernelized autoencoders 

      Kampffmeyer, Michael C.; Løkse, Sigurd; Bianchi, Filippo Maria; Jenssen, Robert; Livi, Lorenzo (Peer reviewed; Book; Bokkapittel; Bok; Chapter, 2017-05-19)
      In this paper we introduce the deep kernelized autoencoder, a neural network model that allows an explicit approximation of (i) the mapping from an input space to an arbitrary, user-specified kernel space and (ii) the back-projection from such a kernel space to input space. The proposed method is based on traditional autoencoders and is trained through a new unsupervised loss function. ...
    • A deep learning approach for anomaly identification in PZT sensors using point contact method 

      Kalimullah, Nur M M; Shelke, Amit; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-21)
      The implementation of piezoelectric sensors is degraded due to surface defects, delamination, and extreme weathering conditions, to mention a few. Hence, the sensor needs to be diagnosed before the efficacious implementation in the structural health monitoring (SHM) framework. To rescue the problem, a novel experimental method based on Coulomb coupling is utilised to visualise the evolution of ...
    • Deep learning architecture “LightOCT” for diagnostic decision support using optical coherence tomography images of biological samples 

      Butola, Ankit; Prasad, Dilip Kumar; Ahmad, Azeem; Dubey, Vishesh Kumar; Qaiser, Darakhshan; Srivastava, Anurag; Senthilkumaran, Paramasivam; Ahluwalia, Balpreet Singh; Mehta, Dalip Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-13)
      Optical coherence tomography (OCT) is being increasingly adopted as a label-free and non-invasive technique for biomedical applications such as cancer and ocular disease diagnosis. Diagnostic information for these tissues is manifest in textural and geometric features of the OCT images, which are used by human expertise to interpret and triage. However, it suffers delays due to the long process of ...
    • Deep microlocal reconstruction for limited-angle tomography 

      Andrade-Loarca, Héctor; Kutyniok, Gitta Astrid Hildegard; Öktem, Ozan; Petersen, Philipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-04)
      We present a deep-learning-based algorithm to jointly solve a reconstruction problem and a wavefront set extraction problem in tomographic imaging. The algorithm is based on a recently developed digital wavefront set extractor as well as the well-known microlocal canonical relation for the Radon transform. We use the wavefront set information about x-ray data to improve the reconstruction ...
    • Deep Reinforcement Learning for Query-Conditioned Video Summarization 

      Zhang, Yujia; Kampffmeyer, Michael C.; Zhao, Xiaoguang; Tan, Min (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 ...
    • 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 ...
    • Deep Semisupervised Teacher–Student Model Based on Label Propagation for Sea Ice Classification 

      Khaleghian, Salman; Ullah, Habib; Kræmer, Thomas; Eltoft, Torbjørn; Marinoni, Andrea (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-14)
      In this article, we propose a novelteacher–student-based label propagation deep semisupervised learning (TSLP-SSL) method for sea ice classification based on Sentinel-1 synthetic aperture radar data. For sea ice classification, labeling the data precisely is very time consuming and requires expert knowledge. Our method efficiently learns sea ice characteristics from a limited number of labeled samples ...
    • Delt situasjonsforståelse under søk og redning i nordområdene 

      Haugstveit, Ida Maria; Skjetne, Jan Håvard; Walderhaug, Ståle; Antonsen, yngve; Ellingsen, May-Britt; Håheim-Saers, Nils; Heggelund, Yngve; Anfinsen, Stian Normann (Research report; Forskningsrapport, 2016-05-03)
      Prosjektets mål er å bidra til økt kunnskap om hvordan etablere delt situasjonsforståelse mellom sentrale aktører innen SAR i Nordområdet. Prosjektgruppa har arbeidet ut ifra en menneske-teknologi-organisasjon (MTO) tilnærming og hvor vi har sett på <br>1) menneskelige og organisatoriske faktorer og <br>2) tekniske faktorer som virker inn på etableringen av delt situasjonsforståelse mellom aktører.<br> ...
    • Demonstrating low Raman background in UV-written SiO2 waveguides 

      Jensen, Mathias Novik; Gates, James C.; Flint, Alex I.; Hellesø, Olav Gaute (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-06)
      Raman spectroscopy can give a chemical ’fingerprint’ from both inorganic and organic samples, and has become a viable method of measuring the chemical composition of single biological particles. In parallel, integration of waveguides and microfluidics allows for the creation of miniaturized optical sensors in lab-on-a-chip devices. The prospect of combining integrated optics and Raman spectroscopy ...
    • Demystifying speckle field interference microscopy 

      Ahmad, Azeem; Jayakumar, Nikhil; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-27)
      Dynamic speckle illumination (DSI) has recently attracted strong attention in the feld of biomedical imaging as it pushes the limits of interference microscopy (IM) in terms of phase sensitivity, and spatial and temporal resolution compared to conventional light source illumination. To date, despite conspicuous advantages, it has not been extensively implemented in the feld of phase imaging due ...
    • Dense dilated convolutions merging network for land cover classification 

      Liu, Qinghui; Kampffmeyer, Michael; Jenssen, Robert; Salberg, Arnt Børre (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-06)
      Land cover classification of remote sensing images is a challenging task due to limited amounts of annotated data, highly imbalanced classes, frequent incorrect pixel-level annotations, and an inherent complexity in the semantic segmentation task. In this article, we propose a novel architecture called the dense dilated convolutions' merging network (DDCM-Net) to address this task. The proposed ...
    • The Departure from Mixed-Layer Similarity During the Afternoon Decay of Turbulence in the Free-Convective Boundary Layer: Results from Large-Eddy Simulations 

      Elguernaoui, Omar; Reuder, Joachim; Li, Dan; Maronga, Bjørn; Bakhoday Paskyabi, Mostafa; Wolf, Tobias; Esau, Igor (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-21)
      This study analyses the departure of the velocity-variances profiles from their quasi-steady state described by the mixed-layer similarity, using large-eddy simulations with different prescribed shapes and time scales of the surface kinematic heat flux decay. Within the descriptive frames where the time is tracked solely by the forcing time scale (either constant or time-dependent) describing the ...
    • Derivation of vertical wavelengths of gravity waves in the MLT-region from multispectral airglow observations 

      Schmidt, Carsten; Dunker, Tim; Lichtenstern, Sabrina; Scheer, Jürgen; Wüst, Sabine; Hoppe, Ulf-Peter; Bittner, Michael (Journal article; Tidsskriftartikkel; Peer reviewed; Preprint; Manuskript, 2018-03-06)
      <p>We present the derivation of gravity wave vertical wavelengths from OH airglow observations of different vibrational transitions. It utilizes small phase shifts regularly observed between the OH(3-1) and OH(4-2) intensities in the spectra of the GRIPS (GRound-based Infrared P-branch Spectrometer) instruments, which record the OH airglow emissions in the wavelength range from 1.5  μm to 1.6  μm ...
    • Deriving high contrast fluorescence microscopy images through low contrast noisy image stacks 

      Acuna Maldonado, Sebastian Andres; ROY, MAYANK; Villegas, Luis; Dubey, Vishesh Kumar; Ahluwalia, Balpreet Singh; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-11)
      Contrast in fluorescence microscopy images allows for the differentiation between different structures by their difference in intensities. However, factors such as point-spread function and noise may reduce it, affecting its interpretability. We identified that fluctuation of emitters in a stack of images can be exploited to achieve increased contrast when compared to the average and Richardson-Lucy ...
    • Detecting and Interpreting Faults in Vulnerable Power Grids With Machine Learning 

      Chiesa, Matteo; Bianchi, Filippo Maria; Eikeland, Odin Foldvik; Holmstrand, Inga Setså; Bakkejord, Sigurd (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-10)
      Unscheduled power disturbances cause severe consequences both for customers and grid operators. To defend against such events, it is necessary to identify the causes of interruptions in the power distribution network. In this work, we focus on the power grid of a Norwegian community in the Arctic that experiences several faults whose sources are unknown. First, we construct a data set consisting ...
    • Detecting the linear and non-linear causal links for disturbances in the power grid 

      Foldvik Eikeland, Odin; Bianchi, Filippo Maria; Holmstrand, Inga Setsa; Bakkejord, Sigurd; Chiesa, Matteo (Chapter; Bokkapittel, 2021)
      Unscheduled power disturbances cause severe consequences for customers and grid operators. To avoid suchevents, it is important to identify the causes and localize the sources of the disturbances in the power distribution network. In this work, we focus on a specific power grid in the Arctic region of Northern Norway that experiences an increased frequency of failures of unspecified origin.