Viser treff 21-40 av 942

    • Strongly intermittent far scrape-off layer fluctuations in Alcator C-Mod plasmas close to the empirical discharge density limit 

      Ahmed, Sajidah; Garcia, Odd Erik; Q Kuang, Adam; LaBombard, Brian; L Terry, James; Theodorsen, Audun (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-07)
      Intermittent plasma fluctuations in the boundary region of the Alcator C-Mod device were comprehensively investigated using data time-series from gas puff imaging and mirror Langmuir probe diagnostics. Fluctuations were sampled during stationary plasma conditions in ohmically heated, lower single null diverted configurations with scans in both line-averaged density and plasma current, with Greenwald ...
    • On the Effects of Self-supervision and Contrastive Alignment in Deep Multi-view Clustering 

      Trosten, Daniel Johansen; Løkse, Sigurd Eivindson; Jenssen, Robert; Kampffmeyer, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-22)
      Self-supervised learning is a central component in recent approaches to deep multi-view clustering (MVC). However, we find large variations in the development of self-supervision-based methods for deep MVC, potentially slowing the progress of the field. To address this, we present Deep-MVC, a unified framework for deep MVC that includes many recent methods as instances. We leverage our framework to ...
    • Supercm: Revisiting Clustering for Semi-Supervised Learning 

      Singh, Durgesh Kumar; Boubekki, Ahcene; Jenssen, Robert; Kampffmeyer, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-05)
      The development of semi-supervised learning (SSL) has in recent years largely focused on the development of new consistency regularization or entropy minimization approaches, often resulting in models with complex training strategies to obtain the desired results. In this work, we instead propose a novel approach that explicitly incorporates the underlying clustering assumption in SSL through extending ...
    • Using a large open clinical corpus for improved ICD-10 diagnosis coding 

      Lamproudis, Anastasios; Olsen Svenning, Therese; Torsvik, Torbjørn; Chomutare, Taridzo Fred; Budrionis, Andrius; Ngo, Phuong Dinh; Vakili, Thomas; Dalianis, Hercules (Journal article; Tidsskriftartikkel, 2023)
      With the recent advances in natural language processing and deep learning, the development of tools that can assist medical coders in ICD-10 diagnosis coding and increase their efficiency in coding discharges ummaries is significantly more viable than before. To that end, one important component in the development of these models is the datasets used to train them. In this study, such datasets are ...
    • Optical trapping in air on a single interference fringe 

      Schäpers, Aaron; Hellesø, Olav Gaute; Fick, Jochen (Journal article; Tidsskriftartikkel, 2023)
      Stable and reproducible trapping in air of 1 µm and 500 nm dielectric particles has been realized using a dual beam optical fiber tweezers with cleaved commercial single mode fibers. The influence of the interference fringes of the two coherent and counter-propagating trapping beam is investigated by controlling the fringe visibility. Optical trapping on a series of upto10 fringes or trapping on ...
    • The Meta-Evaluation Problem in Explainable AI: Identifying Reliable Estimators with MetaQuantus 

      Wickstrøm, Kristoffer Knutsen; Höhne, Marina Marie-Claire (Journal article; Tidsskriftartikkel, 2023)
      Explainable AI (XAI) is a rapidly evolving field that aims to improve transparency and trustworthiness of AI systems to humans. One of the unsolved challenges in XAI is estimating the performance of these explanation methods for neural networks, which has resulted in numerous competing metrics with little to no indication of which one is to be preferred. In this paper, to identify the most reliable ...
    • DiffCloth: Diffusion Based Garment Synthesis and Manipulation via Structural Cross-modal Semantic Alignment 

      Zhang, Xujie; Yang, Binbin; Kampffmeyer, Michael Christian; Zhang, Wenqing; Zhang, Shiyue; Lu, Guansong; Lin, Liang; Xu, Hang; Liang, Xiaodan (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-15)
      Cross-modal garment synthesis and manipulation will significantly benefit the way fashion designers generate garments and modify their designs via flexible linguistic interfaces. However, despite the significant progress that has been made in generic image synthesis using diffusion models, producing garment images with garment part level semantics that are well aligned with input text prompts and ...
    • Coordinate Transformer: Achieving Single-stage Multi-person Mesh Recovery from Videos 

      Li, Haoyuan; Dong, Haoye; Jia, Hanchao; Huang, Dong; Kampffmeyer, Michael Christian; Lin, Liang; Liang, Xiaodan (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-15)
      Multi-person 3D mesh recovery from videos is a critical first step towards automatic perception of group behavior in virtual reality, physical therapy and beyond. However, existing approaches rely on multi-stage paradigms, where the person detection and tracking stages are performed in a multi-person setting, while temporal dynamics are only modeled for one person at a time. Consequently, their ...
    • Exploring the Potential of Sentinel-1 Ocean Wind Field Product for Near-Surface Offshore Wind Assessment in the Norwegian Arctic 

      Khachatrian, Eduard; Asemann, Patricia; Lihong, Zhou; Birkelund, Yngve; Ezau, Igor; Ricaud, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-24)
      The exploitation of offshore wind resources is a crucial step towards a clean energy future. It requires an advanced approach for high-resolution wind resource evaluations. We explored the suitability of the Sentinel-1 Level-2 OCN ocean wind field (OWI) product for offshore wind resource assessments. The SAR data were compared to in situ observations and three reanalysis products: the global ...
    • A Comparison Between Oil-to-Water Volumetric Fractions Derived from L-Band Synthetic Aperture Radar Imagery and in Situ Samples 

      Quigley, Cornelius Patrick; Johansson, Malin; Jones, Cathleen Elaine; Garcia, Óscar; Monaldo, Frank (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-20)
      We compare in-situ water volume measurements of mineral oil emulsion sampled from an oil slick in Santa Barbara, California, to acquisitions of airborne UAVSAR data acquired in June 2022. Estimating the water-to-oil fraction using the UAVSAR imagery, we find that low SNR in the co- and cross-polarimetric channels limits this capability above a certain oil-to-water volumetric threshold. Higher SNR ...
    • Hubs and Hyperspheres: Reducing Hubness and Improving Transductive Few-shot Learning with Hyperspherical Embeddings 

      Trosten, Daniel Johansen; Chakraborty, Rwiddhi; Løkse, Sigurd Eivindson; Wickstrøm, Kristoffer; Jenssen, Robert; Kampffmeyer, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-22)
      Distance-based classification is frequently used in transductive few-shot learning (FSL). However, due to the high-dimensionality of image representations, FSL classifiers are prone to suffer from the hubness problem, where a few points (hubs) occur frequently in multiple nearest neighbour lists of other points. Hubness negatively impacts distance-based classification when hubs from one class appear ...
    • A southern, middle, and northern Norwegian offshore wind energy resources analysis by a transfer learning method for Energy Internet 

      Chen, Hao; Birkelund, Yngve; Ricaud, Benjamin; Zhang, Qixia (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      As renewable energy sources offshore wind energy develop quickly, countries like Norway with long coastlines are exploring their potential. However, the diverse wind resources across different regions of Norway present challenges for study for effective utilization of offshore wind energy. This study proposes a novel method that utilizes transfer learning techniques to analyse the resource differences ...
    • Self-Supervised Few-Shot Learning for Ischemic Stroke Lesion Segmentation 

      Tomasetti, Luca; Hansen, Stine; Khanmohammadi, Mahdieh; Engan, Kjersti; Høllesli, Liv Jorunn; Kurz, Kathinka Dæhli; Kampffmeyer, Michael Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-01)
      Precise ischemic lesion segmentation plays an essential role in improving diagnosis and treatment planning for ischemic stroke, one of the prevalent diseases with the highest mortality rate. While numerous deep neural network approaches have recently been proposed to tackle this problem, these methods require large amounts of annotated regions during training, which can be impractical in the medical ...
    • Improvements in September Arctic Sea Ice Predictions Via Assimilation of Summer CryoSat-2 Sea Ice Thickness Observations 

      Zhang, Yong-Fei; Bushuk, Mitchell; Winton, Michael; Hurlin, Bill; Gregory, William; Landy, Jack Christopher; Jia, Liwei (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-15)
      Because of a spring predictability barrier, the seasonal forecast skill of Arctic summer sea ice is limited by the availability of melt-season sea ice thickness (SIT) observations. The first year-round SIT observations, retrieved from CryoSat-2 from 2011 to 2020, are assimilated into the GFDL ocean–sea ice model. The model's SIT anomaly field is brought into significantly better agreement with the ...
    • A Contextually Supported Abnormality Detector for Maritime Trajectories 

      Olesen, Kristoffer Vinther; Boubekki, Ahcene; Kampffmeyer, Michael Christian; Jenssen, Robert; Christensen, Anders Nymark; Hørlück, Sune; Clemmensen, Line H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-31)
      The analysis of maritime traffic patterns for safety and security purposes is increasing in importance and, hence, Vessel Traffic Service operators need efficient and contextualized tools for the detection of abnormal maritime behavior. Current models lack interpretability and contextualization of their predictions and are generally not quantitatively evaluated on a large annotated dataset comprising ...
    • Mapping the extent of giant Antarctic icebergs with deep learning 

      Braakmann-Folgmann, Anne Christina; Shepherd, Andrew; Hogg, David; Redmond, Ella (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-09)
      Icebergs release cold, fresh meltwater and terrigenous nutrients as they drift and melt, influencing the local ocean properties, encouraging sea ice formation and biological production. To locate and quantify the fresh water flux from Antarctic icebergs, changes in their area and thickness have to be monitored along their trajectories. While the locations of large icebergs are operationally tracked ...
    • ADNet++: A few-shot learning framework for multi-class medical image volume segmentation with uncertainty-guided feature refinement 

      Hansen, Stine; Gautam, Srishti; Salahuddin, Suaiba Amina; Kampffmeyer, Michael Christian; Jenssen, Robert (Journal article; Tidsskriftartikkel, 2023-08-02)
      A major barrier to applying deep segmentation models in the medical domain is their typical data-hungry nature, requiring experts to collect and label large amounts of data for training. As a reaction, prototypical few-shot segmentation (FSS) models have recently gained traction as data-efficient alternatives. Nevertheless, despite the recent progress of these models, they still have some essential ...
    • GNSS Scintillations in the Cusp, and the Role of Precipitating Particle Energy Fluxes 

      Ivarsen, Magnus Fagernes; Jin, Yaqi; Spicher, Andres; St-Maurice, Jean-Pierre; Park, Jaeheung; Billett, Daniel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-16)
      Using a large data set of ground-based GNSS scintillation observations coupled with in situ particle detector data, we perform a statistical analysis of both the input energy flux from precipitating particles, and the observed occurrence of density irregularities in the northern hemisphere cusp. By examining trends in the two data sets relating to geomagnetic activity, we conclude that observations ...
    • Automated tilt compensation in acoustic microscopy 

      Gupta, Shubham Kumar; Habib, Anowarul; Kumar, Prakhar; Melandsø, Frank; Ahmad, Azeem (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-12)
      Scanning acoustic microscopy (SAM) is a potent and nondestructive technique capable of producing three-dimensional topographic and tomographic images of specimens. This is achieved by measuring the differences in time of flight (ToF) of acoustic signals emitted from various regions of the sample. The measurement accuracy of SAM strongly depends on the ToF measurement, which is affected by tilt in ...
    • View it like a radiologist: Shifted windows for deep learning augmentation of CT images 

      Østmo, Eirik Agnalt; Wickstrøm, Kristoffer; Radiya, Keyur; Kampffmeyer, Michael; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-23)
      Deep learning has the potential to revolutionize medical practice by automating and performing important tasks like detecting and delineating the size and locations of cancers in medical images. However, most deep learning models rely on augmentation techniques that treat medical images as natural images. For contrast-enhanced Computed Tomography (CT) images in particular, the signals producing the ...