• Analysis of full-scale riser responses in field conditions based on Gaussian mixture model 

      Wu, Jie; Eidnes, Sølve; Jin, Jingzhe; Lie, Halvor; Yin, Decao; Passano, Elizabeth Anne; Sævik, Svein; Riemer-Sørensen, Signe (Peer reviewed; Journal article, 2022)
      Offshore slender marine structures experience complex and combined load conditions from waves, current and vessel motions that may result in both wave frequency and vortex shedding response patterns. Field measurements ...
    • Anomaly Detection with Unknown Anomalies: Application to Maritime Machinery 

      Michalowska, Katarzyna; Riemer-Sørensen, Signe; Sterud, Camilla; Hjellset, Ole Magnus (Peer reviewed; Journal article, 2021)
      We present a framework for deriving anomaly detection algorithms on timeseries data when the time and expression of anomalous behaviour is unknown. The framework is suited for problems in which individual machine learning ...
    • Balancing the Norwegian regulated power market anno 2016 to 2022 

      Austnes, Pål Forr; Riemer-Sørensen, Signe; Bordvik, David Andreas; Andresen, Christian Andre (Peer reviewed; Journal article, 2024)
      The balancing market for power is designed to account for the difference between predicted supply/demand of electricity and the realised supply/demand. However, increased electrification of society changes the consumption ...
    • Deep Reinforcement Learning for Long Term Hydropower Production Scheduling 

      Riemer-Sørensen, Signe; Rosenlund, Gjert Hovland (Chapter; Peer reviewed, 2020)
      We explore the use of deep reinforcement learning to provide strategies for long term scheduling of hydropower production. We consider a use-case where the aim is to optimise the yearly revenue given week-by-week inflows ...
    • Graph Convolutional Networks for probabilistic power system operational planning 

      Sheikh-Mohamed, Yasmin Bashir; Jakobsen, Sigurd Hofsmo; Bødal, Espen Flo; Haugseth, Fredrik Marinius; Kiel, Erlend Sandø; Riemer-Sørensen, Signe (Chapter; Peer reviewed, 2023)
      Probabilistic operational planning of power systems usually requires computationally intensive and time consuming simulations. The method presented in this paper provides a time efficient alternative to predict the ...
    • Improved VIV Response Prediction Using Adaptive Parameters and Data Clustering 

      Wu, Jie; Yin, Decao; Lie, Halvor; Riemer-Sørensen, Signe; Sævik, Svein; Triantafyllou, Michael (Peer reviewed; Journal article, 2020)
      Slender marine structures such as deep-water riser systems are continuously exposed to currents, leading to vortex-induced vibrations (VIV) of the structure. This may result in amplified drag loads and fast accumulation ...
    • Inferring feature importance with uncertainties with application to large genotype data 

      Johnsen, Pål Vegard; Strumke, Inga; Langaas, Mette; DeWan, Andrew Thomas; Riemer-Sørensen, Signe (Peer reviewed; Journal article, 2023)
      Estimating feature importance, which is the contribution of a prediction or several predictions due to a feature, is an essential aspect of explaining data-based models. Besides explaining the model itself, an equally ...
    • A Levenberg-Marquardt Algorithm for Sparse Identification of Dynamical Systems 

      Haring, Mark A. M.; Grøtli, Esten Ingar; Riemer-Sørensen, Signe; Seel, Katrine; Hanssen, Kristian Gaustad (Peer reviewed; Journal article, 2022)
      Low complexity of a system model is essential for its use in real-time applications. However, sparse identification methods commonly have stringent requirements that exclude them from being applied in an industrial setting. ...
    • Mutual information estimation for graph convolutional neural networks 

      Landsverk, Marius; Riemer-Sørensen, Signe (Peer reviewed; Journal article, 2022)
      Measuring model performance is a key issue for deep learning practitioners. However, we often lack the ability to explain why a specific architecture attains superior predictive accuracy for a given data set. Often, ...
    • A new method for exploring gene–gene and gene–environment interactions in GWAS with tree ensemble methods and SHAP values 

      Johnsen, Pål Vegard; Riemer-Sørensen, Signe; DeWan, Andrew Thomas; Cahill, Megan E.; Langaas, Mette (Peer reviewed; Journal article, 2021)
      Background The identification of gene–gene and gene–environment interactions in genome-wide association studies is challenging due to the unknown nature of the interactions and the overwhelmingly large number of possible ...
    • Predictions of prices and volumes in the Nordic balancing markets for electricity 

      Backe, Stian; Riemer-Sørensen, Signe; Bordvik, David Andreas; Tiwari, Shweta; Andresen, Christian Andre (International Conference on the European Energy Market;19, Chapter; Peer reviewed, 2023)
      The electricity market is driven by complicated interactions that are hard to model analytically. This is particularly the case for the balancing market, where imbalances between supply and demand after the day-ahead market ...
    • Pseudo-Hamiltonian neural networks with state-dependent external forces 

      Stasik, Alexander Johannes; Sterud, Camilla; Bøhn, Eivind Eigil; Riemer-Sørensen, Signe (Peer reviewed; Journal article, 2023)
      Hybrid machine learning based on Hamiltonian formulations has recently been successfully demonstrated for simple mechanical systems, both energy conserving and not energy conserving. We introduce a pseudo-Hamiltonian ...
    • A supervised learning approach for optimal selection of bidding strategies in reservoir hydro 

      Riddervold, Hans Ole; Riemer-Sørensen, Signe; Szederjesi, Peter; Korpås, Magnus (Peer reviewed; Journal article, 2020)
      Power producers use a wide range of decision support systems to manage and plan for sales in the day-ahead electricity market. The available tools have advantages and disadvantages and the operators are often faced with ...
    • A supervised learning approach for optimal selection of bidding strategies in reservoir hydro 

      Riddervold, Hans Ole; Riemer-Sørensen, Signe; Szederjesi, Peter; Korpås, Magnus (Peer reviewed; Journal article, 2020)
      Power producers use a wide range of decision support systems to manage and plan for sales in the day-ahead electricity market. The available tools have advantages and disadvantages and the operators are often faced with ...
    • A tree based classifier for transient stability prediction following island splitting 

      Kiel, Erlend Sandø; Jakobsen, Sigurd Hofsmo; Haugen, Eirik; Lundemo, Sondre Duna; Riemer-Sørensen, Signe; Remonato, Filippo (Chapter, 2022)
      An unexpected failure or outage of one or multiple system components can cause a new operational situation that requires remedial actions. An important remedial action to model correctly is islanding. Finding the transient ...