• A Field Programmable and Dynamic Configurable Power Electronic Converter Concept 

      Hoff, Bjarte (Chapter; Bokkapittel, 2022)
      This paper proposes the concept of a field programmable and configurable power electronic converter together with a new synthesis method. By considering the converter as a pack of resources, the converter topology and configuration of inputs and outputs can be programmed in the field through, utilising the available device resources.
    • First-year engineering students’ mathematics task performance and its relation to their motivational values and views about mathematics 

      Tossavainen, Timo; Rensaa, Ragnhild Johanne; Haukkanen, Pentti; Mattila, Mika; Johansson, Monica (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-26)
      This study investigates Finnish, Norwegian, and Swedish first-year engineering students’ task performance in mathematics and examines how it relates to their motivational values and beliefs about the nature of mathematics. In a set of seven mathematical tasks, female students outperformed male students, for example, in the simplification of symbolic expressions. Our findings also show that ...
    • Framework for Modeling and Simulation of Household Appliances 

      Bjerknes Nilsen, Christian; Hoff, Bjarte; Østrem, Trond (Peer reviewed; Book; Chapter, 2018-12-31)
      This paper describes a framework for simulating household appliances in Simulink. Typical Norwegian household equipment have been analyzed based on their characteristic behavior, to establish the requirement for synthesizing and recreating their current waveform, harmonic currents and phase shift. Both detailed simulation of the current waveform and RMS currents for simulation over longer time periods ...
    • Framework for Modeling and Simulation of Household Appliances 

      Bjerknes Nilsen, Christian; Hoff, Bjarte; Østrem, Trond (Peer reviewed; Chapter, 2018-12-31)
      This paper describes a framework for simulating household appliances in Simulink. Typical Norwegian household equipment have been analyzed based on their characteristic behavior, to establish the requirement for synthesizing and recreating their current waveform, harmonic currents and phase shift. Both detailed simulation of the current waveform and RMS currents for simulation over longer time periods ...
    • Gender perspectives on a flipped classroom environment 

      Rensaa, Ragnhild Johanne; Fredriksen, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-20)
      The present paper investigates the gender perspective of flipped classroom. In particular, it considers how the collaborative setting of in-class group-work affect the female population of students. The paper draws on an in-depth analysis of the interview with one such student. The focus of this interview was on interactional collaboration between peers during group work activities in a ...
    • Home Load Disaggregation using Deep Learning and Bayesian Optimization: A Case Study in Arctic Climate in Northern Norway 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2023-08-03)
      Load monitoring is an essential task in energy management systems. In this paper, an approach that relies on a long short-term memory (LSTM) model and a discrete wavelet transform (DWT) filter is presented to estimate the energy usage of flexible appliances. In the preprocessing stage, the main features of the aggregated power signal are extracted using DWT. Deep learning methods are very sensitive ...
    • Improving Geopolymer Characteristics with Addition of Poly-Vinyl Alcohol (PVA) Fibers 

      Ekaputri, Januarti Jaya; Fujiyama, Chikako; Chijiwa, Nobuhiro; Ho, Tu Dac; Nguyen, Hung Thanh (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-20)
      This paper presents the benefits of PVA fibers in improving the mechanical properties of class F fly-ash-based geopolymer concrete. The activator used in the geopolymer was 8M sodium hydroxide (NaOH) and sodium silicate (Na<sub>2</sub>SiO<sub>3</sub>), with a mass ratio of Na<sub>2</sub>SiO<sub>3</sub> to NaOH varied from 1.5 to 2.5. Cylindrical specimens with a diameter of 100 mm and a height of ...
    • Ingeniørstudenters bruk av læringsverktøy i et lineær algebraemne : hvilken rolle spiller nettbaserte forelesninger? 

      Rensaa, Ragnhild Johanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-11)
      I denne artikkelen diskuteres studentenes bruk av læringsverktøy med spesielt fokus på et nettbasert tilbud. Egne forelesninger i et emne i lineær algebra for master ingeniørstudenter, fjerde år, har blitt streamet og publisert, og jeg har undersøkt hvordan studentene har brukt disse forelesningene. Data er innsamlet første og tredje gang dette ble gjort, og hovedvekten i denne artikkelen er lagt ...
    • Interpreting teaching for conceptual and for procedural knowledge in a teaching video about linear algebra 

      Rensaa, Ragnhild Johanne; Vos, Pauline (Journal article; Tidsskriftartikkel, 2018)
      The aim of this study is to investigate teaching videos about mathematics, seeking to uncover research-based foundations for their quality. By drawing on the notions of procedural and conceptual knowledge, the research was operationalized by asking professionals in undergraduate mathematics education (n=18) to interpret sections of a teaching video. The video dealt with a topic in linear algebra. ...
    • Investigation of wireless electrification for a reconfigurable manufacturing cell 

      Al-Sallami, Hussein Mahdi Yaseen; Arnarson, Halldor; Solvang, Bjørn; Bremdal, Bernt Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-24)
      Reconfigurable manufacturing systems (RMS) with a rearrangeable structure can quickly adjust their productivity to meet the dynamic market changes and the demand for high-variety products. Industry 4.0 technologies have enhanced the RMS flexibility and made the automation of the reconfiguration of the manufacturing system possible. As an Industry 4.0 technology, wireless power transfer (WPT) can ...
    • Investigation of wireless electrification for a reconfigurable manufacturing cell 

      Al-Sallami, Hussein Mahdi Yaseen; Arnarson, Halldor; Solvang, Bjørn; Bremdal, Bernt Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-24)
      Reconfigurable manufacturing systems (RMS) with a rearrangeable structure can quickly adjust their productivity to meet the dynamic market changes and the demand for high-variety products. Industry 4.0 technologies have enhanced the RMS flexibility and made the automation of the reconfiguration of the manufacturing system possible. As an Industry 4.0 technology, wireless power transfer (WPT) can ...
    • Keeping track of samples in multidisciplinary fieldwork 

      Ellingsen, Pål Gunnar; Ferrighi, Lara; Godøy, Øystein Arne; Gabrielsen, Tove M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-10)
      We here present methods, tools and results for efficiently collecting metadata and tracking samples collected in the field. The samples and metadata were collected during scientific cruises conducted by amongst others marine biologists, oceanographers, geochemists and marine geologists in the Nansen Legacy project. It is here reported on the successful development and implementation of a system ...
    • Load modeling from smart meter data using neural network methods 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2021)
      Electricity load modeling plays a critical role to conduct load forecasting or other applications such as non-intrusive load monitoring. For such a reason, this paper investigates a comparison study of two common artificial neural network methods (Multilayer perceptron (MLP) and radial basis function neural network (RBF-NN) for home load modeling application. The accuracy of load modeling using ...
    • Maximum Available Power of Undersea Capacitive Coupling in a Wireless Power Transfer System 

      Al-Sallami, Hussein; Hoff, Bjarte; Østrem, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-23)
      This paper studies the maximum available power of a dissipative capacitive power transfer (CPT) system submerged in seawater. The CPT system's maximum power capability is driven using the network theory, precisely the conjugate-image approach. The equations of the maximum available load power and the system's corresponding efficiency are expressed as a function of the capacitive coupling parameters. ...
    • Mode division multiplexing free space optics system with 3D hybrid modulation under dust and fog 

      Pottoo, Sahil Nazir (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-13)
      Mode division multiplexing (MDM) is an emerging information transmission technique in which multiple data signals can be transmitted simultaneously on different modes of a single wavelength laser beam over a free-space channel. MDM is a potential technique for the realization of high-speed spectral efficient communication links for future generations of wireless networks. We present a novel MDM-based ...
    • Modeling and Attitude Control of Satellites in Elliptical Orbits 

      Oland, Espen (Peer reviewed; Chapter, 2018-11-05)
      The attitude determination and control system (ADCS) for spacecraft is responsible for determining its orientation using sensor measurements and then applying actuation forces to change the orientation. This chapter details the different components required for a complete attitude determination and control system for satellites moving in elliptical orbits. Specifically, the chapter details the orbital ...
    • Modelling and simulation of interaction forces in tugboat-assisted docking of large marine vessels 

      Kristiansen, Raymond; Ørke, Henning; Gravdahl, Jan Tommy (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-22)
      In this paper, we address modelling and simulation of dynamics involved in docking of large marine vessels with aid of tugboats, with the aim of providing a tool for improved design of control algorithms for autonomous docking operations. Mathematical models of the docking vessel and tugboats in 3DOF are derived, with a special focus on realistic interactions through towline, contact and friction ...
    • Modified demagnetisation control strategy for low-voltage ride-through enhancement in DFIG-based wind systems 

      Senapati, Manoj Kumar; Nayak, Paresh Kumar; Padmanaban, Sanjeevikumar; Gjengedal, Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-16)
      The large-scale wind energy conversion systems (WECSs) based on doubly-fed induction generators (DFIGs) are very popular in recent years due to the numerous technical and economic benefits. With the increasing penetration level of wind energy, the latest grid codes require the DFIG-based WECSs to remain connected to the grid under grid fault scenarios and deliver the required reactive power into ...
    • A Modified Version of the IEEE 39-bus Test System for the Day-Ahead Market 

      Tricarico, Gioacchino; Wagle, Raju; Dicorato, Maria; Forte, Giuseppe; Gonzalez-Longatt, Francisco; Rueda, Jose Luis (Chapter; Bokkapittel, 2023-03-28)
      Reaching net-zero emissions within the proposed time requires an enormous effort from the energy sector, and it is even more challenging for the electricity infrastructure. This article offers a modified version of the IEEE 39-bus system specifically created to allow zonal day-ahead market (ZDAM) simulations. The system representation is based on the original version of the IEEE 39-bus system but ...
    • Når blir skipsfarten grønn? 

      Hoff, Bjarte; Østrem, Trond (Kronikk; Chronicle, 2018-04-25)
      n av utfordringene i forbindelse med dagens skipsfart er utslipp til luft, hovedsakelig karbondioksid og nitrogenoksider. Disse utslippene er knyttet til oljefyrte forbrenningsmotorer som dominerer dagens skipsflåte. Det er overveiende sannsynlig at det er en direkte sammenheng mellom global oppvarming og utslipp av klimagasser. Utslipp til luft kan også bidra til sur nedbør og svevestøv, for å nevne ...