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norskBlar i tittel Artikler, rapporter og annet (elektroteknologi)
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Når blir skipsfarten grønn?
(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 ... -
Non-directional Overcurrent Protection Relay Testing Using Virtual Hardware-in-the-Loop Device
(Chapter; Bokkapittel, 2023-05-17)Protective relays are an integral part of the power grid, making it reliable and secure against abnormal conditions. Hardware-in-the-Loop (HIL) can be employed to test and validate digital protective relay devices in the real-time simulation comprising hardware and software before actual implementation. However, the HIL technique requires a complex and high-cost technical environment consisting of ... -
Norwegian freshmen engineering students' self-efficacy, motivation, and view of mathematics in light of task performance
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-15)We report on 71 Norwegian freshmen engineering students' self-efficacy and motivation in mathematics. Students' responses to five-point Likert scales were analysed across three groups corresponding to different performance levels on a set of mathematical tasks. The groups were investigated to trace differences in self-efficacy, motivation, and the epistemological beliefs about the nature of mathematics. ... -
Norwegian, Swedish, and Finnish first-year engineering students' motivational values and beliefs about the nature of mathematics
(Chapter; Bokkapittel, 2022)We report from a Nordic research project that has investigated first-year engineering students in Norway, Sweden, and Finland, and the relationships between their task performance, motivational values, and beliefs about the nature of mathematics. The present paper focuses on the covariance between their motivational values and beliefs from the perspectives of gender and nationality. The results ... -
A note about frequencies being close or amplitudes being small in frequency analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-10)In an earlier paper, an alternative method for how to solve the frequency analysis problem was offered. The object of the present paper is to bring about how to handle situations where the frequencies are close to each other or there is an amplitude that is really small. -
A Novel Technique to Mitigate the Overlap-Time Effect in Current Source Inverters
(Chapter; Bokkapittel, 2023-08-31)Generally, the current source inverter is considered more reliable than the voltage source inverter due to the presence of inductor as an energy storage element on the DC link, but a disruption in the inductor current could significantly risk its reliability. To guarantee the reliable operation of current source inverter, an overlap time must be added to the gate signals of its switches. This ensures ... -
Ny flåte og elektrifisering – Eksempel på grøne løysingar og utviklinga i dag
(Conference object; Konferansebidrag, 2020) -
Observations of sunlit N2+ aurora at high altitudes during the RENU2 flight
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-24)We present measurements of sunlit aurora during the launch of the Rocket Experiment for Neutral Upwelling 2 (RENU2) on the 13 December 2015, 07:34 UTC. The in situ auroral conditions coincide with those of sunlit aurora and were characterised by the 391.4 and 427.8 nm N<sub>2</sub> <sup>+</sup> emissions. A correlation between several auroral wavelengths, as measured by a meridian-scanning ... -
Optical water types of the Nordic Seas and adjacent areas
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-20)A new map of Jerlov's optical water types in the Nordic Seas and adjacent waters at 139 locations, as well as a table with statistical and geographical properties of the vertical attenuation coefficient of downward irradiance at 475 nm, are presented. The data analysis is based on 715 recordings at different stations, at latitudes between 54° and 82°N, and longitudes between 31°W and 49°E, obtained ... -
Optimal power flow based coordinated reactive and active power control to mitigate voltage violations in smart inverter enriched distribution network
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-30)Voltage violations are the main problem faced in distribution networks (DN) with a higher penetration of inverter-based generations (IBG). Active and reactive power control from smart inverters (SI) can mitigate such violations. Optimal power flow (OPF)-based control provides more accurate operating set points for the coordinated operation of SIs. Therefore, this paper presents a three-phase OPF-based ... -
Optimal Solutions for Underwater Capacitive Power Transfer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-09)Capacitive power transfer (CPT) has attracted attention for on-road electric vehicles, autonomous underwater vehicles, and electric ships charging applications. High power transfer capability and high efficiency are the main requirements of a CPT system. This paper proposes three possible solutions to achieve maximum efficiency, maximum power, or conjugate-matching. Each solution expresses the ... -
Path planning and reactive based control for a quadrotor with a suspended load
(Conference object; Konferansebidrag, 2021-06)This paper presents a solution to quadrotor cargo transportation, more precisely when cargo is suspended as a sling load. The challenge lies in payload position control and swing attenuation, which we approach by dividing the model into subsystems: attitude quadrotor in free flight, and translational and attitude load dynamics. We propose a solution based on reactive control, in the sense that we ... -
Path planning for UAV harvesting information from dynamical wireless sensor nodes at sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-16)A system of several wireless sensor nodes and one unmanned aerial vehicle (UAV) is considered in this research. The nodes are only floating and drifting with the sea stream. The UAV will be operating as a data mule to gather sensing information from wireless sensor nodes. Unlike prior studies, this paper addressed a realistic ocean model for the nodes movements which will be the references to the ... -
Path-following in three dimensions using quaternions for a fixed-wing UAV
(Conference object; Konferansebidrag, 2017-08-08)This paper presents a three dimensional guidance strategy for fixed-wing UAVs using quaternions. The algorithm is based on constructing two quaternions, one which makes the UAV fly towards the path and one that makes the UAV follow the path. These two quaternions are then blended together such that the path-following objective is reached. The guidance algorithm is applied to a simple kinematic model ... -
PD+ based trajectory tracking of the underactuated quadrotor platform using dual quaternions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-29)We address the problem of state feedback trajectory tracking of the underactuated quadrotor platform in the dual quaternion framework through a PD+ tracking controller. The control law negates the need of generating a desired attitude trajectory as the translational error is mapped directly onto the rotational actuators through a virtual frame. More precisely, we show uniform practical asymptotic ... -
Performance Analysis of Bidirectional Multi-Hop Vehicle-to-Vehicle Visible Light Communication
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-14)Vehicular visible light communication (VVLC) has emerged as a promising field of research, garnering considerable attention from scientists and researchers. VVLC offers a potential solution to enable connectivity and communication between travelling vehicles along the road by using their existing headlights (HLs) and taillights (TLs) as wireless transmitters and integrating photodetectors (PDs) ... -
Perspectives and reflections on teaching linear algebra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-03)This paper presents ‘expert opinions’ on what should be taught in a first-year linear algebra course at university; the aim is to gain a generic picture and general guiding principles for such a course. Drawing on a Delphi method, 14 university professors—called ‘experts’ in this study—addressed the following questions: What should be on a first-year linear algebra undergraduate course for engineering ... -
Preliminary Results on Waypoint Tracking for Spacecraft with Actuator Constraints
(Peer reviewed; Chapter; Bokkapittel, 2019-07-22)This paper presents preliminary results on how to perform waypoint tracking with spacecraft with actuator constraints. It considers a simplified spacecraft model and can be considered a deep space model, and shows how to perform waypoint tracking with only one main thruster together with full attitude control. As the spacecraft reaches close to the waypoint during a deceleration phase that makes the ... -
PSO and Kalman Filter-Based Node Motion Prediction for Data Collection from Ocean Wireless Sensors Network with UAV
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-13)In this paper, we consider a wireless sensor network of nodes at the sea surface drifting due to wind and sea currents. In our scenario an Unmanned Aerial Vehicle (UAV) will be used to gather data from the sensor nodes. The goal is to find a flyable path which is optimal in terms of sensor node energy consumption, total channel throughput between the UAV and sensor nodes, flight time for the UAV and ... -
PSO and Kalman Filter-Based Node Motion Prediction for Data Collection from Ocean Wireless Sensors Network with UAV
(Conference object; Konferansebidrag, 2021-01)In this paper, we consider a wireless sensor network of nodes at the sea surface drifting due to wind and sea currents. In our scenario an Unmanned Aerial Vehicle (UAV) will be used to gather data from the sensor nodes. The goal is to find a flyable path which is optimal in terms of sensor node energy consumption, total channel throughput between the UAV and sensor nodes, flight time for the ...
