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 N₂ ⁺ emissions. A correlation between several auroral wavelengths, as measured by a meridian-scanning ...

This paper investigates the use of the class-E inverter for power factor correction (PFC) applications. Analytical and state-space models are derived showing the class-E inverter’s capability of achieving inherent PFC operation with a constant duty cycle. The inherent PFC operation limits the controller responsibility to the regulation of the output voltage, which is key for resonant converters with ...

This study analyses the observations of a new type of small-scale aurora-like feature, which is further referred to as fragmented aurora-like emission(s) (FAEs). An all-sky camera captured these FAEs on three separate occasions in 2015 and 2017 at the Kjell Henriksen Observatory near the arctic town of Longyearbyen, Svalbard, Norway. A total of 305 FAE candidates were identified. They seem to appear ...

We address the trajectory tracking problem for a fully actuated rigid-body with unknown mass and inertia parameters and unknown disturbance forces, using an adaptive backstepping controller based on dual-quaternions. We show that the proposed controller, in closed loop with a nonlinear model of the system, renders the equilibrium points uniformly asymptotically stable. The proposed controller ...

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 ...

To augment the photovoltaic (PV) power generation conversion, a maximum power point tracking (MPPT) technique plays a very significant role. This article introduces a hybrid MPPT algorithm integrating modified invasive weed optimization (MIWO) and perturb and observe (P&O) technique under the rapid weather change and partial shading scenarios for the efficient extraction of the maximum power from ...

This thesis explores various charging standards for electric vehicles with the goal to find a standard that can be implemented in an electric maritime vessel (EMV). Combined charging system 2.0 (CCS2) is selected and the standard is explained in detail along with the necessary power electronics. Several Matlab and dSPACE simulations is made to test the charging and communication. A laboratory ...

This thesis will investigate the effects of an energy storage system incorporated into the submodules of a modular multilevel converter connected to a HVDC line. A simulation has been made to see the effects of energy storage on the transmission of power from a generator connected to the grid via a HVDC line with two MMCs connected in each end, one of which incorporates the energy storage system.

Denne rapporten presenterer design og simuleringer av en toakset solcellerigg. Denne bestpunktsporingen riggen fungerer utelukkende basert på utgangseffekten til solcellepanelet montert til det. Det bruker ikke noen solsensor til å orientere solcellepanelet. Posisjonen til solen er beregnet basert på tid og stedsinformasjon. Siden dette solpanelet vil bli montert her på UiT, Norges Arktiske Universitet, ...

This paper reports on themes that arose in an investigation of university lecturers’ views on the teaching of linear algebra. This focus on themes was the initial part of a study concentrating on four areas: What is important to teach in a first course in linear algebra? Are there teaching methods which are particularly suited for such a course? Are there tools that should/should not be used; and ...