Blar i tittel Fakultet for ingeniørvitenskap og teknologi

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    • Asymptotic Behaviour of Ground States for Mixtures of Ferromagnetic and Antiferromagnetic Interactions in a Dilute Regime 

      Braides, Andrea; Causin, Andrea; Piatnitski, Andrey; Solci, Margherita (Journal article; Peer reviewed, 2018-04-30)
      We consider randomly distributed mixtures of bonds of ferromagnetic and antiferromagnetic type in a two-dimensional square lattice with probability 1−p 1−p and p, respectively, according to an i.i.d. random variable. We study minimizers of the corresponding nearest-neighbour spin energy on large domains in Z 2 Z2 . We prove that there exists p 0 p0 such that for p≤ p 0 p≤p0 such ...

    • Asymptotics of a spectral-sieve problem 

      Amirat, Youcef; Bodart, Olivier; Chechkin, Gregory; Piatnitski, Andrey (Peer reviewed; Journal article; Tidsskriftsartikkel, 2015-11-18)
      In a bounded domain with a thin periodically punctured interface we study the limit behavior of the bottom of spectrum for a Steklov type spectral problem, the Steklov boundary condition being imposed on the perforation surface. For a certain range of parameters we construct the effective spectral problem and justify the convergence of eigenpairs.

    • Asymptotics of fundamental solutions for time fractional equations with convolution kernels 

      Kondratiev, Yuri; Piatnitski, Andrey; Zhizhina, Elena (Journal article; Peer reviewed, 2020-09-11)
      The paper deals with the large time asymptotic of the fundamental solution for a time fractional evolution equation with a convolution type operator. In this equation we use a Caputo time derivative of order α ∈ (0, 1), and assume that the convolution kernel of the spatial operator is symmetric, integrable and shows a super-exponential decay at infinity. Under these assumptions we describe the ...

    • Atmospheric Contamination of Coastal Cities by the Exhaust Emissions of Docked Marine Vessels: The Case of Tromsø 

      Zubiaga, Asier; Madsen, Synne; Khawaja, Hassan; Boiger, Gernot (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-03)
      Docked ships are a source of contamination for the city while they keep their engine working. Plume emissions from large boats can carry a number of pollutants to nearby cities causing a detrimental effect on the life quality and health of local citizens and ecosystems. A computational fluid dynamics model of the harbour area of Tromsø has been built in order to model the deposition of CO2 gas emitted ...

    • Atmospheric Contamination of Coastal Cities by the Exhaust Emissions of Docked Marine Vessels: the case of Tromsø 

      Zubiaga, Asier; Madsen, Synne; Khawaja, Hassan; Boiger, Gernot (Journal article; Tidsskriftartikkel, 2021-08-04)
      Docked ships are a source of contamination for the city while they keep their engine working. Plumes emissions from large boats can carry a number of pollutants to the nearby cities causing a detrimental effect on the life quality and health of local citizens and ecosystems. A computational fluid dynamics model of the harbour area of Tromsø has been built in order to model the deposition of CO2 gas ...

    • Atmospheric Ice Accretion Measurement Techniques 

      Virk, Muhammad Shakeel; Mustafa, Mohamad Y; Hamdan, Qusai-Al (Journal article; Tidsskriftartikkel; Peer reviewed, 2011-09-30)
      Atmospheric icing on structures has proven to be an area of concern in many cold climate geographical regions like arctic and alpine. Difficulties encountered by the communication, construction and power industries in these areas are the subject of intense investigations for researchers from decades. Three main methods of investigation are generally employed by researchers to study atmospheric ice ...

    • Atmospheric ice accretion on non rotating vertical circular cyliner 

      Virk, Muhammad Shakeel; Mughal, Umair Najeeb; Polanco, Geanette (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-22)
      Study of atmospheric ice accretion on a non-rotating vertical circular cylindrical object was carried out at dry and wet ice conditions. Both numerical and experimental techniques were used during this study. 3D numerical study was carried out using computational fluid dynamics based approach, whereas experimental study was carried out at Cryospheric Environmental Simulator ‘CES’ in Shinjo, Japan. ...

    • Atmospheric Ice Accretion on Railway Overhead Powerline Conductors- A Numerical Case Study 

      Lotfi, Arefeh; Virk, Muhammad Shakeel; Pettersen, Jan-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-16)
      Ice accretion on railway overhead contact wires/conductors can cause various critical operational and safety issues such as overloading, arc formation, mass imbalance, and wire galloping. The focus of this multiphase numerical study is to understand and analyze the ice accretion physics on railway overhead powerline conductors at various operating conditions. In this regard, two different ...

    • Atmospheric ice monitoring system operation at Remote locations in cold region 

      Virk, Muhammad Shakeel; Rashid, Taimur; Mustafa, Mohamad Y (Journal article; Peer reviewed; Tidsskriftartikkel, 2013)
      The problems encountered in installation, maintenance and operations of equipment in the cold climate regions are far more complicated than others. The contributing factors and problems that can affect the system operation and performance should be identified, assessed and focused within well-defined parameters before its installation in cold climate regions. The harsh cold environment, could not ...

    • Atmospheric icing on wind turbines : Modeling and consequences for energy production 

      Homola, Matthew Carl (Doctoral thesis; Doktorgradsavhandling, 2011)

    • Atmospheric Icing Sensors - Capacitive Techniques 

      Mughal, Umair Najeeb; Virk, Muhammad Shakeel (Peer reviewed; Journal article; Tidsskriftsartikkel, 2013-01-22)
      The application of capacitive sensing technique is widely distributed in different physical domains primarily because of the diversity in dielectric permittivity and due to its minimum loading error and inertial effects. Atmospheric ice is a complex mixture of water, ice and air which is reflected in its complex dielectric constant. There are many existing atmospheric icing sensors but only few are ...

    • Atomized feedback, an approach to automatic formative assessment 

      Steen, Arild; Movik, Hans Richard (Peer reviewed; Chapter, 2017-11)
      In this article, we describe an approach to give automatic formative evaluation by atomizing the feedback. The mechanics in this approach is a large number of multiple-choice tests. The multiplechoice tests are used as voluntary assignments and gives controlled progression by releasing the tests in an order. Instruction is in the spirit of flipped classroom with short video lectures accompanied by ...

    • Attitude Determination and Control System for Satellites in Elliptical Orbits - a Complete Solution 

      Oland, Espen (Konferansebidrag; Conference object, 2017-08-08)
      This paper presents a complete solution to the problem of attitude determination and control for satellites in elliptical orbits. Specifically, it shows how to create the orbital mechanics, account for perturbing gravity torques, create a nonlinear PD+ attitude controller, map the control signal to desired thrust firings, implement magnetic field and Sun vector models, and how to implement a Madgwick ...

    • Augmented Reality Application for Training in Maritime Operations. A Proof of Concept AR Application Developed for Microsoft HoloLens 

      Xue, Hui (Master thesis; Mastergradsoppgave, 2017-06-27)
      Augmented reality (AR) is an advanced technology that integrates augmentations with the real world. This technology has been used to provide training and education along with other purposes. This work has been focused on enriching the learning experience of the maritime trainee by applying AR technology. In this work, a proof of concept AR application (App) is developed for the training of the ...

    • Automated multi-rotor draft survey of large vessels 

      Usman, Muhammad (Master thesis; Mastergradsoppgave, 2022-05-16)
      In maritime sector draft survey has a significant importance as it is used to determine many important factors used in maritime transportation. Draft is the vertical displacement from the bottom of the keel (the bottom-most element of a vessel) to the water line (the line of meeting point of hull and the water surface). It is used to measure the minimum water depth for safe navigation of vessel and ...

    • Automated Tugboat Assisted Docking of Large Vessels 

      Abdullah, Muhammad Zaeem (Master thesis; Mastergradsoppgave, 2022-05-15)
      The main research aspect behind this project was the problem in docking the ship to the port with limited space and resources available, causing number of onsite accidents and loss of resources. The main objective is to increase safety on ports, reduce pollution and increase fuel efficiency, also reduce the docking time for the vessels, which can be achieved by developing an autonomous docking system ...

    • Automatic Generation of Custom Image Recognition Models 

      Hanssen, Magnus Fredheim (Master thesis; Mastergradsoppgave, 2022-05-15)
      In this thesis, we examine the viability of training a convolutional neural network using synthetic data. The cnn is used for image recognition in an rms. We create a program that can render 3D models from STL files as images with varied backgrounds. The process of creating and training an image recognition model is also automated. Lastly, the model is used for image recognition. The report ...

    • Automatic verification of UI tests 

      Hagerup, Christopher Kragebøl (Master thesis; Mastergradsoppgave, 2019-06-28)
      The purpose of this thesis is to investigate whether or not it is possible to perform automatic verification of UI Tests using Neural Networks. The problem being looked at is variance tied to the operating system, graphics card, or other hardware. This can cause false positives during UI testing, and thus we wanted to find a solution that could learn to ignore this, while still verifying the result. ...

    • Autonomous Inspection of the International Space Station 

      Oland, Espen (Konferansebidrag; Conference object, 2017-09-18)
      This paper presents a solution to autonomous inspection of the international space station using a rigid spacecraft. Specifically, the paper presents the orbital mechanics, formation dynamics as well as rotational dynamics required to control the spacecraft relative to the space station, and then presents two PD+ controllers enabling a spacecraft to track a series of waypoints while pointing a sensor ...

    • Å studere effekt av isolasjonsmaterialet[s] posisjon i en husvegg 

      Anwar, Mohammad (Master thesis; Mastergradsoppgave, 2016-11-01)
      Rapporten tar for seg en eksperimentelle analyse i for bindelse med varmetransports gjennomyttervegger. Det teoretiske grunnlaget tar for seg Energitap gjennomvegger, varmeoverføringsfaktorer og fordeling i yttervegger. Numeriske beregninger og Simuleringer er utført for å studere virkninger av isolasjonsmaterialer i varmt og kaldforhold.