Viser treff 859-878 av 914

    • UA and pinch point temperature difference modeling — Finding the best heat exchanger schemes 

      Brodal, Eivind; Jackson, Steven; Hailu, Getu (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-28)
      Process models using simplified heat exchanger (HE) models are often analyzed using methods based on derivatives or optimization procedures, where even small numerical errors can cause algorithms to fail. This article explores the use of numerical approximations for calculating pinch temperature and UA-value, including novel high-order polynomial methods using equidistant and Chebyshev grids. The ...
    • Ubemannede flaksende mikrofly 

      Oland, Espen (Journal article; Tidsskriftartikkel, 2013)
    • Under Seawater Capacitive Power Transfer for Maritime Charging Applications 

      Al-Sallami, Hussein Mahdi Yaseen; Hattori, Reiji; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2023-09-12)
      Underwater capacitive power transfer (CPT) can provide an inexpensive and light electric charging solution with good misalignment tolerance for unmanned maritime vehicles. This paper investigates the effect of the changing of the frequency and the distance on the power transfer and overall efficiency of the underwater CPT system, considering the dielectric losses of the medium. It also proposes and ...
    • Underactuated Control of Quadrotors with Collision Avoidance 

      Oland, Espen; Andersen, Tom Stian; Kristiansen, Raymond (Journal article; Peer reviewed; Tidsskriftartikkel, 2013)
      In this paper a saturated controller is derived that solves the translational control problem for underactuated quadrotors. The controller is applied to multiple quadrotors during a formation reconfiguration where the quadrotors move from an initial position to a desired position. The null-space-based behavioral control method is a popular method for avoiding collisions between mobile agents, and ...
    • Underactuated Waypoint Tracking of a Fixed-Wing UAV 

      Oland, Espen; Schlanbusch, Rune; Kristiansen, Raymond (Journal article; Peer reviewed; Tidsskriftartikkel, 2013)
      In this paper a new method of performing waypoint tracking is shown for underactuated fixed-wing UAVs. The position error can be mapped onto the desired axis using a desired rotation matrix, while the velocity error can be mapped to the desired axis using a desired angular velocity. With all errors defined along one axis, the tracking problem is easily solved using only one thruster. A velocity ...
    • Understanding Physical Properties of Fresh Water and Marine Ice using Multiphysics Modelling and Infrared Thermography 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2023)
      Ice has unique physical properties, which tend to vary depending on how, where, and when it forms. In the presented work, we looked deeper into various physical properties of ice. In one of the studies, we focused on studying the ice adhesion on two types of polymers; polyurethane (PU) and polyvinyl-chloride (PVC). It revealed interesting behaviors with a viable potential for roads/highways coated ...
    • Underwater Inductive Power Transfer with Wireless Charging Applications 

      Monari, Lydiah Mitchelle (Master thesis; Mastergradsoppgave, 2022-05-16)
      Underwater wireless power transfer (UWPT) has become an area of great interest due to the advancement of autonomous underwater vehicles (AUVs) and electic boats. This paper seeks to investigate the variation of the coupling coefficient and power transfer in air versus in seawater. The design is based on a class E converter as it can achieve soft-switching inherently. I made the transmitter and ...
    • Use of digital technology to follow the consequences of a warming Arctic climate 

      Myrmel, Liv Brita Hætta; Gudmestad, Ove Tobias (Journal article; Tidsskriftartikkel; Peer reviewed, 2021)
      The rapid warming climate is causing the Arctic ice to retreat and the permafrost to melt. These visible manifestations of the ongoing climate change are few of many environmental and societal changes that take place in the Arctic. The acceleration of digitalization and implementation of digital technology bring new opportunities to follow the consequences of the warmer arctic climate, but also ...
    • User-Friendly MES Interfaces: Recommendations for an AI-Based Chatbot Assistance in Industry 4.0 Shop Floors 

      Mantravadi, Soujanya; Jansson, Andreas Dyrøy; Møller, Charles (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-04)
      The purpose of this paper is to study an Industry 4.0 scenario of ‘technical assistance’ and use manufacturing execution systems (MES) to address the need for easy information extraction on the shop floor. We identify specific requirements for a user-friendly MES interface to develop (and test) an approach for technical assistance and introduce a chatbot with a prediction system as an interface layer ...
    • Using Deep Learning Methods for Segmenting Polar Mesospheric Summer Echoes 

      Domben, Erik Seip; Sharma, Puneet; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-31)
      Polar mesospheric summer echoes (PMSE) are radar echoes that are observed in the mesosphere during the arctic summer months in the polar regions. By studying PMSE, researchers can gain insights into physical and chemical processes that occur in the upper atmosphere—specifically, in the 80 to 90 km altitude range. In this paper, we employ fully convolutional networks such as UNET and UNET++ for ...
    • Using Deep Learning Methods to Monitor Non-Observable States in a Building 

      Tangrand, Kristoffer; Bremdal, Bernt Arild (Conference object; Konferansebidrag, 2020-02-06)
      This paper presents results from ongoing research with a goal to use a combination of time series from non-intrusive ambient sensors and deep recurrent neural networks to predict room usage at a university campus. Training data was created by collecting measurements from ambient sensors measuring room CO2, humidity, temperature, light, motion and sound, while the ground-truth counts was created ...
    • Using Deep Learning to Predict the Amount of Chemicals Applied on the Wheel Track for Winter Road Maintenance 

      Hatamzad, Mahshid; Polanco Pinerez, Geanette Cleotilde; Casselgren, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-30)
      The decade of big data has emerged in recent years, which has led to entering the era of intelligent transportation. One of the main challenges to deploying intelligent transportation is dealing with winter roads in cold climate countries. Different operations can be used to protect the road from ice and snow, such as spreading chemicals (here salt) on the road surface. Using salt for de-icing and ...
    • Using Infrared Thermography and Multiphysics Modelling to Investigate Ice 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2022)
    • Using Light Weight Electric Vehicles for V2G services in the Arctic 

      Dadman, Shayan; Bremdal, Bernt Arild (Chapter; Bokkapittel, 2023-06)
      The proposed paper documents research carried out in the Smart Charge project. This project has investigated the use of electric snowmobiles for V2G purposes. Electric snowmobiles and ATVs have been introduced in remote areas in the Arctic to replace the fossil fuelled vehicles that dominate today. Electric versions of these can add extra loads to the local electricity grid. But they can also be ...
    • Using Mutual Charge Scheme to Measure Salinity of Ice 

      Mughal, Umair Najeeb; Nikumbh, Bhushan (Journal article; Peer reviewed; Tidsskriftartikkel, 2015)
      For offshore measurements in Cold Regions, salinity of ice is also a critical parameter (together with many other parameterssuchasicingtype,load,icingrateandmeltingrate)to be identified in order to optimize the performance of anti/de icing systems. Although there are some available sensory solutions in the market to measure real time salinity levels of water, however there are still not many real ...
    • Using Slightly Imbalanced Binary Classification to Predict the Efficiency of Winter Road Maintenance 

      Hatamzad, Mahshid; Polanco Pinerez, Geanette; Cesselgren, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-30)
      The prediction of efficiency scores for winter road maintenance (WRM) is a challenging and serious issue in countries with cold climates. While effective and efficient WRM is a key contributor to maximizing road transportation safety and minimizing costs and environmental impacts, it has not yet been included in intelligent prediction methods. Therefore, this study aims to design a WRM ...
    • Utilizing fuel cell technology for Dubai Roads and Transport Authority (RTA) 

      Al-Mahadin, Aziz; Mustafa, Mohamad (Peer reviewed; Chapter, 2018-06-11)
      The need for developing environmentally friendly and sustainable energy sources is globally evident. This is due to two main reasons: Fossil fuels will continue to supply energy demands for only a few more decades and the amount of pollution generated due to fossil fuels is exceeding acceptable limits. One very promising clean energy converter is the fuel cell (FC). Fuel cells have the ability to ...
    • Utilizing Local Flexibility Resources to Mitigate Grid Challenges at Electric Vehicle Charging Stations 

      Ilieva, Iliana; Bremdal, Bernt Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-12)
      Charging of electric vehicles (EVs) on a large scale can cause problems for the grid. Utilizing local flexibility resources, such as smart charging, stationary battery, vehicle-to-grid applications, and local generation can be an efficient way to contain the grid challenges and mitigate the need for grid reinforcement. Focusing on the INSPIRIA charging station located in Norway, this paper investigates ...
    • Utnyttelse av digitale data i byggefasen for småhusentreprenører 

      Pedersen, Kristian; Lindberg, Emil (Master thesis; Mastergradsoppgave, 2022-05-14)
      Digital transformasjon i bygge-, anleggs- og eiendomsnæringen (BAE-næringen) sees på som en felles løsning for å motvirke produktivitetsnedgangen i bransjen. Utveksling av data mellom aktører, høy automatiseringsgrad og utnyttelse av data og trekkes frem som hovedpunkter i den digitale transformasjonen. Bygningsinformasjonsmodellering (BIM) har en sentral rolle i dette og beskrives som et nav i ...
    • Utnytting av energi i vannforsyning for oppvarming av større bygg 

      Chen, Liguo (Master thesis; Mastergradsoppgave, 2017-06-08)
      Det anbefales et varmepumpeanlegg med tre sammenkoblete varmepumper som benytter kommunes backup drikkevannsforsyning som varmekilde. Anlegget kan levere 262 kW varmeeffekt til Salangen bo- og eldresenter og Vasshaug barnehage. Økonomisk vurdering viser at prosjektet har en positiv nåverdi på 3,8 mil. kroner og 2,9 år inntjeningstid.