Now showing items 21-40 of 280

    • A Comparison of Two Location Models in Optimizing the Decision-making on the Relocation Problem of Post Offices at Narvik, Norway 

      Yu, Hao; Solvang, Wei Deng (Peer reviewed; Book; Chapter, 2018)
      Since 2013, the postal service provider in Norway: Posten has implemented a new strategic plan to close their large post offices across the country for improving the cost and operational efficiency. Instead, with the cooperation with large retailers, the local postal service is provided at the Posten sub-branches at some supermarkets. In this paper, an optimization problem for relocating the post ...
    • A comparison of the energy consumption for CO2 compression process alternatives 

      Jackson, Steven; Brodal, Eivind (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
      The efficient transportation of large volumes of CO2 generally requires pipelines that will operate above the critical pressure of CO2. Since most capture processes release CO2 at low pressure, compression of CO2 from the point of capture to pipeline will generally be required. The compression duty can be achieved using conventional multi-stage compressors or using newer shockwave type compressors. ...
    • Quaternion Path-Following in Three Dimensions for a Fixed-Wing UAV Using Quaternion Blending 

      Andersen, Tom Stian; Kristiansen, Raymond (Peer reviewed; Book; Chapter, 2018-10-29)
      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 ...
    • Studies of some Operators of Harmonic Analysis in certain Function Spaces with Applications to PDEs 

      Lundberg, Staffan (Doctoral thesis; Doktorgradsavhandling, 2018-12-05)
      The study in this PhD thesis aims at development of certain mathematical methods used in applications, in particular, in the study of regularity properties of solutions in various mathematical models described by Partial Differential Equations (PDEs). To this end, we study various operators of harmonic analysis in certain function spaces, since solutions to many PDEs may be expressed in terms of ...
    • Incorporating flexible capacity in the planning of a multi-product multi-echelon sustainable reverse logistics network under uncertainty 

      Yu, Hao; Solvang, Wei Deng (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-05)
      With the focus on sustainable development, the value recovery from End-of-Life (EOL) and End-of-Use (EOU) products has been given considerable attention by the whole society. Reverse logistics is the process for value recovery and re-creation through a series of activities, i.e., repair, remanufacturing, recycling and energy recovery. However, due to the stochastic reverse product flow, unstable ...
    • A Reliable Modular Based PV-Battery Hybrid System with Peak Shaving Capability 

      Sohail, Umer; Nademi, Hamed; Norum, Lars Einar (Peer reviewed; Chapter, 2018)
      The driving factors in emerging photovoltaic (PV) systems and battery-energy-storage systems (BESS) are highly scalable feature, modular and flexible structures with superior transformerless performance. The feasibility of Modular Multilevel Converter (MMC) to operate without overall DC-link allows the integration of PV generators and battery strings with its submodules (SMs), whereas each SM acts ...
    • Cascaded Model Predictive Control of Grid Connected Converter with LCL Filter 

      Hoff, Bjarte (Peer reviewed; Book; Chapter, 2018-12-31)
      This paper presents a control strategy for grid connected voltage source converters with LCL filter, based on a cascade of two model predictive controllers (MPC). Despite the attention MPC has received in the research community over the last years, there are still raised question about what advantages such control methods can offer, compared to existing established control strategies. The cascaded ...
    • Human-Robot Collaboration: Task Sharing Through Virtual Reality 

      Shu, Beibei; Sziebig, Gabor; Pieskä, Sakari (Peer reviewed; Book; Chapter, 2018-12-31)
      Collaborative Robots provide many possibilities, when it comes to Human-Robot Collaboration. Until now, these approaches are usually custom made, sensor-integrated solutions, where the robot's safety controller ensures the safety of the human worker. These solutions are according to today's rules and standards. We propose to extend these solutions with including Virtual Realty as a sensor and to ...
    • 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 ...
    • Introduction of cyber-physical system in robotized press-brake line for metal industry 

      Shu, Beibei; Sziebig, Gabor; Solvang, Bjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-11)
      Bin picking is a typical work, which is easy to automate up to a given complexity of the work-piece dimensions. In case of casted work-pieces, the dimensions are most of the time not accurate enough for an industrial robot to be able to pick it up without additional sensors/intelligence. In this paper we introduce a cyber-physical system, where all sensors, actuators, machines and industrial robot ...
    • Curvature Continuous Path Generation for UAVs based on Generalized Expo-Rational B-Splines 

      Andersen, Tom Stian; Bouzidi, Ghada; Kristiansen, Raymond (Peer reviewed; Book; Chapter, 2018)
      This paper proposes a new path-planning algorithm based on GERBS to generate curvature continuous paths. The algorithm blends between a set of local curves generating a global smooth path which also interpolates the midpoint of the curves. Numerical examples are provided which demonstrates the potential of the proposed algorithm.
    • Dual-quaternion backstepping control for a fully-actuated rigid-body 

      Andersen, Tom Stian; Johansen, Tor-Aleksander; Kristiansen, Raymond (Peer reviewed; Book; Chapter, 2018-08-16)
      In this paper dual-quaternions are used to model a fully actuated rigid-body. A backstepping-controller that solves the trajectory tracking problem is derived and proved to provide uniform asymptotical stabilization of the error dynamics. Numerical simulations are provided where the controller is compared to existing dual-quaternion tracking controllers and it is shown to have similar performance.
    • Geometric Construction of Some Lehmer Means 

      Høibakk, Ralph; Lukkassen, Dag; Meidell, Annette; Persson, Lars Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-14)
      The main aim of this paper is to contribute to the recently initiated research concerning geometric constructions of means, where the variables are appearing as line segments. The present study shows that all Lehmer means of two variables for integer power k and for k = m 2 , where m is an integer, can be geometrically constructed, that Lehmer means for power k = 0,1 and 2 can be geometrically ...
    • On Context, Issues, and Pitfalls of Expert Judgement Process in Risk Assessment of Arctic Offshore Installations and Operations 

      Naseri, Masoud; Barabadi, Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      Decisions to be made in the Arctic offshore operations rely extensively on risk assessment outputs, which require a great deal of historical data and information. However, at the current stage of operating in the Arctic offshore – compared to normal-climate regions – such data is scarce due to the limited industrial activities to date. Lack of data on the probability of the occurrence of an unwanted ...
    • A NEW GENERALIZATION OF BOAS THEOREM FOR SOME LORENTZ SPACES Λq(ω) 

      Kopezhanova, Aigerim; Nursultanov, Erlan; Persson, Lars Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      Let Λq( ω ), q > 0, denote the Lorentz space equipped with the (quasi) norm [<i>MATHEMATICAL FORMULA</I>] for a function f on [0,1] and with ω positive and equipped with some additional growth properties. A generalization of Boas theorem in the form of a two-sided inequality is obtained in the case of both general regular system [<i>MATHEMATICAL FORMULA</I>] and generalized Lorentz Λq( ω ) spaces
    • Multi-dimensional Hardy type inequalities in Hölder spaces 

      Burtseva, Evgeniya; Lundberg, Staffan; Persson, Lars Erik; Samko, Natasha (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      Most Hardy type inequalities concern boundedness of the Hardy type operators in Lebesgue spaces. In this paper we prove some new multi-dimensional Hardy type inequalities in Hölder spaces.
    • Two-sided estimates of the Lebesgue constants with respect to Vilenkin systems and applications 

      Blahota, Istvan; Persson, Lars Erik; Tephnadze, G (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-03-13)
      In this paper, we derive two-sided estimates of the Lebesgue constants for bounded Vilenkin systems, we also present some applications of importance, e.g., we obtain a characterization for the boundedness of a subsequence of partial sums with respect to Vilenkin–Fourier series of H 1 martingales in terms of n's variation. The conditions given in this paper are in a sense necessary and sufficient.
    • Some inequalities for Cesàro means of double Vilenkin-Fourier series 

      Tephnadze, G; Persson, Lars Erik (Journal article; Peer reviewed; Tidsskriftartikkel, 2018-12-19)
      In this paper, we state and prove some new inequalities related to the rate of Lp approximation by Cesàro means of the quadratic partial sums of double Vilenkin–Fourier series of functions from Lp.
    • Sustainable supply chain management for blue economics in Northern Norway 

      Sandåker, Anders (Master thesis; Mastergradsoppgave, 2018-06-01)
      In the first part of thesis, there was conducted a literature review of production and the supply chain with regards to fish farming, existing technologies, together with the potential of alternative digital technology. In the second part, a case study of a relevant manufacturer who is involved in all the aspects of the value chain was carried out to gain insight into relevant supply chain ...
    • Logistic Service at Ports in Northern Norway. Case Study of the Port of Narvik 

      Knapskog, Knut Arthur (Master thesis; Mastergradsoppgave, 2018-06-01)
      This thesis is a part of the Master of Science degree in Industrial Engineering at the University of Tromsø – The arctic University of Norway, Campus Narvik. The aim of this thesis is to improve the logistic service and increase the competitiveness of ports in Northern Norway in order to attract more port users. A literature review on the topics of logistics in seaports is presented, along with an ...