Now showing items 111-130 of 184

    • Older People’s Attitudes and Perspectives of Welfare Technology in Norway. 

      Sanchez, Veralia Gabriela; Anker-Hansen, Camilla; Taylor, Ingrid; Eilertsen, Grethe (Peer reviewed; Journal article, 2019)
      Background: In Norway, as in other European countries, the ageing population is increasing rapidly. Governments seek to enable older people stay in their homes for as long as possible, and welfare technology (WT) has been ...
    • OMJulia: An OpenModelica API for Julia-Modelica Interaction 

      Lie, Bernt; Palanisamy, Anandhakumar; Mengist, Alachew; Buffoni, Lena; Sjölund, Martin; Asghar, Adeel; Pop, Adrian; Fritzson, Peter (Peer reviewed; Journal article, 2019)
      Modelica is an object oriented, acausal equation-based language for describing complex, hybrid dynamic models. About ten Modelica implementations exist, of which most are commercial and two are open source; the implementations ...
    • On closed loop transient response system identification 

      Dalen, Christer; Ruscio, David Luigi Di (Journal article; Peer reviewed, 2016)
      Some methods for transient closed loop step response system identification presented in the literature are reviewed. Interestingly some errors in a method published in the early 80’s where propagated into a recently published ...
    • On primary output estimation by use of secondary measurements as inputsignals in system identification 

      Ergon, Rolf (Journal article; Peer reviewed, 1999)
      In many cases, vital output variables in, e.g., industrial processes cannot be measured online. It is then of interest to estimate these primary variables from manipulated and measured inputs and the secondary output ...
    • On Tuning PI Controllers for Integrating Plus Time Delay Systems 

      Di Ruscio, David Luigi (Journal article, 2010)
      Some analytical results concerning PI controller tuning based on integrator plus time delay models are worked out and presented. A method for obtaining PI controller parameters, Kp = k , and, Ti = , which ensures a ...
    • On-Off and PI control of methane gas production of a pilot anaerobic digestion reactor 

      Haugen, Finn; Bakke, Rune; Lie, Bernt (Journal article; Peer reviewed, 2013)
      A proposed feedback control system for methane flow control of a real pilot anaerobic digestion reactor fed with dairy waste is designed and analyzed using the modified Hill model, which has previously been adapted to the ...
    • One-dimensional model of turbulent flow of non-Newtonian drilling mud in non-prismatic channels 

      Welahettige, Prasanna Kumara Welahetti; Lundberg, Joachim; Bjerketvedt, Dag; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)
      One-dimensional model of non-Newtonian turbulent flow in a non-prismatic channel is challenging due to the difficulty of accurately accounting for flow properties in the 1-D model. In this study, we model the 1-D Saint–Venant ...
    • Online acoustic chemometric monitoring of fish feed pellet velocity in a pneumatic conveying system 

      Halstensen, Maths; Ihunegbo, Felicia Nkem; Ratnayake, Chandana; Sveinsvold, Karl (Journal article; Peer reviewed, 2014-03-14)
      Fish farmers consider the cost of fish feed pellets as one of the most expensive factors in fish cultivation. Proper control of the handling and conveying systems is necessary to avoid damage and disintegration of the ...
    • Online Drilling Fluid Flowmetering in Open Channels with Ultrasonic Level Sensors using Critical Depths 

      Chhantyal, Khim; Viumdal, Håkon; Mylvaganam, Saba (Journal article; Peer reviewed, 2017)
      In drilling operations, non-Newtonian drilling fluid is continuously circulated in a closed loop. One of the ways to monitor and regulate drilling operations is by accurately measuring the flow rate of circulating drilling ...
    • Online estimation of wax deposition thickness in single-phase sub-sea pipelines based on acoustic chemometrics: A feasibility study 

      Halstensen, Maths; Arvoh, Benjamin Kaku; Amundsen, Lene; Hoffmann, Rainer (Journal article; Peer reviewed, 2012-10-25)
      Wax deposition in sub-sea oil producing pipelines is a concern to the oil producing companies. The deposition of wax in pipelines can cause serious economic implications if not monitored and controlled. Several researchers ...
    • Open Active Contour Model For Front Tracking Of Detonation Waves 

      Maharjan, Samee; Lysaker, Ola Marius; Gaathaug, André Vagner (Journal article; Peer reviewed, 2017)
      This paper presents an image processing framework for tracking the front of the detonation wave from a sequence of images. The images are captured by high speed camera during a laboratory gas explosion experiment. By ...
    • OpenHPL for Modelling the Trollheim Hydropower Plant 

      Vytvytskyi, Liubomyr; Lie, Bernt (Peer reviewed; Journal article, 2019)
      An increase of tightly integrated, renewable energy sources with highly varying production leads to a greater need for flexible hydropower plants to “balance” the intermittent production from these sources. From a systems ...
    • Optimal control strategies with nonlinear optimization for an Electric Submersible Pump lifted oil field 

      Sharma, Roshan; Glemmestad, Bjørn (Journal article; Peer reviewed, 2013)
      In an Electric Submersible Pump (ESP) lifted oil field, the ESP of each oil well should be operated inside its operating window. The total power consumed by the ESPs in the oil field should be minimized. The speed of the ...
    • Optimal design and operation of a UASB reactor for dairy cattle manure 

      Haugen, Finn; Bakke, Rune; Lie, Bernt; Hovland, Jon; Vasdal, Knut (Journal article; Peer reviewed, 2015-02-01)
      Optimal design and operation of a planned full-scale UASB reactor at a dairy farm are determined using optimization algorithms based on steady state simulations of a dynamic AD process model combined with models of the ...
    • Optimal Operation of the Peat Drying Process in Steam Tube Dryers 

      Kulakovsky, Leonid; Rosen, Victor; Sharma, Roshan; Pfeiffer, Carlos Fernando; Lie, Bernt (Conference object; Peer reviewed, 2015-11-25)
      Ukraine is an energy-dependent country and aims to reduce the import of natural gas, heat, and power in general. This implies extracting fuel from her own natural resources; one relevant and readily available energy carrier ...
    • Optimization of lift gas allocation in a gas lifted oil field as non-linear optimization problem. 

      Sharma, Roshan; Fjalestad, Kjetil; Glemmestad, Bjørn (Journal article; Peer reviewed, 2012)
      Proper allocation and distribution of lift gas is necessary for maximizing total oil production from a field with gas lifted oil wells. When the supply of the lift gas is limited, the total available gas should be optimally ...
    • Parameter and State Estimation of Large-Scale Complex Systems Using Python Tools 

      Perera, M. Anushka S.; Hauge, Tor Anders; Pfeiffer, Carlos Fernando (Journal article; Peer reviewed, 2015)
      This paper discusses the topics related to automating parameter, disturbance and state estimation analysis of large-scale complex nonlinear dynamic systems using free programming tools. For large-scale complex systems, ...
    • Parameter estimation for externally simulated thermal network models 

      Brastein, Ole Magnus; Lie, Bernt; Sharma, Roshan; Skeie, Nils-Olav (Peer reviewed; Journal article, 2019)
      Obtaining accurate dynamic models of building thermal behaviour requires a statistically solid foundation for estimating unknown parameters. This is especially important for thermal network grey-box models, since all their ...
    • Parameter estimation for grey-box models of building thermal behaviour 

      Brastein, Ole Magnus; Perera, Degurunnehalage Wathsala U.; Pfeiffer, Carlos Fernando; Skeie, Nils-Olav (Journal article; Peer reviewed, 2018)
      Good models for building thermal behaviour are an important part of developing building energy management systems that are capable of reducing energy consumption for space heating through model predictive control. A popular ...
    • PCR/PLSR optimization based on noise covariance estimation and Kalman filtering theory 

      Ergon, Rolf; Esbensen, Kim H. (Journal article; Peer reviewed, 2002)
      The theoretical connection between principal component regression (PCR) and partial least squares regression (PLSR) on one hand and Kalman filtering (KF) on the other is known from earlier work. In the present paper we ...