Viser treff 21-40 av 1014

    • Voltage Control In Smart Distribution Network With Limited Reactive Power Capacity Of Smart Inverter Using Machine Learning 

      Haider, Syed Muhammad Aizaz (Master thesis; Mastergradsoppgave, 2023-05-20)
      It is very important for consumers to have the operating voltages within the specified limit. Sometimes, this is not possible to provide by the grid operators although grid operators invest heavily in voltage regulating devices. With the integration of variable renewable energy systems in the grid, it has become more challenging for the grid companies to regulate them to provide stable voltages and ...
    • Reinforcement Learning-based Alpha-list Iterated Greedy for Production Scheduling 

      Ying, Kuo-Ching; Pourhejazy, Pourya; Cheng, Shih-Han (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-11)
      Metaheuristics can benefit from analyzing patterns and regularities in data to perform more effective searches in the solution space. In line with the emerging trend in the optimization literature, this study introduces the Reinforcement-learning-based Alpha-List Iterated Greedy (RAIG) algorithm to contribute to the advances in machine learning-based optimization, notably for solving combinatorial ...
    • Can an Industry-Led Infrastructure Development Strategy Facilitate Electric Truck Adoption? 

      Yu, Hao; Sun, Xu (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-12)
      Reverse logistics plays a critical role in sustainable development and circular economy by transforming waste into value. However, transporting large volumes of waste and recyclables generates significant carbon emissions. This paper explores an industry-led strategy for charging infrastructure development, which integrates the reverse logistics network designs with a network of charging stations ...
    • A hypothetical approach toward laser-induced high-density polyethylene pyrolysis 

      Un Nabi, Rao Adeel; Khawaja, Hassan Abbas; Liu, Yao Xiang; Yang, Chaopeng; Long, Juan; Li, Xianwang; Wang, Tie Jun (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-02)
      Laser-induced breakdown spectroscopy (LIBS) is a commonly employed technique in commercial plastic recycling for purposes including classification, sorting, identification, and elemental analysis. However, understanding the molecular-level kinetics, thermodynamic interactions, bonding cleavage, and process parameter impacts is crucial for identifying necessary modifications to enhance plastic ...
    • Performance optimization for hybrid TS/PS SWIPT UAV in cooperative NOMA IoT networks 

      Vo, Van Nhan; Dang, Viet-Hung; Tran, Hung; Tran, Duc-Dung; Chatzinotas, Symeon; Quoc, Hai Le; So-In, Chakchai; Truong, Van-Truong; Ho, Tu Dac (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-29)
      This study examines a cooperative non-orthogonal multiple access (NOMA) network utilizing an energy-constrained unmanned aerial vehicle (UAV) relay (UAVR) to expand coverage and improve network throughput. In order to provide energy to the UAVR, we consider the hybrid simultaneous wireless information and power transmission (SWIPT) method, which allows the UAVR to harvest energy from the source ...
    • New Fermatean Fuzzy Distance Metric and Its Utilization in the Assessment of Security Crises using the MCDM Technique 

      Ejegwa, Paul Augustine; Terna, Anum Manasseh; Kausar, Nasreen; Nwokoro, Chukwudi Obinna; Aydin, Nezir; Yu, Hao (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-14)
      The problem of insecurity is a global phenomenon that has several forms like terrorism, banditry, kidnappings, etc. Insecurity has taken hold in the Sub-Saharan Region of West Africa, especially in Nigeria, for over two decades. Nigeria’s security crisis is more pronounced in the Northern Region, with a new wave in the North-Central Region of Nigeria. It is herculean to assess insecurity in the ...
    • Full-scale tests of deicing with seawater 

      Sæterdal, Ane Solbakken; Sundsbø, Per-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-16)
      Sea-spray icing is one of the major hazards for small- and medium-sized vessels in polar regions. Predominant anti- and deicing measures include prevention by heeding the weather forecasts and avoiding high-risk situations, protection by enclosing exposed and high-priority areas, manual ice removal by personnel, heat tracing and surplus heat. Energy is in limited supply on vessels, and alternative ...
    • Investigating the Influence of Oil Shale Ash and Basalt Composite Fibres on the Interfacial Transition Zone in Concrete 

      Novakova, Iveta; Jhatial, Ashfaque Ahmed; Kekez, Sofija; Gjerløw, Eirik; Gulik, Volodymyr; Kannathasan, Karunamoorthy Rengasamy; Vaišnoras, Mindaugas; Krasnikovs, Andrejs (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-27)
      The interfacial transition zone (ITZ) is the weakest phase in concrete, characterised by higher porosity and being prone to microcrack formation. Additionally, the ITZ is created when dispersed fibre reinforcement is present. Although fibres improve flexural strength, they can negatively impact other properties. This research investigates the ITZ of fibre-reinforced concrete where macro-basalt fibres ...
    • A quanta-independent approach for the assessment of strategies to reduce the risk of airborne infection 

      Aganovic, Amar; Kurnitski, Jarek; Wargocki, Pawel (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-05)
      The Wells-Riley model is extensively used for retrospective and prospective modelling of the risk of airborne transmission of infection in indoor spaces. It is also used when examining the efficacy of various removal and deactivation methods for airborne infectious aerosols in the indoor environment, which is crucial when selecting the most effective infection control technologies. The problem is ...
    • Study of Heat Distribution in Railway Switch Using Resistive Heater in Cold Climate Conditions 

      Lotfi, Arefeh; Adeel, Yousuf; Virk, Muhammad Shakeel (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-11)
      The railway is an essential source of logistics and transportation in cold regions, but low temperatures and icing can be challenging for uninterrupted railway operations in these regions. Icing on railway switches is a safety hazard, and presently, one of the industry’s adaptive approaches for ice mitigation is the use of resistive heaters. This method is efficient but consumes a great amount of ...
    • ON HARDY-TYPE INEQUALITIES AS AN INTELLECTUAL ADVENTURE FOR 100 YEARS 

      Persson, Lars-Erik; Samko, Natasha Gabatsuyevna (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-02)
      We describe some chosen ideas and results for more than 100 years prehistory and history of the remarkable development concerning Hardy-type inequalities. In particular, we present a newer convexity approach, which we believe could partly have changed this development if Hardy had discovered it. In order to emphasize the current very active interest in this subject, we fnalize by presenting some ...
    • Repair Options for Corrosion-damaged Prestressed Concrete Structures 

      Sharma, Suraksha; Osmolska, Magdalena Jadwiga; Hornbostel, Karla; Bathen, Lise; Novakova, Iveta; Geiker, Mette Rica (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-05)
      Prestressing of bridges allows construction of long spanned bridges made from thin structural members with high flexural and shear capacity. Studies have shown that some of the existing prestressed bridges are not meeting their designed service life due to corrosion of the tendons. The main reasons are poor construction practices in combination with inadequate inspection and maintenance plans. ...
    • An experimental study on thermophysical properties of nano- TiO2-enhanced phase change materials for cold climate applications 

      Ravasio, Lucrezia; Hayat, Muhammad Aamer; Calay, Rajnish Kaur; Riise, Raymond; Chen, Yong (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-30)
      In high-energy-demand regions, such as the Arctic, the building sector is focused on reducing the carbon footprint and mitigating environmental impact. To achieve this, phase change materials (PCMs) are being investigated for thermal energy storage due to their high latent heat of fusion. However, their limited applications arise from poor thermal conductivity. In addressing this issue, the ...
    • Oscillatory and spectral properties of a class of fourth-order differential operators via a new Hardy-type inequality 

      Oinarov, Ryskul; Kalybay, Aigerim; Persson, Lars-Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024)
      In this paper, we study oscillatory properties of a fourth-order differential equation and spectral properties of a corresponding differential operator. These properties are established by f irst proving a new second-order Hardy-type inequality, where the weights are the coefficients of the equation and the operator. This new inequality, in its turn, is established for functions satisfying certain ...
    • Weighted estimates of commutators of singular operators in generalized Morrey spaces beyond Muckenhoupt range and applications 

      Samko, Natasha Gabatsuyevna (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-30)
      For a certain class of radial weights, we prove weighted norm estimates for commutators with BMO coefficients of singular operators in local generalized Morrey spaces. As a consequence of these estimates, we obtain norm inequalities for such commutators in the generalized Stummel-Morrey spaces. We also discuss a.e. well-posedness of singular operators and their commutators on weighted generalized ...
    • Two-agent proportionate flowshop scheduling with deadlines: polynomial-time optimization algorithms 

      Ying, Kuo-ching; Pourhejazy, Pourya; Sung, Chuan-En (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-21)
      Volatility in the supply chain of critical products, notably the vaccine shortage during the pandemic, influences livelihoods and may lead to significant delays and long waiting times. Considering the capital- and time-intensive nature of capacity expansion plans, strategic oper ational production decisions are required best to address the supply-demand mismatches given the limited production ...
    • Mechanical Properties of MiniBars™ Basalt Fiber-Reinforced Geopolymer Composites 

      Furtos, Gabriel; Prodan, Doina; Sarosi, Codruta; Moldovan, Marioara; Korniejenko, Kinga; Miller, Leonard; Fiala, Lukáš; Novakova, Iveta (Journal article; Tidsskriftartikkel, 2024-01-02)
      Fly ash-based geopolymers represent a new material, which can be considered an alternative to ordinary Portland cement. MiniBars™ are basalt fiber composites, and they were used to reinforce the geopolymer matrix for the creation of unidirectional MiniBars™ reinforced geopolymer composites (MiniBars™ FRBCs). New materials were obtained by incorporating variable amount of MiniBars™ (0, 12.5, 25, 50, ...
    • On the Fidelity of RANS-Based Turbulence Models in Modeling the Laminar Separation Bubble and Ice-Induced Separation Bubble at Low Reynolds Numbers on Unmanned Aerial Vehicle Airfoil 

      Muhammed, Manaf; Virk, Muhammad Shakeel (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-09)
      The operational regime of Unmanned Aerial Vehicles (UAVs) is distinguished by the dominance of laminar flow and the flow field is characterized by the appearance of Laminar Separation Bubbles (LSBs). Ice accretion on the leading side of the airfoil leads to the formation of an Ice-induced Separation Bubble (ISB). These separation bubbles have a considerable influence on the pressure, heat flux, and ...
    • Teaching Linear Algebra to Engineering Students in Two Different Educational Settings: Design and Learning Outcomes 

      Rensaa, Ragnhild Johanne (Journal article; Tidsskriftartikkel, 2024-02-16)
      The present paper holds a twofold perspective on a new teaching format in a linear algebra course given to engineering students. The design resembles the flipped classroom, but with various adjustments. The first part highlights the basis on which the design was built, both research results and practical issues, but also the implementation of the teaching. It did not proceed quite as expected. The ...
    • An exploration of the concept of constrained improvement in data envelopment analysis 

      Arabjazi, Nasim; Pourhejazy, Pourya; Rostamy-Malkhalifeh, Mohsen (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-31)
      Constrained improvement refers to regulating rivalry between companies in a particular industry by defining a framework or an evaluation mechanism. Such a mechanism results in a more equitable and healthy competitive environment. The primary motivation is that the best-performing players in a particular industry improve their performance such that the rest of the contenders remain competitive. ...