Sökning: "Semi-empirical"

Visar resultat 1 - 5 av 99 avhandlingar innehållade ordet Semi-empirical.

  1. 1. Data-driven Ship Performance Models - - Emphasis on Energy Efficiency and Fatigue Safety

    Författare :Xiao Lang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semi-empirical; energy efficiency; fatigue assessment; grey-box; full-scale measurements; speed-power relationship; added resistance due to waves; ship performance; machine learning;

    Sammanfattning : Due to digitalization in the maritime industry, a huge amount of ship operation-related data has been collected. The main objective of this thesis is to exploit machine learning/big data analytics to build data-driven ship performance models, focusing on speed-power relationship modeling, and fatigue accumulation assessment during a ship’s operation at sea. LÄS MER

  3. 2. Developing semi-empirical ab initio based potentials in materials modeling

    Författare :Jie Fu; Anatoly Belonoshko; Michael Odelius; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics;

    Sammanfattning : Ab initiocalculation based on density function theory (DFT) is an accu-rate and efficient method for modelling material properties. It is performedby solving the Shrödinger equations with a few assumptions to obtain thephysical properties of the system. It is very computational demanding whendealing with large systems or long-time simulations. LÄS MER

  4. 3. On two semi-empirical methods based on zero differential overlap

    Författare :Germund Höjer; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  5. 4. Solid Fuel Conversion in Dual Fluidized Bed Gasification - Modelling and Experiments

    Författare :Louise Lundberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dual fluidized bed gasification; fuel mixing; biomass; semi-empirical modelling; char gasification rate; fuel conversion; active bed material; char reactivity;

    Sammanfattning : Dual fluidized bed gasification (DFBG) is the initial step towards the transformation of ligno-cellulosic materials into a raw gas, which can be further upgraded into transportation fuels, such as substitute natural gas, Fischer-Tropsch diesel, dimethyl ether, and methanol. DFBG units can be operated in two distinctly different ways, depending on whether the main product is a gas (to be refined into a transportation fuel) or heat and power (with gas as a by-product). LÄS MER

  7. 5. Modelling of Battery Electrolyte Interactions

    Författare :Gustav Åvall; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lithium-ion batteries; semi-empirical Methods.; sodium-ion batteries; ab initio molecular dynamics; electrolytes; density functional theory;

    Sammanfattning : The rechargeable lithium-ion battery (LIB), powering our portable electronics, has transformed our everyday lives. Even though the success of the LIB there is a need for next generation batteries, due to a lack of abundant lithium and a need for greater performance and sustainable chemistries, in order to move towards a sustainable society with applications such as hybrid and electrical vehicles (EVs) and large scale energy storage for solar and wind power. LÄS MER