Sökning: "Spatial Refinement"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden Spatial Refinement.

  1. 1. Development of Effective Algorithm for Coupled Thermal-Hydraulics – Neutron-Kinetics Analysis of Reactivity Transient

    Författare :Joanna Peltonen; Tomas Lefvert; Paolo Vinai; KTH; []
    Nyckelord :Light Water Reactor; BWR; RELAP5; PARCS; Coupling TH NK; Mapping; Spatial Refinement; Turbine Trip; Feedwater Transient; Control Rod Drop; Reactor Stability;

    Sammanfattning : Analyses of nuclear reactor safety have increasingly required coupling of full three dimensional neutron kinetics (NK) core models with system transient thermal-hydraulics (TH) codes. To produce results within a reasonable computing time, the coupled codes use different spatial description of the reactor core. LÄS MER

  3. 2. Effective Spatial Mapping for Coupled Code Analysis of Thermal–Hydraulics/Neutron–Kinetics of Boiling Water Reactors

    Författare :Joanna Peltonen; Weimin Ma; Maria Avramova; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boiling Water Reactor; RELAP5; TRACE; PARCS; Coupled TH NK analysis; Spatial Mapping; Turbine Trip; Feedwater Transient; Control Rod Drop; Reactor Stability; Hierarchical Clustering; kokvattenreaktor; reaktoranalys; RELAP5; TRACE; PARCS; TH NK analys; turbin tripp; matarvatten transient; fallande styrstav; reaktor stabilitet; hierarkisk klustringsmetodik; SRA - Energy; SRA - Energi;

    Sammanfattning : Analyses of nuclear reactor safety have increasingly required coupling of full three dimensional neutron kinetics (NK) core models with system transient thermal–hydraulics (TH) codes.  In order to produce results within a reasonable computing time, the coupled codes use two different spatial description of the reactor core. LÄS MER

  4. 3. Adaptive Solvers for High-Dimensional PDE Problems on Clusters of Multicore Processors

    Författare :Magnus Grandin; Sverker Holmgren; Michael Thuné; Michael Bader; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adaptive mesh refinement; anisotropic refinement; exponential integrators; Lanczos algorithm; hybrid parallelization; time-dependent Schrödinger equation; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Accurate numerical solution of time-dependent, high-dimensional partial differential equations (PDEs) usually requires efficient numerical techniques and massive-scale parallel computing. In this thesis, we implement and evaluate discretization schemes suited for PDEs of higher dimensionality, focusing on high order of accuracy and low computational cost. LÄS MER

  5. 4. Robust Stream Reasoning Under Uncertainty

    Författare :Daniel de Leng; Fredrik Heintz; Patrick Doherty; Nick Hawes; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream reasoning; stream processing; temporal reasoning; spatial reasoning; configuration planning; intelligent robotics;

    Sammanfattning : Vast amounts of data are continually being generated by a wide variety of data producers. This data ranges from quantitative sensor observations produced by robot systems to complex unstructured human-generated texts on social media. LÄS MER

  7. 5. Spatio-Temporal Stream Reasoning with Adaptive State Stream Generation

    Författare :Daniel de Leng; Fredrik Heintz; Patrick Doherty; Emanuele Della Valle; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream reasoning; stream processing; temporal reasoning; spatial reasoning; configuration planning; intelligent robotics;

    Sammanfattning : A lot of today's data is generated incrementally over time by a large variety of producers. This data ranges from quantitative sensor observations produced by robot systems to complex unstructured human-generated texts on social media. With data being so abundant, making sense of these streams of data through reasoning is challenging. LÄS MER