Sökning: "NASA"

Visar resultat 1 - 5 av 26 avhandlingar innehållade ordet NASA.

  1. 1. Artificial Intelligence for Monitoring and Diagnosis of Robotic Spacecraft

    Författare :David John Atkinson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; robot plan execution; NASA; ; software systems; artificial intelligence algorithms;

    Sammanfattning : In this thesis the application of artificial intelligence to monitoring and diagnosis of robotic spacecraft is discussed. Several software prototype systems were developed to serve as testbeds for the research and to evaluate the effectiveness of the approach against real problems and current techniques used in NASA's planetary exploration program. LÄS MER

  3. 2. Stable FEM-FDTD Hybrid Method for Maxwell's Equations

    Författare :Thomas Rylander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite Element Method; scattering; antennas; stability analysis; edge elements; Maxwell s equations; NASA almond; microwave circuits; mass lumping; proof of stability; explicit-implicit time-stepping; Finite-Differences Time-Domain;

    Sammanfattning : In this thesis edge elements are applied to solve several problems in computational electromagnetics. In particular, a hybrid scheme joining the Finite Element Method (FEM) and the Finite-Difference Time-Domain (FDTD) algorithm is developed, tested and exploited. LÄS MER

  4. 3. A hybrid finite element method for electromagnetics with applications in time-domain

    Författare :DAVID DEGERFELDT; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nitsche s method; antenna arrays; NASA almond; edge elements; scattering; explicit-implicit time-stepping; Maxwell s equations; Finite Element Method; mass lumping; stability analysis; Finite-Differences Time-Domain; periodic structures; shape and material optimization;

    Sammanfattning : In this thesis, a new hybrid method that combines the Finite Element Method (FEM) with the Finite-Difference in Time-Domain (FDTD) method is presented. Tetrahedrons in the unstructured FEM region are connected directly to thehexahedrons in the structured FDTD region. LÄS MER

  5. 4. The application of edge elements in electromagnetics

    Författare :Thomas Rylander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite-differences time-domain; stability analysis; NASA almond; finite element method; edge elements; scattering; mass lumping;

    Sammanfattning : .... LÄS MER

  7. 5. Numerical modelling of ENAs from stellar wind interactions

    Författare :Andreas Ekenbäck; Mats Holmström; Michael R. Collier; Institutet för rymdfysik (IRF); []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Space physics; Space technology; Astrophysics; Space engineering; Rymdteknik;

    Sammanfattning : Energetic neutral atoms (ENAs) are produced whenever a stellar wind encounters a neutral atmosphere. If a stellar wind proton comes sufficiently close to a neutral a charge-exchange reaction may take place, transforming the proton into an ENA. LÄS MER