Sökning: "missing value"

Visar resultat 21 - 25 av 79 avhandlingar innehållade orden missing value.

  1. 21. Data Importance in Power System Asset Management

    Författare :Wadih Naim; Patrik Hilber; Miroslav Begovic; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Data availability; data quality; asset management; power systems; maintenance optimization; Datatillgänglighet; datakvalitet; tillgångsförvaltning; kraftsystem; underhållsoptimering; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The current shift towards a higher degree of data-driven decision making in power system asset management highlights the importance of asset data. This thesis identifies, investigates, and proposes methods for data-related research gaps that are encountered by asset managers. These research gaps are in data availability and data quality. LÄS MER

  3. 22. First principles studies of CO2 activation and reduction over indium oxide and copper surfaces

    Författare :Alvaro Posada Borbon; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; CO2 reduction; indium oxide; Heterogeneous catalysis; methanol conversion; Density Functional Theory; copper surface;

    Sammanfattning : Catalytic recycling of carbon dioxide (CO2) to added-value chemicals, such as methanol (CH3OH), have been proposed as a possible path for sustainable production of fuel and chemicals, in addition to providing a route to mitigate anthropogenic carbon emissions. Several catalytic systems are known to be active for conversion of CO2 to methanol, Cu/ZnO/Al2O3 being the main industrial catalyst for the process. LÄS MER

  4. 23. Analysis of the phase space, asymptotic behavior and stability for heavy symmetric top and tippe top

    Författare :Markus Sköldstam; Stefan Rauch-Wojciechowski; Torkel Glad; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; symmetric top; tippe top; vertical rotation; truncated sphere; asymptotic trajectories; MATHEMATICS; MATEMATIK;

    Sammanfattning : In this thesis we analyze the phase of the heavy symmetric top and the tippe top. These tops are two examples of physical systems for which the usefulness of integrals of motion and invariant manifolds, in phase space picture analysis, can be illustratedIn the case of the heavy symmetric top, simplified proofs of stability of the vertical rotation have been perpetuated by successive textbooks during the last century. LÄS MER

  5. 24. PET and MRI of Prostate Cancer

    Författare :Catrin von Below; Håkan Ahlström; Cecilia Wassberg; Mauritz Waldén; Jens Sörensen; Michael Häggman; Joel Kullberg; Katrine Åhlström Riklund; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Prostate cancer; lymph nodes; lymph node staging; PET CT; MRI DWI; extended pelvic lymph node dissection; targeted biopsies; multi-parametric MRI; TRUS guided biopsy; multiple regression analysis;

    Sammanfattning : Prostate cancer (PCa) is the most common non-skin malignancy of men in developed countries. In spite of treatment with curative intent up to 30-40% of patients have disease recurrence after treatment, resulting from any combination of lymphatic, hematogenous, or contiguous local spread. LÄS MER

  7. 25. Boreal vegetation responses to forestry as reflected in field trial and survey data and the quality of cover estimates and presence/absence in vegetation inventory

    Författare :Johan Bergstedt; Per Milberg; Göran Ståhl; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boreal forest; cutting intensity; scarification; cover estimates; presence absence; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : Den här avhandlingen belyser hur avverkning och markberedning påverkar markfloran i den svenska barrskogen. Dessutom utvärderas två inventeringsmetoder som används inom växtekologin. LÄS MER