Sökning: "Dynamic factor model"

Visar resultat 1 - 5 av 187 avhandlingar innehållade orden Dynamic factor model.

  1. 1. Transient Air to Fuel Ratio Response in a Fuel Injected S.I Engine

    Författare :Göran Almkvist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; dynamic; A F; model; transient; air to fuel; response; time constant; film; behavior; lambda; time-delay; fuel; mass; deposit factor;

    Sammanfattning : Future emission standards make it necessary to focus on the conditions under which engine emissions are produced, especially before the catalyst light off. During practical driving conditions, such as those represented by the FTP 75 test cycle, the engine is operated very much under transient conditions regarding load and speed. LÄS MER

  3. 2. Variational Inference of Dynamic Factor Models

    Författare :Erik Spånberg; Pär Stockhammar; Gebrenegus Ghilagaber; Sune Karlsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dynamic factor models; variational inference; missing data; nowcasting; expectation maximization; statistik; Statistics;

    Sammanfattning : When we make difficult and crucial decisions, forecasts are powerful and important tools. For that purpose, statistical models can be our most effective aid. Ideally, these models can incorporate large sets of multifaceted data. LÄS MER

  4. 3. Likelihood-Based Panel Unit Root Tests for Factor Models

    Författare :Xingwu Zhou; Johan Lyhagen; Joakim Westerlund; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Panel unit root; Exact factor model; Dynamic factor model; Maximum likelihood; Principal components; Lagrange multiplier;

    Sammanfattning : The thesis consists of four papers that address likelihood-based unit root tests for panel data with cross-sectional dependence arising from common factors.In the first three papers, we derive Lagrange multiplier (LM)-type tests for common and idiosyncratic unit roots in the exact factor models based on the likelihood function of the differenced data. LÄS MER

  5. 4. Modelling, Analysis, and Control Aspects of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator

    Författare :Naveed ur Rehman Malik; Chandur Sadarangani; Torbjörn Thiringer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brushless doubly-fed induction generator; dual vector control; dynamic model; induction machine; internal model control; Lindmark concept; low-voltage ride-through; passive resistive network; rotating power electronic converter; rotating exciter; symmetrical faults; synchronous machine; thermal model; unity power factor; unsymmetrical faults; vector control; wind turbines.; Electrical Engineering; Elektro- och systemteknik; Energy Technology; Energiteknik;

    Sammanfattning : This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G).A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. LÄS MER

  7. 5. Multiscale modeling of dynamic recrystallization

    Författare :Ylva Mellbin; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic recrystallization; Crystal plasticity; Texture; Grain size strengthening; Vertex model; Nucleation; Particle pinning; Large deformations; Multiscale modeling; GPGPU;

    Sammanfattning : During thermomechanical processing of metals, changes occur in the microstructure of the material which affect its macroscopic properties. By understanding these transformations in the microstructure, it becomes possible to design the processes in a way which yields the desired properties in the finished product. LÄS MER