Sökning: "HERA"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet HERA.

  1. 1. Underactuated mechanical systems : Contributions to trajectory planning, analysis, and control

    Författare :Pedro La Hera; Anton Shiriaev; Ambarish Goswami; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Underactuated mechanical systems; mechanical systems with impacts; trajectory planning; periodic trajectories; orbital stabilization; walking robots; virtual holonomic constraints; transverse linearization; Automatic control; Reglerteknik; Automatic Control; reglerteknik;

    Sammanfattning : Nature and its variety of motion forms have inspired new robot designs with inherentunderactuated dynamics. The fundamental characteristic of these controlled mechanicalsystems, called underactuated, is to have the number of actuators less than the number ofdegrees of freedom. LÄS MER

  3. 2. Surface analysis of low dimensional materials : revealing their electronic properties by advanced spectroscopy

    Författare :Vladimir Miranda la Hera; Thomas Wågberg; Eduardo Gracia-Espino; Tomas Edvinsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Low-dimensional materials; surface science; surface-sensitive techniques; angle-resolved photoemission spectroscopy; ultraviolet photoemission spectroscopy; electronic properties;

    Sammanfattning : Low-dimensional materials (0D, 1D, 2D) have been widely used to develop modern miniaturized (micro- and nano-) technology. The use of these materials come from their extraordinary optical, electrical, thermal, and mechanical properties, which are very different from the bulk crystal. LÄS MER

  4. 3. Contributions to motion planning and orbital stabilization : case studies: Furuta pendulum swing up, inertia wheel oscillations and biped robot walking

    Författare :Pedro Xavier Miranda La Hera; Anton Shiriaev; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Under-actuated Systems; Orbital Exponential Stability; Motion Planning; Virtual Constraints; Walking robots; Automatic control; Reglerteknik;

    Sammanfattning : Generating and stabilizing periodic motions in nonlinear systems is a challenging task. In the control system community this topic is also known as limit cycle control. In recent years a framework known as Virtual Holonomic Constraints (VHC) has been developed as one of the solutions to this problem. LÄS MER

  5. 4. Multiple Parton Interactions in Deep Inelastic ep-scattering at HERA

    Författare :Sakar Osman; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Jet Calibration; H1; Jets; Mini-jets; MPI; Low-x; Multiple; Dijets; Parton Dynamics; HERA; Fysicumarkivet A:2008:Osman;

    Sammanfattning : The production of jets with low transverse momenta (mini-jets) in deep inelastic electron-proton scattering is studied. The analyses uses data taken with the H1 detector at HERA during the years 1999 to 2000. LÄS MER

  7. 5. Azimuthal Correlations in Dijet Events from Deep Inelastic Positron-Proton Scattering at HERA

    Författare :Magnus Hansson; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elementary particle physics; Jets; Azimuthal Correlations; Dijets; Parton Dynamics; Low-x; H1; HERA; quantum field theory; Elementarpartikelfysik; kvantfältteori; Fysicumarkivet A:2007:Hansson;

    Sammanfattning : Correlations in the azimuthal angle between dijets produced in deep inelastic $e^{+}p$ scattering events, collected by the H1 experiment during 1999-2000, have been investigated. Cross sections are presented as a function of the azimuthal separation between the two jets in the hadronic center of mass frame, $Deltaphi^{*}$, in different regions of the photon virtuality $Q^{2}$ and in different regions of the Bjorken scaling variable $x_{Bj}$. LÄS MER