Sökning: "B-splines"

Visar resultat 1 - 5 av 13 avhandlingar innehållade ordet B-splines.

  1. 1. Computer Aided Angioplasty : Patient-specific arterial modeling and smooth 3D contact analysis of the stent-balloon-artery interaction

    Författare :Dimitrios Kiousis; Gerhard Holzapfel; Kenneth Runesson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Contact; continuous surfaces; B-splines; balloon angioplasty; stenting; FEM; Bioengineering; Bioteknik;

    Sammanfattning : Paper A: In this paper, the development and implementation of a contact algorithm based on C2-continuous surface representations is discussed. In 3D contact simulations involving models with arbitrarily curved surfaces (as in the case of vessel walls), the discretization of the contact surfaces by means of facet-based techniques could lead to numerical instabilities and finally loss of quadratic convergence. LÄS MER

  3. 2. Path-planning with obstacle-avoiding minimum curvature variation B-splines

    Författare :Tomas Berglund; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

    Sammanfattning : We study the general problem of computing an obstacle-avoiding path that, for a prescribed weight, minimizes the weighted sum of a smoothness measure and a safety measure of the path. We consider planar curvature-continuous paths, that are functions on an interval of a room axis, for a point-size vehicle amidst obstacles. LÄS MER

  4. 3. Trajectory Tracking and Prediction-Based Coordination of Underactuated Unmanned Vehicles

    Författare :Dzenan Lapandic; Bo Wahlberg; Antonio Pedro Aguiar; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, we study trajectory tracking and prediction-based control of underactuated unmanned aerial and surface vehicles.  In the first part of the thesis, we examine the trajectory tracking using prescribed performance control (PPC) assuming that the model parameters are unknown. LÄS MER

  5. 4. Many-Body effects in Semiconductor Nanostructures

    Författare :Carl-Johan Wesslén; Eva Lindroth; Morten Førre; Stockholms universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; coupled cluster; nanostructure; quantum dot; quantum ring; concentric quantum ring; many body pertubation theory; fysik; Physics;

    Sammanfattning : Low dimensional semiconductor structures are modeled using techniques from the field of many-body atomic physics. B-splines are used to create a one-particle basis, used to solve the more complex many-body problems. LÄS MER

  7. 5. Estimation of electromagnetic material properties with application to high-voltage power cables

    Författare :Yevhen Ivanenko; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material losses; power cables; cylindrical multipole expansion; Herglotz functions; convex optimization; sum rules; Waves and Signals; Vågor och signaler;

    Sammanfattning : Efficient design of high-voltage power cables is important to achieve an economical delivery of electric power from wind farms and power plants over the very long distances as well as the overseas electric power. The main focus of this thesis is the investigation of electromagnetic losses in components of high-voltage power cables. LÄS MER