Sökning: "mesh sensitivity"

Visar resultat 6 - 10 av 34 avhandlingar innehållade orden mesh sensitivity.

1. 6. Shape and material optimization for antenna applications

   Författare :Per Jacobsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; explicit-implicit time stepping; sensitivity analysis; Nitsche s method; total scattering cross section; shape and material optimization; array antennas; finite element method;

   Sammanfattning : In this thesis, a gradient-based method for shape and material optimization fortwo antenna applications is presented: minimization of the active reflectioncoefficient for conformal array antennas; and minimization of the totalscattering cross section for cylindrical scatterers. The sensitivity of theobjective function with respect to changes of the shape and material of the geometry isexpressed in terms of the original field problem and an adjoint field problem. LÄS MER

3. 7. Grey-box Identification of Distributed Parameter Systems

   Författare :Yi Liu; Elling W. Jacobsen; Denis Dochain; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; grey-box modeling; grey-box identification; model reduction; PDE; chromatography; bifurcation; moving mesh methods; orthogonal collocation on moving finite elements; OCMFE; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Sammanfattning : This thesis considers the problem of making dynamic models for industrial processes by combining physical modelling with experimental data. The focus is on distributed parameter systems, that is, systems for which the model structure involves partial differential equations (PDE). Distributed parameter systems are important in many applications, e. LÄS MER

4. 8. Space-adaptive simulation of transition and turbulence in shear flows

   Författare :Daniele Massaro; Philipp Schlatter; Saleh Rezaeiravesh; Alfredo Pinelli; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; global stability; coherent structures; adaptive mesh refinement; Turbulens; global stabilitet; koherenta strukturer; adaptiv nätförfining; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : Transitional and turbulent shear flows are ubiquitous, from the boundary layer developing on an aeroplane wing to the flow within the aortic arch. In this thesis, we study wall-bounded and free shear flows through direct numerical simulations. LÄS MER

5. 9. Aspects on finite element simulation of sheet metal forming processes

   Författare :Ramin Moshfegh; Kjell Mattiasson; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sheet metal forming process; Forming Limit Diagram; Metallurgical manufacturing engineering; Metallurgisk produktionsteknik;

   Sammanfattning : This thesis has focused on four different aspects of finite element simulation of sheet metal forming processes. Four substantial research areas are the development of a methodology for predicting the limiting strains in connection with the Forming Limit Diagram, the applicable mode of procedure for finite element simulation of the hydromechanical deep drawing process, the adaptive mesh refinement strategy based on gradients of the effective plastic stresses and strains; and the reliability and sensitivity assessments within sheet metal forming processes. LÄS MER

7. 10. Dexterous Grasping : Representation and Optimization

   Författare :Kaiyu Hang; Nancy Pollard; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dexterous Grasping; Hierarchical Fingertip Space; Grasp Planning; Grasp Adaptation; Computer Science; Datalogi;

   Sammanfattning : Many robot object interactions require that an object is firmly held, and that the grasp remains stable during the whole manipulation process. Based on grasp wrench space, this thesis address the problems of measuring the grasp sensitivity against friction changes, planning contacts and hand configurations on mesh and point cloud representations of arbitrary objects, planning adaptable grasps and finger gaiting for keeping a grasp stable under various external disturbances, as well as learning of grasping manifolds for more accurate reachability and inverse kinematics computation for multifingered grasping. LÄS MER