Sökning: "adjoint method"

Visar resultat 1 - 5 av 47 avhandlingar innehållade orden adjoint method.

  1. 1. Reconciling gene family evolution and species evolution

    Författare :Joel Sjöstrand; Jens Lagergren; Nicolas Lartillot; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational biology; Bioinformatics; Phylogenetics; Phylogenomics; Comparative genomics; Evolutionary biology; datalogi; Computer Science;

    Sammanfattning : Species evolution can often be adequately described with a phylogenetic tree. Interestingly, this is the case also for the evolution of homologous genes; a gene in an ancestral species may – through gene duplication, gene loss, lateral gene transfer (LGT), and speciation events – give rise to a gene family distributed across contemporaneous species. LÄS MER

  3. 2. Analysis, Control, and Design Optimization of Engineering Mechanics Systems

    Författare :Esubalewe Lakie Yedeg; Martin Berggren; Eddie Wadbro; Anton Evgrafov; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topology optimization; Helmholtz equation; acoustic impedance; anisotropic filter; thin structures; finite element method; Nitsche-type method; interface problem; Optimal control; adjoint method; business data processing; administrativ databehandling;

    Sammanfattning : This thesis considers applications of gradient-based optimization algorithms to the design and control of some mechanics systems. The material distribution approach to topology optimization is applied to design two different acoustic devices, a reactive muffler and an acoustic horn, and optimization is used to control a ball pitching robot. LÄS MER

  4. 3. Shape Optimization for Acoustic Wave Propagation Problems

    Författare :Rajitha Udawalpola; Martin Berggren; Pekka Neittaanmäki; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shape optimization; design optimization; acoustic wave propagation; Helmholtz equation; Boundary Element Method; Finite Element Method; inverse problems; adjoint method; gradient-based optimization; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Boundary shape optimization is a technique to search for an optimal shape by modifying the boundary of a device with a pre-specified topology. We consider boundary shape optimization of acoustic horns in loudspeakers and brass wind instruments. LÄS MER

  5. 4. Numerical ice sheet modeling : Forward and inverse problems

    Författare :Gong Cheng; Lina von Sydow; Per Lötstedt; Nina Kirchner; Irina Tezaur; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ice sheet modeling; finite element method; grounding line migration; inverse problems; adjoint method; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Ice sheets have strong influence on the climate system. Numerical simulation provides a mathematical tool to study the ice dynamics in the past and to predict their contribution to climate change in the future. Large scale ice sheets behave as incompressible non-Newtonian fluid. LÄS MER

  7. 5. A hybrid finite element method for electromagnetics with applications in time-domain

    Författare :DAVID DEGERFELDT; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nitsche s method; antenna arrays; NASA almond; edge elements; scattering; explicit-implicit time-stepping; Maxwell s equations; Finite Element Method; mass lumping; stability analysis; Finite-Differences Time-Domain; periodic structures; shape and material optimization;

    Sammanfattning : In this thesis, a new hybrid method that combines the Finite Element Method (FEM) with the Finite-Difference in Time-Domain (FDTD) method is presented. Tetrahedrons in the unstructured FEM region are connected directly to thehexahedrons in the structured FDTD region. LÄS MER