Sökning: "Variational method"

Visar resultat 31 - 35 av 84 avhandlingar innehållade orden Variational method.

1. 31. Machine learning for quantum information and computing

   Författare :Shahnawaz Ahmed; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum machine learning; quantum process tomography; quantum information; Machine learning; generative neural networks; variational quantum algorithms; quantum state tomography; optimization; quantum computing; Bayesian estimation;

   Sammanfattning : This compilation thesis explores the merger of machine learning, quantum information, and computing. Inspired by the successes of neural networks and gradient-based learning, the thesis explores how such ideas can be adapted to tackle complex problems that arise during the modeling and control of quantum systems, such as quantum tomography with noisy data or optimizing quantum operations, by incorporating physics-based constraints. LÄS MER

3. 32. On computational modeling of sintering based on homogenization

   Författare :Mikael Öhman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Computational homogenization; Multiscale; Mixed variational formulations; Incompressibility; FE2; Liquid phase sintering;

   Sammanfattning : Liquid-phase sintering is the process where a precompacted powder, “green body”, is heatedto the point where (a part of) the solid material melts, and the specimen shrinks while keeping(almost) net shape. In the case of hardmetal, the microstructure is defined by WC-Co-particleswith large pores, whereby molten Co represents the liquid phase. LÄS MER

4. 33. Supervised and Unsupervised Deep Learning Models for Flood Detection

   Författare :Ritu Yadav; Yifang Ban; Andrea Nascetti; Nicolas Audebert; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Floods; Remote Sensing; Sentinel-1 SAR; Segmentation; Change Detection; DEM; Data Fusion; Time Series; Deep Learning; Unsupervised Learning; Contrastive Learning; Self-Attention; Convolutional LSTM; Variational AutoEncoder VAE ; Geoinformatik; Geoinformatics;

   Sammanfattning : Human civilization has an increasingly powerful influence on the earthsystem. Affected by climate change and land-use change, floods are occurringacross the globe and are expected to increase in the coming years. Currentsituations urge more focus on efficient monitoring of floods and detecting impactedareas. LÄS MER

5. 34. Numerical Approximation of Solutions to Stochastic Partial Differential Equations and Their Moments

   Författare :Kristin Kirchner; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Petrov– Galerkin discretizations; Strong and weak convergence; Fractional operators; Finite element methods; Space-time variational problems; Tensor product spaces; Stochastic partial differential equations; White noise; Petrov– Galerkin discretizations;

   Sammanfattning : The first part of this thesis focusses on the numerical approximation of the first two moments of solutions to parabolic stochastic partial differential equations (SPDEs) with additive or multiplicative noise. More precisely, in Paper I an earlier result (A. Lang, S. Larsson, and Ch. LÄS MER

7. 35. Numerical Study of the Axisymmetric Ideal MHD Stability of EXTRAP

   Författare :Michal Benda; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : A numerical study of the free-boundary axisymmetric (n=0) ideal magnetohydrodynamical (MHD) motions of the EXTRAP device is presented. The dependence of stability on current profiles in the plasma and currents in the external conductors is investigated. LÄS MER