Essays about: "approximation approach"

Showing result 1 - 5 of 147 essays containing the words approximation approach.

  1. 1. Feature Selection for Microarray Data via Stochastic Approximation

    University essay from Göteborgs universitet/Institutionen för data- och informationsteknik

    Author : Erik Rosvall; [2024-03-18]
    Keywords : feature selection; feature ranking; microarray data; stochastic approximation; Barzilai and Borwein method; Machine Learning; AI;

    Abstract : This thesis explores the challenge of feature selection (FS) in machine learning, which involves reducing the dimensionality of data. The selection of a relevant subset of features from a larger pool has demonstrated its effectiveness in enhancing the performance of various machine learning algorithms. READ MORE

  3. 2. Spatio-temporal analysis of COVID-19 in Västra Götaland, Sweden

    University essay from Göteborgs universitet/Institutionen för matematiska vetenskaper

    Author : Natalia Andreeva; [2023-08-23]
    Keywords : ;

    Abstract : Spatio-temporal analysis of COVID-19 data with the two different statistical approaches is the main objective of this thesis. The first classical approach, the Endemic-Epidemic framework (Held et al., 2005) is a class of multivariate time-series models for the incidence counts, obtained from the surveillance systems. READ MORE

  4. 3. Branching Out with Mixtures: Phylogenetic Inference That’s Not Afraid of a Little Uncertainty

    University essay from KTH/Matematisk statistik

    Author : Ricky Molén; [2023]
    Keywords : Phylogeny; Bayesian analysis; Markov chain Monte Carlo; Variational inference; Mixture of proposal distributions; Fylogeni; Bayesiansk analys; Markov Chain Monte Carlo; Variationsinferens; Mixturer av förslagsfördelningar;

    Abstract : Phylogeny, the study of evolutionary relationships among species and other taxa, plays a crucial role in understanding the history of life. Bayesian analysis using Markov chain Monte Carlo (MCMC) is a widely used approach for inferring phylogenetic trees, but it suffers from slow convergence in higher dimensions and is slow to converge. READ MORE

  5. 4. Effects of Ultrafast Ionization in X-ray Coherent Diffraction Imaging

    University essay from KTH/Kemi

    Author : Arezu Sehati; [2023]
    Keywords : Coherent Diffraction Imaging; X-ray Free Electron Lasers; Refractive index; Core-shell nanoclusters; Rare-gas ionization; Koherent Diffraktionsavbildning; Röntgenfrielektronlaser; Brytningsindex; Core-shell-nanokluster; Ädelgasjonisering;

    Abstract : Koherent Diffraktionsavbildning med en intensiv röntgenpuls från en Frielektronlaser har möjliggjort strukturbestämning av isolerade nanopartiklar som inte går att studera med hjälp av konventionella metoder, så som elektronmikroskopi. En mycket kort pulslängd tillsammans med spridningssignalens beroende av objektets elektroniska struktur medför också möjligheten att studera inducerad ultrasnabb dynamik med denna teknik. READ MORE

  6. 5. Randomized Diagonal Estimation

    University essay from KTH/Matematik (Avd.)

    Author : Niclas Joshua Popp; [2023]
    Keywords : Diagonal estimation; randomized numerical linear algebra; low-rank approximation; matrix functions; Diagonalestimering; randomiserad numerisk linjär algebra; lågrankad approximation; matrisfunktioner;

    Abstract : Implicit diagonal estimation is a long-standing problem that is concerned with approximating the diagonal of a matrix that can only be accessed through matrix-vector products. It is of interest in various fields of application, such as network science, material science and machine learning. READ MORE