Sökning: "dimensionality reduction"

Visar resultat 1 - 5 av 51 avhandlingar innehållade orden dimensionality reduction.

1. 1. Online Dimensionality Reduction

   Författare :Kaito Ariu; Alexandre Proutiere; Mikael Johansson; Richard Combes; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : In this thesis, we investigate online dimensionality reduction methods, wherethe algorithms learn by sequentially acquiring data. We focus on two specificalgorithm design problems in (i) recommender systems and (ii) heterogeneousclustering from binary user feedback. LÄS MER

3. 2. Nonlinear dimensionality reduction of gene expression data

   Författare :Jens Nilsson; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gene expression; Manifold learning; Nonlinear dimensionality reduction; Microarray;

   Sammanfattning : Using microarray measurements techniques, it is possible to measure the activity of genes simultaneously across the whole genome. Since genes influence each others activity levels through complex regulatory networks, such gene expression measurements are state samples of a dynamical system. LÄS MER

4. 3. Nearest Neighbor Classification in High Dimensions

   Författare :Sampath Deegalla; Henrik Boström; Slawomir Nowaczyk; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nearest Neighbor; High-Dimensional Data; Curse of Dimensionality; Dimensionality Reduction; data- och systemvetenskap; Computer and Systems Sciences;

   Sammanfattning : The simple k nearest neighbor (kNN) method can be used to learn from high dimensional data such as images and microarrays without any modification to the original version of the algorithm. However, studies show that kNN's accuracy is often poor in high dimensions due to the curse of dimensionality; a large number of instances are required to maintain a given level of accuracy in high dimensions. LÄS MER

5. 4. Generalized Hebbian Algorithm for Dimensionality Reduction in Natural Language Processing

   Författare :Genevieve Gorrell; Arne Jönsson; Robin Cooper; Alexander Rudnicky; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Generalized Hebbian Algorithm; Language Modelling; Singular Value Decomposition; Eigen Decomposition; Latent Semantic Analysis; Vector Space Models; Computational linguistics; Datorlingvistik;

   Sammanfattning : The current surge of interest in search and comparison tasks in natural language processing has brought with it a focus on vector space approaches and vector space dimensionality reduction techniques. Presenting data as points in hyperspace provides opportunities to use a variety of welldeveloped tools pertinent to this representation. LÄS MER

7. 5. Methodology and Infrastructure for Statistical Computing in Genomics : Applications for Ancient DNA

   Författare :Kristiina Ausmees; Carl Nettelblad; Mattias Jakobsson; Flora Jay; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; statistical computing; genotype imputation; ancient DNA; deep learning; dimensionality reduction; genetic clustering; distributed computing; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : This thesis concerns the development and evaluation of computational methods for analysis of genetic data. A particular focus is on ancient DNA recovered from archaeological finds, the analysis of which has contributed to novel insights into human evolutionary and demographic history, while also introducing new challenges and the demand for specialized methods. LÄS MER