Improving sparsity in online kernel models

In this thesis, background theory about the online kernel-based algorithms and their use for online learning is presented. The analysis of the state-ofthe- art methods highlights an important drawback in many kernel online learning algorithms. This is the large memory storage needed due to the amoun...

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Detalles Bibliográficos
Autor: Orihuela Salvatierra, Helena
Tipo de recurso: tesis de maestría
Fecha de publicación:2013
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2099.1/20440
Acceso en línea:https://hdl.handle.net/2099.1/20440
Access Level:acceso abierto
Palabra clave:Kernel functions
Machine learning
Kernel, Funcions de
Aprenentatge automàtic
Àrees temàtiques de la UPC::Informàtica::Intel·ligència artificial::Aprenentatge automàtic
Descripción
Sumario:In this thesis, background theory about the online kernel-based algorithms and their use for online learning is presented. The analysis of the state-ofthe- art methods highlights an important drawback in many kernel online learning algorithms. This is the large memory storage needed due to the amount of support vectors generated. We study the SCA approach for reducing support vectors in the batch learning case and propose its adaptation to the online scenario. POLSCA is the algorithm proposed for solving the addressed problems that online learning presents. The proposed algorithm is constructed by merging the concepts of Primal formulation of the optimization problem, online learning with stochastic subgradient descent solver(PEGASOS) and the support vector reduction method SCA.