An optimized unsupervised manifold learning algorithm for manycore architectures

Autor(es)

Baldassin, Alexandro ^[1] ; Weng, Ying ^[2] ; Guimaraes Pedronette, Daniel Carlos ^[1] ; Almeida, Jurandy ^[3]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Dept Stat Appl Math & Comp, BR-13506900 Rio Claro, SP - Brazil

^[2] Bangor Univ, Sch Comp Sci, Bangor LL57 1UT, Gwynedd - Wales

^[3] Univ Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12247014 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INFORMATION SCIENCES; v. 496, p. 410-430, SEP 2019.
• Citações Web of Science: 1

Resumo

Multimedia data, such as images and videos, has become very popular in people's daily life as a result of the widespread use of mobile devices. The ever-increasing amount of such data, along with the necessity for real-time retrieval, has lead to the development of new methods that can process them in a timely fashion with acceptable accuracy. In this paper, we study the performance of ReckNN, an unsupervised manifold learning algorithm based on the reciprocal neighbourhood and the authority of ranked lists. Most of the related work in this field do not fully investigate optimization strategies, an aspect that is becoming more important with the high availability of manycore machines. In order to address that issue, we fully investigate optimization opportunities in this article and make the following three main contributions. Firstly, we develop an efficient and scalable method for storing and accessing the distances between objects (e.g., video or image) based on dictionaries. Secondly, we employ memoization to speed up the computation of authority scores, leading to a significant performance gain even on single-core architectures. Lastly, we devise and implement several parallelization strategies and show that they are scalable on a 72-core Intel machine. The experimental results with MPEG-7, Corel5k and MediaEval benchmarks show that the optimized ReckNN delivers both efficiency and scalability, highlighting the importance of the proposed optimizations for manycore machines. (C) 2018 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 16/06441-7 - Recuperação de informação semântica em grandes bases de vídeos
• Beneficiário: Jurandy Gomes de Almeida Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/08645-0 - Reclassificação e agregação de listas para tarefas de recuperação de imagens
• Beneficiário: Daniel Carlos Guimarães Pedronette
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores