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<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.0 20120330//EN" "JATS-journalpublishing1.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article"><front><journal-meta><journal-id journal-id-type="publisher-id">INFORMATICA</journal-id><journal-title-group><journal-title>Informatica</journal-title></journal-title-group><issn pub-type="epub">0868-4952</issn><issn pub-type="ppub">0868-4952</issn><publisher><publisher-name>VU</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">inf23406</article-id><article-id pub-id-type="doi">10.15388/Informatica.2012.377</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research article</subject></subj-group></article-categories><title-group><article-title>Multimodal Evolutionary Algorithm for Multidimensional Scaling with City-Block Distances</article-title></title-group><contrib-group><contrib contrib-type="Author"><name><surname>Redondo</surname><given-names>Juana López</given-names></name><email xlink:href="mailto:jlredondo@atc.ugr.es">jlredondo@atc.ugr.es</email><xref ref-type="aff" rid="j_INFORMATICA_aff_000"/></contrib><contrib contrib-type="Author"><name><surname>Ortigosa</surname><given-names>Pilar Martínez</given-names></name><email xlink:href="mailto:ortigosa@ual.es">ortigosa@ual.es</email><xref ref-type="aff" rid="j_INFORMATICA_aff_001"/></contrib><contrib contrib-type="Author"><name><surname>Žilinskas</surname><given-names>Julius</given-names></name><email xlink:href="mailto:julius.zilinskas@mii.vu.lt">julius.zilinskas@mii.vu.lt</email><xref ref-type="aff" rid="j_INFORMATICA_aff_002"/></contrib><aff id="j_INFORMATICA_aff_000">Department of Computer Architecture and Technology, University of Granada, Periodista Daniel Saucedo Aranda, s/n. 18071 Granada, Spain</aff><aff id="j_INFORMATICA_aff_001">Department of Informatics, University of Almería, Campus de Excelencia Internacional Agroalimentario (ceiA3), Spain</aff><aff id="j_INFORMATICA_aff_002">Vilnius University Institute of Mathematics and Informatics, Akademijos 4, LT-08663 Vilnius, Lithuania</aff></contrib-group><pub-date pub-type="epub"><day>01</day><month>01</month><year>2012</year></pub-date><volume>23</volume><issue>4</issue><fpage>601</fpage><lpage>620</lpage><history><date date-type="received"><day>01</day><month>09</month><year>2012</year></date><date date-type="accepted"><day>01</day><month>12</month><year>2012</year></date></history><abstract><p>Multidimensional scaling with city-block distances is considered in this paper. The technique requires optimization of an objective function which has many local minima and can be non-differentiable at minimum points. This study is aimed at developing a fast and effective global optimization algorithm spanning the whole search domain and providing good solutions. A multimodal evolutionary algorithm is used for global optimization to prevent stagnation at bad local optima. Piecewise quadratic structure of the least squares objective function with city-block distances has been exploited for local improvement. The proposed algorithm has been compared with other algorithms described in literature. Through a comprehensive computational study, it is shown that the proposed algorithm provides the best results. The algorithm with fine-tuned parameters finds the global minimum with a high probability.</p></abstract><kwd-group><label>Keywords</label><kwd>multidimensional scaling</kwd><kwd>city-block distances</kwd><kwd>evolutionary algorithms</kwd><kwd>multimodal algorithms</kwd></kwd-group></article-meta></front></article>