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[{"key": "dc.contributor.advisor", "value": "Neri, Ferrante", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Koskinen, Pekka", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Peltonen, Teemu", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2015-06-08T12:12:20Z", "language": "", "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2015-06-08T12:12:20Z", "language": "", "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2015", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.other", "value": "oai:jykdok.linneanet.fi:1475431", "language": null, "element": "identifier", "qualifier": "other", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/46236", "language": "", "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Vaikka globaalit optimointiongelmat ovat hyvin yleisi\u00e4 laskennallisen nanotieteen alalla, ne ovat my\u00f6s laskennallisesti eritt\u00e4in vaativia ongelmia, joille tehokkaita ja yleisi\u00e4 ratkaisualgoritmeja ei ole saatavilla. T\u00e4ss\u00e4 ty\u00f6ss\u00e4 teen yleiskatsauksen algoritmeihin, joiden tavoitteena on olla juuri t\u00e4llaisia yleisi\u00e4 menetelmi\u00e4, joita voi soveltaa tehokkaasti mihin ongelmaan tahansa. Rajoittuessani niin kutsuttuihin populaatiopohjaisiin metaheuristiikkoihin, erityisesti luonnosta ideansa saaneisiin evolutiivisiin algoritmeihin ja parvi\u00e4lyyn, tutkin niiden kyvykkyytt\u00e4 ratkaista er\u00e4s vaikea todellisen maailman ongelma, Lennard-Jones-atomirypp\u00e4\u00e4n rakenneongelma. K\u00e4yt\u00e4n lis\u00e4ksi yht\u00e4 algoritmeista, CCPSO2:ta, Lennard-Jones ongelman separoituvuusanalyysiin eli siihen, kuinka hyvin kyseisen ongelman voi ratkaista jakamalla se pienempiin osaongelmiin.\r\n\r\nLennard-Jones-ongelman tutkiminen 200 atomiin asti osoittaa, ett\u00e4 kyseiset menetelm\u00e4t voivat olla h\u00e4mm\u00e4stytt\u00e4v\u00e4n tehokkaita optimoijia jopa korkeadimensioisissa todellisen maailman ongelmissa. Erityisesti yksi menetelmist\u00e4, CCPSO2, kykenee arvioimaan Lennard-Jones-atomirypp\u00e4iden globaaleja minimej\u00e4 10\u201320 % virheell\u00e4 dimensiosta riippumatta, ja viel\u00e4p\u00e4 todella v\u00e4h\u00e4ll\u00e4 m\u00e4\u00e4r\u00e4ll\u00e4 raskaita energiafunktiokutsuja. N\u00e4yt\u00e4n lis\u00e4ksi, ett\u00e4 n\u00e4m\u00e4 menetelm\u00e4t ovat ylivoimaisia verrattuna kahteen simuloidun j\u00e4\u00e4hdytyksen versioon. Simuloitu j\u00e4\u00e4hdytys on fyysikoiden keskuudessa suosittu luokka globaalin optimoinnin ratkaisualgoritmeja.\r\n\r\nK\u00e4ytt\u00e4m\u00e4ll\u00e4 CCPSO2:ta jakamaan Lennard-Jones-ongelma pienempiin, dimensioiltaan erikokoisiin osaongelmiin, n\u00e4yt\u00e4n ett\u00e4 tehokkain tapa ratkaista kyseinen ongelma on jakaa se eritt\u00e4in pieniin 4\u201312 dimension osaongelmiin riippumatta ongelman dimensiosta. T\u00e4m\u00e4 on merkitt\u00e4v\u00e4 tulos, sill\u00e4 jako n\u00e4in pieniin ongelmiin helpottaa vaikean Lennard-Jones-ongelman ratkaisua merkitt\u00e4v\u00e4sti, ja se toimii suuntaviivana kyseiselle ongelmalle viel\u00e4kin tehokkaampia algoritmeja kehitt\u00e4ville tutkijoille.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "While global optimization problems are very common when working in computational nanoscience, they also constitute a set of computationally very demanding problems that lack efficient all-round optimizers. In this thesis I do a small survey on algorithms that try to be exactly like this; general methods that can be applied to any problem off the shelf. Constraining myself to so-called population-based metaheuristics, especially Nature-inspired evolutionary algorithms and swarm intelligence, I study their capabilities of solving a difficult real-world optimization problem, the Lennard-Jones cluster structure problem. I also use one of the algorithms, CCPSO2, to study the Lennard-Jones problem's separability, that is, how well it can be solved by dividing the problem into smaller subproblems.\r\n\r\nAn analysis on the Lennard-Jones problem of up to 200 atoms shows that these methods can be surprisingly efficient optimizers even in high-dimensional real-world problems. Especially one algorithm, namely CCPSO2, provides quite good and robust approximations for the global minima of the Lennard-Jones clusters with an error of around 10\u201320 %, and all that with a very small number of heavy energy function evaluations. I also show that they are superior to two versions of simulated annealing algorithms, a popular class of global optimization methods among physicists.\r\n\r\nBy using CCPSO2 to divide the Lennard-Jones problem into smaller pieces of different dimensionalities, I show that the most efficient way to solve it is to divide the problem into subproblems of only 4\u201312 dimensions, regardless of the problem dimension. This is a remarkable result since this division dramatically decreases the difficulty of the Lennard-Jones problem and it serves as a guide for people trying to develop even more efficient algorithms for this problem.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted using Plone Publishing form by Teemu Peltonen (tejupelt) on 2015-06-08 12:12:19.823262. Form: Pro gradu -lomake (https://kirjasto.jyu.fi/julkaisut/julkaisulomakkeet/pro-gradu-lomake). JyX data: [jyx_publishing-allowed (fi) =True]", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by jyx lomake-julkaisija (jyx-julkaisija.group@korppi.jyu.fi) on 2015-06-08T12:12:20Z\r\nNo. of bitstreams: 2\r\nURN:NBN:fi:jyu-201506082229.pdf: 1354374 bytes, checksum: 04de5ed952f66e6067e59a7ba830dbd6 (MD5)\r\nlicense.html: 4839 bytes, checksum: dafa5899acd54a084ff0b5ef3c8db465 (MD5)", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2015-06-08T12:12:20Z (GMT). No. of bitstreams: 2\r\nURN:NBN:fi:jyu-201506082229.pdf: 1354374 bytes, checksum: 04de5ed952f66e6067e59a7ba830dbd6 (MD5)\r\nlicense.html: 4839 bytes, checksum: dafa5899acd54a084ff0b5ef3c8db465 (MD5)\r\n Previous issue date: 2015", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "1 verkkoaineisto (68s.)", "language": null, "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "metaheuristiikka", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Comparative study of population-based metaheuristic methods in global optimization", "language": null, "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-201506082229", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Fysiikan laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Physics", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Teoreettinen fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Theoretical Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.date.updated", "value": "2015-06-08T12:12:21Z", "language": "", "element": "date", "qualifier": "updated", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": "fi", "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "masterThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4024", "language": null, "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "optimointi", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "algoritmit", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.format.content", "value": "fulltext", "language": null, "element": "format", "qualifier": "content", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}, {"key": "dc.type.okm", "value": "G2", "language": null, "element": "type", "qualifier": "okm", "schema": "dc"}]
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