{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T10:08:46Z","timestamp":1769854126432,"version":"3.49.0"},"reference-count":14,"publisher":"ASME International","issue":"2","content-domain":{"domain":["asmedigitalcollection.asme.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2008,1,24]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>In this paper, the classic Levy identification method is reviewed and reformulated using a complex representation. This new formulation addresses the well known bias of the classic method at low frequencies. The formulation is generic, coping with both integer order and fractional order transfer functions. A new algorithm based on a stacked matrix and its pseudoinverse is proposed to accommodate the data over a wide range of frequencies. Several simulation results are presented, together with a real system identification. This system is the Archimedes Wave Swing, a prototype of a device to convert the energy of sea waves into electricity.<\/jats:p>","DOI":"10.1115\/1.2833906","type":"journal-article","created":{"date-parts":[[2008,3,11]],"date-time":"2008-03-11T22:59:09Z","timestamp":1205276349000},"update-policy":"https:\/\/doi.org\/10.1115\/crossmarkpolicy-asme","source":"Crossref","is-referenced-by-count":50,"title":["Identifying a Transfer Function From a Frequency\n                    Response"],"prefix":"10.1115","volume":"3","author":[{"given":"Duarte","family":"Val\u00e9rio","sequence":"first","affiliation":[{"name":"Technical University of Lisbon IDMEC\/IST, , Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"given":"Manuel Duarte","family":"Ortigueira","sequence":"additional","affiliation":[{"name":"UNINOVA and DEE of Faculdade de Ci\u00eancias e Tecnologia of UNL , Campus da FCT da UNL, Quinta da Torre, 2825-114 Monte da Caparica, Portugal"}]},{"given":"Jos\u00e9","family":"S\u00e1 da Costa","sequence":"additional","affiliation":[{"name":"Technical University of Lisbon IDMEC\/IST, , Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]}],"member":"33","published-online":{"date-parts":[[2008,2,4]]},"reference":[{"key":"2022092113482330300_c1","volume-title":"System Identification:\n                        Theory for the User","author":"Ljung"},{"key":"2022092113482330300_c2","first-page":"37","article-title":"Complex Curve\n                        Fitting","volume":"4","author":"Levy","journal-title":"IRE Transactions on Automatic\n                        Control"},{"key":"2022092113482330300_c3","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1109\/TAC.1963.1105517","article-title":"Transfer Function\n                        Synthesis as a Ratio of Two Complex Polynomials","volume":"8","author":"Sanathanan","journal-title":"IEEE Transactions on Automatic Control"},{"key":"2022092113482330300_c4","unstructured":"Vinagre,\n                                B.\n          ,\n                        2001, \u201cModelado y\n                        Control de Sistemas Din\u00e1micos Caracterizados por Ecuaciones\n                        \u00cdntegro-Diferenciales de Orden Fraccional,\u201d Ph.D. thesis,\n                    Universidad Nacional de Educaci\u00f3n a Distancia, Madrid."},{"key":"2022092113482330300_c5","first-page":"1357","article-title":"Levy\u2019s\n                        Identification Method Extended to Commensurate Fractional Order Transfer\n                        Functions","volume-title":"Fifth EUROMECH Nonlinear Dynamics\n                        Conference","author":"Val\u00e9rio"},{"key":"2022092113482330300_c6","doi-asserted-by":"crossref","DOI":"10.1007\/978-1-4020-6042-7_16","article-title":"Identification of\n                        Fractional Models From Frequency Data","volume-title":"Advances\n                        in Fractional Calculus: Theoretical Developments and Applications in Physics\n                        and Engineering","author":"Val\u00e9rio"},{"key":"2022092113482330300_c7","article-title":"The History of\n                        and Progress in Wave Energy Conversion Devices","volume-title":"Ninth World Renewable Energy Conference","author":"Falc\u00e3o"},{"key":"2022092113482330300_c8","unstructured":"Boud,\n                            R.\n          ,\n                        2002, \u201cStatus and\n                        Research and Development Priorities 2003: Wave and Marine Current\n                        Energy,\u201d UK DTI Technical Report No. FES-R-132;"},{"key":"2022092113482330300_c9","article-title":"Ocean Energies:\n                        Resources and Utilisation","volume-title":"18th World Energy\n                        Conference","author":"Pontes"},{"key":"2022092113482330300_c10","unstructured":"Pinto,\n                                P.\n          ,\n                        2004, \u201cTime Domain\n                        Simulation of the AWS,\u201d MS thesis, Technical University of\n                    Lisbon, Portugal."},{"key":"2022092113482330300_c11","first-page":"161","article-title":"Modelling and\n                        Simulation of AWS: A Wave Energy Extractor","volume-title":"Proceedings of the Fourth IMACS Symposium on Mathematical\n                        Modelling","author":"S\u00e1 da Costa"},{"key":"2022092113482330300_c12","first-page":"91","article-title":"Time Domain Model\n                        of the Archimedes Wave Swing Wave Energy Converter","volume-title":"Proceedings of the Sixth European Wave and Tidal Energy\n                        Conference","author":"S\u00e1 da Costa"},{"key":"2022092113482330300_c13","doi-asserted-by":"publisher","first-page":"249","DOI":"10.1115\/1.1951779","article-title":"A Nearshore Wave\n                        Energy Atlas for Portugal","volume":"127","author":"Pontes","journal-title":"ASME J. Offshore Mech.\n                        Arct. Eng.","ISSN":"https:\/\/id.crossref.org\/issn\/0892-7219","issn-type":"print"},{"key":"2022092113482330300_c14","article-title":"Linear Model\n                        Identification of the Archimedes Wave Swing","volume-title":"IEEE\n                        International Conference on Power Engineering, Energy and Electrical\n                        Drives","author":"Beir\u00e3o"}],"container-title":["Journal of Computational and Nonlinear Dynamics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/asmedigitalcollection.asme.org\/computationalnonlinear\/article-pdf\/3\/2\/021207\/6918680\/021207_1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/asmedigitalcollection.asme.org\/computationalnonlinear\/article-pdf\/3\/2\/021207\/6918680\/021207_1.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,9,21]],"date-time":"2022-09-21T13:48:41Z","timestamp":1663768121000},"score":1,"resource":{"primary":{"URL":"https:\/\/asmedigitalcollection.asme.org\/computationalnonlinear\/article\/3\/2\/021207\/465213\/Identifying-a-Transfer-Function-From-a-Frequency"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,1,24]]},"references-count":14,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2008,1,24]]}},"URL":"https:\/\/doi.org\/10.1115\/1.2833906","relation":{},"ISSN":["1555-1415","1555-1423"],"issn-type":[{"value":"1555-1415","type":"print"},{"value":"1555-1423","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,1,24]]},"article-number":"021207"}}