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An experimental study of the GAMS/AlphaECP MINLP solver / Toni Lastusilta in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7337–7345 Titre : An experimental study of the GAMS/AlphaECP MINLP solver Type de document : texte imprimé Auteurs : Toni Lastusilta, Auteur ; Michael R. Bussieck, Auteur ; Tapio Westerlund, Auteur Année de publication : 2009 Article en page(s) : pp. 7337–7345 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Mixed-integer  nonlinear  programming  problems  General  algebraic  modeling  system  GAMS/AlphaECP Résumé : The development of methods to solve mixed-integer nonlinear programming (MINLP) problems has given rise to new solvers and improved the current ones. In this Article, the focus is set on the MINLP solvers in the General Algebraic Modeling System (GAMS) and especially GAMS/AlphaECP. In this Article, a comprehensive comparison of the MINLP solvers is made. In June 2007, GAMS introduced new MINLP solvers: CoinBonmin, AlphaECP, and LINDOGlobal. A description of the improvements made in the second half of 2007 to AlphaECP is given, and the performance of the MINLP solvers in GAMS is examined. Furthermore, the performance of AlphaECP for both MINLP and nonlinear programming (NLP) problems is studied, in conjunction with different subsolvers. Two large collections of problems, MINLPLib and GLOBALLib, are used for all solver performance comparisons. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801378n [article] An experimental study of the GAMS/AlphaECP MINLP solver [texte imprimé] / Toni Lastusilta, Auteur ; Michael R. Bussieck, Auteur ; Tapio Westerlund, Auteur . - 2009 . - pp. 7337–7345. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7337–7345 Mots-clés : Mixed-integer  nonlinear  programming  problems  General  algebraic  modeling  system  GAMS/AlphaECP Résumé : The development of methods to solve mixed-integer nonlinear programming (MINLP) problems has given rise to new solvers and improved the current ones. In this Article, the focus is set on the MINLP solvers in the General Algebraic Modeling System (GAMS) and especially GAMS/AlphaECP. In this Article, a comprehensive comparison of the MINLP solvers is made. In June 2007, GAMS introduced new MINLP solvers: CoinBonmin, AlphaECP, and LINDOGlobal. A description of the improvements made in the second half of 2007 to AlphaECP is given, and the performance of the MINLP solvers in GAMS is examined. Furthermore, the performance of AlphaECP for both MINLP and nonlinear programming (NLP) problems is studied, in conjunction with different subsolvers. Two large collections of problems, MINLPLib and GLOBALLib, are used for all solver performance comparisons. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801378n

Large scale production planning in the stainless steel industry / Janne Karelahti in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 4893–4906 Titre : Large scale production planning in the stainless steel industry Type de document : texte imprimé Auteurs : Janne Karelahti, Auteur ; Pekka Vainiomaki, Auteur ; Tapio Westerlund, Auteur Année de publication : 2011 Article en page(s) : pp. 4893–4906 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stainless  steel  industry Résumé : We introduce a new formulation for a cutting stock problem in the stainless steel industry. The formulation extends some previous models developed for the paper industry. In this formulation, mother coils are assumed to have finite lengths, and the widths and lengths of the mother coils are considered variables as well as the lengths of the product coils along with the cutting patterns to be used. To enable reuse of scrap material, the trim loss at the end of a mother coil is preferred and collected into a single coil. Finally, the scattering of an order to multiple mother coils is minimized to facilitate the shipping of the order in a single batch. For numerical solution, the inherently nonlinear problem is transformed to a linear one by a decomposition technique. The procedure is illustrated with numerical examples. The presented model has been successfully utilized in large scale industrial environment as a part of the production planning system developed for Outokumpu Stainless by Accenture. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101376b [article] Large scale production planning in the stainless steel industry [texte imprimé] / Janne Karelahti, Auteur ; Pekka Vainiomaki, Auteur ; Tapio Westerlund, Auteur . - 2011 . - pp. 4893–4906. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 4893–4906 Mots-clés : Stainless  steel  industry Résumé : We introduce a new formulation for a cutting stock problem in the stainless steel industry. The formulation extends some previous models developed for the paper industry. In this formulation, mother coils are assumed to have finite lengths, and the widths and lengths of the mother coils are considered variables as well as the lengths of the product coils along with the cutting patterns to be used. To enable reuse of scrap material, the trim loss at the end of a mother coil is preferred and collected into a single coil. Finally, the scattering of an order to multiple mother coils is minimized to facilitate the shipping of the order in a single batch. For numerical solution, the inherently nonlinear problem is transformed to a linear one by a decomposition technique. The procedure is illustrated with numerical examples. The presented model has been successfully utilized in large scale industrial environment as a part of the production planning system developed for Outokumpu Stainless by Accenture. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101376b