Documents disponibles écrits par cet auteur

FuelOpt / P. Flisberg in Journal of the operational research society (JORS), Vol. 63 N° 11 (Novembre 2012) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 63 N° 11 (Novembre 2012) . - pp. 1600–1612 Titre : FuelOpt : a decision support system for forest fuel logistics Type de document : texte imprimé Auteurs : P. Flisberg, Auteur ; M. Frisk, Auteur ; M. Rönnqvist, Auteur Année de publication : 2012 Article en page(s) : pp. 1600–1612 Note générale : operational research Langues : Anglais (eng) Mots-clés : practice  of  OR;  transport;  energy;  inventory;  linear  programming Index. décimale : 001.424 Résumé : The use of forest fuel is increasing at heating plants in Sweden. Heating plants provide energy in the form of hot water for heating houses and apartments in local municipalities. Forest fuel are products obtained from harvesting in forests that cannot be used for further processing at sawmills and pulp and paper mills. Examples of such products are tree branches, tree tops and low quality logs. The optimization of the supply chain for round-wood (logs to sawmills, pulp and paper mills) and for forest fuel is similar but involves two main differences. First, forest fuel has to be converted into chips before delivery to the customer, and second, the demand for forest fuel varies over the year due to the temperature. To balance the chipping and transportation capacities over time, it is important to manage inventory levels at terminals. The optimization model developed provides decision support for questions regarding the choice of technology for chipping, where to perform the chipping operations, and the allocation of different assortments to heating plants. The system has been tested on a large case study from a Swedish forest energy company. The results show large savings and that the system is very useful for both planning and business development. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n11/abs/jors2011157a.html [article] FuelOpt : a decision support system for forest fuel logistics [texte imprimé] / P. Flisberg, Auteur ; M. Frisk, Auteur ; M. Rönnqvist, Auteur . - 2012 . - pp. 1600–1612. operational research Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 63 N° 11 (Novembre 2012) . - pp. 1600–1612 Mots-clés : practice  of  OR;  transport;  energy;  inventory;  linear  programming Index. décimale : 001.424 Résumé : The use of forest fuel is increasing at heating plants in Sweden. Heating plants provide energy in the form of hot water for heating houses and apartments in local municipalities. Forest fuel are products obtained from harvesting in forests that cannot be used for further processing at sawmills and pulp and paper mills. Examples of such products are tree branches, tree tops and low quality logs. The optimization of the supply chain for round-wood (logs to sawmills, pulp and paper mills) and for forest fuel is similar but involves two main differences. First, forest fuel has to be converted into chips before delivery to the customer, and second, the demand for forest fuel varies over the year due to the temperature. To balance the chipping and transportation capacities over time, it is important to manage inventory levels at terminals. The optimization model developed provides decision support for questions regarding the choice of technology for chipping, where to perform the chipping operations, and the allocation of different assortments to heating plants. The system has been tested on a large case study from a Swedish forest energy company. The results show large savings and that the system is very useful for both planning and business development. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n11/abs/jors2011157a.html

Parallel Dantzig–Wolfe decomposition of petroleum production allocation problems / E. Torgnes in Journal of the operational research society (JORS), Vol. 63 N° 7 (Juillet 2012) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 63 N° 7 (Juillet 2012) . - pp. 950–968 Titre : Parallel Dantzig–Wolfe decomposition of petroleum production allocation problems Type de document : texte imprimé Auteurs : E. Torgnes, Auteur ; V. Gunnerud, Auteur ; E. Hagem, Auteur ; M. Rönnqvist, Auteur ; B. Foss, Auteur Année de publication : 2012 Article en page(s) : pp. 950–968 Note générale : Operational research Langues : Anglais (eng) Mots-clés : Optimization  Dantzig–Wolfe  Decomposition  Oil  and  gas  Parallel  computing Index. décimale : 001.424 Résumé : This article discusses the optimization of a petroleum production allocation problem through a parallel Dantzig–Wolfe algorithm. Petroleum production allocation problems are problems in which the determination of optimal production rates, lift gas rates and well connections are the central decisions. The motivation for modelling and solving such optimization problems stems from the value that lies in an increased production rate and the current lack of integrated software that considers petroleum production systems as a whole. Through our computational study, which is based on realistic production data from the Troll West field, we show the increase in computational efficiency that a parallel Dantzig–Wolfe algorithm offers. In addition, we show that previously implemented standard parallel algorithms lead to an inefficient use of parallel resources. A more advanced parallel algorithm is therefore developed to improve efficiency, making it possible to scale the algorithm by adding more CPUs and thus approach a reasonable solution time for realistic-sized problems. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n7/abs/jors201162a.html [article] Parallel Dantzig–Wolfe decomposition of petroleum production allocation problems [texte imprimé] / E. Torgnes, Auteur ; V. Gunnerud, Auteur ; E. Hagem, Auteur ; M. Rönnqvist, Auteur ; B. Foss, Auteur . - 2012 . - pp. 950–968. Operational research Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 63 N° 7 (Juillet 2012) . - pp. 950–968 Mots-clés : Optimization  Dantzig–Wolfe  Decomposition  Oil  and  gas  Parallel  computing Index. décimale : 001.424 Résumé : This article discusses the optimization of a petroleum production allocation problem through a parallel Dantzig–Wolfe algorithm. Petroleum production allocation problems are problems in which the determination of optimal production rates, lift gas rates and well connections are the central decisions. The motivation for modelling and solving such optimization problems stems from the value that lies in an increased production rate and the current lack of integrated software that considers petroleum production systems as a whole. Through our computational study, which is based on realistic production data from the Troll West field, we show the increase in computational efficiency that a parallel Dantzig–Wolfe algorithm offers. In addition, we show that previously implemented standard parallel algorithms lead to an inefficient use of parallel resources. A more advanced parallel algorithm is therefore developed to improve efficiency, making it possible to scale the algorithm by adding more CPUs and thus approach a reasonable solution time for realistic-sized problems. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n7/abs/jors201162a.html