Documents disponibles écrits par cet auteur

Capacity planning under clinical trials uncertainty in continuous pharmaceutical manufacturing, 1 / Arul Sundaramoorthy in Industrial & engineering chemistry research, Vol. 51 N° 42 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13692–13702 Titre : Capacity planning under clinical trials uncertainty in continuous pharmaceutical manufacturing, 1 : Mathematical framework Type de document : texte imprimé Auteurs : Arul Sundaramoorthy, Auteur ; James M. B. Evans, Auteur ; Paul I. Barton, Auteur Année de publication : 2012 Article en page(s) : pp. 13692–13702 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pharmaceutical  manufacturing Résumé : Unlike traditional batch-based pharmaceutical manufacturing, where the active pharmaceutical ingredient (API) and the final drug product are often produced in different facilities at different locations, novel continuous pharmaceutical manufacturing strategies enable the production of both the API and the final drug product in the same integrated facility. The capacities of such integrated continuous facilities must be determined for potential products in the face of clinical trials uncertainty. Given a portfolio consisting of potential products in the development stage, the goal of capacity planning is to ensure the availability of enough production capacity to meet the projected demands of products, which vary from the launch to the peak-demand periods. To address this problem, we propose a multiscenario, multiperiod, mixed-integer linear programming (MILP) formulation that takes into account uncertainty in the outcome of clinical trials. We illustrate the proposed framework using several examples. The exponential increase in problem size with the number of products motivates us to develop an efficient solution method, which is discussed in Part 2 of this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300324h [article] Capacity planning under clinical trials uncertainty in continuous pharmaceutical manufacturing, 1 : Mathematical framework [texte imprimé] / Arul Sundaramoorthy, Auteur ; James M. B. Evans, Auteur ; Paul I. Barton, Auteur . - 2012 . - pp. 13692–13702. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13692–13702 Mots-clés : Pharmaceutical  manufacturing Résumé : Unlike traditional batch-based pharmaceutical manufacturing, where the active pharmaceutical ingredient (API) and the final drug product are often produced in different facilities at different locations, novel continuous pharmaceutical manufacturing strategies enable the production of both the API and the final drug product in the same integrated facility. The capacities of such integrated continuous facilities must be determined for potential products in the face of clinical trials uncertainty. Given a portfolio consisting of potential products in the development stage, the goal of capacity planning is to ensure the availability of enough production capacity to meet the projected demands of products, which vary from the launch to the peak-demand periods. To address this problem, we propose a multiscenario, multiperiod, mixed-integer linear programming (MILP) formulation that takes into account uncertainty in the outcome of clinical trials. We illustrate the proposed framework using several examples. The exponential increase in problem size with the number of products motivates us to develop an efficient solution method, which is discussed in Part 2 of this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300324h

Controlled formation of nanostructures with desired geometries. 1. robust static structures / Earl O. P. Solis in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 7728–7745 Titre : Controlled formation of nanostructures with desired geometries. 1. robust static structures Type de document : texte imprimé Auteurs : Earl O. P. Solis, Auteur ; Paul I. Barton, Auteur ; George Stephanopoulos, Auteur Année de publication : 2010 Article en page(s) : pp 7728–7745 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanostructures  Geometries  Robust  Static. Résumé : An essential requirement for the fabrication of future electronic, magnetic, optical, and biologically based devices, composed of constituents at the nanometer length scale, is the precise positioning of constituents in the system’s physical domain. The desired nanostructure must be locally stable to a desired level of robustness, which is the basis for the static design problem described in this paper: systematic use of externally imposed controls, realized through point conditions that introduce attractive or repulsive interaction terms in the system potential energy, to ensure a robust desired structure. The locations of the point conditions are found through the solution of a minimum tiling problem. Given these locations, the point condition strengths are found through the solution of combinatorially constrained optimization problems. System ergodicity must be broken to isolate the desired structure from all competing structures in phase space. We illustrate these static problem solution methods with 1- and 2-dimensional example lattice model systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100066v [article] Controlled formation of nanostructures with desired geometries. 1. robust static structures [texte imprimé] / Earl O. P. Solis, Auteur ; Paul I. Barton, Auteur ; George Stephanopoulos, Auteur . - 2010 . - pp 7728–7745. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 7728–7745 Mots-clés : Nanostructures  Geometries  Robust  Static. Résumé : An essential requirement for the fabrication of future electronic, magnetic, optical, and biologically based devices, composed of constituents at the nanometer length scale, is the precise positioning of constituents in the system’s physical domain. The desired nanostructure must be locally stable to a desired level of robustness, which is the basis for the static design problem described in this paper: systematic use of externally imposed controls, realized through point conditions that introduce attractive or repulsive interaction terms in the system potential energy, to ensure a robust desired structure. The locations of the point conditions are found through the solution of a minimum tiling problem. Given these locations, the point condition strengths are found through the solution of combinatorially constrained optimization problems. System ergodicity must be broken to isolate the desired structure from all competing structures in phase space. We illustrate these static problem solution methods with 1- and 2-dimensional example lattice model systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100066v

Controlled formation of nanostructures with desired geometries. 2. robust dynamic paths / Earl O. P. Solis in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 7746–7757 Titre : Controlled formation of nanostructures with desired geometries. 2. robust dynamic paths Type de document : texte imprimé Auteurs : Earl O. P. Solis, Auteur ; Paul I. Barton, Auteur ; George Stephanopoulos, Auteur Année de publication : 2010 Article en page(s) : pp 7746–7757 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanostructures  Geometries  Robust  Dynamic. Résumé : Part 2 of this series addresses the question of how to manipulate in time the positions and intensities of external controls so that a set of self-assembling nanoscale particles can always reach the nanostructure of desired geometry, starting from any random and unknown spatial distribution of the particles. It complements part 1 in which we examined how to position external controls and compute their intensities so that we can ensure that the final nanostructure with the desired geometry corresponds to a local potential energy minimum surrounded by sufficiently high energy barriers to ensure that the nanostructure is statistically robust, i.e., it remains at the desired geometry with an acceptably high probability. The proposed approach for the generation of robust dynamic self-assembly paths is based on a progressive reduction of the system phase space into subsets with progressively smaller numbers of locally allowable configurational states. In other words, it is based on a judicious progressive transition from ergodic to nonergodic subsystems. The subsets of allowable configurations in phase space are modeled by a wavelet-based spatial multiresolution view of the desired structure (in terms of the number of particles). This approach produces a prescription of the optimal control problem where the dynamic self-assembly of particles into the desired nanostructure is governed by the dynamic master equation of statistical mechanics. A genetic algorithm is used to solve the associated optimization problems at each time period and locate the position of the external controls in the physical domain, as well as their intensities over time. The approaches and methods are illustrated with 1- and 2-dimensional lattice example systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000778 [article] Controlled formation of nanostructures with desired geometries. 2. robust dynamic paths [texte imprimé] / Earl O. P. Solis, Auteur ; Paul I. Barton, Auteur ; George Stephanopoulos, Auteur . - 2010 . - pp 7746–7757. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 7746–7757 Mots-clés : Nanostructures  Geometries  Robust  Dynamic. Résumé : Part 2 of this series addresses the question of how to manipulate in time the positions and intensities of external controls so that a set of self-assembling nanoscale particles can always reach the nanostructure of desired geometry, starting from any random and unknown spatial distribution of the particles. It complements part 1 in which we examined how to position external controls and compute their intensities so that we can ensure that the final nanostructure with the desired geometry corresponds to a local potential energy minimum surrounded by sufficiently high energy barriers to ensure that the nanostructure is statistically robust, i.e., it remains at the desired geometry with an acceptably high probability. The proposed approach for the generation of robust dynamic self-assembly paths is based on a progressive reduction of the system phase space into subsets with progressively smaller numbers of locally allowable configurational states. In other words, it is based on a judicious progressive transition from ergodic to nonergodic subsystems. The subsets of allowable configurations in phase space are modeled by a wavelet-based spatial multiresolution view of the desired structure (in terms of the number of particles). This approach produces a prescription of the optimal control problem where the dynamic self-assembly of particles into the desired nanostructure is governed by the dynamic master equation of statistical mechanics. A genetic algorithm is used to solve the associated optimization problems at each time period and locate the position of the external controls in the physical domain, as well as their intensities over time. The approaches and methods are illustrated with 1- and 2-dimensional lattice example systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000778

Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems / Xiang Li in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299 Titre : Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems Type de document : texte imprimé Auteurs : Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur Année de publication : 2012 Article en page(s) : pp. 7287–7299 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimization  Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f [article] Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems [texte imprimé] / Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur . - 2012 . - pp. 7287–7299. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299 Mots-clés : Optimization  Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f

Optimal design and operation of flexible energy polygeneration systems / Yang Chen in Industrial & engineering chemistry research, Vol. 50 N° 8 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4553–4566 Titre : Optimal design and operation of flexible energy polygeneration systems Type de document : texte imprimé Auteurs : Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur Année de publication : 2011 Article en page(s) : pp. 4553–4566 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flexible  energy  Polygeneration  systems Résumé : The optimal design and operation of flexible polygeneration systems using coal and biomass to coproduce power, liquid fuels, and chemicals is studied. In flexible systems, the various product rates change throughout the lifetime of the plant in response to market conditions in different scenarios. A two-stage programming formulation is proposed to optimize simultaneously the design decision variables and the operational decision variables in all scenarios. The optimal product portfolios, equipment capacity usages, and CO2 emissions of flexible polygeneration systems under different market conditions are discussed. In general, flexible polygeneration systems achieve higher net present values than static ones for the same oil price and carbon tax. Higher net present values can be obtained with increasing operational flexibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021267 [article] Optimal design and operation of flexible energy polygeneration systems [texte imprimé] / Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur . - 2011 . - pp. 4553–4566. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4553–4566 Mots-clés : Flexible  energy  Polygeneration  systems Résumé : The optimal design and operation of flexible polygeneration systems using coal and biomass to coproduce power, liquid fuels, and chemicals is studied. In flexible systems, the various product rates change throughout the lifetime of the plant in response to market conditions in different scenarios. A two-stage programming formulation is proposed to optimize simultaneously the design decision variables and the operational decision variables in all scenarios. The optimal product portfolios, equipment capacity usages, and CO2 emissions of flexible polygeneration systems under different market conditions are discussed. In general, flexible polygeneration systems achieve higher net present values than static ones for the same oil price and carbon tax. Higher net present values can be obtained with increasing operational flexibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021267

Optimal design and operation of static energy polygeneration systems / Yang Chen in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

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A plant-wide dynamic model of a continuous pharmaceutical process / Brahim Benyahia in Industrial & engineering chemistry research, Vol. 51 N° 47 (Novembre 2012) 

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