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Showing papers in "Computers & Chemical Engineering in 2006"


Journal ArticleDOI
TL;DR: The main goal of this paper is to provide an up-to-date review of the state-of-the-art in this challenging area of short-term batch scheduling, with a general classification for scheduling problems of batch processes as well as for the corresponding optimization models.

781 citations


Journal ArticleDOI
TL;DR: This paper provides an overview of the state of the art of subspace identification methods for both open-loop and closed-loop systems.

564 citations


Journal ArticleDOI
TL;DR: A new deterministic spatial branch and contract algorithm is proposed for optimizing such systems, in which piecewise under- and over-estimators are used to approximate the non-convex terms in the original model to obtain a convex relaxation whose solution gives a lower bound on the global optimum.

404 citations


Journal ArticleDOI
TL;DR: An overview of currently available methods for state estimation of linear, constrained and nonlinear systems is provided, and the following methods are discussed: Kalman filtering, extended KalMan filtering, unscented Kalman filters, particle filtering, and moving horizon estimation.

315 citations


Journal ArticleDOI
TL;DR: This paper introduces a modification to original DE that enhances the convergence rate without compromising on solution quality and utilizes only one set of population as against two sets in original DE at any given point of time in a generation.

286 citations


Journal ArticleDOI
TL;DR: Comparing the properties of solutions generated by simultaneous approaches to those of classical variational methods, for a variety of problem classes, shows why simultaneous strategies are especially beneficial for dynamic systems with unstable modes, with path constraints and for large-scale, structured problems.

234 citations


Journal ArticleDOI
TL;DR: The focus of most of this paper will be the control of bioreactors (i.e. fermentors) in which a near optimal environment is desired for microorganisms to grow, multiply, and produce a desired product.

209 citations


Journal ArticleDOI
TL;DR: Criteria based on disturbance rejection and system robustness are proposed to assess the performance of PID controllers and the integral gains of the PID controllers are shown to be a good measure for disturbance rejection.

197 citations


Journal ArticleDOI
TL;DR: A genetic algorithm-called BASIC, which is designed to take advantage of well known genetic schemes so as to be able to deal with numerous optimization problems, and provides an opportunity to the genetic operators to be extended with new schemes.

171 citations


Journal ArticleDOI
TL;DR: A novel MILP-based method that addresses the simultaneous optimization of the off-line blending and the short-term scheduling problem in oil-refinery applications and an iterative procedure is proposed to effectively deal with non-linear gasoline properties and variable recipes for different product grades.

170 citations


Journal ArticleDOI
TL;DR: In this article, the authors demonstrate the applicability and usefulness of high-resolution finite volume schemes for the solution of population balance equations (PBEs) in crystallization processes.

Journal ArticleDOI
TL;DR: Although PDA required considerably less computational effort than traditional nonlinear regression, parameter estimates from PDA were less precise and problems are addressed by a new iterative algorithm (iPDA) in which the spline fits are improved using model-based penalties.

Journal ArticleDOI
TL;DR: This paper gives an introduction to and an overview over analysis and design of polynomial control systems using dissipation inequalities, and new results in emerging design problems, like synchronization.

Journal ArticleDOI
TL;DR: Applications of the proposed technique to a simulated continuous stirred tank reactor demonstrate that combining multiple neural networks can give more reliable and earlier diagnosis than a single neural network whether the networks are trained on quantitative data or qualitative trend data.

Journal ArticleDOI
TL;DR: A hierarchical approach to the control system design is presented and traditional regulatory techniques as well as advanced control strategies for batch, semibatch, and continuous reactors are reviewed.

Journal ArticleDOI
TL;DR: It is suggested that more sophisticated turbulence–chemistry interaction models like the EDC model and more Detailed Reaction Kinetics should be used for combustion modeling in steam cracking furnaces under normal firing conditions.

Journal ArticleDOI
TL;DR: This paper focuses on the development of pharmaceutical informatics to support Active Pharmaceutical Ingredient (API) as well as drug product development as case studies to illustrate the various aspects of this infrastructure.

Journal ArticleDOI
TL;DR: In this article, the forward and adjoint methods for sensitivity analysis of differential-algebraic equation (DAE) and time-dependent partial differential equation (PDE) systems are described.

Journal ArticleDOI
TL;DR: An overview of recently developed methods for control and optimization of complex process systems described by multiscale models using examples of thin film growth processes to motivate the development of these methods and illustrate their application.

Journal ArticleDOI
TL;DR: The modeling approach developed and the obtained results suggest that a new conceptual strategy in enterprise management systems consisting of the integration of the financial models of the enterprise with those dealing with the operative area is a must to improve the firm’s performance and its overall earnings and ensuring also healthy cash flow management.

Journal ArticleDOI
TL;DR: A simple identification method based on relay feedback test for stable and unstable first order plus time delay (FOPDT) processes and a two degree of freedom proportional-integral–proportional-derivative (PI–PD) controller based on the loop phase margin and gain margin criteria is proposed.

Journal ArticleDOI
TL;DR: It is shown that the properties presented here achieve significant reduction in the size of the model and the proposed algorithm generates significantly superior solutions than the deterministic approach and the heuristic proposed by Goel and Grossmann (2004).

Journal ArticleDOI
TL;DR: A novel preprocessing algorithm that identifies infeasible assignments and generates tightening constraints for the assignment subproblem is developed, which significantly reduces the number of sequencing subproblems needed to find the optimal solution and prove optimality.

Journal ArticleDOI
TL;DR: The HPPC challenges for both cryogenic and adsorption processes are presented, recent applicable research is summarized, and directions for future research are proposed.

Journal ArticleDOI
TL;DR: This work examines and proposes improvements to the four basic parts of the algorithm used in the inverse method, i.e., the partial differential equation solver routine, calculation of the Jacobian of the computer-simulated elution profiles with respect to the adsorption isotherm parameters, conversion of experimental detector response into individual concentration contributions and screening between different possible adsorptive models.

Journal ArticleDOI
TL;DR: A hierarchical multiscale simulation framework is outlined and experimental data injection into this framework is discussed and the use of such detailed and reduced kinetic models in reactor optimization as an example toward more conventional process design is illustrated.

Journal ArticleDOI
TL;DR: It is shown that the performance and robustness of the delay compensator are significantly better for the non-square systems than that of the squared down systems.

Journal ArticleDOI
TL;DR: Novel approaches based upon multivariate statistical techniques are shown to provide a soft sensor that can estimate the product quality throughout the batch and provide a long-term estimate of the likely cycle time.

Journal ArticleDOI
J. Brian Froisy1
TL;DR: This paper describes the development of an MPC product at AspenTech, with major effort focused on eliminating the need for practitioners to understand control theory, while ensuring that controllers satisfy theoretical requirements.

Journal ArticleDOI
TL;DR: This paper brings forth some key issues for its successful application in these types of problems, including the choice of function approximator and the use of a penalty function to guard against over-extending the value function approximation in the value iteration.