Author(s):  
Gustavo B. Libotte ◽  
Fran S. Lobato ◽  
Gustavo M. Platt ◽  
Francisco D. Moura Neto

The determination of optimal feeding profile of fed-batch fermentation requires the solution of a singular optimal control problem. The complexity in obtaining the solution to this singular problem is due to the nonlinear dynamics of the system model, the presence of control variables in linear form and the existence of constraints in both the state and control variables. Traditionally, during the optimization process, uncertainties associated with design variables, control parameters and mathematical model are not considered. In this contribution, a systematic methodology to evaluate uncertainties during the resolution of a singular optimal control problem is proposed. This approach consists of the Multi-objective Optimization Differential Evolution algorithm associated with Effective Mean Concept. The proposed methodology is applied to determine the feed substrate concentration in fed-batch penicillin fermentation process. The robust multi- objective singular optimal control problem consists of maximizing the productivity and minimizing the operation total time.


1970 ◽  
Vol 16 (1) ◽  
pp. 36-56 ◽  
Author(s):  
Roland W. Wood

New approaches to and programs for the treatment of drug addiction are being developed; changes in state and federal drug laws are rapid and are accompanied by bursts of confusion that signal both public acceptance and fear. Basic punitive attitudes toward drug addiction and the drug addict are being reviewed. The question of crime vs. disease is obsolete; addiction must be evaluated as a process rather than as a singular problem. A series of alternative solutions must be generated to deal with the process effectively. New legal struc tures and programs must be designed to deal with the addict in his environment rather than in traditional correctional and hos pital settings. The significant issue is public vs. private care and its effec tiveness. A certain amount of control in treating the addict is necessary, whether this be legal or social; however, only that amount of control necessary to provide stability should be sought. Public programs are a necessity and, for the present, will most likely meet the major need. Private resources must be encouraged and developed and not stifled by the state agency. A full spectrum of services must be supported. The major public programs that have been developed throughout the United States are in keeping with the trends mentioned, in both a legal and a program framework. Of major interest are the federal program of 1966 and the state programs in New York, Califor nia, New Jersey, and Illinois.


2017 ◽  
Vol 90 (4) ◽  
pp. 2797-2812 ◽  
Author(s):  
Marat Akhmet ◽  
Sabahattin Çağ
Keyword(s):  

2011 ◽  
Vol 11 (2) ◽  
pp. 192-205
Author(s):  
Christian Grossmann ◽  
Lars Ludwig ◽  
Hans-Görg Roos

Abstract In the present paper we analyze linear finite elements on a layer adapted mesh for a boundary value problem characterized by the overlapping of a boundary layer with a singularity. Moreover, we compare this approach numerically with the use of adapted basis functions, in our case modified Bessel functions. It turns out that as well adapted meshes as adapted basis functions are suitable where for our one-dimensional problem adapted bases work slightly better.


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