@article{open954, volume = {82}, number = {3}, author = {P R Patnaik}, note = {Copyright of this article belongs to Canadian Society for Chemical Engineering.}, title = {Neural and hybrid neural modelling and control of fed-batch fermentation for streptokinase: Comparative evaluation under nonideal conditions.}, publisher = {wiley}, year = {2004}, journal = {Canadian Journal of Chemical Engineering}, pages = {599--607}, keywords = {streptokinase, fed-batch fermentation, nonideal conditions, hybrid neural network.}, url = {http://crdd.osdd.net/open/954/}, abstract = {Fermentations involving competition between two or more kinds of cells under nonideal conditions show complex profi les that are sensitive to the extra-cellular environment. These fermentations therefore require accurate and rapid on-line data acquisition and control. However, both on-line measurements and modelling are diffi cult and expensive for large bioreactors, thus limiting the usefulness of model-based control. While neural networks offer an alternative, they require extensive training and can be diffi cult to optimize for large arrays. Hybrid networks combining a few neural networks with some mathematical equations offer a good compromise. The possibility of using a hybrid model for simulation-cum-control has been examined here for the fed-batch production of streptokinase. Under noideal conditions, hybrid neural models outperformed both mathematical models and arrays of neural networks, thus suggesting their viability for large-scale fermentation monitoring and control. Les fermentations provoquant une comp{\'e}tition entre deux ou plusieurs sortes de cellules dans des conditions non id{\'e}ales montrent des profi ls complexes qui sont sensibles {\`a} l?environnement extra-cellulaires. Ces fermentations n{\'e}cessitent donc une acquisition et un contr{\^o}le en continu des donn{\'e}es qui soient pr{\'e}cis et rapides. Toutefois, les mesures et la mod{\'e}lisation en continu sont diffi ciles et co{\^u}teuses pour les grands bior{\'e}acteurs, ce qui limite l?utilit{\'e} du contr{\^o}le bas{\'e} sur des mod{\`e}les. Les r{\'e}seaux neuronaux sont une autre possibilit{\'e}, mais ceux-ci n{\'e}cessitent un entra{\^i}nement pouss{\'e} et peuvent {\^e}tre diffi ciles {\`a} optimiser pour de grands dispositifs. Les r{\'e}seaux hybrides combinant r{\'e}seaux neuronaux et {\'e}quations math{\'e}matiques offrent un bon compromis. La possibilit{\'e} d?utiliser un mod{\`e}le hybride pour la simulation et le contr{\^o}le a {\'e}t{\'e} examin{\'e}e dans ce travail pour la production {\`a} alimentation discontinue de streptokinase. Dans des conditions non id{\'e}ales, les mod{\`e}les neuronaux hybrides offrent une meilleure performance que les mod{\`e}les math{\'e}matiques ou les dispositifs de r{\'e}seaux neuronaux, et il pourrait donc s?av{\'e}rer viable pour la surveillance et le contr{\^o}le de fermentation {\`a} grande {\'e}chelle} }