Optimisation and control of fed-batch yeast production using q-learning

In this work, the optimal production of yeast with minimal production of ethanol in fed-batch yeast fermentation is investigated. Q-learning (QL) is a heuristic approach suggested for the process dynamic handling to achieve the multiobjective optimisation. The QL agent interacts with the fermentatio...

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Main Author: Helen, Chuo Sin Ee
Format: Thesis
Language:English
English
Published: 2013
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Online Access:https://eprints.ums.edu.my/id/eprint/41805/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/41805/2/FULLTEXT.pdf
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spelling my-ums-ep.418052024-12-04T07:14:36Z Optimisation and control of fed-batch yeast production using q-learning 2013 Helen, Chuo Sin Ee TP1-1185 Chemical technology In this work, the optimal production of yeast with minimal production of ethanol in fed-batch yeast fermentation is investigated. Q-learning (QL) is a heuristic approach suggested for the process dynamic handling to achieve the multiobjective optimisation. The QL agent interacts with the fermentation environment will gain experience on the state transitions, which are represented by the change of substrate, yeast, oxygen and ethanol concentration and the system volume. In the present study, multistep action (MSA) has been implemented in consideration of the inborn process delay for the substrate feeding to take effect on the yeast growth. Parameter deviated model has been implemented in the QL to test the robustness of the algorithm besides to identify the process disturbance. From the result, QL was able to perform multiobjective decision making for the optimal substrate feeding profile. The final yeast production using QL-optimised feeding profile is 20.86% higher compare to the nominal exponential feeding (EF), and 19.59% higher compare to EF with process disturbance. To cater for the process disturbance, Q-learning with exploration (QLE) has been included in this work for online optimisation. QLE signifies the importance of exploration from time to time based on the developed “past experience” in Q-table to optimise the process. The performance of QLE in both nominal and disturbance cases yielded 51.00% and 46.87% higher yeast production than EF respectively, while maintaining low ethanol production. In a nutshell, QL is an alternative that can be considered to perform multiobjective optimisation in a frequently changing bioenvironment and suggest a substrate feeding profile that satisfied the process goal. The QLE can cope better with the process disturbance. 2013 Thesis https://eprints.ums.edu.my/id/eprint/41805/ https://eprints.ums.edu.my/id/eprint/41805/1/24%20PAGES.pdf text en public https://eprints.ums.edu.my/id/eprint/41805/2/FULLTEXT.pdf text en validuser masters Universiti Malaysia Sabah School of Engineering and Information Technology
institution Universiti Malaysia Sabah
collection UMS Institutional Repository
language English
English
topic TP1-1185 Chemical technology
spellingShingle TP1-1185 Chemical technology
Helen, Chuo Sin Ee
Optimisation and control of fed-batch yeast production using q-learning
description In this work, the optimal production of yeast with minimal production of ethanol in fed-batch yeast fermentation is investigated. Q-learning (QL) is a heuristic approach suggested for the process dynamic handling to achieve the multiobjective optimisation. The QL agent interacts with the fermentation environment will gain experience on the state transitions, which are represented by the change of substrate, yeast, oxygen and ethanol concentration and the system volume. In the present study, multistep action (MSA) has been implemented in consideration of the inborn process delay for the substrate feeding to take effect on the yeast growth. Parameter deviated model has been implemented in the QL to test the robustness of the algorithm besides to identify the process disturbance. From the result, QL was able to perform multiobjective decision making for the optimal substrate feeding profile. The final yeast production using QL-optimised feeding profile is 20.86% higher compare to the nominal exponential feeding (EF), and 19.59% higher compare to EF with process disturbance. To cater for the process disturbance, Q-learning with exploration (QLE) has been included in this work for online optimisation. QLE signifies the importance of exploration from time to time based on the developed “past experience” in Q-table to optimise the process. The performance of QLE in both nominal and disturbance cases yielded 51.00% and 46.87% higher yeast production than EF respectively, while maintaining low ethanol production. In a nutshell, QL is an alternative that can be considered to perform multiobjective optimisation in a frequently changing bioenvironment and suggest a substrate feeding profile that satisfied the process goal. The QLE can cope better with the process disturbance.
format Thesis
qualification_level Master's degree
author Helen, Chuo Sin Ee
author_facet Helen, Chuo Sin Ee
author_sort Helen, Chuo Sin Ee
title Optimisation and control of fed-batch yeast production using q-learning
title_short Optimisation and control of fed-batch yeast production using q-learning
title_full Optimisation and control of fed-batch yeast production using q-learning
title_fullStr Optimisation and control of fed-batch yeast production using q-learning
title_full_unstemmed Optimisation and control of fed-batch yeast production using q-learning
title_sort optimisation and control of fed-batch yeast production using q-learning
granting_institution Universiti Malaysia Sabah
granting_department School of Engineering and Information Technology
publishDate 2013
url https://eprints.ums.edu.my/id/eprint/41805/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/41805/2/FULLTEXT.pdf
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