Adaptive self-organizing map using optimal control

The self-organizing map (SOM), which is a type of artificial neural network (ANN), was formulated as an optimal control problem. Its objective function is to minimize the mean quantization error, and the state equation is the weight updating equation of SOM. Based on the objective function and the s...

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Main Authors: Alkawaz, Ali Najem, Kanesan, Jeevan, Badruddin, Irfan Anjum, Kamangar, Sarfaraz, Hussien, Mohamed, Baig, Maughal Ahmed Ali, Ahammad, N. Ameer
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Published: MDPI 2023
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Online Access:http://eprints.um.edu.my/38272/
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spelling my.um.eprints.382722023-06-23T02:25:55Z http://eprints.um.edu.my/38272/ Adaptive self-organizing map using optimal control Alkawaz, Ali Najem Kanesan, Jeevan Badruddin, Irfan Anjum Kamangar, Sarfaraz Hussien, Mohamed Baig, Maughal Ahmed Ali Ahammad, N. Ameer TJ Mechanical engineering and machinery TK Electrical engineering. Electronics Nuclear engineering The self-organizing map (SOM), which is a type of artificial neural network (ANN), was formulated as an optimal control problem. Its objective function is to minimize the mean quantization error, and the state equation is the weight updating equation of SOM. Based on the objective function and the state equations, the Hamiltonian equation based on Pontryagin's minimum principle (PMP) was formed. This study presents two models of SOM formulated as an optimal control problem. In the first model, called SOMOC1, the design is based on the state equation representing the weight updating equation of the best matching units of the SOM nodes in each iteration, whereas in the second model, called SOMOC2, it considers the weight updating equation of all the nodes in the SOM as the state updating equation. The learning rate is treated as the control variable. Based on the solution of the switching function, a bang-bang control was applied with a high and low learning rate. The proposed SOMOC2 model performs better than the SOMOC1 model and conventional SOM as it considers all the nodes in the Hamiltonian equation, and the switching function obtained from it is influenced by all the states, which provides one costate variable for each. The costate determines the marginal cost of violating the constraint by the state equations, and the switching function is influenced by this, hence producing a greater improvement in terms of the mean quantization error at the final iteration. It was found that the solution leads to an infinite order singular arc. The possible solutions for the suitable learning rates during the singular arc period are discussed in this study. MDPI 2023-04 Article PeerReviewed Alkawaz, Ali Najem and Kanesan, Jeevan and Badruddin, Irfan Anjum and Kamangar, Sarfaraz and Hussien, Mohamed and Baig, Maughal Ahmed Ali and Ahammad, N. Ameer (2023) Adaptive self-organizing map using optimal control. Mathematics, 11 (9). ISSN 2227-7390, DOI https://doi.org/10.3390/math11091995 <https://doi.org/10.3390/math11091995>. 10.3390/math11091995
institution Universiti Malaya
building UM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaya
content_source UM Research Repository
url_provider http://eprints.um.edu.my/
topic TJ Mechanical engineering and machinery
TK Electrical engineering. Electronics Nuclear engineering
spellingShingle TJ Mechanical engineering and machinery
TK Electrical engineering. Electronics Nuclear engineering
Alkawaz, Ali Najem
Kanesan, Jeevan
Badruddin, Irfan Anjum
Kamangar, Sarfaraz
Hussien, Mohamed
Baig, Maughal Ahmed Ali
Ahammad, N. Ameer
Adaptive self-organizing map using optimal control
description The self-organizing map (SOM), which is a type of artificial neural network (ANN), was formulated as an optimal control problem. Its objective function is to minimize the mean quantization error, and the state equation is the weight updating equation of SOM. Based on the objective function and the state equations, the Hamiltonian equation based on Pontryagin's minimum principle (PMP) was formed. This study presents two models of SOM formulated as an optimal control problem. In the first model, called SOMOC1, the design is based on the state equation representing the weight updating equation of the best matching units of the SOM nodes in each iteration, whereas in the second model, called SOMOC2, it considers the weight updating equation of all the nodes in the SOM as the state updating equation. The learning rate is treated as the control variable. Based on the solution of the switching function, a bang-bang control was applied with a high and low learning rate. The proposed SOMOC2 model performs better than the SOMOC1 model and conventional SOM as it considers all the nodes in the Hamiltonian equation, and the switching function obtained from it is influenced by all the states, which provides one costate variable for each. The costate determines the marginal cost of violating the constraint by the state equations, and the switching function is influenced by this, hence producing a greater improvement in terms of the mean quantization error at the final iteration. It was found that the solution leads to an infinite order singular arc. The possible solutions for the suitable learning rates during the singular arc period are discussed in this study.
format Article
author Alkawaz, Ali Najem
Kanesan, Jeevan
Badruddin, Irfan Anjum
Kamangar, Sarfaraz
Hussien, Mohamed
Baig, Maughal Ahmed Ali
Ahammad, N. Ameer
author_facet Alkawaz, Ali Najem
Kanesan, Jeevan
Badruddin, Irfan Anjum
Kamangar, Sarfaraz
Hussien, Mohamed
Baig, Maughal Ahmed Ali
Ahammad, N. Ameer
author_sort Alkawaz, Ali Najem
title Adaptive self-organizing map using optimal control
title_short Adaptive self-organizing map using optimal control
title_full Adaptive self-organizing map using optimal control
title_fullStr Adaptive self-organizing map using optimal control
title_full_unstemmed Adaptive self-organizing map using optimal control
title_sort adaptive self-organizing map using optimal control
publisher MDPI
publishDate 2023
url http://eprints.um.edu.my/38272/
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score 13.211869