1. S Y S T E M M O N I T O R I N G The use of machine learning techniques in structural and motor monitoring…
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9. Feed Forward Neural Networks 1 1 Input Layer Hidden Layer Output Layer x 1 x n Input vector y 1 y m Output vector The size of the network is usually small: Input vector: 3-20 nodes
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11. Real-world distribution. 0 for class A 1 for class B t=50 t=100 t=150 t=200 Training Architecture of the network Back-Propagation algorithm B A
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13. Kohonen Self Organizing Map (SOM) x 1 x n Input vector To each node of the network is associated a vector in the input space mi 1 mi n When the input vector is presented to the map, its distance to the weight vector of each node is computed. The map returns the closest node which is called the Best Matching Unit. BMU The output of the map is usually sent to another learning machine which will finish the process of pattern recognition.
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15. Kohonen SOM training (example) 10x10 Kohonen Map X 1 X2 X3 Y … ...…………… … ...…………… … ...…………… 0 1 33 Training Set Where Y is the number of short-circuit terms and x1,x2,x3 are the amplitude of specific frequency in the spectrum
16. Kohonen SOM training (example) 10x10 Kohonen Map 0 4 5 6 7 8 9 10 11 13 15 18 19 21 25 23 28 29 29 31 33 X 1 X2 X3 Y … ...…………… … ...…………… … ...…………… 0 1 33 Training Set
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18. Conclusion Despite good results more research needs to be done in system monitoring especially in the case where several faults or damages occur at the same time.