| Title | 
	Neural Network Modeling based XAI of Activated Sludge Process in Wastewater Treatment System for Dissolved Oxygen Control  | 
					
	| DOI | 
	https://doi.org/10.5370/KIEE.2022.71.8.1176 | 
					
	| Keywords | 
	  Neural  Network;  XAI;  Layer-wise  Relevance  Propagation;  Wastewater  Treatment  System;  Activated  Sludge  Process | 
					
	| Abstract | 
	In  this  paper,  we  proposed  Dissolved  Oxygen(DO)  neural  network  model  of  activated  sludge  process  using  XAI(eXplainable  AI)  in wastewater  treatment  system.  To  improve  the  model  performance,  input  water  qualities  are  to  be  reliable  and  have  a  much  influences in  DO  biological  operation.  In    regulations,  COD,  T-N,  T-P,  pH,  SS  of  effluent  are  hourly  to  transmitted  in  Korea  Environment Corporation.  If  these  values  are  exceed  the  legal  standards,  the  penalty  is  given.  Therefore  these  data  are  very  reliable  and  is monitored  by  operators  critically.  So  these  data  is  to  be  inputs  of  DO  neural  network  model.  And  XAI(eXplainable  AI)  is  utilized  to decide  which  input  water  qualities  have  much  influences  in  the  process.  LRP(Layer-wise  Relevance  Propagation)  is  used  among various  XAI(eXplainable  AI)  methods.  NH4,  MLSS,  pH  in  aeration  tank  and  COD,  TN,  TP,  SS  in  secondary  clarifier  are  input candidates  of  model  for  Do  neural  network  modeling.  Using  LRP,  COD,  NH4,  MLSS,  SS  are  decided  to  be  inputs  of  Do  neural network  model. The  validity  of  the  proposed  method  was  proved  by  applying  to  the  DO  neural  network  model  of  activated  sludge  process  which was  developed  in  previous  research.  3  years  hourly  data  was  used  for  modeling  and  estimation.  The  result  show  that  the performance  of  the  proposed  model  was  improved  in  comparison  of  conventional  neural  network  models. In  the  future,  absolute  values  of  weight  in  LRP  will  be  more  considered  because  we  considered  only  the  inputs  orders  of influencing  on  DO  biological  operation.  |