Perhaps you should try some spelling variations:
"learning-based a simulation techniques" » "learning-based a imputation techniques", "learning-based a segmentation techniques", "learning-based a inhalation technique", "learning-based _ simulation techniques", "learning-based k simulation techniques", "learning-based n simulation techniques"
"learning-based no2 mitigation techniques" » "learning-based no2 imputation techniques", "learning-based _ mitigation techniques", "learning-based error mitigation techniques", "learning-based co mitigation techniques", "learning-based n mitigation techniques"

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