Before revision:  Besides, to attract more customers to participate in the crowdsourcing FL  , we design an incentive mechanism , which awards participants with coins that can be used to purchase other services provided by the company .
After revision:  To protect customers' privacy and improve the test accuracy, we enforce differential privacy on the extracted features and propose a new normalization technique. We experimentally demonstrate that our normalization technique outperforms batch normalization when features are under differential privacy protection. In addition, to attract more customers to participate in the crowdsourcing FL , we design an incentive mechanism , which awards participants with coins that can be used to purchase other services provided by the company .