The system acknowledges that each video has been scanned by adding it to the list of outstanding videos for the customer. The system displays the current outstanding balance.
系统通过扫描每盘录像带，将可出租的录像带加入到用户可见的列表中，并显示当前的可出租的录像带列表。
2
The authors propose an additional control strategy, which changes the power or current order according to the variation of system frequency, thus the power balance of the grid can be implemented.