Patent ID: 11865483
Assignee: NEC CORPORATION
Field: Chemical engineering (Chemistry)
Classification: CPC B  F  A | IPC A  B  F

Claim 5:
6. The computer-implemented state estimation method according to claim 5, comprising:
calculating a correlation value between each of a plurality of pieces of the current information acquired at different time points and retained in the current information storage and the current information acquired in a state where the filter is clean, and a correlation value between the current information acquired at the state estimation practice time point and the current information acquired in the state where the filter is clean; and
determining that cleaning of the filter has been practiced, when the correlation value between the current information acquired at the state estimation practice time point and the current information acquired in the state where the filter is clean, changes to increasing from a decreasing trend of the correlation values between each of the plurality of pieces of the current information acquired at the different time points and retained in the current information storage and the current information acquired in the state where the filter is clean.