Abstract: A method may include obtaining a first waveform corresponding to a first optical signal received at a first optical receiver via an optical link, and a second waveform profile corresponding to a second optical signal received a second optical receiver. The first waveform profile and the second waveform profile may be combined to form a combined waveform profile. A first reconstructed waveform profile that is an estimate of the first waveform profile and a second reconstructed waveform profile that is an estimate of the second waveform profile may be obtained. The first reconstructed waveform profile and the second reconstructed waveform profile may be combined to form a combined reconstructed waveform profile which may be emulated to obtain an emulated reconstructed waveform profile. A power profile estimation corresponding to the optical ink may be determined based on a comparison between the combined waveform profile and the emulated reconstructed waveform profile.

Abstract: A control method executed by a computer, the control method includes: generating, when specification of a first data table constituting data to be retrieved is received, a data table copy that is a copy of the first data table, and switching the data to be retrieved, from the first data table to the data table copy; and performing a data retrieval process with respect to the data table copy, by controlling any one of a number of the data to be retrieved from the data table copy and a data retrieval interval, based on a load state estimated from a result of the data retrieval process.

Abstract: According to an aspect of an embodiment, operations may include obtaining a first waveform profile corresponding to an optical signal received at an optical receiver via an optical link between the optical receiver and an optical transmitter. The operations may also include obtaining a second waveform profile that is an estimate of the first waveform profile. The second waveform profile may be based on one or more properties of the optical link and may be based on a complex scaling factor that accounts for rotation of the optical signal as the optical signal propagates via the optical link. In addition, the operations may include determining a power profile estimation corresponding to the optical link based on a comparison between the first waveform profile and the second waveform profile.

Abstract: A control method implemented by a computer configured to control a database that includes an aggregate item that records an aggregate value of transaction volume included in transaction data recorded in a blockchain, the control method including: obtaining a plurality of the transaction data recorded in the blockchain; specifying, for each of a plurality of second users who are transaction partners with a first user associated with the aggregate item, a transaction time with the first user on a basis of the plurality of transaction data; classifying the plurality of second users into a plurality of groups on a basis of dissimilarity of the transaction time; and generating the aggregate item for each of the groups in the database.