Abstract: An underwater acoustic communication system includes a transmission device including N transmitters, and a reception device. The reception device includes M (M is an integer of two or more) receivers configured to receive M reception signal sequences corresponding to N transmission signal sequences transmitted from the N transmitters through sound waves, a beam former configured to suppress multipath waves other than direct waves of the M received reception signal sequences and to generate L (L is an integer of two or more) signal sequences from the M reception signal sequences, and a signal estimation unit configured to estimate the N transmission signal sequences based on the L generated signal sequences.

Abstract: A method, for controlling a mixer that mixes materials through rotation of an impeller while a solvent contained in the materials is evaporated under negative pressure, performs a process in which the mixer is operated while the pressure inside the mixer is increased or decreased according to a predetermined profile. When a power value of the impeller exceeds a predetermined upper limit during the operation of the mixer, the pressure inside the mixer is increased. When the power value falls below a predetermined lower limit during the operation of the mixer, the pressure inside the mixer is decreased.

Abstract: A method for producing an electrostatic image developing toner includes mixing toner particles containing an amorphous resin with additive particles. A mixing device used in the mixing includes a stirring vessel, a stirring blade, and a jacket configured to cool the stirring vessel, and condition (1) and condition (2) are satisfied. Condition (1): an internal temperature Ti of the mixing device in the mixing and a glass transition temperature Tg of the amorphous resin contained in a near-surface portion of the toner particles satisfy Tg?50° C.?Ti<Tg (inequality 1). Condition (2): 0.08? (Pm?P0)/w?0.50 (inequality 2) is satisfied. In inequality 2, Pm represents an average power (kW) of a motor for driving the stirring blade of the mixing device in the mixing, P0 represents an idling power (kW) of the motor, and w represents a total mass (kg) of the toner particles and the additive particles in the mixing device.