Abstract: A steering control device, a steering control method, and a steering control system according to the present invention determines a rear wheel steering angle control command for returning a rear wheel steering angle to a predetermined steering angle earlier than a front wheel steering angle when steering wheel operation (that is, operation of a steering wheel) shifts from a state of additional turning to a state of cutback turning, in steering control that steers a rear wheel steering angle of a vehicle in opposite-phase with respect to a front wheel steering angle, and outputs the determined rear wheel steering angle control command to a rear wheel steering device, so that hysteresis of a yaw rate is reduced or eliminated, reducing or eliminating a sense of discomfort given to a driver.

Abstract: A communication device calculates a signal travelling time indicating a time period from a first time at which the signal has been transmitted from the communication device, to a second time at which the transmitted signal is expected to arrive at another communication device serving as a communication partner. The communication device retransmits the signal to the another communication device when a retransmission request of the signal is received from the another communication device after the signal has been transmitted to the another communication device, and suspends a retransmission of the signal when the retransmission request is received again from the another communication device before the signal travelling time elapses from the first time.

Abstract: A communication system includes: a terminal apparatus; and a delivery control apparatus configured to deliver automatically electronic mail to the terminal apparatus without waiting for an acquisition request for the electronic mail from the terminal apparatus, when the delivery control apparatus is configured to receive the electronic mail, wherein the delivery control apparatus includes a mail delivery management unit configured to control to suspend or resume automatic delivery of the electronic mail according to a state of a delivery route of the electronic mail or an apparatus located on the delivery route from the delivery control apparatus to the terminal apparatus, and the terminal apparatus includes a reception unit configured to receive the automatically delivered electronic mail.

Abstract: A communication device calculates a signal travelling time indicating a time period from a first time at which the signal has been transmitted from the communication device, to a second time at which the transmitted signal is expected to arrive at another communication device serving as a communication partner. The communication device retransmits the signal to the another communication device when a retransmission request of the signal is received from the another communication device after the signal has been transmitted to the another communication device, and suspends a retransmission of the signal when the retransmission request is received again from the another communication device before the signal travelling time elapses from the first time.