Abstract: A boundary clock (100) as a time synchronization device according to the present disclosure includes: an offset calculation unit (102) that calculates an offset that is a difference between device internal time of a higher-level device and device internal time of an own device; a transmission delay time calculation unit (103) that calculates a transmission delay time of a packet transmitted and received between the higher-level device and the own device; and a determination unit (111) that determines an occurrence location of a failure in time synchronization with the higher-level device on the basis of the offset and the transmission delay time, and stops synchronization of device internal time of a lower-level device with the device internal time of the own device in a case where it is determined that the occurrence location of the failure is the higher-level device.

Abstract: A measurement instrument (30) according to the present disclosure includes: a UTC acquisition unit (31) configured to acquire a reference time from a satellite signal; a BC time acquisition unit (32) configured to acquire time information regarding an in-device time of a first device (3); a UTC-BC offset calculation processing unit (33) configured to calculate a first offset that is a difference between the reference time and the in-device time of the first device (3) based on the reference time and the time information; a BC-client offset calculation processing unit (34) configured to acquire a copy of the packet and calculate a second offset that is a difference between the in-device time of the first device (3) and the in-device time of the second device (4) based on the acquired packet and a transmission delay between the first device (3) and the second device (4); and a time accuracy calculation processing unit (35) configured to measure accuracy of an in-device time of the second device (4) with respect

Abstract: A system for measuring an in-ash unburned combustibles concentration includes: a storage that stores therein the pieces of characteristic data; and an arithmetic processor including a selector and an in-ash unburned combustibles concentration calculator. The selector selects, from among the pieces of characteristic data stored, a piece of characteristic data whose first reflected light intensity index is the same as, or similar to, the first reflected light intensity index of subject ash. By using the correlation information contained in the piece of characteristic data that has been selected, the in-ash unburned combustibles concentration calculator calculates an in-ash unburned combustibles concentration corresponding to the second reflected light intensity index of the subject ash as the in-ash unburned combustibles concentration of the subject ash.

Abstract: A transfer device (10) transfers a packet between a first network (31) and a second network connected to a network device (32) via a first communication path and a second communication path, the network device (32) functioning as a gateway for connecting to the first network (31). The transfer device (10) includes a control unit (16, 22). The network device (32) holds correspondence information indicating a correspondence relationship between each of a first communication port for connecting to the first communication path and a second communication port for connecting to the second communication path, and address information regarding a destination of the packet. The control unit (16, 22) transmits, to the network device (32), an update control signal for the network device (32) to update the address information associated with the first communication port in the correspondence information.

Abstract: The disclosure has an object to allow local expansion without causing any loop. The disclosure is a system to which two nodes respectively belonging to different ring networks are connected, wherein the two nodes are connected to each other using a predetermined customized port, upon receipt of a predetermined unicast frame, one of the two nodes transmits the frame to another of the two nodes using the customized port, upon receipt of the predetermined unicast frame from the customized port, the other of the two nodes forwards the unicast frame, and upon receipt of a frame different from the predetermined unicast frame from the customized port, the other of the two nodes discards the frame.

Abstract: An object of the present disclosure is to provide a communication system, a communication path switching method, a communication device, and a program capable of continuing communication or shortening a communication disconnection time even during an operation of switching paths. A communication system according to the present disclosure is a communication system including two communication devices forming a duplex path with a common access network.

Abstract: An object is to provide a route switching method, a transfer device, and communication system that can continue communication even during route switching work. In a route switching method according to the present invention, in bypass transfer that transfers a packet while bypassing a non-transferable route, the transfer device having detected the non-transferable route attaches a bypass packet flag to the packet that passes through a non-transferable route and specifies the packet as a bypass packet, the transfer device having detected the non-transferable route returns the bypass packet and transfers the bypass packet in a direction opposite to that of the packet in the ring network, and the transfer device for which the blocked port is set in the ring network transfers the bypass packet through the blocked port before the route switching work.