Abstract: An apparatus for monitoring a multicast group is provided. The apparatus includes a storage, a receiver and an operation processor. The storage is configured to store first data including a first authenticated message authenticated as being published by a publisher of the multicast group to n-th data including an n-th authenticated message authenticated as being published by the publisher where n is a natural number of 2 or more. The receiver is configured to receive status data including a first propagation message to be delivered to the multicast group. Further, the operation processor is configured to generate monitoring information including status information of the multicast group by using the status data and the first to n-th data.

Abstract: A device in a multicast group includes an encryptor/decryptor, a key storage, a security interface and a data processing requestor. The security interface performs receiving and storing a group key and a publisher key from and in the key storage when the device is registered as a publisher, and receiving and storing the group key from and in the key issuing when the device is registered as a subscriber; receiving a request for encrypting first data from the data processing requestor; determining whether the device is an authorized publisher; and transmitting the first data and the read group key to the encryptor/decryptor when the result of the determining indicates the device is the authorized publisher; receiving a first encrypted data generated by encrypting the first data using the group key; and transmitting the first encrypted data to the data processing requestor.

Abstract: Disclosed is a robot and a control method thereof. The robot includes: a camera configured to acquire a depth image of a specific area; a processor configured to create an elevation map for the specific area based on the depth image, and determine whether a head of a person is in the specific area based on the elevation map. The processor, when determining whether the head of the person is in the specific area, is further configured to partition pixels of the elevation map into floor pixels corresponding to a floor area and non-floor pixels corresponding to a non-floor area using elevation values of the elevation map, set paths through the elevation map with a subset of the non-floor pixels as starting points for the paths, and determine whether the head of the person is in the specific area based on whether the paths converge.

Abstract: A device in a multicast group includes an encryptor/decryptor, a key storage, a security interface and a data processing requestor. The security interface performs receiving and storing a group key and a publisher key from and in the key storage when the device is registered as a publisher, and receiving and storing the group key from and in the key issuing when the device is registered as a subscriber; receiving a request for encrypting first data from the data processing requestor; determining whether the device is an authorized publisher; and transmitting the first data and the read group key to the encryptor/decryptor when the result of the determining indicates the device is the authorized publisher; receiving a first encrypted data generated by encrypting the first data using the group key; and transmitting the first encrypted data to the data processing requestor.

Abstract: An apparatus for monitoring a multicast group is provided. The apparatus includes a storage, a receiver and an operation processor. The storage is configured to store first data including a first authenticated message authenticated as being published by a publisher of the multicast group to n-th data including an n-th authenticated message authenticated as being published by the publisher where n is a natural number of 2 or more. The receiver is configured to receive status data including a first propagation message to be delivered to the multicast group. Further, the operation processor is configured to generate monitoring information including status information of the multicast group by using the status data and the first to n-th data.

Abstract: Disclosed is a robot and a control method thereof. The robot includes: a camera configured to acquire a depth image of a specific area; a processor configured to create an elevation map for the specific area based on the depth image, and determine whether a head of a person is in the specific area based on the elevation map. The processor, when determining whether the head of the person is in the specific area, is further configured to partition pixels of the elevation map into floor pixels corresponding to a floor area and non-floor pixels corresponding to a non-floor area using elevation values of the elevation map, set paths through the elevation map with a subset of the non-floor pixels as starting points for the paths, and determine whether the head of the person is in the specific area based on whether the paths converge.