Abstract: A device for ventilating a burning building that includes, a chassis; and a cutting assembly, mounted on the chassis. The cutting assembly is adapted to cut a ventilation hole in a roof or wall member of a building either autonomously or under remote control by an operator to allow smoke and/or hot gases to escape from the roof space.
Abstract: Disclosed is a method of registering only an authorized optical network terminal among a plurality of optical network terminals with the same serial number, in an optical line terminal, using a public key encryption algorithm, in a Gigabit Passive Optical Network (GPON). According to an exemplary aspect, a GPON system encrypts a physical layer OAM message transmitted/received for serial number registration of an optical network terminal, using a key distributed according to a public key encryption algorithm, and authenticates registration of the optical network terminal using the encrypted physical layer OAM message. Accordingly, it is possible to securely authenticate registration of an authorized optical network terminal and block registration of unauthorized optical network terminals.
Type:
Grant
Filed:
July 16, 2009
Date of Patent:
February 3, 2015
Assignee:
Electronics and Telecommunications Research Institute
Inventors:
Kwang-ok Kim, Geun-yong Kim, Dong-soo Lee
Abstract: A feed apparatus has a ball screw, a nut, a drive motor, a braking mechanism and a controller and moves a movable body vertically. When recognizing a movement command for rapid traverse relating to the movable body, the controller, when the movable body is to be moved upward, moves the movable body past a target position according to the movement command and then reverses the moving direction thereof and moves the movable body to the target position and stops it there, and, when the movable body is to be moved downward, moves the movable body directly to the target position and stops it there. After moving the movable body to the target position and stopping it there, the controller causes the drive motor to keep the position of the movable body at the stop position and causes the braking mechanism to brake the movement of the movable body.
Abstract: A post driver which is mounted to the three-point hitch of a tractor is provided with a support to reduce wobble of the post driver during operation and to facilitate mounting of the post driver to the tractor's three-point hitch. The post driver has a carriage and a ram movable vertically relative to said carriage. The carriage is mounted to a base. The base includes a mount adapted for mounting the post driver to a hitch of a vehicle. A support frame depends from the mount rearwardly of the carriage. The frame has a vertical member and a horizontal member, and generally vertically extending legs at the ends of the horizontal member. The legs are mounted to the horizontal member to be movable vertically relative to the horizontal member. The legs are spaced equidistantly from the carriage of the post driver.