Abstract: Disclosed is a street lamp control system, which cuts off power sources only around an abnormal street lamp where an electric leakage or dangerous situation occurs and allows the rest street lamps to be kept being turned on. The street lamp control system is positioned in a region divided by a plurality of areas where a predetermined number of street lamps are installed. A distribution panel is installed in each center of the areas, and includes two power source control switching circuits for controlling right and left power sources of the corresponding areas. The power source control switching circuit of the corresponding distribution panel turns off the right and left street lamps including the corresponding street lamp when an abnormal state is sensed on a specific street lamp of a specific area, and a power is supplied to the right and left street lamps to be turned on excluding the abnormal street lamp.

Abstract: A method for performing a hard hand-off between service areas in a cellular mobile communication system is provided. The method for performing a hard hand-off according to the invention includes the steps of setting an area of services covered with a frequency assignment (FA) unavailable to adjacent stations to be a boundary cell, entering into the set boundary cell by a mobile communication terminal during communication, and searching FAs of adjacent stations excluding the base station currently engaged in communication with said mobile communication terminal so as to determine a target FA, with which the mobile communication terminal is to perform a hard hand-off. The method for performing a hard hand-off according to the invention can prevent deterioration of call qualities caused by unnecessary hard hand-offs, and reduce the load on a system.

Abstract: An versatile vacuum cleaner is disclosed which comprises a main body, a socket, a first cleaner, a second cleaner, a motor assembly, a cord reel, a handle, and an exhaust duct, and can be converted easily into different configurations each suitable for a specifically different type of vacuum cleaning operation. Improvements are made in details such as the arrangement or the configuration of the main body, the socket, the first cleaner, the second cleaner, the cord reel, the handle, and exhaust duct, thereby improving the operability of the vacuum cleaner and improving the performance thereof.

Abstract: An improved versatile vacuum cleaner is disclosed which comprises a main body, a socket, a first cleaner, a second cleaner, a motor assembly, a cord reel, a handle, and an exhaust duct, and can be converted easily into different configurations each suitable for a specifically different type of vacuum cleaning operation. Improvements are made in details such as the arrangement or the configuration of the main body, the socket, the first cleaner, the second cleaner, the cord reel, the handle, and exhaust duct, thereby improving the operability of the vacuum cleaner and inproving the performance thereof.

Abstract: A method for performing a hard hand-off between service areas in a cellular mobile communication system is provided. The method for performing a hard hand-off according to the invention includes the steps of setting an area of services covered with a frequency assignment (FA) unavailable to adjacent stations to be a boundary cell, entering into the set boundary cell by a mobile communication terminal during communication, and searching FAs of adjacent stations excluding the base station currently engaged in communication with said mobile communication terminal so as to determine a target FA, with which the mobile communication terminal is to perform a hard hand-off. The method for performing a hard hand-off according to the invention can prevent deterioration of call qualities caused by unnecessary hard hand-offs, and reduce the load on a system.

Abstract: A vacuum cleaner having a noise reduction system which can effectively reduce noise is disclosed. The noise reduction system has a casing, a motor cap disposed in the casing such that it can surround a motor, a first sound-absorbing material provided in the inner wall of motor cap, and a second sound-absorbing material provided in the inner wall of the casing. The noise reduction system lengthens the fluid path in the vacuum cleaner so that air can fully contact the first and second sound-absorbing materials, thereby reducing the noise caused by friction between the sucking air and elements of the vacuum cleaner.