Abstract: A wire saw apparatus comprises: a first pulley system from which a wire is withdrawn toward a structure to be cut; a second pulley system into which the wire is introduced from the structure; a first dust collection pipe unit provided to surround the wire between an end part at which surrounding of the structure by the wire ends and a part at which the wire is introduced into the first pulley system; and a second dust collection pipe unit provided to surround the wire between a start part at which surrounding of the structure by the wire starts and a part at which the wire is withdrawn from the second pulley system.

Abstract: A wireless communication system provides an antenna apparatus for the wireless communication system. The antenna apparatus includes a base, a plurality of Yagi-Uda antenna modules disposed in a specific arrangement, a plurality of floating metal modules correspondingly installed in upper portions of the Yagi-Uda antenna modules and selectively connected to a corresponding Yagi-Uda module among the plurality of Yagi-Uda antenna modules, a switching element for selectively switching the floating metal module and the Yagi-Uda antenna module, and a controller for controlling the Yagi-Uda antenna module to comprise a directivity in a desired direction by selectively switching the switching element.

Abstract: Disclosed is a millimeter wave antenna for diagonal radiation. A first metal layer and a second metal layer having a form of microstrip wire are coated on the bottom surface and at least a partial region of the top surface of a dielectric substrate, respectively. When viewed in a direction perpendicular to the top surface of the dielectric substrate, the second metal layer is covered by the first metal layer. The microstrip wire of the second metal layer may have a length of more than half of a wavelength of a RF signal. The long-wire antenna has a radiation pattern in upward diagonal direction when a signal to transmit is fed under a condition that the first metal layer is grounded. The form of the second metal layer may be a straight line, Y-shape, ?-shape, or etc. An impedance matching metal layer may be added to the second metal layer.

Abstract: An antenna device in a wireless communication includes antenna wires of four sides which include three feeding points and have a loop structure and four main switches which are located among the antenna wires of the four sides, wherein the antenna device operates as a loop antenna when the antenna wires of the four sides are connected according to operations of the main switches and wherein the antenna device operates as dipole antennas when the antenna wires of the four sides are disconnected according to operations of the main switches.

Abstract: An OOK modulation device according to the present inventive concept includes: an oscillator outputting a first frequency signal in which the frequency varies according to an input voltage; a frequency multiplier switching unit operating according to an OOK input data and switching on/off a second frequency signal that is obtained by multiplying the first frequency signal; and a switching amplifying unit amplifying and switching the second frequency signal according to the OOK input data to output an OOK modulation signal.

Abstract: An OOK modulation device according to the present inventive concept includes: an oscillator outputting a first frequency signal in which the frequency varies according to an input voltage; a frequency multiplier switching unit operating according to an OOK input data and switching on/off a second frequency signal that is obtained by multiplying the first frequency signal; and a switching amplifying unit amplifying and switching the second frequency signal according to the OOK input data to output an OOK modulation signal.

Abstract: A wireless communication system provides an antenna apparatus for the wireless communication system. The antenna apparatus includes a base, a plurality of Yagi-Uda antenna modules disposed in a specific arrangement, a plurality of floating metal modules correspondingly installed in upper portions of the Yagi-Uda antenna modules and selectively connected to a corresponding Yagi-Uda module among the plurality of Yagi-Uda antenna modules, a switching element for selectively switching the floating metal module and the Yagi-Uda antenna module, and a controller for controlling the Yagi-Uda antenna module to comprise a directivity in a desired direction by selectively switching the switching element.

Abstract: An antenna device in a wireless communication includes antenna wires of four sides which include three feeding points and have a loop structure and four main switches which are located among the antenna wires of the four sides, wherein the antenna device operates as a loop antenna when the antenna wires of the four sides are connected according to operations of the main switches and wherein the antenna device operates as dipole antennas when the antenna wires of the four sides are disconnected according to operations of the main switches.