Abstract: A power system circuit apparatus is provided, which includes a first transformer having a Y-Y connection structure and configured to receive and transform three-phase AC power and output the transformed result, a first controlled rectifier configured to rectify an output voltage of the first transformer and output the rectified result; a second transformer having a Y-delta connection structure and configured to receive and transform the three-phase AC power and output the transformed result; a second controlled rectifier configured to rectify an output voltage of the second transformer and output the rectified result; and an output unit configured to add the output of the first controlled rectifier and the output of the second controlled rectifier and output a resultant sum. Accordingly, there is an effect of reducing the output current ripple and thus reducing the loss compared to the related method.

Abstract: An orbit transition apparatus that transitions an orbit of a payload in outer space includes a rotating body, an adapter disposed on a center part of the rotating body for docking a payload, a launch module disposed outside of the rotating body for launching the payload, and a thruster for rotating the rotating body. The launch module may launch the payload to a target orbit.

Abstract: A drone takeoff and landing system according to an embodiment comprises: a drone including a through-hole; and a landing pad including an extension member which can pass through the through-hole, wherein, when the extension member of the landing pad passes through the through-hole of the drone, an eddy current may occur between the through-hole and the extension member to cause magnetic braking of the drone.

Abstract: A projectile landing apparatus for retrieving a projectile includes a plurality of grippers disposed to be spaced apart. The plurality of grippers may include a support, a guide having one side connected to one end of the support, and a shock absorber having one end connected to the other end of the support and having the other end connected to the guide. The plurality of grippers may guide a projectile, buffer a load, and safely retrieve the projectile.

Abstract: A method of optimizing driving of an antenna for communication of an artificial satellite, by controlling a rotation angle of the antenna, according to an embodiment of the disclosure, includes: receiving a basic profile indicating a change in a rotation angle of the antenna such that a center line of the antenna points to a ground station in response to movement of the artificial satellite; determining a processing section with reference to points at which a rotation velocity of the antenna, for the basic profile, is zero; and generating an optimization profile that determines the change in the rotation angle of the antenna by configuring the rotation velocity of the antenna, for the processing section, with a preset optimized rotation velocity.

Abstract: The present invention provides blade structure testing equipment comprising: a mounting jig to which one end of a blade specimen is mounted; a grip member to which the other end of the blade specimen is coupled; and a wire (W) having one end attached to the grip member to apply a tensile force to the blade specimen in a direction at a certain angle with respect to the ground.

Abstract: An integrated hybrid power apparatus provided in a flying body includes a generator including a stator and a rotor, at least one engine disposed adjacent to the generator and including a cylinder, and a cooler configured to cool the generator and the engine and perform water-cooling that allows a coolant to circulate in the generator and the engine.

Abstract: An aerial vehicle having incline-controllable wings, according to one embodiment, can comprise: a body; a thrust part connected to the body and having a propeller and a rotary shaft; and the wings respectively arranged at both sides of the body, and disposed to be spaced from the thrust part. The wings pitch and rotate around a horizontal axis of the body such that the angle of attack of the wings is controlled, and an angle between the rotary shaft of the thrust part and the wing can vary because of the pitching and rotation of the wings.

Abstract: Provided are an igniter-integrated thrust chamber for a rocket engine using a cryogenic fuel and liquid oxygen and a rocket including the thrust chamber. The thrust chamber includes a combustion chamber and a mixing head assembly, which is disposed at one side of the combustion chamber and is integrated with the combustion chamber.

Abstract: An apparatus for determining a precise location including: a plurality of unmanned aerial vehicles each having a first broadband signal module and a global position system GPS receiver attached thereonto and flying in the air; and a terminal provided at a location and determining the location by communication with the first broadband signal modules. In addition, a method for determining a precise location including: respective GPS receivers receiving GPS signals from artificial satellites and detecting locations of each of the plurality of unmanned aerial vehicles, transmiting locations of the unmanned aerial vehicles and distances between the unmanned aerial vehicles and the terminal and determining a location of the terminal using information received from the first broadband signal modules.

Abstract: A power apparatus for integrated cooling includes a housing, a driving section disposed in the housing, a generator disposed in front or in rear of the driving section in the housing to generate electricity by receiving power from the driving section, and a cooling section disposed in front of the generator in the housing to inhale a fluid by receiving the power from the driving section and cool the generator and the driving section, wherein the cooling section is configured to divide the inhaled fluid toward the driving section and the generator to cool the driving section and the generator.

Abstract: Provided is a method of designing a low-pressure chamber that provides a preset air pressure corresponding to a predetermined altitude. The method may include the steps of: calculating a predetermined error range of the preset air pressure, and calculating an amount and types of materials of a getter to be inserted into the low-pressure chamber based on the error range and a total volume of the low-pressure chamber.

Abstract: The present invention relates to an apparatus and a method for simulating a satellite mission operating state.

Abstract: A method according to the present invention comprises the steps of: dividing SAR raw data into one or more sub-aperture data by a predetermined number in an azimuth direction; performing a spectral length extension FFT on the sub-aperture data in the azimuth direction; multiplying the sub-aperture data by a chirp scaling function; performing a range FFT on the sub-aperture data; performing range compression, SRC, and a bulk RCMC on the sub-aperture data; performing an inverse chirp-z transform on the sub-aperture data in a range direction; multiplying the divided sub-aperture data by a predetermined first function; performing an IFFT on the sub-aperture data in the azimuth direction; recombining the sub-aperture data; multiplying the recombined data by a second function and deramping same; performing an azimuth FFT on the recombined data; performing an azimuth IFFT on the recombined data; multiplying the recombined data by a third function and deramping same; performing the azimuth FFT on the recombined data;

Abstract: Provided is a high efficiency long range drone, and more particularly, a high efficiency long range drone capable of increasing flight time and efficiently using power during long range cruising flight by selectively using the power among an engine generator and a battery and applying an auxiliary wing.

Abstract: A fan-in-wing aerial vehicle according to an embodiment may comprise: a fuselage; main wings expending from both sides of the fuselage in the span direction; rotors rotatably mounted inside the main wings, respectively; and opening/closing portions installed on the main wings such that the same can be opened/closed and thereby expose the rotors to the outside or conceal the rotors from the outside, respectively.

Abstract: Provided is a radio source position estimation system including a plurality of radio transmission devices spaced a predetermined distance apart from one another and configured to transmit radio frequency (RF) signals received from an arbitrary radio source and a central radio reception device configured to estimate a position of the radio source using the RF signals received from at least three radio transmission devices.

Abstract: Provided are an artificial satellite and a method of controlling the same. The artificial satellite includes a main body flying along an orbit of a planet, an optical payload arranged on the main body to photograph a ground surface of the planet, and a pair of solar cell panels rotatably arranged on both sides of the main body in a first direction, wherein the first direction and a flight direction of the main body form an acute angle with each other.

Abstract: Provided is a cooler and an engine testing apparatus having the same. The cooler includes a guide unit configured to make a gas flow, a liquid supply unit arranged in the guide unit to supply a liquid into the guide unit, a liquid column guide unit connected to the guide unit and having a column of the liquid, and a liquid storage unit connected to the liquid column guide unit and storing the liquid.

Abstract: A vibration reduction shaft includes a cylindrical outer shaft having an inner hollow portion, in which the outer shaft includes: a first member (110) and a second member (120) which are disposed to be spaced apart from each other in a longitudinal direction of the shaft; and a vibration reduction region (150) which is disposed between the first member and the second member, and multiple connecting members (151), which connect the first member and the second member in an axial direction, are disposed to be spaced apart from one another within the vibration reduction region.