Abstract: A DC-DC converter includes a PWM modulator, a power switch and a filter. The PWM modulator positively feeds back a pulse width modulated signal of which a pulse width and a frequency are varied to generate an oscillated signal, amplifies a difference between a negatively fed-back direct current output signal and a reference signal to output a first signal, and compares the first signal with the oscillated signal to generate first and second switching signals. The power switch transfers an input signal to a first output node in response to the first and second switching signals, and generates the pulse width modulated signal, wherein the pulse width modulated signal is provided to the first output node. The filter generates a direct current output voltage signal in response to the pulse width modulated signal, wherein the direct current output voltage signal is provided to a second output node.

Abstract: The object of this invention is to provide a self-expandable stent, made of a shape-memory alloy and used for insertion in a narrow or blocked target portion of the contracted gullet having a lesion so as to open the target portion. The stent includes a coated primary unit having a hollow cylindrical body fabricated by knitting a shape-memory alloy wire to make a net structure, with both an enlarged diameter part and a coat layer. An uncoated secondary unit surrounds the hollow cylindrical body of the coated primary unit. The secondary unit has a hollow cylindrical body fabricated by knitting a superelastic shape-memory alloy wire to make a net structure having diamond-shaped meshes. The stent is prevented from being undesirably removed from a narrow or blocked target portion of the gullet having a lesion.

Abstract: Disclosed herein is a flexible self-expandable stent using shape memory alloy for expanding stenosal portions and method and apparatus for fabricating the same.

Abstract: Disclosed herein is a flexible self-expandable stent using shape memory alloy for expanding stenosal portions and method and apparatus for fabricating the same.

Abstract: In a system for determining a precise orbit of a satellite, a satellite control system includes a tracking, telemetry and command module for receiving telemetry data from the satellite, tracking the satellite, and performing link to the satellite; a satellite operations sub module for extracting L1 carrier phase data by processing the telemetry data, monitoring the satellite, generating telecommand data, and controlling the satellite; and a mission analysis and planning subsystem for determining the precise orbit of the satellite using the L1 carrier phase data collected by a satellite, L1/L2 carrier phase data of the reference ground stations of the GPS satellites collected by an IGS, and a path error caused by the ionosphere of data, and analyzing and planning a mission of the satellite.

Abstract: A stent (5), made of a shape-memory alloy and inserted into a stenosed vessel (50), and a stent foundation device for inserting such a stent (5) into a desired part (52) of the stenosed vessel (50) are disclosed. The stent (5) consists of a net-structural hollow cylindrical body (3) made by knitting one longitudinal superelastic shape-memory alloy wire while repeatedly crossing the wire at various points so as to form a plurality of diamond-shape meshes (2). The stent foundation device consists of an actuation steel core (12), a moveable tube (15) and an insert tube (20), which are received within an outside hollow tube (13) while being axially movable within the outside tube. (13). In the above device, an insert tip (23) is connected to the front end of the insert tube (20). The insert tip (23) has a step (22) forming a fitting end, at which the insert tip (23) is partially fitted into the front end of the outside tube (13) and is connected to the front end of the insert tube (20).

Abstract: Disclosed herein is a flexible self-expandable stent using shape memory alloy for expanding stenosal portions and method and apparatus for fabricating the same.

Abstract: A plasma display device and a driving method thereof are disclosed in which cathodes are provided in the form of steps or in the form of depressions and projections to form multistep discharge gaps between the cathodes and anodes, while amplitude modulated pulses, width modulated pulses, or composite width/amplitude modulated pulses are supplied to the cathode or anodes, the pulse amplitudes for the different steps being set in such a manner that the discharges should occur selectively or wholly at the different discharge regions of the different gaps formed by the cathodes. The device of the present invention improves the gray scale to a great extent.