Abstract: A fault management system using a satellite telemetering technology and a method thereof are provided. The fault management system includes: a telemetering sensing unit for collecting telemetering data from target apparatuses, which are installed at a remote location and an unattended location and managed through a satellite, in real time and sensing whether the target apparatuses are malfunctioned or not based on the collected telemetering data; a controlling unit for determining whether the target apparatuses are malfunctioned or not by comparing the telemetering data with unique performance request values for normally driving the target apparatuses, analyzing causes of malfunctions, and storing malfunction data into a malfunction data storing unit; a malfunction data analysis unit for managing the malfunction data stored in the malfunction data storing unit and analyzing the malfunction data; and a display unit for outputting the result of analyzing the malfunction data on a display device.

Abstract: Provided is a voltage controlled oscillator having a new type of a resonator and a negative resistance part capable of finely tuning negative resistance. Thus, the voltage controlled oscillator has an excellent quality factor characteristic and can finely tune the negative resistance even after its fabrication is completed. The voltage controlled oscillator having an active element includes: a resonating unit for generating an oscillation frequency according to a resonance capacitance; a frequency tuning unit, connected to a source terminal of the active element, for tuning the oscillation frequency; and a negative resistance adjusting unit, connected to the frequency tuning unit, for generating a negative resistance to adjust the oscillation frequency, the negative resistance adjusting unit including a varactor diode for finely adjusting the negative resistance.

Abstract: Provided is a voltage controlled oscillator having a new type of a resonator and a negative resistance part capable of finely tuning negative resistance. Thus, the voltage controlled oscillator has an excellent quality factor characteristic and can finely tune the negative resistance even after its fabrication is completed. The voltage controlled oscillator having an active element includes: a resonating unit for generating an oscillation frequency according to a resonance capacitance; a frequency tuning unit, connected to a source terminal of the active element, for tuning the oscillation frequency; and a negative resistance adjusting unit, connected to the frequency tuning unit, for generating a negative resistance to adjust the oscillation frequency, the negative resistance adjusting unit including a varactor diode for finely adjusting the negative resistance.

Abstract: A fault management system using a satellite telemetering technology and a method thereof are provided. The fault management system includes: a telemetering sensing unit for collecting telemetering data from target apparatuses, which are installed at a remote location and an unattended location and managed through a satellite, in real time and sensing whether the target apparatuses are malfunctioned or not based on the collected telemetering data; a controlling unit for determining whether the target apparatuses are malfunctioned or not by comparing the telemetering data with unique performance request values for normally driving the target apparatuses, analyzing causes of malfunctions, and storing malfunction data into a malfunction data storing unit; a malfunction data analysis unit for managing the malfunction data stored in the malfunction data storing unit and analyzing the malfunction data; and a display unit for outputting the result of analyzing the malfunction data on a display device.

Abstract: A duplex stainless steel consisting of a ferrite phase and an austenite phase is disclosed which is superior in the hot ductility, the high temperature oxidation resistance, the corrosion resistance and the impact toughness. The duplex stainless steel is applied to marine facility and the like. The duplex stainless steel which consists of a ferrite phase and an austenite phase is composed of in weight %: less than 0.03% of C, less than 1.0% of Si, less than 2.0% of Mn, less than 0.04% of P, less than 0.004% of S, less than 2.0% of Cu, 5.0-8.0% of Ni, 22-27% of Cr, 1.0-2.0% of Mo, 2.0-5.0% of W, and 0.13-0.30% of N. Or there are further added one or two elements selected from a group consisting of: less than 0.03% of Ca, less than 0.1% of Ce, less than 0.005% of B and 0.5% of Ti. Further, the ratio (Cr.sub.eq /Ni.sub.eq) of the Cr equivalent (Cr.sub.eq) to the Ni equivalent (Ni.sub.eq) is 2.2-3.0. Further, the weight ratio (W/Mo) of the W to Mo is 2.6-3.4.