• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.7-14
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• 2014

There has been extensive experience associated with the operation of SGs wherein it was believed, based on NDE, that throughwall tube indications were present within the tubesheet. The installation of the SG tubes usually involves the development of a short interference fit, referred to as the tack expansion, at the bottom of the tubesheet. The tack expansion was usually effected by a hard rolling process and thereafter, in most instance, by the expansion of a urethane plug inserted into the tube end and compressed in the axial direction. The rolling process by its very nature is considered to be intensive with regard to metalworking at the inside surface of the tube and would be expected to lead to higher residual surface stresses. Alternate repair criteria(ARC) in the tack expansion area have been developed and applied to nuclear power plants in USA, however domestic nuclear power plants have not applied ARC for tubes in tubeheet area yet. In consideration of the degradation characteristics of tubes in the Steam Generator tubesheet, this paper suggests ARC application for tubes in the steam generator tubesheet of the domestic nuclear power plants in order to assure life time of the steam generator as well as nuclear power plants.

• 대한한방내과학회지
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• 제41권3호
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• pp.478-486
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• 2020

Objectives: Pressure injury is a common symptom of end-stage cancer, which impact quality of life. This case study reports on use of traditional Korean medicine in an end-stage cancer patient with pressure injury after debridement and local flap. Methods: A pressure injury with debridement and a local flap was treated using herbal medicine, a carbon arc, acupuncture, dressing, and cooperation in plastic surgery. Pressure injury was followed up with photographs. Results: On the 22^nd day of treatment (26 days after the debridement and local flap), redness, swelling, and the condition of pressure injury were all improved. Moreover, the condition of the pressure injury was good without dressing. Conclusions: These results show that traditional Korean medicine may have a positive effect on a pressure injury and improve the quality of life of cancer patients. However, further study is needed to confirm these findings.

• 핵의학기술
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• 제22권1호
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• pp.84-89
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• 2018

Purpose Renin is a proteolytic enzyme synthesized and secreted from epidermal(juxtaglomerular) cells in kidney. Renin acts on the renin substrate angiotensinogen to produce angiotensin I, and then angiotensin II is produced by the action of angiotensin converting enzyme. This causes the adrenal glands to boost blood pressure (vasoconstriction) and promote aldosterone secretion. While Plasma renin activity (PRA) is to test angiotensin I, the active renin concentration (ARC) is a renin test directly. They have different test methods and their own substrates. However, these two methods are sometimes interpreted as the same as a result. The purpose of this study was to evaluate the usefulness of the ARC test by comparing the results between PRA and ARC. Materials and Methods For the diversity of the experiment, 26 samples were requested to test with PRA(TFB company) and ARC(Cisbio company) to other institution. We compared and analyzed PRA(Immunotech company) and ARC(Cisbio company) tests using 28 samples from September $15^{th}$ to October $13^{th}$ in 2017. The statistical analysis method for PRA/ARC evaluated the usefulness using Microsoft Excel program by verifying a correlation analysis of Aldosterone/PRA ratio and a correlation analysis of Aldosterone/ARC ratio and conducting T-test. Results The regression equation of the PRA(Immunotech company)/ARC(Cisbio company), which was tested in the department, was y = 0.0619x + 0.4615 and the correlation coefficient was 0.73. The regression equation of the PRA(TFB company)/ARC(Cisbio company), which was tested in the other institution, was y = 0.0888x + 0.3316 and the correlation coefficient was 0.91. In addition, The regression equation of Aldosterone / PRA ratio and Aldosterone / ARC ratio was y = 0.875x - 11.688 and the correlation coefficient was 0.87. Plus T - test showed no significant difference (P>0.05). Conclusion Both tests showed a strong positive correlation, but this only represents the strength and direction of the relationship between the two tests. Furthermore, the actual results showed somewhat differences. It is presumed that the measured value was influenced by the endogenous renin group mass in the plasma, the condition of the enzyme reaction and the kind of the inhibitor. When the active renin concentration (ARC) test is performed, it is useful to distinguish between the two tests as they are complementary.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.336-341
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• 2002

Recent developments in sensor hardware and in advanced software have made it feasible to consider automating some of the most difficult welding operations. This paper describes some techniques used to automate successfully multipass submerged arc welding operations typically used in pressure vessel manufacture, shipbuilding, production of offshore structures and in pipe mills.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.696-698
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• 2001

This paper considers the research of the hybrid interrupter which adopts both rotating arc and thermal expansion technology. The operating principle of this device depends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. To develope this type of interrupter, we introduced analytical analysis including electromagnetic and arc fluid simulation and experimental analysis including construction of current source generation facility and arc behavior measurements. In this research, the principle of the interrupting techniques are given and analytical and experimental results of hybrid interrupter which is developed by new technology is introduced.

• Journal of Welding and Joining
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• 제23권3호
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• pp.54-60
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• 2005

Tungsten Inert Gas(TIG) welding is today one of the most popular arc welding process because of its high quality welds and low equipment costs. Even if welding productivity increases with welding speed and current, this strategy is limited by the appearance of defects such as undercut and humping bead due to the depressed molten metal. The purpose of this study investigates the effect of He mixing ratio on the characteristics with high current and speed in TIG welding. The conclusions obtained permit to explain the arc start characteristics quantitatively and the maximum welding speed on stable bead formation with He mixing ratio for high current and speed TIG welding observed in experiments. Also through the relation of the maximum arc pressure and surface depression depth at high current and speed TIG welding, it made clear the mechanism of unstable bead formation.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.1-4
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• 2000

This paper addresses a modified arc-length method for the nonlinear finite element analysis of a structure which is loaded in incremental and fixed forces, simultaneously. The main idea of the method is to separate the displacement term by the constant force from that by the incremental force. As the illustrative examples of the applicability of the present algorithm, a parametric study is performed on the nonlinear buckling behavior of composite cylindrical panels under the combined load of the incremented compression and the constant lateral pressure.

• 대한전기학회논문지
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• 제35권11호
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• pp.495-502
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• 1986

The change of the discharge characteristics of the high-pressure sodium (HPS) lamps is investigated over a power source frequency range of 60 Hz to 30, 000 Hz. As the frequency increases, the light and electrical characteristics of the HPS lamps are improved since the re-ignition is not needed due to the constant electron density, and the cathode fall is reduced. But at the certain frequency range, the arc instability called acoustic resonance occurs, and the arc tube is damaged. Regarding these characteristics and the kind of the illuminating system, a proper frequency is selected to operate the HPS lamps. And a new measuring system using a computer and the storage-scope is developed to avoid the error of the ordinary gauges at high frequency power.

• 산업기술연구
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• 제20권B호
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• pp.169-174
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• 2000

The most of metalhalide lamps is what the momentary restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition in proportion to the gaseous pressure. Therefore it takes about ten minutes to restart the metal Halide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 15kV between the both electrodes of lamp. The proposed ignitor has two ignitors. If we connect each ignitor at the both sides, the high voltages of two different frequencies are generated. If so, when the one of the ignitor generates the highest voltage and the other applied to elecrodes of the lamp. In this way, we can restart the lamp with the voltage 15kV, even if the lamp is in the hot condition.

• Journal of Welding and Joining
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• 제24권3호
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• pp.34-41
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• 2006

The CD (Capacitor Discharge) stud welding utilizes the arc heat and pressure to attach the stud to the workpiece, which consists of the arc. ignition, arcing and pressure welding stages. In order to predict the dynamic behavior of the CD stud welding process, mechanical and electrical models are employed in this work. While the mechanical model estimates the duration of each stage, the electrical model predicts the voltage and current waveforms using the RLC circuit. Effects of process parameters such as the electric components and spring force are analyzed through simulation. It is found that the contact resistance and gap between the stud and base metal influence the tip fusing and arcing duration. The calculated results showed reasonably good agreements with the experiment results.