• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1302-1307
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• 2011

The Spiral coil is made considering primary, secondary side coil inductance, turn number, size, thickness, and shielding area with the litz wire-type in case of manufacturing a coil, and at this time, the semi-automation winding machine is used. When deciding on primary and secondary side coil specification and manufacturing a coil, the spiral coil of a specification varied in the various litz wire of a specification is required, and at this time, a difficulty is generated by the manufacture cost, period which during, and failure the manufacture is generated in the coil sample making. A difficulty is in the desired coil quality control of a specification. Since improving the rectifier of the secondary side in order to improve this kind of problem, the range of the coil design and the during the manufacture, various coil manufacture specifications can be comprehensively made.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.158-164
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• 2005

Purpose : We reviewed the therapeutic results of various Duct-Occlud coils(pfm AG, $K{\ddot{o}}ln$, Germany) to evaluate the efficacy of the most-recently modified Duct-Occlud coil(Nit-Occlud) in the transcatheter closure of patent ductus arteriosus(PDA), including large defects more than 4 mm in diameter. Methods : Two hundred and five patients who underwent percutaneous PDA occlusion using Duct-Occlud devices from March 1996 to December 2003 were enrolled and four types of Duct-Occlud [Standard(S), Reinforced(R), Reinforced reverse cone(RR) and Nit-Occlud(N)] were used in this study. The patients were followed up by echocardiogram and physical examination before discharge, one month, six months and 12 months after the procedure. Results : The rate of residual shunt according to the type of Duct-Occlud were as follows : S-54%, R-72%, RR-50%, N-14%(P<0.05 compared with other devices) at one month, S-25%, R-44%, RR-37%, N-0%(P<0.05 compared with other devices) at six months, S-8%, R-8%, RR-4%, N-0%(P<0.05 compared with S and R) at 12 months and later. Nit-Occlud coil showed the complete occlusion of PDA after six months of follow-up, even in 12 patients with relatively large PDA(>4 mm). Conclusion : The transcatheter closure of PDA using Duct-Occlud was an effective treatment and our study revealed that a Nit-Occlud coil which showed higher rate of occlusion even in PDA with large diameters over than 4 mm, was a more effective modality compared to previous devices.

• Journal of the Korean housing association
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• v.14 no.5
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• pp.75-82
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• 2003

In this study, the thermal performance of the room control system is analyzed in terms of control performance, potential for coil expansion and energy consumption through experiments comparing the individual room control system and an existing system. The results of this study show that the existing system is not able to supply design water flow rate and does not accurately maintain the set point temperature in each room. However, the individual room control system can set a room air temperature for each room, for it is able to supply design water flow and accurately control the set point temperature in each room and can reduce the energy consumption compared to the existing system. Moreover, the individual room control system can reduce the number of coil division zone and facilitates the construction process, because it can extend the length of the coil division.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.62-66
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• 2007

A bronchial artery aneurysm is a rare condition, which needs optimal treatment due to the possibility of a life-threatening hemorrhage by rupture. The surgical removal of the aneurysm is the standard treatment. However, there are a few reports of coil embolization with a transcatheter. A 69 year-old man was referred for a further evaluation of a mass in the right hilum on chest radiography. He denied any respiratory symptoms. A chest CT scan showed a $3{\times}3{\times}4.5cm$ sized vascular mass with strong contrast enhancement on the right hilar area that originated from the bronchial artery. On the angiogram, the bronchial artery originated from the descending thoracic aorta at the T8 level. A bronchial artery aneurysm was catheterized selectively. and embolized successfully with a coil. After coil embolization, the selective bronchial arteriography confirmed complete occlusion. We report this case of bronchial aneurysm that was treated successfully with coil embolization.

• Journal of Navigation and Port Research
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• v.32 no.9
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• pp.717-722
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• 2008

We have proposed and demonstrated an gas-flow sensor using optical fiber bragg grating(FEG). The flow sensor has no electronics and no mechanical parts in its sensing part and the structure is th11s simple and immune to electromagnetic interference(EMI). The FEG sensor was consisted qf the sensing element and a coil heater. The metal coil was used to supply the current to the FEG. While some currents supply to the coil, the refractive index of the FEG under the coil is changed and thus the wavelength shift of fiber optic sensor was induced In this work, the wavelength shift according to flow-rate was experimentally studied and was used to evaluate the gas flow-rate in a gas tube. As a result, it was possible to measure the flow-rate in a linear range from 5 to $20{\ell}/min$ with a resolution of approximately $1{\ell}/min$ at the applied currents of 100 mA and 120 mA. The measured sensitivities were $15.3\;pm/\ell/min$ for 100 mA and $20.2\;pm/\ell/min$ for 120 mA.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.52-56
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• 2006

This paper describes the methods for the detection of shorted-turn in the rotor of a cylindrical synchronous generator. A search coil is installed in the air-gap to detect the shorted-turn. The occurrence of a fault in the rotor winding results in a decrease of the induced voltages in the stator. And the magnitude of the rotor flux can be estimated by using the search coil and the estimated stator voltages respectively. And the magnitude of the estimated rotor flux is used for discriminating the rotor windings short or not by detecting the magnitude of the rotor flux. The method using a search coil located in the air-gap can detect not only the occurrence of a turn fault but also its position in the rotor winding. But the method using the estimated stator voltages gives the magnitude of the rotor flux, and only the number of a short-turn.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.723-724
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• 2006

In this study, superconducting coil arrangements and cryostat concept design were conducted for the development of 13.2kV/630A bifilar winding type high temperature superconducting(HTS) fault current limiter(FCL) with YBCO coated conductor(CC) wire. The coil consists of several layers with unique non-inductive solenoid winding method. Six types of HTS coil arrangements were investigated for the optimal insulation design of HTS FCL. And, conceptual design of cryostat was conducted for the decrement of thermal invasion and the prevention of low voltage insulation breakdown in the LHe which is used as pressurization gas in sub-cooling condition of liquid nitrogen(LN2). As the results, it was found that the modified suspended type cryostat with horizontal coil arrangement is beneficial to the insulation design of 13.2kV level bifilar winding type HTS FCL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.84-90
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• 2018

In constructing the multi-body dynamics model to analyze the behavior of the railway vehicle, it is very important to understand the properties of the suspension elements that constitute the suspension system. Among them, coil springs, which are mainly used in primary and secondary suspension systems, clearly show the axial stiffness in the drawings, but the lateral properties of the coil springs are not specified clearly, making it difficult to construct a dynamic analysis model. Therefore, in this paper, the model for analyzing the lateral stiffness of the coil spring is examined. A finite element method was applied to analyze the lateral stiffness of the coil spring and numerical analysis was performed by applying the coil spring lateral stiffness analysis model proposed by Krettek and Sobczak. And the test to analyze the lateral stiffness of coil spring was conducted. As a result of comparing with the test results, it was found that the results obtained by applying the lateral stiffness analysis model of Krettek and Sobczak and correcting the correction coefficient are similar to those of the test results.

• Journal of Applied Reliability
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• v.11 no.2
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• pp.111-126
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• 2011

The clutch coil mounted on the automotive air conditioner is an important part which actuates the clutch to connect or disconnect the pulley and the compressor according to the climate control condition in an automobile. Here, it is generally required that the clutch coil should ensure the long term durability requirement, such as a warranty for the 10 years of field operation or 160,000 km driving, especially in a brand new item, and so forth. However, some difficulties have arisen in restoring its credibility, since domestic specifications for the part have not been yet unified. In order to ensure the reliability, test methods and assessment criteria should be standardized. Moreover, assessed lifetime under specific conditions and potential failure analysis would be important. In this study, lifetime test specifications for the clutch coil have been reviewed and methodological suggestions are provided to ensure reliability, utilizing a quality function deployment through the potential failure mode effect analysis.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.643-651
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• 2006

The theory for a novel fault-tolerant 4-active-pole homopolar magnetic bearing is developed. If any one coil of the four coils in the bearing actuator fail, the remaining three coil currents change via an optimal distribution matrix such that the same opposing pole, C-core type, control fluxes as those of the un-failed bearing are produced. The hompolar magnetic bearing thus provides unaltered magnetic forces without any loss of the bearing load capacity even if any one coil suddenly fails. Numerical examples are provided to illustrate the novel fault-tolerant, 4-active pole homopolar magnetic bearings.