• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.22-31
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• 2006

When ironwork, especially steel roll coil, is transported to customers, land transportation and sea transportation are usually used. To transport steel roll coil fast and safe without damaging it, it is necessary that the steel roll coil has to be in stable condition. These days, apitong, which is all imported from overseas, is being used to support the steel roll coil, but because of apitong's rigidity, it damages the coil and when the coil is damaged, it is hard to fix. Due to the fact that recovering damage of the coil is almost impossible, we have to find the new type of dunnage that can substitute the apitong. In this paper, the arrays and the kinds of reinforcements, and rectangular type and trapezoid of dunnage will be talked about. The phenomenon of rolling and the impact when the carrier start moving and stop will be talked about as well. Therefore, we are going to develop a dunnage that does not damage ironwork and has better recovery and softness than existing apitong dunnage.

• 전기의세계
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• v.43 no.5
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• pp.36-43
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• 1994

본문에서는 EML의 역사, 종류와 대강에 대해 설명하고, 필자가 미국에서 직접 연구에 참여한 linear induction type coil gun에 대해 간단히 언급하기로 한다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.328-335
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• 2009

In order to 1ransport the steel roll coil effectively and safely to the destination, the stability of the steel roll coil which induced the minimum movements during the 1ransportation was s1rongly required. The basic 1ransportation equipment for the steel roll coil such as the wedge is made of 100% imported wood known as the apitong. However, the material characteristic such as the rigidity has caused permanent damages to the steel roll coil and the damaged steel roll coils were not easily restorable. Thus it was unsuitable for other purposes. The introduction of new materials to manufacturing wedges which would have a good recovery performance and thus enable the wedge prevention or reduction to the steel roll coil or any other products during the 1ransportation is needed. Due to the fact that recovering damage of the coil is almost impossible, we have to find the new type of wedge that can substitute the apitong wedge. Therefore, we are going to develop a wedge that does not damage rolled steel coil and has better recovery and softness than existing apitong wedge.

• Journal of Korean Neurosurgical Society
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• v.43 no.1
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• pp.41-44
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• 2008

Even though intracerebral hematoma (ICH) due to ruptured cerebral aneurysm has been treated by aneurysm clipping at the same time of removal of ICH through craniotomy, such management strategy is controversial in an aged patients with poor clinical grade. In this regards, stereotactic aspiration of hematoma following coil embolization can be an alternative treatment modality. Thus, the authors report a case of an aged patient who underwent stereotactic aspiration of ICH following coil embolization for the ruptured aneurysm with a brief review of literature.

• Laser Solutions
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• v.12 no.2
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• pp.26-30
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• 2009

Scanning Electron Microscopy (SEM) includes high voltage generator, electron gun, column, secondary electron detector, scan coil system and image grabber. Column includes electron lenses (condenser lens and objective lens). Condenser lens generates fringe field, makes focal length and control spot size. Focal length represents property of lens. Objective lens control focus. Most of the electrons emitted from the filament, are captured by the anode. The portion of the electron current that leaves the gun through the hole in the anode is called the beam current. Electron beam probe is called the focused beam on the specimen. Because of the lens and aperture, the probe current becomes smaller than the beam current. It generate various signals(backscattered electron, secondary electron) in an interaction with the specimen atoms. In this paper, we describe the result of research to develop the core elements for low-resolution SEM.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1950-1951
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• 2007

본 논문에서는 코일건의 설계시 자기차폐 효과에 따른 코일건 성능 향상 및 최적화에 대하여 연구하였다. 일반적인 솔레노이드 코일건과 솔레노이드 코일에 자기차폐시킨 코일건의 자기장 분포를 유한요소해석을 통해 비교함으로써 자기차폐를 한 코일건의 자속밀도와 투사체가 받는 힘이 향상됨을 알 수 있었다. 또한 자기차폐시킨 코일건을 동일 코일량에 대한 성능 최대화를 위해 솔레노이드 형상을 최적화하고, 그 모델을 실제 제작하여 성능을 검증하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.277-281
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• 2007

We investigated fault current limitation characteristics of the resistive superconducting fault current limiter (SFCL) which consisted of a Bi-2212 bulk coil and a shunt coil. The Bi-2212 bulk coil and the shunt coil were connected in parallel. The Bi-2212 bulk coil was placed inside the shunt coil to induce field-assisted quench. The fault test was conducted at an input voltage of $200V_{rms}$ and fault current of $12kA_{rms}\;and\;25kA_{rms}$. The fault conditions were asymmetric and symmetric, and the fault period was 5 cycles. The test results show that the SFCL successfully limited the fault current of $12kA_{rms}\;and\;25kA_{rms}$ to below $5.5{\sim}6.9kA_{peak}\;within\;0.64{\sim}2.17$ msec after the fault occurred. Limitation was faster under symmetric fault test condition due to the larger change rate of current. We concluded that the speed of fault current limitation was determined by the speed of current rise rather than the amplitude of a short circuit current. These results show that the Bi-2212 bulk coil is suitable for distribution-class SFCLS.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1998-1999
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• 2007

Before applying the HTS(High Temperature Superconductor) power devices to a real utility network, system analysis should be carried out by some simulation tools. PSCAD/EMTDC simulation tool is one of the most popularized useful analysis tools for electrical power system. Unfortunately the model component for HTS coil is not provided in PSCAD/EMTDC simulation tool. In this paper, EMTDC model component for HTS coil has been developed considering real characteristics of HTS coil like critical current, temperature and magnetic field. The developed model component of HTS coil could be used for power system application. Using the developed model component for HTS coil, we can easily do the simulation of HTS power devices application test in utility with the various inductance, quench current, inner magnetic field, and temperature values, for instances; SMES(Superconducting Magnetic Energy Storage) system, superconducting motor, transformer, and FCL(Fault Current Limiter)

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.639-640
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• 2006

We investigated fault current limitation characteristics of the resistive superconducting fault current limiter(SFCL) which consisted of a Bi-2212 bulk coil and a shunt coil. The Bi-2212 bulk coil and the shunt coil were connected in parallel. The Bi-2212 bulk coil was placed inside the shunt coil to induce field-assisted quench. The fault test was conducted at an input voltage of 200 $V_{rms}$ and fault current of 12 $kA_{rms}$ and 25 $kA_{rms}$. The fault conditions were asymmetric and symmetric, and the fault period was 5 cycles. The test results show that the SFCL successfully limited the fault current of 12 $kA_{rms}$ and 25 $kA_{rms}$ to below $5.5{\sim}6.9kA_{peak}$ within $0.64{\sim}2.17$ msec after the fault occurred. Limitation was faster under symmetric fault test condition due to the larger change rate of current. We concluded that the speed of fault current limitation was determined by the speed of current rise rather than the amplitude of a short circuit current. These results show that the Bi-2212 bulk coil is suitable for distribution-class SFCLs.

• Journal of Magnetics
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• v.21 no.3
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• pp.374-378
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• 2016

The transformer used in an inverter type arc welding machine is designed to use high frequency in order to reduce its size and cost. Also, selecting core materials that fit frequency is important because core loss increases in a high frequency band. An inrush current can occur in the primary coil of transformer during arc welding and this inrush current can cause IGBT, the switching element, to burn out. The transformer design was carried out in $A_P$ method and amorphous core was used to reduce the size of transformer. In addition, sheet coil was used for primary winding and secondary winding coil considering the skin effect. This paper designed the transformer core with an air gap to prevent IGBT burnout due to the inrush current during welding and proposed the optimum air gap length.