• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.518-526
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• 2017

Objective : Thromboembolism is the one of the most serious complications that can occur during endovascular coil embolization of cerebral aneurysm. We report on the effectiveness and safety of intra-arterial/intravenous (IA/IV) glycoprotein IIb/IIIa inhibitor (tirofiban) infusion for treating thromboembolism during endovascular coil embolization of cerebral aneurysm. Methods : We performed a retrospective analysis of 242 patients with ruptured or unruptured cerebral aneurysms (n=264) who underwent endovascular coil embolization from January 2011 to June 2014. Thromboembolism occurred in 20 patients (7.4%), including 14 cases of ruptured aneurysms and 6 cases of unruptured aneurysms. The most common site of aneurysms was the anterior communicating artery (n=8), followed by middle cerebral artery (n=6). When we found an enlarged thromboembolism during coil embolization, we tried to dissolve it using tirofiban administered via IA and IV loading ($5{\mu}g/kg$, respectively) for 3-5 minutes followed by IV maintenance ($0.08{\mu}g/kg/min$) for approximately 4-24 hours. Results : In 4 of 5 patients with total vessel occlusion, the vessel was recanalized to Thrombolysis in Cerebral Infarction Perfusion Scale (TICI) grade 3, and in 1 patient to TICI grade 2a. In 2 patients with partial vessel occlusion and 13 patients with minimal occlusion, the vessel recanalized to TICI grade 3. Irrelevant intracerebral hemorrhage was noted in 1 patient (5%), and thromboemboli-related cerebral infarction developed in 5 patients (25%), of which only 1 (5%) was symptomatic. Conclusion : IA/IV infusion and IV maintenance with tirofiban appear to be an effective rescue treatment for thromboembolism during endovascular coil embolization in patients with ruptured or unruptured cerebral aneurysms.

• Journal of Magnetics
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• v.16 no.3
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• pp.312-317
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• 2011

NMR over 1 GHz (23.5 T) level has difficulties in design and fabrication with only low temperature superconducting (LTS) wire because of its material characteristics such as the decay of critical current under the magnetic field. Because High temperature superconducting (HTS) tape has a good performance under the extremely high magnetic field, it has been developed for high-field magnet over 23.5 T. In this paper, the LTS magnet was made for applying magnetic fields externally and the HTS coil was designed and fabricated. The electromagnetic field analysis has been done with respect to the structure and the operating current of the LTS and HTS coil. Considering to the field homogeneity and the center field, the design parameters which is suitable for the HTS coil were found. The HTS insert coil was impregnated with epoxy resin in order to prevent the movement of winding during energizing the magnet. The hybrid magnet (LTS/HTS) magnet was fabricated and tested based on the design parameters. The experimental result shows that the LTS background magnet and the HTS insert coil can be operated stable beyond 220 A and 210 A. The final value 4.32 T at the center was acquired.

• Journal of Korean Neurosurgical Society
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• v.61 no.5
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• pp.653-659
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• 2018

Objective : Surgical obliteration of ruptured aneurysm of the proximal posterior inferior cerebellar artery (PICA) is challenging because of limited surgical accessibility. In recent years, coil embolization is the first-choice treatment for these lesions. However, coil embolization is not always easy in ruptured PICA aneurysm owing to the variable anatomical diversity of its shapes, its relationship to the parent artery, its low incidence, and accordingly, lesser neurointerventionist experience. Methods : The parent artery and microcatheter for easier navigation and the embolization technique for stable coiling were identified. Results : This study aimed to identify the more appropriate approach route, microcatheter, and strategies for an easier and safer, and more durable coil embolization in the treatment of lesions in the proximal PICA. Conclusion : Coil embolization for aneurysmal subarachnoid hemorrhage due to a ruptured proximal PICA remains a challenge, but with the appropriate coiling plan, it can be treated successfully.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.130-132
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• 1994

Recently, a Deflection Yoke(DY) is designed in the bobbin-seperator-coil-winding type for high-definite CRT and high-efficient DY of wide vision TV or High Definite TV. This paper presents an optimization or bobbin-seperator-coil-winding type yoke's coil distribution for minimizing gap between desired and practical deflections of electron beams using by Evolution Strategy.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.48-55
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• 2021

The 3-coil magnetic resonance wireless power transmission system was analyzed using an equivalent circuit model, and the |S21| of the system was expressed as the equation of the Q of the three coils, the coupling coefficient k between the transmitting coil and the relay coil, the relay coil and the receiving coil. It is suggested that the maximum efficiency can be obtained when the relay coil is located in the center of the transmitting and the receiving coil. When the distance between the transmitting and the receiving coil is 30 cm and the two coils are aligned, maximum efficiency of 9 % is obtained with the relay coil centered between the coils. If the transmitting coil and the receiving coil are misaligned during a wireless charging of an electric vehicle, the efficiency is expected to decrease significantly compared to the aligned case. It is expected that the efficiency can be increased by using a relay coil and by rotating the coil.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.9
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• pp.714-717
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• 2010

The improved flux-lock type superconducting fault current limiter (SFCL) is composed of a series transformer and superconducting unit of the yttrium-barium-copper-oxide (YBCO) coated conductor. In this paper, we investigated current limiting characteristics through winding direction of coil 2 and variable number of coil 1 and coil 2 in improved flux-lock type SFCL. The better fault current characteristics and the burden of YBCO coated conductor can be confirmed from the experimental result in the higher turn ratio of coil 1 and coil 2 in the additive conditions. In case of subtractive condition, we can confirm a similar result in the same case of experimental conditions. but the burden of YBCO coated conductor has been increased from an increase in winding numbers of coil 2.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.8
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• pp.477-487
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• 2004

Helical magneto-cumulative generators(MCGs) are devices which convert explosive energy into electromagnetic energy. The electromagnetic energy supplied from an external circuit is amplified by an explosively driven metal conductor mounted at the center of a helical coil compressing magnetic flux between the conductor and the coil. To optimize the coil design, output properties of small-size helical MCGs were measured while varying design parameters; the number of coil sections, length of the sections, pitch in the sections, and type of copper wire. Dimensions of the coil were kept constant, 50 mm in diameter and 200 mm in length. The coil was fabricated by using enamel-coated copper wire of 1 mm in diameter. The highest energy amplification ratio and figure of merit were 52.5 and 0.81, respectively. from an helical MCG with initial inductance of 63.7 $\mu$H at initial energy of 0.152 kJ Based on the experimental and calculated results, empirical formulas capable of optimizing coil designs were derived. By using these formulas, pitch in each coil section can be obtained at an arbitrary inductive load for high energy amplification ratio and figure of merit.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.43-46
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• 2007

Solenoid coil is one of the commonly used one in superconducting power machines because it can produce uniform magnetic field at the center of the coil. Most of the AC loss in a solenoid coil is magnetization loss which is generated by the perpendicular magnetic field. This paper compares the electrical characteristics of two solenoid coils made of YBCO wire and BSCCO wire. We made and tested the BSCCO solenoid coil and YBCO solenoid coil which had the same number of turns and inner diameter. Number of turns and inner diameter of both coils were 30 turns and 10cm, respectively. AC loss of both coils were calculated by using the finite element method. Result shows that AC loss of YBCO coil was about 1/7 of that of the BSCCO coil when the current was 40A.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1607-1615
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• 2007

We investigated the applicability of the TEM-l ${\beta}$-lactamase fragment complementation (BFC) system to develop a strategy for the screening of protein-protein interactions in bacteria. A BFC system containing a human Fas-associated death domain (hFADD) and human Fas death domain (hFasDD) was generated. The hFADD-hFasDD interaction was verified by cell survivability in ampicillin-containing medium and the colorimetric change of nitrocefin. It was also confirmed by His pull-down assay using cell lysates obtained in selection steps. A coiled-coil helix coiled-coil domain-containing protein 5 (CHCH5) was identified as an interacting protein of human uracil DNA glycosylase (hUNG) from the bacterial BFC cDNA library strategy. The interaction between hUNG and CHCH5 was further confirmed with immunoprecipitation using a mammalian expression system. CHCH5 enhanced the DNA glycosylase activity of hUNG to remove uracil from DNA duplexes containing a U/G mismatch pair. These results suggest that the bacterial BFC cDNA library strategy can be effectively used to identify interacting protein pairs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.33-37
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• 2003

Endovaginal and endorectal receiver only surface coil were designed for MR imaging(MRI) and $^1H$ MR spectroscopy(MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round comer. The shape of endorectal coil wire was long elliptic shape during insertion and circular shape after insertion. Conventional spin echo and fast spin echo sequences were used as T1 and T2 weighted imaging sequences, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method. Using home-built endvaginal and endorectal coils, excellent T1 and T2 images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo $^1H$ MRS was useful to differentiate the cancerous tissue from the normal tissue.