• Bulletin of Korea Environmental Preservation Association
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• s.375
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• pp.2-3
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• 2008

• Proceedings of the KSMRM Conference
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• 1998.10a
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• pp.99-104
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• 1998

• Proceedings of the KSMRM Conference
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• 1997.03a
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• pp.37-40
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• 1997

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1247-1248
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• 1997

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1146-1148
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• 1995

To improve the breakdown characteristics of vertical power devices, field limiting ring(FLR) is popularly used. In this paper, at vertical power device having $300{\sim}600V$ breakdown voltage, FLR thecnique is considered, by two dimensional computer simulator, with the various of parameters; number of FLR, seperation distance of first FLR from the main juncton and second FLR from the first FLR, doping concentration and thickness of epi-layer, etc.. Below $40{\mu}m$ epi thickness, and for the case of one FLR, the maximum breakdown voltage, 580V is obtained.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.86-92
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• 2002

A short synthesis of novel prostanoids, 12-epi-carbacyclins 3 and 24, has been accomplished using palladium chemistry as a key step. The silyl enol ether 10a prepared through organopalladium chemistry has been allowed to react with 1-octen-3-one in the presence of $Pd(OAc)_2$ to give compound 12 in a single step. The unusual chemo- and stereoselective reduction of the ${\alpha},{\beta}$-unsaturated ketone in 12 has been effected with (S)-BINALH. Subsequent desilylation and Wittig reaction have provided the Subsequent desilylation and Wittig reaction have provided the $PGI_2$ analogues 3 and 24.

• 전기의세계
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• v.26 no.5
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• pp.83-89
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• 1977

This paper described the minority carrier lifetime in Si epitaxial layer, and also the voltage (V) versus current (I) characteristics of high resistivity Si epitaxial layer0substrate junction. The measured lifetime in Si epi-layer was much shorter than in bulk, and the temperature dependence of lifetime was found to agree well with Shockley-Read model of recombination which applies to high resistivity n-type materials. The V-I curve showed; an ohmic region (I.var.V), a sublinear region (I.var.V$^{1}$2/), a space charge limited current region (I.var.V$^{2}$), and finally a negative resistance region. We investigated these phenomena by the theory of the relaxation semiconductor.

• The Korean Journal of Pain
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• v.28 no.4
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• pp.287-289
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• 2015

Brachial plexus block (BPB) under ultrasound guidance has come to be widely used. However, nerve injury has been reported following ultrasound-guided BPB. We hypothesized that BPB under ultrasound guidance in conjunction with real-time electrical nerve stimulation would help us prevent nerve injury and do more successful procedure. Here, we report the successful induction and maintenance of ultrasound-guided BPB and the achievement of good peri- and postoperative pain control using a conductive catheter, the EpiStim$^{(R)}$.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.178-178
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• 2001

목적： 본 연구에서는 초당 $10^{9}$ 부동점 연산이 가능한 Texas Instrument사의 TMS320C6701 DSP를 이용하여 연속적으로 변하는 경사자계를 real-time으로 계산하여 후, 4 채널의 phase array 코일을 이용하여 영상을 얻은 후 빠른 재구성을 통하여 영상을 확인할 수 있는 spectrometer를 개발하였다. 대상 및 방법： 실시간 구현을 위하여 DSP 보드에 Texas Instruments(Tl)사의 TMS320C6701을 장착하였다. Transmitter, receiver, 그리고 gradient를 담당하는 DSP 보드들과 이들과 연결되어 rf modulation, gradient waveform을 만드는 analog board와 phased array coil을 위한 4 채널까지 측정이 가능한 receiver board로 구성하였다. Gradient 보드의 경우 각 경사자계의 채널(Gx, Gy, Gz)의 sampling points를 real-time으로 각각 계산함으로써 blipped-EPI 뿐만 아니라, 경사자계 파형이 연속적으로 변화하는 spiral-EPI의 실험도 가능하게 하였다.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.113-113
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• 2001

Purpose： In the gradient echo EPI the conventional T2＊-weighted image is poor in signal as well distorted by the field inhomogeneity. By acquiring a proton density image in addition to th T2＊-weighted image at the same scan, the fMRI processing can be improved. Method： The central region of the k space is acquired twice at different time points after th RF pulse while acquiring the other regions onc as described in Fig. 1. In Fig. 1 the segment numbers are chronological. Then, we can get two images of different contrast by interleaving th central region in the k space as done in the dua contrast FSE.