• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1863-1865
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• 2004

As rise the demands for the protcetion of environment and the compactness of equipments, the movement brisks for replacing the circuit breaker of GIS(Gas Insulated Switchgear) to VI(Vacuum Interrupter). For these reason an increase in the interruption capability of VI is required. To satisfy these requirement, the academic and industrial worlds have been studying extensively for AMF(Axial Magnetic Field) contact, which is effective in interrupting large current over tens of kA, and introduced many kind of AMF contacts. However there are little effort to compare these contacts comprehensively, so it is difficult to choose most suitable shape for user's needs. In this paper, focusing unipolar type contact among various type of AMF contacts, we performed magnetic field analysis for several models designed in same dimension and compared the result and characteristics of each model in order to help deciding the direction for developing profitable VIs for interrupting large current.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.196-199
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• 1998

LDM(Linear DC Motor) are used in high speed, high-precision position control system. Because of these advatages, LDM has already used in the motor of pen-recorder, magnetic-disk devices. Under the limited dimension, we propose the design method of LDM by magnetic circuit. In this paper, a relation between the thrust constant and size of a LDM that is moving coil type with unipolar is described, which is defined as a simple relational equation. To maximize the rate of thrust to the volume of LDM, the magnetic flux density in the yoke is adjusted to the value of magnetic equation. By the magnetic field analysis(FEM), the validity of the equation is confirmed.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.289-296
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• 2009

In this study, I presented power control unit with potential use in the magnetic stimulation of biological systems. The effect of the magnetic stimulation depends on the geometry and orientation of the induced electric field as well as on the current pulse waveform delivered by the stimulator coil. TMS is achieved from the outside of the head using pulses of electromagnetic field that induce an electric field in the brain. There are numerous possibities in the applications TMS, such as diagnosis and therapy through the brain stimulation. These factors are very important to define the equipment requirements and characteristics in that the topology of the power supply and the size and geometry of the coil. The proposed solution is the generation of current pulses with variable amplitude and duration, according to a user defined input. Another solution is the topology that uses elements to store and transfer energy from the power source to the load. In addition to proposed topology, an adequate control strategy and right set of the power circuit parameters made possible to obtain unipolar waves and bipolar waves.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.213-213
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• 1999

현재 LCD용 기판재료는 ITO/glass를 전극으로 사용하고 있다. 그러나 유리기판은 무겁고 깨지기 쉽기 때문에 사용상 곤란한 점이 많다. 최근 flexible하고 가공성 및 생산성이 우수한 플라스틱한 ITO를 성막하여 EL용, Touch panel, plastic LCD용 사용하려는 시도로, roll-to-roll 연속 스퍼터링에 의한 ITO성막공정에 대한 연구가 최근 활발하게 이루어지고 있다. 폴리머는 유리에 비해 Tg 온도가 낮고, 기판으로부터의 수분 및 여러 종류의 가스방출이 심하기 때문에 유리와는 달리 ITO막의 제조에 있어 큰 차이점이 있다. 따라서, 폴리머에 반응성 스퍼터링을 하기 위해서는 표면처리가 중요한 변수가 되며, roll to roll sputter로 ITO 필름을 얻기 위해서는 폭과 길이 방향으로 균일한 막을 얻는 것이 중요하다. 두께 75$\mu\textrm{m}$, 폭 190mm, 길이 400m로 권취된 광학용 Polyethylene terephthalate(PET:Tg:8$0^{\circ}C$)위에 In-10%Sn의 합금타겟과 Unipolar pulsed DC power supply를 사용하여 반응성 마그네트론 스퍼터링 방법으로 0.2m/min의 속도로 연속 스퍼터링 하였다. PET를 Ar/O2 혼합가스로 플라즈마 전처리를 한 후, AFM, XPS를 이용하여 효과를 분석을 하였고, 성막전에 가스방출을 막기 위해 TiO를 코팅하였다. Pilot 연속 생산공정에서 재현성을 위해 PEM(Plasma Emission Monitor)의 optical emission spectroscopy를 이용, 금속과 산화물의 천이구역에서 sprtter된 I/Sn 이온과 산소 이온의 반응에 의한 최적의 플라즈마의 강도값을 입력하여 플라즈마의 radiation을 검출하고, 스퍼터링 공정중 실질적인 in-situ 정보로 이용하였다. PEM을 통하여 In/Sn의 플라즈마 강도변화를 조사하였다. 초기 In/Sn의 플라즈마 강도(intensity)는 강도를 100하여, 산소를 주입한 결과, plasma intensity가 35 줄어들었고, 이때 우수한 ITO 박막을 얻을 수 있었다. Pulsed DC power를 사용하여 아크 현상을 방지하였다. PET 상에 coating 된 ITO 박막의 표면저항과 광투과도는 4-point prove와 spectrophotometer를 이용하여 분석하였고, AES로 박막의 두께에 따른 성분비를 확인하였다. ITO 박막의 광투과도는 산소의 유량과 sputter 된 In/Sn ion의 plasma emission peak에 따라 72%-92%까지 변화하였으며, 저항은 37$\Omega$/$\square$ 이상을 나타내었다. 박막의 Sn/In atomic ratio는 0.12, O/In의 비율은 In2O3의 화학양론적 비율인 1.5보다 작은 1.3을 나타내었다.

• Journal of Veterinary Clinics
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• v.14 no.2
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• pp.319-337
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• 1997

The electrocardiographic (ECG) parameters in the normal Korean black goat have been measured with a 3-channel Electrocardiograph and computed, analyzed. ECG in 243 black goats were made with the limb leads (I, II, III, aVR, aVL, aVF), that were recorded conduction parameters of wave and interval, and were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate were recorded by the ECG which were a mean of 106.1$\pm $21.8 beats/min. Average conduction times in the PR, the QRS complex and the QTc interval were recorded 103.9$\pm $34.9 msec., 58.3$\pm $23.2 msec. and 302.6$\pm $67.8 msec., in the P and T wave duration recorded 24.8$\pm $6.4 msec. and 51.7$\pm $10.8 msec. respectively. The shape of wave in each leads were observed various types, and any spacial wave type appeared the highest frequency in each lead that ware shown less than 60%, and these frequent rate and average amplitudes as fallow: 1. In P waver the frequent rate and average amplitudes of the positive type showed in leads I, II and aVL that were 54.8% (93.0$\pm $ 33.2 $\mu $V), 50.5% (90.1$\pm $30.5 $\mu $V) and 41.7% (58.5$\pm $ 31.1 $\mu $V). Average amplitude of the negative type showed the frequent rate of 49.8% in lead aVE which was -77.6$\pm$ 25.2 $\mu $V. Biphasic type in leads III and aVF were 46.1% (108.4 $\mu $V, -90.2 $\mu $V.) and 45.7% (137.4 $\mu $V, -105.4 $\mu $V.), and amplitudes between positive and negative of it were significant difference. 2. The highest amplitudes of the QRS complex in all leads were 534.8$\pm $ 232.3 $\mu $V of lead II. The frequent rate and amplitudes of the R wave type in the I, II, III and aVF were 30.2% (277.8 $\pm $131.3 $\mu $V), 45.1% (393.1$\pm $114.2 $\mu $V), 48.5% (349.3$\pm $178.3 $\mu $V) and 54.9% (334.4$\pm $129.7 $\mu $V), and QS ways type in the lead aVL was 49.5% (359.2$\pm $195.5$\mu $V), and RS and QS wave types in the lead a VR were 43.3% (312.4 $\mu $V, -212.7 $\mu $V.) and 41.1% (399.2$\pm $92.2 $\mu $V), respectively. 3. In T wave, the frequent rata and amplitudes of the positive type in the leads I, II, III and aVF were 44.6% (207.9$\pm $ 97.1 $\mu $V), 41.6% (245.1$\pm $92.1 $\mu $V), 46.9% (189.8$\pm $ 82.7 $\mu $V) and 53.0% (195.4197.8 $\mu $V), and the negative in the lead aVR was 41.2% (-230.7$\pm$ 103.1 $\mu $V), respectively. The positive and negative types in the lead aVe appeared with same frequent rate of 43.2%.4. Frontal plane vectors for P, QRS, and T were found to lie at 38.1$\pm $ 21.5, 142.0$\pm $ 57.2, and 117.2$\pm $ 63.9 degrees, respectively. These results in ECG of goats may be served to the limited purposes as to conduction parameters, arrhythmias except abnormal ECG because of waveforms, amplitudes and electrical axis of it were variability.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.132-138
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• 2002

Non-human primates are widely used for experimental animal and raised as companion animal in Korea. To establish the electrocadiogram (ECG) of non-human primates that are domestically raised, the author measured bipolar limb leads and augmented unipolar limb leads, after tiletamine/zolazepam (TZ) injection as sedative agents. The amplitudes of P,Q, R,S and T wave and duration time of P wave, QRS complex, PR and QT interval in each lead of ECG were evaluated in 7 non-human primates at 15 minutes after TZ injection, respectively. The amplitude of P wave in I, II,III, aVR, aVL and aVF leads revealed 0.06$\pm$ 0.05,0.14$\pm$ 0.05, 0.1 $\pm$ 0.05,-0.11 $\pm$ 0.06,-0.04$\pm$ 0.04 and 0.12$\pm$ 0.05 mV respectively. The amplitude of Q wave revealed -0.16$\pm$ 0.15, -0.23$\pm$ 0.18, -0.17$\pm$ 0.13, 0.16$\pm$0.13, 0.04$\pm$ 0.09 and -0.2$\pm$0.13 mV, respectively. The amplitude of R wave revealed 0.56$\pm$0.56, 1.24$\pm$ 0.67, 0.92$\pm$0.33, -0.37$\pm$ 1.14, -0.22$\pm$ 0.47 and 1.12 $\pm$ 0.47 mV, respectively. The amplitude of S wave revealed -0.02$\pm$ 0.08, -0.04$\pm$0.06, -0.06$\pm$0.04, 0.02$\pm$0.04, 0.04$\pm$0.09 and -0.04 $\pm$ 0.06 mV, respectively. The amplitude of T wave revealed -0.01 $\pm$ 0.15,-0.02$\pm$ 0.13, 0.01 $\pm$ 0.08, 0.02$\pm$ 0.12, 0.01 $\pm$ 0.11 and -0.03$\pm$ 0.09 mV, respectively. The duration time of P wave revealed 0.05 $\pm$ 0.01, 0.04$\pm$ 0.01, 0.05$\pm$ 0.02, 0.05 $\pm$ 0.02, 0.04$\pm$ 0.01 and 0.04$\pm$ 0.01 sec, respectively. The duration time of QRS complex revealed 0.05 $\pm$ 0.02,0.05$\pm$ 0.01, 0.05 $\pm$ 0.01, 0.04$\pm$ 0.01, 0.05$\pm$ 0.01 and 0.05 $\pm$ 0.01 sec, respectively. The duration time of PR interval revealed 0.08$\pm$ 0.01, 0.07$\pm$0.01,0.08$\pm$ 0.03, 0.08$\pm$0.01, 0.08$\pm$ 0.01 and 0.08$\pm$0.01 sec, respectively. The duration time of QT interval revealed 0.23$\pm$ 0.06, 0.22$\pm$ 0.05, 0.23 $\pm$ 0.06, 0.23$\pm$ 0.06, 0.24$\pm$ 0.05 and 0.22$\pm$ 0.02 sec, respectively. No significant changes were observed in e amplitude of P and T waves. The amplitude of QRS complex in ketamine group was higher than that of TZ group. However, no significant changes were observed in both intra-group and inter-group. There were no significant changes in the duration time of P wave, QRS complex and PR interval obtained from both groups. Also, the duration time of QT interval in TZ group was significantly longer at 30 min.(P< 0.05) an that of 10 minutes after injection. However, significant difference was not found between two groups. The mean cardiac electric axis in ketamine group tended to decrease until 30 min. after injection and then gradually increase. However, mean cardiac electric axis of TZ group was increased until 30 min. after injection and then decreased. But significant differences were not observed between groups. These results suggest that the ECG pattern after TZ injection to non-human primates reared in korea was established. It was also considered that the injection of ketamine and TZ didn't significantly affect on ECG pattern of the non-human primates.