• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.273-273
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• 2010

Recently, extensive research on hetero-junction arrays has been reported owing to its unique band gaps dissimilar to that of homo-junctions. These hetero-junction devices can be used in laser, solar cells, and various sensors. We report on the facile method to fabricate SWCNTs/SnO2 nanowires hetero-junction arrays on flexible polyimide substrate. Each SWCNT field effect transistor (FET) and SnO2 nanowire FET exhibits the purely p- and n-type charactersistics with ohmic contact properties. Such formed pn-junctions showed rectification behaviors reproducibly with a rectification ratio of ${\sim}3{\times}103$ at 1 V and ideality factors about 12. The pn-junctions also showed a good gate modulation behavior.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1915-1918
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• 2002

본 논문에서는 non-radiative dielectric (NRD) guide를 이용한 듀플렉서를 설계하였다. 설계된 듀플렉스는 두 개의 gap-coupled 필터와 T-junction으로 구성되어 있다. Gap-coupled 필터의 설계에는 차단 주파수 영역 등가회로를 이용하였으며 T-junction은 30dB 이상의 반사손실을 갖도록 최적화하여 두 가지의 형태로 설계하였다 위의 설계과정을 통하여 1% 대역폭, 0.1dB ripple, 37.7 및 38.3 GHz의 중심주 파수를 갖는 듀플렉서를 설계하였다. 두 가지 형태의 결합부를 갖는 듀플렉서에 대해 시뮬레이션하여 응답특성을 비교한 결과 듀플렉서의 응답특성이 원하는 결과에 근접하게 나옴을 확인하였다.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.163-171
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• 2002

Neuromuscular junction consist of presynaptic membrane, synaptic cleft and postsynaptic membrane. In the neuromuscular junction, presynaptic membrane is the motor nerve terminal, have many synaptic vesicle. Postsynaptic membrane is the motor end plate of muscle fiber and the most striking structural features are the deep infolding of the sarcolemma. Between the nerve and muscle cells, there is a synaptic cleft of some 50-100nm. This review shows the ultrastructure and function of neuromuscular junction, summarizes the current knowledge.

• The Journal of Korean Physical Therapy
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• v.19 no.3
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• pp.19-30
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• 2007

Purpose: This study was performed to investigate the effects of NMES for recovery of skeletal muscle. Methods: The normal group consisted of healthy rat without cast immobilization. The control group was breeding at standard cage during 7 days after 2 weeks-cast immobilization on hind limb. The experimental group. I. received NMES application during days after 2 weeks-cast immobilization on hind limb. The effects were measured with NT-3 immunoreactivity in neuromuscular junction by light microscope. Results: Immunoreactivity of NT-3 at the neuromuscular junction was higher appeared experimental groups than control group. Then, There was a little detection in the normal and control group. Conclusion: These therapeutic interventions enhance expression of NT-3 at the neuromuscular junction. Also, NMES is considered to effect on a normal structural formation and NT-3 expression at the neuromuscular junction.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.12
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• pp.1264-1268
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• 2003

In this paper, we have designed the duplexer using non-radiative dielectric(NRD) guide in millimeter wave band. The designed duplexer is composed of two stepped-impedance filters and T-junction. Stepped-impedance filters we designed with an equivalent circuit model of evanescent waveguide and the T-junction is optimized to minimize return loss of -20 dB or more. The characteristics of duplexer show good agreements with the expected results.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.37-45
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• 1998

In this paper, present status of super high-efficiency tandem solar cells has been reviewed and key issues for realizing super high-efficiency have also been discussed. In addition, the terretrial R&D activities of tandem cells, in the New Sunshine Program of MITI(Ministry of International Trade and Industry) and NEDO(New Energy and Industrial Technology Development Organization) in Japan are reviewed briefly. The mechanical stacked 3-junction cells of monolithically grown InGaP/GaAs 2-junction cells and InGaAs cells have reached the highest efficiency achieved in Japan of 33.3% at 1-sun AM1.5. This paper also reports high-efficiency InGaP/GaAs 2-junction solar cells with a world-record efficiency of 26.9% at AM0, 28$^{\circ}C$ and radiation damage recovery phenomena of the tandem cell performance due to minority-carrier injection under light illumination or forward bias, which causes defect annealing in InGaP top cells. Future prospects for realizing super-high efficiency and low-cost tandem solar cells are also described.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1435-1438
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• 1994

The effects of Ge composition variation in $a-Si_{1-x}Ge_x:H$ alloy p-i-n solar cells on the physical properties and current density-voltage characteristics are analyzed by a new simulation modelling based on the update published experimental datas. The simulation modelling includes newly formulated density of gap density spectrum corresponding to Ge composition variation and utilizes the newly derived generation rate formulars which include the reflection coefficients and can apply to multijunction structures as well as single junction structure. The effects in $a-Si_{1-x}Ge_x:H$ single junction are analyzed through the efficiency, fill factor, open circuit voltage, short circuit current density, free carriers, trap carriers, electric field, generation rate and recombination rate. Based on the results analyzed in single junction structure, the applications to multiple junction structures are discussed and the optimal conditions reaching to a high performance are investigated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.8
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• pp.587-590
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• 2013

Release competition and development of eco-friendly vehicles have been conducted violently also automaker, it will be a high growth industry of the charger and battery, which is the driving source of the motor of an electric vehicle. Reduces the on-resistance power elements DC - DC converter for battery charger for electric vehicles, must minimize switching losses. Should have a low on-resistance power than existing products. Compare the Super Junction MOSFET and Planar MOSFET, As a result, super junction MOSFET improve on about 87.4% on-state voltage drop performance than planar MOSFET.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.4
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• pp.210-213
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• 2017

In this paper, we analyzed the structural design and electrical characteristics of a 3.3 kV super junction FS IGBT as a next generation power device. The device parameters were extracted by design and process simulation. To obtain optimal breakdown voltage, we researched the breakdown characteristics. Initially, we confirmed that the breakdown voltage decreased as trench depth increased. We analyzed the breakdown voltage according to p pillar dose. As a result of the experiment, we confirmed that the breakdown voltage increased as p pillar dose increased. To obtain more than 3.3 kV, the p pillar dose was $5{\times}10^{13}cm^{-2}$, and the epi layer resistance was $140{\Omega}$. We extracted design and process parameters considering the on state voltage drop.

• ETRI Journal
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• v.37 no.5
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• pp.951-960
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• 2015

For a conventional power metal-oxide-semiconductor field-effect transistor (MOSFET), there is a trade-off between specific on-state resistance and breakdown voltage. To overcome this trade-off, a super-junction trench MOSFET (TMOSFET) structure is suggested; within this structure, the ability to sense the temperature distribution of the TMOSFET is very important since heat is generated in the junction area, thus affecting its reliability. Generally, there are two types of temperature-sensing structures-diode and resistive. In this paper, a diode-type temperature-sensing structure for a TMOSFET is designed for a brushless direct current motor with on-resistance of $96m{\Omega}{\cdot}mm^2$. The temperature distribution for an ultra-low on-resistance power MOSFET has been analyzed for various bonding schemes. The multi-bonding and stripe bonding cases show a maximum temperature that is lower than that for the single-bonding case. It is shown that the metal resistance at the source area is non-negligible and should therefore be considered depending on the application for current driving capability.