• 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 the Korean Society of Fisheries and Ocean Technology
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• v.36 no.1
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• pp.25-32
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• 2000

A combination steering system was designed to provide the flexibility in controlling the steering wheel in fishing operations of the inshore and coastal fishing vessels. The designed steering system basically is consisted of three driving units, such as a electrically driven hydraulic pump unit with a solenoid control valve, a DC motor driven hydraulic pump unit and a manually driven hydraulic pump unit, and two controllers to provide remote steering on the deck, respectively. The steering torque was measured and analyzed to investigate the dynamic performance of the developed steering system. The steering system showed excellent linearity between the working pressure of cylinder and the torque of rudder post in case of increasing in rudder angle from $5^{\circ} to 35^{\circ}$ that is, the steering torque increased from $10.4 kgf{\cdot}m$ to $105.3 kgf{\cdot}m$ and then the working pressure of cylinder fluctuated from 6.3 kgf/cm super(2) to 16.4 kgf/cm super(2). The steering time of 3.2 sec in remote hydraulic steering by the on/off solenoid valve control was much faster than 13.2 sec in the manual steering by the helmsman and 11.6 sec in the electric steering by a DC motor, and then it was verified that operation of one unit does not affect other units in combination steering system in any way. Furthermore, the developed steering system can be remotely controlled in multiple stations of the deck during the fishing operation and the automatic pilot steering unit can be used to add hydraulic steering.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.261-267
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• 2016

In this paper, Method for the phase distortion compensation timing offset and DC eliminator for the pilot component estimation and removal, transmitted and received signal correlation in the delay scheme DAB interference cancellation based on the same channel for using for estimating the feedback signal based on a between for removal for the timing offset compensation It proposes a repeater. This was applied to the ATSC system. The on-channel repeater of the proposed interference cancellation based on the interference removing capability is improved in interference signal is 20dB greater than the primary transmission signal environment via the return channel estimation and improve performance RFP. Accordingly, it was confirmed by simulation that good signal is sent out with the improvement of the ability of the repeater.

• ETRI Journal
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• v.33 no.5
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• pp.670-678
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• 2011

This paper investigates the design and performance of a digital on-channel repeater (DOCR) for use in Advanced Television Systems Committee (ATSC) digital television (DTV) broadcasting. The main drawback of a DOCR is the echo interference caused by coupling between transmitter and receiver antennas, which induces system instability and performance degradation. In order to overcome this problem, an echo canceller based on the adaptive echo channel estimation (ECE) technique has been researched and applied for a DOCR. However, in the case of ATSC, the pilot signal, which is used for carrier synchronization, may cause a DC offset error and reduce the isolation performance of the echo canceller for a DOCR in an ATSC network. Moreover, since the multipath fading effect of a radio channel usually occurs in a real environment, it should be minimized to improve the overall performance of a DOCR. Therefore, due to the limited isolation performance of echo canceller and the multipath fading effect, an interference cancellation system (ICS) is proposed for a DOCR in an ATSC network. The performance of the proposed DOCR with an ICS is evaluated by software simulation and hardware test results.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.594-600
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• 2017

HVDC transmission systems can be configured in many ways to take into account cost, flexibility and operational requirements. [1] For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required to charge and discharge the cable capacitance of each cycle. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may still be warranted, due to other benefits of direct current links. HVDC allows power transmission between unsynchronized AC transmission systems. Since the power flow through an HVDC link can be controlled independently of the phase angle between the source and the load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as 50 Hz and 60 Hz. This improves the stability and economy of each grid, by allowing the exchange of power between incompatible networks. This paper proposed to establish Korean HVDC technology through a cooperative agreement between KEPCO and LSIS in 2010. During the first stage (2012), a design of the ${\pm}80kV$ 60MW HVDC bipole system was created by both KEPCO and LSIS. The HVDC system was constructed and an operation test was completed in December 2012. During the second stage, the pole#2 system was fully replaced with components that LSIS had recently developed. LSIS also successfully completed the operation test. (2014.3)

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.11-18
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• 1998

A binary line code, called MB46d, is designed by use of the BUDA(Binary Unit DSV and ASV) cell concept to retain the property of being runlength limited, DC tree, and with a power spectral null at the Nyquist frequency. This new code is a stateless line code with a simple encoding and a decoding rule and enables efficient error monitoring. The power spectrum and the eye pattern of the new line code are simulated for a minimum-bandwidth digital transmission system where the sinc function is used as a basic pulse. The obtained power null at the Nyquist frequency is wide enough to enable easy band-limiting as well as secure insertion of a clock pilot where necessary. The eye is also substantially wide to tolerate a fair amount of timing jitter in the receiver.