• 한국항행학회논문지
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• 제17권2호
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• pp.202-207
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• 2013

본 논문에서는 병렬 연결된 전송선로를 이용하여 고 비율 비대칭 전력 분배기를 설계하였다. 병렬 연결된 전송선로는 마이크로스트립 기술로 구현하기 어려운 낮은 임피던스의 전송선로를 높은 임피던스 전송선로로 구현하는 방법이다. 비율 비대칭 분배기 구현 시 사용되는 낮은 임피던스를 구현하기 위하여 병렬 연결된 전송선로를 이용함으로서 구현을 쉽게 할 수 있었다. 이러한 설계방법의 타당성을 보이기 위해서 중심 주파수 1 GHz에서 10:1 비율의 비대칭 전력 분배기를 제작하였고, 이것의 특성은 시뮬레이션과 거의 동일함을 확인하였다.

• 상하수도학회지
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• 제27권1호
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• pp.129-138
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• 2013

Water interruption is often caused by a rupture in the branch-like singular pipeline. This will cause critical complaints from household and may decrease public service quality. As an alternative of singular pipeline, additional parallel pipeline could be installed for sustainable water supply. This system is called double pipeline system and able to be utilized for water transmission line between treatment plant and distribution reservoir. Construction of double pipeline was thought to increase capital cost, which can be an issue to waterworks authorities. Reducing capital cost was possible by means of installing connectors between two parallel pipelines because of reduced diameter of each pipe. To obtain optimal design condition for connectors, it was necessary to compare water pressure according to accident location, to investigate flow according to connection pipe spacing, connection pipe diameter, and aging of pipe. Reliable and economical connection layouts were determined based on these results. The cost estimation for each design condition was carried out. Cost was approximately reduced by 20 ~ 30 % compared to the double pipeline without connections. In addition to this, connection between double pipelines could expect extra benefits for maintenance since the pipe could be repaired and rehabilitated without interruption.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.271-271
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• 2012

Many studies have been investigated on high density plasma source (Electron Cyclotron Resonance, Inductively Coupled Plasma, Helicon plasma) for large area source after It is announced that productivity of plasma process depends on plasma density. In this presentation, we will propose the new concept of the multiple source, which consists of a parallel connection of ICP sources and helicon plasma sources. For plasma uniformity, equivalent power (especially, equivalent current in ICP & Helicon) should distribute on each source. We design power feeding line as coaxial transmission line with same length of ground line in each source for equivalent power distribution. And we confirm the equivalent power distribution with simulation and experimental result. Based on basic study, we develop the plasma source for oxidation in semiconductor process. we will discuss the relationship between the processing parameters (With or WithOut magnet, operating pressure, input power ). In ICP, plasma density uniformity is uniform. In ICP with magnet (or Helicon) plasma density is not uniform. As a result, new design (magnet arrangement and gas distributor and etc..) are needed for uniform plasma density in ICP with magnet and Helicon.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.231-234
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• 2000

In this paper, we formed a transmitter and receiver by using three identical Chuas circuits and then formed wire and wireless transmission line from the channel which was between those three circuits. We proposed a secure communication method in which the desired information signal was synthesized with the chaos signal created in a Chuas circuit and sent to the transmitter through channel. Then the signal was demodulated receiver of Chuas circuit. The method we used to accomplish the secure communication was synthesizing the desired information with the chaos circuit by parallel connection in a wireless transmission line. After transmitting the synthesized signal to the wire and wireless transmission line, we confirmed the actuality of the secure communication by separating the information signal and the chaos signal in the receiver.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.263-266
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• 2000

In this paper, we formed a transmitter and receiver by using two identical Chua's circuits and then formed wireless transmission line from the channel which was between those two circuits. We proposed a secure communication method in which the desired information signal was synthesized with the chaos signal created in a Chua's circuit and sent to the transmitter through channel. Then the signal was demodulated receiver of Chua's circuit. The method we used to accomplish the sun communication was synthesizing the desired information with the chaos circuit by parallel connection in a wireless transmission line. After transmitting the synthesized signal to the wireless transmission line, we confirmed the actuality of the secure communication by separating the information signal and the chaos signal in the receiver. In order to confirm the security, we compared the wiretapped signal and the recovery signal under the assumption that the wiretapping had taken place. In order to separate the two signals, we transformed the information signal to a current source in the transmitter and detected the current in the receiver.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.238-241
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• 2000

In this paper, we formed a transmitter and receiver by using two identical Chua's circuits and then formed wireless transmission line from the channel which was between those two circuits. We proposed a secure communication method in which the desired information signal was synthesized with the chaos signal created in a Chua's circuit and sent to the transmitter through channel. Then the signal was demodulated receiver of Chua's circuit. The Method we used to accomplish the secure communication was synthesizing the desired information with the chaos circuit by parallel connection in a wireless transmission line. After transmitting the synthesized signal to the wireless transmission line, we confirmed the actuality of the secure communication by separating the information signal and the chads signal in the receiver. In order to confirm the security, we compared the wiretapped signal and the recovery signal under the assumption that the wiretapping had taken place. In order to separate the two signals, we transformed the information signal to a current source in the transmitter and detected the current in the receiver.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1919-1921
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• 2002

In this paper, we were designed the ferroelectric phase shifter using 3-dB, $90^{\circ}$ branch-line hybrid coupler with two ports terminated in symmetric phase-controllable reflective networks. The design of phase shifter is based on reflection theory of terminating circuits. In order to find the optimum conditions of reflect phase, the effect of a change of capacitance and transmission line connected with two coupled ports of a coupler have been investigated. To obtain more accurate design parameters, finite element method is applied. We were showed large phase variation with small capacitance variation in the parallel connection of capacitor and transmission line by using EM-simulation and circuit-simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.87-89
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• 2005

This paper proposes new series and parallel Sin+Cos PSS(power system stabilizer) for the purpose to improve the existing PSS1A's performance. The purpose of PSS is used to enhance damping of power system oscillations through injection of auxiliary signal for an excitation control terminal. The Proposed series and Parallel Sin+Cos PSS is connected adding the Sin+Cos terms additionally with serial and with parallel connection in a conventional PSS1A. The proposed controller is aim to considering of a damping of oscillation when it changes parameter fluctuations or operational load variations in a power system. The object of electric power system is KEPCO system and the voltage of power transmission line is a 154kV and a 345kV. The PSCAD/EMTDC package is used to authorize the effect of the proposed controller. Simulations were shown by and compared with the waveforms for frequency, voltage and electric power.

• 한국전자파학회논문지
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• 제19권10호
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• pp.1122-1128
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• 2008

본 연구에서는 Right-handed 전송 선로(RHTL)의 저역 통과 특성과 Left-handed 전송 선로(LHTL)의 고역 통과 특성을 결합한 구조의 가변 대역 저지 필터를 제안하였다. RHTL, LHTL의 분산 특성을 ABCD 행렬을 통해 구하고 차단 주파수를 계산하였다. 바렉터 다이오드와 칩 인덕터를 이용하여 RHTL,LHTL 단위 셀을 구성하고 각각 4개의 단위 셀이 연결된 RHTL, LHTL을 병렬로 연결하여 가변 대역 저지 특성을 구현하였다 제작된 가변 대역 저지 필터는 저역 차단 주파수 $280{\sim}395$ MHz, 고역 차단 주파수 $770{\sim}940$ MHz의 가변 특성을 갖는다.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.378-384
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• 2005

This paper proposes a new series and parallel Sin+Cos PSS (power system stabilizer) for the purpose of improving the existing PSS1A's performance. The purpose of the PSS is to enhance the damping of power system oscillations through injection of auxiliary signals for an excitation control terminal. The proposed series and parallel Sin+Cos PSS is connected adding the Sin+Cos terms additionally with the serial and parallel connection in a conventional PSS1A. The proposed controller is aimed at considering the damping of oscillation when it changes parameter fluctuations or operational load variations in a power system. The electric power system used is the KEPCO system and the voltage of the power transmission line is 154kV and 345kV. The PSCAD/EMTDC package is used to authorize the effect of the proposed controller. Simulations were shown by and compared with the waveforms for frequency, voltage and electric power.