• 한국정보처리학회논문지
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• 제1권4호
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• pp.479-489
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• 1994

정보신호계열을 초고속으로 전송하기 위한 디지틀 광전송 시스템이 대용량화, 경 제화됨에 따라, 효율적으로 순수 정보신호계열을 신뢰성있게 전송할 수 있는 초고속 광전송 시스템용 전송로 부호의 선택이 현시점에서 중요한 문제로 대두되고 있다. 따라서 본 논문에서는 지금 까지 제안된 2치 unipolar 전송로 부호들 중 고속(100Mb/s 이상의 전송속도) 광전송 시스템으로 적합한 전송로 부호들을 우선 선택하여, 선택한 전송로 부호들 간의 성능 평가를 전송로 부호의 요구조건들, 즉 최대 동부호 연속수, 전송지연시간, 클럭 상승률, 마크율, 회로규모, 전송로 에러 감시 및 전력 스펙트럼에 따라 상호 비교 분석 한 결과, mBIZ부호가 최적의 초고속 광전송 시스템용 전송로 부 호임을 밝혔다.

• 소음진동
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• 제7권5호
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• pp.729-736
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• 1997

The subspan oscillation is the most important in bundled transmission lines, which can cause conductor damage and transmission line hardware failures. So it is necessary to analyze the subspan oscillation in details for transmission lines. This paper suggests the basic concept and theoretical analysis method of subspan oscillation for 6 bundle conductor transmission line, which considers wind speed, subspan length and conductor tension. Especially this paper uses a spacer damper model with clamp-arm flexibility and damping characteristics. Theoretical analysis results are proposed.

• Journal of electromagnetic engineering and science
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• 제4권2호
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• pp.68-71
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• 2004

The limitation of telegrapher's equations for analysis of nonuniform transmission lines is investigated here. It is shown theoretically that the input impedance of a nonuniform transmission line cannot be derived uniquely from the Riccati equation only except for the exponential transmission line of a particular frequency-dependent taper. As an example, the input impedance of an angled two-plate transmission line is calculated by solving the telegrapher's equations numerically. The numerical results suffer from larger deviation from its rigorous solution as the plate angle increases.

• 한국정보통신학회논문지
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• 제18권10호
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• pp.2339-2344
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• 2014

마이크로스트립 선로 형태의 전송선로 밑면에 플로팅 동판을 위치시키면 플로팅 동판과 접지면 사이의 단락 또는 개방 연결에 따라 전송선로는 마이크로스트립 선로 또는 코플라나 선로 형태로 동작하게 된다. 이러한 동작은 하나의 전송 선로 폭에 대해 서로 다른 두 개의 특성 임피던스를 가질 수 있음을 의미한다. 플로팅 동판이 존재하는 마이크로스트립 전송 선로를 이용하여 안정적인 입력 정합 상태를 가지며 조건에 따라 단순히 신호를 전달하는 2-단자 전력 전송 선로 또는 전력 분배가 가능한 2-way 전력 분배 회로로 동작할 수 있는 가변 전송선로를 제안 및 제작하였다. 제안된 회로는 코플라나 선로로 동작하는 경우에는 전력 전송 선로로 동작하고, 마이크로스트립 선로로 동작하는 경우에는 2-way 전력 분배 회로로 동작한다. 제작된 가변 전송 선로는 700 MHz 이상의 주파수에서 전력 전송 선로로 동작하는 경우 -0.2 dB 이내의 전달 손실($S_{21}$)과 -15 dB 이하의 반사 계수($S_{11}$)를 보였으며, 전력 분배 선로로 동작하는 경우에는 -10 dB 이하의 반사 계수($S_{11}$), -3.8 dB이내의 전달 손실($S_{21}$ or $S_{31}$), ${\pm}0.3dB$이내의 출력 전력차($S_{21}/S_{31}$)를 보였다.

• 한국전자파학회논문지
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• 제15권11호
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• pp.1069-1074
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• 2004

본 논문에서는 직렬 inter-digital 커패시터와 이중 병렬 인덕티브 쇼트 스텁으로 구성된 double negative(DNG) 전송 선로를 설계하였다. 이러한 DNG 전송 선로는 특정한 주파수 이상에서는 double positive(DPS) 전송 선로의 특성을 가진다. 다시 말해서, 설계된 전송 선로는 DNG와DPS전송 선로의 특성을 주파수에 따라서 동시에 가진다. 누설파 대역에서의 DPS/DNG 전송 선로는 주파수 스캐닝 안테나로 이용되어 질 수 있다. 대칭 누설파 안테나의 분산 특성과 원거리 방사 패턴을 모의실험하였고 제작 및 측정하였다. 모의실험 결과는 측정결과와 대략 일치하였다.

• 전기학회논문지
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• 제59권9호
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• pp.1638-1643
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• 2010

HVDC is better economic method than HVAC in case of long distance transmission and it is possible to interconnect transmission lines regardless of difference of power frequency. The electrical environment problems of HVDC overhead transmission line are electric field, charged voltage, ion current and so on. For biopolar HVDC lines, most of the ions are directed toward the opposite polarity conductor, but a significant fraction is also directed toward the ground. These problems are major factor to design configuration of HVDC overhead transmission line. Therefore, It is necessary to test an environmental characteristics of HVDC overhead transmission line. In this paper, to assess the ion characteristic of HVDC transmission line, continuous measurements have been done on the biopolar single circuit line with ACSR 480mm2-6 bundle conductors of Gochang HVDC Test line. And then the ion characteristics were analyzed.

• 대한기계학회논문집A
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• 제27권4호
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• pp.567-576
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• 2003

In this study, a robust controller to control pressure in a pneumatic pressure vessel with a long transmission line is proposed. Frequency response of transmission line using compressible fluid is changed by the flowing state of the fluid. So, it a fixed gain controller designed based on a model supposed the flowing state to a specific state, the performance of the control system could be degraded because of the modelling error. The controller designed in this study is composed of two parts. One is a feedback controller to improve a feedback characteristics and to compensate the influence of the variation of transfer characteristics of a transmission line owing to the change of flowing state and the other is a feedforward controller to regulate command fallowing performance. The experimental results with the designed controller show that the robustness of the control system is achieved regardless of the change of the model or the transmission line. Therefore, the designed controller can be utilized for the Performance improvement of a Pressure control system with a long transmission line using compressible fluid.

• Smart Structures and Systems
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• 제34권1호
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• pp.1-8
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• 2024

Structural health monitoring (SHM) of concrete structures is necessary because structural safety is directly linked to life safety. This study proposes a transmission line configuration for SHM based on time domain reflectometry (TDR). For this purpose, six transmission lines consisting of electrical wires, rebars, and joints were prepared. The TDR waveforms were measured and analyzed in air and concrete using six transmission lines to select the most suitable configuration. A two-line wire with joints was selected as the optimal transmission line for SHM because it exhibited the highest sensitivity among the configurations. Experiments to apply SHM were performed on defective concrete blocks containing an optimal transmission line. The results showed that the defect locations in concrete were precisely investigated using TDR waveform analysis. The distances estimated from the TDR waveform were similar to the measured distances for the locations of the defects and joints in the concrete blocks. This study suggests that a transmission line consisting of two-line wires and joints may be an effective non-destructive evaluation tool for assessing the structural health of concrete.

• Earthquakes and Structures
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• 제16권5호
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• pp.513-522
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• 2019

A long-span transmission tower-line system is indispensable for long-distance electricity transmission across a large river or valley; hence, the failure of this system, especially the collapse of the supporting towers, has serious impacts on power grids. To ensure the safety and reliability of transmission systems, this study experimentally and numerically investigates the collapse failure of a 220 kV long-span transmission tower-line system subjected to severe earthquakes. A 1:20 scale model of a transmission tower-line system is constructed in this research, and shaking table tests are carried out. Furthermore, numerical studies are conducted in ABAQUS by using the Tian-Ma-Qu material model, the results of which are compared with the experimental findings. Good agreement is found between the experimental and numerical results, showing that the numerical simulation based on the Tian-Ma-Qu material model is able to predict the weak points and collapse process of the long-span transmission tower-line system. The failure of diagonal members at weak points constitutes the collapse-inducing factor, and the ultimate capacity and weakest segment vary with different seismic wave excitations. This research can further enrich the database for the seismic performance of long-span transmission tower-line systems.

• 대한전기학회논문지:전력기술부문A
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• 제53권6호
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• pp.350-357
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• 2004

In a deregulated electricity generation market, the sufficient capacity of transmission lines will promote the competition among generation companies (Gencos). In this paper, we show that Gencos' possession of rights to collect congestion rents may increase the competition effects of the transmission lines. In order for concrete analysis on this effect, a simple symmetric market model is introduced. In this framework, introducing the transmission right to the Gencos has the same strategic effects as increasing the line capacity of the transmission line. Moreover, the amount of effectively increased line capacity is equal to the amount of the line rights. We also show that the asymmetric share of the financial transmission rights may result in an asymmetric equilibrium even for symmetric firms and markets. We also demonstrate these aspects in equal line rights model and single firm line rights model. Finally, a numerical example is provided to show the basic idea of the proposed paper.