• 제목/요약/키워드: Combined Transmission Line

검색결과 96건 처리시간 0.021초

개인용 컴퓨터를 이용한 전자 태아심음 감시장치의 개발에 관한 연구 (A Study on The Davelopement of Electronic Fetal Heart Rate Monitoring System Using Personal Computer)

  • 정지환;김선일
    • 대한의용생체공학회:의공학회지
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    • 제12권3호
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    • pp.209-214
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    • 1991
  • Digital fetal monitoring system based on the personal computer combined with the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultra- sound fetal Doppler signal for digital signal conditioning, rectification, low -pass filtering, autocorrealtion function calculation and its peak detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data transmission and on -line analysis of fetal heart rate change including on - line warning system, base -line estmation, acceleration, deceleration and variability. It is one of the most suitable situation to apply the DSP chip for siganl conditioning, digital filtering of ultrasound fetal Dopier signal and fetal heart rate estimation using autocorrelation technique .

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150m 철탑의 설계 I (A Design of 150 meters high steal tower)

  • 이재숙
    • 전기의세계
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    • 제17권3호
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    • pp.43-56
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    • 1968
  • The design of this antenna tower on the publication had been prepared by writer in order to compare with that of towers for power transmission line or to show the differences on designs existing on their design standards. The design of this antenna tower is also featuring on the following points; (1) the height of tower is 150meters high, (2) combined steel angles are adopted besides angles, (3) the direction of 45degree wind is taken account into design, (4) the additional stresses of horizontal members located in the bending points of main posts are contemplated though these additional stressess are not shown on stress diagram.

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전력선 통신 채널 Data Base 구축을 위한 기본 연구 (A Fundamental Study for Establishment of Channel Data Base in Power-Line Communications)

  • 오휘명;김관호;이원태;이재조
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권2호
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    • pp.107-111
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    • 2003
  • In the power-line communication systems, there are many factors of noise and attenuation in the power-line channels, because they were designed for not the communication but the power transmission. Also the transfer function of the channels is highly changed with the topology and the load of the power-lines. To cope with these poor channel situation, channel modeling, one of the many studies in progress, is being studied hard. Channel modeling is essential to apply the active schemes to overcome the bad channel(e.g. modulation technique, channel coding, signal coupling & filtering, etc.) to the power-line communications. In this paper, we have realized the statistical model(this model is suggested as the channel modeling method for the power-line channels) that is combined the transfer function with the various noises. And we have compared and examined the results with the measured data. Also we have studied the plan which can effectively establish the channel data base for the channel information consisted of the parameters that are derived from this modeling, and we have studied the plan to utilize the data base.

넓은 대역폭을 가지는 소형 링 하이브리드 (Ring Hybrid Coupler with Compact Size and Wide Bandwidth)

  • 김의중;김승환;김일규;이영순;김영;윤영철
    • 한국항행학회논문지
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    • 제13권2호
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    • pp.194-200
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    • 2009
  • 본 논문은 병렬 캐패시터와 고 임피던스 선로 그리고 CRLH-TLs (Composite Right/Left-Handed Transmission Lines)을 이용한 소형화와 대역폭 확장을 한 링 하이브리드 커플러 설계에 대한 것이다. 소형화를 위해 전송 선로의 길이를 줄이는 방법은 전송선로를 고 임피던스 선로와 병렬 캐패시터로 대체하였고, 또한 대역폭 향상을 위해서는 직렬 캐패시터와 병렬 인덕터로 구성된 CRLH 매타 재질의 비선형적인 위상특성을 이용하였다. 이렇게 제작된 링 하이브리드 커플러는 기존 커플러와 비교해서 크기는 10% 이하로 줄였으며, 대역폭은 60% 이상 확장되었음을 제시하였다.

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광대역 임피이던스정합용 불균일군차선로의 최적설계 (Optimal Design of Nonuniform Transmission Lime Sections for Wide-Band Impedance Matching)

  • 박송배
    • 대한전자공학회논문지
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    • 제11권6호
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    • pp.38-43
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    • 1974
  • 임의의 전원임피이던스와 임의의 부하임피이던스 사이에 삽입할 때 입력반사계수가 가급적 넓은 주파수범위에서 최소가 되는 임피이던스 정합용 불균일선로 섹션을 설계하는 문제를 고찰하였다. 고려대상의 불균일선로는 수학적으로는 특수한 종류에 속하는 것이나 실제적으로는 완만하게 변하는 거의 모든 전송선로를 포괄할 수 있다. 입력반사 계수의 계산에서는 선로의 ABCD 파라미터의 테일러 급수전관식을 이용하였다. 그리고 설계문제를 비선형 구속조건을 가진 비선형 프로그래밍 문제로서 수식화하였으며 이것을 수차적비구속 최소법(Sequential Unconstrained Minimigation Technique)과 Fletcher-Powell 방법을 병용하여 풀었다. 결과적으로 이제까지 광대역 임피이던시 정합편 전송선제로서 발표된 가장 우수한 것보다 훨씬 특성이 개선된 것을 얻을 수 있었다.

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실증시험을 통한 강관주기초의 거동특성 (Behavior of Single Pole Foundation using Experimental Study)

  • 김대홍;오기대
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.598-604
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    • 2010
  • The drilled pier foundation is widely used to support transmission line structures due to its simplicity of construction. When this foundation type is used in conjunction with a single shaft or H-frame structure, it is subjected to a high overturning moment, combined with modest vertical and shear loads. Since the length and diameter of drilled piers are often governed by a maximum permissible deflection, many drilled piers being installed today are very conservatively designed. In this study, Nine prototype field-tests (1/8 scale) have been conducted in order to determine the vertical and lateral resistance of drilled pier foundation for single pole structures. These test results reveal the test piers behaved essentially as rigid bodies in soil (6D) and the center of rotation of the pier were typically 0.6~0.4 of the pier depth below ground surface. Test results also show the relationship between the applied load and the deflection at the top of the pier is highly nonlinear.

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강관주 철탑기초의 수평거동에 관한 실험적 연구 (Experimental Study on the Laterally Loaded Behavior of Single Pole Foundation)

  • 김대홍;김경열
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.1087-1094
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    • 2008
  • The drilled pier foundation is widely used to support transmission line structures due to its simplicity of construction. When this foundation type is used in conjunction with a single shaft or H-frame structure, it is subjected to a high overturning moment, combined with modest vertical and shear loads. Since the length and diameter of drilled piers are often governed by a maximum permissible deflection, many drilled piers being installed today are very conservatively designed. In this study, Five prototype field-tests (1/8 scale) have been conducted in order to determine the lateral resistance of drilled pier foundation for single pole structures. These test results reveal the test piers behaved essentially as rigid bodies in soil (6D) and the center of rotation of the pier were typically 0.6~0.4 of the pier depth below ground surface. Test results also show the relationship between the applied load and the deflection at the top of the pier is highly nonlinear.

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대정전 계통 복구를 위한 시송전 선로에 관한 연구 (A Study on transmission lines energized initially to restore wide black out Power system)

  • 이흥재;김균도;박성민;배주천;황봉환;홍순천;김기동;이남호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 A
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    • pp.377-379
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    • 2001
  • When a wide area blackout occurres, reenergizing transmission lines should be done at first. The KEPCO(Korea Electric Power Corporation) divides whole power system grid into seven subsystem, and each subsystem has one of two blackstart power plants which are usually hydro or combined-combustion type, one priority power plant which should be first supplied with electric energy, and transmission lines between them. Voltage rising, line charging, and operation stability problem should be considered when these lines are reenergized. In this paper, building-up process for primary transmission system that should be energized at first is analyzed.

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Topology-Aware Fanout Set Division Scheme for QoS-Guaranteed Multicast Transmission

  • Kim, Kyungmin;Lee, Jaiyong
    • Journal of Communications and Networks
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    • 제15권6호
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    • pp.614-634
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    • 2013
  • The proliferation of real-time multimedia services requires huge amounts of data transactions demanding strict quality-of-service (QoS) guarantees. Multicast transmission is a promising technique because of its efficient network resource utilization. However, high head-of-line (HOL) blocking probability and lack of service-specific QoS control should be addressed for practical implementations of multicast networks. In this paper, a topology aware fanout set division (TAFD) scheme is proposed to resolve these problems. The proposed scheme is composed of two techniques that reduce HOL blocking probability and expedite packet delivery for large-delay branches regarding multicast tree topology. Since management of global topology information is not necessary, scalability of the proposed scheme is guaranteed. Mathematical analysis investigates effects of the proposed scheme and derives optimal operational parameters. The evaluation results show that the TAFD scheme achieves significant delay reduction and satisfies required delay bounds on various multicast networks.

Wideband Slow Light in a Line-defect Annular Photonic-crystal Waveguide

  • Kuang, Feng;Li, Feng;Yang, Zhihong;Wu, Hong
    • Current Optics and Photonics
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    • 제3권5호
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    • pp.438-444
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    • 2019
  • In this theoretical study, a line-defect photonic-crystal waveguide hosted in an annular photonic crystal was demonstrated to provide high-performance slow light with a wide band, low group-velocity dispersion, and a large normalized delay-bandwidth product. Combined with structural-parameter optimization and selective optofluid injection, the normalized delay-bandwidth product could be enhanced to a large value of 0.502 with a wide bandwidth of 58.4 nm in the optical-communication window, for a silicon-on-insulator structure. In addition, the group-velocity dispersion is on the order of $10^5$ ($ps^2/km$) in the slow-light region, which could be neglected while keeping the signal transmission unchanged.