• Title/Summary/Keyword: 고속철

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Optimization of panel parameters and drive signals for high-speed matrix addressing of a bistable twisted-nematic LCD (쌍안정 TN LCD의 고속 매트릭스 어드레싱을 위한 패널 파라미터와 구동 파형의 최적화)

  • 이기동;박구현;장기철;윤태훈;김재창;이응상
    • Korean Journal of Optics and Photonics
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    • v.9 no.6
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    • pp.417-422
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    • 1998
  • In this paper we introduce a method to optimize panel parameters and drive signals in a matrix-adressed bistable twsited-nematic (BTN) liquid crystal display (LCD) panel. We measured the effect of data pulses on optical switching characteristics in a BTN LC cell to model the effect theoretically. We introduce a weighting function to model the effect of data pulses on the switching energy as a function of time. Once the weighting function is known, we can estimate the maximum number of lines for multiplexing operation at a given frame rate by calculating the minimum data pulse width. By characterizing a unit cell as we change panel parameters (for example, d/p ratio), we can optimize parameters for high-speed operation. We found that our theoretical predictions agree very well with experimental results.

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Study of Tribological Characteristics Between Metallic friction materials and Brake Disk (금속계 마찰재와 제동디스크 간의 마찰특성 연구)

  • Kim, Sang-Ho;Park, Hyung-Chul;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2080-2093
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    • 2008
  • Disk brake system take charge of maximum braking energy among the mechanical brake systems for high speed train. For this reason, Metallic friction materials and heat resistant steel disk is adopted at disk brake system for high speed train. It was investigated tribological characteristics(friction coefficient, friction stability, wear rate and braking temperature) between some kinds of metallic friction materials and heat resistant steel disk. Cu-based friction material for high speed train have suitable tribological characteristics.

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The Design Guideline of the Buses as the Transportation Means to the KTX of Small/Medium Cities (중소도시 KTX와 연계교통수단으로서의 버스 디자인 가이드라인)

  • Choi, Chul-Joo
    • Journal of the Korean Society for Railway
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    • v.14 no.5
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    • pp.461-469
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    • 2011
  • Considering the traffic condition of railroad 'KTX' links to lack of service's punctuality in nation's small/ medium cities, design guidelines with practical railroad transportation policies in terms of convenient railroadbus connection and improving comfortable ride is suggested. Following the guideline and policies, operational requirements of current railroad-bus connection system, the system's design consideration, and transportation policies and laws in relation to the bus operating companies should be analyzed to decide the practicality of the railroad-bus connecting infrastructure. Also, in order to achieve practical railroad-bus connection, connecting buses' design guideline is combined with suggested optimization method of the practicality transportation system. Lastly, the design guideline of buses as 'links,' and railroad transportation policies concerning the operation of connecting bus system for nation's small/medium cities are suggested.

Effects of Group Delay and Non-linear Characteristics in Ka-Band High Data Rate Satellite Communication System (Ka 대역 초고속 위성통신 시스템에 대한 군지연 및 비선형 특성의 영향)

  • 김영완;박동철
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.4
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    • pp.600-610
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    • 2001
  • The effects of group delay and non-linear characteristics on high data rate(HDR) satellite channel are presented in this paper Based on the modeling of group delay and non-linear characteristics the system performances which provide various data rate services were analyzed in Ka-band satellite channel. As the transmission data rate is increased, the degradation due to these channel characteristics is severely increased. The linear component of group delay and the AM-AM component of non-linear characteristics severely affect the system performance. To efficiently provide the various service via the same transmission system it is necessary to equalize the primary impairment factors. The optimum operating points of HDR satellite transmission system are implemented by considering the analyzed results on channel characteristics.

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High-Speed Power Line Communication System using CCK Modulation (CCK 변조기법을 이용한 고속 PLC 시스템에 관한 연구)

  • Park, G.H.;Choi, Y.G.;Lee, B.K.;Kim, H.M.;Cha, J.S.;Shin, M.C.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.274-276
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    • 2003
  • 전력선 통신은 새로운 통신전용 선로나 별도의 추가 시설 없이, 기존의 전력 공급용 전력선로를 통신선로로 병용할 수 있다는 장점을 갖고 있다. 하지만 이러한 전력선 통신은 다양한 부하의 운전과 빈번한 부하의 기동 정지로 인하여 잡음이 발생하며 이에 본 연구에서는 전력선 채널의 협대역 잡음에 대처하는 변조방식을 제시함과 동시에 최근 들어 고용량 데이터 전송이 빈번한 홈 네트워크분야에 응용될 수 있는 고속 전력선 통신 기법을 제안하고자 한다. 본 논문에서 제안한 전력선 통신의 변조기법은 현재 무선 LAN에서 보편화된 변조방식으로 적용되고 있는 IEEE 802.11b의 CCK(Complementary Code Keying) 변조 방식이다. 채널 모델링은 댁내 전력선망을 기준으로 $10kHz{\sim}30MHz$ 대역에서의 전력선로 및 가정용 부하 특성에 기초한 모델링을 하였고 전력 계통 과도해석 소프트웨어인 PSCAD로 채널 모델을 구성하여 홈네트워크 환경에서의 전력선 통신의 신호 특성을 분석하였다.

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A Study on the High Speed Characteristics of Plastic Mould Steel using Ball End Mill AlTiN Coated Layers (볼 엔드밀 AlTiN코팅 층수에 따른 플라스틱금형강의 고속가공에 관한 연구)

  • Lee, Seung-Chul;Cho, Gyu-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.1
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    • pp.81-86
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    • 2010
  • This paper investigated into process characteristics of AlTiN coated layers for machining to the direction of upper and lower in plastic mold material (KP-4) with the cemented carbide ball endmill with the diameter of 8mm coated AlTiN layers (1~4) step by step using machining center. The material used in experiments was KP-4 that was machined by three types of inclined angles; $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ As estimated mechanical properties of AlTiN coated layers, it was shown the most result in the condition of three layered coating that the coating that the coating depth, the hardness of the coated layer and the surface roughness of the coated layer were $13{\mu}m$, Hv 3027.3 and $0.042{\mu}m$, respectively. The cutting component was better at the condition of upper direction than that of lower direction in all experimental conditions and indicated to be less which the bigger angle of the material was increased the effective diameter of the tool.

QAM Transmission of Multi-Code CDMA (멀티 코드 CDMA의 QAM 전송)

  • Ju Min-Chul;Hong Dae-Ki;Kim Young-Sung;Kim Sun-Hee;Kang Sung-Jin;Cho Jin-Woong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.4 no.1
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    • pp.37-44
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    • 2005
  • 본 논문에서는 멀티 코드 CDMA(Code Division Multiple Access)시스템에서 고속의 멀티미디어 서비스를 지원하기 위해 정보 데이터열을 QAM(Quadrature Amplitude Modulation) 부호화하는 방법을 제안한다. 송신 구조는 입력 비트를 정진폭 다중부호 이진직교 변조(Constant amplitude code biorthogonal modulation: 이하 CACB라 칭함)로 부호화하여 전송 심볼의 크기를 일정하게 하고 이렇게 이진화된 신호를 QAM 부호화하여 전송속도를 높인다. 복조기의 구조는 수신된 신호로부터 QAM 연판정기 블록을 거쳐 생성된 신호를 CACB 복호화기를 거쳐 데이터를 복조해 낸다. 제안된 시스템은 기존의 멀티 코드 방식에 비해 대역폭 효율을 크게 개선시킬 수 있어 전송 속도를 많이 향상시킬 수 있고, 멀티 코드 방식을 기반으로 하기 때문에 디지털 가전기기나 3세대 이동통신과, WPAN과 관련된 무선 네트워크 응용과 같은 미래의 고속의 무선 멀티미디어 서비스를 지원하기에 적합하다.

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New Database Table Design Program of Real Time Network for High Speed Train (한국형 고속 전철의 실시간 네트워크를 위한 새로운 데이터 테이블 설계 프로그램)

  • Cho, Chang-Hee;Park, Min-Kook;Kwon, Soon-Man;Kim, Yong-Ju;Kim, Sung-Shin
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1338-1340
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    • 2003
  • 현재의 공장 자동화, 국방, 항공, 철도, 금융 등을 포함하는 실시간 시스템은 여러 개의 컴퓨터가 다수의 장소에서 서로의 데이터 교환을 통한 협동 작업으로 여러 가지 기능 및 업무를 수행한다. 이는 마치 멀티프로세서를 가진 컴퓨터같이 생각할 수 있으며 이와같은 시스템에 있어서 업무 수행의 효율은 각 프로세서의 계산 능력에 비례함과 동시에 각 노드간의 데이터 전송 능력에 비례한다고 할 수 있다. 이와 같은 실시간 시스템이 올바르게 동작하기 위해서는 한정된 시간 내에 일정한 양의 데이터의 전달을 확정적으로 보장해 줄 수 있는 네트워크를 필요로 하는데 이를 실시간 네트워크(Real time network)라고 한다. 현대의 분산제어 시스템에 있어서 확정적인 시간 내의 데이터 전달은 전체 제어 시스템의 응동 특성에 중요한 요인이 된다. 본 논문은 한국형 고속 전철의 시제차(Prototype train)에 적용된 국제 표준 실시간 네트워크인 열차 통신 네트워크(Train Communication Network)에 관련한 내용이다. 실시간 네트워크는 실시간성을 보장하기 위해서 상호 교환될 데이터가 필요에 따라(온라인 상에서) 변경되는 것이 아니라 오프라인 디자인의 결과로 미리 결정되어진다. 즉 통신장치 사이에 전달되는 네트워크 데이터는 미리 설계된 네트워크 테이블을 기초로 정해진 시간에, 정해진 데이터가, 정해진 방식으로 전달되어 진다. 본 논문에서는 실시간 네트워크의 오프라인 설계를 하기 위한 도구로서 개발되어진 네트워크 데이터 테이블 작성 프로그램에 대해서 설명한다.

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The development of wheel-rail contact module for the next generation express train (차세대 고속철 해석을 위한 훨레일 모듈 개발)

  • Yoon, Ji-Won;Park, Tae-Won;Lee, Soo-Ho;Cho, Jae-Ik
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.225-230
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    • 2009
  • From the view point of railway vehicle dynamics, the interaction between wheel and rail have an huge effect on the behavior of the vehicle. This phenomenon is an unique motion, only for railway vehicles. Furthermore, close investigation of the backgrounds of the interaction is the key to estimate the dynamic behavior of the vehicle, successfully. To evaluate the model including flexible bodies such as car body and catenary system of the next generation express train, it is necessary to develop proper dynamic solver including a wheel rail contact module. In this study, wheel-rail contact module is developed using the general purpose dynamic solver. First of all, the procedure for calculation of the wheel-rail contact force has been established. Generally, yaw angle of the wheelset is ignored. Sets of information are summarized as tables and splined for further uses. With this information, normal force and creep coefficient can be extracted and used for FASTSIM algorithm, which has been shown good reliability over years. Normal force and longitudinal, lateral force at the contact surface are also calculated. Those data are verified by commercial railway simulation program 'VAMPIRE'. This procedure and program can offer a basic process for estimation of the dynamic behavior and wear of the wheel-rail system, even while running on the curved rail. Finally, multi-dimensional inspection tool will be developed including the prediction of the derailment.

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A Study on the Characteristics of Environmental Impact in Construction Sector of High-Speed Railway using LCA (LCA를 이용한 고속철도 건설단계에서의 환경부하 특성에 관한 연구)

  • Lee, Cheol;Lee, Jae-Young;Jung, Woo-Sung;Hwang, Young-Woo
    • Journal of the Korean Society for Railway
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    • v.17 no.3
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    • pp.178-185
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    • 2014
  • This study investigates the characteristics of environmental impact from the construction phase of a high-speed railway through a Life Cycle Assessment method based on the materials used and the energy consumption of the equipment used according to the design statement. The results reveal that the contributions to environmental impact in the construction sector of a high-speed railway were 89% for civil engineering, 7% for the track system, 2% for stations and 2% for the energy and telecommunication system. In particular, the highest contribution to the impact in the civil engineering category were 54% for Global Warming, 25% for Abiotic Resource Depletion and 8% for Photochemical Oxidant Creation. The main influence factors were the use of remicon and cement. In future, the application of Life Cycle Assessment for the construction sector of railway construction will introduce efficient reduction methods according to the quantitative calculation of environmental impact.