• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.273-278
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• 2001

The transmission system of high speed train serve in the severe condition compared with those of other trains, namely, they have to transmit high power to run with high speed and they have to make maximum use of the limited space. To clarify the strength of gear for Korea High-speed train, a bending fatigue test is performed for the output gear of axle gear reduction unit. This paper reports the reviews of bending fatigue strength test method and the test results of output gear of axle gear reduction unit for high speed train.

• 대한전자공학회논문지SD
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• 제37권7호
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• pp.50-57
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• 2000

본 논문에서는 고속 FPGA 설계를 위한 논리 수준의 조합회로 합성 알고리듬을 제안한다. FPGA는 현장에서 직접 제작이 가능하고 제작 시간이 짧으며 제작 비용이 저렴하므로 초기 prototype 시스템의 제작에 자주 사용되고 있으나, ASIC 칩에 비해 지연시간이 크고 집적도가 떨어지는 단점이 있다. 제안된 알고리듬은 회로의 지연시간을 줄이기 위해 critical path를 분할한 후 분할된 회로를 동시에 수행하는 구조의 회로를 생성한다. MCNC 표준 테스트 회로에 대한 실험에서 제안된 지연시간 최적화 알고리듬이 기준 알고리듬에 비해 지연시간이 평균 19.1% 감소된 회로를 생성함을 보였다.

• 산업기술연구
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• 제20권B호
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• pp.9-14
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• 2000

Sound insulation performance is investigated on the corrugated panel used for a rail way vehicle. Random incidence sound transmission loss is calculated by using the equivalent orthotropic plate model. Analysis results on several kinds of corrugated panels are in good agreement with the measured data. The analysis method is applied to predict the sound transmission loss of the corrugated panel used for Korean high speed train.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.337-340
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• 2002

In data transmission at the digital satellite broadcasting systems, the delay and spread are caused whit receiving original signals from the transmitter in the receiver. So, there are some problems in data fast transmission. Also, transmitted signals ate received in stale of the combination of transmission delay and noise of channel. The affect of channel noise is reduced when increasing transmission power, but as signal interference due to the transmission delay and spread of channel increase in proportion to the transmission power, there is a problem in spite of increasing the transmission power. And there is the problem to add ISI(inter symbol interference) because the property of the channel is limo-varying due to relative moving in the transceiver Therefore, in this paper, a pulse shaping filter for the high-speed service in digital satellite broadcasting systems was designed and reduced the ISI.

• 산업경영시스템학회지
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• 제32권1호
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• pp.34-43
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• 2009

In this thesis, we explain developing processes of the power transmission system for lift truck. Conventional power transmission system had some problems such as spatial constraints or low speed and high torque problem. Because conventional power transmission system was mainly designed for high speed vehicles. In this paper we developed power shift drive axle specialized for $2.0{\sim}3.5$ ton lift truck. Innovative structure of transmission which is built in inside axle, enables to reduce system weight and size by 40% compared to the conventional power transmission system. Also, it is possible to do additional functions such as auto parking system and anti-roll back system.

• 전자공학회논문지S
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• 제35S권7호
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• pp.14-21
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• 1998

In providing with low speed multimedia services, a call blocking rate is greatly varied according to the transmission rate, and thereofr, the call blocking rate is remarkably increased for a service having a high transmission rate compared to a service having a low transmission rate. This paper presents three methods of solving this problem; Packing Scheme in which available channels distributed to each frequency channel are concentrated on one frequency channel and a call having a high transmission rate is assigned to the frequency channel; Queuing Scheme in which queuing is assigned to calls under service is temporarily reduced and a call having a high transmission rate is allowed. The result of performance analysis for 13 Kbps and 128 Kbps service through computer simulation showed that the call blocking rate for 128 Kbpx service was reduced by tens of percent accoring to loads.

• 한국정보통신학회논문지
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• 제5권7호
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• pp.1361-1373
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• 2001

3계층 클라이언트/서버 시스템에 일반적인 방화벽을 설치하면 어플리케이션의 서버와 방화벽의 프락시 기능이 중복되어 전송속도 저하 철상이 야기된다. 따라서, 본 논문에서는 어플리케이션 서버의 프락시 기능을 정의하고 네트워크 인터페이스 카드를 어플리케이션에 추가로 장착하여 듀얼-홈드 게이트웨이를 구성하고, 어플리케이션을 보호하기 위하여 외부망과 내부망으로 분리하는 스크린드 라우터를 설치하여 스크린드 서브넷 게이트웨이를 구성하는 침입차단 시스템을 제안하였다. 본 논문에서 제안된 시스템은 3계층 클라이언트/서버 시스템에 방화벽을 설치하는 것보다 네트워크의 통신량 분산에 효과적이며, 중복된 기능을 하지 않기 때문에 고속전송이 가능하다. 또한, 방화벽 구입에 대한 비용 효과도 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.62-69
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• 2003

In recent years, data transmission using power lines has been much highlighted. Power line is known to be cost-effective communication medium because the entire cable infrastructure has been already established and it is entirely connected with any home. Recently, the target of researches is to communicate data reliably over power lines at the speed of at least 1Mbits/s over the frequency range from 1MHz to 10MHz. OFDM communication system has been used for the high speed data transmission. Next, the conventional and adaptive OFDM systems for high speed data transmission over power line channel are investigated. The performance of AOFDM(adaptive OFDM) over the frequency selective channel with impulsive and narrow-band noise are studied to be a nice solution for high speed data transmission over power lines. The simulation results show that data the rates of the AOFDM are improved about 47% more than the ones of the conventional OFDM over the frequency response of case 4. In the results, the data rate has been much improved by the proposed adaptive algorithm in the frequency selective channel.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.467-473
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• 2005

A continuously variable transmission (CVT) with an inner spherical traction drive was conceptually designed for bicycle usage. The range of the overall speed ratio is from 1.0 to 4.5. The rated power and pedal speed are 100 Watts and 6 rad/s, respectively. The peculiar packageability, high-level power efficiency and high torque capacity were considered in the design process. A compact CVT that can be installed within a $244\times125\times160mm^3$ space and is above 0.9 in efficiency for the rated values was numerically designed. The distribution of efficiency according to the input torque and input speed were calculated. Gradeability in the prescribed operation mode was simulated.

• 전자공학회논문지
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• 제50권4호
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• pp.73-80
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• 2013

본 논문에서는 전송선의 정확한 고주파 특성화를 위해 실험적 접근을 기반으로 한 회로모델을 제안한다. 측정 시 불가피하게 발생하는 공진현상으로 인하여 배선의 길이에 상응하는 공진주파수에서 특성 임피던스 및 전파상수를 정확히 결정하기 어렵다. 따라서 물리적 통찰 및 이론을 바탕으로 이러한 공진효과가 배제된 전송선 파라미터 결정 방법이 제시되었다. 또한 고속신호의 전파 특성화를 위해 실험적으로 결정된 파라미터를 사용한 고주파 회로모델이 제안되었다. 본 논문에서 제안한 주파수 종속 전송선 파라미터 모델은 측정을 통해 검증되었으며, 고속 신호의 전파 특성화에 유용하게 적용될 수 있다.