• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1244-1247
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• 2002

The blending brake is mixed brake system which is operated by electrical and mechanical brake simultaneously. Most of urban transit system is used with blending brake unit. In order to train is align at the stopping position. The blending brake shall be presicely operated to the train. Many parameters are influence on the train when train is stopped on presicion position by blending brake. It is considered such parameters as decceleration, variable load, jerk, friction cofficient, etc. Therefore, This paper consider the parameter and describes the blending control for standard EMU. The control algorithm of it is proposed and simulation of it carried out by using MATLAB. Also Electronic control unit is manufactured with micro procesor which is configured fot blending control and is verified by performance test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1330-1332
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• 1994

In order to investigate the properties of electrical conduction and space charge in crosslinked polyethylene film, we were observed the specimen with 200[${\mu}m$] thickness. The electrical conduction properties of specimen were measured temperature range from 30 to $110[^{\circ}C] $as well as $10^{-2}$ - 1 [MV/cm] of electric field. The investigations on influence of space charge were carried out at room temperature and $60 [^{\circ}C]$.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.491-497
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• 2005

Brake system is indispensible functional part to the transportation machines such as railroad cars, and all of industrial machines. It is mechanical element to stop the movement or slow the speed, transforming kinetic energy of motion object into thermal energy through solid friction. According that recently the railroad cars have become high-speed, the technique in braking domain to secure the overall braking effort is making rapid progress. In particular, material development and manufacturing process are so important to secure friction performance, which is the core in braking performance of mechanical brake units. Wear of brake disk could mainly result in the diminishment of its life span due to thermal cracking, so the endurance against high temperature is required. On the other hand, in this case, the problem is that the side wear of pad, relative material is slightly increased because of enlargement of plastic deformation. It is necessary, therefore, to develop a disk material that will be used in the Tilting System mechanical brake units. The purpose of this paper is to make a study prior to developing brake disk of Tilting Train travelling at 200km/h and to propose the component of brake disk. Accordingly, I will conduct sufficient researches on technical documents of brake disk, that are basic documentations, analyze an impact on components, and further, considering braking degree of train, study for the basic proposal on brake disk's component of the train travelling at 200km/h, which has relatively minor influence of heat stress and maintains the friction. In this respect, I would like to investigate friction characteristics between disk and relative friction material via Test on some possible test segments, analyze and propose friction performance, temperature impact and so forth coming from the contact with pad, relative material to demonstrate the friction characteristics.

• Tribology and Lubricants
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• 제30권3호
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• pp.177-182
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• 2014

To stop a high speed train running at the speed of 300 km/h, the disc brake for the train should be able to dissipate enormous kinetic energy of the train into frictional heat energy. Sintered pin-type metals are mostly used for friction materials of high speed brake pads. A pad comprises several friction pins, and the topology, length, flexibility, composition, etc. have a great influence on the tribological properties of the disc brake. In this study, the topology of the friction pins in a pad was our main concern. We presented the optimization of the topology of a railcar brake pad with nine-pin-type friction materials by thermo-mechanical contact analysis. We modeled the brake pad with/without a back plate. To simulate a continuous braking, the pad or friction materials were rotated at constant velocity on the friction surface of the disc. We varied the positions of the nine friction materials to compare the temperature distributions on the disc surface. In a non-optimized brake pad, the distance between two neighboring friction materials in the radial direction from the rotational center of the disc was not equal. In an optimized pad, the distance between two neighboring friction materials in the radial direction was equal. The temperature distribution on the disc surface fluctuated more for the former than the latter. Optimizing the pad reduced the maximum temperature of the brake disc by more than 10%.

• 한국지반환경공학회 논문집
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• 제24권11호
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• pp.41-49
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• 2023

본 연구에서는 토사가 혼합된 암성토 제방의 침하 특성을 분석하기 위하여 실트질 재료 혼합에 따른 토사재료의 물리적 특성을 확인하고, 토사재료 혼합 비율에 따른 자갈재료의 압축특성을 분석하였다. 이를 위하여 사질토에 실트질 재료를 혼합하여 토사재료의 압축특성을 분석하였으며, 도상자갈과 유사한 입도분포를 갖는 암성토 재료에 다양한 비율의 토사를 혼합하여 지반을 조성하고 중형챔버를 이용한 일차원 압축실험을 수행하였다. 실험결과, 혼합토사 재료의 경우 Transition Fine Content(TFC)는 하중 조건에 따라서 21~26% 범위로 나타났으며, 토사가 혼합된 암성토 재료의 경우, 자갈 시료 내 토사의 공극 채움비율이 증가함에 따라 총압축량과 크리프 압축이 모두 감소하다가 50% 혼합비 이후에는 다시 침하량이 증가하는 것으로 나타났다.

• 한국철도학회논문집
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• 제17권3호
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• pp.178-185
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• 2014

본 연구에서는 국내 고속철도노선 전과정 중 건설단계에 대하여 각 분야별(토목, 궤도, 건축 및 전철전력/신호통신분야) 주요 건설자재 및 중장비 에너지 사용량을 토대로 전과정평가(Life Cycle Assessment, LCA) 방법론을 적용하여 주요 환경부하 특성을 분석하였다. 그 결과, 분야별 환경영향 기여도는 토목분야가 약 89%로 가장 높게 나타났으며, 궤도 7%, 건축 2%, 전철전력분야 2% 순으로 나타났다. 가장 기여도가 높은 토목분야의 경우, 주요 영향평가 범주는 지구온난화, 자원고갈, 광화학산화물생성으로 각각 54%, 25%, 8%로 나타났으며, 주요 영향인자는 레미콘과 시멘트인 것으로 분석되었다. 향후 철도 건설단계에서의 전과정평가 적용은 정량적인 환경부하 산정을 통해 효율적인 저감방법을 도입할 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1963-1969
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• 2009

This paper introduces method to estimate pollutant negative influence to polymer type insulator according to the international standard. To accomplish this goal, effective sample collecting method was surface was collected directly with the same dimension. Distilled Through this method pollute is easily and accurately collected. The second step is pollutant analysis. Several analyze item is selected such as quantity, conductivity, contact angle, Optical Microscope(OM), IR spectrometer(FT-IR), Equivalent Salt Deposit Density(ESDD), Thermal Analyzer(TA) and ICP-AES. The third step, best represent tunnel was selected considering location, length and natural surroundings. Also to consider the difference at inside the tunnel, several bracket insulators were selected along to the location. To make the result precise, above procedure was repeated several times at the same target. Finally relation among type of train, numbers of movement, surroundings, length will be considered in combination with the pollution. With this result pollute map for KORAIL could be accomplished and inspect period will be optimized case by case.

• 한국철도학회논문집
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• 제19권5호
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• pp.565-575
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• 2016

철도차량 영업 운행 중 빈번히 발생하는 차륜 마모, 손상 등의 결함을 제거하기 위하여 실시되는 차륜 전삭 공정과 관련하여 전삭 전후의 차량 동적성능을 분석하였다. 전동차를 대상으로 차륜 전삭 전후의 차륜답면형상을 계측, 분석하였으며 진동 및 승차감 특성을 분석하고자 차량 주행시험을 실시하였다. 시험결과, 차륜 전삭 후 차량 진동 RMS값은 전삭 전에 비하여 저감되었으며 철도차량 기술기준에 의거 분석한 차체 진동성능은 전삭 전에 비하여 개선되었다. 승차감레벨은 전삭 전에 비하여 전삭 후 좌우, 상하방향 모두 최대 약 3dB의 개선 효과를 보였으며 주행안전성 또한 개선됨을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.491-493
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• 2000

The performance of insulate materials gets worse with stress time in power system and because this causes lowering of function and accidents in equipment, development and performance improvement of excellent insulate materials are needed to make stable system. In this paper, to study the influence of degradation in XLPE, inner semiconducting layer and outer semiconducting layer, we studied dielectric characteristics at temperature $25{\sim}100[^{\circ}C]$ and frequency $20{\sim}1[MHz]$ and volume resistivity at temperature $25{\sim}100^{\circ}C$, voltage.

• 화약ㆍ발파
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• 제32권2호
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• pp.16-24
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• 2014

본 시공사례는 "중앙선 원주~제천 복선 전철 제 ${\bigcirc}$공구 노반 건설공사" 중 고속도로 하부통과 구간으로서 터널 노선 상부 13m에 운행 중인 고속도로가 있다. 고속도로에 영향을 최소화하기 위하여 무진동 암파쇄 굴착공법이 적용되었으나, 기계식 굴착작업 특성상 굴착 자체에 많은 시간이 소요되어 신속한 터널 폐합이 이루어지지 못해 굴착 중 주변 암반의 변위 증가에 따른 상부 침하가 우려되어 대안공법의 필요성이 요구되었다. 따라서 고속도로의 진동허용기준인 1.0cm/sec 이하로 제어하면서, 터널의 신속한 굴착과 폐합을 통해 지반의 변위를 최소화하여 상부 고속도로의 침하 현상을 방지할 수 있는 전자발파공법(eDevII)이 검토되었다. 사전 굴착영향검토를 시행한 결과, 전자발파를 통해 상부 고속도로의 안정적인 관리가 가능한 것으로 검토되었으며, 이를 기초로한 시공 결과 안전하고, 신속하게 굴착을 완료하였다.