• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1079-1082
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• 2008

The HEMU-400X project starts last year. It is important first of all that describe correctly system requirement until configuration of system, design, manufacturing, installation and test verification so that the complicated high-speed electric multiple unit is to run safety and reliable and to achieve target performance and function properly. The system requirement assist the system designer to comprehensive the performance and function of system in basic design. This paper proposes the development methodology of system requirement for HEMU-400X.

• 한국철도학회논문집
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• 제3권1호
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• pp.27-33
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• 2000

In this paper, numerically evaluated is the crashworthiness of the new design of the standard Korea Electric Multiple Unit Train(K-EMU)[developed by the Korea Railway Research Institute]. The 4-car consist of K-EMU is analyzed under collision conditions such as normal coupling, heavy shunting, light collision and heavy collision to collide against another stationary one at 5 kph, 10 kph, 25 kph and 32 kph, respectively. Energy absorbing capacity of its draftgear commercially available in the market and to be equipped in K-EMU is evaluated under each collision condition. Analytical results show that draftgear only is not enough to provide necessary energy absorbing capacity. It is therefore concluded that additional energy absorbers like mechanical fuses should be adopted to improve the crashworthiness of K-EMU.

• 한국안전학회지
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• 제27권6호
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• pp.31-42
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• 2012

Urban transit vehicle that uses electrical energy, is faster, safer and energy-efficient public transit than other means. As a Research method, the Matlab/Simulink are used to modeling a regenerative brake-capable train, and actual parameters such as powering and braking characteristics, all kinds of resistance, passenger load, velocity, gradient, radius of curve etc and powering and breaking commands per time or distance are inputted to train's dynamic equation, then a simulation program is made and used to yield train driving pattern and driving time and the amount of driving energy used thereby at auto and manual operation and at all sector.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.395-400
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• 2009

The HEMU-400X project starts at 2007. It is important first of all that describing correctly system requirement during configuration of system, design, manufacturing, installation and test verification so that the complicated high-speed electric multiple unit is to run safety and reliable and to achieve target performance and function properly. The system requirement assist the system designer to understand the performance and function of system in basic design. For this process, system engineer have to manage the system requirement. This paper proposes the management contents of system requirement such as change management, requirement traceability, etc, for HEMU-400X.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.693-694
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• 2008

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 춘계학술대회 논문집
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• pp.318-323
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• 2006

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.69-72
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• 2004

There are an electronic and a manual type in Bidet. The electronic bidet has some advantages. it supplies multiple functions and is up easily. However, it has frequent defects and a high price. The manual bidet is not need to supply electric and is cheaper than the electronic type. However, it is needed to supply hot water and is hard to set up. In order to solve these defects, this study designed a bidet heating unit using an electric instantaneous water heating method. To get a proper heating elements, experiments were performed about a Ni-Cr heater and a film heater.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.3731-3735
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• 2015

국내 최초로 개발된 동력분산형 고속열차인 HEMU-430X의 최고속도시험 중 실시한 차량 중량과 가속성능간의 상관관계에 대해 보고한다. 차량의 출력을 일정하게 유지한 채, 차량에 중량물 설치 및 제거를 통해 전체 차량의 중량을 2% 변화시킬 때의 차량 가속성능을 분석한 결과, 시험 최고속도인 413km/h속도 영역에서는 중량이 가벼울 때 최고속도시험에 유리한 것으로 나타났다. 시험 종료 후, 시험 당시 0.1초 단위로 측정된 속도 데이터를 바탕으로 속도별 차량의 추진에 사용된 소비전력을 측정한 결과 차량의 견인력과 공기저항력이 같아져서 더 이상 추진이 되지 않는 균형속도는 419km/h로 산출이 되었으며, 이는 중량이 가벼울 때 가속이 유리하다는 시험 결과와 일치한다. 이러한 분석 결과를 바탕으로 향후 HEMU-430X의 증속 시험에 활용할 계획이다.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.159-179
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• 2022

Often a network becomes complex, and multiple entities would get in charge of managing part of the whole network. An example is a utility grid. While the entire grid would go under a single utility company's responsibility, the network is often split into multiple subsections. Subsequently, each subsection would be given as the responsibility area to the corresponding sub-organization in the utility company. The issue of how to make subsystems of adequate size and minimum number of interconnections between subsystems becomes more critical, especially in real-time simulations. Because the computation capability limit of a single computation unit, regardless of whether it is a high-speed conventional CPU core or an FPGA computational engine, it comes with a maximum limit that can be completed within a given amount of execution time. The issue becomes worsened in real time simulation, in which the computation needs to be in precise synchronization with the real-world clock. When the subject of the computation allows for a longer execution time, i.e., a larger time step size, a larger portion of the network can be put on a computation unit. This translates into a larger margin of the difference between the worst and the best. In other words, even though the worst (or the largest) computational burden is orders of magnitude larger than the best (or the smallest) computational burden, all the necessary computation can still be completed within the given amount of time. However, the requirement of real-time makes the margin much smaller. In other words, the difference between the worst and the best should be as small as possible in order to ensure the even distribution of the computational load. Besides, data exchange/communication is essential in parallel computation, affecting the overall performance. However, the exchange of data takes time. Therefore, the corresponding consideration needs to be with the computational load distribution among multiple calculation units. If it turns out in a satisfactory way, such distribution will raise the possibility of completing the necessary computation in a given amount of time, which might come down in the level of microsecond order. This paper presents an effective way to split a given electrical network, according to multiple criteria, for the purpose of distributing the entire computational load into a set of even (or close to even) sized computational loads. Based on the proposed system splitting method, heavy computation burdens of large-scale electrical networks can be distributed to multiple calculation units, such as an RTDS real time simulator, achieving either more efficient usage of the calculation units, a reduction of the necessary size of the simulation time step, or both.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.169-174
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• 2012

Reduction unit is one of the most important components for railway vehicle because torque of motor must be transmitted to wheels of vehicle by reduction unit. However, According to advanced studies, it has been often broke down due to the damage, fatigue and wear of gear. To solve this problem, defect diagnosis methods of gear have been mainly using the vibration diagnosis technology through vibration waveform and frequency analysis. However, We should know vibration characteristics of normal state reduction unit prior to defect diagnosis. So in this paper, We had analyzed vibration characteristics of reduction unit in order to utilize monitoring system development. Comparison of targets is the vibration characteristics of normal state reduction unit about Electric Multiple Unit(EMU) and the High-speed trains(KTX, KTX II).