• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.12_13
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• 2009

Recently, TTX(Tilting Train eXpress) has operated test. Electric railways, including the TTX, have electric problems(harmonic etc) that could bring about serious accidents.. Thus, TTX's electrical problems also need leading studies because the new Korean TTX will operate earnestly in 2012. In this paper, electrical signals in TTX operation were detected to analyze electrical harmonic. The electrical harmonics considered operation modes triparted(coasting, acceleration, braking) were analysed and evaluated.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.234-234
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• 2006

Novel molecular glassy POSS-based material having carbazole moiety as a photo- and electroactive group was synthesized, and its thermal, morphological, electrochemical, and optical properties were investigated. POSS having carbazole (POSS-Cz) was found to form easily amorphous glassy film by cooling the melt sample or by spin coasting onto glass substrate. POSS-Cz showed monomeric emission even in solid film, which suggests that carbazole moiety can be isolated even in solid state.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.498-506
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• 2010

The neutral section was installed in order to prevent conflict with different phase angle source in electric railway catenary system. The speed of electric train reduced due to coasting operation by notch off when it passed the neutral section. And, the catenary wire was damaged and the accident might be happened because of the arc generation when the electric train passed the neutral section with notch on condition. This project has a goal to develop the automatic changeover system using by noncontactless semiconductor device in neutral section of catenary system so that the train pass as notch-on condition. In this first year, we obtain as following results such as domestic and international systems applications and completion requirements, development and analysis of stability for automatic changeover system, design of static switching device on automatic changeover system in neutral section and drawing up interface design and specifications according to equipment.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1878-1884
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• 2010

Currently in Korea, neutral sections in front of substations and sectioning posts are greatly divided into AC/DC sections and AC/AC sections. Considering catenary damage and safety issues trains pass crossover by coasting driving at notch-off. However in cases of Japan, China, or Taiwan, the usage of automatic crossover system makes it possible to pass at notch-on, enhancing high-speed railway operation for efficiency, and stability. These are the purposes of developing automatic power crossover system in neutral sections. This paper introduces two methods to detect the position of a train required to activate automatic crossover systems in neutral sections. The optimal method is expected in terms of the distance of neutral section.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1099-1100
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• 2006

The running of the electric train are done by powering, breaking and coasting. Powering to start and accelerate the rolling stock means driving the three-phase electric induction motors controlled by VVVF inverters which are connected to overhead power line directly(DC) or indirectly(AC, DC/AC). Breaking is achieved by blending control which is the proportional combination between regenerative breaking of VVVF inverter and air pressure control of breaking operating unit(BOU). Therefore, Data obtained during two operation are very important items to evaluate the running performance of RS. This paper has investigated in real time data acquired from VVVF inverter and measured by pressure sensor directly connected to air breaking line(motor car and trailer car). By analyzing data in the region of time and frequency, fundamental methods for eavaluating the running performance of RS quantitatively and objectively have been suggested.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.855-861
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• 2008

The development of fuel cell hybrid power system, as a next generation power system for solving the global warming, has been being made actively progress around passenger vehicles. Also, in case of railway vehicles in unelectrified railway line, the adoption of fuel cell hybrid power system is being studied around well-known manufacturers. This paper introduces both the configuration and the control strategy of fuel cell hybrid power system in order to apply to a light electronic railway vehicle having a repeated driving pattern of acceleration, coasting and deceleration and provides simulation results to evaluate their validity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.151-153
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• 2014

본 논문에서는 사회네트워크 분석 기법을 이용하여 2005년부터 2013년까지 운용되었던 국내 연안여객선의 항로를 분석하였다. 분석결과 연도별로 중심이 되는 항구가 변화되는 것을 확인할 수 있었다. 목포는 지속적으로 가장 높은 연결 중심성을 보였으며, 여수는 최근 그 중심성이 높아지는 것을 확인하였다. 또한 물동량과 이용량 등 전통적인 방법을 통하여 분석한 결과와 사회 네트워크 방법으로 분석한 결과 값을 비교하였는데 이 두 값이 매우 강한 상관관계를 보였다. 이를 통해 전통적인 방법을 사용하지 않더라도 네트워크 분석을 통해 해당 항구의 중심성을 알 수 있음을 확인하였다.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.299-300
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• 2007

In this paper, slip wear phenomenon of train was studied by traction force of acceleration and braking force of deceleration. First, the slip wear phenomenon on train operation mode was analyzed when powering, coasting and braking each and then rail wear was analyzed from the slip wear data. Especially, the data proved correlation between slip wear and deceleration rather than acceleration. Second, If velocity of a train is constant, even though the velocity is high, ATO logging data and measurement data proved that the rail wear is not serious. It will help for efficient braking force operation providing fundamental data to braking step control.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.96-102
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• 2000

Spinning mechanism is generally used in coasting process on grass plates. Rebounding PR(Photo Resist) which leads to occur inferiority of coating process is caused by vibrational energy of whole coating system. In this study, the sensitivity analysis is performed to analyze and reduce vibrational terms in the spin coating system. The sensitivity analysis is bared on the numerical expression of this system. By the bond graph method. power flow of each system is represented by some basic bond graph elements. Any energy domain system is modeled using the unified elements. The modelled spin coater system is verified with power spectrum data measured by FFT analyzer. As the results of verifying model parameters and sensitivity analysis, principal factors causing vibration phenomenon are mentioned. A study on vibration method in the spin coating system is discussed.

• Journal of the Korean Society of Safety
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• v.27 no.6
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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.