• International Journal of Automotive Technology
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• v.3 no.3
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• pp.117-122
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• 2002

Joint stiffness can affect the vibration characteristics of car body structures. Therefore, it should be included in vehicle system model. In this paper, a numerical approximation of joint stiffness is presented considering joint flexibility of thin walled beam-jointed structures. Using the proposed method, it is possible to optimize joint structures considering the change of section shapes in vehicle structures. The numerical approximation of joint stiffness is derived using the response surface method in terms of beam section properties. The study shows that joint stiffnesses can be effectively determined in designing vehicle structures.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.416-418
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• 2001

In the feeding system of electric railways it is necessary to divide the power lines for either ac or dc system. At this dead section, the system is damaged by the abrupt change of the coming-in power. This paper present the relationships. Between the feeding system and the trail-cars, and the counter plans to reduce the electrical arc and the breakdown at the dead section.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.155-163
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• 2001

Joint stiffnesses can affect the vibrational characteristics of car body structures and, therefore, should be included in vehicle system models. In this paper, a numerical approximation of joint stiffness is presented for considering joint flexibility of thin walled beam jointed structures. Using the proposed method, it is possible to optimize joint structures considering the change of section shapes in vehicle structures. The numerical approximation of joint stiffnesses is derived using the RSM(Response Surface Method) in terms of beam section properties. The study shows that joint stiffnesses can be effectively determined in designing vehicle structure.

• Korean Institute of Interior Design Journal
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• no.39
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• pp.45-53
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• 2003

The purpose of this study is to grasp how B la Bartok's 'Music for Strings, Percussion and Celesta' was expressed in 'Stretto House' of Steven Holl. In conclusion, it is found that phenonenological temporality was expressed through the following equation: (equation omitted). More specifically, it is clarified that the stretto of the musical piece was expressed in the spatial overlapping of the house; the inversion, in the form change of the plan and section of the guest house; the symmetrical proportion and Golden Section, in the same proportion of the house section; the melody of theme, in the shape of the roof. This shows the possibility of approach to the substance of interior and architectural design through music.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.11a
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• pp.291-305
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• 2003

In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with plant operation data demonstrates the effectiveness of the model identified.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.665-669
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• 2007

This study investigates the temperature change and thermal conductivity for the braking disc of the railway vehicle due to the types of train and service conditions. The temperature change was measured by non-contact Infrared thermometers. Average temperature was measured between $79.32^{\circ}C$ and $104.46^{\circ}C$ due to types of train and service section. In the same service section, the surface temperatures of Saemaul train were higher than Mugungwha train; the reason might have been the average service speed of Saemaul train (83km/h) was higher than Mugungwha train (107km/h), and the weight was similar 39t (Mugungwha) and 39.3t (Saemaul). But the maximum surface temperature was measured on the Mugungwha train; however the difference was not too big with the maximum temperature of Saemaul train. Also, the disc surface temperatures were changed due to the material of lining; metal and non-asbestos, on the same train and the same service section. In addition. the thermal conductivity was tested the thermal conductivities were increased by the increasing of the temperature. The change is too big between $100^{\circ}C$ and $200^{\circ}C$. But each average value is small. and the mechanical property change is very low. As a result, we conclude that this disc is suitable for usage between $100^{\circ}C$ and $300^{\circ}C$.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1077-1083
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• 2011

Turnout is one of railroad track components. The turnout is used to change train routes to near other sections when keeping the train speed. There are many accidents in the section including the turnout. The number of accidents and errors is 363 for ten years in the section including the turnout and annual average is 36.3. To ensure safety of the turnout, it is necessary to install monitoring systems. By using the monitoring systems, it is able to accumulate related information, develop maintenance and take a step for accidents in advance. Hence, The number of accidents and errors is decreased in the section including the turnout. So, when new turnout is installed, it is needed to use monitoring systems. Therefore, combined turnout management system is needed in Korea. It is possible to perform efficient maintenance because real-time monitoring system by using sensors and data-base management system. In this paper, accidents in the section including domestic turnout are analyzed and foreign combined turnout management system is presented. Hence, articles for installing the combined turnout management system in Korea are proposed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2125-2130
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• 2010

The neutral section on electric railway system is significant sector in order to prevent short circuit of two electric powers. However, while electric trains pass the neutral section, those speed is decreased and the accident of AC electric traction system and the electric train would be occurred. So the countermeasures are urgently needed. The automatic power switching technology system that is current being research and development is system to improve these problems. Because main object of this system is power change using static switch in the neutral section, it's expected to cause a variety of transients. Especially, onboard transformer inrush current for electric railway train can be occurred more than rated current according to switching time. Therefore, the analysis and improvement are needed to ensure the stability of this system. In this paper, we analyze the operating characteristics of the automatic power switching technology system. Especially, it reviews inrush current according to the closing phase angle. And we propose control plan of inrush current considering the case that voltage is maintained due to counter electromotive force and regenerative braking operation of electric railway train. Finally, the proposed control scheme was reviewed using the transient analysis program.

• Korean Institute of Interior Design Journal
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• v.14 no.6 s.53
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• pp.95-102
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• 2005

The purpose of this study was to analyze the ambiguity of the boundary through the composition of section. The building means the compose of the inside space by physical shell. Inside space that has boundary factors like floor, wall, roof and column is surrounded outside space. The factors which compose the boundary was expressed by architects as various analysis, but it has changed as changing of paradigm and information revolution. The inside space and outside space were connected through the system arrangement, so various space could construct by an aspect of relation. The history of architecture was written as the establishment of in-out space by architectural boundary factors, but the space could not divide definitely, composed complex structure, could experience various recognition. The existing study which is focused on Ambiguity of the Boundary is just focused on contemporary architecture. Ambiguity of the Boundary is developed by using glass. The transparency of glass removed the boundary of space, so it can be created free wall, continuity of view. It was Influenced the boundary of the sight and changed the expression of boundary between the space. This study is to analyze the change of boundary awareness and find the ambiguity of boundary in the section.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.13-18
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• 2003

Heat pipes with binary mixture fabricated and tested for applications where condenser temperature is in a range of $10^{\circ}C$ to $130^{\circ}C$. The pipe materials 8.0 mm O.D. cupper tube and the working fluids are ethanol-water mixtures. The total length of test of the heat pipe was 1710mm in which evaporator section was 1570mm, adiabatic section was 50mm and condenser section was 90mm. Mixing ratios of ethanol and water could be variable in mole fraction. Temperature of condenser section was $10^{\circ}C$, $80^{\circ}C$ and $130^{\circ}C$. Heat pipe performance experimental study was accomplished with change of mixing ratio in these temperatures. The fill charge ratio was 20% of the heat pipe volume. Wick structure was woven-wire and method of experimental work was that thermal load was increased 20W step until the heat pipe wall temperature reached at $150^{\circ}C$. Results were following: At coolant $10^{\circ}C$ and $130^{\circ}C$, mixing ratio that have beat thermal performance was 0.8M+ and at coolant $80^{\circ}C$, was 0.3 ${\sim}$ 0.5 M+.