• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.351-354
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• 2002

The new enhanced method of temperature control need not any reference temperature, the system itself can find the melting temperature of gallium as a reference point by dithering input heat flux. If gallium is in melting state, the latent heat of fusion works, so gallium temperature does not change on dithering input heat flux. Also, the control method can determine the state of gallium; solid, liquid, or melting state by investigating the temperature in gallium. We apply this new temperature stabilization method to stabilize a Fabry-Perot cavity, which serves as a ultimate length measurement technique. We achieved 1 mK-temperature stability and 1.5426 nm/ 95 mm-length stability over 10 hours.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1850-1852
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• 1997

In this paper, the behavior and effect of conducting particles in a $SF_6$ insulated electrode system, are presented. It is shown that the bouncing voltage of the particle is independent of particle length, and that the breakdown voltages are affected by the particle length. The longer the particle, the lower the breakdown voltages. The bouncing-off, the lift off and breakdown voltages increase as the particle diameter increase. The breakdown voltage of free particle is lower than fixed particle on the enclosure.

• International Journal of Reliability and Applications
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• v.18 no.1
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• pp.1-8
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• 2017

In this paper, we study an extended warranty model under minimal repair-replacement warranty (MRRW) which is suggested by Park, Jung and Park (2013). Under MRRW policy, the manufacturer is responsible for providing the minimal repair-replacement services upon the system failures during the warranty period. And if the failure occurs during the extended warranty period, only the minimal repair is conducted. Following the expiration of extended warranty, the user is solely responsible for maintaining the system for a fixed length of time period and replaces the system at the end of such a maintenance period. During the maintenance period, only the minimally repair is given for each system failure. The main purpose of this article is to suggest the extended warranty and replacement model with MRRW. Given the cost structures incurred during the life cycle of the system, we formulate the expected cost and the expected length of life cycle to obtain the expected cost rate.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.540-545
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• 1997

An analytical and experimental investigation has been performed on the heated length-to-diameter effect on critical heat flux for fixed exit conditions. A L/D correction factor is developed by applying artificial neural network and conventional regression techniques to the KAIST CHF data base. In addition, experiment is being performed to validate the developed L/D correction factor with independent data. Assessment shows that the developed correction factor is promising for practical applications.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.4
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• pp.360-366
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• 2005

In the past, when there were few vehicles on the road, the T.O.D.(Time of Day) traffic signal worked very well. The T.O.D. signal operates on a preset signal cycling which cycles on the basis of the average number of average passenger cars in the memory device of an electric signal unit. Now days, with increasing many vehicles on restricted roads, the conventional traffic light creates startup-delay time and end-lag-time. The conventional traffic light loses the function of optimal cycle. And so, $30-45\%$ of conventional traffic cycle is not matched to the present traffic cycle. In this paper we proposes electro sensitive traffic light using fuzzy look up table method which will reduce the average vehicle waiting time and improve average vehicle speed. Computer simulation results prove that reducing the average vehicle waiting time which proposed considering passing vehicle length for optimal traffic cycle is better than fixed signal method which doesn't consider vehicle length.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.105-111
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• 2003

This paper is researching the storing of 40 different kinds of conditions. Such as, car speed, delay in starting time and the volume of cars in traffic. Through the use of a central nervous networking system or AI, using 10 different intersecting roads. We will improve the green traffic light. And allow more cars to easily flow through the intersections. Now days, with increasing many vehicles on restricted roads, the conventional traffic light creates prove startup-delay time and end-lag-time. The conventional traffic light loses the function of optimal cycle. And so, 30-45% of conventional traffic cycle is not matched to the present traffic cycle. In this paper proposes electro sensitive traffic light using fuzzy look up table method which will reduce the average vehicle waiting time and improve average vehicle speed. Computer simulation results prove that reducing the average vehicle waiting time which proposed considering passing vehicle length for optimal traffic cycle is better than fixed signal method which dosen't consider vehicle length.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.700-709
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• 2009

FBG sensor system is applied to the concrete lining structure in Taegu subway. Near the structure, the power cable tunnel construction started. We wanted to measure the deformation of the structure due to the construction by the FBG sensor. The applied sensor has the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

• Journal of the Korean Society of Costume
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• v.5
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• pp.185-196
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• 1981

This study concerns Jeugo-ris' collar patterns according to the pictures of the actual measurement of the bequests in Yi dynasty. In early Yi dynasty not only outside collar but also inside collar was the Mog-pan collar. In middle Yi dynasty many Jeugo-ris' bequests has been discovered. The form of the collar was various In before and after the 1590's, the Mog-pan collar and Kal-collar, Dang-ko callar was coexisted. But after the 1700's Jeugo-ris' collar pattern was fixed to the Dang-ko collar. In early and middle Yi dynasty the width of the collar was three or four times as wide as it on these days. In late Yi dynasty the inside collar length was longer than the outside collar length and the width of the collar was gradually narrow. The same thing as the form of the collar on these days had been appeared from the 1900's.

• Journal of the Korean Society of Safety
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• v.11 no.2
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• pp.89-95
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• 1996

To predict the service life of an organic vapor respirator cartridge, the breakthrough curve of respirator was simulated using a fixed-bed adsorption model and compared with that of sampling tube. And the effects of bed porosity, length to diameter ratio and flow rate of the sampling tube were studied. The life time of respirator cartridge was increased with the decrease of particle size and bed porosity. And the breakthrough time of sampling tube was affected by the flow rate, however not by the length to diameter ratio. The 10% breakthrough time of the sampling tube was corresponded with that of cartridge.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.2
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• pp.197-202
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• 2001

The biomechanical analysis of the load carrying effect on different floor surfaces has been conducted. Four different floor surfaces were prepared for ten subjects with each walking at a fixed velocity(1.33 m/sec) while carrying five different loads. The results showed that because of the significant interaction effect between floor slipperiness and the load carrying task, the load carrying effect should be analyzed according to different levels of the floor slipperiness, especially contaminant floors. On oily surfaces, slip distance(SD) and heel velocity (HV) increased whereas stride length(SL) decreased as load increased. In other words, significantly longer SD, faster HV, and no normal gait were found as load increased. As a result, a different protocol should be applied to measure floor slipperiness on oily floors as compared to dry surfaces for tribological approach.