• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.45-50
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• 2006

Copper via filling is the important factor in 3-D stacking interconnection of SiP (system in package). As the packaging density is getting higher, the size of via is getting smaller. When DC electroplating is applied, a defect-free hole cannot be obtained in a small size via hole. To prevent the defects in holes, pulse and pulse reverse current was applied in copper via filling. The holes, $20\and\;50{\mu}m$ in diameter and $100{\sim}190\;{\mu}m$ in height. The holes were prepared by DRIE method. Ta was sputtered for copper diffusion barrier followed by copper seed layer IMP sputtering. Via specimen were filled by DC, pulse and pulse-reverse current electroplating methods. The effects of additives and current types on copper deposits were investigated. Vertical and horizontal cross section of via were observed by SEM to find the defects in via. When pulse-reverse electroplating method was used, defect free via were successfully obtained.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.377-382
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• 2017

Field experiments were conducted to estimate streambed hydraulic conductivity at 15 sites in the Anseongcheon watershed, Korea. Seepage meters and piezometers were installed in the streambed at each site to measure the amount of stream water-groundwater exchange and the hydraulic gradient. The vertical hydraulic conductivity was then calculated using Darcy's formula. The measured stream water-groundwater exchange rates were $4.08{\times}10^{-6}$ to $1.49{\times}10^{-5}m/s$, and the vertical hydraulic gradients were 0.005 to 0.145. The data suggest the streambed hydraulic conductivity to be $7.80{\times}10^{-5}$ to $1.58{\times}10^{-3}m/s$. The results show significant differences in connectivity between stream and aquifer. Quantification of the hydraulic interconnection between stream and aquifer, and evaluation of the effects of groundwater development and utilization on the streamflow require hydrogeological investigations of the connection between stream and aquifer, including the hydraulic conductivity of the streambed. Various field testing and analysis methods for hydrogeological assessment also require further improvement.

• Journal of Families and Better Life
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• v.26 no.2
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• pp.115-127
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• 2008

The purpose of this study was to examine the characteristics of change in the composition of indoor spaces in Korean-style houses which have been repaired and improved extensively through the 'Bukchon Improvement Project' and are being utilized for public purposes. For this, we conducted a field survey through visiting the house sites from the 5th to the 26th of May, 2006. Conclusions drawn from this study are as follows. Bukchon Korean-style houses maintain centripetal space composition, in which the rooms surround the court. Centering on the court, the hierarchy of spaces is determined, and the hierarchy of spaces and the composition of internal layout are restructured centering on the court and the main hall without change in direction and position. The main hall is sometimes converted to a room, but it maintains an open space relation with other spaces centering on the court, and therefore, even after its use has been changed, it is still the most Korean-style space. In addition, with floor heating, the common sitting-style life is maintained continuously although the rooms have been converted and standing-style furniture is used. In this way, publicly promoted policies for Korean-style houses are allowed within the limit that the appearance is maintained and the internal spaces do not change the overall structure. However, in order to maintain the tradition of Korean-style houses and utilize them as various spaces, the following supplementations are necessary. First, the main hall and the inner court of a Koreanstyle house should be utilized actively. The court sometimes keeps individuals' privacy or expands the space by extending the view to outdoor spaces, and is sometimes used as an open space through interconnection between the inside and the outside of the house. Second, consideration should be given to vertical spaces. Horizontal expansion causes a change of floor plan. Thus, space should be secured using various cross-sectional changes, such as a kitchen and a loft over the kitchen. Third, structure should be changeable in order to adjust the size of spaces. Thus, through research on traditional windows, we need to develop changeable walls that can be installed and removed easily according to the use of spaces.