• Journal of the Korean institute of surface engineering
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• v.19 no.3
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• pp.92-108
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• 1986

An electroplating on the lead frame fabricated from domestic copper plate was studied experimentally. In this study, nickel was plated on the thin copper lead frame and silver layer was coated on the nickel film in the cyanide electrolyte. The effect of process variables such as current density, plating time, coating thickness and flow rate of electrolytic solution on the properties of coating was investigated. Some samples on each step were fabricated during electroplating. The results obtained from polarization measurement, observation of SEM photograph, adhesion test of coating and microhardness test are as follows. On silver plating, polarization resistance of potentiostatic cathodic polarization curve is reduced as the flow rate of Ag electrolytic solution increases. And above resistance is also reduced when the minor chemicals of sodium cyanide and sodium carbonate are added in potassium silver cyanide bath. The reduced polarization resistance makes silver deposition on the cathode easy. An increase in the current density and the coating thickness causes the particle size of deposit to coarsen, and consequently the Knoop microhardness of the coating decreases. On selective plating an increase in the flow rate of plating solution lead to do high speed plating with high current density. In this case, the surface morphology of deposit is of fine microstructure with high Knoop hardness. An increasing trend of the adhesion of coating was shown with increasing the current density and flow rate of electrolytic solution.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.1
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• pp.81-84
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• 2004

A water-cooled calorimeter chamber with 8 cooling channels based on KSR-III sub-scale chamber has been designed and manufactured. One dimensional empirical correlation has been used at the design stage and full three-dimensional CFD analysis has been conducted to confirm the cooling condition for hot fire test is safe. Predicted heat flux is accurate around the nozzle throat when the thermal resistance of carbon deposit is considered. However relatively large difference is observed in chamber part.

• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.123-126
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• 2000

This study shows consolidation properties resulted from the experiment made on changes by load increment ratio and consolidation duration of standard consolidation test using deposit soil of Chungju Dam. Though the comparison and analysis of the result turned out that void ratio by load increment ratio was unchanged greatly, the result was inclined as followes : the smaller load increment ratio is, the bigger void ratio is, while the bigger load increment ratio is the bigger settlement is. Also coefficient of consolidation is increased in inverse ratio to load increment ratio. Coefficient of permeability is increased in proportion to load increment ratio, it is not fixed changes by consolidation duration, however. Degree of consolidation is increased to load increment ratio.

• Knowledge Management Research
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• v.18 no.1
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• pp.49-65
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• 2017

Financial products entail either gains or losses, and customers' psychological reaction to these gains and losses affect the selection of the financial products. This study explains the financial customers' behavior by introducing consumers' psychological variables such as loss aversion and construal levels. According to the construal level theory, people use more abstract and higher levels of construal to represent objects that are more distant on psychological distance. Based on extant research about loss aversion and construal levels, this study proposes two hypotheses and test the hypotheses. The experimental study examines how loss aversion affects the choice between deposit products and fund products in short-term and long-term investment situations. In the long-term condition the respondents prefer fund products to deposit products, whereas in the short-term condition the respondents have showed the opposite result. Also, the effects of loss aversion on preferences for financial products have interacted with the time horizon of investments. Implications and limitations are discussed to establish more effective marketing strategies based on the results of this study.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11b
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• pp.3-11
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• 1999

It has been said from previous studies that the preconsolidation pressure (p$\sub$c/)of Nangton Rive. deposit is considerably less than the in situ effective burden pressure (p'$\sub$$\upsilon$ο/). Question has risen whether this small pc vale is due to under consolidation or unsuitable laboratory test including low small quality. As a cooperative research program between PHRI (Port and Harbor Research Institute) and Pusan National University, an extensive soil investigation was carried out at a site of Yangsan, Pusan, using the Japanese sampler. It Is found that although p$\sub$c/ value at the site is slightly greater than p'$\sub$$\upsilon$ο/, its over consolidation ratio (OCR) is quite small compared with aged normally consolidated clay in Japan.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.163-170
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• 2006

By removing sacrificial layer through ashing process, movable MEMS structure on substrate can be fabricated in surface micromachining. However, MEMS structure includes, during the ashing process, the warping or buckling effects due to stress gradient along the vertical direction of thin film. In this study, we presented method for counteracting the unwanted deflection of MEMS structure and designed using character of deposit process to overcome limited design conditions. Unit cell patterns were designed with character of deposit shape, and their final shapes were adopted using Finite Element Method. Finally, RF MEMS switch was fabricated by surface micro machining as test vehicles. We checked out that alleviation effect for deformation of switch improved by 35%.

• Geomechanics and Engineering
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• v.13 no.6
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• pp.963-975
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• 2017

Improvement of soft clay deposit by preloading with vertical drains is one of the most popular techniques followed worldwide. These drains accelerate the rate of consolidation by shortening the drainage path. Although the analytical and numerical solutions available are mostly based on equal strain hypothesis, the adoption of free strain analysis is more realistic because of the flexible nature of the imposed surcharge loading, especially for the embankment loading used for transport infrastructure. In this paper, a numerical model has been developed based on free strain hypothesis for understanding the behaviour of soft ground improvement by vertical drain with preloading. The unit cell analogy is used and the effect of smear has been incorporated. The model has been validated by comparing with available field test results and thereafter, a hypothetical case study is done using the available field data for soft clay deposit existing in the eastern part of Australia and important conclusions are drawn therefrom.

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.245-247
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• 2001

In this study, the effects of dilution on the wear behavior of PTAW (Plasma Transferred Arc Welding) Inconel 625, Inconel 718 and Stellite 6 overlays on Nimonic 80A were investigated. Inorder to evaluate the wear performance, two-body and three-body abrasive wear test, and dry sliding wear test were performed. According to wear tests, the wear rate of deposit with dilution 30% was higher than that of dilution 10% by 10%, and it was also found the plastic deformation near worn surface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1181-1190
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• 2014

In this study, the erosional parameters for deposit beds were quantitatively estimated domestically for the first time through the erosion tests using an annular flume. Four erosion tests were carried out for the deposit beds with different consolidation structures, which were obtained by consolidating the kaolinite slurries for a given time durations. Results of erosion tests showed that the bed shear strength ${\tau}_s$ increased with the consolidation time and bed depth. The erosion rate ${\epsilon}$ was also shown to be related well with the excess shear stress ${\tau}_b-{\tau}_s$ which was given by the difference between flow shear stress ${\tau}_b$ and bed shear strength ${\tau}_s$. While the logarithm of the erosion rate was linearly related with the excess shear stress as ${\tau}_b-{\tau}_s{\geq}0.1N/m^2$, however, the erosion rate decreased rapidly with it when ${\tau}_b-{\tau}_s{\leq}0.1N/m^2$. These erosion test results were also shown to be good enough to verify by comparing with the test results from previous studies and a new equation was suggested to describe the erosion rate more well in the region of ${\tau}_b-{\tau}_s{\leq}0.1N/m^2$.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.117-122
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• 1999

Laboratory and field investigations of the coefficient of vertical and horizontal consolidation for Yangsan clay deposit were carried out using the conventional oedometer, Rowecell and piezocone test. Correlation among these test methods were also studied. In this paper, the relationship between vertical and horizontal consolidation were suggested such as C$\sub$h(Oed)/=0.75∼1.46 C$\sub$v(Oed)/, C$\sub$h(Rowecell) =1.95∼2.93 C$\sub$v(Oed)/, C$\sub$h(piezocone)/ =1.0∼5.0 C$\sub$v(Oed)/. As a result, a fair approximate estimations of C$\sub$h/ can be made by simple test using the conventional oedometer tests.