• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.123-130
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• 2009

Motion estimation (ME) plays an important role in digital video compression. But it limits the performance of image quality and encoding speed and is computational demanding part of the encoder. To reduce computational time and maintain the image quality, integer pel and fractional pel ME methods are proposed in this paper. The proposed method for integer pel ME uses a hierarchical search strategy. This strategy method consists of symmetrical cross-X pattern, multi square grid pattern, diamond patterns. These search patterns places search points symmetrically and evenly that can cover the overall search area not to fall into the local minimum and to reduce the computational time. The proposed method for fractional pel uses full search pattern, center biased fractional pel search pattern and the proposed search pattern. According to block sizes, the proposed method for fractional pel decides the search pattern adaptively. Experiment results show that the speedup improvement of the proposed method over Unsymmetrical cross Multi Hexagon grid Search (UMHexagonS) and Full Search (FS) can be up to around $1.2{\sim}5.2$ times faster. Compared to image quality of FS, the proposed method shows an average PSNR drop of 0.01 dB while showing an average PSNR gain of 0.02 dB in comparison to that of UMHexagonS.

• Journal of the Korean GEO-environmental Society
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• v.12 no.4
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• pp.33-41
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• 2011

In case of building up port facilities on soft ground, unsymmetrical surcharge of embankment, which make the excess pore water pressure to increase, causes to occur lateral displacement due to plasticity of soil. A study on lateral displacement and settlement of the caisson, which is installed on improved ground, was accomplished. The field measurement data and calculated values obtained from FEM program of Plaxis were compared and analyzed. For numerical analysis, the properties of soils, constructions stage and time were considered. Lateral displacement was measured at the point of inclinometers installed in front of caisson. Settlement was measured at the center of extra embankment behind of caisson. Comparison of measured and calculated for lateral displacement showed that the calculated value was greater than the measured, and increasing trend was different. The calculated value showed step increasing as step extra embankment applied, whereas the measured gradually was increased. For settlement of embankment, the amount of both measured and calculated were similar, but the trend was different like that of lateral movement.

• Journal of the Korean Geotechnical Society
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• v.24 no.6
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• pp.5-16
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• 2008

This study investigated the existing theoretical backgrounds in order to examine the stability control method of lateral flow caused by the Plasticity of soils when unsymmetrical surcharge works on polluted soils and then compared and analyzed the results measured through model tests. Ultimate bearing power of ML and $ML_{p1}$ and $ML_{p2}$ obtained at surcharge(q)-settlement$(S_v)$ curve showed similar trends to ultimate bearing power obtained from control chart of deflection $(S_v-Y_m)$ by Tominaga.Hashimoto, that of $S_v-(Y_m/S_v)$ by Matsuo.Kawamura and that of $(q/Y_m)-q$ by Shibata.Sekiguchi and so it is considered that it has no problem in actual applicability. ${S_v-(Y_m/S_v)}$ of control chart of $ML_{p1}$ by Matsuo.Kawamura showed smaller value than ultimate bearing capacity value from surcharge-settlement curve $(q-S_v)$. Expression of ML of fracture baseline at stability control charge by Matsuo Kawamura is ${S_v=3.21exp}\{-0.48(Y_m/S_v)\}$ and expression of $ML_{p1}$ is ${S_v=3.26exp}\{-0.96(Y_m/S_v)\}$ and expression of $ML_{p2}$ is ${S_v=6.33exp}\{-0.45(Y_m/S_v)\}$.