• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.1-7
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• 2018

The number of construction of roads and railroads in soft ground such as coastal areas and wetlands is getting increased. For this reason cases that soft ground improvement is applied are increasing. In general, many ground improvement methods consider only the working conditions at the time or only economy. But if the working condition and economy are taken into consideration together, the number of applicable construction method gets limited. In such a case, a ground improvement method using both the surface layer portion and the deep layer portion is applied. But the basic research on this is still insufficient in practice. Therefore, in this study the reinforcement effect of geogrid was investigated by carrying out the model test realizing the case in which soft surface ground improvement and depth improvement are simultaneously applied. And it was intened to understand the effect of the thickness of surface layer, the diameter and length of the improvement body on the reinforcement effect of geogrid. The result showed that the effect of the surface layer thickness is greater than the effect of the deep layer diameter. Moreover, when the surface layer is reinforced with a geogrid, the strength of the surface layer part is enhanced and this effect of a geogrid reinforcement caused the reduction of surface settlement.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.67-78
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• 2010

Surface sedimentary facies and the change of microphytobenthos distribution in Geunso Bay tidal flat were monitored using remotely sensed data. Sediment distribution was analyzed along with the spectral reflectance based on the in situ data, and the spectral characteristics of the area where microphytobenthos occupied was examined. A medium to low spatial resolution of satellite image was not suitable for the detection of the surface sediments changes in the study area due to its ambiguity in the sedimentary facies boundary, but the seasonal changes of microphytobenthos distribution could be obviously detected. However, area of predominance of sand grains and seagrass distribution could be distinctly identified from a high spatial resolution remote sensing image. From this, it is expected that KOMPSAT-2 satellite images can be applied effectively to the study on the surface sedimentary facies and detailed ecological mapping in a tidal flat.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.27-33
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• 2007

Heavy metals in the surface seawaters and sediments were measured in Jinhae Bay. The high concentrations of heavy metals in the seawaters were found at the stations near the islands. In the sea waters, the mean concentrations of dissolved heavy metals except for Pb were not higher than previous data in this bay. Higher heavy metal contents in the surface sediments were observed at the stations adjacent to the Kojedo or Kadukdo of the Kadoksudo. The contents of Co, Ni, Zn, Cu, As and Cd in the surface sediments showed relatively high correlation coefficients with IL and COD. The order of enrichment factors(EFs) of heavy metals in the sediments was As>Cd>Pb>Zn>Co>Cu>Hg>Ni, and the EFs of As, Cd, Pb and Zn were higher than 1.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.683-691
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• 2001

This study aimed to clarify the influencing factors of the mesopore ratio on a pore geometry of surface soil in mixed stands as an index of the water retention capacity. Twenty four factors including site conditions and soil properties were analyzed by spss/pc+ for the data collected from during March to October of 1995. The factors influencing the mesopore ratio(pF2.7) on the surface soil were as follows; mesopore ratio(pF2.7) on the B horizon soil, under vegetation coverage, organic matter contents of surface soil and F layer depth. And influencing factor on the ratio of mesopore in the soil surface was correlated with surface soil hardness and depth of 10cm soil hardness shows high negative significance. Also, multiple regression equations for mesopore ratio of the mesopore ratio of B horizon soil and organic matter contents shows high significance($R^2$; 0.84).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.225-242
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• 2012

This is the first attempt to produce simultaneous surface current field from satellite altimeter data for the entire East Sea and to provide surface current information to users with formal description. It is possible to estimate surface geostrophic current field in near real-time because satellite altimeters and coastal tide gauges supply sea level data for the whole East Sea. Strength and location of the major currents and meso-scale eddies can be identified from the estimated surface geostrophic current field. The mean locations of major surface currents were explicated relative to topographic, ocean-surface and undersea features with schematic representation of surface circulation. In order to demonstrate the practical use of this surface current information, exemplary descriptions of annual, seasonal and monthly mean surface geostrophic current distributions were presented. In order to objectively classify surface circulation patterns in the East Sea, empirical orthogonal function (EOF) analysis was performed on the estimated 16-year (1993-2008) surface current data. The first mode was associated with intensification or weakening of the East Korea Warm Current (EKWC) flowing northward along the east coast of Korea and of the anti-cyclonic circulation southwest of Yamato Basin. The second mode was associated with meandering paths of the EKWC in the southern East Sea with wavelength of 300 km. The first and second modes had inter-annual variations. The East Sea surface circulation was classified as inertial boundary current pattern, Tsushima Warm Current pattern, meandering pattern, and Offshore Branch pattern by the time coefficient of the first two EOF modes.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.401-410
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• 2005

The purpose of this study was to assess the effect of heat therapy on cutaneous blood flow and skin temperature at pre-auricular region. Moist heat therapy and ultrasound therapy were applied to 20 healthy subjects(male: 10, female: 10). Cutaneous blood flow and skin temperature before and after heat therapy were measured with laser doppler flowmetry and thermocouple. The results were as follows ; 1. Cutaneous blood flow and skin temperature were significantly increased after moist heat therapy and ultrasound therapy. 2. In application of moist heat therapy, cutaneous blood flow and skin temperature were more increased and maintained longer than in ultrasound therapy. 3. Before heat therapy, cutaneous blood flow and skin temperature were higher in male. 4. There was no significant gender difference in changes of cutaneous blood flow and skin temperature after heat therapy. In conclusion, both moist heat therapy and ultrasound therapy increased cutaneous blood flow and skin temperature significantly, and moist heat therapy was more effective to increase cutaneous blood flow and skin temperature and to maintain increased cutaneous blood flow and skin temperature. There was no significant gender difference in the effect of heat therapy on cutaneous blood flow and skin temperature.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.412-421
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• 2010

As a most conservative, minimally invasive trial against early caries lesions, resin infiltration concept has been introduced and studied mainly about effective materials and pre-treatment methods of surface layers to arrest the lesion effectively, which is still going on. This study was performed with an aim of evaluating the efficacy of arresting the caries process in the natural incipient lesions in spite of removing the surface layers and we obtained the results as follows: 1. It was revealed that infiltration groups(1, 3, 5) showed lower radio-density decline between pre- and posttreatment than control groups(2, 4, 6)(p<0.05). 2. Group 5, in which the surface layer was removed with hydrochloric acid, showed the most significant anticariogenic effect(p<0.05). 3. Under SEM evaluation after infiltration, group 1 and 3 showed more irregular destruction and intensive loss of surface layers than group 5. In conclusion, it was thought resin infiltration can be an effective tool against the early caries lesions although surface layers are removed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.2
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• pp.59-64
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• 2003

The long­term trend and inter­relationship with depth of temperature and salinity in coastal waters of Korea are studied using coastal oceanographic observation and serial oceanographic data measured by National Fisheries Research and Development Institute. Temperature of coastal waters of Korea except south­western sea of Korea where cold water appears to increase in summer. In case of temperature offshore, surface temperature of East Sea increases, the reverse, for 50m and 100m decreases. Temperature in South Sea of Korea increases in whole depth and for the Yellow Sea, surface temperature increases, but for 50m decreases. In case of salinity offshore, surface salinity of East Sea decreases, but for 50m increases. Surface salinity in South Sea of Korea decreases, the reverse, form 50m and 100m increases. salinity in the Yellow Sea decrease in whole depth According to the result of inter­relationship analysis, for temperature relationship coefficients of 50m and 100m in the East Sea and South Sea of Korea is higher, however, for the Yellow sea the inter­relationship between 50m and 100m is lower. In case of salinity, the inter­relationship between surface and 50m, and for the South Sea of Korea, between 50m and 100m, and for the Yellow Sea, between surface and 50m is higher.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.49-59
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• 2013

Heavy rainfall intensity may cause shallow slope failures and debris flow by rill erosion and scour on land surface. The paper represents the difference between native soil (weathered soil) and reinforced soil, which is mixed by hardening agent with flyash as main material, for investigating experimental findings of rill erosion and erosion. Results obtained from artificial rainfall simulator show that erosion rate of reinforced soil mixed with hardening agent is reduced by 20% because an amount of eroded soil on slope surface is inversely proportional to the increase of soil strength. For example, rainfall of 45mm (at the elapsed time of 25mins in rainfall intensity of 110mm/hr) triggers rill erosion on native soil surface, but the rill erosion on reinforced soil surface does not even occur at 330mm rainfall (at the elapsed time of 3hrs in rainfall intensity of 110mm/hr). As a result of slope stability analysis, it was found that the construction method for reinforced soil surface would be more economical, easy and fast construction technology than conventional reinforcement method.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.314-323
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• 2001

This study aimed to clarify the influencing factors of mesopore ratio on a pore geometry of surface soil in coniferous stands as an index of the water retention capacity. Twenty three factors including site conditions and soil properties were analyzed by spss/pc + for the data collected during March to October of 1993. The factors influencing the mesopore ratio(pF2.7) on the surface soil were as follows; macropore ratio(pF1.6), slope, crown-cover rates, thickness of F layer, organic matter contents, and the growing stock. And influencing factor on the ratio of mesopore in the soil surface was correlated with percentage of amount of clay, soil surface, A and B horizon soil hardness shows high negative significance. Also, multiple regression equations for mesopore ratios of surface soil and surface soil hardness, clear length, growing stock, B horizon of soil hardness, organic matter contents show high significance($R^2$; 0.80). In coniferous stands, it is effective in promoting development on the ratio of mesopore that forest practice for enhancing of the water resource retention capacity should be carried out when the crown-cover rates of stands are more than 80 percentages.