• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_2
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• pp.529-538
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• 2013

Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

• Journal of the Korean GEO-environmental Society
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• v.14 no.2
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• pp.31-41
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• 2013

The dredged soils of western sea of Korea have been used as the fill materials because it possess the characteristics that constitute silt, silty sand and sand mainly. However, a study on dredged soils as the fill materials is insufficient. Hence, in this present study, the application the dredged soils of western sea of Korea as the fill materials was confirmed. Primary, the composition characteristics of the ground was analyzed to confirm the application on dredged soils as the fill materials by the piezo-cone penetration test. In laboratory test, it was performed the self-weight consolidation test for mechanical characteristics of the dredged soils. The direct shear test using self-weight consolidation test sample for shear strength characteristics was performed after self-weight consolidation test. Additionally, the mechanical characteristics of the dredged soils on elapsed time using self-weight consolidation test sample, which is drained naturally, was evaluated. The dredged soils of western sea of Korea show that unit weight and shear strength is increased as natural drain time elapses.

• Journal of Aquaculture
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• v.16 no.1
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• pp.44-50
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• 2003

This study aimed to develop the methods of growing Enteromorpha prolifera natural seedlings in its natural habitat and artificial indoor seedlings by inducing spore release. Likewise, the study examined the possibility of mass production by developing cultivation techniques with cultivating examination. The natural seedling of E.prolifera thrived in a sea area composed of sand and mud, which Is its natural habitat. Growing of this alga on the seedling frame 20 cm high from the bottom at the intertidal zone in summer and 40 cm high in fall was found to be very effective. However, enabling the best attachment rate for artificial indoor seedling requires inducing spore release after drying the mature thalli in a dark place fur about 12∼24 hours and setting seedling nets in a dark water tank (spore solution) for 24 hours. Breeding E.prolifera in a pole-system farm is best done in shallow sea areas with mud or mud and sand geological feature. However, floating-system lam is better for deep-sea areas with fast current. Ideal farming places are sea areas with plenty of nutritional salt and safe places that protect the lam facilities against billows. Furthermore, an exposure method on seawater surface to produce larger output should be used.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.11-11
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• 2016

Penicillium species are commonly isolated from various outdoor and indoor environments, including marine environments such as sponges, algae and sand. Penicillium is especially important because numerous bioactive compounds have been isolated. Penicillium was the most common species in intertidal zone in Korea, however the diversity and ecological roles of Penicillium in intertidal zone are not clarified. We explored diversity and ecological roles of marine-derived Penicillium from tidal flat and sea sand in Korea. The diversity of marine-derived Penicillium from Korea was investigated using both culture-dependent and culture-independent approach by ${\beta}$-tubulin sequence. In addition, we evaluated optimal temperature, halo-tolerance, and enzyme activity of Penicillium strains, such as extracellular alginase, endoglucanase, ${\beta}$-glucosidase, and protease. For culture-dependent approach, a total of 182 strains of 62 Penicillium species were isolated, with 53 species being identified. The most common species was Penicillium oxalicum, followed by P. crustosum, P. brasilianum, P. koreense, and P. griseofulvum. Species richness and composition were not significantly different by season, substrates, and seaside. For culture-independent approach using Illumina sequencing, 73 OTUSs were detected. The most frequently observed species was P. antarcticum, followed by P. koreense, P. crustosum, and P. brevicompactum. Diversity of Penicillium was higher during winter season than during summer season and in western sea than in southern sea, respectively. Community structure was significantly different by season and sea side. 52 species were detected by both methods. Unique species were isolated from each of methods - 10 from culture methods and 21 from Illumina sequencing. Furthermore, salinity adaption of the Penicillium varied depending on species. Many Penicillium species showed endoglucanase, ${\beta}$-glucosidase, and protease activity. Some species including P. paneum and P. javanicum degraded the polycyclic aromatic hydrocarbons. Thus, our results demonstrate that intertidal zone in Korea harbors diverse Penicillium community and marine-derived Penicillium play important ecological roles as decomposers of organic material in marine environments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.1 no.2
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• pp.59-72
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• 1996

The stratigraphy of the Gomso-Bay tidal flat consists of basement, preHolocene oxidized unit, and Holocene tidal sequence in ascending order. The oxidized unit is a yellowish brown stiff mud of the last stadial (or subglacial) stage before 12,000 yr B.P. This yellowish brown preHolocene unit does not contain any marine fossils, but contains plant roots, plant fragments, and also vertical and horizontal microfractures indicating soil-formation when exposed. It is regarded as interfluve deposits. The Holocene tidal sequence is composed of lower mud facies (upper-flat muds), upper sand and muddy sand facies (middle to lower-flat sands). This coarsening-upward and retrograding pattern of Holocene tidal deposits reflects a Holocene sea-level rise. The plots of $\^$14/C-age versus depth of dated samples (peats and shells) show that the sea level of 7,000 yr B.P. was located about 6.5 m below the present mean sea level, and the sea levels of 4,000 yr B.P. and 2,000 yr B.P. were also situated about 3 m and 2.5 m below the present mean sea level, respectively.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.409-414
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• 1998

To examine the detectability of the aerosol and/or Yellow dust from China crossing over the Yellow sea, three works carried out as follows , Firstly, a comparison was made of the visible(VIS), water vapor(WV), and Infrared(IR) images of the GMS-5 and NOAA/AVHRR on the cases of yellow sand event over Korea. Secondly, the spectral radiance and reflectance(%) was observed during the yellow sand phenomena on April, 1998 in Seoul using the GER-2600 spectroradiometer, which observed the reflected radiance from 350 to 2500 nm in the atmosphere. We selected the optimum wavelength for detecting of the yellow sand from this observation, considering the effects of atmospheric absorption. Finally, the atmospheric radiance emerging from the LOWTRAN-7 radiative transfer model was simulated with and without yellow sand, where we used the estimated aerosol column optical depth ($\tau$ 673 nm) in the Meteorological Research Institute and the d'Almeida's statistical atmospheric aerosol radiative characteristics. The image analysis showed that it was very difficult to detect the yellow sand region only by the image processing because the albedo characteristics of the sand vary irregularly according to the density, size, components and depth of the yellow sand clouds. We found that the 670-680 nm band was useful to simulate aerosol characteristics considering the absorption band from the radiance observation. We are now processing the simulation of atmospheric radiance distribution in the range of 400-900 nm. The purpose of this study is to present the preliminary results of the aerosol and/or Yellow dust detectability using the Ocean Scanning Multispectral Imager(OSMI), which will be mounted on KOMPSAT-1 as the ocean color monitoring sensor with the range of 400-900 nm wavelength.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.9-13
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• 1998

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.233-233
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• 2017

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.52-60
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• 2015

The objective of this research lies in the effect of installation parameters influencing on the wind proof performance of the coastal forest for damage prevention. The dissipation ratio of incident wind power is developed as an assessment index to make a lumped parameter study possible. From the real field data of East, West, and South Sea bounded on the Korean peninsula, single and double storied forests were modeled in three-dimensional shape with computer aided design, and so was done the artificial structures such as wind break, sand accumulating fence, and sand dune, etc With a commercial code ANSYS-CFX, the computational result from the comparison of dissipation ratio between single and double storied forest shows the effect of composition, and also the installation effect is investigated for artificial structures with optimal dimension of distance.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.73-77
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• 2006

Drying Shrinkage has much complexity as it has relations with both internal elements of concrete and external factors. Therefore, experiments on Concrete Drying Shrinkage are carried out in this study under simplified circumstances applying temperature & Humidity test chamber which enables constant temperature and humidify. Comparative analyses have been made respectively according to the consequences aiming at modelling for prediction of Concrete Drying Shrinkage and making out measures to reduce it. As a result Strain Rate of Drying Shrinkage of concrete was measured to increase by average $10{\times}10^{-5}$ in proportion to additional 4% increase in fine aggregate ratio, when water/cement ratio constant. Strain Rate of Drying Shrinkage in pit sand concrete increased 20% higher than measured when in river sand under the condition of 90-day material age. 6. Strain Rate of Drying Shrinkage in sea sand concrete increased $10%{\sim}15%$ higher than measured when in river sand. The results of prediction of Rate of Drying Shrinkage by Response Surface Analysis are as fellows. The coefficient of correlation of Drying Shrinkage in concrete was over 90%.