• Journal of Industrial Technology
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• v.25 no.A
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• pp.57-65
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• 2005

In this paper, for the highly plastic marine soft clay distributed in west and southern coast of Korean peninsula of Kwangyang and Busan New Port areas, correlation between compression index and other indices representing geotechnical engineering properties such as liquid limit, void ratio and natural water content were analyzed. Appropriate empirical equations of being able to estimate the compressibility of clays in the specific areas were proposed and compared with other existing empirical ones. For analyses of the data and test results, data for marine clays were used from areas of the South Container Port of the Busan New Port, East Breakwater, Passenger Quay, Jungma Reclamation and Reclamation Containment in the 3rd stage in Kwangyang. In order to find the best regression model by using the commercially available software, MS EXCEL 2000, results obtained from the simple linear regression analysis, using the values of liquid limit, initial void ratio and natural water content as independent variables, were compared with the existing empirical equations. Multiple linear regression was also performed to find the best fit regression curves for compression index and other soil properties by combining those independent variables. On the other hands, another software of SPSS for non-linear regression was used to analyze the correlations between compression index and other soil properties.

• The Korean Journal of Zoology
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• v.5 no.2
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• pp.13-17
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• 1962

The author colelcted crabs (Tribe Brachyura ) on the coasts of fourteen western islands of South Korea (Paenyong Do, Taechong Do, Sochong Do, Taeyonpyong Do, Kanghwa Do, Yongjong Do, Chagyak Do, Tokchok To. Moktok To. Pukkyoknyolbi Do. Ong Do, ANmyon Do, Pigum Do, and Taehuksan Do) mainly in summers during a period ranging from 1955 to 1962. Of these Islands, Paeknyong , Taehong, Taeyonpyong, Ong, Anmyon, Pigum and Taehuksan Do are the localities where the crabs were investigated firstly by the present author. The collections made by the author consist of 1779 specimens of crabs involving 9 families. 25 genera, 33 species and 5 subspecies (Table2). 23 species of crabs had been reported hitherto from Tokchok To and 7 from Kanghwa Do. In present paper the author adds 1 species to the fauna of crabs of Tokchok To and 7 to that of Kanghwa Do. In present paper the author adds 1 species to the fauna of crabs of Tokchok To and 7 to that of Kanghwa D. Among 38 species or subspecies of crabs collected, Oregonia gracilis, Cancer amphioetus and Chaesmagnathus convexus are new to the fauna of the west coast of Korea. 57 species of crabs are therefore identified in this area. The author collected Pinnotheres cardii on Taechong Do and Scopimera bitympana on Pigum Do. It became, therefore, clear that these two kinds of crabs occur much wider areas than known hitherto in Korea. The nothern limit of the distribution of Ocypoda stinpsoni and Sesarma haematocheir is Kyungki Bay as known already, that of Helice tridens is ,however, more northern part than Kyungki Bay, since they were collected on Paeknyong Do.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.211-233
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• 2006

The purpose of this study is to analyze traffic volume between the Korean container ports located at the west coast and northern Chinese ports and then the distribution trend of container between Korea and China. The findings of the study are as follows. First, Container traffic between western Korean ports and northern Chinese ports has been increasing due to an increasing trade volume between both countries and geographical accessibility. Second, Seoul and neighboring area tend to use the trade route between the western ports and northern Chinese because of lower logistics costs and time-saved advantage compared to another ports. Third, the growth of the western ports did depend mainly on the northern China oriented growth. Such a fact could leads to the overlapping investment in port development in Korea and another intense competition among national ports to attract cargoes and liners. Therefore, port development policy considering the characteristics and function of national ports have to be established. and also alternatives and strategies for improving the competitive edge of small and medium sized shipping lines against the opening of shipping market have to be worked out.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.265-265
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• 2021

해수면 상승과 연안지역의 무분별한 지하수의 이용으로 해수침투는 가속화되고 있다. 해수면 상승과 지하수의 과잉 양수로 인한 연안지역의 대수층은 사용 가능한 담수 지하수자원이 줄어들고 있다. 연안지역의 대수층을 대상으로 해수 침투 영역에 미치는 영향에 대한 연구는 활발하게 진행되고 있다. GALDIT은 index & ranking 방법을 이용한 지하수자원의 해수침투에 대한 취약성 평가 방법으로 Geographic Information System (GIS)을 통해 주제도에 대한 중첩으로 평가 지수를 산정한다. 한국의 해수침투 취약성 평가에 대한 선행 연구 중 상당수는 제주도를 대상으로 많은 연구가 수행되었으며, GALDIT을 이용하여 해수침투에 대한 취약성 평가가 수행되었다. 본 연구에서는 내륙의 연안지역을 대상으로 GALDIT을 적용하였다. 한국의 서해안 지역 중 도심지가 밀집되어 있는 북쪽으로 선택하였다. 연구지역은 인천, 아산, 안산, 김포, 화성, 시흥, 평택, 당진, 오산으로 9개의 행정구역으로 구성되어 있다. 9개의 지역은 모두 제조업이 발달되어 도시화가 가속화되고 있으며, 지속적인 인구의 유입이 진행되고 있다. GALDIT은 지속가능한 해안지하수를 위한 수자원 계획을 뒷받침하는 평가 자료로 사용될 수 있으며, 국내 기후 및 공간 특성 매개변수를 고려한 가중치 및 평가 기준의 확대 등이 필요할 것으로 생각된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.695-706
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• 1998

SST (Sea Surface. Temperature) fronts which were found in the South-West Sea of Korea and the northern area of the East China Sea were examined in order to clarify their positions, shapes, seasonal changes and the formation mechanism, For this study used SST data rearranged from the SST IR image during 1991 to 1996 and oceanographical data obtained by National Fisheries Research and Development Institute. Temperature front in the Cheju Strait was analyzed by the data obtained from a fisheries guidance ship of Cheju Provincial Government, The coastal frontal zone in the South-West Sea of Korea and the offshore frontal zone in the northern area of the East China Sea can be divided into several types (Type of Winter, Summer, Spring, Autumn and late Autumn), Short term variations of SST fronts have a tendency not to move to any Bleat extent for several days. The location of the frontal zone in the southwestern sea of Cheju Island changes on a much large scale than that of the one in the southern coast of Korea, The frontal Tone, formed every year in the southern sea of Korea approaches closer to the coastal area in winter, and moves closer to the south in spring and autumn. The frontal zone of the southwestern sea of Cheju Island moves in a westerly direction from the east, and reaches its most westerly point in the winter and its most easterly point in the summer related to the seasonal change of the Tsushima Current. Additionally, the frontal zone of the southwestern sea of Korea becomes extremely weak in March, April and November. SST fronts are formed every year around the line connecting Cheju Island to Yeoseo Island or to Chungsan Island in the Cheju Strait. A Ring-shaped tidal mixing front appears along the coastal area of Cheju Island throughout the year except during the months from November to January. Especially, in May and October fronts are formed between the coastal waters of Cheju Island and the Tsushima currents connecting the frontal zone of the coastal region in the southern sea of Korea with that of the southwestern sea of Cheju Island.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.02a
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• pp.32-41
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• 2000

Sand drain as a vertical drainage is widely used in soft ground improvement Recently, sand, the principal source of sand drain, is running out. The laboratory model tests were carried out to utilize gravel as a substitute for sand. Though which the characteristics of gravel are compared to those of sand for engineering purpose. Two cylindrical containers for the model test were filled with marine clayey soil from the west coast of Korea with a column in the center, one with sand, the other with gravel. Vibrating wire type piezometers were installed at the distance of 1.0D, 1.5D and 2.0D from the center of the column. The characteristics of consolidation were studied with data obtained from the measuring instrument place on the surface of the container. The parameter study was performed on the marine clayey soil before and after the test in order to verify the effectiveness of the improvement. The clogging effect was checked at various depth in gravel column after the test. In-situ tests area was divided into two areas by material used. One is Sand Drain(SD) and Sand Compaction Pile(SCP) area, the other is Gravel Drain(GD) and Gravel Compaction Pile(GCP) area. Both areas were monitored to obtain the information on settlement, pore water pressure and bearing capacity by measuring instruments for stage loading caused by embankment. The results of measurements were analyzed. According to the test results, the settlement was found to be smaller in gravel drain than in sand drain. The increase in bearing capacity by gravel pile explains the result. The clogging effect was not found in gravel column. It is assumed that gravel is relatively acceptable as a drainage material. Gravel is considered to be a better material than sand for bearing capacity, and it is found that bearing capacity is larger when gravel is used as a gravel compaction pile than as a gravel drain.

• 한국해양학회지
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• v.9 no.2
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• pp.19-30
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• 1974

Current observations were carried out in Jinhae Bay area during the period of January to February 1974. The data were synthetically analyzed and the characteristics of the water movement in Jinhae Bay were studied. The water movement in Jinhae Bay area is a reversing tidal current type and the Semi- diurnal tidal current is predominant. The ebb current begins at about high water time and the strongest current occurs at about 3 hour after high water. The flood current begins at 0.2-1.0 hour before low water and the strongest current occurs at about 3-4 hour after low water. The main ebb current flows to SE direction with the maximum welocity, about 100cm/sec and the lood flows to NW with the maximum velocity, about 70cm/sec. Generally, the ebb current in Jinhae Bay is more predominat than the flood current except at the west and the north coast area of Gadeog-do where the flood current is more predominant.

• Journal of the Korean earth science society
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• v.25 no.4
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• pp.277-288
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• 2004

In this study, state of sea surface were analyzed comparatively for cases of low atmospheric pressure, which occurred in the middle area of China and moved eastward to the Korean Peninsula across the Yellow sea during April 9-12, 1999, and typhoons 'NEIL' May 1999 and 'OLGA' July 1999, which moved northward along the west coast of the Korean Peninsula. In cases of low pressure, wind speeds and phases were respectively stronger and faster in the center area than in the surrounding areas. The wave heights seem to a somewhat differing tendency from that of the wind speeds due to the influences of geometry. On the other hand, wave heights were lower under typhoon weather than under low pressures, except the instance of wave height over 5 m on Chilbal when typhoon Olga pass northward from the southern area. Storm surges also showed larger amplitudes under low pressures than under typhoons. The results suggest that wave sand storm surges may be larger for a slow passing synoptic low pressures than for a fast passing local typhoon.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1363-1371
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• 2013

In this study, we estimate the interannual spatial and temporal distributions of fishing grounds at night in the East Sea based on satellite and in-situ data. We observe that the $15^{\circ}C$ thermal front moves in the north-south direction according to the movement of the warm water (above $18^{\circ}C$) in the Tsushima Warm Current (TWC) area, forcing the cold water area (below $10^{\circ}C$) to either expand or shrink. The interannual variations of sea surface temperature (SST) in winter represented by the indicator SST of $6^{\circ}C$ are consistent with the east-west zonal areas in the central East Sea which represented over $1^{\circ}C$ standard deviation of SST in February during 1990-2000. Annual SST in the fishing grounds of common squid fishing vessels, observed both by fishing vessels and satellites range from 9-$22^{\circ}C$, with the satellite-observed data having a larger range than the fishing vessel-based ones. The interannual distributions of the common squid fishing grounds in the East Sea are mostly concentrated in the TWC area in the southwestern part of the East Sea and in the coast of southern Honshu and Hokkaido in Japan. The interannual distributions of the nighttime fishing vessels are consistent with the catches investigated from the fishing vessel.

• 한국해양학회지
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• v.28 no.4
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• pp.259-271
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• 1993

The distributions of bottom sediments and the depositional processes on the continental shelves of Korean Seas are interpreted. Generally the continental shelf sediments can be classified into the sand-facies and mud-facies, showing the typical bimodal size distributions Most of the sandy and gravelly sediments on the outer shelf floor are interpreted as "relict" sediments that were deposited during the last glacial times when the sea level was lower than the present. On the other hand the muddy sediments on the inner shelf area are interpreted as "recent" sediments that are deposited under the present environment conditions. It is understood that most of the fine materials cannot escape the inner shelf area due to the strong tidal and coastal fronts, and are transported eastward from the West Sea along the southern coast of Korean Peninsula. The dark-colored muddy sediments in the Hupo Basin of the East Sea are, however, considered to be "relict" sediments. In the midshelf area fine materials are mixed with the relict coarse sediments, and some of the relict sediments are continuously reworked under the present environmental conditions forming the "palimpsest" sediments.