• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.168-176
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• 2010

Stability and durability of the artificial reefs (ARs) for wildstock enhancement have been a key issue. We surveyed the side scan sonar (SSS), multi beam echo sounder (MBES) and scuba diving surveys confirmed that the ARs stability was age and type-dependent. A case of the stability of 8,438 ARs (60 group ARs) installed at 4 sites (Yangyang, Gangeung, Donghae and Samcheok) along the Gangwon coast of the East Sea (Sea of Japan). And a confirmation amount to 85.4% ARs remained safe, the rest 14.6% being influenced by a physical parameter of the waters. The representative influences by their circumstances were of breakage (6.3%). capsizing (8.3%). A group of a ARs to 61.7% ARs remained safe, the rest 38.3% being influenced by a physical parameter of the waters. The representative influences by their circumstances were of buried.

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.91-97
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• 2011

This study examines the morphological features of larval and postlarval shells of the paedomorphic bivalve Crenella decussata Montagu, 1808 from the Sea of Japan. During the early morphogenesis of the shell of C. decussata the following characteristics appear: prodissoconch I -the anterior and posterior provincular teeth, a broad primary ligament pit located on the chondrophore; nepioconch - the anterior and posterior juvenile teeth,primary lateral teeth, fine commarginal and radial sculpture. Larvae of C. decussata distinctly differ from other mytilid larvae by a D-shaped shell, absence of umbo, astraight hinge margin, and homogeneous fine-grained sculpture without co-marginal lines of growth. These shell characters indicate lecithotrophic development of this species. Some morphostructures are revealed which might be used in crenellin taxonomy.

• 한국해양학회지
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• v.25 no.1
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• pp.36-48
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• 1990

This study was carried out to obtain some informations on the species composition and distribution pattern of Polychate community on the continental shelf and slope area in the East Sea. Fauna samples were collected from three sampling cruises in April of 1985, and April and October of 1987. Total 112 polychaete taxa included in 36 families were collected. Dominant species in the study area were Chaetozone setosa, Aglaophamus malmgreni, Ampharete arctica Terebellides horikoshii, Tharyx sp., and Magelona pacifica. Northern and cold water species were major contributors of polychaete communities in this study area. Dominant species showed their specific depth ranges from shelf area to upper slope and middle slope depth. The overall density was 300 indiv./m$\^$2/ and species richness was around 12 species/0.2m$\^$2/. Significant changes in mean polychaete density and species richness along depth gradient were found approximately at 600 m or deeper depth. Among physical factors, water depth, temperature and clay content, mean grain size were significantly correlated with the mean density of dominant species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.202-209
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• 2000

In order to estimate demersal fishes using acoustic echo sounders and echo integrators, we consider several problems that are accurate bottom detection, optimum bottom offset and dead zone. The dead zone where no fish detection are summed distance resolution by the half pulse length of transmitted pulse and beam angle above the seabed. This paper has considered the dead-zone correction method to be technically correct for survey of demersal fishes. A comparison between near-bottom SV profiles acquired in Funka Bay, Hokkaido, of Japan, the East China Sea and the Yellow Sea, of Korea, with before and after the bottom correction, shows that the SV obtained with after the bottom correction is 2∼3dB higher than before the bottom correction in Funka Bay, and 17dB higher in East China Sea, too.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.28-28
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• 1995

The aim of the present study is to investigate the interannual variabilities of the East Asia monsoon rainfall associated with the global sea surface temperature anomaly(SSTA). For this study, the summer rainfall(from June to August) over the twenty-eight period of 1961-1988 were analyzed with being divided by nine-subregions over East Asia including Korea, China and Japan. From the analysis of the principal modes explaining the interannual variation, the interannual variabilities of summer rainfalls in South Japan and Korea are larger than those of the other subregions of the East Asia. There is a strong negative correlation between the summer rainfalls of south China and Korea. In this study, the relationship between the summer monsoon of each subregion and SSTs of the tropical NINO regions, of western Pacific warm pool, and of the subtropical ocean were investigated. The longitudinal sections of the lagged cross correlations of the summer rainfal1 anomaly in (a) Korea and (b) south China, and the monthly SSTA in the equatorial(averaged from 65 to 6N) Pacific were analyzed. The negative maximum correlation pattems of Korea''s stammer rainfal1 and SSTs over the eastern Pacific is transfered to positive maximum conrlation over central Pacific region with a biennial periodicity. In South China, the significant positive correlations are found at -12 month lag over the eastern Pacific and maximum negative correlation at 16 month lag over the central Pacific with the quasi-biennial oscillation. But the correlation coefficient reverses completely to that in Korea. In order to investigate the most prevailing interannual variability of rainfall related to the favored SSTA region, the lagged cross correlations between East Asia rainfall and SSTs over the moO regions(NINO 1+2(0-105, 90W-80W), NINO 3(5N-5S, 150W-90W), NINO 4(5N-5S, 160E-l50W) and the western Pacific worm pool (5N-5S, 120E-l60E) were analyzed. Among the lagged cross-correlation cycles in NINO regions, the maximum correlations for the negative lagged months prevail in NINO 1+2 and NINO 3, and the cross correlations for the positive lagged months NINO 4. It is noteworthy that correlation between the western Pacific warm pool SSTA and the monsoon rainfall in Korea and South China have the maximum value at negative 4 month lag. The evolution of the correlation between the East Asia monsoon rainfall and SSTA is linked to the equatorial convective cluster and related to northward propagating situation, and raising the possibility that the East Asia monsoon precipitation may be more fundamentally related to the interaction of intraseasonal oscillations and the sub-regional characteristics including the surface boundary conditions and the behavior of climatological air mass.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.413-426
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• 1995

The aim of the present study is to investigate the interannual variabilities of the East Asia monsoon rainfall associated with the global sea surface temperature anomaly(SSTA). For this study, the summer rainfall(from June to August) over the twenty-eight period of 1961-1988 were analyzed with being divided by nine-subregions over East Asia including Korea, China and Japan. From the analysis of the principal modes explaining the interannual variation, the interannual variabilities of summer rainfalls in South Japan and Korea are larger than those of the other subregions of the East Asia. There is a strong negative correlation between the summer rainfalls of south China and Korea. In this study, the relationship between the summer monsoon of each subregion and SSTs of the tropical NINO regions, of western Pacific warm pool, and of the subtropical ocean were investigated. The longitudinal sections of the lagged cross correlations of the summer rainfal1 anomaly in (a) Korea and (b) south China, and the monthly SSTA in the equatorial(averaged from 65 to 6N) Pacific were analyzed. The negative maximum correlation pattems of Korea's stammer rainfal1 and SSTs over the eastern Pacific is transfered to positive maximum conrlation over central Pacific region with a biennial periodicity. In South China, the significant positive correlations are found at -12 month lag over the eastern Pacific and maximum negative correlation at 16 month lag over the central Pacific with the quasi-biennial oscillation. But the correlation coefficient reverses completely to that in Korea. In order to investigate the most prevailing interannual variability of rainfall related to the favored SSTA region, the lagged cross correlations between East Asia rainfall and SSTs over the moO regions(NINO 1+2(0-105, 90W-80W), NINO 3(5N-5S, 150W-90W), NINO 4(5N-5S, 160E-l50W) and the western Pacific worm pool (5N-5S, 120E-l60E) were analyzed. Among the lagged cross-correlation cycles in NINO regions, the maximum correlations for the negative lagged months prevail in NINO 1+2 and NINO 3, and the cross correlations for the positive lagged months NINO 4. It is noteworthy that correlation between the western Pacific warm pool SSTA and the monsoon rainfall in Korea and South China have the maximum value at negative 4 month lag. The evolution of the correlation between the East Asia monsoon rainfall and SSTA is linked to the equatorial convective cluster and related to northward propagating situation, and raising the possibility that the East Asia monsoon precipitation may be more fundamentally related to the interaction of intraseasonal oscillations and the sub-regional characteristics including the surface boundary conditions and the behavior of climatological air mass.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.345-356
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• 1995

Examining the precipitation data collected during the period from 1960 to 1993, we found that Taegu Station represents an optimum station for explaining the interannual variations of the precipitation in Korea. Using the variations derived from Taegu, the secular trends of the precipitation in Korea have been studied. It was 삽so found that the interannual variations of summer monsoon precipitation are consistent with those of the annual precipitation. To explore the interannual variations of the summer monsoon precipitation, comparisons of the summer precipitation in Korea with that in China and Japan were made. The results of the empirical orthogonal function analysis showed that Korea, the Yangtze River and Huaihe River valley, and the south Japan are all located in the same climate system during summer. The detailed analysis was carried out on the comparison of the summer precipitation in Korea with that in the eastern part of the the mainland China. We found that the correlation pattern is similar to the East Asia/pacific pattern. The probable effects of the sea surface temperature on the precipitation in Korea were also discussed. Key Words : Precipitation in Korea, rainy seasons in East Asia, monsoon precipitation, interannual variations.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.6
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• pp.265-271
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• 2015

The tsunami hazard analysis is performed for testing the application of probabilistic tsunami hazard analysis to nuclear power plant sites in the Korean Peninsula. Tsunami hazard analysis is based on the seismic hazard analysis. Probabilistic method is adopted for considering the uncertainties caused by insufficient information of tsunamigenic fault sources. Logic tree approach is used. Uljin nuclear power plant (NPP) site is selected for this study. The tsunamigenic fault sources in the western part of Japan (East Sea) are used for this study because those are well known fault sources in the East Sea and had several records of tsunami hazards. We have performed numerical simulations of tsunami propagation for those fault sources in the previous study. Therefore we use the wave parameters obtained from the previous study. We follow the method of probabilistic tsunami hazard analysis (PTHA) suggested by the atomic energy society of Japan (AESJ). Annual exceedance probabilities for wave height level are calculated for the site by using the information about the recurrence interval, the magnitude range, the wave parameters, the truncation of lognormal distribution of wave height, and the deviation based on the difference between simulation and record. Effects of each parameters on tsunami hazard are tested by the sensitivity analysis, which shows that the recurrence interval and the deviation dominantly affects the annual exceedance probability and the wave heigh level, respectively.

• Acta Via Serica
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• v.8 no.2
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• pp.125-154
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• 2023

Historically, commerce was a significant factor in the proliferation and development of Buddhism, which is especially manifest in the cult of the bodhisattva Avalokiteśvara. Iconographic and textual evidence testifies that maritime trade on the Indian Ocean played a fundamental role in the formation of Avalokiteśvara worship. The sea was also a major conduit through which elements of the Avalokiteśvara faith were transmitted from India through China to Korea and Japan, the easternmost ends of the Silk Road. These elements include Avalokiteśvara's role as a maritime savior, oceanic symbolism, and the concept of the bodhisattva's worldly abode, Potalaka. Cultic sites dedicated to maritime safety were established at important transport hubs in East Asia. Due to China's strategic location on the Silk Road, as well as its cultural influence, the most important cultic sites were founded in China, first on the Shandong Peninsula, then in the southern Jiangnan region, in present-day Zhejiang Province. Especially notable is the role that Korean seafarers played in this process by assisting monks in search of the Dharma, establishing temples, and transmitting religious beliefs across the ocean. The present study focuses on the role that maritime figures played in the cultural exchanges between Korea, China, and Japan examined through Avalokiteśvara faith. By this, it aims to demonstrate how Korean seafarers inherited and continued the traditional relationship between commerce and Buddhism, while extending the Maritime Silk Road to the "East Asian Mediterranean."

• The Journal of Humanities and Social Sciences (IHSS)
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• v.20 no.4
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• pp.1-25
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• 2019

The North Korean Route connecting Japan and Manchuria(滿洲) in the modern era was based on three ports, which were Chungjin(淸津), Najin(羅津) and Unggi(雄基). Strengthening the logistics network capabilities of the three ports of North Korea and establishment of the integrated railway network of the continent were not only economic but also military strategic decision. In 1932, Najin was designated as the shortest distance transit port connecting Manchuria and Japan under the influence of the Japanese military. Najin Port became the base for military transportation, transportation of Manchurian immigrants and transportation of Manchurian resources and Japanese products. The Japanese Government General of Korea planned to construct Najin Port as a port with a capability to load and unload 9 million tons annually by 1948. At the same time, the Japanese military designated Najin and Unggi as fortresses and managed them as military zones, and established Najin Fort Command Post in 1935 to begin constructing a fort. In the 1930s, the Korean East Sea traffic network was operated and strengthened by the military factor through this process.