• Title/Summary/Keyword: Southern coast

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The Distributions of Copepods and Chaetognaths in the Southern Waters of Korea and Their Relationship to the Characteristics of Water Masses (한국 남해의 요각류 및 모악류의 분포와 수괴특성)

  • PARK Joo-Suck;LEE Sam-Seuk;KANG Young-Shil;LEE Byung-Don;Hun Sung-Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.3
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    • pp.245-252
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    • 1990
  • The distributions of copepods and chaetognaths in waters off the southern coast of Korea were investigated to evaluate their reliability as indicator species of different water masses. The samples for this study were collected vertically from about 5m above the bottom at 28 stations along 8 transects in three different months, February, April, and August, 1988. The sampling gear used was 0.45-meter NORPAC plankton net fitted with 0.33mm mesh. Acartia clausi, Centropages abdominalis, and Sagitta crassa were found to be reliable indicator species of neritic cold waters; Pleuromamma gracilis, Undinula darwini, Calocalanus plumulosus, Calanopia elliptica, and Sagitta enflata were of oceanic warm waters; Temora discaudata and Centropages furcatus were of neritic warm waters. According to the cluster analyses of the species found, the distinctive area in February was divisible into two regions or water masses, the coastal and off-shore regions; in April, however, it was divisible into four regions. In August, it was divisible into three areas, further indicating the strength of the Kuroshio tributaries pushing toward the coast.

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Study on the Annual Reproductive Cycle of the Comb Pen Shell, Atrina pectinata (Linnaeus, 1767) (Mollusca: Bivalvia: Pinnidae) on the Southern Coast of Ulleungdo Island, Korea (울릉도 남해역에 서식하는 키조개의 연중 번식주기에 관한 연구)

  • Yang, Hyun-Sung;Noh, Choong Hwan;Yoon, Sung Jin;Kim, Yun-Bae;Choi, Kwang-Sik;Kang, Do-Hyung
    • Ocean and Polar Research
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    • v.38 no.1
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    • pp.21-33
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    • 2016
  • Gametogenesis of the comb pen shell, Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) on the southern coast of Ulleungdo Island, Korea was assessed monthly (November 2013 to October 2014) using histology. Gametogenesis commenced in January when the surface water temperature was $12.6^{\circ}C$ and pen shells evidenced an early development phase with small oogonia from January to April, although few females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached $19.3^{\circ}C$ and July ($23.2^{\circ}C$) respectively. The spawning activity continued until the end of September. Histology indicated that the spawning peak of the females in Ulleungdo Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. The present study is the first provided fundamental information on the life history of A. pectinata in Ulleungdo Island, and this can be put to good use in the management of this pen shell in the study area.

Seasonal and Interannual Variation in Species Composition of Fish Assemblages Collected by Pots in the Southern Coast of East Sea, Korea (동해 남부 연안해역 통발에서 채집된 어류 군집의 계절변동과 연간변동)

  • Park, Joo Myun;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
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    • v.27 no.4
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    • pp.310-316
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    • 2015
  • The seasonal and interannual variation in the species composition and abundance of the fish assemblage were studied. Fish samples were collected seasonally over 4 year (2005 to 2008) using pots in the southern coast of East Sea. During the study period, a total of 32 fish species belonging to 24 families were collected. The dominant species were Conger myriaster, Paracentropogon rubripinnis, Liparis tanakae, Parapercis sexfasciata, Eptatretus burgeri and Clupea pallasii pallasii, which accounted for 91.9% of the total number of individuals collected. The number of species, number of individuals, biomass, and diversity fluctuated with season. The peak number of species and number of individuals occurred were in August 2008, whereas the biomass was the highest in August 2005 and diversity was in May 2008. The abundance of dominant species also showed some seasonal and interannual changes. A one-way analysis of similarity (ANOSIM) showed that the fish assemblage in 2008 was significantly different from those of 2005, 2006 and 2007, whereas there was no significant difference among seasons over 4 years.

The Recent Increase in the Heavy Rainfall Events in August over the Korean Peninsula

  • Cha, Eun-Jeong;Kimoto, Masahide;Lee, Eun-Jeong;Jhun, Jong-Ghap
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.585-597
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    • 2007
  • The characteristics of the rainfall events on the Korean peninsula have been investigated by means of regional and global observational data collected from 1954 to 2004 with an emphasis on extreme cases $80\;mm\;day^{-1}$. According to our analysis, long-term annual rainfall anomalies show an increasing trend. This trend is pronounced in the month of August, when both the amount of monthly rainfall and the frequency of extreme events increase significantly. Composite maps on August during the 8 wet years reveal warm SST anomalies over the eastern Philippine Sea which are associated with enhanced convection and vertical motion and intensified positive SLP over central Eurasia during August. The rainfall pattern suggests that the most significant increase in moisture supply over the southern parts of China and Korea in August is associated with positive SLP changes over Eurasia and negative SLP changes over the subtropical western Pacific off the east coast of south China. The frequent generation of typhoons over the warm eastern Philippine Sea and their tracks appear to influence the extreme rainfall events in Korea during the month of August. The typhoons in August mainly passed the western coast of Korea, resulting in the frequent occurrence of extreme rainfall events in this region. Furthermore, anomalous cyclonic circulations over the eastern Philippine Sea also promoted the generation of tropical cyclones. The position of pressure systems - positive SLP over Eurasia and negative SLP over the subtropical Pacific - in turn provided a pathway for typhoons. The moisture is then effectively transported further north toward Korea and east toward the southern parts of China during the extreme rainfall period.

Detection of Marine Birnavirus(MABV) from Marine Fish in the Southern Coast of Korea (남해안 자연산 어류에서 Marine birnavirus(MABV)의 검출)

  • Yun, Hyun-Mi;Kim, Seok-Ryel;Lee, Wol-La;Jung, Sung-Ju;Oh, Myung-Joo
    • Journal of Aquaculture
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    • v.21 no.1
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    • pp.13-18
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    • 2008
  • Marine birnavirus(MABV) are well known fish pathogens in Asian countries such as Korea, Japan, and China. Prevalence of viral disease, geological distribution and host or reservoir of viruses were investigated from wild marine fishes in southern coast of Korea in 2003 and 2005. RT-PCR results showed that MABV were detected in 17 fishes(10.6%) from 160 fishes. Comparative analysis of the nucleotide sequences and the deduced amino acids of MABV genome from wild fishes were similar to reference strains of MABV and distinguished with IPNV strains.

Shell Height Frequency using of Age and Growth of Blood Cockle, Tegillarca granosa (Linnaeus) in Yeoja Bay, Southern Coast of Korea (각고조성을 이용한 남해안 여자만 꼬막의 연령과 성장)

  • Chang, Dae-Soo;Moon, Tae-Seok;Jung, Min-Min
    • The Korean Journal of Malacology
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    • v.22 no.2
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    • pp.135-141
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    • 2006
  • This paper describes relative age and growth pattern of the blood cockle, Tegillarca granosa (Linnaeus) in Yeoja Bay, southern coast of Korea. The young shell of blood cockle that spawned from July to August reached 5.60 mm $({\pm}\;1.07)$ in shell height in October. Slow growing season was estimated to be from October to the next May with water temperature under $23^{\circ}C$. With warm water temperature in July to September, the growth was fast. The young shells reached 29 percentage of asymptotic shell height 11-15 months after spawning. Growth was estimated by von Bertalanffy growth function as follows. $I_t(sh_t)=46.1317\;(1-e^{-0.4997(t-0.5828)})$.

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A Study on the Polarization Potential Distrbution of a Steel Disc in the Water by Specific Resistance of Corrosion Circumstances (환경의 비저항을 고려한 수중 원강판의 분극전위분포에 관한 연구)

  • 김귀식
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.17 no.2
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    • pp.105-108
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    • 1981
  • The oceanic effect on the climate of the southern coast of Korea was analysed based on the sea surface temperature and in order to study relationships between the fluctuation of the sea surface temperature and that of climatic elements. Meteolorogical data from 1960 to 1979 were used. In the year when difference between the air and water temperature was maximum, the air temperature in southern coast was higher than normal year. A fluctuation of the sea surface temperature plays an important influence to determine the variation of the air temperature in the coastal area. Humidity of the coastal climate depends upon the oceanic effect in summer, but not in winter. This results may be due to prevailing wind effect. The oceanic effect on the precipitation in the coastal area is not found.

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Comparison of House Folkore in China, Korea and Japan (중·한·일 세 나라의 주거민속 연구 -조왕(竈王)-)

  • Kim, kwang-on
    • Korean Journal of Heritage: History & Science
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    • v.34
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    • pp.172-195
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    • 2001
  • This research on the house folklore in China, Korea, and Japan is focusing on a kitchen God that is common in these three countries. This god originated in China and has subsequently influenced Korea and Japan. Today, all three countries use the same name of this kitchen god which is called Youngwang(竈王) as its name has been spelled in Chinese. In China, this kitchen god has been believed in two different ways. The Han people have developed their belief in Youngwang while another creed has been originated from other ethnic groups. Because of the particular house style with upper stories of ethnic groups in the southern and southeast areas of China, a kitchen fireplace is centered in the house. Han people in China also worship painted depictions of kitchen gods. And the ethnic groups believe it has three stone legs for a fire box. These differing beliefs has bad influenced on Korea and Japan. The kitchen god of Cheju island (off the south Korea coast) is believed to be almost the same as among the ethnic groups in China Interestingly, form of belief in the kitchen god in Okinawa (off the south coast of Japan) is almost identical as in the southern area of China Custom in China. Korea, and Japan regarding the kitchen god symbolized family values healing, initiating a new daughter-in-law to reveging the kitchen god, etc. are all the very similar. A fireplace and its fire are very important and, have many taboo, attached. Existing rich tales of kitchen gods are similar in the three countries. Moreover, people in the three countries, think that the clay or time plaster of the fireplace with bring good luck on New Year's eve. However, Korea kitchen god features one thing that is different from those China and Japan, that is that water symbolizes the kitchen god in Korea. A painted kitchen god as they are popular in China, has influenced only some Buddhist temples in Korea.

Analysis of Seasonal Morphodynamic Patterns using Delft3D in Anmok Coast (수치모델링을 통한 안목해안에서 계절에 따른 지형변동 패턴 분석)

  • Kim, Mujong;Son, Donghwi;Yoo, Jeseon
    • Journal of Coastal Disaster Prevention
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    • v.5 no.4
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    • pp.183-192
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    • 2018
  • In recent years, coastal areas have been suffering from coastal erosion, such as destruction of coastal roads and military facilities. In this study, the Delft3D model was used to analyze the sediment transport pattern due to seasonal characteristics of summer and winter waves in Anmok beach of the East coast. Typhoon and high waves are mainly are coming from ENE direction in the summer season and the flows occur in the northward. In winter, high waves are incident from NE and the flows occur in the southward. These seasonal patterns were simulated by using Delft3D model. As for model input, reanalysis wave data of the past 38 years were used, and the seasonal patterns were analyzed by dividing the whole year into summer and winter season. The grid point of the 38 year reanalysis data is far from the Anmok beach, so the three model grid systems (wide grid -> intermediate grid -> detailed grid) are constructed. Most of the flows in the NW direction occurred in summer, but erosion and deposition was alternated along the coastline. In winter, sediment was deposited near Gangnung Port due to the southern flow and the southern port. Strong winter waves compared to summer tend to cause deposition around Gangnung Port throughout the year.

A Comparative Study on Machine Learning Models for Red Tide Detection (적조 탐지를 위한 기계학습 모델 비교 연구)

  • Park, Mi-So;Kim, Na-Kyeong;Kim, Bo-Ram;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1363-1372
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    • 2021
  • Red tide, defined as the major reproduction of harmful birds, has the characteristics of being generated and diffused in a wide area. This has limitations in detection only with the existing investigation method. Therefore, in this study, red tide was detected using a remote sensing technique. In addition, it was intended to increase the accuracy of detection by using optical characteristics, not just the concentration of chlorophyll. Red tide mainly occurs on the southern coast where sea signals are complex, and the main red tide control species on the southern coast is Cochlodinium polykirkoides. Therefore, it was intended to secure objectivity by reflecting features that could not be found depending on the researcher's observation and experience, not limited to visual judgment using machine learning techniques. In this study, support background machines and random forest were used among machine learning models, and as a result of calculating accuracy as performance evaluation indicators of the two models, the accuracy was 85.7% and 80.2%, respectively.