• Journal of Species Research
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• 제6권spc호
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• pp.75-93
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• 2017

As a part of a survey of indigenous biological resources of Korea, 30 marine benthic foraminiferal species belonging to 24 genera and seven orders (Astrorhizida, Lagenida, Lituolida, Miliolida, Robertinida, Rotaliida and Textulariida) were identified. Bottom sediment samples were collected from eight stations on the west and east coast of South Korea, in April 2015 and May 2016, respectively. Ten species belonging to nine genera and five orders (Lagenida, Lituolida, Robertinida, Rotaliida, Textulariida) were identified in the Yellow Sea. Among these taxa, Rotaliida was the dominant order, represented by four species: Evolvocassidulina tenuis (Phleger & Parker, 1951), Cibicides mabahethi Said, 1949, Cibicides pseudolabatulus Perelis & Reiss, 1975 and Cibicidoides barnetti Bermudez, 1949. Twenty species belonging to 15 genera and five orders (Astrorhizida, Lagenida, Lituolida, Miliolida, and Rotaliida) were identified from the East Sea and the Lagenida was the dominant order, represented by 11 species: Lagena strumosa Reuss, 1858, Lagena nebulosa (Cushman, 1923), Lagena striata var. semiornata Reuss, 1863, Procerolagena cylindrocostata Albani & Yassini, 1989, Fissurina bispinata $Ujii{\acute{e}}$, 1963, Oolina laevigata d'Orbigny, 1839, Polymorphina amplissima McCulloch, 1977, Polymorphina subelliptica McCulloch, 1977, Guttulina succincta McCulloch, 1977, Guttulina neoproblema McCulloch, 1977 and Lagenosolenia obtecta McCulloch, 1977. The findings described here increased the number of foraminiferal species in Korea to approximately 1060, and contribute to our understanding of the diversity of foraminifera in Korean waters.

• Ocean Systems Engineering
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• 제12권1호
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• pp.23-38
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• 2022

In this paper, a pitch-type wave energy converter (WEC-rotor) is investigated in irregular wave conditions for the real sea testing at the west coast of Jeju Island, South Korea. The present research builds on and extends our previous work on regular waves to irregular waves. The hydrodynamic characteristics of the WEC-rotor are assessed by establishing a quasi-two-dimensional numerical wave tank using computational fluid dynamics by solving the Reynolds-averaged Navier-Stokes equation. The numerical solution is validated with physical experiments, and the comparison shows good agreement. Furthermore, the hydrodynamic performance of the WEC-rotor is explored by investigating the effect of the power take-off (PTO) loading torque by one-way and two-way systems, the wave height, the wave period, operational and high sea wave conditions. Irrespective of the sea wave conditions, the absorbed power is quadratic in nature with the one-way and two-way PTO loading systems. The power absorption increases with the wave height, and the increment is rapid and mild in the two-way and one-way PTO loading torques, respectively. The pitch response amplitude operator increases as the wave period increases until the maximum value and then decreases. For a fixed PTO loading, the power and efficiency are higher in the two-way PTO loading system than in the one-way PTO loading system at different wave periods.

• 산업기술연구
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• 제25권A호
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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.

• 한국동물학회지
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• 제5권2호
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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.

• 한국어병학회지
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• 제31권1호
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• pp.1-8
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• 2018

Causative agent of infectious hematopoietic necrosis (IHN) belonging to genus Novirhabdovirus (Rhabdoviridae). Economic losses caused by IHNV are serious in mainly Oncorhynchus spp. including rainbow trout O. mykiss and Atrantic salmon Salmo salar. IHNV was initially found by endemic presence in U.S. West Coast for sockeye salmon fry O. nerka and chinook salmon fry O. tshawytscha in the 1950s, and it has spread to Japan, Korea and Taiwan in the 1970s, and also to Italy and France in the 1990s. Currently, IHNV is detectable in many parts of the world, including Russia and South America. Mortality due to IHNV infection in fish with ${\leq}0.5g$ of body weight reaches 60% to 100%, while the mortality reduces by fish growing. In recent years, onset of IHNV infection has increased also in fish with large sizes. Here, we introduce molecular epidemiology and virulence changes of IHNV in East Asia, furthermore, we discuss on future prospects in IHNV researches.

• 한국수산과학회지
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• 제54권2호
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• pp.208-217
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• 2021

This study described the fishing characteristics of Pacific herring Clupea pallasii and examined the relationship between its catch and sea temperature in Korean waters from 1970 to 2019. Although the herring catch in Korean waters stayed below 1,000 tons per year from the mid-1970s to mid-1980s, the catch in the winters in the East Sea of Korea started to increase markedly after 1987-1988, when the sea surface temperature (SST) seemed to shift to a warmer regime. Since the mid-2000s, overall, herring was caught throughout the year in the East Sea and eastern South Sea of Korea, and its catch significantly increased by around 30,000 tons per year. The main fishing grounds of herring in the poor fishing years until the mid-1980s were possibly formed in the western offshore of Korea, and subsequently the fishing grounds were distributed in the eastern coast of Korea. While the standardized catch per unit effort (CPUE) for two main fisheries of herring catch was significantly correlated with the herring catch since the 2000s, there was a gradual decline since the 2010s. The herring catch in the East Sea had significant positive correlations with SSTs, but that in the West Sea had a significant negative correlation.

• 수산해양기술연구
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• 제60권1호
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• pp.18-26
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• 2024

In this study, we estimated the distribution density of giant jellyfish in coastal waters of Korea in 2023 and compared the occurrence of giant jellyfish over four years. In May, the giant jellyfish were mainly distributed in the waters of the Yangtze River outflow, and in July, they were highly distributed in the west of Jeju Island and near the south coast of Korea. In addition, when comparing the distribution densities of giant jellyfish in Korea over four years, both acoustic and sighting surveys showed that the highest density of jellyfish occurred in 2021.

• 한국전자통신학회논문지
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• 제17권5호
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• pp.815-824
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• 2022

해상풍력발전과 같은 간헐성 재생에너지원의 급격한 성장은 바다를 횡단하는 장거리의 전기에너지의 변환 필요성을 증가시키고 있다. 넓고 깊은 바다에 걸쳐서 장거리 대용량 전력송전을 위한 해법중의 하나는 HVDC 해저 전력케이블을 사용하는 것이다. 그러나 교류자계가 없는 직류전력 케이블의 다양한 해양조건을 갖는 연속허용전류와 관련한 표준이나 연구가 없다. 본 연구에서는 대표적인 두 종류의 해저케이블 모델과 남해안과 서해안 두 지역의 해양 요건을 가정하여 직류케이블의 연속허용전류를 모의하였다. 모의 결과를 보면 직류케이블의 연속허용전류는 해저 지반 깊이에 기반한 감소 구배 특성을 갖고 있는 것을 확인하였다.

• 한국해양학회지:바다
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• 제24권4호
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• pp.495-508
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• 2019

조석현상이 뚜렷한 연안에서 항해, 연안 구조물 설계, 해양영토 획정, 침수범람 예보 등을 위하여 여러 조위 기준면들(tidal datums)이 사용된다. 우리나라 수로학 분야와 해안공학 분야에서는 수심을 측량하는 기본 수준면(datum level)으로 약최저저조위(ALLW)를 사용하고, 해안선과 안전수직높이(vertical clearances) 기준면으로는 약최고고조위(AHHW)를 사용하고 있다. 그러나 최근에 미국, 호주, 영국을 포함하여 국제적으로는 최저 천문조위(LAT)와 최고 천문조위(HAT)를 기본 수준면과 안전수직높이의 기준면으로 사용하고 있다. 이 연구에서는 서해안과 남해안 9개 조위 관측소에서 19년(1999-2017년) 동안 1시간 간격으로 관측한 해수면 높이 자료를 '19년 벡터평균 분석', '19년 연속 분석', '1년 연속 분석' 방법으로 각각 1분 간격으로 19년간 예측한 조위로부터 LAT와 HAT를 계산하였다. 이 연구에서는 19년 연속 관측자료의 조석 조화분해와 19년 연속 조석 예측에 모두 적합한 UTide 프로그램을 사용하였다. 각 조위 관측소에서 '19년 벡터평균 분석'과 '19년 연속 분석' 방법으로 각각 계산한 LAT 또는 HAT 값들의 차이는 대부분 ±1 cm 미만으로 큰 차이를 보이지 않았으며, 이 두 방법은 서로 거의 일치하는 결과를 생산하였다. 반면에 각 조위 관측소에서 19년간 연속 관측한 자료를 연별로 19개로 나누어 각각 1년 자료씩 조석 조화분해한 후 각각 19년간 조위를 예측한 '1년 연속 분석' 방법은 서로 크게 다른 19개의 LAT와 HAT 값들을 산출하였으며, 그 19개들의 표준편차는 3~7 cm이었다. '1년 연속 분석' 방법으로 구한 이들 값들은 '19년 연속 분석' 방법으로 산출 값과 비교하면 서해안과 남해안에서 LAT는 -16.4~10.7 cm의 차이를 보였으며, HAT는 -8.2~14.3 cm의 차이를 보였다. 계산된 LAT와 HAT를 ALLW와 AHHW와 정량적으로 비교했을 때, 서해안과 남해안에서 LAT는 ALLW보다 평균적으로 46.2 cm 더 낮았으며, HAT는 AHHW보다 평균적으로 33.6 cm 더 높았다. 이러한 차이에 가장 크게 기여하는 분조는 ALLW와 AHHW 계산에 고려되지 않은 진폭이 비교적 큰 S_a와 N₂ 분조이었다. 또한 천해분조가 강하게 발달한 내만에서는 M₄와 MS₄ 분조가 추가적으로 그 차이에 상당히 기여하였다. LAT와 ALLW 간 차이와 HAT와 AHHW 간 차이가 같지 않은 이유는 ALLW와 AHHW를 계산할 때는 주요 4대 분조의 진폭만을 사용하지만 LAT와 HAT를 계산할 때는 실질적으로 67개 분조의 진폭뿐만 아니라 지각도 사용하기 때문이다.

• 한국도로학회논문집
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• 제15권3호
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• pp.103-115
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• 2013

PURPOSES: The purpose of this study is to develop a method for distribution between superelevation and side friction factor by increasing design speed. METHODS: First of all, a method for distribution between superelevation and side friction factor and a theory for the functional formula of side friction factor in compliance with horizontal radius applied in South Korea and the United States are considered. Especially, design speed of 140km/h and numerical value of design elements are applied to the theory for the functional formula of side friction factor in AASHTO's methods. Also, the anxiety EEG upon running speed is measured to reflect ergonomic characteristics through field experiments at seven curve sections of the West Coast Freeway, and this data is applied to graph for the functional formula of side friction factor. RESULTS : Matching side friction factor against the anxiety EEG, the results that a critical points of driver's anxiety EEG sharply increase locate under existing parabola are figured out. CONCLUSIONS : Therefore, we could get a new type of the functional formula that driver's driving comfortability is guaranteed if the existing the functional formula of side friction factor goes down under boundary of the critical points of the anxiety EEG.