• 한국어병학회지
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• 제22권1호
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• pp.67-73
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• 2009

양식산 복어에서는 tetrodotoxin(TTX)가 존재하지 않는다고 일반적으로 생각되고 있다. 본 연구에서는 실제로 양식산 황복(Takifugu obscurus)에는 TTX가 존재하지 않는지 확인하기 위해 생쥐를 이용한 bioassay로 여러 장기를 동시에 분석하였다. 자연산에서는 동물이 치사하는 수준의 독력을 함유한 시료가 있었으며 정소>간장>장>근육>피부의 순으로 독력이 확인되었다.양식산 시료에서는 TTX의 미량존재로 추정되는 졸림, 행동둔화, 후지마비 등의 증상이 나타났지만 치사동물은 발견되지 않았다. 이 결과는 양식 산 황복에서 TTX가 매우 낮은 농도로 존재할가능성을 제시하지만 기기분석법을 이용한 정확한 정량이 필요하다고 판단된다.

• Fisheries and Aquatic Sciences
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• 제24권9호
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• pp.311-317
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• 2021

Inclusion effect of various levels of jack mackerel meal (JMM) acting as feed attractants and/or stimulants in diets on the growth, feed consumption, feed utilization and whole body composition of rockfish was investigated. Three hundred juvenile rockfish were randomly allocated into 15 flow-through tanks. Five experimental diets supplemented with JMM at 0%, 1%, 3%, 5%, and 10% at the expense of anchovy meal were prepared and referred to as the JMM0, JMM1, JMM3, JMM5, and JMM10 diets, respectively. Weight gain, specific growth rate (SGR) and feed consumption of fish tended to improve with dietary levels of JMM. The greatest weight gain, SGR and feed consumption were observed in fish fed the JMM10 diet, followed by the JMM5, JMM3, JMM1, and JMM0 diets, in that order. Condition factor (CF) of fish tended to improve with dietary inclusion levels of JMM. Growth performance, feed consumption and CF of fish tended to improve with dietary inclusion levels of JMM ranging from 0% to 10%.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1037-1043
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• 2015

In recent years, Floating Liquefied Natural Gas (FLNG) Unit have attracted considerable attention. Generally, liquefied natural gas (LNG) units are produced in onshore liquefaction terminals from gas supplied from onshore gas fields or large-scale offshore gas fields near the coast. However, the development of these gas fields has approached saturation. Large-scale offshore gas fields far from the coast, as well as undeveloped medium- and small-scale offshore gas fields, have recently attracted attention. Among several proposed concepts, the floating LNG plant in the form of the FLNG system was chosen for further evaluation and development, considering worldwide receiving infrastructure. The design of a 2.5 million tonne per annum FLNG unit has been completed with a capacity corresponding to that of modern onshore liquefaction plants. Various simulation tests were performed to evaluate the performance of the electrical power plant, focusing on the efficiency of the electrical system to secure the aspects of plant safety. This design study analyzes the electrical system for the FLNG unit to improve the safety of operation and maintenance in the field.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.95-98
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• 2007

본 논문은 W-대역에서 유전손실 재료인 $TiO_2$의 전파흡수 특성을 분석하였다. 먼저 전파흡수체 샘플을 손실재료로 $TiO_2$ 와 바인더로 CPE를 사용하여 조성비별 제작하고, 네트워크 아날라이저를 이용하여 측정한 S-parameter로부터 $\ell-2\ell$ 법을 이용하여 재료정수를 계산하였다. 그리고 샘플들의 재료정수와 전파흡수 특성을 분석한 결과 조성비 $TiO_2:CPE=70:30wt.%$에서 우수한 전파흡수 특성을 보임을 확인하였다.

• 한국환경과학회지
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• 제25권3호
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• pp.373-383
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• 2016

The aim of this study is to determine the exposure concentration of tetrabromobisphenol A(TBBPA) in southwestern coast and their photodecomposition rate. Also, it is to identify the radical species of the photodecomposition of TBBPA and their reactive byproducts using the electron spin resonance(ESR) method. TBBPA was not detected in any of the sea water samples from Mokpo, Gunsan, or Goheung. The sediment samples from Mokpo contained not detection(N.D)~50.0 ng/g dry wt., while those from Gunsan contained N.D~28.5 ng/g dry wt. and those from Goheung contained N.D~7.3 ng/g dry wt. The photodecomposition rates were $2.56{\times}10^{-6}/hr$ by visible light(400 nm), $7.98{\times}10^{-6}/hr$ by ultraviolet light(300 nm <), and $6.78{\times}10^{-6}/hr$ by sunlight. Also, we confirmed that singlet oxygen and hydroxyl radicals are the key reactive oxygen species at wavelengths greater than 400 and 300 nm, respectively. This study shows that the main byproducts formed during irradiation at wavelengths above 300 nm are 2,6-dibromobenzosemiquinone radical(2,6-$DBSQ{\cdot}^-$) and g-value 2.0048 doublet spectrum.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.896-906
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• 2020

Wood deterioration experiments were carried out for 6 months in an intertidal zone of South Korea to monitor the changes in the chemical properties of two types of species, Korean red pine and sawtooth oak. The results of FT-IR spectra and XRD patterns have shown that the chemical properties of the wood did not change significantly during the 6-month burial period. However, the brightness of the surface decreased after burial; the value of the sawtooth oak sample was lower than that of the Korean red pine sample owing to an accumulation of inorganic compounds in cell lumen as observed by ICP analysis. Among the inorganic compounds, sodium and sulfur concentrations increased significantly over the burial period compared with the control. Further, the maximum moisture content decreased from 199% to 136% in the Korean red pine and 62% to 60% for the sawtooth oak. Nevertheless, the major chemical composition of both the wood species did not change significantly during the 6-month burial period, whereas, the crystallinity decreased with an increasing burial period owing to an accumulation of inorganic compounds in the lumen.

• 한국항해항만학회지
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• 제26권1호
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• pp.28-34
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• 2002

해면에 난반사되어 돌아오는 신호는 잡음이 되는데, 이를 클러터(Clutter)라 한다. 클러터는 레이더 화면에 백색 가우시안 잡음과 같은 형태로 나타나게 되며, 이들은 선박용 레이더의 탐지 효율을 저하 시킨다 따라서 클러터 제거를 위한 연후는 안테나의 개선 또는 여러 종류의 필터 등을 통해 환발하게 진행되고 있다. 본논문에서는 선박 레이더와 탐지 효율을 향상을 위하여, 웨이브렛(Wavelet)과 수리형태학(Morphology)의 $3{\times}3$SQ(Square) 형태소를 적용한 메디언 필터를 사용하여 조난 또는 구조 선박의 수색을 용이하게 할수 있는 알고리듬을 제안한다.

• ALGAE
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• 제26권1호
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• pp.61-71
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• 2011

Thirty populations of Chondrus crispus Stackhouse from Nova Scotia were collected during the years 1993 to 2011. Taken from estuaries, wave exposed open coasts, high intertidal rock pools and shallow subtidal habitats, the populations were evaluated for relative abundance of tetrasporophytic and gametophytic life history phases. Over 2,800 thalli were characterized using the resorcinol-acetal test to distinguish the kappa- and lambda-carrageenan containing fronds of gametophytes and tetrasporophytes, respectively. These populations had $77{\pm}5%$ gametophytes (mean ${\pm}95%$ confidence interval), with most populations having gametophyte : sporophyte ratios ranging from 2 : 1 to 9 : 1. No population had a dominance of tetrasporophytes, although two populations had 1 : 1 ratios. A meta-analysis of our data along with previously published accounts showed no significant changes in gametophyte dominance with respect to hypothesized gradients of wave exposure, salinity, or water depth. Significant changes occurred in ratios at five sites where replicate sampling occurred in different years. We conclude that C. crispus in Maritime Canada has a natural ratio of 3 : 1 or greater in stable conditions, and that lower ratios represent recovery from disturbance in which bare substratum is created that is subsequently colonized by carpospores from remaining gametophytic thalli.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.717-722
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• 2009

대한민국은 국가경제발전의 기반을 무역에 두고 있는 대외 지향적 통상(通商)국가이다. 현재 한국의 무역은 화물량 기준 거의 100%를 해운에 의존하고 있다. 한나라의 경제 특성을 나타내는 지표로서 '무역의존도'가 있는데 2007년도 한국의 무역의존도는 75.09%로서 일본의 30.15%의 약 2.5배, 중국의 67.07%에 비해 현저하게 높은 세계최고 수준이다. 이는 한국경제 나아가 한국의 안전과 발전이 절대적으로 해양을 통한 무역에 의존하고 있다는 의미로 이해할 수 있다. 대외무역에 국가의 사활을 걸고 있는 한국에서 국가해양활동의 안전이 확고하게 지켜지지 못해 무역에 차질이 발생한다면 이는 국가 경제 나아가 국가안보에 심대한 악 영향을 미칠 수밖에 없다. 반면 최근 소말리아 근해 해적의 피해확대로 한국은 주력 전투함을 파견하여 한국선박보호와 인근해역의 해양안전유지를 위해 국제적 해양안보활동에 참여하고 있다. 이는 한국의 국가경제활동이 전 세계로 확대됨에 따라 해양에서의 안전도 다방면에서 위협을 받고 있어 군함까지 파견해야 할 정도로 위협이 확대되고 있다는 방증이기도 하다. 이에 반해 한국에서는 해양안보에 대한 국민적 관심과 체계적인 대비책개발을 위한 노력이 아직은 미흡한 실정이다. 따라서 한국은 지금부터라도 국가적 차원에서 해양안보에 대한 관심과 대비책마련을 본격적으로 서둘러야 한다. 우선 한국은 해양안보위협을 북한으로 부터의 군사적 위협과 동일한 개념의 안보문제로 간주하여 대비해야 나가야 할 것이다. 또한 현재 정부 각 부처에 분산된 해양안보 관련 기능을 유기적으로 통합하여 수행할 수 있는 중심기구의 설치를 검토하여야 할 것이며, 국제적인 해양안보노력에도 적극적으로 참여함으로써 해양의 안전을 확고하게 유지하여 한국의 지속적인 국가번영을 보장하여야 한다.

• 한국발생생물학회지:발생과생식
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• 제20권4호
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• pp.331-347
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• 2016

Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were $L_{\infty}=30.2mm$, K=3.22/year, and ${\tau}_0=-0.05$. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka.