• 환경생물
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• 제37권1호
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• pp.68-71
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• 2019

An asteroid specimen that belongs to the genus Henricia was collected from the waters near Ongpo harbor, Jeju Island using fishing net on 24 January 2017. The specimen was identified as Henricia anomala Hayashi, 1973, which belongs to the family Echinasteridae and order Spinulosida. Henricia anomala was first described by Hayashi, 1973, who captured it from Sagami Bay at a depth of 110-116 m. This species can be distinguished from other Henricia species by short arms (R/r=4), abactinal spines lining the abactinal plates and bearing about two to five spinelets, closely meshed abactinal skeleton, composed of small rod-like and subtriangular plates, a narrow papular area containing one or two papulae, and adambulacral armature composed of five to seven bluntly pointed spinelets. This is the first report of Henricia anomala in Korea.

• Journal of Species Research
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• 제12권2호
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• pp.154-157
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• 2023

A specimen of Henricia was collected from the adjacent waters of Moseulpo, Jeju Island, Korea, using fishing nets. The specimen was identified as Henricia aspera Fisher, 1906, which belongs to the family Echinasteridae of the order Spinulosida. This species can be distinguished from other Henricia species by its broad arms (R/r=4.1), swollen arm base, three to seven short abactinal spines, and close-meshed formation of the actinal skeleton. This study has newly recorded H. aspera inhabiting the Korean fauna, bringing the total number of known Henricia species in Korea to 16. This study provides a description of the morphological characteristics of H. aspera with photographs of each part. Additionally, a table is presented that compares the morphological characteristics of H. aspera with closely related Henricia species.

• Ocean and Polar Research
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• 제30권1호
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• pp.79-87
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• 2008

Hydroacoustic technique was used to analyze spatiotemporal stability and distribution of demersal fish aggregations in the coastal region to overcome some limitations of the existing methods such as net and diving. The survey was carried out in the Baekeum Bay on the south coast of Korea in January 2007. The bottom depth in the study site ranges from 7 to 25 m. In order to outline aggregations of demersal fish initial scanning using 200 kHz split-beam transducer was randomly conducted over the large area. Having detected fish aggregation in the specific region, intensive acoustic survey of irregular star pattern was carried out along 14 transects across the area in question. The results of the acoustic survey show that all demersal fish aggregations are concentrated about 5 m from sea bottom having a slight slope and remain steady with no spatial or temporal variations during acoustic survey. The hydroacoustic method used in this study offers a new approach to understand vertical and horizontal distribution, spatiotemporal stability, and biomass estimate of demersal fish aggregations in coastal regions. Additionally, the number of individual fish estimated from in situ acoustic target strength data can be used to understand the standing stock of demersal fish aggregation.

• 우주기술과 응용
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• 제3권1호
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• pp.58-71
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• 2023

본 논문에서는 관성측정장치와 천측 항법을 활용한 수평 위치 추정을 위한 항법 시스템 설계에 대해 기술하였다. 우주 상에서 별은 천구 상에 널리 퍼져 있는 천체로서 별의 관측을 통해 자세 정보를 획득하는데 주로 사용되어 왔다. 하지만 별의 고도 정보를 통해 수평 위치에 대한 정보 또한 획득이 가능한데, 이는 천측 항법이라고 불리며 예전 항해사들이 바다 위 항해 중에 자기의 위치를 알아내던 원리와 동일하다. 특히 GPS 등의 사용이 불가능한 심우주에서는 비교적 관측이 쉬운 별을 통해 위치에 대한 정보를 획득하는 것이 중요하다. 따라서 본 논문에서는 수평 위치정보를 추정할 수 있는 항법 시스템을 소개하며 측정값을 활용하는 방식에 따라 약결합과 강결합의 두 가지 방식의 시스템을 설계하고자 한다. 시뮬레이션을 통해 설계된 시스템이 올바르게 수평 위치정보를 추정하는지 여부와 함께 약결합과 강결합 방식의 성능을 비교하여 추후 천측 항법을 활용한 항법 시스템 설계에 도움이 되고자 한다.

• 한국항해항만학회지
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• 제33권4호
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• pp.289-294
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• 2009

The living performances of crews and passengers in cabins have been less received attention, while Korea is a top leading country in ship building industry. To develop a high value added ships like 5-star cruisers, researches on the comfort and productivity in cabins should be carried out with urgent. The purpose of this study is to measure and analyze of the ship's indoor thermal conditions in spring, summer and winter, and also to compare the seasonal differences, of which conditions are supplied from and controlled by marine HVAC The temperature, humidity and air supply volume of 5 different needs of cabins on a training ship were measured through a year, which was launched at Dec. 2005 and totally 246 crews can go on board for education. The following results were obtained: (1)In the spring, the temperature in cabins was measured as $20{\sim}25^{\circ}C$ and humidity was below 30%. (2)In the summer, the temperatures was controlled at $21{\sim}27^{\circ}C$ in almost cabins and humidity was between $40{\sim}60%$ which is known as comfort conditions. (3)In the winter, temperature and humidity was maintained between $19{\sim}26^{\circ}C$, and humidity was between $10{\sim}50%$. (4)It is clear that the humidity conditions in cabins are not properly controlled at all through a year to satisfy the Comfort Standards provided by ASHRAE and/or ISO, In conclusion, humidification and dehumidification of cabins must be treated with importance for more comfort living and working environments for crews and passengers.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.48.1-48.1
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• 2009

In recent years, many candidates for extra-solar planet have been discovered from various measurement techniques. Fueled by such discoveries, new space missions for direct detection of earth-like planets have been proposed and actively studied. TPF instrument is a fair example of such scientific endeavors. One of the many technical problems that space missions such as TPF would need to solve is deconvolution of the collapsed (i.e. spatially and temporally) spectral signal arriving at the detector surface and the deconvolution computation may fall into a local minimum solution, instead of the global minimum solution, in the optimization process, yielding mis-interpretation of the spectral signal from the potential earth-like planets. To this extend, observational and theoretical understanding on the spectral bio-signal from the Earth serves as the key reference datum for the accurate interpretation of the planetary bio-signatures from other star systems. In this study, we present ray tracing computational model for the on-going simulation study on the Earth bio-signatures. A multi-layered atmospheric model and sea ice variation model were added to the existing target Earth model and a hypothetical space instrument (called AmonRa) observed the spectral bio-signals of the model Earth from the L1 halo orbit. The resulting spectrums of the Earth show well known "red-edge" spectrums as well as key molecular absorption lines important to harbor life forms. The model details, computational process and the resulting bio-signatures are presented together with implications to the future study direction.

• 생명과학회지
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• 제13권6호
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• pp.799-804
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• 2003

천연물에 포함되어 있는 에스트로겐 효과를 가지는 성분의 생체 내에서의 직접적인 효과를 검정하기 위하여, 에스트로겐 수용체를 발현하는 것으로 알려진 인체 유방암 세포주 MCF7에 에스트로겐에 반응성을 나타내도록 고안된 CAT 리포터 플라스미드를 도입한 in vitro 검출시스템을 사용하여 에스트로겐 활성을 측정하였다. 이미 여러 분야에서 그 기능성의 연구가 활발히 진행되고 있는 광합성 조류인 스피루리나(spirulina)와 파래 등의 해양식물을 대상으로 에스트로겐 반응 리포터 시스템을 이용하여 에스트로겐 활성을 측정하였다. 그 결과, 스피루리나 에탄올 추출물의 CAT 활성은 $500\mug/ml\; 와\; 50 \mug/ml$의 농도에서 표준물질인 $17\beta-estradiol$의 농도 $10^{-8}$ M과 비슷한 정도의 에스트로겐 활성 효과를 나타내었고, $5\mug/ml$의 농도에서는 표준물질인 $17\beta-estradiol$의 농도 $10^{-10}$ M과 비슷한 정도의 에스트로겐 활성 효과를 나타내었다. 하지만 파래 추출물의 경우에는 에탄올을 처리한 대조군과 비교하여 유의한 CAT활성 변화를 나타내지 않았다 한편, 불가사리와 새우 등의 해양동물을 대상으로 한 실험에서는 에탄올을 처리한 대조군과 비교하여 유의한 CAT 활성 변화를 나타내지 않았다. 이 연구 결과로 광합성 조류인 스피루리나에 에스트로겐 활성을 효과적으로 나타내는 생리활성성분이 포함되어 있을 수 있다는 가능성을 확인하였다.

• 한국수산과학회지
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• 제41권6호
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• pp.471-477
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• 2008

Development of egg, larvae and juveniles for the Pacific mackerel, Scomber japonicus are described following natural fertilization in the indoor tank of $25^{\circ}C$ water temperature. Following a routine hormone treatment technique for the brood stock, male and female mackerels were artificially matured by intramuscular injections of LHRHa at a dosage of $400{\mu}g/kg$ body weight (BW)+Domperidone at a dosage of $4{\mu}g/kg$ body weight (BW) to induce maturation in a separate aquarium and induced natural spawning. Fertilized eggs were ca. 1.0 mm in diameter; spherical in shape with a single oil globule; pelagic and non-adhesive. Hatching occurs 41 hours after fertilization at $23-24^{\circ}C$. The newly hatched larvae was 3.03 mm in average total length (ATL), the mouth and anus were not open, oil globule located in posterior end of yolk sac, and preanal length was 42.8% of TL. The larvae measuring 2.89 mm ATL, almost absorbed yolk sac and oil globule material in 2 days after hatching, in which the mouth and anus were open. Melanophores, branch or star in shape were observed on the top of head, peritoneal region and along the ventral contour. In 13 days after hatching, the larvae was 6.88 mm ATL, its posterior end of notochord began to flex upward, finfold of caudal fin appeared, jaw teeth were already formed. In 19 days after hatching, the larvae was 7.71 mm ATL completed only caudal fin rays (9+8), and preanal length was 49.4% of TL. In 37 days after hatching, the larvae was 27.4 mm ATL already completed all the fins, and preanal length was 59.9% of TL.

• 한국기계가공학회지
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• 제13권5호
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• pp.43-49
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• 2014

This study was carried out to improve the design of an intercooler for a small marine diesel engine. Diesel engines for small marine ships have mainly been developed by changing the structure of the vehicle engine. Sea water was most commonly used in the intercooler of small marine diesel engines to cool the hot air compressed by the turbocharger. In this study, the intercooler is modeled and simulated using STAR-CCM+ in order to find optimal data for the design of an intercooler. In the results, the temperature differences between the data from a numerical analysis and experimental data were $0.38^{\circ}C$ in the hot air outlet and $3.63^{\circ}C$ in the cooling water outlet. Therefore, it was confirmed that both analysis and experimental results need to be considered when designing an intercooler. A closer degree of similarity in the two datasets can improve the confidence in the design of these intercoolers.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.232-238
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• 2009

The objective of this study is to investigate the suitable design for a domestic CWP pump, which is used in cooling-water intakes for the unit 3 and 4 of Yeonggwang nuclear power plant. All the simulations are performed, using CFD method with a commercial code STAR-CCM+ version 3.02. After modeling a present design of the pump, the flow around the rotating blade was calculated by using quasi-static method and sliding mesh method with the almost same condition as an actual state. Based on fundamental simulations with various depth of sea water, the reference pressure for the boundary condition of the present study was decided. To verify the reliability of the calculation results, the suction flow rate of the data was compared with that of the experimental data. As a result of this comparison, it is confirmed that two results are fairly consistent. For the improvement of the suction flow rate, computational analysis was done by changing a flow channel and blade shapes. It is shown that the suction flow rate of the new pump was improved.