• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.24-30
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• 2010

Space solar sails are a form of spacecraft propulsion using the radiation pressure of light from a star or laser to push enormous ultra-thin mirrors to high speeds. With respect to it, U.S.A, Japan, E.U. and Russia, etc. have performed a substantial research and the space flight test. On May 2010, JAXA succeeded in launching the world's first interplanetary solar sail spacecraft "IKAROS" to Venus. Currently, solar sail propulsion is aimed chiefly at accomplishing a number of non-crewed missions in any part of the solar system and beyond. This paper presents the technology trend of advanced countries on the development of the solar sails as a new propulsion method for the space investigation and travel.

• 한국해양학회지
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• v.25 no.2
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• pp.96-105
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• 1990

To study the fish larval community in the coastal waters of the mid-east Yellow sea, samples were collected with Bongo net at 13 stations between Chonsu Bay and Keum Estuary from July, 1985 to June, 1986. total of 45 taxa of fish larvae were occurred. the predominant species was Enedrias fangi accounting for 45.2% of the total abundances, and the next were Engraulis japonicus (27.5%), sardinella zunasi (10.6%), Callionymidae spp. (4.6%), Sillago japonica (3.0%), Favonigobius gymnauchen (1.9%), and Acentrogobius pflaumii (1.8%). These 7 taxa constituted 94.6% of the total abundances. The monthly abundances showed two peaks in July and January. Species diversities were very low from January to April when E. fangi predominated.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.34-42
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• 2005

An overview of 30 feet sailing yacht design is presented, with an emphasis on the factors contributing to start-up popularization. After prescribing the configurations of the purposed yacht, the design of the hull form with a rudder and a keel, are schematically described. Also the determinations of the dimensions of the sail and rig are performed. Finally this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.512-519
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• 1999

Seasonal variation in species composition and abundance of demersal fish in Yongil Bay were determined by analyzing samples collected using an otter trawl from January to October 1991. Of 59 species identified, Repomucenus lunatus, Tridentiger trigonocephalus, Repomucenus heguenini, Ammodytes personatus and Sillago japonica were dominated in abundance. Number of spiecies and biomass were low in winter and high in spring and summer. Species composition did not show spatial variation but showed seasonal variation. Number of spicies, abundance in number of individuals ($630 inds./10^3\;m^2$) and in biomass ($13,131g/10^3\;m^2$), and species diversity (2.00-2.54) of fish in Yongil Bay were higher than those of the coastal waters in the Yellow Sea or in the South Sea of Korea.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.60-66
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• 2006

Now, on developing COMS(Communication, Ocean and Meteorological Satellite) has solar panel on the south panel only. Therefore, the wheel off-loading has to be performed periodically to reduce a induced momentum energy by a asymmetric solar panel. One of two East/West station keeping maneuver to correct simultaneously longitude and eccentricity, orbit corrections may be performed during one of the two wheel off-loading manoeuvres per day to get enough observation time for meteorological and ocean sensor. In this paper, we applied a linearized orbit maneuver equation to acquire maneuver time and delta-V. Nonlinear simulation for the station keeping is performed and compared with general station keeping strategy for fuel reduction.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.71-79
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• 2007

This study is intended to investigate the superyacht exterior design style from the viewpoint of marine architectural design. Especially it is focused on the exterior profile design of superyachts. Superyachts are passenger vessels whose hull exceeds 24m. They are a kind of luxurious leisure ships. Marine architectural designer can contribute in the field of exterior and interior design of superyachts. In this study we analyze outboard profile of 32 superyachts and extract key design elements of exterior profiles. Those are sheer line, stem line, bow line, house line and windows.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.377-378
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• 2022

본 연구는 폐그물, 폐현수막, 비닐, 캔 등을 활용한 친환경 패션 소품을 제작하기 위한 선행연구로, 패션산업에서의 환경문제와 친환경 패션 브랜드에 대해 분석해보고자 하였다. 이를 통해 친환경 패션 소품 제작에 필요한 기초자료를 얻고자 하였다. 연구는 국내 포털사이트에서 '친환경 패션 브랜드', '패션산업의 환경오염' 등의 단어를 입력하여 검색되는 기사를 중심으로 진행되었다. 패션산업은 생산과 소비 과정에서 수질, 대기오염을 유발하며, 쓰레기 문제 등을 유발하였다. 제조과정 중 엄청난 양의 탄소를 발생시키며, 세탁과정에서는 미세플라스틱을 방출하여 수질을 오염시키는 것으로 나타났다. 친환경 패션 브랜드에 글로베 호프, 프라이탁, 스텔라 맥카트니, 파타고니아, 비건 타이거, 낫 아워스 등이 있다. 광고 현수막, 군복, 안전벨트, 공장작업복, 병원 이불, 보트의 돛, 자동차 방수포 등을 활용하여 다양한 가방, 파우치, 핸드백 등의 패션 아이템을 제작 판매하고 있다. 이 외에도 비건 소재를 사용하고 동물성 소재와 PVC 소재를 사용하지 않는 등 패션업계에서도 환경오염을 줄이기 위한 다양한 노력을 기울이고 있는 것으로 나타났다.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.1
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• pp.68-77
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• 2009

In this study it will be discussed how to solve the problem of discomfort from rolling motion on the small fishing boats. Up to now, the equipments of reducing rolling system can be examined by various case, but difficult to apply small vessel by function, space and costly establishment. A way of improving the feeling of getting on a boat through the equipped sail at stern edge of bulwark top was researched and developed. The author has tested the sailing performance of the experimental skiff boat, from the signals obtained by the inclinometer in irregular waves and compared with the results got in sail on and off mode operation for 10 minutes duration at the conditions of stop and underway. These data has been analyzed in the application statistical methods. Eventually we summarize the analyzed results obtained from the vessel while stationary and underway for two cases, the vessel with a sail and the vessel without a sail. The field test was done in Jeju outer harbor. The ratio of the motion responses at resonance for the sail with and without cases indicate that under given conditions the motion was reduced by the efficiency of diminution is 4.726%, 2.792% in the stopping and 11.663%, 3.282% in the underway and mean rolling periods are 2.158, 2.142, 2.421, 2.412sec. and 1.968, 1.963, 2.089, 2.051sec. respectively. Consequently the efficiency of diminution was higher when the ship is underway and rolling periods got longer in the equipped sail.

• Korean Journal of Ichthyology
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• v.26 no.1
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• pp.42-49
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• 2014

A total of 4 pelagic eggs and 24 larval fish species were collected in Masan Bay. Engraulis japonicus eggs predominated in pelagic eggs. Abundant larval fishes were Omobranchus elegans, Scomber japonicus, Acanthogobius flavimanus, Hexagrammos otakii, Repomucenus sp., Scartella cristata and Gobiidae sp., and these 7 species accounted for 78.5% in the total number of individuals. Temporal and spatial variation in both species composition and abundance of was large: the peak abundances of pelagic eggs and larval fishes occurred in July 2007, whilst these were lowest in February 2007. Higher abundance of ichtyoplankton were at station 5 than those of other stations. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature. Pelagic eggs and larval fishes varied among stations between with shallower inner stations and deeper outer stations with physical characteristics such as depth and local topography.

• 한국해양학회지
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• v.23 no.4
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• pp.184-193
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• 1989

To study the pelagic fish egg community in the mid-east coastal waters of the Yellow Sea, pelagic eggs were sampled with Bongo net at 13 stations from Chonsu Bay to Keum Estuary from July, 1985 to June, 1986. Nineteen taxa of pelagic eggs were collected. Among them, 7 taxa were identified to the species level, and 2 taxa to the family level. Engraulis japonica was the most abundant species with 89.5% of the total eggs; Sillago japonica was 2.5%; Clupanodon punctatus, 2.4%; Herklotsichthys zunasi, 1.7%; Callionymidae spp., 1.6%. These 5 taxa occupied 97.7% of the total eggs. Pelagic eggs occurred from April to October. In June and July, their abundances were high, but the species diversities were low as E. japonica eggs were predominant. The range of spawning temperature for each taxa were estimated from the occurence pattern of the pelagic eggs.