• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.11-23
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• 1991

To study the distribution of inhthyoplankton in the adjacent water of Wolsong, samples were collected using Bongo net from the surface water in November of 1989, and February, May and July of 1990. Fish eggs were divided into Engrualis japonicus, Callionymidae, Maurolicus muelleri, Konosirus punctatus, and others. The dominant species of fish eggs were Maurolicus muelleri and Callionymidae accounting for 60.1% and 13.7% of the total egg abundance, respectively. Total of 21 taxa of fish larvae occurred. The predominant species was Engraulis japonicas accounting for 61.2% of the total lavae, and bollowed by Callionymidae(11.9%). Other major species were Maurolicus muelleri, Gobiidae sp., Ammodytes personatus, Sebastes inermis, S. Pachycephalus, Scartella cristata, and Sebastiscus marmoratus. These 9 taxa constituted 96.5% of the total larvae collected. In this area, where upwelling occasionally occurs the distribution of fish eggs and larvae appeared to be affected by the transport of the surface water during the upwelling period.

• Journal of Ocean Engineering and Technology
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• v.30 no.1
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• pp.57-67
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• 2016

As a new technical approach, an attempt was made to realize a photovoltaic system for an eco-environmental leisure ship by simultaneously actuating nine photovoltaic solar panels in association with the application of a sail-controlling system using wind energy. In this approach, the photovoltaic system consisted of a solar module, an inverter, a battery, and the relevant components, while the sail-controlling device was equipped with sail up/down and mast turning systems. The previously mentioned eco-environmental leisure ship utilizes a photovoltaic hybrid system that uses solar and wind energy as renewable energy sources. Furthermore, this research included a performance evaluation of the manufactured prototype, the acquisition of the purposed quantity values, and development of the purposed items. The significant items, including the sail up/down speed (seconds) and mast turning angle (degrees) were evaluated for a performance test. A wind direction sensitivity of 90% and maximum instant charging power of 900 W were also obtained in the process of the performance evaluation. In addition, the maximum sail time was also evaluated in order to acquire the optimum value. The performance evaluation showed that the prototype with a photovoltaic hybrid system was suitable for sailing an eco-environmental leisure ship using solar and wind energy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.7
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• pp.609-618
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• 2015

This paper discusses the attitude determination of the CNUSAIL-1 cube-satellite. The primary mission of the CNUSAIL-1 is sail deployment and operation in low Earth orbit, and the secondary mission is to look into influence of the sail deployment on satellite attitude and orbit. The attitude determination strategy is proposed depending on three mission phases, and its performance and applicability are verified through numerical simulations. This study considers the following sensors: Sun sensors and a three-axis magnetometer as attitude reference sensors, and a three-axis MEMS gyroscope as an inertial attitude sensor. Because sensors used for cube satellites have relatively low performances and worse noise characteristics, an Extended Kalman filter (EKF) is applied to attitude determination. Additionally, it has the merits to deal with the Gaussian noises and to predict the attitude even with no measurements from reference attitude sensors, especially in the eclipse of the cube satellite. The performance of the EKF is compared to a deterministic attitude determination technique, QUEST(QUaternion ESTimation).

• 정보화사회
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• s.101
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• pp.16-17
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• 1996

"한국정보보호센터"가 정보통신부와 국가안전기획부 등의 전적인 후원아래 지난 4월 10일 출범했다. 멀지않은 미래에 펼쳐질 사이버스페이스라는 망망대해에서 벌어질 각종 하이테크 범죄를 평정하기 위해 돛을 올린 것이다. 이같은 정보보호센터의 설립에 대한 움직임은 몇년 전부터 있었으나 지난 95년 8월 4일 정보화촉진기본법이 공포되면서 본격화됐다.

• Social Workers
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• no.2 s.46
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• pp.24-25
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• 2006

지난 10월 강진으로 파키스탄 북부지역은 8만 여명이 사망하고 35만 명의 이재민이 발생하는 엄청난 피해를 입었다. 사회기반 시설이 무너져 어린아이들조차 얇은 여름용 텐트 하나에 의지해 추운 겨울의 혹한을 견디며 우리의 도움을 필요로 하고 있다. 이게 한국사회복지사협회는 ‘파키스탄 희망의 워크캠프’를 통해 한국 최초로 사회복지사가 직집 해외로 나가 구호활동을 펼치게 하였다.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.101-104
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• 2008

The sailfish is the fastest sea animal, reaching its maximum speed of 110km/h. On its skin, a number of V-shaped protrusions pointing downstream exist. Thus, in the present study, the possibility of reducing the skin friction using its shape is investigated in a turbulent boundary layer. We perform a parametric study by varying the height and width of the protrusion, the spanwise and streamwise spacings between adjacent ones, and their overall distribution pattern, respectively. Each protrusion induces a pair of streamwsie vortices, producing low and high shear stresses at its center and side locations, respectively. These vortices also interact with those induced from adjacent protrusions. As a result, the drag is either increased or unchanged for all the cases considered. In some cases, the skin friction itself is reduced but total drag including the form drag on the protrusions is larger than that of a smooth surface. Since the shape of present protrusions is similar to that used by Sirovich and Karlsson [Nature 388, 753 (1997)] where V-shaped protrusions pointing upstream were considered, we perform another set of experiments following their study. However, we do not obtain any drag reduction even with random distribution of those V-shaped protrusion.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.109-115
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• 2006

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.

• KASI NEWSLETTER
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• s.44
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• pp.1-4
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• 2004

2004 별의 축제 개최/ 새로 발견된 5개의 소행성에 한국의 과학기술자 이름 헌정/ 제12회 천체사진공모전 당선작 선정 및 시상/ 충남첨단과학축전 참가/ FIMS이용, 세계최초 돛자리초신성 전체 영상관측/ "CFHT 사용자 모임 2004 및 천문학회 광학분과 모임" 개최/ 한국천문연구원-크리미아천문대 공동연구 협정 체결/ 식목행사/ 학회동정/ 파견 및 교육/ 직원동정/ 제37회 과학의 날 포상/ 해외과학기술인력 활용/ 채용안내/ 콜로키움/ 캐나다 Dominion Astrophysical Observatory를 다녀와서(I)

• The Inventors News
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• no.30
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• pp.3-4
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• 2005

`2004 대한민국 특허기술대전` 성황리 개최 - `2004 서울국제발명전시회` 성대히 열리다 - 과학기술자 위한 특허정보 활용전략 세미나 - 한$\cdot$중$\cdot$일 3국간 특허협력 가속화 - 상표권 분쟁 예방 위해 상표 이의신청제도 적극 활용 - 부산 동래구청 이춘기씨 `야광 쓰레기 카트` 특허 획득 - 대전 대신고교 `발명 콘텐츠 공모전` 대상 수상 - 특허청, 특허 권리회복제도 도입 - 전자업계 `특허 CEO 포럼` 돛 올렸다 - 에디슨 특허 기록 깬 일본인 발명왕 탄생

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.818-823
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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.