• 한국수산과학회지
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• 제52권3호
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• pp.288-297
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• 2019

This study conducted a survey using a sampling inspection method and acoustic technique for continuous monitoring of useful organisms and non-commercial fish species distributed in the water of Gwangyang Bay, and evaluated the marine resources. In June, 2018, 38 species were caught in the shrimp beam trawl, comprising 3,594 marine organisms with a total weight was 65,415.3g. The acoustic survey showed that the nautical area scattering coefficient (NASC; $m^2/n.mile^2$) for the waters of Gwangyang Bay was highest in Transect 15 ($1,655.5m^2/n.mile^2$) and lowest in Transect 1 ($1.3m^2/n.mile^2$). The biomass was estimated to be 2,634.9 tons in the acoustic survey. This indicates that the acoustic survey method detected more fish shoals than the sampling inspection method.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.483-486
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• 2006

The study describes the monitoring of the Bay of Bengal as a ballast water exchangeable sea using MODIS/Aqua-derived diffuse attenuation coefficient (K(490)) synchronized with in situ ballast water sampling and analysis along the LNG carrier's route between Japan and Qatar from 2002 to 2005. Based on the relationship between K(490) and corresponding in situ plankton cell densities, the Bay of Bengal is recognized as a ballast water exchangeable sea to meet the regulation of ballast water performance standard of International Maritime Organization (IMO). Furthermore the Bay of Bengal with more than 200m depth and more than 200 nautical mile distance from shore is extracted based on the regulation of ballast water exchange area of IMO. However, an anomalously high K(490) area is found off the coast of Sri Lanka during the northeast monsoon in 2005, which corresponds higher cell densities than the criterion set by the regulation of IMO. The phenomenon of high cell density in the Bay of Bengal seems to be related with the phytoplankton bloom during the northeast monsoon. Seasonal and annual variability of phytoplankton bloom will be investigated to establish an early routing system for avoiding the high cell density area in advance.

• International Journal of Computer Science & Network Security
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• 제22권9호
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• pp.271-279
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• 2022

In the discipline of design science, the integration of cognitive, semantic, and affective elements is crucial in the conception and development of a product. Affective components in IT artefacts have attracted researchers' attention, but little attention has been given to Geographic Information Systems (GIS). This research was conducted to identify emotions in web-based GIS, and determine design influences on the emotions using Kansei engineering (KE). In the evaluation procedure, ten web-based GIS were used as specimens, and 20 Kansei words were used as emotional descriptors in the Kansei checklist. 50 participants were asked to rate their emotional responses towards the specimens on the Kansei checklist. Principal Component Analysis was used to discover the semantic structure of Kansei, in which dynamism and spaciousness were identified. Significant Kansei concepts were identified using Factor Analysis, in which dynamic & well-organized, refreshing, spacious, professional, and nautical-look were identified. Partial Least Square analysis has assisted the research in discovering the significant design influence to the Kansei. These findings provide designers and other stakeholders with valuable knowledge for strategizing future web-based GIS designs that incorporate user emotions.

• 한국수산과학회지
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• 제47권6호
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• pp.1055-1062
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• 2014

Hydroacoustic surveys were conducted for spatio-temporal distribution and size estimation of fish in the Yongdam reservoir, Korea, from April to July 2014. Acoustic data were collected along acoustic transects using a 120 kHz scientific echosounder. The received acoustic data were the in situ acoustic target strength (dB) and nautical area scattering coefficient ($m^2/mile^2$). Data on fish behavioral patterns and size were collected using a DIDSON acoustic camera at stationary stations. Fish were mainly distributed in the center channel and close to the outer Yongdam reservoir. Acoustic density of fish in the summer season were higher than in the spring season. The seasonal vertical distribution pattern of fish aggregations may be strongly related to the vertical temperature structure. The size distribution of fish obtained from an acoustic camera correlated well with the acoustic size of fish from an echosounder.

• 해양환경안전학회지
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• 제23권1호
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• pp.56-66
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• 2017

본 연구에서는 상선과 어선의 해기사, 해군의 함정장교 양성기관의 해기교육 시스템을 비교분석 함으로써 해양력 확보를 위한 해기교육 상황을 파악하였다. 분석결과 상선의 해기사 양성과정을 제외하고는 선박운영에 관한 교육과정이 상대적으로 낮은 비중을 차지하고 있었다. 선박운영에 필수적인 해기교육의 강화는 해양력 확보에 필수적이지만 인력공급이 어려운 선원직의 특수성이 교육과정에 반영된 것으로 보인다. 우수한 선원의 확보와 해기교육 문제를 해결하기 위해서는 국가차원의 관심과 지원방안이 마련되어야 할 것이다.

• Journal of Astronomy and Space Sciences
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• 제21권4호
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• pp.505-528
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• 2004

[ ${\ll}$삼국사기${\gg},\;{\ll}$고려사${\gg},\;{\ll}$조선왕조실록${\gg},\;{\ll}$승정원일기${\gg}$ ]에 나오는 천문 관측 기록 가운데 특히 달가림(lunar occultation) 기록을 분석하여 당시의 시간제도와 하루의 시작점을 알아냈다. 특히, 조선시대에는 일식이나 월식을 계산할 때는 백각법(百刻法)과 12진각법(十二辰刻法)이 사용되었고 하루의 시작점은 자정이었으나, 일상생활과 특히 천문관측에서는 경점법(更點法)이 사용되었는데, 하루의 시작점은, 최소한 고려시대부터는, 해 뜰 무렵임을 확인하였다. 또한 전통적으로 동아시아 문화권에서 사용한 혼명(昏明)의 시간은 현대의 항해박명(nautical twilight)을 뜻함을 알아냈다. 우리의 결과는 현재 일상생활의 시간관념이 옛날 시간제도에서 비롯되었음을 말해주며, 농경사회에서 해의 뜨고 짐에 따라 일상생활이 정해지고 또한 천문 관측상 편리하기 때문에 경점법을 쓴 것이라고 해석된다. 우리의 연구 결과는 앞으로 고대 천문 관측 기록의 시간을 정확하게 미루어 계산하고, 그것을 현대 천문학적 자료로 사용하는데 유용할 것이다.

• 한국수산과학회지
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• 제55권6호
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• pp.938-945
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• 2022

National Institute of Fisheries Science conducted a total of 39 sighting surveys for marine mammals over 624 sighting days that covered 20,771 nautical miles in Korean waters during 2011-2020. Marine mammals were detected when 83.9% of the marine environment was less than or equal to three on the Beaufort wind scale. Thirteen species of marine mammals were identified, including two species of pinniped, with a majority of cetacean species. Frequently found species were narrow-ridged finless porpoise, followed by common dolphin, minke whale, Dall's porpoise, and Pacific white-sided dolphin. Narrow-ridged finless porpoises and minke whales were located in and offshore around the Korean peninsula, common and Pacific white-sided dolphins were exclusively found in the East Sea for most seasons. The other marine mammals were spotted in some seas and for limited durations.

• 한국수산과학회지
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• 제50권4호
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• pp.421-428
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• 2017

The spatial distribution and abundance of fish species was estimate near Dok-do, East Sea of Korea by conducting midwater trawl survey with hydroacoustic method. Acoustic and midwater trawl data were collected onboard the R/V Tamgu 21 during 7-8 March 2016. Acoustic data were collected at the frequencies of 38 and 120 kHz and converted to nautical area scattering strength ($m^2/nmile^2$). Species are distributed mainly over an extent of 30-55 m, generally around southwest of Dok-do; the squid Watasenia scintillans was the dominant species found. The length-weight function and target strength of squid and other fishes were used to estimate the W. scintillans stock at 2499.1 tons and other fish at 43.8 tons during the winter season. The hydroacoustic method offers an approach for the determination of the biomass and vertical and spatial distributions of species aggregating near Dok-do, East Sea of Korea.

• 한국항해학회지
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• 제22권1호
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• pp.63-77
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• 1998

It is one of the most important factors Seafarers Ducation Quality Assurance and Management in Higher Maritime Educational Institution. The educational process and result of Higher Maritime Educational Institution should be evaluated according to the 1995 Amendments to the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers(STCW), 1978. Actually above-mentioned evaluation is deemed to make foundation in order to enhance the efficiency of shipboard education by surveying the satisfaction of shipboard training for nautical part cadets by the group. In this paper, we carried out the questionnaire survey to study satisfactory value and the reason of dissatisfaction of 113 cadets being trained on board the Training Ship in Maritime College of Korea Maritime University(K. M. U.). The results were calculated by frequency and percentage ; the significance of difference among Department groups like Maritime Transportation Science, Maritime Police and Ship Operating Systems Engineering was analysed by $X^2$ inspection. The major results of above analysis were as follows : First training chance for dadets was very little for being overflowed on board the training ship of the K. M. U. Second, special type of Training Ship HANBADA and HANNARA made the adaptability to merchant vessel's handling restricted. Third, cadets could not manage ratings directly, therefore the education in regard to seafaring management was limited to the theoretical instruction which leads to the low level of satisfaction. And lastly, low value of satisfaction for Drydocking Education in Shipyard was caused by cadet's leaving the Training Ship on account of the safety problems including ship and cadets.

• 한국수산과학회지
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• 제55권2호
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• pp.207-217
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• 2022

The accurate calibration of broadband echo sounders is essential for providing high quality acoustic information for fisheries applications. The increased range resolution of broadband echo sounder systems improves the detection and characterization of targets near boundaries, such as fish near the seabed. Most echo sounder systems are calibrated using tungsten-carbide (WC) spheres. For accurate calibration, it is necessary to select WC spheres of optimized diameters used frequently to calibrate echo sounder systems. For these purposes, the measured and simulated target strength (TS) data for seven WC spheres of different sizes were compared across a bandwidth of 100-200 kHz. The frequency-dependent TS pattern for the specular wave measured from two WC spheres using the fractional Fourier transform was also estimated and analyzed. Comparative results are presented for all the spheres and the best average precision of 0.15 dB was obtained for the 22 mm WC sphere.