• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.2
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• pp.71-75
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• 1982

The feeding sounds of three fishes, Lateolabrax japonicus, stephanolepis cirrhifer and Fugu vermicularis were recorded in the tank, and the frequency and the sound pressure level were analyzed. The recorded sounds were emitted again into the tank and the response of fishes were observed. The results obtained are summarized as follows: 1) The frequency and the sound pressure level of the feeding sound of Lateolabrax japonicus, Stephanolepis cirrhifer, and Fugu vermicularis are 80~350 Hz and 250~500 Hz, and 101~103 dB, 106~115 dB and 102~112dB. 2) It was most effective to increase the sound pressure level as much as dB that make the fishes respond positive reaction to the feeding sound. 3) Lateolabrax japonicus and stephanolepis cirrhifer showed positive response and Fugu vermicularis showed little to the emitted feeding sound. 4) The fishes showed positive response to the sound until 5 minutes and then showed negative response, as the sound emitting succeed 10 minutes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.195-201
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• 2000

This paper discusses methods for the stable bottom detection and the optimum bottom offset which enable to separate the fish echoes from the bottom echoes with echo integration of demersal fish. In preprocessing of the echo signal, the bottom detection has to be done stably against the fluctuation of echo level and the bottom offset has to be set to a minimum height such that near bottom fish echoes are included Two methods of bottom detection, namely echo level threshold method and maximum echo slope method were compared and analyzed. The echo level method works well if the ideal threshold level was given but it sometimes misses the bottom because of the fluctuation of the echo. Another method to detect the bottom which uses maximum echo slope indicates the simple and stable bottom detection. In addition, the bottom offset has to be set near to the bottom but not to include the bottom echo. Optimum bottom offset should be set a few samples before the detected bottom echo which relates the beginning of pulse shape and acoustic beam pattern to the bottom feature.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.739-746
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• 2020

The fourth industrial revolution introduced at world economic forum in 2016 has had huge effects on tourism industries as well as the change of core technologies in ICT such as big data, IoT, etc, This paper proposes the methods to propel tourism of Yoesu city through big data analysis and questionnaires. Sensitive words and positive-negative trend are extracted by Social Metrics and the keywords for Yeosu tour trends are extracted and analyzed by Naver datalab, and the results are visualized by R language. And frequency, difference, factor, covariance and regression analysis in SPSS are executed for the questionnaires for 493 visitors who traveled in Yeosu city. Sentiment analysis for Yeosu tour and maritime cable car shows that positive effect is much more than negative one. The analyses for questionnaires in SPSS show that Yeosu area is statistically significant to tour satisfaction index and tour revitalization for Yeosu, and favorite sightseeing places and searching electronic devices for age groups are different. The sightseeing places such as a maritime park with soft contents that give joyfulness and healing to tourists are highly attracted in both the big data and questionnaires analysis.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.24-34
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• 2021

Many countries have established and implemented marine ecosystem management plans to solve various problems arising from excessive development and use of marine and coastal areas. In this study, network analysis was applied to compare and understand marine ecosystem management's direction and characteristics in Korea and other maritime countries. The results showed that the words 'strengthen,' 'promote,' 'improve,' and 'establish' were the keywords used a lot in domestic and foreign marine ecosystem management plans. Establishing a foundation for marine ecosystem management, establishing international cooperation and partnerships, and strengthening climate change adaptation was commonly included. However, there were some differences in detailed management plans. In foreign countries, it aims to present management measures for certain species and improve the existing institutional foundation. Still, in Korea, it aims to strengthen the comprehensive management of marine life and establish an institutional foundation for marine ecosystems. This study is expected to help understand the direction of domestic and overseas marine ecosystem management and establish a domestic marine ecosystem management plan in the future.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.1-7
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• 2022

A larva of the deep-sea angler fish, Himantolophus groenlandicus (2.2 mm BL), identified based on the complete mitochondrial DNA sequence, was collected at the surface of the western North Pacific. The postflexion stage larva had a round body, small teeth, incipient dorsal fin rays, eyes slightly recessed in the lower part, and melanophores on the gills and parietal and dorsal regions. These morphological features differ from a description of a larva reported as the same species with similar size (2.1 mm BL). The genetic and morphological information of our specimen should be useful for identifying larval H. groenlandicus.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.489-490
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• 2021

본 연구에서는 해양사고 처리 중 발생하는 인명사고 발생률을 감소시키고, 효율적으로 양식장을 관리하는 것을 전제로 카메라와 센서를 다기능 해양탐사 로봇에 적용하고자 한다. 현재의 양식장 관리 시스템은 수온 체크만 할 수 있게 되어있다. 이러한 시스템은 양식어에게 적합한 환경을 제공해주기 쉽지 않다. 본 논문은 이러한 문제점들을 개선하기 위해 기존의 해양 처리시스템과 양식 시스템 대신 카메라와 수온 센서, pH 농도 센서, 초음파 거리 센서, DC 모터, 블루투스 모듈을 적용한 다기능 해양탐사 로봇 기술을 제안한다. 기존의 시스템과는 다르게 안전하고 효율적으로 환경을 분석하고, 제어할 수 있다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.160-172
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• 2020

To understand on-site feeding traits of Noctiluca scintillans with unprecedented high abundances around Dokdo in spring, 2014, the composition and abundance of food items in the digestive vacuole of the species were analyzed. Abundances of N. scintillans ranged from 4,328~17,791 inds.m^-3 around Dokdo during the study. The incidence of preyed items in the vacuole of N. scintillans ranged by averaged 32% (24~50%) in the surface waters around Dokdo. Diverse preyed items consisted of fecal pellet, protozoans, pollen, diatoms, dinoflagellates, copepods and ichtyoplankton, while fecal pellets were dominantly fed by N. scintillans (43%) and next by protozoans (19%), pollen (18%), diatoms (7%) and dinoflagellates (4%). Fecal pellet, protozoans and pollen were relatively preferred by N. scintillans compared to diatoms, dinoflagellates and ichtyoplankton based on the incidence in the food vacuoles. Present results indicated that high abundance of N. scintillans found around Dokdo was likely associated with non-phytoplankton items rather than previously well-known diatoms as prey during the study.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.186-200
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• 2022

In order to understand the species composition and distribution characteristics of larval assemblages in the East Sea, Korea, larvae were collected at 13 stations every other month from February to December 2018. Fish larvae were identified through DNA barcoding along with morphological methods, and as the result, a total of 104 taxonomic groups appeared during the survey. Among these, Engraulis japonicus, which accounted for 76.2% of the total population, was the most dominant species, followed by Maurolicus japonicus, which accounted for 15.0%. In addition, Ammodytes personatus, Champsodon snyderi, Scomber japonicus and Echelus uropterus appeared more frequently than other taxa. The above six species accounted for 93.2% of the total catch. The number of taxa and the amount of larvae collected in the survey area were higher during the high water temperature periods (June to October) than during the low water temperature periods (February, April and December). Analysis of similarity (ANOSIM) showed a statistically significant difference in monthly larval assemblages. The results of the canonical correspondence analysis (CCA) show that the distributions of larval community were mainly affected by sea surface temperature during low water temperature periods, and various environmental factors such as salinity, dry weight of zooplankton, and the concentrations of nutrients during high water temperature periods.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.112-113
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• 2002

생선회의 품질을 결정하는 중요한 요인은 씹힘성(촉감)으로, 생선회의 단단함(toughness)은 어종, 원료어의 신선도, 조리 후의 저장조건 및 치사방법 등에 따라 달라진다. 어육의 단단함은 생선회의 맛에 직결되어 육질이 단단한 어종일수록 양질의 횟감으로 선호되기 때문에 육질을 개선하기 위한 일련의 연구가 진행되고 있다. 즉, 운동사육에 의하여 근육의 장력을 발생시키는 방법, 사육수온을 변화시키는 방법, 한약재를 사료에 투여하여 육중의 결합조직의 함량을 증대시키는 방법 및 절식사육에 의하여 양식어의 육질을 개선하는 방법 등으로, 이 방법들은 어육의 actomyosin toughness나 background toughness를 향상시키는 방법들이다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.265-266
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• 2000

자주복, Takifugu rubripes은 경골어류 복어목 참복과에 속하고, 우리 나라 전 연안 및 일본 훗카이도 이남, 중국 등지에 분포하며 전장 70 cm이상까지 성장하는 대형어이다(Abe, 1949). 어류는 자어기에 내부영양에서 외부영양으로 영양원이 전환되는 초기생활사에 있어 소화 기관계의 변화가 일어나고, 치어기의 생장과 생존에 크게 영향을 미친다고 제시하고 있다(Lee, 1988). 이 연구는 소화흡수와 직접 관련된 자주복 부화 자·치어의 각 성장단계에 따른 소화 기관의 형태적 기능적 분화과정을 조직학적으로 관찰하여, 종묘생산 과정에서의 초기 대량 폐사를 줄이고, 적절한 먹이 투여시기에 의한 보다 나은 성장률을 얻는데 중요한 기초자료를 제공하고자 한다. (중략)