• 로봇학회논문지
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• 제8권1호
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• pp.51-57
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• 2013

Recently, the number of jellyfish has been rapidly grown because of the global warming, the increase of marine structures, pollution, and etc. The increased jellyfish is a threat to the marine ecosystem and induces a huge damage to fishery industries, seaside power plants, and beach industries. To overcome this problem, a manual jellyfish dissecting device and pump system for jellyfish removal have been developed by researchers. However, the systems need too many human operators and their benefit to cost is not so good. Thus, in this paper, the design, implementation, and experiments of autonomous jellyfish removal robot system, named JEROS, have been presented. The JEROS consists of an unmanned surface vehicle (USV), a device for jellyfish removal, an electrical control system, an autonomous navigation system, and a vision-based jellyfish detection system. The USV was designed as a twin hull-type ship, and a jellyfish removal device consists of a net for gathering jellyfish and a blades-equipped propeller for dissecting jellyfish. The autonomous navigation system starts by generating an efficient path for jellyfish removal when the location of jellyfish is received from a remote server or recognized by a vision system. The location of JEROS is estimated by IMU (Inertial Measurement Unit) and GPS, and jellyfish is eliminated while tracking the path. The performance of the vision-based jellyfish recognition, navigation, and jellyfish removal was demonstrated through field tests in the Masan and Jindong harbors in the southern coast of Korea.

• 한국수산과학회지
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• 제47권5호
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• pp.459-473
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• 2014

The recent mass appearances of jellyfish in Korea have caused economic and social damage, as they plague swimmers and fishermen. However, jellyfish have high economic and nutritional value, and contain low levels of calories and hydrolysates. Thus, jellyfish are a natural, healthy food that can improve high blood pressure, bronchitis, and a multitude of other diseases. Here, we present research on the ecology, classification, bloom, damage caused, food component characterization, and tissues of jellyfish, with the aim of facilitating further study. Research on use of jellyfish as salted products, and for collagen and qniumucin would also be valuable. A jellyfish body is classified into three parts: the body, termed the umbrella; the oral arm; and the tentacle. Jellyfish are planktonic marine members of a group of invertebrate animals comprising the classes Schypozoa (phylum Cnidaria) and Cuboza. In Korea in 2012, jellyfish damage resulted in decreases of annual catch and commercial value estimated at 177 and 141 billion won, respectively. Because concentrations of heavy metals are below the safety limits for seafood, dried jellyfish appear to be safe raw materials for food. The proximate compositions of Nemopilema nomurai and Aurelia aurita were 97.1% and 96.5% moisture, 0.9% and 1.2% crude proteins, undetected and 0.1% crude lipids, and 1.7% and 1.8% ash, respectively. According to their total contents of essential, total, and non-essential amino acids, jellyfish gonads were deemed good-quality protein. Because the major functional components of jellyfish are collagen and qniumucin, jellyfish can be used salted, or these components of healthy diets can be extracted from them. For more effective use of jellyfish, unit costs should be decreased and safety guaranteed. Additionally, dehydrators attached to conveyor belts should be developed. Since jellyfish can be used throughout the year, they should be listed in the Korean Food Standards Codex as a food source.

• 수산해양교육연구
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• 제26권3호
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• pp.587-596
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• 2014

The study aims at suggesting the direction of industrial utilization for harmful jellyfish which appears in large quantities in the Korean coastal areas. If the technology of industrial utilization for the jellyfish is developed, it will be possible to grow the industry to the export industry due to the mass appearance of jellyfish in Korean coastal areas. The industrial utilization of jellyfish should follow the direction of minimizing the damage by the jellyfish blooms and maximizing the resource recycling of the jellyfish. Therefore, Korea needs construction of infrastructure for the industrialization and promotion of R&D in order to activate the industrial utilization. Finally, the study suggested issues and tasks for promoting the industrial utilization of jellyfish as follows. First, Korea should stabilize the high quality raw material supply system. Second, mass processing technology should be developed for the industrial utilization of the jellyfish. Third, research and manual development should follow for the preparation of turning the jellyfish to the food. Fourth, extraction technology of useful non-food substance such as extracting collagen from jellyfish should be developed and accelerate the industrial utilization of non-food area.

• 수산해양교육연구
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• 제27권6호
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• pp.1755-1763
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• 2015

The objective of this study is to empirically analyze the relationship between sea temperature and jellyfish blooms. Ever since the 2000s, jellyfish population has been dramatically increased, which brought negative influence on the national health and the fisheries activities. Jellyfish blooms have been recognized as an effect of climate change, but there has been no empirical evidence to support such relationship. In this paper, the relationship between sea temperature and jellyfish blooms has been analyzed by using the regional jellyfish monitoring data and coastal stationary observing data of National Institute of Fisheries Science. Since the dependant variable carries left censoring issues, we used the panel tobit model. Our results indicate that there are statistically significant positive relationship between sea temperature and jellyfish blooms.

• 한국해양학회지:바다
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• 제17권1호
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• pp.25-31
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• 2012

기후변화, 수산자원 남획, 연안 간척 및 방조제 건설 등으로 인한 해양환경 변화는 해파리의 잦은 출현과 대량발생을 유발하고 있으며, 결과적으로 해양생태계 파괴, 수산업붕괴, 행락객 해파리 쏘임사고 발생 등 국가적 규모의 사회경제문제를 야기시키고 있다. 해파리로 인한 피해를 경험한 다수의 국가들은 해파리를 관리하기 위한 방법을 마련하는데 많은 투자를 하고 있을 뿐만 아니라, 더 나아가 해파리를 이용할 수 있는 방법을 모색하고 있다. 우리나라에서는 현재 해파리 대량발생을 막기 위한 생리 생태 연구와 해파리 구제를 중심으로 연구가 진행 중에 있다. 유럽 연합은 해파리 대량발생의 원인과 조절, 통합관리를 위한 연구를 수행중이며, 미국은 한 부처를 지정하여 수산자원 보전 및 보호를 목적으로 해파리를 관리하고 있다. 일본은 부처 및 연구기관의 지정으로 짧은 시간에 많은 분야에서 괄목할만한 성과를 거두었으며, 특히 해파리 이동과 대량발생 예측에 관하여 심도 있는 연구를 진행하고 있다. 본 연구는 이러한 국내외 연구방향을 비교하여 1) 통합연구시스템의 설치와 관리방안 마련, 2) 해파리에 대한 접근방식의 개선, 3) 적극적인 교육과 정보의 제공이라는 세 가지 정책 방향을 제시하였다. 본 연구 결과는 해파리뿐만 아니라 기타 유해해양생물의 정책적 대처 방안에도 기본적으로 필요한 대안이 될 수 있을 것으로 기대해 본다.

• 수산해양기술연구
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• 제58권1호
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• pp.19-31
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• 2022

Damages by jellyfish are occurring frequently around the world. Among them, accidents caused by jellyfish stings are serious enough to cause death. So we designed a jellyfish blocking net and analyzed its stability to prevent sting caused by jellyfish entering the beach. To this end, the dynamic behavior of the jellyfish blocking net according to the current speed (0.25-1.0 m/s) and the net type (50, 100 and 150 mm) on the upper part of the blocking net was modeled using the mass spring model. As a result of simulations for the model, the horizontal tension (horizontal component of the mooring tension) of the mooring line increased with the decrease in the mesh size on the upper part of the blocking net at all current speeds, but exceeded the holding force at high tides faster than 0.5 m/s and exceeded the holding force at all current speeds at low tide. Therefore, the jellyfish blocking nets showed poor stability overall. The depth of the float line had a little difference according to the upper mesh size and increased lineary proportional to the current speed. However, the float line sank too much to block the incoming jellyfish. These analysis results helped us find ways to improve the stability of the jellyfish blocking net, such as adjusting the length of the mooring line and improving the holding power. Therefore, it is expected that this technology will be applied us various underwater structures to discover the weaknesses of the structures and contribute to increasing the stability in the future.

• 대한원격탐사학회지
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• 제33권1호
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• pp.15-24
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• 2017

Jellyfish (cnidarian) are conspicuous in many marine ecosystems when in bloom. Despite their importance for the ecosystem structure and function, very few sampling programs are dedicated to sample jellyfish because they are patchily distributed and easily clogged plankton net. Although satellite remote sensing is an excellent observing tool for many phenomena in the ocean, their uses for monitoring jellyfish are not possible due to the coarse spatial resolutions. Hence, we developed the low altitude remote sensing platform to detect jellyfish in high resolutions, which allow us to monitor not only horizontal, but also vertical migration of them. Using low altitude remote sensing platform,we measured the jellyfish from the pier at the Chesapeake Biological Laboratory in Chesapeake Bay. The patterns observed included discrete patches, in rows that were aligned with waves that propagated from deeper regions, and aggregation around physical objects. The corresponding areas of exposed jellyfish on the sea surface were $0.1{\times}10^4pixel^2$, $0.3{\times}10^4pixel^2$, and $2.75{\times}10^4pixel^2$, respectively. Thus, the research result suggested that the migration of the jellyfish was related to the physical forcing in the sea surface.

• Ocean and Polar Research
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• 제37권4호
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• pp.287-293
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• 2015

A species of edible Scyphomedusae jellyfish has been used as food by the local people in Ganghwado, Korea since the 1990s. In order to identify this jellyfish, we collected specimens in Ganghwado during September 2013, and compared these specimens with original descriptions made by Kishinouye (1890). Mitochondrial cytochrome oxidase subunit 1 (CO1) sequences of these specimens were compared with those of Rhopilema esculentum retrieved from GenBank. Our specimens were also compared with jellyfish collected in China, previously confirmed as R. esculentum, based on morphological characters and DNA sequences. Using these two methods, the jellyfish specimens caught in Ganghwado were correctly identified as R. esculentum, a species new to Korean waters. This edible jellyfish has been named 'Gisusik-Yonghaepari' as Korean name.

• 로봇학회논문지
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• 제12권4호
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• pp.432-440
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• 2017

In this paper, we propose a jellyfish distribution recognition and monitoring system using a UAV (unmanned aerial vehicle). The UAV was designed to satisfy the requirements for flight in ocean environment. The target jellyfish, Aurelia aurita, is recognized through convolutional neural network and its distribution is calculated. The modified deep neural network architecture has been developed to have reliable recognition accuracy and fast operation speed. Recognition speed is about 400 times faster than GoogLeNet by using a lightweight network architecture. We also introduce the method for selecting candidates to be used as inputs to the proposed network. The recognition accuracy of the jellyfish is improved by removing the probability value of the meaningless class among the probability vectors of the evaluated input image and re-evaluating it by normalization. The jellyfish distribution is calculated based on the unit jellyfish image recognized. The distribution level is defined by using the novelty concept of the distribution map buffer.

• 기술사
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• 제43권1호
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• pp.46-49
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• 2010

Sea temperature rise by global warming, depletion of fishery resources and ocean pollution have caused unusual population explosion of the jellyfish, The blooming of jellyfish have brought social problem and economic damage, Therefore the interdisciplinary study of jellyfish by scientists and countermeasure are needed.