• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.49-62
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• 2015

As methods reducing damages by jellyfish which enter the coastal areas of Korea, attaching cutting devices to towing nets of otter trawls or pair trawls and/or using a canvas type of cutting nets of small fishing boats have been widely utilized. In order to reduce shut-down damages of power plants in coastal areas due to the mass influx of marine organisms including jellyfish, a possible improvement of the traveling water screen system and various jellyfish influx blocking devices were suggested in this study. The results could be utilized as an important index for reducing damages by jellyfish bloom which cause on a massive scale in summer in Korea.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.245-252
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• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.289-299
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• 2019

Various sizes of ROVs are being utilized in offshore industrial, scientific, and military applications all around the world. Because of innovative developments in science and technology, image acquisition devices such as sonar devices and cameras have been reduced in size and their performance has been improved. Thus, we can expect better accuracy and higher resolution even in the case of exploration using a small ROV. The purpose of this paper is to prepare a standard procedure for the identification of unidentified hazardous materials found during the National Oceanographic Survey. In this paper, we propose an IDEF (Integrated DEFinition) method modeling technique to identify unidentified targets using a small ROV. In accordance with the proposed procedure, an ROV survey was carried out on target No.16 with a four-ton-class fishing boat as a support vessel on September 18th of 2018 in the sea near Daebu Island. Unidentified targets, which were not known by the multi-beam data obtained from the ship, could be identified as concrete pipes by analyzing the HD camera and high-resolution sonar images acquired by the ROV. The whole proposed procedure could be verified, and the survey with the small ROV required about 10 days to identify the target in one place.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2549-2554
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• 2011

This paper describes on development of integrated interface and applications to support stable digital data communication service for small and midium sized crafts exploiting SSB modems and HF wireless sets. Firstly, integrated interface module between GPS (Global Positioning System) and communication devices was developed. Secondly, maritime map was implemented into a display terminal to provide location tracking service and voyage planning function. In addition, condition monitoring service of crafts and fishing report functions as well as alarm functions were developed to support secure fishery. Results of performance measure on developed application services shows that error rate was less than 3% and communication delay was shorter than 1 second when a message length was less than 1 Kbyte along with one-to-many communication type.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.100-101
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• 2012

According to growing the leisure boat market, safety-related and weather information have been required by different users with different electronic devices. NAVTEX messages transmitting worldwide from local stations are a kind of useful service, even for non mandatory carriage requirement vessel, such as small or fishing vessels. However, it is not easy for all users to recognize intuitively. This paper is to implement the NAVTEX message on tablet PC, indicating warning positions of message on Android-based google map.

• Journal of the Korean Society of Food Culture
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• v.13 no.5
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• pp.393-403
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• 1998

This study was conducted to investigate the contemporary dietary life of residence in Kyunggi province. People living in Kimpo, Yoju districts(farm villages), Kapyung districts (mountain villages) and Hwasung districts (fishing villages) were selected for this research as subjects from August S to 19,1997. The results of the survey are summarized as follows: 1. Cooked rice was a staple food. However nuddles and soojaebees(soup with dough flakes) was taken as lunch or snacks but Juk(rice guel) or Dduk(rice cake) was not treated as a meal. 2. Dishes were consisted with soup or chigae, kimchi and namul(seasoned vegetables), and fishes, meats, salted sea foods, dried fishes, jangacchi(dried seasoning radish) were also taken by sometimes. 3. Soy sauce, bean paste, red pepper bean paste were made by every home even if they were very busy. 4. Festival days such as New Year's Day, daeborum(the 15th day of January), chusok(mid-autumn festival), and kosaa(October ceremony) and dongee(one of 24 seasons by lunar calendar) are skipped oftenly and slowly forgotten by people. They do not celebrate Samgin-nal(the third day of March), Buddha's birthday(the 8th day of April by lunar calendar), danoh(the 5th day of May), yoodoo(the 15th day of June), chilsok(the 7th day of July), Jungyang(the 9th day of September) and the last day of the year either 5. Due to improved kitchen system, we couldn't see the old kitchen devices.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.449-461
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• 2023

The aim of this study was to conduct an ecosystem-based fishery risk assessment of tuna fisheries in the Western Indian Ocean. We selected gillnet, purse seine, hand line, baitboat, and longline fisheries as the target fisheries method, and selected longtail tuna (Thunnus tonggol), narrow-barred Spanish mackerel (Scomberomorus commerson), kawakawa (Euthynnus affinis), skipjack tuna (Katsuwonus pelamis), yellowfin tuna (T. albacares), bigeye tuna (T. obesus), albacore tuna (T. alalunga) and swordfish (Xiphias gladius) as the target species. The risk score for the size at the first capture in sustainability objective was high, especially, for the purse seine and baitboat fisheries using the fish aggregating devices (FADs). The risk score for the bycatch in the biodiversity objective was high for the gillnet fishery, and the gillnet fisheries using FADs showed high risks for the habitat quality objective due to the loss of the fishing gears. With regards to the socio-economic benefits objective, the risk score of the sales profits was low due to high sales of the tuna fisheries. The ecosystem risk score in the Western Indian Ocean was estimated to be moderate, although management is required for some of the indicators that have high-risk scores.

• Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.61-66
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• 2020

Since the ocean accounts for 70.8 percent of the earth's surface, the success of IoT technology in the marine industry is to collect information from devices placed in a wider range. LPWA is a feature with a wide range of communication and is very suitable for deployment in the ocean. In this paper, the real-sea performance distance experiment was carried out based on Private LoRa, a key technology for executing the electronic phrase real-name system. A private LoRa module based on sx1276 was developed, and Gateway was developed to transfer data received by private LoRa to the server using SKT Cat. M1. After installing gateways at 599 meters above sea level and experimenting with data transmission and reception at 25 km, 40 km and 60 km, we were able to see that the communication success rate was obtained to be 96.1%. 97.1% and 96.2% respectively.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.243-246
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• 2008

ISM(Industrial, Scientific, Medical)대역은 비면허 대역으로 일정한 출력 규제만 지키면 자유롭게 사용할 수 있다는 장점으로 인하여 육상 통신뿐만 아니라 해상 통신 영역까지 그 사용량이 급증하고 있다. 이에 어선 내에서 사용하는 전파응용설비 및 ISM대역을 사용하는 소출력무선기기 등과의 전파간섭 문제는 시스템의 안정성을 열화시킬 수 있는 요인이 되며, 선박상황을 고려하면 안전성과 직결되므로, 간과되지 말아야 한다. 따라서 ISM대역에서 사용되거나 사용될 무선설비의 간섭확률 분석은 필수적이다. 본 논문에서는 Monte-Carlo 방식을 기반으로 하는 SEAMCAT를 이용하여 거리 및 밀도에 따른 간섭 시나리오와 전파 간섭 simulation methodology를 제안하였으며, 해상에서 환경을 가정하여 다른 전파간섭을 배제하였다. 제안된 시나리오를 적용하여 13.56MHz ISM 대역의 거리 시나리오 시뮬레이션 결과 RFID는 4.7m 이상, 모형기기는 2.7m 이상의 동종 기기간 이격거리를 가질 경우 간섭 영향이 양호하였다. 밀도 시나리오 시뮬레이션 결과 RFID(${V_r}$)를 중심으로 간섭 영향권에 RFID와 모형기기가 각각 2개 이하, 모형기기(${V_r}$)를 중심으로 간섭 영향권에 모형기기 2개 이하, RFID 1개 이하로 사용될 경우 통신환경이 양호함을 알 수 있었다. 제안된 간섭 시나리오 및 시뮬레이션 기법은 향후 ISM대역의 규제 정책 및 간섭확률 분석에 기여할 것으로 기대된다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.276-280
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• 2016

This study investigated luring distributions by water layer of common squid which were targeted by angling fishing vessels equipped with LED and metal-halide lamps using a scientific echosounder with a 120 kHz frequency in order to develop energy-effective underwater fish aggregation devices. In the analysis, angles of a transducer were changed from $0^{\circ}$ to $45^{\circ}$ and were rotated every $10^{\circ}$ horizontally. It was shown that common squid were densely distributed from the surface to 40 m and they were also distributed in directions of $10^{\circ}{\sim}+30^{\circ}$, $-30^{\circ}{\sim}-60^{\circ}$, and $-120^{\circ}{\sim}-130^{\circ}$with the head of vessel as the center. Comparative results of angles of transducer on acoustical densities of common squid distributing in 21~40 m water depth showed an average $101.8m^2/nm^2$ in vertical direction of $0^{\circ}$, $12.3m^2/nm^2$ in angle of $30^{\circ}$, and $42.4m^2/nm^2$ in angle of $45^{\circ}$, respectively. It implied that more considerations on acoustic scattering strength by incidence angle direction of the transducer and swimming oriental angle direction of common squid would be required.