• 전자공학회논문지
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• 제49권11호
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• pp.110-117
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• 2012

내수면 및 연근해에서 수질 오염 감시, 수중 생태 관찰, 수중 침입 감지 등을 효과적으로 수행하는 시스템이 요구됨에 따라 근거리 수중 음파 통신을 수행하는 음향 모뎀에 대한 관심도 증대되고 있다. 얕은 수심에서는 음파의 수중 전달 과정에서 발생하는 확산, 흡수, 반사, 산란 등에 의해 채널 해석이 용이하지 않으며 음향 모뎀의 개발 사례 및 성능이 매우 제한적이다. 또한, 얕은 수심에서 수중 음파 통신 시스템을 구성할 경우 고정형 수중 노드 및 이동형 수중 이동체에 탑재되는 수중 모뎀의 크기에 대한 제약이 존재한다. 본 논문에서는 수중 채널에서 음파의 전송 중 발생하는 손실에 대해 고찰하고, 고정형 및 이동형 근거리 수중 음파 통신에 적합한 고효율 초소형 음향 모뎀을 설계 구현한다. 개발한 수중 음향 모뎀을 활용하여 최대 500 미터, 2 kbps의 전송속도로 수심이 얕은 호수에서 실증 실험을 실시함으로써 적용 가능성을 검증한다.

• Ocean and Polar Research
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• 제31권1호
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• pp.97-110
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• 2009

Two of the most important topics of the 21st century are ensuring harmony between man and his environment and the emerging long-tail economy in which niche markets are becoming increasingly more important. Since the Industrial Revolution in 17th century, human beings have increasingly exploited the world's natural capital, such as the natural environment and its ecosystems. Now the world is facing limits to sustainable economic growth because of limits to this natural capital. Thus, most countries are beginning to adopt a new development paradigm, the so-called"Green Development Paradigm" which pursues environmental conservation in parallel with economic growth. Recently, the Korean government announced an ambitious national policy of Low Carbon & Green Growth for the next six decades. This is an important step that transforms the existing national policy into a new future-oriented one. The fisheries sector in particular has great potential for making a substantial contribution to this national policy initiative. For example, the ocean itself with its sea plants and phytoplankton has an enormous capacity for fixing carbon, and its vast areas of tidal flats have a tremendous potential for cleaning up pollutants from both the sea and the land. Furthermore, the fishing industry has great potential for the development of fuel-saving biodegradable technologies, and a long-tail economy based on digital technologies can do much to promote the production and consumption of green goods and services derived from the oceans and the fisheries. In order for this potential to be realized, the fisheries authority needs to develop a new green-growth strategy that is practical and widely supported by fishing communities and the markets, taking into account the need for greenhouse gas reduction, conservation of the ocean environment and ecosystems, an improved system for seafood safety, the establishment of strengthened MCS (monitoring control surveillance) system, and the development of coastal ecotourism. In addition, fisheries green policies need to be implemented through a well-organized system of government aids, regulations and compensation, and spontaneous (voluntary) orders in fishing communities should be promoted to encourage far more responsible fisheries.

• Ocean and Polar Research
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• 제25권3호
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• pp.331-345
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• 2003

The fishing ground surrounding Wangdol-cho is not only overexploited by the littering of dilapidated fishing net and equipment, but also by fishermen's overfishing, surpassing optimum fisheries resources. In addition, increasing fishing efforts (number of fishing vessel and fishing net, etc) contribute to the deterioration of fishing ground, and it is urgently required that schemes to tackle the problems should be taken. To effectively address the problems as such, this paper aims to propose sustainable utilization and management scheme of fishing ground through classification of fishing ground surrounding Wangdol-cho as one area which is less than 50m deep, measuring $13.66km^2$ and the other, permission fishing area of Gill Net fishery, measuring $347.23km^2$. The analysis shows that, for the water area less than 50m deep, implementation from a short-term perspective includes autonomous management fishery by gill net and trap fishery. For the permission fishing area of Gill Net fishery, implementation includes limit on fishing period, real name system of fishing equipment and limit on fishing equipment. Implementation from a medium and long-term perspective includes limit on scuba diving, designation of underwater sightseeing zone, sea farming, facilities of surveillance, adoption of approval system for the permission fishing area of Gill Net fishery and introduction of report system for fishing.

• 수산해양기술연구
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• 제43권4호
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• pp.347-354
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• 2007

This paper describes on the real-time monitoring of net setting and hauling process for fishing operations of Danish seine vessels in the southern waters of Korea as an application of a PC based ECDIS system. Tracking of fishing process was performed for the large scale Danish seine vessel of G/T 90 and 350 PS class using the fishing gear which the length of net, ground rope, head rope and sweep line including warp in both sides were 86m, 104m, 118m and 3,200m, respectively. Tracking information for net setting and hauling process was continuously recorded for 23 fishing operations performed on November and December, 2003. All measurement data, such as trawl position, heading, towing course and past track which was individually time stamped during data acquisition, was processed in real time on the ECDIS and displayed simultaneously on the ENC chart. The results indicated that after the separation of a marker buoy from Danish seiner, the averaged running speed of vessel and the averaged setting period while shooting the seine on the course of diamond shape to surround the fish school in the 23 fishing operations were 8.3 knots and 13.1 minutes, respectively. And with the maker buoy taken on board, the averaged running speed of vessel and the averaged towing period while closing the seine on the straight route was 1.0 knots and 47.0 minutes, respectively. After the closing stage of hand rope, the hand rope was towed by the averaged speed of 2.2 knots during the 13.0 minutes. The average area for route of diamond shape swept by sweep lines of the seine in 23 fishing grounds was $709,951.6m^2$. Further investigation is also planed to provide more quantitative tracking information and to achieve more effective surveillance and control of Danish seine vessels in EEZ fishing grounds.

• 한국항해학회지
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• 제22권2호
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• pp.13-22
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• 1998

선재용 자동식별시스템(AIS)은 21세기에 선박식별, 감시, 통신에 사용하기 위한 중요한 해상장비가 될 것 이며, 현재 여러 선진국에서 개발중에 있다. 본 논문에서는 AIS의 기술적인 방법을 제시하고자 한다. AIS의 주요 부분은 방송트랜스폰더(broadcast transponder)이고 핵심기술은 STDMA(self-organized Time Division Multiple Access)라 불리는 고용량의 VHF 라디오 데이터링크(radio data link)이다. 해상 VHF채널로 자신의 위치와 신분(identities)을 자동적이고 주기적으로 방송하게 될 AIS가 설치된 선박들은 선상이나 VTS 센터에 있는 ECDIC의 서면에 표시가 될 것이다. AIS는 방송서비스뿐만 아니라 일대일(point topoint) 통신 서비스를 지원하게 될 것이다. 본 논문에서는 STDMA의 방안 뿐만 아니라 AIS의 구성과 동작원리 그리고 기능을 설명하고자한다. 이외에 IMO에서의 AIS에 관한 표준화 작업을 본 논문에 소개하고자 한다.

• 한국정보통신학회논문지
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• 제22권4호
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• pp.676-682
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• 2018

무선 센서 네트워크에서 해양 수색 및 구조를 목적으로 노드의 소모 에너지를 최소화하기 위한 최적화 알고리즘을 제안한다. 해양 환경에서 수색 및 구조작업은 감시하는 측에서 주로 이루어지며, 구조되는 측에서는 수동적으로 기다려야 한다. 이에 반해 자가 구성 이 가능한 무선 센서 네트워크는 해양 수색 및 구조작업에서 능동적으로 구조 신호를 보낼 수 있는 시스템을 구축할 수 있다. 본 논문에서는 많은 수의 노드가 배치된 네트워크에서 노드의 소모 에너지를 최소화하기 위하여 시뮬레이티드 어닐링 알고리즘을 제안한다. 네트워크에서 노드의 밀도가 높으면 일반적으로 알고리즘 계산양이 급격히 늘어난다. 따라서 제안된 알고리즘은 적정한 실행 시간 내에 최적의 결과를 찾기 위해 새로운 이웃해 생성 동작을 제안하고 알고리즘의 효율성을 높인다. 제안된 알고리즘은 노드의 소모 에너지와 알고리즘 실행시간 면에서 성능 평가를 하였으며, 성능 평가 결과에서 기존의 방식에 비해 성능이 우수하였다.

• 대한원격탐사학회지
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• 제34권6_3호
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• pp.1311-1317
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• 2018

위성개발의 궁극적인 목적은 위성으로부터 획득되는 정보의 활용에 있다. 따라서 국가 차원의 위성개발 프로그램은 하드웨어 개발뿐만 아니라 정보 활용을 위한 인프라 구축 및 활용기술 개발도 포함하여야 한다. 지금까지 우리나라는 다양한 위성을 개발하여 기상 및 해양 감시를 비롯하여 각종 재해재난 등에 있어 매우 유용하게 활용해 왔다. 특히 다목적실용위성 영상은 높은 공간해상도를 바탕으로 농업, 산림분야를 비롯하여 해양 분야까지 폭 넓게 활용되어 왔으며, 최근에는 정밀 지도제작 및 변화탐지 등과 관련된 연구에 많이 이용되고 있다. 본 특별호는 최근 다목적실용위성 광학 및 레이더 영상을 활용하여 수행된 다양한 연구사례에 대해서 소개함과 동시에 관련 위성영상 활용기술을 공공부문으로 전파시키는데 목적이 있다.

• Fisheries and Aquatic Sciences
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• 제26권10호
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• pp.617-627
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• 2023

Harvest control rules have been recently developed for some fisheries in Indonesia, including grouper fisheries, and are expected to reverse the trend of declining stocks. One of the proposed options of the harvest control rules is to implement the catch size limit. The catch size limit approach, however, is challenging, unless it is supported also with strong fisheries surveillance, law enforcement, and innovation. The catch size limit approach can be done by implementing changes in fishing methods and gear, including the application of different hook sizes in the hook and line fishing gear. This study examines the impact of different hook sizes on the length at first capture (Lc) and on the bell-shaped maximum selectivity using various selectivity models of the two targeted grouper species (Plectropomus leopardus and Plectropomus maculatus) in the Saleh bay, West Nusa Tenggara, Indonesia. We found that increasing hook size influences the grouper's catch size, increasing the Lc and the bell-shaped maximum selectivity of both species. Based on our findings, hook size can be used as one of the practical tools for grouper management measures, as part of harvest control rules to improve grouper stock in Indonesia.

• 한국항해학회지
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• 제21권2호
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• pp.47-58
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• 1997

The purpose of this study is to find out the impacts of VTS on the marine safety and users' opinion on the VTS which have been being operated in the port of Pohang for the last 3 years and is to suggest a guideline to the successful operation of VTS in the future. This study is based upon the questionnaire survey and the respondents include 236 masters/mates of merchant vessels who have visited the port of Pohang and 6 pilots who have been working in the port. From the questionnaire results, this study notes the following conclusions related to the VTS operations. (1) A few of the respondents (mainly foreigners) do not understand the entering procedure of the port and the fundamental concept of VTS. Accordingly, the more active VTS services have to be provided for the mariners. (2) It was found that themost dangerous factors in tehvicinity of the port were the floating materials, fishing nets, andillegal fishing activities inthe fairway. Therefore, the proper surveillance, stricter enforcement of Acts and the instructive education for the fishermen are required to avoid the risks. (3) A majority of the respondents agreed the VTS has contributed to the safety of vessel traffic, and they pointed out ' the assiatances in reduced visibililty conditions' is the most important task of VTS. The amount of 75.6% of the respondents answered that they have experienced the assistance from VTS more than 1 time since the system was established in the port of Pohang . Also 44.2% of the respondents considered they were able to avoid marine casualties such as collision, ramming or agrounding with the VTS assistances. (4) 49.2% of the respondents preferred the passive information services , while, 38.8% of them preferred the positive control advices in the case of encountering any potential risks. VTS iperators have to consider seriously when they provide the positive control advices of ship's course and speed. (5) A majority of the respondents confirmed that the prot and its approaches is suitable for the VTS coverge . To extend the service areas of the VTS and to improve radar detecting ability, the use of radar transponders are seen as the ideal method. (6) A minority of the respondents pointed out 'the improper orders or recommendatinos caused by the poor decision making' firstly, ' the language problem(sea-speaking in English)' secondly, as the deficiency of personal qualification. It seems, therefore, theat the personal efforts of the operators and systematic training programmes for them are necessary to solve the problems.

• 한국어병학회지
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• 제21권3호
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• pp.259-270
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• 2008

Disease surveillance was performed to monitor the prevalence of fish pathogens in wild marine fish caught in coastal offshore water in Korea. A total of 333 of fish samples were collected at set net or fish market at landing port in Pohang (East Sea), Taean (Western Sea), Goseong and Tongyeong (Southern Sea) and 21 species of pathogens causing clinical infections to farmed fish were investigated. The detection rates of fish pathogens from Mugili formes, Tetraodontiformes, Pleuroneciformes, Sorpaeniformes, erciformes and Clupeiformes were 90.9, 61.1, 47.6, 43.6, 37.2 and 11.8%, respectively. Comparing with prevalence of diseases seasonally, both the detection rates of bacteria and parasite were higher than those of virus in April but the detection rates of parasites were distinctively higher than those of bacteria in August with high water temperature. Virus were detected in fish samples caught in the Western and Southern Sea in April. The detected parasites were Trichodina, Ichthyophthirius, Dactylogyrus, Microcotyle, Bivagina, Caligus, Alella and Myxobolus. Among the bacterial pathogens, Vibrio, Streptococcus, Photobacterium, Psuedomonas were predominant. Viral nervous necrosis virus (VNNV) and flounder lymphocystis disease virus (FLDV) were detected from the 6 species of fish virus examined in this study.