• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.157-165
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• 2000

A small hydraulic winch system with an automatic tension control unit was designed to improve the work efficiency of coastal small vessels and the dynamic response characteristics of the winch system operated in the open loop condition was investigated. The inlet and the outlet pressures in hydraulic motor, the torque and the rotating speed of winch drum were measured as a function of time, and the behaviour in autotension mode for stepped load changes was analyzed. The results obtained are summarized as follows : 1. The developed winch system for coastal small vessels will result in better fishing with improved efficiency and lower manpower consumption by remote control of winch system. 2. The rotating delay times of winch drum for on/off operations of solenoid valve were 0.09 see at CW mode and 0.04 sec at CCW mode, respectively. After the solenoid valve was controlled, response characteristics were unstable slightly but showed good tracking behaviour over short time. 3. The driving torque of winch system in autotension mode was kept almost constant of 55.9 kgf·m, and 11.1 then the rotating speed of winch drum was kept almost constant of 5.1 rpm in the larger torque than 55.9 kgf·m and 11.1 rpm in the lower torque than that. 4. The 5% settling times in the transient response characteristics of autotension mode under rapid increasing and decreasing conditions of load were 0.12 sec and 0.2 sec, respectively, and then the rotating speeds were 11 rpm and 5.3 rpm, respectively. 5. The tracking behaviour of torque and rotating speed by remote control operation were stable within 0.23 sec at CW mode and 0.37 sec at CCW mode, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.450-457
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• 2019

Sedimentation is a common problem for river ports. But its intensity depends on the rate of sedimentation, channel shape and size, hydrodynamic behavior of the river and the importance of the port. High sedimentation rate in Yangon River has become one major issue for Myanmar as her largest port is located on the Yangon riverbank. As a result of the high sedimentation rate, shallow water area near the confluence of Yangon River, Pazundaung Creek, and Bago River keeps blocking the navigation channel to the Yangon Port, which also limits the size of vessel calling to Yangon Port. Therefore, studies to understand sediment transport process in Yangon River are required because the economic development of Myanmar highly relies on the Yangon Port. This paper aims to calculate the sediment transport and to predict the riverbed elevation changes in Yangon River by using Bagnold (1966) theory. Calculation result shows that huge difference can be found in the bed load transport between the rainy season and dry season in Yangon River, and thus the sedimentation problem would become more severe in the dry season when the transported sediments are reduced. The estimated sedimentation rate in dry season indicates that the rate of riverbed level rise near the Yangon Port area is about 0.063 m per year, which would lead to approximately 3.15 m rise in the riverbed level in next 50 yrs, considering the same workload of dredging to maintain the navigation channel.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.351-375
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• 2018

This paper aims to i) introduce the characteristics of HF ocean radar and the major results and information produced by the radar networks in the Korean coasts to the readers, ii) make an up-to-date inventory of the existing radar systems, and iii) share the information related to the radar operating skill and the ocean current data application. The number of ocean radars has been showing a significant growth over the past 20 years, currently deploying more than 44 radars in the Korean coasts. Most of radars are in operation at the present time for the purposes related to the marine safety, tidal current forecast and understanding of ocean current dynamics, mainly depending on the mission of each organization operating radar network. We hope this overview paper may help expand the applicability of the ocean radar to fisheries, leisure activity on the sea, ocean resource management, oil spill response, coastal environment restoration, search and rescue, and vessel detection etc., beyond the level of understanding of tidal and ocean current dynamics. Additionally we hope this paper contributes further to the surveillance activity on our ocean territory by founding a national ocean radar network frame and to the domestic development of ocean radar system including signal processing technology.

• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.86-93
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• 2024

This study evaluates the stability of a 4.99-ton small coastal fishing boat using data interpreted according to the second-generation intact stability criteria of the International Maritime Organization (IMO). The focus is on the ship's behavior under surfriding/broaching conditions during sea navigation, ensuring compliance with international standards. The data processing procedures presented apply stricter criteria than the first-generation intact stability standards to assess the ship's intact stability in waves. However, if the vessel deviates from its standard condition, a separate intact stability assessment based on actual loading conditions is necessary. The surfriding/broaching data processing procedures utilized a program developed by the Shipbuilding and Ocean Equipment Research Center at Kunsan National University. The results were analyzed and compared in detail according to the conditions, parameters, and criteria used for the calculations. Additionally, the study presents the results of Level 1 and Level 2 assessments according to IMO regulations, providing a parametric analysis of the small coastal fishing boat's stability. This allows for the evaluation of intact stability in hydrodynamic motion scenarios.tract.

• Journal of Fisheries and Marine Sciences Education
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• v.14 no.2
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• pp.149-160
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• 2002

I have been analyzed the marine accidents during 10years(1992~2001) based on the maritime inquire court decision, the results were as follows: 1. The rate of accident occuring were showed fishing boat(69.9%), freighter(12.3%), tanker(4.3%), tug boat(3.8%), passenger boat(2.1%) by the usage. 2. The marine accident had been showed operational fault(67.3%), mishandling of engine equipment(21.7%), meteorological condition, etc(11%) by the reason, most accidents had been occured by the operator fault and rack of experience. 3. The marine accidents had been showed damage of hull and engine(27.5%), collision(24%), foundering(11.3%), fire(3.9%), agrounding(10%), by the kind of accidents. 4. The accidents had been occured (74.6%) at the coastal sea, harbour and (25.4%) at the open sea by the sectors. The accidents of the vessel less than 500ton were much increased (54.3%) also, The accidents were much occured at the time between 0400~0800 hours by the time.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.29-39
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• 2012

Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen's logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.1
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• pp.40-47
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• 2006

Large scale marine biodiversity studies in China have been carried out for more than half a century since the founding of the Institute of Oceanology, CAS, in 1950. Through a series of coastal and multi-disciplinary oceanographic investigations in the shelf seas and biodiversity studies since the late fifties, a total of 20,278 species of marine biota have been recorded upto 1994. Recent intensive studies have further revealed the richness of marine biota of the China seas,a great number of marine species have been found and many new taxa established. The total species number of main biotic groups increased about 50 % of that estimated in 1994. The results have promoted the fast development of China's marine fisheries, medicine (drug) and biodiversity research, and attracted many scientists, particularly bio-technologists, to join their studies. Environmental deterioration and human activity strongly stressed the sustainable development and conservation of marine bio-diversity, and resulted in the increase of end angered species as record ed in the new published ${\ll}$China Species Red List${\gg}$ with the threatened category of species assessed by adopting the new IUCN criteria. To further reveal the high diversity and their history, present status and future of marine organisms existed in the world ocean, an international Project ${\ll}$Census of Marine Life (CoML)${\gg}$ was established in 2000 in the USA. Scientists predicted that 2 to 3 times of numbers of the known species will possibly be found in various marine habitats, particularly the abyssal ocean. The Research Plan and the Projects were briefly introduced, and the relationship between marine biodiversity and biotechnology was discussed. The Project planned to apply new and high techniques and new equipments on board research vessel and in laboratory. Brief review of recent advances of Chinas' marine biodiversity and biotechnology studies indicated that fascinate results have been achcieved; but further effort should be made to promote the continuous advance of our basic researches and their application in related production and maintain sustainable development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10b
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• pp.11-25
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• 1998

Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.2
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• pp.77-84
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• 2009

This paper is to investigate the effect of the immersion time in the traditional hairtail hand line for developing the fishing methods and the fishing gear in the coast of jeju. The operating of 32 times was made with each different immersion time of hairtail hand line, and the relations between the catch and the immersion time were examined. As the result, targeted species rate was over 98% of total catch. From about 800 seconds after casting, the hooking rate was decreased and the bite loss rate was increased, it seems to be made by the decreasing factors of predators including the cutting of branch lines etc. In addition, it was supposed that the hooking rate and the bait loss rate had a deep connection with feeding time zone. The level of the correlation coefficient of the bait loss rate according to the immersion time was 0.54 at $p{\leq}0.01$, in the case of the hooking rate, 0.59 was chosen after about 800 seconds. The hooking rate and the bait loss rate according to the hook number were not irrelevant to the fish school layer. Additionally, it was assumed that the bait loss rate was related to the depth of water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.78-82
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• 2010

Vessel numbers and fuel consumption by South Korea's offshore and coastal fisheries have continuously declined since 2000. Using the 2006 Intergovernmental Panel on Climate Change Guidelines, $CO_2$ emissions by South Korea's fishery industry (fishing and aquaculture, excluding deep-sea fishing) were calculated by the default $ CO_2$ emission factor and fuel consumption by fuel type, Emission of $CO_2$ was estimated to be 3.22 million $tCO_2$/year in 2007 for fisheries (excluding deep-sea fishing); when including deep-sea fishing, the estimated value increased to 4.11 million $tCO_2$/year. Fuel consumption per tonne of fishery production was 498 L, and the amount of $CO_2$ emission per tonne of production was 1.62 $tCO_2$. To calculate $CO_2$ emission more exactly, we must develop a system to compile energy balance statistics and introduce life-cycle assessment for the fishery industry.