• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1083-1095
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• 2023

Recently, the demand for low-voltage, high-capacity ESS is rapidly increasing due to the revitalization of the e-mobility industry, which is mainly powered by electricity. In addition, the demand for portable power banks is rapidly increasing due to the revitalization of leisure industries such as camping and fishing. The ESS with this structure consists of a small number of series cells and many parallel cells, resulting in a system with a large rated current. Therefore, the number of power devices for cell balancing configured in series is small, but a balancing device with a large current capacity is required. Construction of a constant temperature device in such a low-voltage, high-current ESS is difficult due to economic issues. The demand for an active balancing system that can solve the passive balancing heating problem is rapidly increasing. In this paper, propose a power feedback fly-back topology that can solve the balancing heating problem. The characteristic of the proposed topology is that a series-connected voltage sharing voltage is used as the input of the flyback converter, and the converter output is connected to one transformer. In this structure, the converter output for cell voltage balancing shares magnetic flux through one high-frequency transformer, so the cell voltage connected to the converter automatically converges to the same voltage.

• Journal of Embryo Transfer
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• v.19 no.1
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• pp.27-34
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• 2004

This study evaluated the efficiency and compared with different materials of loading vessels for vitrification-plastic/glass, copper grid and nylon. The loading method, vitrification, cryop-reservation and warming method of the oocytes were examined. The loading samples prepared in manual or company-made and sterilized, loaded the COCs selected on each samples and cultured for maturation during 40 hours, and then exposed sequentially to ethylene glycol solution. Thawing method was reversely treated and exposed for warmed oocytes. After oocytes were thawed, fertilized and cultured in vitro for 3-4 hours, rates of development and morphological appearance were examined. The results were as summarized: ㆍOPS from company-made or hand-made of the hematocrit micropipettes, NLS from fishing line and EMG from company-made for EM were used for loading oocytes, respectively. ㆍThe efficiency of freezing method and loading convenience were orderly higher in OPS, NLS and EMG. The optimal capacity per vessel was orderly lowered in NLS, EMG and OPS, respectively. ㆍAfter oocytes were warmed, the recovery rate, morphology and rate of development were orderly higher in OPS, NLS and EMG, respectively. ㆍIn conclusion, OPS has the advantages of achieving a little more survival and preserving results than other two loading methods.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.3
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• pp.442-451
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• 2008

The purpose of this study is to analyze the impacts of the rapid rise in oil prices on fisheries economy. Even though fishery oils are tax exemption items, such increase in oil prices put a great amount of pressure on Korean fishing operations. Because basically the recent oil shock is externally given, Korean fisheries themselves have little capacity to cope with the disruption of economic environments. The research results turned out that Korean fisheries are extremely vulnerable(or fragile) to external shocks. In this regard, government support issues of oil costs are in the center of debate. It is widely recognized that direct/indirect government financial supports or subsidies would result in economic inefficiency in expense of equity. However, there are second best theories which may justify government intervention into the markets. This second best theory is translated into the constitutional law that instructs the government to protect and promote the primary industries including fisheries, agriculture, and midium/small-scale enterprises. It is apparent that the constitutional law would provide the government with a variety of policy instruments such as more active buy-back programs, tax exemptions and technological development to deal with fisheries economic hardship due to the external pressure such as high oil prices and international fishery orders.

• New & Renewable Energy
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• v.17 no.3
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• pp.24-31
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• 2021

Through 'The Renewable Energy 3020 Implementation Plan' for carbon neutrality, the government promised to raise the proportion of renewable energy generation to 20% and renewable energy installation capacity to 63.8% by 2030. Therefore, we plan to test a 5.5 MW offshore wind turbine near Maldo, Gunsan. In this project, we measure the level of public acceptance and perform ordinary least squares (OLS) regression analysis to show the determinants of public acceptance. The regression results are as followed. First, it is judged that the closer the distance to the offshore wind turbine, the more the economic effects considered by residents. Second, especially in Maldo, the experience of being discriminated from the Saemangeum project, is understood to have caused distrust in the surrounding fishing villages chief/Fisheries Cooperatives, converted into a local community effect. Finally, the policy implications are as follows. First, a bottom-up problem-solving method is required to improve public acceptance, based on the Living Lab. Second, the island community may be indifferent to the briefings or forums of outsiders. Therefore, a gradual approach is required through (in)formal channels based on reliability from a long-term perspective with nearby universities and research institutes using SamsØ Energy Academy.

• The Journal of Fisheries Business Administration
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• v.31 no.1
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• pp.115-133
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• 2000

The policy of suppling tax-exempt fishery oil in Korea has a history of almost 40 years, which was initiated by the National Federation of Fisheries Cooperatives in 1965. In 1999 the volume of fishery oil supplied to the earning fishermen and fishing entrepreneurs amounted to 8,390 thousand DM, 500 billion won in total. This paper analyzes the oil supplying system to fishermen in Korea and shows that the structural obstacles to the stable provision of fishery oil lies in the ineffective bargaining power (fixing price). Provided that the NFFC as a buyer, which is not equipped with the storage facilities for oil bids for a unit-price contract of fishery oil, there exists a possibility of collusion among 5 local oil refineries corporations to influence the oil price, making it difficult to reach a resonable price of oil. Though the international bids and direct imports following the liberalization of oil imports would help lower the unit price, purchasing and importing the oil out of season at a lower price would not be guaranteed without the oil storage facilities. Furthermore, the current supply system of oil is quite vulnerable to the extraneous factors and, say when the oil price soars unpredictably, it is almost impossible to supply low - priced fishery oil to fishermen. The National Federation of Fisheries Association of Japan(Zengyoren), for instance, possesses 10 oil storage facilities, which had been built across the country during the last 20 years (1964-1984). The storage capacity of these facilities reaches 0.6million DM(by kind, 0.56million DM for A heavy oil, 38thousand D/M kerosene, 5thousand D/M for diesel fuel oil). Allowing no intermediary of production associations(fisheries cooperatives) the NFFA's capacity for keeping oil in reserve rises much higher. As these storage facilities can keep the oil amounting to as much as of 70 days demand in reserve, a stable supply of fishery oil on favorable terms is secured. In contrast with Japan case, unequipped with the storage facilities for fishery oil, Korea does not have much bargaining power for bringing down the price of fishery oil. To make matters worse, the oil storing capacity of the member cooperatives is the volume of only 8 days demand. In case the oil price rises, it is almost impossible to supply the oil to the fishermen at a price lower than the price risen.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.321-337
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• 1997

Rapid change in the technological environment of marine transportation and the development of the ocean shipping industry have fostered a revolution in the port system. This in turn has caused major changes in the function and use of port in Korea. Aside from this. Mokpo Port, however continues to decline, because the existing port facilities and related subsystem are already obsolete with no chance of regaining operational effectiveness and treatment for proper implementation. Although a few studies have been done on the Mokpo Port, has not been found, any reseach for the analytical approach to the transportation system of it. This paper aims to make an extensive analysis of the physical distribution system in Mokpo Port focusing on the coordination of subsystems such as navigational aids system, quay handling and transfer system, storage system and inland transport system. The base of introduced simulation tool here is the queueing theory. The overall findings are as follows; 1. Among those vessels called at Mokpo Port in 1994, the average size of oceangoing vessels is 4,922.1 G/T, and the domestic is 317.8 G/T. The average arrival interval and service time of the domestic vessels are 6.0 hours and 24.1 hours respectively marking the berth occupation rate over 100%. Those for oceangoing vessels are 34.5 hours, 120.0 hours and 37.2%. In order to maintainin the berth occupation rate to 70% the capacity considering the 1994 of domestic piers must be extended to 145% and oceangoing vessels must be increased to 165% year called. 2. The capacity of approaching channel is enough to handle the total traffic volume. 3. Tugs are sufficiently being provided to handle all ships requiring their services 4. The capacity of storage and inland transportation systems are sufficient to handle the throughput and the yard stroage utilization rate of No.1 $\cdots$ No.5 is 4.5% and No.6 1S 30% of 1993's. 5. The utilization rate of LLc(Level Looping Crane) and PNT(PNeumaTic) are 2.7% and 18.8%, respectively. Practical solution and proposal for improvement of Transportation System in Mokpo Port are as follows; 1. To avoid the congestion in domestic pier introduction of a new port operation system is necessary allowing the domestic vessel to use the oceangoing pier. 2. To establish the port management information system to improve the efficiency of port operation. 3. To build a new storage system for high valued cargos including modernization of the present storage and handling system. 4. To insure the safety of navigation in approaching channel, The Vessel Traffic System including separation scheme is introduced. 5. To interest enormously on public relation to ship owner's association, shippers and consignees by showing that they can save cost and ship turnaround time in order to promote the call to Mokpo Port. At last, to be strategically change the function of Mokpo Port to the Leisure, Fishing & Ferry as well as Maritime port.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.453-465
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• 2017

UN adopted the 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs) in 2015, a set of 17 objectives with 169 targets expected to guide actions over the next 15 years (2016-2030). One goal expressly focuses on the oceans, that is, SDG 14 'Conserve and sustainably use the oceans, seas and marine resources for sustainable development'. More than 30% of fish stocks worldwide were classified by FAO(2016) as overfished. Globally, world capture fisheries are near the ocean's productive capacity with catches on the order of 80 million metric tons. Aquaculture production is increasing rapidly and is expected to continue to increase, but aquaculture encounters some environmental challenges, including potential pollution, competition with wild fishery resources, potential contamination of gene pools, disease problems, and loss of habitat. Accordingly, there have been a variety of world organization and conferences stressing the importance of the implementation of the ecosystem-based fisheries management(EBFM) to overcome these problems. Annual catch of Korean fisheries have shown continuously declining patterns since late 1990s. Most fish stocks are currently known to be over-exploited, and some stocks are depleted due to the increase in fishing intensity and over-capitalization of fishing fleets. Other reasons for the depletion are land reclamations and coastal pollution, which destroy spawning and nursery grounds along the coastal regions. Aquaculture production is also increasing rapidly in Korea. However, several important issues such as gene pool and interaction with capture fisheries should be considered. The EBFM approach should use the best available information coupled with a reasonable application of the precautionary approach. The EBFM has global relevance, and so the real challenge will be to develop and use reliable, robust and cost-effective means of assessing and monitoring the status of ecosystems and their resources, and rapid means of detecting any undesirable and excessive impacts that threaten sustainable use. Future fisheries education should take into account UN's SDGs, which were adopted to achieve the global 2030 agenda. However, there are some difficulties in the current fisheries education system in Korea. First, the current education organizations are limited within the old frame of traditional fisheries sciences. Second, the fisheries education is currently lack of the future-oriented education system and of customized schools or departments. Third, the on-going fisheries education has been based upon few educational policies which are sufficiently relevant to holistic SDGs of the global standard. Accordingly, directions to modern fisheries education for achieving SDGs would be, first, the transition of fisheries education structure into the future-oriented and customized education system. Second, fisheries education needs to shift to the new paradigm, which combines traditional fisheries science education with related fields such as oceanography and environmental sciences to adopt the concept of EBFM. Lastly, fisheries education should accompany relevant policies for effectively achieving SDGs.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.1
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• pp.1-7
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• 2008

Submarine cable is the most important IT infrastructure for international communication across oceans. However, a cable fault rarely happens by ship's anchor, fishing gears, submarine earthquake, and so on, and we need to improve on repair time for the reducing expenses of cable repair ship as well as the stability of high-capacity submarine optical network. There are several kinds of cable faults such as Shunt fault, Cable cut, Open fault and Fiber break. When a fault is occurred, cable landing stations(CLS) have to analysis failure quickly and accurately to find the type and the location of a cable fault. During the repair period, CLS should swiftly perform the tests requested by cable repair ship. In order to make rapid progress on cable repair, CLS test technique is very important. So, in order to reduce the repair time, this paper is studying the CLS test techniques of locating a submarine cable fault and of checking the splicing point performed by cable repair ship.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.38-53
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• 2018

The purpose of this study is to estimate potential yield (PY) for Korean west coast fisheries using the holistic production method (HPM). HPM involves the use of surplus production models to apply input data of catch and standardized fishing efforts. HPM compared the estimated parameters of the surplus production from four different models: the Fox model, CYP model, ASPIC model, and maximum entropy model. The PY estimates ranged from 174,232 metric tons (mt) using the CYP model to 238,088 mt using the maximum entropy model. The highest coefficient of determination ($R^2$), the lowest root mean square error (RMSE), and the lowest Theil's U statistic (U) for Korean west coast fisheries were obtained from the maximum entropy model. The maximum entropy model showed relatively better fits of data, indicating that the maximum entropy model is statistically more stable and accurate than other models. The estimate from the maximum entropy model is regarded as a more reasonable estimate of PY. The quality of input data should be improved for the future study of PY to obtain more reliable estimates.

• The Journal of Fisheries Business Administration
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• v.38 no.1 s.73
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• pp.71-96
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• 2007

This study is aimed to investigate how the structure of Korean and Chinese fisheries has been changed since the Fisheries Agreement between Korea and China came into effect. This investigation was accomplished from a comparative point of view by using statistic data in the literatures published by both Korea and China. Results of this study are summarized as follows; First, it was revealed that the decreasing rate of fish production of marine capture fisheries in Korea was lowered more by 5.1%, while it was decreased by only 0.1% in China. Second, comparative results on changes in production of offshore fisheries showed that the production of Korean offshore fisheries in 2003 was reduced by 26% compared to that in 1999, while the production of China offshore fisheries was decreased by 22%. In addition, although the production of marine capture fisheries in the East region of China was reduced by 10%, on the contrary, the production of marine capture fisheries in Liaoning, Hebei, Tianjin, Jiangsu, Zhejiang, and Fujian that have mostly impacted by the Korea-China Fisheries Agreement was increased by 7%. Third, results on fishing capacity of marine fisheries indicated that the number of vessels and total horse power in Korea were increased by 1.2% and 44.9%, respectively, while total tonnage was reduced by 23.9%, For China, the number of vessels and total horse power were increased by 0.5% and 12.6%, respectively. Total tonnage was also increased by 11.7%. Finally, the production per Korean vessel was decreased by 17.8% in 2003 compared to that in 1999. On the contrary, the production per Chinese vessel was increased by 8.1% in 2003. The production per tonnage was increased by 3.2% in Korea, while it was reduced by 2.7% in China. In conclusion, it could be said that the Korea-China Fisheries Agreement has had a positive impact on the fisheries production of China, while it has had a negative impacts on that of Korea, relatively.