• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.79-87
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• 2020

In the field of logistics, the maritime shipping industry plays a critical role as the backbone of global trade activities. Nevertheless, previous studies on the commercialization and benefits of blockchain technology are limited in the field of marine logistics. Thus, the purpose of this study was to predict the benefit for each group involved in marine logistics when blockchain technology is applied. As such, 21 factors of benefits were selected for seven major logistics groups (financial institutions, freight forwarders, inland transportation, ocean carriers, port operators, port-related government authorities, and shippers) to study the benefit expected for each through the commercialization of blockchain technology. Based on the results, a different benefit level is expected for each group when blockchain technology is used. In order, ocean carriers (0.155), inland transportation (0.150), financial institutions (0.153), port operators (0.145), freight forwarders (0.142), port-related government authorities (0.129), and shippers (0.126) were found to benefit most from the use of blockchain technology. This study has industrial implications in that it presents the benefits expected when blockchain technology is realized and used in marine logistics by groups involved in logistics transactions.

• Journal of Internet of Things and Convergence
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• v.2 no.4
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• pp.9-14
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• 2016

The range of use of drones is gradually expanding from military to commercial applications. In the field of agriculture, there have been many studies to utilize drones, but there have been relatively few efforts to utilize drones in the marine and fisheries sectors. In this paper, we propose drones and system requirements for marine and fisheries applications. Marine and fisheries monitoring using drones is expected to be more effective and cost effective than existing methods.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.69-73
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• 2002

There have been few reports on the survey of pathological findings of cetaceans stranded on the coast of Japan. This is partly because of lack of the procedures and/or network of systemic sampling of fresh tissues for the pathological study of stranded marine mammals. In contrast, there are a numbers of reports on the cause of illness and death in wild, free-living cetaceans examined in other countries; the commonest cause of death was parasitic and bacterial pneumonia except for entanglement in fishing gear. Anthracosis, lung and hilar lymph nodes polluted by suspended particulate matter in the air, has been recently found in some cetaceans stranded on the coast of Japan. In addition to the data from the chemical analysis of tissues, scientific data obtained from pathological study of stranded marine mammals would be also one of the useful base for the assessment of global environment. Usefulness of metallothionein in the hepatopancreas of crabs as a biomarker of marine pollution monitoring was also discussed in this study.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.894-901
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• 2012

For more efficient use of the high pressure water-jet in rehabilitation of the water pipes, we have studied the water-jet cleaning motion of the in-pipe robot with screw drive. The mathematical models of the water-jet in the straight and the curved pipe (90 degrees elbow), representative features of the water mains, were designed to understand the water-jet motion and simulations have been performed. Furthermore the experiments has been conducted to validate the simulations by using the prototype in-pipe robot in the 3-D pipeline. The simulation results show that the water-jet motion in the straight pipe has a constant water-jet interval, whereas the motion in the curved pipe is changed by its position. By the comparison of the simulation and the experimental results, we have demonstrated that the simulations successfully estimate the water-jet motion inside the water pipes. Therefore in-pipe robot operators can predict a water-jet motion for a target water pipe through the simulation and flexibly make a proper water-jet motion by changing the robot configurations before a cleaning work.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.513-519
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• 2013

The fishing industry in Europe has faced environmental, economic, and social challenges. Since the early 2000s, a key tool in addressing these challenges has been information and communication technology (ICT), which has helped to modernize fishery systems in European Union (EU) countries. The ICT used in EU fisheries can be categorized broadly as 1) macro-technologies such as satellite and other remote sensing technologies in combination with geographical information systems, 2) micro-technologies adapted for fishing vessels such as echo sounders, ship navigation devices, and mobile communication devices to connect fishermen and consumers, and 3) onshore micro-technologies related to internet technology and mobile devices. The European Monitoring Center on Change has used ICT to effectively manage fisheries bio-resources. This use of ICT has contributed to the development of sustainable and competent fisheries in the 2000s, even though the knowledge-sharing practices involved are contrary to the long tradition of autonomy within the fishery industry.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.267-268
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• 2006

The cylinder cover stud of low-speed marine diesel engine is more than just a stud. It is a large structural element occasionally weighing over 200 kg used for assembling the combustion chamber components. Therefore, to understand the structural behavior of the stud and design it safely is quite important considering a catastrophic failure which can be arisen from an inadequate use of it. In this paper, the analysis results of the structural behavior of the stud is introduced. Strain measurement results compared with FE analysis results are summarized. The results showed that 1) the stud stress increased with engine operating load, 2) the maximum stress amplitude was about 10 MPa which is far smaller than the stud's fatigue strength of 61 MPa, 3) the stress ratio is higher than 0.9 and the stud's load factor is about 20 %, and 4) about 7 % of initial pressure tightening load was reduced while changing to a nut tightened condition.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.291-300
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• 2013

The main purpose of this study is to analyse economic feasibility of low-carbon-oriented gear for anchovy boat seine. The results of benefit/cost analysis showed that use of the low-carbon fishing gear is economically feasible. Considering the fuel saving and relatively low $CO_2$ emission by reducing the resistance of gear, net present value by such type 1 gear improvement was estimated about -2,490 ~ -1,580 million won with the benefit-cost ratio 0.81~ 0.88. And net present value by such type 2 gear improvement was estimated about 6,540 ~ 7,780 million won with the benefit-cost ratio 1.79 ~ 1.94. Development of lowcarbon trawl gear would render significant contributions to reducing $CO_2$ emission in fishing operations and lead to reduce fishing costs due to fuel savings.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.389-397
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• 2010

The in vitro toxicities of three crude oils of the Hebei Spirit were examined on laboratory grown plankton, with a focus on the effects of a dispersant. The specific growth rate of phytoplankton and the mortalities of two zooplankton were measured in response to exposure to various concentrations of water accommodated oil, dispersant or both. The effects of the oils varied among the plankton, but were generally low within the range of the oil concentrations used, with little difference in toxicity among the three oils. Such low toxicity appeared to be associated with weathering of the crude oils. Exposure to the dispersant, however, dramatically increased the mortality of zooplankton, with complete inhibition of phytoplankton growth. No synergistic toxic effect was observed with the crude oil and dispersant combination. A better decision making process could be crafted for future application of dispersant in the event of an oil spill in Korean waters to better protect the marine plankton community from the excessive use of dispersant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.543-549
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• 2011

An underwater speaker was developed for use as an acoustic deterrent device that transmits acoustic energy through the water omnidirectionally over a broadband frequency range to eliminate marine mammal attacks and to prevent physical damage to the inshore and coastal fishing grounds of Korea. The underwater speaker was constructed of two vibration caps machined from 6061-T6 aluminum alloy and a stack of PZ 26 piezoelectric ceramic rings (Ferroperm Piezoceramics A/S) connected mechanically in series and electrically in parallel. The performance characteristics of the underwater speaker were measured and analyzed in an experimental water tank of $5\;m{\times}5\;m{\times}6\;m$. The peak transmitting voltage response (TVR) was measured at 11.16 kHz with 163.45 dB re $1\;{\mu}Pa$/V at 1m. The underwater speaker showed a near omnidirectional beam pattern at the peak TVR resonance frequency. The usable frequency range was 4-25 kHz with a lower TVR limit of approximately 140 dB. We conclude that this underwater speaker could be satisfactorily used as an acoustic deterrent device against marine mammals, particularly the bottlenose dolphin, to protect catches and fishing grounds as well as the mammals themselves, for example, by keeping them away from fishing gear and/or vessels.

• Ocean and Polar Research
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• v.34 no.1
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• pp.85-91
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• 2012

Physical properties such as sound speed contrast (h) and density contrast (g) of the interested target are key parameters to understand acoustic characteristics by using theoretical scattering models. The density and sound speed of moon jellyfish (common jellyfish, Aurelia aurita s.l.) were measured. Sound speed contrast (h) was measured from travel time difference (time-of-flight method) of an acoustic signal in a water tank for APOP studies (Acoustic Properties Of zooplankton). Density contrast (g) was measured by the displacement volume and wet weight (dual-density method). The sound speed remained almost constant as the moon jellyfish increased in bell length. The mean values${\pm}$standard deviation of h and g were $1.0005{\pm}0.0012$ and $0.9808{\pm}0.0195$), respectively. These results will provide important input for use in theoretical scattering models for estimating the acoustic target strength of jellyfish.