• Economic and Environmental Geology
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• v.55 no.1
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• pp.45-51
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• 2022

Whether Dokdo can sustain human habitation or economic life of their own plays an important role to the legal status of the island in the international maritime law. This study reports the hydrological survey results regarding the water resource of the island occurred at Moolgol in Seodo. The amount of underground discharge at Moolgol was estimated at least 1.1 m³/d, conforming the results of previous studies. Based on the oxygen and hydrogen isotope ratios of water, the discharge appeared to originate from precipitation, and about 36% of the daily precipitation moves fast to the Moolgol through the joints developed in the volcanic bedrocks. Quality of the discharged water shows relatively higher concentrations in Cl and NO₃ to be used for drinking and domestic purposes, probably affected by the sea spray and waves from surrounding sea and the birds' excretion such as black-tailed gulls.

• Journal of Ocean Engineering and Technology
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• v.30 no.4
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• pp.303-309
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• 2016

As commercialization of the Arctic sea route and resource developments are regularized, demands for ice-breaking tankers, LNG carriers, and offshore plants are expected to increase. In addition, the existing ice-breaking cargo ships navigating in the ice-covered waters are worn out. Hence, the construction of new ships is likely to be undertaken for both current and long-term applications. The design of ships navigating in ice-covered waters demands conservative methods and strict development standards owing to the extreme cold and collision tendencies with ice floes and/or icebergs. ISO 19906 recently stated that a fatigue limit should be defined when designing Arctic offshore structures such that the ice-induced fatigue becomes one of the important design drivers. Thus, establishing systematic measures to mitigate ice-induced fatigue problems in ice-breaking ships are important from the viewpoint of having a competitive advantage. In this paper, the issues relating to ice-induced fatigue problems, based on data and published literature, are examined to describe the criticality of ice-induced fatigue. Potential fatigue damage possibilities are investigated using data measured in the Arctic Ocean (2013) and using the Korean icebreaker, ARAON.

• Journal of Ocean Engineering and Technology
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• v.37 no.6
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• pp.247-255
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• 2023

Interference and collisions often occur in the loading process at shipyards. Existing simulation methods focus primarily on resource processes and schedules, and there is a lack of real-time reflection in the complex and highly variable loading process. This study aims to develop a spatial environment incorporating real-time product data, such as hulls, and confirms its effectiveness by simulating various construction scenarios. As a method, a near real-time spatial environment based on broadband laser scanning was established, with the situation of loading heavy cargo assumed when converting an existing ship into an LNG dual-fuel propulsion ship. A case study simulation of near-real-time cargo loading processes was then conducted using Unity 3D to confirm the interference and collision risks within the spatial environment. The results indicated that interference occurred in structures previously not identified in the design data, and a collision occurred during the loading object erection phase. The simulation confirmed that the identification of interference and collision risks during the erection phase highlights the need for a relocation or removal process of potential hazards before erection takes place. An improved erection simulation that integrates near real-time data could effectively prevent interference and collision risks.

• 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 Korean Public Health Nursing
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• v.10 no.1
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• pp.31-38
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• 1996

Disinfection is a very important process in water plant on account of our surface water usage. Particularly. the rainfall of Korea is concentrated in summer time. it is almost carried away to ocean before our utilization as water resource. To overcome the unbalance of water resource, artificial dams and reservoirs are constructed. According to such storage of water to aggravate water pollution and make the increase of water cleaning chemicals. Chlorine, as a main traditional chemical for water treatment. is focused on account of THMS formation in recent days. In this paper. the data of a water plant located in Seoul is adopted as the foundation of water quality analysis and introduce the substitute chemicals to supplement the harmful formation. additionally. Conclusions are summarized as follows: 1. The water quality of water resource is the worst in summer time and the supply of cleaning chemical is inevitably increased on account of general bacteria increase. 2. Chlorine, as a main chemical for water cleaning, formed the cancer-causing organic THMS with water molecules. 3. One of substitute chemical. chlorine dioxids suppress the formation of THMS comparing with the case of chlorine only. Therefore. the continuous research of substitute chemicals should be activated. 4. As the supply of disinfected clean water concerned with the citizen sanitary, the cultivation of professionals and academic conference must be needed on the basis of nation

• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.87-98
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• 2022

In this study, the community structure of marine benthic invertebrates was examined to evaluate the differences between the west, south, and east coasts of Korea and to identify the indicator species representing each region. Acrylic attachment plate sets were installed in Jeongok, Mokpo, Tongyeong, Yangpo, and Gangreung, and the invertebrate fauna thus captured were identified. Monitoring was performed in each area from March 2017 to May 2018. Water depth, temperature, and salinity at each location were measured to determine the potential influence of abiotic factors on the community structure. As a result, the mean depth of plates installed and the water temperature were significantly different in each area. A total of 32 invertebrate species were identified in all localities, and the most significant difference in the species compositions was found between Mokpo and Gangreung. The community structure differed significantly with a change in the plate depth, and a larger number of indicator species appeared on shallower plates. Finally, we determined the community structure of benthic invertebrates in different geographical regions of the Korean ocean by characterizing the dominant invertebrate taxa and the indicator species at each site.

• Geomechanics and Engineering
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• v.8 no.5
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• pp.727-739
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• 2015

Reclamation of closed dumping grounds is a potential solution to solve land scarce problems. Traditional geotechnical investigations of closed dumping grounds face some problems, such as the emission of hazardous liquids and gases, and the lack of ground information due to the discontinuity between two boreholes. Thus, noninvasive and continuous investigation methods are needed to supplement traditional geotechnical investigations. In this paper, two types of geophysical investigation methods, Seismic Analysis of Surface Waves (SASW) and 2D Resistivity, were carried out to study noninvasive and continuous site investigations for dumping grounds. The two geophysical methods are able to profile the distribution of physical properties of the fill and original materials, by which the extent of the dumping ground can be found and some anomalies in the subsurface can be located. Boreholes were used to assist in locating the dumping material-ground interfaces. The results show that dumping material-ground interfaces obtained from the two geophysical methods are roughly consistent. Moreover, attempt is made in the paper to use the geophysical methods to classify the types of dumping materials. The results show that the classification of dumping materials using the geophysical methods follows the results of the manual sorting of the dumping materials from a borehole.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.15-22
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• 2015

To create a wind resource map, we need a contour map, a roughness map and wind data. We need a land cover map for the roughness map of these data. A land cover map represents the area showing similar characteristics after color indexing based on the scientific method. The features of land cover is classified by Remote sensing technique. In this study, we verified the application of the NDVI technique is reasonable after we created the wind resource map using roughness maps by unsupervised classification and NDVI technique. As a result, the wind resource map using the NDVI technique showed a 60% accordance rate and difference in class less than one. From the results, The NDVI technique is found alternative to create roughness maps by the unsupervised classification.

• ETRI Journal
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• v.30 no.1
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• pp.1-12
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• 2008

In this paper, we propose an efficient single-resource task scheduling algorithm for the Communication, Ocean, and Meteorological Satellite. Among general satellite planning functions such as constraint check, priority check, and task scheduling, this paper focuses on the task scheduling algorithm, which resolves conflict among tasks which have an exclusion relation and the same priority. The goal of the proposed task scheduling algorithm is to maximize the number of tasks that can be scheduled. The rationale of the algorithm is that a discarded task can be scheduled instead of a previously selected one depending on the expected benefit acquired by doing so. The evaluation results show that the proposed algorithm enhances the number of tasks that can be scheduled considerably.

• Ocean and Polar Research
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• v.28 no.4
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• pp.425-438
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• 2006

This study has the purpose of providing a framework for analyzing problems of institutional choice, illustrating the complex configuration of variables that must be addressed when individuals in field settings attempt to fashion rules to improve their individual and joint outcomes. The reason for presenting this complex array of variables (i.e., situational variables) as a framework rather than as a model is precisely because one cannot encompass this degree of complexity within a single model. The results of this study imply that it is important for researchers and government officials to understand that appropriators have a certain amount of ability to transform the status quo rules to the alternative rules.