• Ocean and Polar Research
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• 제36권4호
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• pp.367-371
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• 2014

In early 1990s, the Korean government has launched a deep-sea research program to secure the stable long-term supply of strategic metallic minerals including Cr, Cu and Ni. Through the pioneering surveys, Korea registered $150,000km^2$ of Mn-nodule field in the Clarion-Clipperton area, the NE equatorial Pacific to the international sea-bed authority (ISA) in 1994. Following the ISA exploration code, the final exclusive exploration area of $75,000km^2$ was assigned in 2002, based on results of eight-year researches of chemico-physical properties of nodules, bottom profiles and sediment properties. Since that time, environmental studies, mining technical developments including robot miner and lifting system and establishment of smelting systems were accompanied with the detailed geophysical studies to decipher the priori mining area until 2009. Major points of the recent Korea Mn-nodule program are deployed on a commercial scale until 2015. In order to meet the goals, we developed a 1/5 scaled robot miner compared to commercial one in 2012 and performed a mining test at the water depth of 1,370 m in 2013. In addition, detailed 25,000 scaled mining maps in the priori area, which can provide operation roots of the miner, will be prepared and an environmental-friendly mining strategy will be pursued based on the environmental impact test and environmental monitoring.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.235-241
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• 2017

Purpose: It is to develop an agricultural three-directional dumping vehicle that can help farmers reduce intensive labor when carrying heavy loads and for easy dumping. In addition, a novel mechanism was applied for controlling the direction of the tilting cargo box by using a single hydraulic cylinder and simple apparatus. The overturning safety was analyzed to provide safe-use ground slope region of the vehicle to be used at upland fields and orchards. Methods: The developed three-directional dumping vehicle was constructed using a cargo box, vehicle frame, driving components, lifting components, and controller. The novel mechanism of controlling the dumping direction involves the operation of two latching bars, which selectively release or collapse the connecting edge between the vehicle frame and cargo box. A multibody dynamics analysis software (RecurDynV8R5) was used to determine the safe-use ground slope area when tilting the cargo box at slopes. A computer analysis was conducted by increasing the ground slope while rotating the vehicle when the cargo box comprised loads of 300 and 500 kg and stacking heights of 40 and 80 cm, respectively. Results: The three-directional dumping vehicle was successfully manufactured, and the cargo box was tilted at $37^{\circ}$ and $35^{\circ}$ for dumping forward and sideways. The latching bars were manually and selectively collapsed with the vehicle frame to control the dumping direction. When forward dumping, the safe-use ground slope was over $20^{\circ}$ in all vehicle directions and loaded conditions. Conclusions: A three-directional dumping vehicle was developed to reduce labor-intensive work in the farming environment. The user can easily control the dumping direction by using the control panel. The vehicle was safe to be used in most of the Korean upland fields and orchards (area over 96%) for the forward dumping.

• 한국환경복원기술학회지
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• 제23권6호
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• pp.1-14
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• 2020

Under the 「National Land Planning and Utilization Act」, Development Restriction Zones(DRZ) is one of the designated use district where the Minister of Land, Infrastructure and Transport deems it necessary to control urban development in order to prevent urban sprawl and conurbation and ensure a healthy living environment for citizens by conserving the natural environment surrounding metropolitan cities. DRZ was first designated around the Seoul Metropolitan city in 1971, and had been expanded to the 14 metropolitan areas across the country since 1977. The designated areas were accounted for about 5.4% of the total national land and its importance was demonstrated by contributing to control urban sprawl, curbing real estate speculation, and providing green space to citizens. However, DRZ has been repeatedly relaxed its regulations and allowed development under government. As a result, much of the green areas was damaged and several cities were merged and extended(conurbation). In particular, deregulation implemented for the purpose of securing land as part of national projects and local outstanding business(i.g. constructions of national rental housing, industrial complex, and international stadium) have caused continuous environmental damage around the metropolitan cities. In addition, the habitat fragmentation is in serious situation. Thus, the systematic plans for managing DRZ are necessary, since it is concerned that urban environment become deteriorate in the mid- to long-term. This study aims to continuously protect the urban environment from lifting DRZ. Therefore, firstly, we examined the environmental status through analyzing DRZ Management Plan which shall be drawn up by the Special Metropolitan City Mayor, the Metropolitan City Mayor or the Mayer/Do governor having jurisdiction, every five years to collectively manage DRZ. Secondly, we investigated the actual condition in DRZ based on the case study of Management Plan in Metropolitan areas(i.e. Seoul Metropolis, Gyeonggi-do, and Incheon Metropolis). Finally, we suggested the seven feasible improved political plan for managing DRZ.

• Ocean and Polar Research
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• 제36권4호
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• pp.383-394
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• 2014

The surface sediments from the manganese nodule exploration area of Korea in the Clarion-Clipperton fracture zone were investigated to understand the resource potential of and emplacement mechanism for rare earth elements (REEs). The sediments are categorized into three lithological units (Unit I, II and III from top to bottom), but into two groups (Unit I/II and Unit III) based on the distribution pattern of REEs. The distribution pattern of REEs in Unit I/II is similar to that of Post-Archean Australian Shale (PAAS), but shows a negative Ce anomaly and enrichment in heavy REEs (HREEs). In Unit III, the HREE enrichment and Ce anomaly is much more remarkable than Unit I/II when normalized to PAAS, which are interpreted as resulting from the absorption of REEs from seawater by Fe oxyhydroxides that were transported along the buoyant plume from remotely-located hydrothermal vents. It is supported by the PAAS-normalized REE pattern of Unit III which is similar to those of seawater and East Pacific Rise sediments. Meanwhile, the PAAS-normalized REE pattern of Unit I/II is explained by the 4:1 mixing of terrestrial eolian sediment and Unit III from each, indicating the much smaller contribution of hydrothermal origin material to Unit I/II. The studied sediments have the potentiality of a low-grade and large tonnage REE resource. However, the mining of REE-bearing sediment needs a large size extra collecting, lifting and treatment system to dress and refine low-grade sediments if the sediment is exploited with manganese nodules. It is economically infeasible to develop low-grade REE sediments at this moment in time because the exploitation of REE-bearing sediments with manganese nodules increase the mining cost.