• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.88-89
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• 2017

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.59.3-59.3
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• 2019

Very Long Baseline Interferometry (VLBI) is a special technique which can provide high angular resolutions of milliarcsecond and sub-milliarcsecond sales in radio astronomical observations. Recently, the mm/sub-mm VLBI observations becomes more widely available and related activities are increasing accordingly. In this talk, I'll introduce ongoing global mm-VLBI activities and EHT collaboration and our (Korean) contributions to them.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.489-500
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• 2014

In this study, remote handling strategies for a large-scale argon cell facility were considered. The suggested strategies were evaluated by several types of field test. The teleoperation tasks were performed using a developed remote handling system, which enabled traveling over entire cell area using a bridge transport system. Each arm of the system had six DOFs (degrees of freedom), and the bridge transport system had four DOFs. However, despite the dexterous manipulators and redundant monitoring system, many operators, including professionals, experienced difficulties in operating the remote handling system. This was because of the lack of a strategy for handling the installed camera system, and the difficulty in recognizing the gripper pose, which might fall outside the FOV (field of vision) of the system during teleoperation. Hence, in this paper, several considerations for the remote handling tasks performed in the target facility were discussed, and the tasks were analyzed based on ergonomic factors such as the workload. Toward the development of a successful operation strategy, several ergonomic issues, such as active/passive view of the remote handling system, eye/hand alignment, and FOV were considered. Furthermore, using the method for classifying remote handling tasks, several unit tasks were defined and evaluated.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.776-790
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• 2015

Background: The advanced spent fuel conditioning process facility (ACPF) of the irradiated materials examination facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI) has been renovated to implement a lab scale electrolytic reduction process for pyroprocessing. The interior and exterior structures of the ACPF hot cell have been modified under the current renovation project for the experimentation of the electrolytic reduction process using spent nuclear fuel. The most important aspect of this renovation was the installation of the argon compartment within the hot cell. Method: For the design and system implementation of the argon compartment system, a full-scale mock-up test and a three-dimensional (3D) simulation test were conducted in advance. The remodeling and repairing of the process cell (M8a), the maintenance cell (M8b), the isolation room, and their utilities were also planned through this simulation to accommodate the designed argon compartment system. Results and conclusion: Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.32.3-32.3
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• 2016

Available VLBI sources at high frequencies (e.g. >22GHz) are very limited - mainly due to atmospheric fluctuations that degrade coherence time and a power-law energy distribution of particles in case of AGNs. However, simultaneous multi-frequency VLBI receiving system of the Korean VLBI Network (KVN) and its powerful VLBI phase calibration technique offer benefits in finding more weak sources at millimeter wavelengths. Based on this aspect, multi-frequency AGN survey with the KVN (MASK) project, which aims to densify an existing a VLBI catalog of extragalactic radio sources at 22/43/86/129GHz is proposed as a KVN legacy program. We selected 1220 sources of AGNs that include known VLBI sources and new fringe-detected sources using the KVN at K-band (22GHz). Among them, 138 sources were observed as pilot experiments at 22/43/86/129GHz simultaneously and excellent VLBI detection results are achieved. Therefore, we expect that MASK will open a new era in VLBI science at millimeter wavelengths by providing unprecedented number of available sources in the Universe.

• Journal of Korean Historical Folklife
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• no.44
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• pp.7-37
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• 2014

The people of Silla was described as the descendants of Hwagwan(official of fire) on the tombstone of King Munmu(文武王), and Gim Yusin(金庾信) was described as the descendants of Shaohao Jintian(少昊 金天) and Huangdi Xuanyuan(黃帝 軒轅) on his tombstone. It says that the royal households of Silla and Gaya had common ancestor. Hwagwan was the official who took charge of fire management and the ritual for Antares(${\alpha}$ Sco) in ancient China. Hed founded State Ra(羅國). The name of Silla(新羅) means new State Ra, so he could become the ancestor of the people of Silla. He was the son of Zuanxu Gaoyang. State Gaya(加耶), the fatherland of Gim Yusin had been called Geumgwan-gug(金官國) which means the state of official of metal. Geumgwan was the son of Shaohao Jintian. Silla was the state of Hwagwan and the Gaya was the state of Geumgwan. Hwagwan, the founder of the royal household of Silla was the son of Zuanxu and Geumgwan, the founder of the royal household of Gaya was the son of Shaohao. Zuanxu and Shaohao was the descendants of Hwangdi, so Hwangdi was the common ancestor of Silla and Gaya. Finally Hwangdi became the same ancestor of Gim Yusin and King Muyeol(武烈王) who was the father of King Munmu. The tombstone of King Munmu and Gim Yusin manifests the union of the blood of Gim Yusin and King Muyeol. But it was not the fact but the rhetorical fiction.