• Resources Recycling
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• v.15 no.2 s.70
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• pp.32-36
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• 2006

Magnesium has been used as light and functional material, and its demand is increasing as a material for automobile engine and for mobile phone or notebook PC case. Fused salt electrolysis and thermal reduction are regarded as main methods for the extraction of magnesium, and choice for the method is firstly according to raw material. In this study, magnesium metal is obtained by an electrolysis of magnesium chloride. Two types of fused salt mixtures were used as electrolyte and electrolyzed at 7V with a graphite anode having the same depth, and their results were compared with each other. A mixed salt of $KCl/NaCl/MgCl_2$ was the more effective than $KCl/NaCl/CaCl_2/CaF_2/MgCl_2$ in current efficiency through the experiments at $760^{\circ}C$. Purity of the prepared magnesium metal was above 98%. Some basic data for scale-up of the magnesium electrolysis equipment, which would be necessary for a commercialization, could be obtained.

• Resources Recycling
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• v.14 no.1
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• pp.33-38
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• 2005

Worldwide magnesium market has been considerably growing recently due to adoption as light materials for automobile engines and electronic devices such as mobile phones. In this study, it is to prepare magnesium oxide, which is the first-step product in smelting of magnesium from the ore, using magnesite of Yongyanag mines in North Korea as raw ores. MgO grade of the magnesite was about 45 wt%, and SiO$_2$, CaO, Al$_2O_3$ and Fe$_2O_3$ were contained as impurities. The sample ore was crushed, classified and thermally analyzed to determine its calcination temperature. The sample of 45-75 ${\mu}m$ size was calcined at 600-900$^{\circ}C$, and effect of temperature on calcination and change of the particle shape was investigated. Optimum temperature of the calcination was about 750$^{\circ}C$, and 30 minutes was sufficient to obtain over 99% conversion. The purity of the calcined MgO was about 95 wt%.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1019-1022
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• 2015

사회적 약자인 청각장애인들의 수화통역 서비스가 대체로 만족스럽게 제공되고 있지 않다. 또한 청각 장애인수 대비 수화통역가의 부족과 일반인과의 즉각적인 소통이 어려워 일상생활에 불편함을 느끼는 청각장애인들이 많다. 이의 문제점을 착안하여 본 연구에서는 청각장애인들이 휴대할 수 있는 수화 통역기를 개발하고자 한다. 청각장애인들의 손동작을 인식할 수 있는 3D센서 립모션(Leap-Motion)을 통해 수화를 인식한다. 립모션 센서와 안드로이드 스마트폰 및 태블릿과 연결하여 손 데이터 값을 분석했다. 분석한 손 데이터 값과 특정 지화(자음, 모음)와 간단한 인사말의 수화동작을 취할 때, 트래킹되는 데이터 값을 비교하여 수화를 인식하고 수화와 인식된 지화의 자음과 모음을 글자로 완성시켜, 텍스트와 음성으로 출력한다. 또한 립모션이 부착된 하드케이스 안에 스마트기기 탈착이 가능한 실용성 있는 수화통역기 제품 개발에 대한 연구를 목표로 하고 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.421-425
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• 2018

Methanol is a clear, colorless, volatile, and poisonous liquid that is commonly used as an industrial solvent. Visual impairment is a common symptom of methanol poisoning; however, visual impairment rarely occurs after exposure through inhalation. Therefore, visual loss after methanol intoxication via respiration has rarely been reported. We report a case of visual damage associated with methanol poisoning via respiratory exposure in an industrial setting. In this case in South Korea, a 28-year-old woman who worked at a cell phone factory was admitted to the emergency department with mental changes. She had blurred vision that began two days prior, but she did not come to the hospital until she experienced mental changes. She ranked 9 on the Glasgow Coma Scale and presented with severe metabolic acidosis. So, she was admitted to intensive care, and continuous renal replacement therapy was performed. Finally, she was discharged after recovery of her mental state, but had to undergo rehabilitation for six months. Also, her visual impairment was permanent. Methanol intoxication can occur through inhalation, which is difficult to detect initially. However, treatment of methanol poisoning is time-critical. Therefore, doctors should always keep in mind that methanol intoxication may occur via respiration. If in doubt, treatment should be given as soon as possible.