• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1867-1872
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• 2010

본 연구에서는 1980년부터 2008년까지의 재해역학조사센터(http://www.emdat.be/)의 자료를 활용하여, 북한지역의 홍수로 인한 피해를 조사하였다. 북한의 홍수 발생 기간 중 약 70%가 주로 7월과 8월에 발생하였으며, 홍수로 인한 총 재산피해는 약 180억 달러에 달한다. 이중 1995년의 홍수는 약 150억 달러로 세계 50대 자연재해로 기록되었다. 또한, 2007년의 홍수는 북한의 자연재해 중 가장 많은 인명피해로 당시 사망자는 600명 이상이 기록되었다. 북한의 홍수 유형별 피해 규모를 분석하기 위하여 홍수 유형을 불특정 홍수, 돌발 홍수, 일반 홍수로 분류하여 분석하였다. 또한, 남북한의 차이를 분석하기 위하여 남한의 홍수 사례를 같은 유형으로 분류하여 함께 비교하였다. 유형별 빈도는 남한의 경우 3가지 유형이 비슷한 빈도로 발생된 반면, 북한의 경우 일반홍수의 빈도가 다른 홍수의 빈도 보다 조금 많이 발생하였다. 유형별 인명피해 부분에서는 남한은 전체 유형에서 돌발홍수가 52%로 가장 많은 부분을 차지했으며, 북한의 경우는 일반홍수가 42%로 가장 많이 차지하였다. 결론적으로 남한은 일반홍수와 돌발홍수의 빈도는 같았으나, 돌발홍수가 인명피해 면에서 2.3배 많이 발생하였으며, 북한의 경우 불특정 홍수와 돌발홍수의 발생 빈도는 같았으나, 돌발홍수로 인한 인명피해가 1.5배 많이 발생하였다. 경제적 피해 부분에서는 남한의 경우 돌발홍수가 약 19억 달러로 가장 많은 피해액을 발생시켰으며, 북한의 경우 일반홍수가 약 153억 달러로 가장 많은 피해액을 발생시켰다. 이는 남한의 약 7배에 해당하는 금액이다. 남북한이 경제적 피해 부분에서 큰 차이를 보이는 것은 1995년의 대홍수의 피해액이 약150억 달러로 기록되었기 때문으로 사료된다. 향후 기후변화로 인하여, 자연재해는 더욱 증가할 것으로 생각된다. 남한의 연구뿐만 아니라 한반도 전체에 대한 연구가 필요하다. 현재, 북한의 경우 기상 현상, 재해정보 등의 연구 자료는 남한 지역의 연구에 비해 상대적으로 많이 부족하며, 매우 제한적이고 단편적인 자료들만 존재하고 있다. 따라서 이에 관한 많은 연구들이 필요한 실정이다. 현재 작성되어 있는 북한의 재해 취약성 지도를 좀 더 연구하여, 한반도 전체의 재해 취약성 지도의 작성이 필요할 것으로 생각된다. 또한, 한반도 지역에서 발생하는 위험기상에 따른 사회경제적 피해를 줄이고 능동적으로 대처하기 위해 남북간 기상협력이 활성화 될 필요가 있을 것으로 생각된다.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.37-41
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• 2000

This study has been carried out to investigate the chemical composition of Acorus calamus L., a wild plant (Chang Po) which has long been used as a medicine or a hair rinse in Korea and China. Potassium was found to be the most predominant mineral in leaf and root, followed by calcium, magnesium, and phosphorus, in a decreasing order. Contents of potassium in leaf and root account for 54a.65 mg% and 242.87 mg%, respectively. Contents of these minerals in leaf were higher value than that in root. Glucose and fructose were found to be the major free sugars in leaf and root. Malic acid was the most abundant organic acid of leaf and root, and followed by citric acid. Fourteen different kinds of fatty acids were identified from the leaf and root. Content of unsaturated fatty acids. such as linolenic, and linoleic acid ware higher than that of saturated fatty acids. Content of total amino acids was 3 times higher in leaf than that in root. Leucine was the major amino acid in leaf and glutamic acid in root.

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.39-45
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• 2011

This study presents the thermal behaviors of glass beads-rubber mixtures depending on the volumetric fraction of each constituent and relative size between them. The transient plane source method is used to measure the effective thermal conductivity of mixtures. The discrete element method (DEM) and the thermal network model are integrated to investigate the particle-scale mechanism of heat transfer in granular packings. Results show that 1) the effective thermal conductivity decreases as the rubber fraction increases, and 2) the relative size between two solid particles dominates the spatial configuration of inter-particle contact condition that in tum determines the majority of heat propagation path through particle contacts. For the mixtures whose volumetric fraction of rubber is identical, the less conductive materials (e.g., rubber particles) with a large size facilitate heat transfer in granular materials. The experimental results and particle-scale observation highlight that the thermal conduction behavior is dominated not only by the volumetric fraction but also the spatial configuration of each constituent.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.53-63
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• 2011

In this study, a composite behavior of stone columns reinforced in a soft ground, Sabkha, has been evaluated by performing a series of field measurements and numerical analyses. Field load tests were performed to verify the effect of the composite ground reinforced by stone columns in Kayan, Saudi. The settlement measured in the field test was compared with the settlement calculated by the Priebe method and the numerical analysis using ABAQUS. It is found that the settlement estimated using the Priebe method significantly overestimated the settlement measured in the field test. In addition, it is confirmed that consideration of confining effect exerted by surrounding adjacent stone columns in a numerical simulation is indispensable to estimate accurately the settlement of stone column composite ground.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.467-470
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• 2009

A traumatic pulmonary pseudocyst is a rare complication of blunt thoracic trauma. The clinical symptoms and signs are similar to other respiratory diseases, such as pulmonary tuberculosis. Therefore, a trauma history with the resulting radiologic and clinical findings is important for making a diagnosis. A 26-year-old male was admitted to our hospital due to cough for 3 days. The chest x-ray revealed diffuse infiltrations and a cavitary lesion at the left lung. His left chest had hit a tree as a result of motorcycle accident one day before admission. Initially, it was assumed that his symptoms and chest X-ray might be due to a tuberculosis infection. However, bronchoscopy revealed old blood clots at both lungs, particularly in the left lower lobe bronchus. A transbronchial lung biopsy showed alveolar hemorrhage. A traumatic pulmonary pseudocyst was diagnosed from his trauma history and these findings. Computed tomography of the chest performed 4 months later showed regression of the cavitary lesion.

• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.897-901
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• 2003

The sulfating reaction of coal fly ash with ammonium sulfate and the microwave extraction of aluminum ions from the resultant materials using sulfuric acid have been investigated. The (NH$_4$)$_3$Al(SO$_4$)$_3$ formed by the reaction of coal fly ash and ammonium sulfate decomposed to NH$_4$Al(SO$_4$)$_2$ at $\geq$ 350$^{\circ}C$. The maximum efficiency of aluminum ions extracted from the sulfating reaction product (400$^{\circ}C$, 120 min) by microwave heating (90$^{\circ}C$, 240 min) using 1 M H$_2$SO$_4$ was 84％ (based on Al content in coal fly ash) but 77％ by conventional heating at same condition.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.41-48
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• 2015

The performance characteristics of a scroll expander is the most important variable for the performance of organic Rankine cycle system. In this paper, the performance characteristics of a scroll expander was identified using 1kW class organic Rankine cycle system with various operating conditions. The ORC system is composed of an evaporator, a scroll expander, a condenser and a working fluid feed pump that uses R245fa as working fluid. The hot water temperature was controlled from $80^{\circ}C$ to $115^{\circ}C$ by the 50kW-class electric water-heater. The maximum isentropic efficiency of the scroll expander was measured about 77%, and the shaft power was measured from 0.5 kW to 1.8 kW according to heat source temperatures.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.1
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• pp.12-22
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• 2012

In Seoul, skyscrapers are built in commercial zones known as residential-commercial complexes, which cause such environmental problems as urban heat islands(UHI) and air pollution. To investigate air temperature differences in areas near skyscrapers at Gangnam-gu, Seoul, South Korea, fixed air temperature observation and traverse observations were performed from March 16, 2008 to March 15, 2009. The annual mean air temperature at Tower Palace(TPL) was higher than that at Sookmyung Girls' High School(SMG) by $0.7^{\circ}C$, although the distance between the two observation positions is only 200m. The number of tropical nights at TPL was 13, while that at SMG was 5. The higher air temperature at TPL was due to a significantly lower sky view factor(SVF), which prevented long-wave radiation from emitting into the sky. The highest air temperature increases near TPL occurred on summer nights because of the high-electricity consumption value of $70.22Wh/m^2$ for the TPL block in August due to air conditioning for cooling. It is concluded that the warm air pocket centered on TPL.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.357-363
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• 2005

When typhoon approaches, ship normally drops her anchor at proper anchorage for sheltering. If an anchored ship is under the influence of typhoon, she can keep her position when the external force and counter force is balanced. Where, external force is induced by wind, wave and tidal currents while counter force is induced by holding power of anchor/chain and thrust force of main engine. In this study, authors presented a method to analyze theoretically the limit of external force for the ship to keep her position without being dragged and, to check the validity of the method, applied this to the ship which had been anchored in Jinhae Bay when the typhoon MAEMI passed on September 2003.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.311-317
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• 2010

Mobile Harbor(MH) is a new paradigm for maritime transport system introduced in Korea, the target of which is to carry out ship-to-ship cargo operation rapidly and effectively even under a condition of sea state 3. A MH ship is moored alongside a large container vessel anchored at the defined anchorage and also equipped with gantry cranes for handling containers. The MH study concerned includes rapid container handling system, optimum design for floating structure, hybrid berthing & cargo operation system, design for cargo handling crane, etc. This paper is to deal with a conceptual design of a stabilized mooring system and mooring equipment under a condition of ship-to-ship mooring. In this connection, we suggest a positioning control winch system in order to control heave motions of the MH ship which is to add constant brakepower and stabilized function to an auto-tension winch and mooring equipment used currently in large container ships.