• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.512-519
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• 2004

Hybrid barriers using reduction and immobilization were tested to remediate the groundwater contaminated with multi-pollutants in this study. Iron filings and HDTMA(hexadecyltrimethylammonium)-bentonite were simulated in columns to assess the performance of hybrid barriers for remediation of trichloroethylene(TCE)-contaminated water. TCE reduction rate for the mixture of iron filings and HDTMA-bentonite was about 7 times higher than that for iron filings, only suggesting the reduction of TCE was accelerated when HDTMA-bentonite was mixed with iron filings. TCE reduction rate for the two layers of iron and HDTMA-bentonite was nearly similar to that for iron filings alone, but the partition coefficient($K_d$) for the two layers was 4.5 times higher than for that iron filings only. TCE was immobilized in the first layer with HDTMA-bentonite, and then dechlorinated in the second layer with iron filings. HDTMA-bentonite may contribute to the increase in TCE concentration on iron surface so that more TCE can be reduced. Also, TCE removal in the hybrid barriers was not affected by chromate and naphthalene while the reduction rate of TCE with the co-existing contaminants by iron filings was significantly decreased. Significant TCE removal in this research indicates that the proposed hybrid barrier system has the potential to become the effective remediation alternative during the occurrence of oil shock. Also, if subsurface environments are contaminated with multi-pollutants that contain non-reducible compounds as well as reducible compounds such as TCE, the conventional reactive barriers cannot be applied to this subsurface environment, while the proposed hybrid system can be applied successfully.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.56-64
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• 2015

Acid mine drainage occurrence is a serious environmental problem by mining industry, it usually contains high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of the greatest concern. An indigenous plant extract was used to produce calcium carbonate from Canavalia ensiformis as effective biomaterial, and its ability to form the calcium carbonate under stable conditions was compared to that of purified urease. X-ray diffraction and scanning electron microscopy were employed to elucidate the mechanism of calcium carbonate formation from the crude plant extracts. The results revealed that urease in the plant extracts catalyzed the hydrolysis of urea in liquid state cultures and decreased heavy metal amounts in the contaminated soil. The heavy metal amounts were decreased in the leachate from the treated mine soil; 31.7% of As, 65.8% of Mn, 50.6% of Zn, 51.6% of Pb, 45.1% of Cr, and 49.7% of Cu, respectively. The procedure described herein is a simple and beneficial method of calcium carbonate biomineralization without cultivation of microorganisms or further purification of crude extracts. This study suggests that crude plant extracts of Canavalia ensiformis have the potential to be used in place of purified forms of the enzyme during remediation of heavy metal contaminated soil.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.2
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• pp.137-140
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• 2015

Neurofibroma is characterized as a benign, slow growing neoplasm, originating from Schwann cells or fibroblast in peripheral nerve sheaths. It may appear as a solitary tumor or have multiple localizations in von Recklinghausen disease. They are commonly found in the gastrointestinal tract and laryngeal neurofibromas are extremely rare, accounting for only 0.03 to 0.1% of benign tumors of the larynx. The aryepiglottic fold and arytenoid are the common site of occurrence for laryngeal neurofibroma, because the branch of the superior laryngeal nerve is involved. We present a case of solitary plexiform neurofibroma arising from the laryngeal surface of epiglottis in a 55-year old female who found the lesion incidentally. We removed the tumor completely by transoral laser surgery and no recurrence was found after 7 months. The case of solitary neurofibroma arising from laryngeal surface of epiglottis has not been reported in Korea. We report this case regarding the diagnosis and treatment with review of literatures.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.6
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• pp.229-238
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• 2018

The rapid response of disaster accidents can be archived through the organical involvement of various disaster and safety control agencies. To define the terminology of disaster safety is essential for communication between disaster safety agencies and well as announcement for the public. Also, to efficiently construct a word dictionary of disaster safety terminology, it's necessary to define the priority of the terms. In order to establish direction of word dictionary construction, this paper compares the usage of disaster safety terminology by media: word dictionary, new media, and social media, respectively. Based on the terminology resources collected from each media, we visualized the distribution of terminology according to frequency weights and analyzed co-occurrence patterns. We also classified the types of terminology into four categories and proposed the priority in the construction of disaster safety word dictionary.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.97-104
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• 2012

Recent climate change has increased the occurrence of flood disaster. There are two approaches to prevent flooding damage. One is a structural method and the other is a non-structural method. The production and usage of a flood risk map are the example of non-structural way. The flood risk map displays several kinds of information to minimize casualties and property damage caused from flooding. In order to increase the usage of current flood risk maps and improve intuitive recognition of flood information, this paper produced flood risk maps based on geo-spatial information system using three dimensional virtual reality techniques and investigated the applicability of the maps. Because flood information is easily accessed through online, flood risk maps suggested in this paper are regarded as an efficient tool.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.13-22
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• 2015

Developed ground cavity due to leakage of decrepit old sewer pipe causes ground surface settlement and brittle fracture of pavement. Recently, for 5 years, frequency of occurrence of ground subsidence phenomenon tends to increase rapidly and/or steadily. It is difficult to investigate ground surface settlement and/or subsidence in urban area because most ground surfaces are covered with asphalt or concrete pavement. In this research, therefore, ground surface settlement, influence zone and settlement of sewer pipe were analyzed using finite element method. Not only reinforced effect of pseudo-plastic backfill that is applied to prevent ground surface settlement or subsidence spot, was compared and analyzed using numerical analysis program, but also direct shear test was carried out to determine strength parameters of pseudo-plastic backfill.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.332-343
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• 2007

This study aims to examine the distribution of heat waves and to understand its cause for 33 years$(1973\sim2005)$ from 60 weather stations in Korea. Heat wave is defined as a period of 3 or more days with a daily maximum temperature exceeds the 95th percentile. In the inland of Chungcheong region, the Chungcheong western costal region, the inland of Jeolla region, the inland of Gyeongsang region and the southern region of Jeju island, heat wave days appeared more than 160 days. In the middle region of eastern costal and the northern region of Jeju island, heat wave days were less than 110 days. In regions that were heavily influenced by southwesterly winds during the occurrence of heat waves, such as the inland of Chungcheong region, the Chungcheong western costal region, the inland of Jeolla region and the inland of Gyeongsang region, heat waves continued for the longer term.

• Safety and Health at Work
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• v.11 no.2
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• pp.127-135
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• 2020

A safe work environment is crucial in high-risk industries, such as construction refurbishment. Safety incidents caused by uncertainty and unexpected events in construction refurbishment systems are difficult to control using conventional safety management techniques. Resilience engineering (RE) is proposed as an alternative to traditional safety management approaches. It presents a successful safety management methodology designed to deal with uncertainty in high-risk work environments. Despite the fact that RE resides in the safety domain, there is no common set of RE indicators to measure and assess resilient in the work environment. The main aim of this research is to explore RE indicators that have been identified as important in developing and assessing the resilient work environment in high-risk industries, particularly in construction refurbishment. Indicators have been attained through a systematic literature review of research and scholarly articles published between the years 2004 and 2019. The literature review explored RE indicators in various industries. Descriptive analysis and co-occurrence-based network visualization were used for data analysis. The findings revealed 28 RE indicators in 11 different high-risk industries. The results show that the four commonly used indicators were: top-management commitment, awareness, learning, and flexibility, all of which have a strong relationship with RE. The findings of this study are useful for stakeholders when making decisions concerning the most important RE indicators in the context of their research or practice as this would avoid the ambiguity and disparity in the identification of RE indicators.

• Journal of the Speleological Society of Korea
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• v.59
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• pp.21-36
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• 1999

Most scholars calssify caves into natural resource, but caves possess values of natural and human resource, mix up the features of natural resources and human resources. Now, caves are distributed 260 in Korea. Seongryu Cave is showed in 1967 for the first time, till 1997 12 caves is opened to tourist. But since 1996 the 12 show caves of all is not launched the safety and environment-protection check-up adduced reason for IMF. Then caves must maintain environment of the normal temperature, humidity and dark. But the environment of caves are destroyed by tourism development. Thus to maintain environment of caves, it used to consider the counterplan as follows in restraint of the environmental change. Firstly, in case of development work to open caves, it must keep up with the prototype. Secondly, it must establish a freight depositary to prevent the influence of the caves's stain and damage due to tourist's objects. Thirdly, to maintain the normal temperature and humidity, it must install artificial poultice equipment of the inner parts of caves. Fourthly, in order to prevent the occurrence of $CO_2$, it must assessment of the optimum number of the greatest stayer. Fifthly, the control of closure for a given period of time is useful of the restoration to the cave's original state. Sixthly, by means of make narrow entrance, it should not influence the outer's air on the inner parts on caves. Seventhly, to keep the temperature of the inner part of caves, the lightening should be maintained moderately considering the convenience of a tour. Eightly, when water-proof cables for the lightening bulbs are connected each other, silicon tape is suitable and circuit breakers should be installed at the diverging points of the cables. Ninthly, the direction and angle of the lightening must be changed periodically to prevent green-pollution at the lightening spot. Lastly, when facilities and arrangements are equipped, corrosive materials should be excluded if circumstances allow.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.233-252
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• 2015

This research are systematic and scientific approaches to obtain the distribution, occurrence and quality of granite stone for building purposes. The process of dimension stone exploration must be carried out to know the underground potentiality of granitic body using the basic data collection and study, field mapping, detailed drilling survey, televiewer technique, and physical and chemical tests in the Geochang area. Televiewer data obtained in drilling boreholes can be accurately distinguished from the discontinuous face, strike and inclination, extension which is difficult to obtain in a core logging. 3D joint images will be helpful to establish a quarry exploitation plan because the 3D joint images give quite accurate information down to depth below the outcrop surface. Through the process of the quality estimation on the Geochang site, the proven reserve estimated as dimensional building stone are calculated with good quality in petrologic and physical properties.