• The Journal of Engineering Geology
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• v.31 no.4
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• pp.523-532
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• 2021

The treatment of acid rock drainage was reviewed and evaluated for the case of pyrite rocks distributed in a highway embankment. During the highway's construction, neutralization using alkaline water repellent was applied to the embankment section to prevent acid rock drainage. However, it still occurred long after the construction was completed owing to rain infiltration, and the acid rock drainage polluted the surrounding soils and streams. To solve this problem, treatment facilities such as SAPS (Successive Alkalinity Producing Systems) or ecological wetlands and sand filtration were installed. After the installation of the treatment facilities, the effluent and soils contaminated by acid rock drainage nearby the outlet of the facilities were analyzed and evaluated for a period of years. Measurements of the pH of the effluent and analysis of the heavy metal contamination of the soils confirmed that the neutralization treatment for acid rock drainage is being performed properly and that contamination of heavy metals in the acid rock drainage is also being stably controlled by the treatment facilities.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.525-531
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• 2021

The importance and utilization of underground spatial is increasing due to urban concentration. And so underground spatial information is being built. Because underground spatial information is an important NSDI (National Spatial Data Infrastructure), the accuracy and performance of underground spatial exploration devices used for construction are managed separately. In accordance with the laws and regulations related to spatial information, the government is conducting performance tests for underground facilities surveying equipment. The current performance test site mainly targets metal pipelines, and there is no absolute position surveying inspection system. In this study, test bed model for performance inspection of underground space exploration equipment was presented. The test bed presented in this study can be used as a test site to supplement the limitations of the existing domestic test bed and to verify the performance of the latest equipment.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.195-209
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• 2012

1) 버섯종균 생산 시스템 개선 버섯의 품질과 수량을 좌우하는 주요 요인은 종균의 활력이다. 그러나 말라위에서는 종균의 활력이 낮아 조그마한 350cc 음료수 병에 배양 완성하는데 20일이 소요되는 등 노동력의 비효율성을 개선하였다. 따라서 350cc 병을 3500cc 비닐봉지로 개선하여 입봉하는데 소요되는 시간을 10배 이상으로 단축 개선하였다. 또한 곡립종균을 액체종균으로 대처한 결과 균사생장 속도가 빨랐으며 작업속도가 빨라졌다. 곡립 수수를 밀로 대체하여 종균제조 노동력을 효율적으로 전환하였다. 2) 버섯재배사 환경관리 개선 버섯재배의 4대 환경조건은 온도, 습도, 환기, 광이다. 그러나 말라위의 버섯재배사는 4대 환경조건 조절을 자연상태에 의존하고 있다. 그럼에도 불구하고 비닐로 커버된 상태에서 문을 닫아두어 과습이 되고 환기가 되지않았다. 이를 개선하기 위하여 직경 5cm 환기공을 버섯재배사 당 4개씩 만들도록 지도하였다. 3) 버섯배지 개선 말라위에서는 옥수수 대를 잘라 버섯배지로 주로 이용하고 있다. 이를 개선하여 말라위 북부지역(다광)에 대규모 사탕수수 공장을 방문하여 사탕수수 박을 이용하여 버섯재배 기술을 교육하였다. 이를 이용함으로서 버섯 균사생장속도를 빠르게 하고 균사량의 축적을 높이도록 하여 고품질 다수확하는데 교육을 하고 컨설팅을 실시하여 개선하였다. 4) 버섯 배지 야외발효 후 지면재배 시도로 시간 단축과 비용절감 말라위 버섯배지 혼합제조법은 옥수수대 한가지로서 영양원이 없다. 이를 개선하여 배지를 수분을 흡수시킨 후 야외 퇴적하므로서 배지의 물리성을 개선하고 야외발효 과정 중 양분이 합성되어 양질의 배지를 만드는 방법이다. 야외발효한 배지를 봉지에 담아 균상에 입상하는 불편함과 나무로 만들어진 균상대의 과습으로 인한 곰팡이 발생과 개미 침입으로 썩는 것 등을 방지하기 위하여 지면재배 방법으로 개선하였다. 이 지면재배는 균상 만드는 나무재료와 인건비 절감. 병해충 발생 방제 뿐만아니라 고품질 다수확할 수 있는 방법으로 개선 교육과 시범 시연을 실시하였다.

• Journal of the Korean Geotechnical Society
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• v.26 no.4
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• pp.59-68
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• 2010

Piping, a common form of internal embankment erosion, is caused by progressive movement of soil particles through an embankment. The phenomenon commonly occurs with precursory signs of development of fractures in dam structures, but also occurs without any noticeable signs in dams that showed satisfactory dam performance for several years, due to dissolution of soluble material in an embankment. While piping accounts for nearly 50% of the causes for dam failure, few studies have been made for systematic evaluation of the phenomenon. In this study, we attempted to monitor the changes in electrical resistivities of fill-dam material while a saddle dam is dismantled for the construction of emergency spillways of Daechung dam. Two artificial subhorizontal boreholes were drilled into the embankment structure to simulate piping along the two artificial flow channels. Monitoring of changes in electrical resistivity showed an increase in resistivity values during piping. Thus, the investigation of resistivity over time could be an effective method for piping prediction.

• Journal of the Korean Geotechnical Society
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• v.26 no.9
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• pp.59-69
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• 2010

This study is experimentally investigated for characteristics of lightweight air-trapped soils with uniform quality. Previously, EPS (Expanded PolyStyrene) blocks are often used as lightweight embankment, but many problems such as the level difference and cracks were caused by plastic (creep) deformation. So, a new material development is urgent. By means of alternatives, lightweight air-mixed soil using in-situ soils has been developed and applied to fields. In comparison with EPS block, lightweight air-mixed soil has less plastic (creep) deformation in long period, but the strength characteristics are different according to the soils where they are obtained. Therefore, the quality management of lightweight air-mixed soil is very difficult. Therefore in this study, characteristics of lightweight air-trapped soil using a manufactured sand with uniform quality are investigated. To found out the compression and tensile characteristics of lightweight air-tapped soils, unconfined compression test and splitting tensile test are conducted on the specimens prepared with different unit weight, cement-sand ratio and air-pore.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.1
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• pp.21-31
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• 2023

Purpose: This study aimed to investigate the effects of mental health factors on oral symptoms and the relationship between the two in Korean adolescents. Materials and Methods: Raw data of 54,948 Korean adolescents among the participants of the 17^th Korean Youth Health Behavior Survey conducted in 2021 by the Korea Disease Control and Prevention Agency were analyzed in this study. Results: Mental health factors evaluated in this study included sadness and despair, suicidal thoughts, suicide attempt, loneliness, stress, depression, and anxiety. Our findings showed that all mental health factors were associated with oral symptoms. Particularly, factors affecting dental pain were suicidal thoughts, stress, anxiety, loneliness, depression, sadness, and despair. Further, all mental health factors affected ulorrhagia. Conclusion: In conclusion, the findings in this study are expected to contribute to the development of programs for the intervention of key mental health factors affecting oral symptoms to improve overall health in Korean adolescents.

• Conservation Science in Museum
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• v.3
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• pp.37-42
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• 2001

The Stone Lamp from Hyeon Hwa Temple is an important piece of buddhist art from the Koryo Dynasty (initiated by King Hyun-Joung). It provides an insight into stone-art techniques employed during the Koryo Dynasty, and serves as an authentic example of work from that period, which had both a refined style and artistic integrity. However, the stone lamp was dismantled and has been stored at the National Museum of Korea since 1986. This was because it was severely damaged, as a result of exposure to an outdoors environment. This article discusses the conservation of the stone lamp, which was carried out by conservators at the National Museum of Korea. It was prepared for a new display of the lamp to the public. The conservation process can be briefly described as follows: Cleaning (this includes the removal of previous repairs that were made), the re-attachment of the object's original fragments, and the gap-filling of missing parts. After its conservation, the object is in a much better condition and ready to be displayed once more. What is more important, in terms of the long term preservation of the stone lamp, is that the condition of the stone lamp needs to be continuously monitored, and appropriate conservation actions should be taken as necessary.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.153-155
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• 2021

A large amount of combustible household waste are incinerated on a large scale. Incineration ashes including flooring and scattering materials are generated in the incineration facilities. The incineration materials (flooring and scattering) are generated 16.5% of the total amount ashes brought into the incinerator. The amount of incineration materials decrease the landfill period of existing landfills and increase the needs for the construction of new landfills. This study introduces technical and institutional suggestions to solve increasing incineration ash problem by recycling them. As a technical recycling method, incineration materials can be recycled by producing earthwork materials and concrete products. In addition, the government and local governments will be able to promote recycling by improving related laws such as the Waste Management Act and by preparing active institutional support measures such as incentives for recycling companies for Green New Deal strategies.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.83-83
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• 2022

유채(Brassica napus L.)는 가을에 파종하여 이듬해에 초여름에 수확하는 겨울작물로 종실 수량이 많고 종자의 조지방 함량이 높아 주로 기름을 생산하기 위해서 재배되고 있다. 우리나라에서 유채는 경관을 목적으로 주로 재배되며 면적은 약 5,000ha 정도 재배되고 있다. 최근에는 유채유 생산을 목적으로 전남 등 남부지방에서 재배면적이 증가하고 있다. 유채유의 대량 생산을 위해서는 재배과정의 생력기계화에 유리한 논 재배가 주로 이루어지고 있다. 따라서 유채의 육종은 논 재배 적응성이 뛰어나며, 벼와의 작부가 가능하며 봄 파종 재배가 가능한 조숙품종의 육성이 필요하며, 식용유로 이용이 가능한 지방산 조성이 우수한 품종의 육성도 필요하다. 본 연구는 농촌진흥청 농업유전자원센터에서 보유하고 있는 유채 유전자원 350점을 대상으로 작물학적 생육특성을 평가하였고 종자를 수확한 후 지방산 조성을 분석하였다. 생육특성은 경장 등 12항목을 유채 유전자원 특성조사 및 관리요령(RDA, 2011)을 기준으로 조사하였다. 가을에 파종하여 재배할 때 개화소요일수는 파종 후 137일부터 210일까지 소요되었으며, 봄 파종 재배 시에는 파종 후 65일부터 150일까지 개화가 진행되었고 개화가 되지 않은 계통이 67계통이었다. 경장은 85 ~ 211cm, 수장은 28 ~ 79cm, 분지수는 5 ~ 21개, 수당 협수는 29 ~ 106개, 협당 종자수는 18 ~ 35개 및 협장은 2.7 ~ 8.8cm로 다양하였다. 유채 유전자원의 지방산 중 올레산과 에루스산 함량은 각각 9.7 ~ 70.4% 및 0 ~ 54.7% 범위였다. 공시계료 중 IT 279089 등 3자원은 개화기가 빨라 조생종 육성에, IT279125 등 3자원은 올레산 함량이 68%이상으로 양질 지방산 품종 육성재료로 활용할 예정이다.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.39-45
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• 2024

The residual alveolar ridge below the denture base undergoes physiologic changes over time, which results in the existing dentures becoming less accurate with the residual alveolar ridge. In addition, changes of the occlusal plane, decreasing in vertical dimension and loss of denture retention and facial support can occur. Consequently, denture relining may be required to accommodate these changes and ensure an ongoing close fit. Relining a denture can be performed directly on the chairside using autopolymerizing relining materials or indirectly in the laboratory using heat-cured relining materials. A direct relining method is not only simple but also time and cost effective. However, irritation or burning sensation of the mucosa can occur, and poor bonding of the relining material to the denture base can be cited as disadvantages. The indirect relining method exhibits relatively high bonding strength between the relining material and the denture base, but the patient might experience discomfort during relining process period. This report will examine the characteristics of relining materials, including those used in the relining of CAD-CAM dentures, and explore the clinical considerations for relining procedures.