• Journal of the Korean GEO-environmental Society
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• v.4 no.2
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• pp.15-25
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• 2003

Time Domain Refletometry, or TDR, is a remote sensing electrical measurement technique that has been used for many years to determine the spatial location and nature of various objects, especially in the United States of America and Australia at mining industry. Since early on 1990, the TDR techniques have been applied to the geotechnical engineering such as : deformation measurement of rock slope and landslide, monitoring of ground water content and ground water level change, investigation of ground contamination and its movement. The first application of this technique, in 1996, to the domestic area is to determine the possibility of ground settlement caused by subsidence from abandoned underground mines at the Tongri and Gosari in Gangwon-d. In this paper, through the results of analysed deformation data between conventional measurements and the TDR, it was concluded that the TDR technique is a useful instrumentation method for the prediction of ground deformation.

• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.255-276
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• 2016

This paper is designed to investigate the dynamic structure of optimal tariff imposed by the oil importing country from OPEC when OPEC increases the oil reserves through exploration and development. For this purpose, we used a Stckelberg differential game modeling approach, and tried to analyze two cases such that the one is the extraction cost is dependent on the oil reserves and the other is the extraction cost is independent of it. On the basis of this analysis, we propose that the importing contry has to impose dynamically inconsistent tariffs if the extraction cost is dependent on the oil reserves. Otherwise, she should impose dynamically consistent tariffs announced at initial time. In addition, we found that whether or not the exporting country uses some portion of oil produced for domestic consumption does not affect our policy proposition stated above.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.463-472
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• 2009

Many old domestic mines were excavated with the room and pillar method or the sublevel caving method and they involve the great possibility of surface subsidence, especially in the shallow depth mines. In most of these cases, the mine roadways and openings are very irregular in shape and the information about the local geology is uncertain. Consequently it is not simple to standardize the estimation method for the possibility of subsidence, especially the sinkhole subsidence. In this study, the fuzzy reasoning method has been applied for development of estimating the possibility of subsidence occurrence in abandoned mine area. This method has the advantage in producing the reliable estimation results with a simple performance procedure even when the precise information on the local geology and mining conditions is rare. For the verification of applicability of this method, the developed method has been applied to Kumho mine in Bonghwa, Kyungbook province and the Choong-ju mine in Iryu, Choongbook province where the surface subsidence occurred already.

• Journal of the Korean GEO-environmental Society
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• v.14 no.4
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• pp.47-52
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• 2013

In Korea, the number of mining operations are getting smaller. But buried accidents are on the increase every year. For this reason, it is important to safety management in construction process, especially the worker's safety. In the field of construction needs utilization of integration system according to purpose of utilization, particularly in underground construction sites utilizing is emphasized even more. The current element technologies of location tracking, sensors and wireless communication possible to utilize but it is still difficult to utilization of integration system in construction field because a study is not complete on commercialization and availability. In this study, for real time 3-dimensional management of ubiquitous construction site in ground and underground, measure data using MEMS sensor, EDM and DGPS in 2 test site. Also results were analysed by MATLAB. As a result, error is verification less than 3 meter that possible to distinguish with the naked eye and construct direction of study based on result of former.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.332-341
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• 2023

The controversy is becoming a hot issue after informed that the water release from Canadian oil sands tailings may initiate within a few years. The surface-mined bitumen extraction in open pit generates wastewater inevitably, which has been conveyed to store in tailings ponds. Currently, the size of tailings pond is getting seriously larger. It is known that tailings treatment is very difficult because the generation of MFT (mature fine tailings) layer is hardly processable. It would be the key process to separate solids and liquid placed within MFT where fine particles are well dispersed. In this paper, the surface-mined bitumen extraction process was first introduced, and followed by presenting the components of tailings as well as the characteristics of MFT. In addition, MFT process options were evaluated. It is expected that successful MFT treatments may be achieved by dewatering process using effective polymer flocculants in near future.

• The Journal of Bigdata
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• v.7 no.1
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• pp.1-14
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• 2022

The proof-of-work consensus algorithm used by most blockchains is causing a massive waste of computing resources in the form of mining. A useful proof-of-work consensus algorithm has been studied to reduce the waste of computing resources in proof-of-work, but there are still resource waste and mining centralization problems when creating blocks. In this paper, the problem of resource waste in block generation was solved by replacing the relatively inefficient computation process for block generation with distributed artificial intelligence model learning. In addition, by providing fair rewards to nodes participating in the learning process, nodes with weak computing power were motivated to participate, and performance similar to the existing centralized AI learning method was maintained. To show the validity of the proposed methodology, we implemented a blockchain network capable of distributed AI learning and experimented with reward distribution through resource verification, and compared the results of the existing centralized learning method and the blockchain distributed AI learning method. In addition, as a future study, the thesis was concluded by suggesting problems and development directions that may occur when expanding the blockchain main network and artificial intelligence model.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.382-389
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• 2020

Soil properties in opencast mines are a key factor in reclamation (revegetation) of mining areas. In this study we determined the soil physical and chemical properties of kaolinite tailings, reclaimed areas, and adjacent natural red pine (Pinus densiflora S. et Z.) forests in kaolinite opencast mines in Sancheong-gun, Gyeongsangnam-do. Six sites were chosen for collection of soil samples to determine soil physical and chemical properties at a soil depth of 10 cm. Soil bulk density was significantly higher (P < 0.05) in the kaolinite tailings (1.51 g·cm-3) than in the reclaimed areas (1.19 g·cm-3) and red pine forests (0.93 g·cm-3), whereas air phase in the kaolinite tailings (14.2%) was significantly lower than in the red pine forests (32.6%). Clay content in the red pine forests was significantly higher than in the reclaimed areas (18.7%) or kaolinite tailings (14.8%), whereas soil structural stability index was significantly lower in the reclaimed areas (1.61%) and kaolinite tailings (0.87%) than in the red pine forests (7.75%). Soil pH was significantly higher in the kaolinite tailings (pH 6.68) and reclaimed areas (pH 6.27) than in the red pine forests (pH 5.31). Soil organic carbon and total nitrogen were significantly higher in the red pine forests (C: 36.03 mg·g-1; N: 2.08 mg·g-1) than in the reclaimed areas (C: 5.00 mg·g-1; N: 0.31 mg·g-1) than in the kaolinite tailings (C: 2.12 mg·g-1; N: 0.07 mg g-1). The amount of available phosphorus was not significantly different among the three treatments. The concentration of exchangeable potassium was significantly lower in the kaolinite tailings (0.08 cmolc·kg-1) than in the reclaimed areas (0.21 cmolc·kg-1) and red pine forests (0.30 cmolc·kg-1). These results indicate that, because of high soil bulk density and low soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium in kaolinite tailings and reclaimed mining areas, soil nutrient management is needed in order to reclaim the vegetation in these type of areas.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.109-110
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• 2003

우리나라에서의 철도는 도로교통에 비해 수송분담율이 상대적으로 낮지만, 2001년을 기준으로 1년 동안 824만 명을 수송하여 전체 여객 수송량의 약 6.2 %를 차지하고 있다. 최근 연구결과 비도로용으로 사용되고 있는 디젤엔진이 NOx와 입자상 오염물질 배출의 주요한 오염원으로 밝혀졌다. 국내외적으로 대기오염원 중 자동차나 트럭 등 도로용 차량에서 배출되는 오염물질에 대해서는 오래 전부터 관심을 기울여 왔지만, 디젤기관차, 선박 및 경작, 건설, 벌목, 채굴 장비 등을 포함하는 비도로용 이동오염원에 의한 오염물질 배출제어에 관해서는 논의가 거의 이루어진 적이 없었다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.314-315
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• 2003

석면은 자연적으로 발생되는 광물로 1887년 캐나다의 케베크 지방에서 채굴이 시작되어 흡음, 단열, 내부식성, 내약품성이 뛰어나고 값이 싸자는 이점 때문에 90%이상이 건축재료로 사용되었다. 석면은 장기간 노출될 경우 대략 15년에서 30년의 잠복기를 거쳐 석면폐증, 폐암 악성 중피종을 등을 유발하며 단 한번 진단되면 아직 이렇다할 치료방법이 없다. 대체적으로 석면폐의 경우 질병의 발생과 석면 섬유 사이에는 양-반응관계를 보이며(Beckla ke et al., 1980) 악성중피종과 폐암의 경우는 화학적 성질과 함께 섬유의 굵기, 길이, 모양 등의 물리적 성질이 질병의 발생과 밀접한 관계가 있는 것으로 보고되고 있다(Lippmann, 1988). (중략)

• Explosives and Blasting
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• v.28 no.1
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• pp.55-62
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• 2010

Explosive welding was planed in a closed drift of a mine for its reuse. In this study, we analyzed the stabilization of roof and pillar which were expected to be affected by overpressure experienced during the continual explosive welding. Three equations, normal equation, CONWEP and DDESB, were used for the estimation of overpressure. The investigation shows that the continual use of the explosive welding in a drift may result in considerable damage on the drift.