• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.44-57
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• 1990

Mineralogy of clay(Napseok) deposits in Yangsan area has been studied by the methods of field investigation and laboratory works including the polarizing microscopy, X-ray diffraction, infrared spectroscopy, thermal analysis, chemical analysis by electron micro-probe and atomic absorption spectrophotometer, and electron microscopy(SEM and TEM). The Napseok ores in both the Cheonbulsan and Yongcheon deposits consist mainly of sericite, pyrophyllite and quartz, with more or less tourmaline. The high temperature minerals such as corundum and dumortierite are found in the Cheonbulsan deposit, but not in the Yongcheon deposits. Dickite, nacrite, and halloysite are found in the Yongcheon deposit, but not in the Cheonbulsan deposit. The Napseok ores of the Yukwang deposit consist of sericite posits in the Yangsan area. Occurrence, chemistry and structural features of important minerals are described. Mineralogical data of sericite such as intensity raios and chemistry also support that the Napseok deposits of both the Chenobulsan and Yongcheon mines were formed at the higher temperature than those of the Yukwang mine. Presence of sericite-dickite-pyrophyllite ores in the Yongcheon deposit also suggests the lower temperautre than in the Cheonbulsan deposit.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.272-279
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• 2008

This paper describes the development of a simple and quantitative subsidence hazard estimation method appropriate to Korean coal mines using gangway depth information only. In spite of simpleness of estimation method, this new method gives good results close to those obtained using influence function method when applying to a virtual rectangular excavation model and to a closed mine where actual subsidence occurred. Therefore, this method can be effectively applied to the identification of zones liable to subsidence over closed coal mine in Korea where the shape of extraction is very complex and usually unknown.

• Parasites, Hosts and Diseases
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• v.57 no.6
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• pp.581-585
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• 2019

Confocal laser scanning microscopy (CLSM) was used to examine archaeoparasitological specimens from coprolites associated with La Cueva de los Muertos Chiquitos (CMC) located near present-day Durango, Mexico. The eggs for 4 different types of parasites recovered from CMC coprolites were imaged using CLSM to assist with identification efforts. While some of the parasite eggs recovered from CMC coprolites were readily identified using standard light microscopy (LM), CLSM provided useful data for more challenging identifications by highlighting subtle morphological features and enhancing visualization of parasite egg anatomy. While other advanced microscopy techniques, such as scanning electron microscopy (SEM), may also detect cryptic identifying characters, CLSM is less destructive to the specimens. Utilizing CLSM allows for subsequent examinations, such as molecular analyses, that cannot be performed following SEM sample preparation and imaging. Furthermore, CLSM detects intrinsic autofluorescence molecules, making improved identification independent of resource and time-intensive protocols. These aspects of CLSM make it an excellent method for assisting in taxonomic identification and for acquiring more detailed images of archaeoparasitological specimens.

• Resources Recycling
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• v.21 no.1
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• pp.3-16
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• 2012

In order to review the technological modulus of the recycling of urban mine resources and non-ferrous smelting process in Korea, key point of recycling process, physical separation, non-ferrous smelting process, unit operation for the recycling technology, recycling process of LS-Nikko Copper and Korea Zinc were studied. Finally, metal recycling processes of the typical non-ferrous smelters in Japan such sa DOWA Holdings and JX Holdings were compared with those of LS-Nikko Copper and Korea Zinc.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2185-2191
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• 2007

The traditional sensor network is composed of the cable and the sensor of high price, when collecting a sensing data, there is a weak point which is not pliability. WSN uses the equipment of low price, it will be able to collect the data which is diverse from various node. In this paper we composed coal mining topology which used IEEE802.15.4 MAC in Korea Coal Corporation site. We proposed models for the mobility support of the work manager from the coal mining, we selected the optimum model through simulation experiments. When applying the WSN in the Korea Coal Corporation and other mines, this result can be used as a basis.

• Korean Journal of Remote Sensing
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• v.8 no.2
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• pp.105-123
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• 1992

A study was made on the feature extraction for non-metallic one deposits and their related geology using the Remote Sensing and Airborne Radiometric data. The area chosen is around the Haenam area, where dickite and Quarzite mines are distributed in. The geology of the area consists mainly of Cretaceous volcanics and PreCambrian metamorphic. The methods applied are study on the reflectance characteristics of minerals and rocks sampled in the study area, and the feature extraction extraction of histogram normalized images for Landsat TM and Airborne Radiometric data, and finally evaluation of applicability of some useful pattern recognition techniques for regional lithological mapping. As a result, reflectances of non-metallic minerals are much higher than rock samples in the area. However, low grade dickites are slightly higher than rock samples, probably due to their greyish colour and also their textural features which may scatter the reflectance and may be capable of capturing much hychoryl ions. The reflectances of rock samples may depend on the degree of whiteness of samples. The outcrops or mine dumps in the study area were most effectively extracted on the histogram normalized image of TM Band 1, 2 and 3, due to their high reflectivity. The Masking technique using the above bands may be the most effective and the natural colour composite may provide some success as well. The colour composite image of PCA may also be effective in extracting geological features, and airborne radiometric data may be useful to some degree as an complementary tool.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.75-89
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• 2017

Sinkholes are key karst landforms that primarily evolve through the dissolution of limestone, and it posing a significant threat to roads, buildings, and other man-made structures. This study aims to analyze the area susceptible to sinkhole development using GIS and to identify potential danger area from sinkholes. Eight sinkhole related factors (slope angle, distance to caves, distance to faults, bedrock lithology, soil depth, drainage class, distance to mines, and distance to traffic routes) were constructed as spatial databases with sinkhole inventory. Based on the spatial database, sinkhole susceptibility maps were produced using nearest neighbor distance and frequency ratio models. The maps were verified with prediction rate curve and area under curve. The result indicates that the nearest neighbor distance and frequency ratio models predicted 95.3% and 94.4% of possible sinkhole locations respectively. Furthermore, to identify potential sinkhole danger area, the susceptibility map was compared with population distribution and land use map. It has been found that very highly susceptible areas are along Osipcheon and southeast southwest part of Hajang-myeon and south part of Gagok-myeon of Samcheok-si. Among those areas, it has been identified that potential sinkhole danger areas are Gyo-dong, Seongnae-dong, Jeongna-dong, Namyang-dong and Dogye-eup. These results can be useful in the aspects of land use planning and hazard prevention and management.

• Structural Engineering and Mechanics
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• v.6 no.3
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• pp.305-325
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• 1998

A method that determines the minimum stiffness of baracing to achieve non-sway buckling conditions at a given story level of a multi-column elastic frame is proposed. Condensed equations that evaluate the required minimum stiffness of the lateral and torsional bracing are derived using the classical stability functions. The proposed method is applicable to elastic framed structures with rigid, semirigid, and simple connections. It is shown that the minimum stiffness of the bracing required by a multi-column system depends on: 1) the plan layout of the columns; 2) the variation in height and cross sectional properties among the columns; 3) the applied axial load pattern on the columns; 4) the lack of symmetry in the loading pattern, column layout, column sizes and heights that cause torsion-sway and its effects on the flexural bucking capacity; and 5) the flexural and torsional end restrains of the columns. The proposed method is limited to elastic framed structures with columns of doubly symmetrical cross section with their principal axes parallel to the global axes. However, it can be applied to inelastic structures when the nonlinear behavior is concentrated at the end connections. The effects of axial deformations in beams and columns are neglected. Three examples are presented in detail to show the effectiveness of the proposed method.

• Membrane and Water Treatment
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• v.1 no.4
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• pp.231-251
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• 2010

The sulfatation of chitosan, by reaction with chlorosulfonic acid under controlled conditions, allowed increasing the pH range of chitosan solubility. The biopolymer was characterized using FTIR and $^{13}C$-NMR spectroscopy, elemental analysis and titration analysis and it was tested for mercury recovery by polymer enhanced ultrafiltration (PEUF). In slightly alkaline conditions (i.e., pH 8) mercury recovery was possible and at saturation of the polymer the molar ratio $-NH_2$/Hg(II) tended to 2.6. Polymer recycling was possible changing the pH to 2 and the polymer was reused for 3 cycles maintaining high metal recovery. The presence of chloride ions influences metal speciation and affinity for the polymer and "playing" with metal speciation allowed using the PEUF process for mercury separation from cadmium; at pH 11 the formation of hydroxo-complexes of Hg(II) limits it retention. Cake formation reveals the predominant controlling step for permeation flux.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.481-492
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• 2019

Due to the underground openings, the tangentially concentrated stress of the tunnel remains larger at excavation boundary and decreases toward the interior of the surrounding rock with a certain gradient. In order to study the effect of different gradient stress on rockburst, the true-triaxial gradient and hydraulic-pneumatic combined test apparatus were carried out to simulate the rockburst processes. Under the different gradient stress conditions, the rock-like specimen (gypsum) was tested independently through three principal stress directions loading--fast unloading of single surface--top gradient and hydraulic-pneumatic combined loading, which systematically analyzed the macro-mesoscopic damage phenomena, force characteristics and acoustic emission (AE) signals of the specimen during rockburst. The experimental results indicated that the rockburst test under the gradient and hydraulic-pneumatic combined loading conditions could perfectly reflect the rockburst processes and their stress characteristics; Relatively high stress loading could cause specimen failure, but could not determine its mode. The rockburst under the action of gradient stress suggested that the failure mode of specimen mainly depended on the stress gradient. When the stress gradient was lower, progressive and static spalling failure occured and the rockburst grades were relatively slight. On the other hand, shear fractures occurred in rockbursts accounted for increasingly large proportion as the stress gradient increased and the rockburst occurred more intensely and suddenly, the progressive failure process became unconspicuous, and the rockburst grades were moderate or even stronger.