• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.104-135
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• 2016

This paper aims to consider history and value of the Mingshansi Grottoes, a complex of Buddhist rock sculptures in Anyue County, Sichuan Province, China. Mingshansi Shiku, not that far from Baodingshan Grottoes at Dazu District, Chongqing City, is an important art work of Liu Benzun sect. Even though there are not many niches and sculptures in the Mingshansi Shiku, it was designated as a Major Historical and Cultural Site Protected at the National Level due to its large scale and highly valued art works in it. In the Mingshansi Grottoes there is not any information inscribed on the rockface about when the grottoes were established. Because a stone pagoda, which had information about when and by whom they were established, was collapsed, some scholars considered them to be made in North Song or early Southern Song Dynasties based only on the artistic style of sculptures of the grottoes. The School of Archaeology and Museology at Peking University recently carried out a survey documenting the Mingshansi Grottoes, and thereby the school gives an important material for studying the grottoes. The grottoes consist of a Dharma-protection Warrior niche, a statue of Guanyin and Dashizhi seated together, a standing Mahavairocana statue, a standing Manjushuri statue, a standing Wenshu and Puxian statue, a Turning Dharma-wheel pagoda (轉法輪塔 Zhuanfalunta) of Zhao Zhifeng, the founder of Liu Benzun sect. These statues are considered to be produced by an overall master plan in the Middle or Late Period of the Southern Song. The Shiku is believed to be a site at which Zhao Zhifeng performed some Buddhist rites such as Water and Land Rituals (水陸法會 Shuilufahui). Income of the ritual was also a major part of the funding for establishing large-scale Baoding Shiku at Dazu District, Chongqing City.

• The Journal of Engineering Geology
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• v.32 no.3
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• pp.351-361
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• 2022

Numerical analysis performed to predict the behavior of Ipseok-dae columnar joints in Mudeungsan National Park to understand their stability and movement. The numerical analysis technique, 3DEC, is based on the discrete element method that can analysis discontinuities. The analysis used data for material properties derived from laboratory tests, which found that average density was 2.68 kN/m³, average normal stiffness was 3.15 GPa/m, average shear stiffness was 1.00 GPa/m, average cohesion was 0.51 MPa, and the average friction angle was 33°. The Ipseok-dae columnar joints were modeled on the basis of the field survey data for 15 joints located between the observation platform and the hiking trail. The numerical analysis assessed the behavior of each columnar joint by interpreting the displacement of the edges of its upper and lower surfaces. The greatest maximum displacement was found in columnar joint No. 6, and the greatest minimum displacement was found in joint No. 11. Analyzing the movements of five discontinuities in joint No. 11 indicated that the maximum displacement occurred at the 2nd level. The other levels were ordered 5th, 4th, 1st, and 3rd in terms of subsequent greatest displacements. Considering the total displacement in the 15 studied joints, the Ipseok-dae columnar joints are judged to be stable. However, considering the cultural and historical value of Mudeungsan National Park, it is regarded that the currents slope stability should be maintained by monitoring the individual rock blocks of the joints.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.681-689
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• 2023

Purpose: Muons are characterized by a strong penetrating ability and can travel through thousands of meters of rock, making them ideal to image large volumes and substances typically impenetrable to, for example, electrons and photons. The feasibility of 3D image reconstruction and material identification based on a cosmic ray muons tomography (MT) system with triangular bar plastic scintillator detectors has been verified in this paper. Our prototype shows potential application value and the authors wish to apply this prototype system to 3D imaging. In addition, an MT experiment with the same detector system is also in progress. Methods: A simulation based on GEANT4 was developed to study cosmic ray muons' physical processes and motion trails. The yield and transportation of optical photons scintillated in each triangular bar of the detector system were reproduced. An image reconstruction algorithm and correction method based on muon scattering, which differs from the conventional PoCA algorithm, has been developed based on simulation data and verified by experimental data. Results: According to the simulation result, the detector system's position resolution is below 1 ~ mm in simulation and 2 mm in the experiment. A relatively legible 3D image of lead bricks in size of 20 cm × 5 cm × 10 cm used our inversion algorithm can be presented below 1× 10⁴ effective events, which takes 16 h of acquisition time experimentally. Conclusion: The proposed method is a potential candidate to monitor the cosmic ray MT accurately. Monte Carlo simulations have been performed to discuss the application of the detector and the simulation results have indicated that the detector can be used in cosmic ray MT. The cosmic ray MT experiment is currently underway. Furthermore, the proposal also has the potential to scan the earth, buildings, and other structures of interest including for instance computerized imaging in an archaeological framework.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.229-238
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• 2023

Bentonite is a type of rock that has been used as a traditional mineral medicine. It has a variety of pharmacological activities, and is used in traditional Korean medicine to treat jaundice, diarrhea, and hemostasis. In modern medicine, it is used as a raw material and additive for medicines such as antacids, gastrointestinal protective agents, and laxatives. Bentonite produced in Korea was produced through diagenesis or hydrothermal alteration of tertiary volcanic debris distributed in the Pohang and Gyeongju areas. It is mainly used for industrial purposes such as papermaking, paint, civil engineering, casting, and animal feed. Recently, technology is being developed to use it in cosmetics and pharmaceuticals. In this study, the geochemical characteristics of bentonite were identified by analyzing the main components and trace elements of 40 and 21 types of bentonite produced in the Gampo Gyeongju and Yeonil Pohang area. Also it were classifed by formation envrionment of bentonite deposits in the Gampo and Yeonil. As a result of the study, bentonite from the reserch area may be cased by argillic alteraton that alkali elements are removed form basaltic rocks by hydrothermal fluids and AI-CCPI alteration indices wrere also indentified argillic alteraton. It was found that there is a correlation between the behavior characteristics of heavy metal elements (P b, Cr, As) and the hydrothermal alteration of bentonite in the reserch area.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.599-609
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• 2023

In the seismic retrofitting of harbor breakwaters in Korea, the recovery rate is often uncertain due to site conditions and site conditions, and problems continue to arise. Therefore, in this study, we analyzed the recovery rate and compressive strength of the improved material through drilling survey by grouting confirmation method after applying low-fluidity mortar injection method, and furthermore, we checked the elastic modulus by downhole test and tomography to confirm the reinforcement effect of soft ground after ground improvement. The experimental results showed that the average shear wave velocity of the ground increased from 229 m/s to 288 m/s in BH-1 and BH-3 boreholes to a depth of 28.0 m, and the average shear wave velocity of the ground to a depth of 30.0 m tended to increase from 224 m/s to 282 m/s in the downhole test. This is believed to be a result of the increased stiffness of the ground after reinforcement. The results of the tomographic survey showed that the Vs of the soft ground of the sample at Site 1 increased from 113 m/s to 214 m/s, and the Vs of the sample at Site 2 increased from 120 m/s to 224 m/s. This shows that the stiffness of the ground after seismic reinforcement is reinforced with hard soil, as the Vs value satisfies 180 m/s to 360 m/s in the classification of rock quality according to shear wave velocity.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.41-53
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• 2017

This study was performed to determine what the plant material were selected to reflect in the 2016 Korea Garden Show designer's garden. It was analyzed that plant material was used to display the theme of the garden and to create a specific space. Under the given theme of 'K-Garden, Shinhallyu Garden(new style garden culture) with the most Korean taste', the plants were used to highlight the theme in two types: 'representation' and 'expression'. There were two 'representation' gardens that imitate a particular space of Korean taste and four 'expression' gardens that showcase the designer's thoughts with abstract concepts and concrete objects. Three gardens included both types of garden. The way of revealing the subject with plants was used more for 'expression' than for 'representation'. There were eleven spaces for 'representation' of the Korean taste, a vegetable garden, faucet, pond, field, nature, a Hanok court garden, groves of bamboo, tile roof, stone wall, rock and backyard of a Hanok connected to the mountain. The planting material was used in two ways: reflecting only the ecological characteristics of the plant, and considering the ecological and visual characteristics together. Vegetation plantings reflecting the ecological characteristics were observed in all eleven spaces. Nine of the spaces reflected the growth environment of the plants, but the other two did not reflect the ecological characteristics of the plants, unlike the designer's intention. In the case of the four spaces that considered the ecological and visual characteristics together, color and size were considered visual characteristics. The plants in the seven spaces that included 'expression' as the theme were selected to reflect the visual characteristics in the order of color, shape, texture, and size, rather than reflecting ecological characteristics. A group planting method was applied. When the plants were used as materials for creating space, Norman(1989) analyzed three enclosure factors(overhead, vertical, ground plane). Only two deciduous trees were used in the overhead plane while five species of evergreen shrubs and thirty species of various deciduous plants were used in the vertical plane. There were forty-five species (nine trees and thirty-six herbaceous plants) forming the ground plane, and various herbaceous plants were utilized without duplication in each garden. The designer's garden of the Garden Show played a role in introducing new groundcover plants to the public. Three of the nine gardens did not include ornamental plants, and the use of decorative plants in other gardens was few compared to the number of plantings. In the Korea Garden Show designer's garden, most of the plants were being used with the intention of exposing the theme or architectural uses. In the 2016 Korea Garden Show designer's garden, many species of plants were used as materials for showcasing themes rather than for creating spaces. Also, the method of 'expression' was used more than the method of 'representation' in order to highlight the theme. This indicates that the planting materials reflect visual characteristics such as color, shape, texture, size rather than ecological characteristics.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.47-56
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• 2008

pH and Eh were measured at 25 points in the abandoned Dalcheon mine. And, major ion components $(Na^+,\;K^+,\;Ca^{2+},\;Mg^{2+},\;Cl^-,\;SO_4^{2-},\;CO_3^{2-},\;HCO_3^-)$ were analyzed through groundwater sampling at 41 points. pH and Eh were measured the highest concentration in serpentinite area. And, pH was between weak alkaline and intermediate values in study area. Groundwater in study area was dominated oxidation-reduction environment caused by reaction with carbonate rock. Because sulfur components contained in carbonate, serpentinite, arsenopyrite and pyrite was dissolved by groundwater, $SO_4^{2-}$ component was high in study area. And $Ca^{2+},\;Mg^{2+}$ of cations were high. Correlation coefficients of ion components in tailing dumps were 0.95 between $Ca^{2+}\;and\;SO_4^{2-}$, 0.86 between $Ca^{2+}\;and\;Mg^{2+}$, 0.85 between $Mg^{2+}\;and\;SO_4^{2-}$. Correlation coefficients of ion components in bedrock were 0.86 between $Mg^{2+}\;and\;SO_4^{2-}$, 0.68 between $Ca^{2+}\;and\;SO_4^{2-}$. Concentration range of $Ca^{2+}$ in tailing dumps was $6.85{\sim}323.58mg/L,\;and\;3.18{\sim}207.20mg/L$ in bedrock. Concentration range of $SO_4^{2-}$ in tailing dumps was $21.54{\sim}1673.17mg/L,\;and\;2.04{\sim}1024.64mg/L$ in bedrock. By the result of Piper diagram analysis with aquifer material, groundwater in tailing dumps was $Ca-SO_4$ type. Groundwater quality types with bedrock material were Mg-$SO_4$ and Mg-$HCO_3$ types in serpentinite area, Ca-$HCO_3$ type in carbonate area, Na-K and $CO_3+HCO_3$ types in hornfels, respectively. As a result of this study, groundwater in tailing dumps were dissolved $Ca^{2+},\;Mg^{2+}\;and\;SO_4^{2-}$ components with high concentration. Also, these ion components were transported into bedrock aquifer.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.267-275
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• 2018

The purposes of this study were to analyze the mineralogical characteristics of slaked lime used for wall repair of traditional buildings in Bagan, Myanmar and to evaluate the physical properties of lime plaster produced by the same method as Bagan region. In the X-ray diffraction and thermal analysis of the Myanmar slaked lime, portlandite ($Ca(OH)_2$) and brucite ($Mg(OH)_2$) were detected as main constituent minerals, and a carbonate rock mainly composed of dolomite ($CaMg(CO_3)_2$) minerals may be used as a raw material to make slaked lime. The field-emission scanning electron microscope analysis showed that the Myanmar slaked lime was composed of irregularly shaped crystals of $0.5{\mu}m$ or larger and a small amount of $0.1{\mu}m$ of plate - like crystals. The size and uniformity of crystals in Myanmar lime is different from that of Korea slaked lime. This may be attributed to the effect of the mineral composition and the lime hydration method of Myanmar, which produces slurry by immersing the burnt lime in excess water for a long period of time. The compressive strength of the lime plaster in Myanmar resulted in a mean value of $1.13N/mm^2$ for the specimens cured for 28 days. The strength of the specimens with Bale juice was $1.03N/mm^2$, respectively. The lime is an air setting material that exhibits strength through long carbonation process. Therefore, it is necessary to evaluate physical properties according to curing period through long-term curing over 28 days in the future.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.343-350
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• 2008

Purpose: The purpose of this study was to spectrophotometrically evaluate the shade difference between of maxillary and mandibular anterior teeth in the Korean by the standard of vita classical shade guide using $SpectroShade^{TM}$. Material and methods: In this study, the shades of healthy anterior teeth were examined and analyzed using the digital shade analysis of $SpectroShade^{TM}$. This study examined 80 individuals in their twenties, thirties, fourties, fifities ages and 40 males and 40 females, presenting 12 healthy, unrestored maxillary and mandibular anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The $SpectroShade^{TM}$ was used to acquire images of the 12 maxillary and mandibular anterior teeth. These images were analyzed using $SpectroShade^{TM}$ Software, and shade maps of each tooth were acquired. The shade difference of upper and lower, and gender differences and ages difference were investigated and analyzed with CIE $L^{*}a^{*}b^{*}$ color order system. One-Way ANOVA test was used to find out if there were significant differences between groups tested and Sheffe multiple comparison was used to identify where the differences were. Results: 1. Shade differences were significant (P < .05) between maxillary and mandibular central incisor, lateral incisor, canine. 2. No significant differences in shade distribution were seen between lateral incisors and central incisors. 3. Canine's shade difference were more significant than central incisor's and lateral incisors's. 4. No significant differences in shade distribution were seen between genders in maxillary and mandibulr central incisor, lateral incisor, canine. 5. No significant differences in shade distribution were seen in order of years in maxillary and mandibulr central incisor, lateral incisor, canine. Conclusions: The results of this study show that 1. Shade difference was founded in maxillary and mandibular anterior teeth and ${\Delta}E^{*}$ value was more than 2.0. 2. Canine's shade difference were more significant than central incisor's and lateral incisors's and between central incisors and lateral incisors shade differences were no significant. 3. No significant differences in shade distribution were seen between genders in maxillary and mandibular anterior teeth. 4. No significant differences in shade distribution were seen in order of years grade in maxillary and mandibular anterior teeth.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.409-419
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• 2008

Statement of problem: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. Purpose: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE $L^{*}a^{*}b^{*}$ system. Material and methods: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE $L^{*}a^{*}b^{*}$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation ${\Delta}E^{*}=[({\Delta}L^{*})2+({\Delta}a^{*})2+({\Delta}b^{*})2]1/2$. Results: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. Conclusions: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.