• Journal of The Geomorphological Association of Korea
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• v.27 no.1
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• pp.103-115
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• 2020

This study has analyzed and revised the geomorphological terms in the Reference Guide for Geography Textbook Compilation issued by the Ministry of Education in 2017. The current geography glossary is composed of 1,150 terms of which 24.4 percent are geomorphological one. They also amount to 52.2 percent of the terms registered in the physical geography glossary. The number of terms in coastal landforms is the maximum of fifty-eight, while the one in weathering landforms is the minimum of six. This suggests a large difference in the number of terms among landform types originating from varying geomorphic processes. A lot of ordinary words are included in the geomorphology glossary. Since they have been already registered in the Korean Standards Dictionary which is another reference guide for textbook compilation, it is appropriate to delete them out of the geomorphological terms. The geomorphology glossary also contains difficult terms written in Chinese characters, inappropriate terms and even incorrect terms which are likely to lead to misconception on landforms. The revised glossary consists of 284 geomorphological terms in which 101 terms are newly added after taking all the problems into consideration.

• Journal of Korean Association for Spatial Structures
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• v.24 no.2
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• pp.53-63
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• 2024

The cultural heritage of fortresses is often exposed to external elements, leading to significant damage from stone weathering and natural disasters. However, due to the nature of cultural heritage, dismantling and restoration are often impractical. Therefore, the stability of fortress cultural heritage was evaluated through non-destructive testing. The durability of masonry cultural heritages is greatly influenced by the physical characteristics of the back-fille material. Dynamic characteristics were assessed, and endoscopy was used to inspect internal fillings. Additionally, a finite element analysis model was developed considering the surrounding ground through elastic wave exploration. The analysis showed that the loss of internal fillings in the target cultural heritage site could lead to further deformation in the future, emphasizing the need for careful observation.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.1
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• pp.21-27
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• 2012

Decomposed granite soils are in a wide range of conditions depending on the degrees of weathering. This paper is intended to examine laboratory tests such as consolidation tests and conventional triaxial compression tests conducted in order to find out the mechanical properties of Cheongju granite soil. Along with the foregoing, the results of basic physical tests conducted in order to grasp the physical properties of Cheongju granite soil were described and based on the results, methods to calculate the mechanical parameters of numerical approaches using Lade's double surface work-hardening constitutive model were examined. Finally, it is intended to explain the stress properties of Cheongju granite soil used as a geotechnical material based on its shear behavior and critical state concept using the results of isotropic consolidation tests and triaxial compression tests. As a conclusion, it can be seen that in the relationship between confining stress and maximum deviator stress, the slope is maintained at a constant value of 2.95. In the drained CTC test, maximum deviator stress generally existed in a range of axial strain of 6~8% and larger dilatancy phenomena appeared when confining stress was smaller. Finally, based on the results of the CTC tests on Cheongju granite soil, although axial strain, deviator stress and pore water pressure showed mechanical properties similar to those of overconsolidated soil, Cheongju granite soil showed behavior similar to that of normally consolidated soil in terms of volumetric strain.

• Polymer(Korea)
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• v.24 no.1
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• pp.72-81
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• 2000

Benzoic acid polyester/lactone polyol were synthesized by polycaprolactone 0201 as diol, trimethylolpropane as triol, adipic acid as dibasic acid, and benzoic acid as monobasic acid. Polyisocyanate prepolymer Desmodur N-100 of HDI-biuret type was used in this study. Two-component polyurethane coatings were prepared by blending benzoic acid polyester/polycaprolactone, polyisocyanate, wetting/dispersing agent, white pigment, and flowing agent. Various properties were examined on the film coated with the prepared polyurethane. They showed excellent physical properties such as abrasion resistance, accelerated weathering resistance, and yellowness index. They also showed good physical properties such as flexibility, impact resistance, 60$^{\circ}$ specular gloss, cross hatch adhesion, hydrocarbon resistance, and lightness index difference. Hardness of coating showed a little poor character. The introduction of polycaprolactone 0201 as diol in the polyurethane coatings improved the hydrocarbon resistance, impact resistance, and flexibility of coatings. According to the drying and curing behavior with the contents of benzoic acid, they seem to have reasonable coating properties such as drying time of 2 to 4 hours and pot-life time of 20 to 37 hours.

• Journal of the Korean Applied Science and Technology
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• v.22 no.4
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• pp.362-370
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• 2005

Copolymers (HSA-98-20, HSA-98-0, HSA-98+20) which are acrylic resin containing 80% solid content were synthesized by the reaction of monomers, including methyl methacrylate, n-butyl acrylate, and 2-hydroxyethyl acrylate with a functional monomer, such as acetoacetoxyethyl methacrylate (AAEM), which may improve in cross-linking density and physical properties of films. The physical properties of prepared acrylic resins, containing AAEM, are as follows : viscosity, $1420{\sim}5760cps$ ; number average molecular weight, $2080{\sim}2300$ ; polydispersity index, $2.07{\sim}2.19$ ; conversions, $88{\sim}93%$, respectively. To prepare acryl resins, four kinds of initiators including ${\alpha},{\alpha}'-azobisisobutyronitirile$ (AIBN), di-tert-butyl peroxide (DTBP), t-amylperoxy-2-ethyl hexanoate (APEH), benzoyl peroxide (BPO) were used. The viscosity of the acrylic resins prepared with these initiators was increased in the order of DTBP>APEH>AIBN>BPO. APEH was proved as a suitable initiator in this study. Shear rates of acrylic resins were constant in respect to viscosity. From these results, it would appear that the resins have Newtonian flow characteristics and good workability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2026-2031
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• 2009

Because the stone cultural properties located outdoors, they have been altered and deteriorated in external appearance due to environmental factors. Damage to stone cultural properties is accelerated particularly due to recent industrial development and environmental pollution. When fresh granite was dipped into the seawater, the mineral compositions(Ca, K) of the granite surface were lower then those of the fresh granite and density of the weathered granite was steadily decreased from $2.600 g/cm^3$ to $2.580-2.582 g/cm^3$. Also, absorption capacity of the weathered granite was steadily increased from 0.392% to $0.526{\sim}0.616%$. In the case of $TiO_2$ was coated to the granite, the change of density and absorption ratio of $TiO_2$ coated granite were decreased. Therefore, the $TiO_2$ coating considered to be a viable method to assist in the conservation of stone cultural properties from environmental contaminants.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.137-150
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• 2021

The rock-carved standing Buddha triad in Seoak-dong is a large stone Buddha statue of the Unified Silla era (AD 676 to 935) in ancient Korea, built near the top of the southeastern side of mountain Seondosan in Gyeongju, is characterized by its locational importance, the powerful Amitabha and the gentle sculptural technique of the Bodhisattva. In particular, Amitabha Buddha in andesite rock slope with biotite granite pedestal and two Bodhisattva parallel made by alkali granites seems to express the dignity through the color and texture of the stones. In the Amitabha Buddha, deterioration characteristics are accelerating due to the combination of various joint systems, instability of the slopes and relaxation by the root pressure of plants occurring at the top. In addition, physical properties have deteriorated owing to the increase of discontinuous surfaces as joints, cracks and scalings, and the coverage of algae and lichen is also high. Therefore, deterioration degree in Buddha triad is accelerated due to the physical weathering characteristics from natural rock mass and various biological invasion.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.183-192
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• 2008

Stone cultural heritages in Korea are mostly situated out door without any notable protection thus there are severe damage from chemical and biological weathering. This in turn, causes deformation and structural damage. To counter act this problem and to increase durability, various kinds of conservation materials are used in the conservation and restoration treatment. However, there are not many practical and technological experiment done on this subject. This paper attempts quantitative evaluation of effectiveness of ethylsilicate based resin for Namsan granite in Gyeongju. When two different materials with different ethylsilicate concentration were compared, the result indicated decrease of absorption and porosity with increase of ultrasonic velocities, uniaxial compressive strength, elastic constant, tensile strength and Poisson's ratio. In addition, comparison of physical characteristic of the conservation material resulted favorably toward ones with higher concentration of ethylsilicate. This is due to the ethylsilicates characteristic to fill the internal pores of stone. There is discolouration of stone surface after treatment with conservation material. This was more prominent with the product of higher ethylsilicate concentration.

• Journal of Conservation Science
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• v.16 s.16
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• pp.39-51
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• 2004

The standing Buddha named Taehwa 4 yew in the Jincheon were sculptured with rock cliff of the dark grey shale. Front of the Buddha statue shows $N40^{\circ}W$ strike with nearly vertical dip toward the back side. Rock blocks of the Buddha statue well developed with bedding and laminations whereas rock surface distributed into the various irregular discontinuities. Sculptured lines of the Buddha were uncertain because of degradation and exfoliations on the rock surface. The surface near the Buddha statue is highly contaminated with lichen and mosses, and accelerate physical and biological weathering owing to the roots of weed and bush along the fracture systems. For the conservational treatment, we treated with primary wet cleaning by air gun and secondary cleaning treatment using distilled water. Separated rock surface and fractured parts fasten and/or fill up the boundaries of the rock blocks using epoxy resin for conservation of rock properties. Some brittle surface was treatment with water repellent consolidant of ethyl silicates, and heterogeneous surface carried out color matching by acrylic pigments. Upper part of the Buddha statue dig out small ditch for rain water drainage, and near surface of the Buddha statue treat removal works for lichen, weeds and bush. The duration capacity of the Buddha constituting rocks are degraded by various weathering factors, therefore we suggest that this Buddha statue have need to do long term monitoring and synthetic conservation researches.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.597-603
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• 2010

The amount of pollutants from stationary sources of businesses classified into 1-3 type in Gyeongju was found to be 0.70 ton/yr for PM-10, 13.95 ton/yr for $SO_2$, and 37.12 ton/yr for NOx ; with respect to area sources, 1.02 ton/yr for PM-10, 13.44 ton/yr for $SO_2$, and 21.10 ton/yr for NOx ; and with respect to mobile sources 963.91 ton/yr for PM-10, 1415.02 ton/yr for $SO_2$, and 5612.70 ton/yr for NOx. This study surveyed the concentration distribution of PM-10, $SO_2$, and NO2 in the air in around Gyeongju and Pohang, and found that high concentration was mainly distributed around Pohang Steel Industrial Complex and the around of mobile sources. In Gyeongju area, $SO_2$ was predicted to increase from 0.002 ppm in 2006 to 0.005 ppm in 2015, and that of $NO_2$ was predicted to increase from 0.004 ppm to 0.010 ppm during the same period. At this point, practicing guidelines to reduce air pollutants and management plan for environmental pollutants should be devised, and also practicing and management programs to protect the stone cultural properties from environmental pollutants and other chemical, physical, and biological factors should be actively introduced.