• Journal of the Korean Geophysical Society
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• v.4 no.2
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• pp.103-111
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• 2001

Geophysical survey was carried out to derive some information on the existence of near-surface anomalous body at Reung-Chi area in Kongju. Resistivity, seismic, magnetic and gravity method were applied. Geophysical survey that was applied was the electrical resistivity survey, seismic survey, magnetic survey, gravity survey. These surveys are analyzed to provide data of high resolution. As a result of analysis of resistivity survey, anomalies showing high resistivity anomaly than around appeared, and the one showing M-shape out of those explains the possibility that underground common or other underground structure or geographical anomalous zone could exist in the underground. As a result of analysis of seismic survey, it is clear that the low velocity layer is spread as far as the bottom of the underground. It is possible to presume that it is a phenomenon appearing while going through the underground space where it is lying in the underground. Area that shows unusual situation in interpretation of data on seismic waves are included into the area that once showed resistivity anomaly, the results of both seismic surveys come in accord. As a result of magnetic survey, a circle-shape of twin magnetic fields in the area where abnormalities are shown between electrical resistivity survey and seismic survey is appeared. Given the area of gravity survey, abnormalities whose density is different from the one around the bottom of the underground. As a result of analogizing the data of underground of the subsurface based on analysis of data from each survey, it was interpreted that anomalous zone exists commonly in the research areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.197-205
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• 2020

Compared to aerial photogrammetry, UAV photogrammetry has advantages in acquiring and utilizing high-resolution images more quickly. The production of 3D models using UAV photogrammetry has become an important issue at a time when the applications of 3D spatial information are proliferating. Therefore, this study assessed the feasibility of utilizing 3D models produced by UAV photogrammetry through quantitative and qualitative analyses. The qualitative analysis was performed in accordance with the LODs (Level of Details) specified in the 3D Land Spatial Information Construction Regulation. The results showed that the features on planes have a high LoD while features with elevation differences have a low LoD due to the occlusion area and parallax. Quantitative analysis was performed using the 3D coordinates obtained from the CPs (Checkpoints) and edges of nearby structures. The mean errors for residuals at CPs were 0.042 m to 0.059 m in the horizontal and 0.050 m to 0.161 m in the vertical coordinates while the mean errors in the structure's edges were 0.068 m and 0.071 m in horizontal and vertical coordinates, respectively. Therefore, this study confirmed the potential of 3D models from UAV photogrammetry for analyzing the digital twin and slope as well as BIM (Building Information Modeling).

• Journal of the Korean Geophysical Society
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• v.6 no.1
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• pp.39-46
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• 2003

Twin stone pagodas of the ruins of Kamunsa temple at Kyongju city, Kyungsangbukdo were believed to be built in 682 during the Unified Shilla Kingdom. The 13.4-m-high granodiolite pagodas with the base of 6.78 m x 4.4 m are the largest three-story stone pagoda in Korea. The western pagoda which was re-organized in 1959 is observed to be on the process of severe weathering. Also, some stone contacts are represented by the shape of sharp chevron, which is probably caused by the uneven loading due to the structural unbalance. For the structure-safety diagnosis of the western pagoda, it is necessary to understand its site characteristics and surrounding subsurface environment. Combined geophysical survey such as seismic and resistivity methods was carried out around the western pagoda. The range of 55∼350 Ωm is shown around the pagoda from the electrical resistivity mapping by the Wenner method. The higher resistivities occur the southwestern area, while the lower (<100 Ωm) values indicating the weaker subsurface appear to be on the northeastern area. This result coincides with the measurement of a leaning angle of the pagoda. Along 6 seismic lines, about 3-m-thick uppermost section around the pagoda shows the P-wave velocity of 200∼700 m/s from the refraction survey. Based on the integrated geophysical survey, the foundation of the pagoda is estimated to be in the form of 11-m-side square down to the depth of 3 m.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.167-174
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• 2009

Recently, design technology of has been required such as catamaran yacht with high-speed according to expand a marine leisure industry. The domestic technical development for design and production of yacht is not actively than Canada, USA, Japan etc. However, with further development of yacht design & technology, it is need to develop a key technology related to increase the value of catamaran yacht. In the present paper, new guideline is suggest for catamaran yacht as like kinds of marine leisure ship in order for fundamental structure design and structural analysis for twin-hulled ship yacht and techniques for structural analysis as sea leisure ship in this research. The class of society has not been proposed formally about regulation and methodology for estimation of strength of small hight-speed craft with satisfying two conditions as noted; length less than 50meters, ratio of length to breadth less than 12. In the present study, we were adopted DNV (Yachts, Design Principles, Design Loads, Hull Structural Design) Rule and KR (FRP rule application guide) for scantling of structural members. Furthermore, ABS rule is used for structural calculation about application of loading conditions for catamaran yacht. This study can be available feedback role to manufacture of 38ft diffusion style for catamaran yacht. It is expected that this study will be a good reference in order to design of catamaran yacht with high-speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.21-26
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• 2018

Thermoplastic starch (TPS) was prepared by mixing starch with glycerol as a plasticizer. The glycerol content ranged from 20 to 35 wt. % and TPS was prepared in a twin screw extruder. The shear viscosity, thermal and mechanical properties of the TPS were investigated. The viscosity of TPS exhibited typical shear thinning behavior: decreasing viscosity with increasing shear rate. The power index, n, increased with increasing glycerol content. This is because as the content of glycerol, a Newtonian fluid, increases, the viscosity behavior of the TPS becomes closer to that of a Newtonian fluid. The thermal behavior of TPS showed that starch and glycerol are miscible. In addition, when TPS was aged for more than one day at room temperature, TPS showed a partially miscible phase structure. The moisture absorbed into the TPS was assumed to change the phase behavior. The mechanical properties of TPS were found to be strongly dependent on the content of the plasticizer. Both the toughness and stiffness increased with increasing plasticizer content. DSC showed that this unusual result was due to the combined effect of humidity and the high amylose content in starch.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.110-119
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• 2015

Bronzes, Earthenwares and various artifacts were excavated from Pungnap earthen fortress in the early Baekje age in Korea. This study was performed in order to identify the manufacture technology of bronze artefacts and provenance of lead in bronzes. Microstructure and chemical composition results show that 3 of them are Cu-Sn-Pb alloys in which an intentional lead addition was carried out and one is tin bronze showing straight twin structure within crystal grains. Also $CuFeS_2$ or $Cu_5FeS_4$ was used as raw materials through the detection of S and Fe as trace elements. The lead isotope results could be matched with one of the zones of southern Korea and China on the East Asian map. This results shows that data were plotted either in zone 2 or zone 3 of the South Korean galena map. However, one of bronze artifacts was matched with the zone of Northern China.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.4
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• pp.14-22
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• 2012

The position, size and landscape of the former Donam SeoWon as well as the physical organization of the old site, are studied to extract data for the enhancement of the authenticity of Donam SeoWon since its registration as a world heritage site. The results are as follows. The 'Donam(豚巖)' encaved rock, the tombstone of teacher Sagye(沙溪), Kimjipsadang(金集祠堂), the head of the Gwangsan Kim family, the Sagye stream in front of them, and the Gyeryong and Daedun mountains in the distance are united in the former Donam SeoWon as landscape elements that clearly show the characteristics of the former site, which was called 'Donam-Wollim(豚巖園林).' Moreover Yangseongdangsipyoung(養性堂十詠), adds the garden elements of a medical herb field, twins pond, a bamboo forest, a school, and a peach field. On this site, one can also engage in activities that are related to the land and are closely related to Neo-Confucianism such as fish watching, conferencing, visit in seclusion(訪隱), looking for monks, and overseeing farming. The former site facing east is assumed to have Sau(祠宇) - Eungdodang(凝道堂) - Ipdeokmum(入德門) - Sanangru(山仰樓: estimated). Jeonsacheong seems to have been located to the left of the Sau area, Yangseongdang, which contained upper and lower twin lotus ponds, on the right and was surrounded by various plants. As it has been used as a lecture hall for the past 250 years, the former Donam SeoWon, located 1.8km away from the current area, must be preserved, and the landscape should be formed to establish the authenticity of Donam SeoWon.