• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.606-612
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• 2019

The main causes of subsidence and sinkholes in the lower part of urban roads are sewage line foundation and inadequate compaction of backfill material. This leads to many problems, such as the breakage of joints in sewer pipes, poor connection, pipe breakage, and cracks. To solve this problem, the support factor related to the sewer foundation and the safety factor according to the excavation depth were evaluated. For the foundation of rigidity tolerance, crushed stone foundation, and abandoned concrete foundation, a recently newly developed site assembly-type lightweight plastic foundation were used. Backfill materials were applied on site (sandy soil and clayey soil) and fluid backfill was recycled onsite. To evaluate the depth of excavation and the safety factor of each sewer pipe foundation, the design load considering the load factor and the support factor was evaluated. The support coefficients were 0.377 for a crushed stone foundation, 0.243 and 0.220 for an abandoned concrete foundation ($180^{\circ}$ and $120^{\circ}$), and 0.231 for a lightweight plastic foundation and fluid backfill. Overall, the safety factor was low when using the crushed stone foundation, and the safety rate was the highest when the foreclosed concrete foundation ($180^{\circ}$) was used. In addition, when the combination of lightweight plastic and fluid backfill materials was used, the safety factor was higher than that of abandoned concrete foundation ($120^{\circ}$), which means that the newly developed lightweight plastic foundation can be used as another alternative base of a steel pipe.

• (The)Study of the Eastern Classic
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• no.32
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• pp.391-424
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• 2008

A Buddhist relic deposit was discovered from the three storied stone pagoda which was called as Seokgatap of Bulguksa temple in Gyeongju in 1966. In this relic deposit, several clumped papers written in ink which were found from the pagoda. These manuscripts are one of the most valuable materials for understanding Korean Buddhism and Buddhist Art History. In this paper, I examined several terms for pagoda subsidiaries found in these manuscripts, which have not been known to us up to recently. In addition, I compared these terms to the real pagodas or pagoda images in Korea. The manuscripts from Seokgatap pagdoa were composed of three different kinds of records; (1) "Record for the Repair of Mugujeonggwangtap Pagoda (無垢淨光塔重修記, 1024)"; (2)"Record for the Reconstruction of West Pagoda (西石塔重修形止記, 1038); (3)"Lists of Donors for the Reconstruction of the Pagoda in Bulguksa temple (佛國寺塔重修布施名公衆僧小名記, 1038). The terminology describing pagoda was appeared in the first and the second records. In the "Record for the Repair of Mugujeonggwangtap Pagoda", there are more than ten terms, which are presumed to be the words describing some upper decorative parts of a stone pagoda. However, in the "Record for the Reconstruction of West Pagoda", there are fifteen terms which would describe the body and base parts of the Seokgatap pagoda. These new terms for pagoda subsidiaries appeared in the manuscripts of Seokgatap Pagoda are very significant materials in understanding Korean Buddhist Art, because they show the practical terms which were used in the eleventh century Buddhism of Korea, but never known to the modern academic world. The manuscripts of Seokgatap Pagoda have not been deciphered perfectly yet, so they have to be examined with more precise as well as with wider view of Buddist and Art History.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.277-284
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• 1998

The purpose of this study was to evaluate the propriety of making use of the light-cured resin base in indirect bracket bonding technique by study of shear bond strength and failure patterns according to the material of resin base. Metal brackets were bonded to the stone models of specimens involving bovine lower incisor with chemical-cured(Excel), light-cured(Light-Bond) and thermal-cured(Therma-Cure) resin. They were transferred to the specimens and bonded using sealant. The shear bond strength was tested on Instron. After bracket removal, the bracket base was examined and assessed with the adhesive remnant index(ARI). The results were as follows : 1. No significant differences in shear bond strength were found among the three groups (P>0.05). 2. No significant differences in ARI score were found among the three groups (P>0.05). The above results suggest that light-cured resin base in addition to chemical-cured and thermal-cured resin bases is useful in the indirect bonding technique.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.99-107
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• 2015

A natural hybrid of a probable intergeneric mating between the striped shiner Pungtungia herzi and the stone morocco Pseudorasbora parva (Cypriniformes: Cyprinidae) was captured in the Geumho River, a tributary of the Nakdong River basin in Korea. Morphological characters and DNA sequences were analyzed to verify its hybrid state and identify the parentage of its parent species. The hybrid exhibited a phenotypic intermediacy between the two parent species in the number of vertebrae and the mouth shape. Out of 1,488 base pair (bp) positions of the nuclear recombination activating gene 1 gene (rag1), which has a biparental mode of inheritance, 41-bp substitutions were detected between the two parent species, whereas an electropherogram of the hybrid displayed polymorphic double peaks at all of the base positions, along with one additional one, strongly indicating its hybrid state. Meanwhile, sequence comparison of the mitochondrial cytochrome b gene (mt-cyb) (1,140 bp), which has a maternal mode of inheritance, showed only 5-22-bp differences (97.6-99.5% identities) between the hybrid and Pu. herzi, but as many as 158-168-bp differences (85.2-86.1% identities) between the hybrid and Ps. parva, clearly indicating Pu. herzi as the maternal species. Thus, combined analyses of independent data sets (i.e., morphology and nuclear and mitochondrial DNA sequences) offered convincing evidence for the hybrid state of a naturally occurring hybrid resulting from intergeneric mating between a female Pu. herzi and a male Ps. parva.

• Journal of Technologic Dentistry
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• v.34 no.4
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• pp.353-359
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• 2012

Purpose: The aim of this study measured and compared the marginal and internal fit of metal cores with two base metal alloy (Ni-Cr alloy(non-beryllium), Co-Cr alloy). Methods: Maxillary right first molar abutment fabricated by titanium was prepared for this study. Impressions(10ea) were made from titanium model, and study models were poured with improved dental stone. Wax cores of twenty were prepared for burn-out and casting. Ten wax cores cast Ni-Cr alloy(non-Be), and finally ten cast Co-Cr alloy. Marginal and internal fit of cores was evaluated using silicone replica technique and digital microscope(x160). The data were statistically analyzed with the independent samples t-test (${\alpha}$ <.05). Results: Mean(standard deviation, SD) marginal and internal fit total size of Ni-Cr alloy(non-Be) group was $73.3(14.4){\mu}m$ and of Co-Cr alloy group $65.6(17.4){\mu}m$. The marginal and internal fit total size of Ni-Cr alloy group(non-Be) was statistically significantly greater than that of Co-Cr alloy group (P=.004). Conclusion: Co-Cr alloy cores in this study had a better marginal fit than Ni-Cr alloy(non-Be) cores.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.1-8
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• 2010

Construction of road closed to mountains is inevitable in Korea because the mountainous region in Korea is more than 70% in area. Recently, due to global warming, typhoons or heavy rainfalls frequently occur, and accordingly, mountain roads are seriously damaged by landslides, debris flows, and uplift pressure below pavement. in this study, damage on pavement by uplift pressure was investigated. Various influencing factors such as slope angle, reinforcement of slope surface, thickness of soil cover underlain by rock, and types of drainage system were considered to evaluate uplift pressure acting on the bottom of pavement. Raising of water table up to the surface of slope may depend on the duration and intensity of rainfall. It shows that the installation of subdrain can reduce the uplift water pressure. Therefore, It is concluded that the use of subdrain system is effective to decrease uplift pressure and cement treated base is more endurable than typical crushed-stone base.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.203-214
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• 2024

Ports often suffer pavement damage due to soft ground and heavy equipment operations, leading to issues such as differential settlement and cracks. In this study, we developed port concrete blocks and applied them to a port in two configurations to figure out settlement characteristics. Falling weight deflectometer (FWD) tests on asphalt pavement and block pavements were conducted to figure out deflection and bearing capacity. The block pavement with the cement treated base showed improved bearing capacity with the port operation since lower settlements were detected than asphalt pavement. In the cement treated base, the relative deflection ratio to asphalt concrete pavement was less than 1, indicating enhanced bearing capacity. LiDAR measurements identified multiple settlements in the crushed-stone base due to surface loads after construction. Both relative deflection ratio and LiDAR measurements suggested that block pavement can be widely applied to various port sites with its applicability and bearing capacity of cement-treated base.

• Journal of architectural history
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• v.18 no.6
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• pp.47-64
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• 2009

This research was to analyze the inland signal-fire which is the main facility of military protective duty for safety of land in chosun dynasty. The results of this research were described separately as follows. 1. Five types of site plan of signal-fire were observed, which is circle, oval, rectangular, indeterminate form. The majorities were oval type. 2. Plan configuration of brazier which is separated with circle, rectangular type roughly was constructed with circle type generally. The height of brazier was about 3~4.5m. The diameter of brazier was 1.5~2.5m. Building base that protect ground moisture and infilteration of rainfall was found in 5 inland singal-fire, the height of it was about 0.3m~2.5m. 3. The heigh to protective wall remained until present was about 1m, the depth was about average 1.2m. 4. Entrance was mainly stairs or open type and average width was 1.0~1.2m. However the depth was almost observed as 1m, originally, it was estimated it has more depth. 5. The storage of inland signal-fire has rectangular dimension, several types of $1.8{\times}1.2m{\sim}5.7{\times}4.4m$, square(間) of $1{\times}1{\sim}2{\times}1$. The building material was stone and located below or near the brazier.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.371-373
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• 2003

In experiments on sea water, it took longer to reach almost steady state and the foam heights were increased as increasing initial protein concentration. The foam height was increased with the decrease of the pore size. G3, G4, and air stone were similar. It was increased with the increase in the superficial air velocity (SAV) and it was efficient when the SAV is $0.7{\sim}0.8\;cm/sec$. The optimum pH condition is weak acid and weak base region. The influence of salts, $NaHCO_3$, was not that significant due to NaCl in the sea water.

• 한국문화재보존과학회:학술대회논문집
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• 2001.11a
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• pp.15-18
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• 2001

The sarira reliquary excavated as a lot of fragments were restored by conservation treatment by us. The sarira reliquary was made using fine techniques such as chasing work and engraving work, etc. The analysis of base metals showed that different materials had been used on decorative parts in consideration of the casting and forging technique. Gold granules $(97wt\%\;Au)$ of the small bell were adhered by using a soldering material $(85wt\%\;Au,\;10wt\%\;Ag)$. The lead isotope analysis of lead glass $(74wt\%\;PbO)$ revealed that it agreed with the lead mine in the middle of south area in Korea.