• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.285-288
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• 2008

Analytical studies are performed to evaluate the feasibility of column-type hybrid damper for seismic rehabilitation of existing buildings. For this purpose, at first, analytical model which can simulate the hysteretic behavior of column-type hybrid damper is proposed for use of commercially-available structural analysis program (MIDAS). Also seismic rehabilitation effects by column-type hybrid damper were evaluated by time history analysis for the existing building with vertical extension. From the analysis, it was found that base shear of typical building is reduced about 20% and story drift was reduced around 20% at critical story.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6906-6914
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• 2014

This study examined the remodeling characteristics of traditional urban housing for lease focusing on Hanok in the traditional urban housing neighborhood of Bukchon. Furthermore, the space syntax was used as the main analytic approach to objectively revealing the change in social properties of each spatial element because each room forms its status in the structural relation with many rooms and accommodates the special change in traditional housing and modern life. These findings revealed the following; spatial division between the landlord and tenant results in a hierarchical change in the yard and main hall and strengthens the privacy of the space of the landlord.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.199-208
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• 2016

This paper proposes renovation guidelines for impaired persons' facilities in Chungcheongnam-Do by reviewing the conditions of the facilities based on the standard and deinstitutionalization trends in foreign facilities. The facilities were located far from the downtown of cities. Therefore, education and adaptation programs are necessary for these people to return to society. Recombining the rooms for a living room-oriented unit considering the structure system of the facilities allows good adaptation to home-based living conditions for impaired people. The area per person will be increases by renovations to a living room-oriented unit that makes upgrades to near foreign standards, such as The USA and The UK.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1149-1156
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• 2014

In order to reduce flood damages, there should demand an appropriate design such as enlarging a bank, dredging a river bottom, building a hydraulic structure and so on. The installation locations about the Watergate are listed of the seven provisions in the river design standard, but it is not detailed. In order to compute proper place considering landuse and basin characteristics of inlands, internal inundation modeling that should be performed is regarded with quantitative evaluation. Anyway, that is very complex and taking a long time because that has to consider hydraulic and hydrologic characteristics. In the current study, therefore, the simple and convenient method for internal inundation modeling was proposed to overview the Watergate location.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.317-338
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• 2022

Physicochemical characteristics and evaluation were studied by subdividing the concretes, bricks and earth pipes on the site of the Japanese Ministry of General Affairs in Joseon Dynasty, known as modern architecture, into three periods. Concretes showed similar specific gravity and absorption ratio, and large amounts of aggregates, quartz, feldspar, calcite and portlandite were detected. Porosity of the 1907 bricks were higher than those of 1910 and 1950 bricks. All earthen pipe is similar, but the earlier one was found to be more dense. Bricks and earthen pipes are dark red to brown in color within many cracks and pores, but the matrix of the earthen pipe is relatively homogeneous. Quartz, feldspar and hematite are detected in bricks, and mullite is confirmed with quartz and feldspar in earthen pipes, so it is interpreted that the materials have a firing temperature about 1,000 to 1,100℃. Concretes showed similar CaO content, but brick and earthen pipe had low SiO₂ and high Al₂O₃ in the 1907 specimen. However, the materials have high genetic homogeneity based on similar geochemical behaviors. Ultrasonic velocity and rebound hardness of the concrete foundation differed due to the residual state, but indicated relatively weak physical properties. Converting the unconfined compressive strength, the 1st extended area had the highest mean values of 45.30 and 46.33 kgf/cm², and the 2nd extended area showed the lowest mean values (20.05 and 24.76 kgf/cm²). In particular, the low CaO content and absorption ratio, the higher ultrasonic velocity and rebound hardness. It seems that the concrete used in the constructions of the Japanese Ministry of General Affairs in Joseon Dynasty had similar mixing characteristics and relatively constant specifications for each year. It is interpreted that the bricks and earthen pipes were through a similar manufacturing process using almost the same raw materials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.207-210
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• 2000

We investigated the structure of floral organs and possibility of seed-set to breed a variety in ginger Zingiber officinale Rosc. Floral bud was formed from collected domestic Seosan var, and foregin Thailand var, the number of florets per bud were 8 and 10 in Seosan and Thailand var, respectively, Flowering time ranged from 18 to 25 August irregularly at 4-5 pm. The flower has the long styled with fiber hairs on top of stigma and connected-two anthers. Pollens were mixed of circular and ellips shape and its extine was two layer structure. Callus formation from anther explants was effective with compact and embryogenic on N$_{6}$ medium supplemented 2 mg/l of NAA(NCM). Plant regeneration was on the MS medium with BA of 1-2 mg/l from 40 days old callus after transferred callus medium.m.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.654-658
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• 2006

To solve some problems that reveals in the exiting stickiness problem of the housetop, the housetop finishing impact layer can be displaced by the existing concrete block. By doing in this way, this need is rising that the excess cost should be reduced and the materials should be recycled in repairing. According to the above, this study is going to suggest the basic data on building and using of the dry process method by estimating and analyzing a overall determinate quantity through the experiment on the insulation performance among the capacity items on the outside insulation waterproof dry process suggested. In addition, choosing the building method according to the use, the peculiar property and the importance of the building can be possible by analyzing the defect causes happening in the rooftop insulation and waterproof, suggesting the better method and classifying the most proper choosing methods for the need of the building according to the importance of the main factors.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.69-80
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• 2022

The proportion of buildings over 30 years old in Korea has increased, from 29.0% in 2005 to 37.8% in 2019. These old buildings were built during a time in which there was a lack of building-related safety standards in areas such as fire safety performance. Worse, during their years of use, many such old buildings have had illegal changes and extensions made, making them more vulnerable in terms of safety. Fire safety investigations are being conducted to prevent large-scale disasters in multi-use buildings, but no investigation has been conducted at the regional district level, where small-scale old buildings are concentrated. Therefore, to identify fire risk factors in the old building district where old buildings are concentrated, the composition characteristics of the buildings were first analyzed. To examine the spatial characteristics of old building districts in order to derive fire risk factors, the results of this analysis based on the structure, use, roof type, and year of approval for use are as follows. It was found through our analysis that as of the date of approval for the use of the building, the main structure of the building has the greatest impact.

• Journal of Conservation Science
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• v.32 no.3
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• pp.299-312
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• 2016

The Daehan Uiwon (Historic Site No. 248) in which the predecessor of Seoul National University Hospital is a crucial medical institution that built in the Korean Empire period. One of them, East 1 Affiliated Ward that attached to Daehan Uiwon was built with concrete foundation in 1908 and extended two times in 1935 and 1954. As a result of material scientific analysis for concrete foundation, all of the foundation is composed of mortar and stone aggregates, however, the mixing proportions between the aggregate and the mortar were confirmed to be different with construction periods. To determine the mixing proportion, and physical properties by ultrasonic velocity and rebound hardness, the concrete foundations by construction period were obtained. In result, 1954's mixing proportion of concrete between mortar and stone aggregate indicated the highest ratio of aggregates with 1 : 35, mean value of ultrasonic velocity and unconfined compressive strength were calculated with 450 m/s and 18.92 MPa in 1954's constructions that is the lowest values compared with other times. As a result, the difference characteristics of physical properties by construction periods are possible interpreted with porosities and mixing ratios of stone aggregates.