• Journal of Conservation Science
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• v.18 s.18
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• pp.5-18
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• 2006

Dujeong-dong site of Cheonan is known as the site of Baekje period in the first half of the fourth century. This study investigated the visible properties and the chemical composition of the 18 pieces of the glass found in the site, and considered scientific properties and periodic interrelationship of the glass on the basis of the analysis result. The observation of the visible properties and microstructure of ancient glass was performed with both an electron microscope and an optical microscope, and the chemical composition was conducted by way of both quantitative and qualitative analysis using Scanning Electron Microscope(SEM) with Energy Dispersive Spectrometer(EDS). In the analysis result, various chemical composition systems are identified in the glass beads of Dujeong-dong site, such as lead-barium, soda and potash glass, and also different shapes were found such as gold foil glass beads, tubular beads, and round beads. It is estimated that the classification of glass by means of its chemical composition was also closely related to the color of glass.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.41-56
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• 2020

For the rapid and accurate warning, the system requires not only the sufficient number of seismometers but also the appropriate detection technique of sensor data. Instead of installing new seismometers, on-board accelerometers of the train could be utilized as alternatives. However, the data from on-board accelerometers includes train vibrations and the response of embankment site by earthquake, which are different from earthquakes measured from the seismometer. This study suggests signal analysis technique to detect earthquake from the on-board accelerometer data. The virtual on-board accelerometer data including the response of embankment site, obtained from site response analysis method, has been constructed. The constructed data has been analyzed using short time Fourier transform (STFT) and wavelet transform (WT). STFT method provides better performance to detect long-period earthquake whereas WT method is more available to detect short-period earthquake.

• Ocean and Polar Research
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• v.36 no.2
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• pp.145-156
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• 2014

Macrobenthic biodiversity in the rocky intertidal areas of the Tae-an region, Republic of Korea, has decreased since the Hebei Spirit oil spill in December 2007. We aimed to investigate ecological roles of Pacific oyster (Crassostrea gigas) because recruitment and growth of oysters are critical to the recovery of damaged rocky shore ecosystem. We surveyed two sites monthly: natural rocky substrate and farming substrate, from July 2012 to January 2013 to identify and compare the changes in macrobenthic fauna. The abundance of young oysters was higher at the natural site. On the other hand, the mean height of oyster on the farming substrate was more than twice as great. The abundance of oyster at the natural site increased until October and then continuously decreased until end of study period. However, the abundance of oyster at the farming site constantly decreased from the beginning of study period. These different growth patterns might be attributable to spatial competition between oyster and a barnacle species (Balanus albicostatus) and environmental factors. At the natural site, physical stress factors including dramatic temperature changes and desiccation a few of the major factors limiting growth during aerial exposure. In addition, motile macrobenthos could be detrimental to oysters because they interrupt filter-feeding activities and hence hamper the growth of oysters. We show the higher recruitment of oysters at the natural site and healthy growth in the farming substrate are due to complicated differences in physical and biological stress factors.

• Journal of architectural history
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• v.19 no.6
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• pp.137-153
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• 2010

Jeongrimsaji as temple remains of Baekje Sabi period, its re-excavation has been carried three times in full scale. As a result, the buildings in left and right of lecture hall was largely identified in 3 forms. First, layout of small buildings in left and right of lecture hall. Second, layput of corridor in left and right of lecture hall. Third, layout of construction site in the north of corridor in left and right of lecture hall. Above second is included into remains of Gorye, the third is included into remains of Baekje - the remains were almost ruined then. The first form and third form in above is different each other in size of buildings, form of layout, and location. It is important to investigate these points: the time of constructing the buildings; what position have the use and function of the buildings in the temple? ; transition process of layout of the Buddhist temple. In this context, of temple remains in Baekje during the 5~7th century, the cases where construction sites in left and right of lecture hall and construction site in the north of corridor are identified, have been reviewed. Based on this review, the use and function of buildings, their transition process were investigated. The survey results show that small buildings in left and right of lecture hall existed in the middle and later period of the 6th century. During the later 6th century ~ the 7th century, construction site in narrow and long square shape was located in left and right of lecture hall instead of small buildings in the north of corridor. Therefore, it is identified that the aforementioned thing is earlier stage and the latter thing is later stage.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.5
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• pp.233-247
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• 2024

The damage to structures during an earthquake can be varied depending on the frequency characteristics of seismic waves and the geological properties of the ground. Therefore, considering such attributes in the design ground motions is crucial. The Korean seismic design standard (KDS 17 10 00) provides design response spectra for various ground classifications. If required for time-domain analysis, ground motion time series can be either selected and adjusted from motions recorded at rock sites in intraplate regions or artificially synthesized. Ground motion time series at soil sites should be obtained from site response analysis. However, in practice, selecting suitable ground motion records is challenging due to the overall lack of large earthquakes in intraplate regions, and artificially synthesized time series often leads to unrealistic responses of structures. As an alternative approach, this study provides a case study of generating ground motion time series based on the hybrid broadband ground motion simulation of selected scenario earthquakes at sites in the Nakdonggang delta region. This research is significant as it provides a novel method for generating ground motion time series that can be used in seismic design and response analysis. For large-magnitude earthquake scenarios close to the epicenter, the simulated response spectra surpassed the 1000-year design response spectra in some specific frequency ranges. Subsequently, the acceleration time series at each location were used as input motions to perform nonlinear 1D site response analysis through the PySeismoSoil Package to account for the site response characteristics at each location. The results of the study revealed a tendency to amplify ground motion in the mid to long-period range in most places within the study area. Additionally, significant amplification in the short-period range was observed in some locations characterized by a thin soil layer and relatively high shear wave velocity soil near the upper bedrock.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.3
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• pp.88-94
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• 2004

Hemifacial spasm is painless uncommon disorder characterized by involuntary paroxysmal movement of one side face. In the treatment of hemifacial spasm, the Western operation or non-operation therapy has many side effect such as hearing loss, exudative otitis media, facial paralysis etc. So we studied mainly the effect of cause, treatment frequency, diseased part of 29 cases with hemifacial spasm for effective clicical application of oriental medicine. The results of study are as follow; 1. It shows more female patients than male patients, and mostly patients in their forties. 2. The diseased part is shown more on left side than right side, and the left side hemifacial spasm is cured more effective. 3. The causes of hemifacial spasm are mainly stress, ignorance, overwork, and the stress, a cold are more effective causes than ignorance in. 4. The disease period is mainly within six months, and that period is the most effective time. 5. The palpebral site is the most frequent site, ineffective site. 6. The effect go with the treatment frequency is not available. 7. There is a 55 percent improvement of 29 cases.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.62-70
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• 2011

This study was conducted to evaluate the performance of soil-cement walls (SCWs) to control leachate from a leaking landfill site. Tracer tests revealed that the SCW was effective to control groundwater seepage. Approximately two-months of curing period appeared to be sufficient to ensure thorough containment of landfill leachate, although a three-week period was not enough. The water quality of the monitoring wells after construction of the SCWs met the groundwater quality standard of the korean Waste Management Act, except for bacteria and coliform groups. Also an analysis of a spring water around the landfill showed that the concentrations of ammonia, inorganic nitrogen and soluble manganese which had been common contaminants in the spring water decreased dramatically after constructing the walls. Therefore, the results suggested that a SCW can be an attractive method to control leachate from a leaking landfill site.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.33-44
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• 2015

Domestic plant construction sites have a tendency to become bigger, more various and complicated. Moreover frequency of industrial incident is increasing due to short project period, coexistence work condition and using heavy construction equipment. Installing safety facilities and safety training contribute to prevent incident. But mostly incident happens due to workers' unsafe action and wrong work method. Technically, it is very difficult for us to closely manage workers preventing incident. Therefore, the role of foreman who ordinarily works together with his workers is considered more important. Specific execution plan was drawn through industrial incident statistics from Ministry of Labor and questionnaire survey to interest parties(supervisor, safety staff and foreman). If foreman has raised sense of belonging and responsibility by conducting practical safety training for his workers, manages job site and receives proper compensation for these roles, it will be expected that it fully influences incident decrease.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.10
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• pp.45-54
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• 2018

The purpose of the research is to track the morphological transformation of apartment complex sites in Busan, especially focusing on building arrangement on apartment complex sites. Though there have been numerous studies regarding apartment housing, only few studies have been performed about the building arrangement. The arrangement has been poorly treated and not well disclosed as compared with other apartment-based research such as form of residential towers, floor plan, etc. The building arrangement is one of the most critical decisions at the early design stage and is affected by numerous social aspects such as building/zoning code, market demand, cultural preference, etc. Thus, the transformation of the arrangement may provide the hint for the change of socio-cultural demands of apartment housing. The research has been done on the existing 269 apartment complexes which have been built through 2016 in Busan. There are three categories set for analysis: relationship between buildings, relation between road and buildings, and the building arrangement along site perimeter. The result shows that significant change has occurred since 2000s; the arrangement has become diverse from three types to seven types. The early model of parallel or lattice types have been dominant until 2000, but the skewed one replaced the parallel or lattice types in Period V and Period VI, which is from 2001 through 2016.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.4
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• pp.257-268
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• 2016

In the companion papers (I, II), site-specific response analyses were performed at more than 300 domestic sites and a new site classification system and design response spectra (DRS) were proposed using the results of the site-specific response analyses. In this paper, the proposed site classification system and the design response spectra are compared with those in other seismic codes and verified by different methods. Firstly, the design response spectra are compared with the design response spectra in Eurocode 8, KBC 2016 and MOCT 1997 to estimate quantitative differences and general trends. Secondly, site-specific response analyses are carried out using $V_S$-profiles obtained using field seismic tests and the results are compared with the proposed DRS in order to reduce the uncertainty in using the SPT-N value in site-specific response analyses in the companion paper (I). In addition, site coefficients from real earthquake records measured in Korean peninsula are used to compare with the proposed site coefficients. Finally, dynamic centrifuge tests are also performed to simulate the representative Korean site conditions, such as shallow depth to bedrock and short-period amplification characteristics. The overall results showed that the proposed site classification system and design response spectra reasonably represented the site amplification characteristic of shallow bedrock condition in Korea.