• Survey Research
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• v.7 no.2
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• pp.97-122
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• 2006

Korean Longitudinal Study of Ageing(KLoSA)', launched in 2006, has developed a research network with 'Health and Retirement Study(HRS, US),' Studies on Health and Retirement in Europe(SHARE, EU),' and 'English Longitudinal Study of Ageing(ELSA, UK)'and tried to construct a mega data library. The KLoSA team has designed their research with focusing on the following three points, in order to use KLoSA for international comparative studies. First, KLoSA shares the key research areas such as family structure, health, employment, income, asset, subjective expectations with the comparable studies. Second, KLoSA team has developed the instrument to reflect the Korean culture and institutions. They considered the institutional characteristics in public pension and health care system and in employment practices. They also counted the cultural conventions in family life such as financial management and care exchange, Finally, KLoSA tries to capture the psychological characteristics of the Korean elderly by making the measurement scales more understandable.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.46-50
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• 2015

The cable degradation process is largely divided into three steps; Step 1 : Thermal degradation, Step 2 : Weibull degradation, Step 3 : Partial discharge. it is progress in step order. This article aims to explain the process of cable degradation using the method of insulation resistance and accordingly to compose and manufacture a system of measuring the life of electrical cable. Before measuring the insulation resistance, a system of measuring the temperature and current of cables was made, and the established system was installed for test on the site of a power plant to collect the measured data. The current sensor was used TFC30P80A-CL420, and temperature sensor was used the DK-1270 PT100 sensor as RTD sensor. When measured the temperature and the load current at the same position, was confirmed that in case of the load current value was high, also temperature value high. Therefore, the correlation between load currents and temperature was verified, and the analysis of diagnostic data was evaluated, which could be utilized in identifying the fault condition of cable systems.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1233-1241
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• 2020

Objective: The present investigation was aimed to explore the potential of lactobacilli for conjugated linoleic acid (CLA) production, isolated from rumen fluid samples of lactating goats. Methods: A total of 64 isolates of lactobacilli were obtained using deMan-Rogosa-Sharpe (MRS) agar from rumen fluid of goats and further subjected to morphological and biochemical characterizations. Isolates found as gram-positive, catalase negative rods were presumptively identified as Lactobacillus species and further confirmed by genus specific polymerase chain reaction (PCR). The phylogenetic tree was constructed from the nucleotide sequences using MEGA6. Results: Out of the 64 isolates, 23 isolates were observed positive for CLA production by linoleate isomerase gene-based amplification and quantitatively by UV-spectrophotometric assay for the conversion of linoleic acid to CLA as well as gas chromatography-based assay. In all Lactobacillus species cis9, trans11 isomer was observed as the most predominant CLA isomer. These positive isolates were identified by 16S rRNA gene-based PCR sequencing and identified to be different species of L. ingluviei (2), L.salivarius (2), L. curvatus (15), and L. sakei (4). Conclusion: The findings of the present study concluded that lactic acid bacteria isolated from ruminal fluid samples of goat have the potential to produce bioactive CLA and may be applied as a direct fed microbial to enhance the nutraceutical value of animal food products.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.3
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• pp.255-266
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• 2010

In high-rise buildings, an outrigger system is frequently used as a resisting system for lateral loads. Since the outriggers tie exterior columns and an interior core, exterior columns can participate in the lateral load resisting system and the structural resistance capacity can be increased. However, the outriggers contribute for controlling gravity loads as well as lateral loads. The flows of gravity loads can be changed by the members of outriggers, for the purposes of transferring loads to mega-columns, distributing gravity loads equally among vertical members of columns, walls, or piles, minimizing differential settlements in a foundation system, and so on. In this study, by computational structural analyses of high-rise buildings over 100 floors, the effects of outriggers on controlling gravity loads are analyzed. Analyses for 3-dimensional models with or without outrigger members are performed, and then the gravity load distributions in columns and piles and foundation settlements are analyzed. Also, the effects of outriggers on gravity load controls during construction stages as well as after construction are included.

• Land and Housing Review
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• v.2 no.1
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• pp.47-52
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• 2011

Recent advances of technology in materials science have made it easy to respond to user's needs on high performance steel in civil and building structures. The high-performance and high-strength steel are required for large scale structure and high-rise building to have high-strength, high fracture toughness and better weldability etc. Therefore development of 600MPa class steel for mega structure is necessary. high strength steels, however, may have mechanical properties that are significantly different from those of the conventional steels. The application of high-strength steels to building structures should be reviewed as to whether inelastic behavior equivalent to that of conventional steels can be attained or not. This study researched the structural behavior of high strength circular tubes compression and under flexure. Three column tests and three flexural tests were carried out. The suitability of existing design formulae(KBC 2009) and the structural behavior were investigated through these columns and beams with various types.

• Land and Housing Review
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• v.2 no.1
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• pp.1-8
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• 2011

During the 1990's, five new towns were constructed around Seoul such as Bun-Dang and Il-San. These new towns are very popular since they were created based on systemic urban planning and they provide various residential amenities. Many people consider them livable cities. Taking such advantages, other small-scale new public and private developments continued around those new towns and consequently created 'agglomerated region with new development'. The most representative area is Bun-Dang and north-western Yong-In area which are formed along the Seoul-Busan expressway. This area is a mega-community having more than one million residents in 2005.Judging from recent development trends in the Seoul metropolitan area, it is expected that the formation of other 'agglomerated region with new development' would be continued for the time being. This study is aimed to analyze the residential environment of Bun-Dang and north-western Yong-In and find implications to the management of 'agglomerated region with new development'. The relevant existing studies have their limits, only focusing on analyzing current conditions and pointing out current problems. This study could be differentiated from the existing analyses in that it conducted comprehensive analyses on various factors that constitute urban residential environment. The conclusion of this study was derived from diverse analyses of current development condition, residential sites, regional transportation, awareness of residents, and oversee cases.

• Atmosphere
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• v.24 no.2
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• The Journal of the Korea Contents Association
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• v.10 no.1
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• pp.138-146
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• 2010

Currently mobile phones possess the new features including the control interface provided with an ease, an intuition, and a variety and the display ensured for wide area. Mobile phones mounted with the touch screen release actively due to such strengths. This is the mega trend of the development of the latest mobile game. Mobile games set to the past keypad input system have changed for adaptation in the input environment and the progressive development. Consequently it is necessary to research for 'Touch User Interface(TUI)' of mobile games fixed into input environment by "Touch screen". This study have concreted the application method of touch game through the comparison analysis with the past game and implemented touch mobile game based on usability for ten touch mobile game titles released from the inside and outside of the country in oder to apply the touch interface fixed in the game to the hand-hold device with the function of touch interface. The result of this study have two implications. First it enhances the playability and diversity of game genre restricted by reason of the limitation of the past keypad input device. Second, it utilizes the basis for the standard of the interface of the touch mobile game by genre.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.24.1-24.12
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• 2018

Objectives: The aim of this in vitro study was to evaluate the biocompatibility of newly proposed root-end filling materials, Biodentine, Micro-Mega mineral trioxide aggregate (MM-MTA), polymethylmethacrylate (PMMA) bone cement, and Smart Dentin Replacement (SDR), in comparison with contemporary root-end filling materials, intermediate restorative material (IRM), Dyract compomer, ProRoot MTA (PMTA), and Vitrebond, using human periodontal ligament (hPDL) fibroblasts. Materials and Methods: Ten discs from each material were fabricated in sterile Teflon molds and 24-hour eluates were obtained from each root-end filling material in cell culture media after 1- or 3-day setting. hPDL fibroblasts were plated at a density of $5{\times}10^3/well$, and were incubated for 24 hours with 1:1, 1:2, 1:4, and 1:8 dilutions of eluates. Cell viability was evaluated by XTT assay. Data was statistically analysed. Apoptotic/necrotic activity of PDL cells exposed to material eluates was established by flow cytometry. Results: The Vitrebond and IRM were significantly more cytotoxic than the other root-end filling materials (p < 0.05). Those cells exposed to the Biodentine and Dyract compomer eluates showed the highest survival rates (p < 0.05), while the PMTA, MM-MTA, SDR, and PMMA groups exhibited similar cell viabilities. Three-day samples were more cytotoxic than 1-day samples (p < 0.05). Eluates from the cements at 1:1 dilution were significantly more cytotoxic (p < 0.05). Vitrebond induced cell necrosis as indicated by flow cytometry. Conclusions: This in vitro study demonstrated that Biodentine and Compomer were more biocompatible than the other root-end filling materials. Vitrebond eluate caused necrotic cell death.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.661-664
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• 2008

As architectures have recently become high-risers and megastructured, stable high strength products have been ensured. Accordingly, use of precast concrete accouplement has been increased in order to facilitate air compression and rationalize construction. Since not only external heating but also internal temperature rise caused by the accumulation of cement hydration heat in manufacturing process, precast concrete members with large cross-section used for high-rise mega-structure's columns and beams may exhibit different temperature history compared to the precast concrete members for wall and sub-floor with relatively small cross-sections. Therefore, this study aims to elucidate the characteristics of temperature history of mass concrete members cast with high-strength concrete for precast concrete application. In this study, large cross-sectional precast concrete mock-up, unit cement quantity, and temperature histories in manufacturing precast concrete member under different curing condition were inclusively investigated.