• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.566-576
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• 2018

As the weapon systems of the Korean Army possess massive firepower and multiple functions, the improvement of their quality through reliability prediction is becoming increasingly important. Currently, the reliability prediction of the weapon systems of the Korean Army is a difficult process, because it is conducted by naively calculating the reliability of their constituent parts. Recently, as various studies using accumulated data are undertaken across various industries, the defense industry is also attempting to analyze the Dark Data which have been accumulated but not yet used. Therefore, it is necessary to apply Post-Logistics Support (PLS) data in order to improve the reliability of the weapon systems and, for this purpose, the Korean Army needs to conduct diverse studies. Especially, the PLS data in the defense industry is very useful for reliability prediction, because the data on the defects reported after the development of the weapon systems are accumulated in this phase. This study examines the existing reliability prediction method conducted using the component parts and proposes a new reliability prediction method using PLS data. This framework can ultimately contribute to improve the prediction accuracy and quality of the weapon systems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.497-512
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• 2017

Temporal and spatial variations in surface water temperature were studied using data from temperature monitoring buoys deployed at 47 stations around Boryeong from 2011-2012 off the west coast of Korea. Temperature fluctuations are predominant at diurnal and semidiurnal periods for all seasons, and their amplitudes are large in spring and summer but small in autumn. The maximum annual change in air temperature takes place on August 2nd and August 22th for water temperature, which means the phase for air temperature precedes water temperature by 20 days. The diurnal period of water temperature fluctuation is predominant around Daecheon and Muchangpo Harbors, with the semidiurnal period around Wonsan Island, and the shallow water constituent period on the estuary around Daecheon River. On the whole, air and water temperatures fluctuate with wind. Spectral analyses of temperature records show significant peaks at the 0.5, 1 and 15 day marks with 7-10 day periods of predominant fluctuations. Cross-correlation analyses for the temperature fluctuation show that the waters around Boryeong can be classified into four areas: a mixed water zone around the southeast side of Wonsan Island, an off-shore area to the west, an off-shore area to the south and a coastal area along the shore from Song Island to Muchangpo Harbor.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.396-403
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• 2011

Ceramides (Cer) comprise the major constituent of sphingolipids in the epidermis and are known to play diverse roles in the outermost layers of the skin including water retention and provision of a physical barrier. In addition, they can be hydrolyzed into free sphingoid bases such as $C_{18}$ sphingosine (SO) and $C_{18}$ sphinganine (SA) or can be further metabolized to $C_{18}$ So-1-phosphate (S1P) and $C_{18}$ Sa-1-phosphate (Sa1P) in keratinocytes. The significance of ceramide metabolites emerged from studies reporting altered levels of SO and SA in skin disorders and the role of S1P and Sa1P as signaling lipids. However, the overall metabolism of sphingoid bases and their phosphates during keratinocyte differentiation remains not fully understood. Therefore, in this study, we analyzed these Cer metabolites in the process of keratinocyte differentiation. Three distinct keratinocyte differentiation stages were prepared using 0.07 mM calcium (Ca$^{2+}$) (proliferation stage), 1.2 mM Ca$^{2+}$ (early differentiation stage) in serum-free medium, or serum-containing medium with vitamin C (50 ${\mu}L$/mL) (late differentiation stage). Serum-containing medium was also used to determine whether vitamin C increases the concentrations of sphingoid bases and their phosphates. The production of sphingoid bases and their phosphates after hydrolysis by alkaline phosphatase was determined using high-performance liquid chromatography. Compared to cells treated with 0.07 mM Ca$^{2+}$, levels of SO, SA, S1P, and SA1P were not altered after treatment with 1.2 mM Ca$^{2+}$. However, in keratinocytes cultured in serum-containing medium with vitamin C, levels of SO, SA, S1P, and SA1P were dramatically higher than those in 0.07- and l.2-mM Ca$^{2+}$-treated cells; however, compared to serum-containing medium alone, vitamin C did not significantly enhance their production. Taken together, we demonstrate that late differentiation induced by vitamin C and serum was accompanied by dramatic increases in the concentration of sphingoid bases and their phosphates, although vitamin C alone had no effect on their production.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.318-328
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• 2017

In order to provide basic data for the ecological management of forest vegetation in Southern Naeyeon Mountains, A total of 149 sample plots were selected and vegetation survey was carried out by the phytosociological method of the ZM school to classify vegetation types and to grasp ecological characteristics. The forest vegetation was divided into 10 types in terms of species composition, and had a unit hierarchy of 2 community groups, 4 communities, 6 sub-communities and 6 variants. A total of 19 types of physiognomic vegetation were identified based on uppermost dominant species, of which 18 were natural vegetation and 1 was artificial vegetation. As a result of the analysis of the importance values of constituent species, Quercus mongolica, a potentially natural vegetation element, was found to be relatively more important in most stands than other species, and excluding the artificial interference, most of the areas except for some sites would be changed to Q. mongolica forest. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. As a result, natural vegetation accounted for 98.2%, the number of vegetation patches was 733 and the average area per patch 3.93ha.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.1
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• pp.118-134
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• 2013

This paper analyzes the pubic nature of New Genre Public Arts. It is very sensitive to the social issues and supports democracy and communities with the diverse civic participation. Therefore, it is be widely known without doubt that new genre public arts is more public in nature compared to the previous public arts. This research observes the practices of new genre public art and focuses on the problems of the revealing nature of new genre public art through the analysis of the interrelations among government, artists, and the residents by through observation on the , Seoul City Gallery project from October 2008 to January 2009. The implementation of the project is divided into three constituent parts: local government for funding, artists for planning and implementing, and residents. Local government supports and commands the public art works to create more competitive and harmonious city. Artists emphasize the revitalization of community and take the residents as the passive objects of enlightenment. Whereas, the residents hope to use the funds to improve economic conditions. Artists accept the top-down commands of government, whereas residents tend to passively participate and become objects for enlightenment by artists, after all, might be alienated by the project. These kinds of communications and relationships raise the issue of the possibility of failure of public arts projects.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.26-30
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• 2020

This study was undertaken to determine the characteristics of xanthoangelol, the major chalcone constituent derived from the extracts of different parts of Lespedeza bicolor. Xanthoangelol was isolated from the root extract using column chromatography and used as a standard for quantitative analysis. The structure of the isolated compound was established based on spectroscopic evidence. The HPLC-DAD method was validated for specificity, linearity, precision, accuracy, limit of detection, and limit of quantitation. The calibration curve of xanthoangelol had significant linearity (R²>0.9999). Limit of detection and limit of quantitation 0.018 and 0.059 ㎍/mL, respectively. The relative standard deviation values of precision test, and intra- and inter-day tests were less than 0.22 and 0.40%, respectively. In the recovery test, the accuracy ranged from 98.98-102.78% with RSD values less than 0.13%. The method validation parameters indicate the applicability of the HPLC method for quality control of food or drug formulations containing L. bicolor.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.503-510
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• 2020

Concrete is one of the most widely used materials as the shielding structures of a nuclear facilities. It is also the most generated radioactive waste in quantity while dismantling facilities. Since the concrete captures neutrons and generates various radionuclides, radiation measurement and analysis of the sample was fulfilled prior to dismantle facilities. An HPGe detector is used in general for the radiation measurement, and effective correction factors such as geometrical correction factor, self-absorption correction, and absolute detector efficiency have to be applied to the measured data to decide exact radioactivity of the sample. Correction factors are obtained by measuring data using a standard source with the same geometry and chemical states as the sample under the same measurement conditions. However, it is very difficult to prepare standard concrete sources because concrete is limited in pretreatment due to various constituent materials and high density. In addition, the concrete sample obtained by core drill is a volumetric source, which requires geometric correction for sample diameter and self absorption correction for sample density. Therefore in recent years, many researchers are working on the calculation of effective correction factors using Monte carlo simulation instead of measuring them using a standard source. In this study we calculated, using Geant4, one of the Monte carlo codes, the correction factors for the various diameter and density of the concrete core sample at the gamma ray energy emitted from the nuclides ¹⁵²Eu and ⁶⁰Co, which are the most generated in radioactive concrete.

• Journal of Korea Game Society
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• v.9 no.6
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• pp.45-56
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• 2009

This Study has limited our scope to the study of satisfaction factor. Due to the extensiveness of fun factors of games. We had identified satisfaction factors through investigating various theories based on funology. Then, we have directly applied the satisfaction factors to games in order to define the satisfaction factors of online FPS game. Then, we have applied the satisfaction factors on to four online games, at the first phase of the study. We interviewed a group of online FPS game experts to identify the constituent elements of the factors and concluded the second phase of our investigation based on the results from the first and second phases, we have conducted a survey to verify the hypothesis. We have verified the reciprocal relationship between the satisfaction factors and game popularity by conducting a multiple regression analysis on the survey results. To conclude, there is a correlation between online FPS games and the satisfaction factors; the satisfaction factors cause the users to be absorbed into the game and to enjoy it for a long period of time.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1356-1365
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• 2020

In this study, the extracts of Hydrangea macrophylla (H. macrophylla) flowers were investigated for the anti-oxidative and anti-inflammatory activities, and their active constituents were identified. The anti-oxidative effects were tested by DPPH and ABTS⁺ assays. To evaluate anti-inflammatory activities, LPS-induced RAW264.7 cells were examined. Among the extracts, the ethyl acetate fraction showed potent radical scavenging activities and inhibition of nitric oxide (NO) production. Chromatographic purification of the extract led to isolation of the compounds; hydrangenol (1), prunin (2) and astragalin (3). The chemical structures of the constituents were elucidated based on spectroscopic data including NMR spectra, as well as comparison of the data in the literature values. Quantitative analysis by high pressure liquid chromatography (HPLC) determined hydrangenol (1) as the major constituent. Isolated compounds 1-3 decreased the NO level without causing cell toxicities. Based on these results, it was suggested that the extract from H. macrophylla flowers could be potentially applicable as an anti-oxidative and/or anti-inflammatory ingredients.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.23-32
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• 2018

Noerok ia a green pigment used in Joseon dynasty, and its main usage was for forming foundation layers of Dancheong, the ornamental paintings on the surface of traditional buildings in Korea, such as the Daeung-jeon(main hall) of Bulguk-sa temple. In this research, we investigated the mineralogical characteristic changes of Noerok, a traditional Korean pigment, depending on its firing temperature. The Noerok that we experimented on was mined from Noeseong Mountain, Pohang where it is locally reserved. The major composition mineral is Celadonite, and the main constituent elements are Fe, Si, K and Mg, that refers to the existence of Fe-rich mica. As a result of phased firing experiment from $105^{\circ}C$ to $1000^{\circ}C$, the color was changed from green to pale green, then to brown, and finally to red in order. In the thermal analysis, endothermic reaction induced by the dehydration of crystalline water was confirmed at around $616^{\circ}C$. In the mineralogical change, the crystal surface [($11{\bar{1}}$) and ($02{\bar{1}}$)] of the mineral collapsed at temperatures above $600^{\circ}C$, and iron oxide was formed at $1000^{\circ}C$ or higher. Therefore, it is estimated that the crystallization temperature of Noerok is below $600^{\circ}C$, and it is also considered that it has undergone the alteration phase up to stage I, based on the presence of only a celadonite.