• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.339-349
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• 2007

For various types of the Pungchon limestone, diverse mineral characters of the limestone including their size and morphology are investigated by using of ELS and SEM to examine the possibility of application as fillers to paper industry. Also, the measurement of zeta potential and the evaluation of coagulation properties in calcite suspension was made for fine powders of the limestone to examine the applicability and efficiency in wet-papermaking process. Fine powder of the Pungchon lime-stone, largely controlled by original mineral characters of ore in mineralogical aspects, exhibits some-what different trend in particle morphology according to ore types, and thereby, the size distribution, zeta potential and coagulation properties also become different. The examined whiteness, brightness, opacity and sheet strength in hand sheet also show remarkable differences according to ore types. These are seemed to be basically due to the results of combined effects of whiteness, site distribution, refractive index, and morphology of the limestone powder on the properties of hand sheet. Considering the investigated results, all types of the Pungchon limestone appear to be sufficiently applicable to paper industry. Especially, the mega-crystalline calcite type is evaluated to be overall suitable for the purpose of paper industry due to the higher values in whiteness and brightness. In addition the fine powder of micro-crystalline calcite type is assessed particularly to have a good quality in sheet strength by virtue of irregular particle shape.

• Journal of Conservation Science
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• v.37 no.5
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• pp.545-556
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• 2021

In this study, we aimed to elucidate the materialistic characteristics of 11 pieces of earthenware belonging to the Neolithic and Bronze Age excavated from Jeongseon Auraji, South Korea. As a result, the chemical composition of earthenwares belonging to the early Bronze Age was distributed in the intermediate area between the Neolithic and Bronze Age earthenwares, but no significant difference was confirmed based on their manufacturing period. Upon comparison, the earthenwares excavated from Jeongseon Auraji site were found to comprise less acidic components than those excavated from Yeongdong, and are characterized by the alkaline components depending on the excavated site. In the rare earth elements distribution pattern, all the analyzed earthenwares exhibited similar pattern, confirming that the raw materials present in the clay were the same. As a result of microstructure analysis, the clay particles and voids were found to be irregularly distributed in the analyzed earthenwares. Neolithic earthenwares exhibited many irregular voids, and an arrangement of aluminosilicate, including feldspar, was observed along with the clay substrate. Furthermore, we confirmed that the empty space in early Bronze Age earthenwares was filled with fine particles and cube crystals. Moreover, the main mineral phase of earthenwares excavated from Jeongseon Auraji exhibited similar composition, and therefore, there was no significant difference in the firing temperature of these earthenwares. The firing temperature of the earthenwares ranged from 750 to 850℃.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.246-257
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• 2018

The purpose of this study was to investigate the effects of physical health status and social support on depression and quality of life among the elderly in G City. This is a descriptive research study of 497 elderly residents in 45 senior citizen centers in G city; the data were collected from March 5 to 30, 2018. Data were analyzed using the IBM SPSS/win 24.0 program by t-test, ANOVA and multiple regression analysis. In physical health status, the chronic disease score was $1.35{\pm}0.91$, the functional status score was $1.80{\pm}4.45$, and the subjective health score was $3.14{\pm}1.13$. The average score for social support in the emotional network was $5.71{\pm}1.13$. In the sub-region of the social network, the score for frequency of contact with relatives was $2.92{\pm}1.31$, that for contact with friends was $3.18{\pm}0.98$, and that for social participation was $0.68{\pm}0.82$. In the multiple regression analysis of factors affecting depression and quality of life, the explanatory power of physical health status and quality of life was 45.5% and 21.1%, respectively. The explanatory power of depression based on social support and quality of life was 46.7% and 27.5%, respectively. This study indicates that physical health status and social support affect depression and quality of life. Therefore, programs should be developed to increase the physical health status and social support and thus improve the quality of life of the elderly in the community.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.1-12
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• 2010

The objective of this study was to examine the hydrogeochemical and microbiological characteristics for stable maintenance of coastal LPG storage cavern. Cavern seepage water and groundwater in the vicinity of the LPG storage cavern were sampled and analyzed (February, May, August and October 2007). Groundwater samples of propane cavern showed high pHs of 8.1~12.4 due to dissolution of cement grouting materials that had been applied during the well and cavern construction. The EC values showed distinctive seasonal variation. The negative ORP indicated reduced condition. The seepage and surrounding groundwater are classified as Na-Cl type, which represents seawater effects. All of aerobic bacteria, anaerobic bacteria, slime forming bacteria and sulfate reducing bacteria were less than 500 CFU/mL, which indicated that there was no abrupt increase of bacteria in the cavern. Therefore there exist no hydrochemical symptoms to indicate unstable conditions of the cavern operation. However, regular and continuous monitoring is essentially required.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.13-20
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• 2009

Recently, as traffic flooding attacks such as DoS/DDoS and Internet Worm have posed devastating threats to network services, rapid detection and proper response mechanisms are the major concern for secure and reliable network services. However, most of the current Intrusion Detection Systems (IDSs) focus on detail analysis of packet data, which results in late detection and a high system burden to cope with high-speed network traffic. In this paper we propose an SNMP-based lightweight and fast detection algorithm for traffic flooding attacks, which minimizes the processing and network overhead of the detection system, minimizes the detection time, and provides high detection rate. The attack detection algorithm consists of three consecutive stages. The first stage determines the detection timing using the update interval of SNMP MIB. The second stage analyzes attack symptoms based on correlations of MIB data. The third stage determines whether an attack occurs or not and figure out the attack type in case of attack.

• Korean Journal of Community Nutrition
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• v.15 no.4
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• pp.445-459
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• 2010

This study was done to analyze the chronic diseases prevalence and dietary intake status according to the health related quality of life and to identify its significant properties. This study was conducted based on 2906 subjects ranging from 20~64 years old, out of 9704 total subjects from the 4th Korean National Health and Nutrition Survey in 2008. The average quality of life (QL) score was 0.915, where 983 subjects were below the average (low QL group) and 1923 subjects were above (high QL group). In the high QL group, there was more likely to be young, male, and with higher income and education. For high QL group, the self-related health score was high, and the subjective stress level was low. The prevalence of diabetes was significantly higher in the low QL group and anthropometric and biochemical measures were not shown differences between the two groups but waist circumference was significantly higher in the low QL group. The QL score was significantly negative correlated with the waist circumference and the body mass index. As for the recognition rate of Nutrition Guideline, there were no significant differences but high QL group had higher scores in "Eat a variety of foods", "Avoid too much Sodium", and "Enjoy meals and Eating a breakfast". Carbohydrate intake was significantly lower in the high QL group than in low QL group and the high QL group showed higher intake in legumes, meat and poultry, fruits, daily products and beverages. Overall results suggest that increased diabetes prevalence in people with low quality of life might be affected by the diets based on high carbohydrate, increased waist circumference, and lower rate of practice nutritional guideline.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.205-212
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• 2023

In the modern society, the extreme weather caused by climate change has brought about exceptional damage in succession over the world due to the use of fossil fuels, and infectious diseases such as COVID-19 worsen the quality of human life. It is urgently necessary to reduce green-house gas and use new renewable energy. The global environmental pollution should be decreased by reducing the use of fossil fuels and using new renewable energy. This paper suggests a system which can function for the environment of four seasons, safety and communication, through the photovoltaic power-based intelligent CCTV, internet and WiFi, and cooling and heating systems, and can optimally manage power, through the real-time monitoring of the production and the consumption of the photovoltaic power. It suggests a hybrid generation system supporting diesel generation without discontinuation in the case of emergency such as system power outage caused by cold waves, typhoons and natural disasters in which the photovoltaic power generating system cannot be used.

• Journal of Korean Dental Hygiene Science
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• v.5 no.2
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• pp.73-83
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• 2022

Background: This study was aimed at reducing depression and improving the quality of life and oral health of the elderly Koreans by elucidating the effect of depression on their life quality and oral health. Methods: Original data from the 8th National Health and Nutrition Survey (2019) were analyzed and implemented. The elderly (age≥65years) Koreans were enrolled. The oral health status was determined using the Decayed, Missing, Filled Teeth (DMFT) index and subjective self-report. The quality of life was quantified as the sum of score of each item in the Euro Qol-5 dimension (EQ-5D) and Health-related Quality of Life Instrument with 8 Items (HINT-8). The t-test, one-way analysis of variance, correlation analysis, and multiple regression analysis were performed to statistically compare the quality of life, oral health status, and oral health status according to the depression status. Results: EQ-5D and HINT-8 scores differed significantly with the history of depression, current depression, stress perception, depression for 2 weeks, and annual suicidal intention (p≤0.05). The DMFT index score differed significantly with the depression diagnosis and depression for 2 weeks (p≤0.05). EQ-5D, HINT-8, and DMFT index differed significantly with all oral health behavior variables (p≤ 0.05). Conclusions: The results of this study could serve as a basis to formulate oral health programs for the elderly to reduce depression and improve the quality of life.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.21-28
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• 2009

Purpose: The purpose of this study was to compare the wear characteristics of human enamel opposing 2 heat-pressed ceramics (e.max Press and Empress Esthetic), conventional feldspathic porcelain (Ceramco 3) and type III gold alloy. Material and methods: Intact cusps of extracted premolars were used for enamel specimens. Five disk samples were made for each of two heat-pressed ceramics groups, conventional feldspathic porcelain group and type III gold alloy group. Wear tests were conducted in distilled water using a pin-on-disk tribometer. The amount of enamel wear was determined by weighing the enamel specimens before and after wear tests, and the weight was converted to volumes by average density. The wear tracks were analyzed by scanning electron microscopy and surface profilometer to elucidate the wear characteristics. Results: 1. Ceramco 3 led to the greatest amount of enamel wear followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between Ceramco 3 and Empress Esthetic (P>.05), and there were also no significant differences among Empress Esthetic, e.max Press and type III gold alloy (P>.05). 2. The average surface roughness of e.max Press after wear test was smallest followed by Empress Esthetic and Ceramco 3, but there was no significant difference between Empress Esthetic and Ceramco 3 (P>.05). 3. There were no significant differences among the depth of wear tracks of all the groups (P>.05). The group that showed the largest width of wear track was Ceramco 3 followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between e.max Press and Empress Esthetic (P>.05), and there was also no significant difference between Empress Esthetic and Ceramco 3 (P>.05). Conclusion: Within the limits of this study, heat-pressed ceramics were not more abrasive than conventional feldspathic porcelain.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.860-875
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• 2007

The purpose of this study was to investigate the seasonal variation in the mineral contents of fruits and vegetables available all the year -round. We analyzed Na, K, Mg, Ca, P, Fe Cr, Mn, Cu, Zn, Se, and Al concentrations by ICP-mass in 4 fruits and 17 vegetables items which are frequently consumed in Koreans. For Na content, fall apples showed the highest levels among 4 seasons, but fall tangerines contained the lowest amount of Na among the four seasons. Among the vegetables, the spinach, carrots, and lettuce contained relatively high amounts of Na. The K contents of cucumbers, cabbage, and zucchini were higher in the fall than in the other seasons. For Ca and Fe contents, spring strawberries, fall pears, and fall cabbage had the highest levels. The Cr contents of the apples were higher in the fall and winter than those were in the spring and summer. The strawberries contained their highest amounts of Cr, Mn, and Cu in the spring. The above results showed there are seasonal differences in the mineral contents of fruits and vegetables. Additionally, the fruits and vegetables tended to contain more minerals in the season they were harvested. Therefore, it is recommended to consume those fruits and vegetables during their harvest season.