• Korean Journal of Clinical Pharmacy
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• v.29 no.4
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• pp.238-246
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• 2019

Background: In South Korea, as an aged society, an understanding of dementia and its risk factors is important from clinical and healthcare policy perspectives. Relationship between cognitive impairment and body weight or weight changes have been reported, but these were contradictory. We have evaluated the association between weight changes and cognitive decline using national level longitudinal data. Methods: Data from the Korean Longitudinal Study of Ageing from 2006 to 2012 were used. Association between weight changes and decline in cognitive function as measured by K-MMSE (the Korean version of the Mini-mental state examination) score was assessed by multivariate logistic regression. Weight changes were calculated from 1st wave and 3rd wave survey data, and classified into five groups as stable, increases, decreases of >10%, or 5%-10%. Results: About 37% of the total participants (n=4,512) were 65 years or older. These participants made up the largest proportion of the groups with weight change exceeding 10%. Multivariate logistic regression analyses revealed that weight changes exceeding 10% (10% increase vs stable, adjusted OR [aOR] 1.47, 95% confidence interval (CI) 1.11-1.95; 10% decrease vs stable, aOR 1.44, 95% CI 1.11-1.88) were significant predictive factors for decline in cognitive function. In subgroup analyses, the association between weight changes and cognitive decline was significant in males aged over 65 years and in normal BMI groups. Conclusion: Weight changes, both increases and decreases exceeding 10% of baseline, were significantly associated with declines in cognitive function among older adults in South Korea.

• Advanced Composite Materials
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• v.17 no.1
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• pp.25-40
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• 2008

The research and development in soundproof materials for preventing noise have attracted great attention due to their social impact. Noise insulation materials are especially important in the field of soundproofing. Since the insulation ability of most materials follows a mass rule, the heavy weight materials like concrete, lead and steel board are mainly used in the current noise insulation materials. To overcome some weak points in these materials, fiber reinforced composite materials with lightweight and other high performance characteristics are now being used. In this paper, innovative insulation sheet materials with carbon and/or glass fabrics and nano-silica hybrid PU resin are developed. The parameters related to sound performance, such as materials and fabric texture in base fabric, hybrid method of resin, size of silica particle and so on, are investigated. At the same time, the wave analysis code (PZFlex) is used to simulate some of experimental results. As a result, it is found that both bundle density and fabric texture in the base fabrics play an important role on the soundproof performance. Compared with the effect of base fabrics, the transmission loss in sheet materials increased more than 10 dB even though the thickness of the sample was only about 0.7 mm. The results show different values of transmission loss factor when the diameters of silica particles in coating materials changed. It is understood that the effect of the soundproof performance is different due to the change of hybrid method and the size of silica particles. Fillers occupying appropriate positions and with optimum size may achieve a better effect in soundproof performance. The effect of the particle content on the soundproof performance is confirmed, but there is a limit for the addition of the fillers. The optimization of silica content for the improvement of the sound insulation effect is important. It is observed that nano-particles will have better effect on the high soundproof performance. The sound insulation effect has been understood through a comparison between the experimental and analytical results. It is confirmed that the time-domain finite wave analysis (PZFlex) is effective for the prediction and design of soundproof performance materials. Both experimental and analytical results indicate that the developed materials have advantages in lightweight, flexibility, other mechanical properties and excellent soundproof performance.

• 한국노년학
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• v.38 no.2
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• pp.329-349
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• 2018

The objective of this study is to examine whether there are differences in participation in social activities and the effects of social activity types on the levels of happiness of the Korean older adults by age groups. The 5th wave(2014) of the Korean Longitudinal Study of Ageing (KLoSA) was used and a total of 3,273 elderly were selected from the 5th wave, who were 65 years old and older and who were not living with their offsprings. Chi-square test, ANOVA, and hierarchical multiple regression analysis were used. The rate of participation in economic activities declined with age and the levels of participation in leisure activities was higher in the young-old group in comparison to the middle- and the oldest- old groups. The levels of participation in family activities was higher in the middle- and the oldest-old groups in comparison to the young-old group. Socializing activities and religious activities measured by the frequencies of activities were not significantly different among the age groups. The results of a regression analysis of social activity types and their effects on happiness by age groups are the followings: 1) Leisure, socializing, religious, and family activities all (with the exception of economic activities) significantly affected the level of happiness of older persons in the young-old group. 2) However, only socializing and family activities in the middle-old age group, and only family activities in oldest-old group, had a statistically significant impact on the levels of happiness. These results support that the rates of participation in the five types of social activities and their effects on the levels of happiness were different by age groups. The implication of this study was to report that needs and the interests of older individuals are different by age groups based on empirical evidences.

• Korean Journal of Social Welfare Studies
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• v.42 no.4
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• pp.263-293
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• 2011

There have been many studies on the relationship between welfare states and the poverty. Yet, only a few studies have been addressed the poverty alleviation effect of public pension using difference in difference(DID). This study aims to analyze poverty alleviation effect for the old aged of public pension in 10 OECD countries using DID considering welfare states regimes. The empirical analyses are based on panel data of individuals aged 50 and over from two sources: SHARE in Europe(wave I~II) and HRS in USA(2004~2006). As a result of simple DID, this study provides evidence that the poverty rate of the old aged who has not been received the pension is increased, while the poverty rate of pensioner is sharply decreased. The anti-poverty effect of public pension using DID is 45.6% which is bigger than that of pre/post approach. The policy impact used by pre/post approach in conservative welfare regime is underestimated while those in liberal and socialist regime are overestimated. In last, GDP growth rate has not significant while public pension contributes to poverty alleviation effects of the old aged. Poverty alleviation effects of public pension are also varied with welfare state regimes. The poverty alleviation effects of public pension in conservative welfare and social democratic welfare state regime are significantly bigger than that in liberal welfare state regime.

• Information Systems Review
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• v.25 no.1
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• pp.145-164
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• 2023

The proliferation of online reviews on dining experiences has significantly affected consumers' choices of restaurants, especially overseas. Food quality, service, ambiance, and price have been identified as specific attributes for the choice of a restaurant in prior studies. In addition to these four representative attributes, cultural factors, which may also significantly impact the choice of a restaurant for tourists, in particular, have not received much attention in previous studies. This study employs the text mining technique to analyze over 10,000 online reviews of 76 Korean restaurants posted by Chinese tourists on dianping.com to explore the influence of cultural factors on the consumer's choice of restaurants in the overseas travel context. The findings reveal that "Hallyu (Korean Wave)" influences Chinese tourists' dining experiences in Korea and their satisfaction. Moreover, Korean food-related words, such as cold noodle, bibimbap, rice cake, pig trotters, and kimchi stew, appeared across all the review topics. Our findings contribute to the existing tourism and hospitality literature by identifying the critical role of cultural factors on consumers', especially tourists', satisfaction with the choice of a restaurant using text mining. The findings also provide practical guidance to restaurant owners in Korea to attract more Chinese tourists.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.4-4
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• 2008

The progress in flat panel displays over the last two decades has been astonishing. In just 20 years, the LCD-TV grew up from a 2-inch curiosity, to an industry that will sell about 120 million flat panel TV's this year, with viewing area up to 4000 times larger. That success is based on continuous innovation, especially in manufacturing processes. For the next decade to bring another doubling of the business, progress will need to continue in four major areas: Human factors, ecological impact, visual quality, and of course continued drive towards affordability. This talk will detail the technology advances that can allow this industry to meet those challenges. Human factors. Today, we adapt our lifestyle to our technology. People organize their offices, and their homes, around displays. We pass around mobile phones to share images, rather than experiencing them as a group. Billions of newspapers continue to be sold daily. Advances in flexible displays can lead to large portable displays. "New era projection" includes the handheld Pico Projectors that are already on the market, and will ultimately appear integrated in mobile phones the same way cameras do today. "Eco" impact. Today TV's are one of the top energy consumers in a U.S. home, and the fastest growing. Watching a large flat panel TV can cost twice as much as running a large refrigerator. With today's concern about energy consumption, regulations are starting to emerge worldwide to limit TV electrical use. Fortunately, good solutions exist in using light management films to eliminate bulbs, saving power without increasing cost. Going forward, LED backlights will drive another step downward. OLED displays might be the ultimate solution. Visual quality. The color of an LCD-TV is still often considered inferior to a far less expensive CRT. And almost all displays suffer from representing a three-dimensional world on a two dimensional surface. The technology to improve color is available today, and will likely move from premium sets into the mainstream as costs come down. 3D is now arriving in movie theaters worldwide, and that will drive up the demand for similar realistic images in home theaters. And the technology is emerging today for 3D representation to move beyond specialized applications into everyday use, on screens large and small. Affordability. The world takes cost-down miracles for granted in consumer electronics. Each of these other advances will be balanced with a drive for affordability, especially as the market grows in emerging countries. The other three challenges must be met without increasing cost. Putting this all together, the next few years will emphasize "eco friendly" designs, and enhanced images such as 3D. By 2013 we will start to see serious penetration by emissive technologies (OLED, high efficiency plasma, or other), with the "ultimate display" likely not in the market for a decade. Lots of opportunities for innovation remain ahead of us.

• Journal of Technologic Dentistry
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• v.32 no.2
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• pp.65-74
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• 2010

Purpose : To understand the impact on the strength or restoration force by the change of heating temperature when soldering 18-8 stainless steel round wire which is the chrome-nickel class for dental orthodontic device production. Methods : The following conclusions were made upon the results from tensile strength test, 3 point bending test, and $90^{\circ}$ bending fatigue test with 24 samples that had been applied with condition 1 (before heat treatment - natural) and condition 2 (after heat treatment - mooring 30 seconds after heating up to $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$) to ${\phi}0.4mm$, ${\phi}0.7{\beta}mm$, 18-8 stainless steel round wire (spring hard) by Jinsung Company. Results : When it was heat-treated at $900^{\circ}C$, both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low tensile strengths compared to the heat treated cases at $500^{\circ}C$ and $700^{\circ}C$ Yield strengths of both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$, as well. Upon the results of 3 point bending test, the heat treated case at $900^{\circ}C$ showed very low in both ${\phi}0.4mm$ and ${\phi}0.7mm$, compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Tensile strength of both ${\phi}0.4mm$ and ${\phi}0.7mm$ as well, showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Upon the results of $90^{\circ}$ bending fatigue test, the heat treated case at $900^{\circ}C$ showed the highest wave node resistance in both ${\phi}0.4mm$ and ${\phi}0.7mm$. Conclusion : This study concluded that heating temperature change during wire soldering impacts on the characteristics of orthodntic wire.

• Review of Culture and Economy
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• v.20 no.2
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• pp.119-147
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• 2017

This study analyzes Big Data to understand the economic influence of K-Beauty which is expected as a fast-growing industry. Because the content of K-beauty is mainly transmitted over the Internet, Big Data about K-Beauty in the database of online services can show interest and engagement in K-Beauty. The export volume of the beauty industry and the number of foreign tourist in Korea were used as dependent variables. The volume of Google search and the volume of YouTube page view were independent variables. According to the result of a multi-regression analysis, the volume of Google search of K-Beauty had a positive influence on both dependent variables, even after controlling for GDP (Gross Domestic Product) and distances between nations. When it comes to the volume of YouTube page view of K-Beauty, it had a positive relationship with the export volume of the beauty industry, whereas there was no significant relationship between the volume of YouTube page view and the number of foreign tourists. The result indicates that the content of K-Beauty has a significant impact on the beauty industry. Moreover, this empirical study shows that web search and YouTube search have a positive relationship with the economical aspect. These results can be used to discuss public relations strategy to promote K-Beauty industry.

• Journal of Climate Change Research
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• v.4 no.1
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• pp.1-10
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• 2013

This study has purpose to minimize the impact of climate change of Siheung. Vulnerability assessment was carried out for establishing the Siheung Climate Change Master Plan. Climate change vulnerability assessment analyzed using climate exposure, sensitivity and adaptive capacity indicators. A proxy variable is selected from each indicator. Meteorological data uses the RCP scenarios provided by the Meteorological Administration, and this study assumes that the same trend will continues in the future. Siheung are vulnerable to heavy rains in the flooded roads and farmland. Also, it is necessary to be careful heat wave in summer. The size and scale of the damage depends on the city's ability to respond to the impacts of climate change. It is necessary to make a adaptation plan for climate change impact assessment and vulnerability analysis. This study will be used to make Siheung Climate Change Master Plan and to determine the priority of the policy as guideline. It is expected that this study is helpful to pursue climate change vulnerability assessment of other local governments.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.57-65
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• 2022

This study simulated the shock wave propagation through the tamping material between explosives and hole wall at blasting works and verified the effect of tamping materials. The Arbitrary Lagrangian-Eulerian(ALE) method was selected to model the mixture of solid (Lagrangian) and fluid (Eulerian). The time series analysis was carried out during blasting process time. Explosives and tamping materials (air or water) were modeled with finite element mesh and the hole wall was assumed as a rigid body that can determine the propagation velocity and shock force hitting the hole wall from starting point (explosives). The numerical simulation results show that the propagation velocity and shock force in case of water were larger than those in case of air. In addition, the real site at blasting work was modeled and simulated. The rock was treated as elasto-plastic material. The results demonstrate that the instantaneous shock force was larger and the demolished block size was smaller in water than in air. On the contrary, the impact in the back side of explosives hole was smaller in water, because considerable amount of shock energy was used to demolish the rock, but the propagation of compression through solid becomes smaller due to the damping effect by rock demolition. Therefore, It can be proven that the water as the tamping media was more profitable than air.