• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.473-479
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• 2017

Due to environmental pollution, hazards of the human body, and global warning, changes in the power train of automobiles are intensifying, and the market forelectronic vehicles is rising. Also, in order to meet the stricter emission regulations forautomobiles with internal combustion engines based on fossil fuel, the proportion of after-treatments for vehicles and vessels is increasing gradually. The objective of this study is to investigate the effectsfrom additive ceric oxide ($CeO_2$) loading amounts to improve the methane ($CH_4$) and nitric oxide (NOx) abatement ability of the natural gas oxidation catalysts(NGOC) reducing toxic gases emitted from compressed natural gas (CNG) buses. Three kinds of NGOC were prepared under the following conditions: fresh and $700^{\circ}C$ for 12hr thermal aging, and the reduction performance of toxic gases was evaluated. Fresh $1Pt-3Pd-1Rh-3MgO-6CeO_2/(Al+Z)$ NGOC containing 6wt% $CeO_2$ had the highest dispersivity of palladium (Pd) with high selectivity to $CH_4$ and improved harmful gas reduction performance. The NGOC with 6wt% $CeO_2$ loaded the least decreased in the dispersivity of the noble metal, and showed the highest reduction of harmful gases due to the thermal durability of $CeO_2$.

• Physical Therapy Korea
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• v.25 no.2
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• pp.22-29
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• 2018

Background: Deficits of both ankle dorsiflexion range of motion (DFROM) and dynamic balance are shown in persons with chronic ankle instability and the elderly, with the risk of falls. Objects: This study aims to investigate the relationship between DFROM and dynamic balance in elderly subjects and young adults. Methods: Fifty-nine subjects were divided into three groups: ankle stability young group (SY), ankle instability young group (IY) and ankle stability older group (SO). We recruited three old subjects with ankle instability, but excluded them during a pilot testing due to the safety issue. DFROM was measured by weight bearing lunge test (WBLT) and dynamic balance was measured via star excursion balance test (SEBT) in anteromedial, medial, and posteromedial directions. The group differences in WBLT and SEBT and each group's correlation between WBLT and SEBT were detected using the R statistical software package. Results: The dorsiflexion range of motion was significantly different between the SY, IY, and SO groups. The SO group showed the highest DFROM and IY group showed the lowest DFROM (SY: $45.88{\pm}.66^{\circ}$, IY: $39.53{\pm}1.63^{\circ}$, SO: $47.94{\pm}.50^{\circ}$; p<.001). However, the SO group showed the lowest dynamic balance score for all SEBT directions (SY: $87.24{\pm}2.05cm$, IY: $83.20{\pm}1.30cm$, SO: $77.23{\pm}2.07cm$; p<.05) and there was no relationship between the dorsiflexion range of motion and dynamic balance in any group. Conclusion: Our findings suggest that ankle DFROM is not a crucial factor for dynamic stability regardless of aging and ankle instability. Other factors such as muscle strength or movement coordination should be considered for training dynamic balance. Therefore, we need to establish the rehabilitation process by measuring and treating ROM, balance, and muscle strength when treating young adults with and without ankle instability as well as elderly people.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.5
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• pp.21-29
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• 2017

Cold joint caused by construction delay is vulnerable to shear stress and it allows more rapid chloride penetration and diffusion. In the paper, investigation of chloride diffusion coefficient is performed for 1-year cured concrete considering compressive and tensile loading level and cold joint. The results are compared with the previous results in 91-day cured concrete. In the 1-year cured concrete without loading, 10.7% and 10.5% of diffusion reduction are evaluated for those in 91-day cured concrete, respectively. The reduction ratios are almost similar however the result in cold joint concrete shows much higher values. The results in 1-year cured concrete under 30% and 60% of compressive loading show reduction of chloride diffusion by 10.9% and 5.8% compared with 91-day cured results, which is caused by steady hydration of cement particles, so called, time effect. In the case of tensile loading, the differences in results are not significant regardless of time effect and cold joint since micro cracks which is weak point of concrete is much dominant despite of long term curing.

• Management & Information Systems Review
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• v.36 no.1
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• pp.181-213
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• 2017

According to the aging, the medical device industry is focused as a future promising industry. However, Korea medical device industry is not enough market competitiveness due to a narrow domestic market and a small company structure. This study aims at evaluating medical device priorities following 3 steps. First, we classify the medical device into three hierarchy categories and AHP survey was conducted on 30 experts in order to extract medical device priorities. Second, priority scores of medical device are analysed using AHP and Fuzzy-AHP. Third, a most important medical device is selected by comparing the volume of medical device manufacture and priority scores. As a result, 'dental implant' is the most import medical device, and we suggest a strategy based on a positioning map. The proposed methodology will provide a inspiration for establish of R&D and support policy in the medical device industry.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.59-70
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• 2016

This study aimed to find effective policies to cope with low birth rate in local authorities. It was analyzed the variables-a number of child-care facilities, paid parental leave, labor force participation, and total working hours-using panel analysis from 2005 to 2014. The results were as follows. First, after testing the whole years, we found that the fittest model was the fixed-effects model of 2 models(fixed-effects model, random effects model). A number of child-care facilities had positive effects, and a number of child-care facilities, and total working hours in women influenced negative effects on total fertility rate. Second, during the former time and the period of plan for low birth rate and aging society, a number of child-care facilities influenced negative effects on total fertility rate. Third, a number of child-care facilities had negative effects on total fertility rate in Busan, Daegu, and Kwangju. Paid parental leave influenced positively on total fertility rate in 5 cities and a province. Women's total working hours were a significant variable of total fertility rate in Jeju. This study found that the variables which influenced on total fertility rate were different by local authorities, and a number of child-care facilities and paid parental leave were very important variables on total fertility rate.

• Journal of the Korean association of regional geographers
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• v.22 no.3
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• pp.553-565
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• 2016

Population aging has been an increasing social issue and the elderly health has become one of the most urgent public attentions in Korea. The aims of this paper are to compare the subjective health status according to the personal characteristics, social networks, and daily leisure activities of the urban-rural elderly, and to analyze the influencing factors of their subjective health status. Using 2011 elderly survey data, ordered logit Model was established to extract influencing factors of the elderly health status. The results show that socioeconomic and demographic characteristics of individual as well as frequent social contacts and daily activities within neighborhood environments influence the level of health status of the elderly. The most significant factors affecting the elderly health are personal economic conditions such as the education achievement level and household income. The elderly who visit an elderly welfare center in Seoul has almost 1.82 times higher odds of increasing health status level than not to visit an elderly welfare center. This study may give some important policy implications of the elderly health promotion strategy in urban-rural communities.

• Journal of Nutrition and Health
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• v.48 no.4
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• pp.371-379
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• 2015

Purpose: This study was conducted to evaluate the factors influencing inadequate energy intake among Korean elderly. Methods: Our study included 1,869 elderly people (over 60 years old) who completed a dietary survey from the fifth Korean NHANES (2010). Factors that could affect the nutritional status of the elderly included age, family status, socio-economic factors (education, family income, livelihood security, employment), and health related factors (having chronic disease, functional status, diet therapy, depression, and suicidal thoughts). Energy and protein intake were assessed using the dietary intake data from 24hr recall method. Results: The percentage of people who consumed energy less than 75% of EEA for Koreans was 23.7% in men, 31.1% in women. The carbohydrate contribution to the total energy intake in the inadequate energy intake group was significantly higher than that in the adequate intake group (p < 0.05). Factors significantly related to inadequate energy intake after adjusting for age, family status, education, family income, employment, functional status, and suicidal thoughts were education (OR: 1.480 in men, 1.614 in women) and employment (OR: 1.751 in men, 1.464 in women), age 70 years or older in men (OR: 1.475), and living with family but without spouse in women (OR: 1.496). Conclusion: In summary, the results imply that energy intake of elderly would be affected by the status of social environment with aging and nutrition-related policy for Korean elderly should be based on the social status as well as health related conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.662-669
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• 2015

There has been an increased interest in the mitigation of wax deposition because wax, which usually accumulates in subsea oil-production systems, interrupts stable oil production and significantly increases the cost. To guarantee a required oil flow by mitigating wax deposition, we need to obtain a reliable estimation of the wax deposition. In this research, we perform simulations to understand the major mechanisms that lead to wax deposition, namely molecular diffusion, shear stripping reduction, and aging. While the model variables (shear reduction multiplier, wax porosity, wax thermal conductivity, and molecular diffusion multiplier) can be measured experimentally, they have high uncertainty. We perform an analysis of these variables and the amount of water and gas in the multiphase flow to determine these effects on the behavior of wax deposition. Based on the results obtained during this study for a higher wax porosity and molecular diffusion multiplier, we were able to confirm the presence of thicker wax deposits. As the shear reduction multiplier decreased, the thickness of the wax deposits increased. As the amount of water increased, there was also an increase in the amount of wax deposits until 40% water cut and decreased. As the amount of gas increased, the amount of wax deposits increased because of the loss of the light hydrocarbon component in the liquid phase. The results of this study can be utilized to estimate the wax deposition behavior by comparing the experiment (or field) and simulation data.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.6
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• pp.53-69
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• 2016

The purpose of this study is to analyze the factors of Elderly Social Activity (Employment) Programs participatory intention of middle and old aged and to figure out the undertone of research results. To achieve this aims, we conducted a literature survey on Elderly Social Activity Programs and local informatization, and then designed a questionnaire including the demographic information and the five variables, i.e., satisfaction on local informatization, satisfaction on health condition, satisfaction on economic condition, satisfaction on human relationship, and participatory intention of Elderly Social Activity (Employment) Programs. The data were collected through online and offline survey targeted those aged over 50 and participated in information literacy program in Korea. A total of 333 valid data were analyzed using SPSS and AMOS statistical packages. The results can be summarized as follows: satisfaction on local informatization and satisfaction on health condition have a statistically significant effect on Elderly Social Activity (Employment) Programs participatory intention. In the comparative analysis of two groups between economic active group and economic inactive group, only health has a statistically significant effect on their participatory intention in economic active group, not only health but also local informatization has a statistically significant effect on the their participatory intention in economic inactive group. Therefore, local informatization is an essential prerequisite and local informatization should be improved for the middle aged and elderlies who have willingness to participate in Elderly Social Activity (Employment) Programs.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.104-111
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• 2016

Recently, the quantities of chemical material are increasing in chemical industries. At that time, release accident is increasing due to aging of equipment, mechanical failure, human error, etc. and industrial complexes found community properties in a specific area. For that matter, chemical release accident can lead to hight probability of large disaster. There is a need to analyze the boundaries optimal sensor placement calculated by selecting release scenarios through release condition and wether condition in a chemical process for release detection and response. This paper is to investigate chlorine release accident scenarios using COMSOL. Through accident scenarios, a numerical calculation is studied to determine optimized sensor placement with weight of detection probability, detection time and concentration. In addition, validity of sensor placement is improved by robustness analysis about unpredicted accident scenarios. Therefore, this verifies our studies can be effectively applicable on any process. As mention above, the result of this study can help to place mobile sensor, to track gas release based concentration data.