• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.157-167
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• 2017

Millions of People die every year from diseases caused by exposure to outdoor air pollution. Especially, one of the most severe types of air pollution is fine particulate matter (PM10, PM2.5). South Korea also has been suffered from severe PM. This paper analyzes regional risks induced by PM10 and PM2.5 that have affected domestic area of Korea during 2014~2016.3Q. We investigated daily maxima of PM10 and PM2.5 data observed on 284 stations in South Korea, and found extremely high outlier. We employed extreme value distributions to fit the PM10 and PM2.5 data, but a single distribution did not fit the data well. For theses reasons, we implemented extreme mixture models such as the generalized Pareto distribution(GPD) with the normal, the gamma, the Weibull and the log-normal, respectively. Next, we divided the whole area into 16 regions and analyzed characteristics of PM risks by developing the FN-curves. Finally, we estimated 1-month, 1-quater, half year, 1-year and 3-years period return levels, respectively. The severity rankings of PM10 and PM2.5 concentration turned out to be different from region to region. The capital area revealed the worst PM risk in all seasons. The reason for high PM risk even in the yellow dust free season (Jun. ~ Sep.) can be inferred from the concentration of factories in this area. Gwangju showed the highest return level of PM2.5, even if the return level of PM10 was relatively low. This phenomenon implies that we should investigate chemical mechanisms for making PM2.5 in the vicinity of Gwangju area. On the other hand, Gyeongbuk and Ulsan exposed relatively high PM10 risk and low PM2.5 risk. This indicates that the management policy of PM risk in the west side should be different from that in the east side. The results of this research may provide insights for managing regional risks induced by PM10 and PM2.5 in South Korea.

• Asian Journal of Atmospheric Environment
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• v.10 no.4
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• pp.217-225
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• 2016

The purpose of the study was to initially investigate the concentration patterns of $PM_1$, $PM_{2.5}$ and $PM_{10}$ in the Seoul subway lines, and then to figure out the PM behaviors of internal and external sources inside subway tunnels. The PMs were monitored by a light scattering real-time monitor during winter (Jan. 8-26 in 2015) and summer (July 2-Aug. 7 in 2015) in tunnel air, in passenger cabin air, and in the ambient air. The daily average $PM_{10}$, $PM_{2.5}$, and $PM_1$ concentrations on these object lines were $101.3{\pm}38.4$, $81.5{\pm}30.2$, and $59.7{\pm}19.9{\mu}g/m^3$, respectively. On an average, the PM concentration was about 1.2 times higher in winter than in summer and about 1.5 times higher in underground tunnel sections than in ground sections. In this study, we also calculated extensively the average PM mass ratios for $PM_{2.5}/PM_{10}$, $PM_1/PM_{10}$, and $PM_1/PM_{2.5}$; for example, the range of $PM_{2.5}/PM_{10}$ ratio in tunnel air was 0.82-0.86 in underground tunnel air, while that was 0.48-0.68 in outdoor ground air. The ratio was much higher in tunnel air than in outdoor air and was always higher in summer than in winter in case of outdoor air. It seemed from the results that the in/out air quality as well as a proper amount of subway ventilation must be significant influence factors in terms of fine PM management and control for the tunnel air quality improvement.

• Journal of the Korean Society of Visualization
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• v.20 no.1
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• pp.45-51
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• 2022

Airborne particulate matter(PM) has been a global environmental problem. PM whose diameter is smaller than 10 ㎛ can permeate respiratory organs and has harmful effects on human health. Therefore, PM monitoring systems are necessary for management of PM and prevention of PM-induced negative effects. Conventional PM monitoring techniques are expensive and cumbersome to handle. In the present study, two types of PM monitoring devices were designed for measuring indoor PM concentration, portably. We experimentally investigated the performance of three commercial PM concentration measurement sensors in a closed test chamber. As a result, PM2008 sensor showed the best PM concentration measurement accuracy. Linear regression method was applied to convert PM concentration value acquired from PM2008 sensor into ground truth value. A mobile application(app.) was also created for users to check the PM concentration, easily. The mobile app. also provides safety alarm when the PM₁₀ concentration exceeds 81 ㎛/m³. The developed hand-held system enables the facile monitoring of surrounding air quality.

• Research in Community and Public Health Nursing
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• v.26 no.3
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• pp.303-311
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• 2015

Purpose: The purpose of this study was to survey patient activation for self-management and to identify factors associated with patient activation for self-management among community residents with osteoarthritis in Korea. Methods: Cross-sectional study design was used. Survey data were collected from 270 community residents with osteoarthritis through direct interviews. Studied factors included patient activation, joint pain, physical function, depression, and general characteristics. Data were analyzed using chi-squared test, t-test and multivariate logistic regression analysis. Results: The participants' mean score of patient activation was $56.0{\pm}16.61$. The mean score of each factor was $10.6{\pm}5.89$ for joint pain, $5.5{\pm}3.56$ for physical function, and $19.3{\pm}10.01$ for depression. The patient activation level was significantly associated with depression and general characteristics such as education, religion, comorbid hypertension, and use of medical clinics (p<.05). Conclusion: The findings suggest that depression, education, religion, comorbid hypertension, and use of medical clinics may be important factors to be considered when developing programs of patient activation for self-management. This is the first study that measured patient activation, and further studies are suggested to find factors associated with patient activation for self-management among community residents with other chronic diseases.

• Journal of Environmental Science International
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• v.31 no.1
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• pp.9-21
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• 2022

Today's cities require deeper understanding of the thermal environment and PM₁₀ as their management becomes more critical. Based on these circumstances, this study investigated the Granger causality between the thermal environment and PM₁₀ of the 25 districts of Seoul, the most populous and urbanized city in Korea. The results of the Granger causality test on the thermal environment and PM₁₀ were classified into 12 types. Except for type 12, the temperature and urban island heat intensity of the other 11 types operated as a Granger-cause to each other in both directions. Temperature operates as a Granger-cause of urban island heat intensity in type 12. The PM₁₀ level and urban pollution island intensity operated as a Granger-cause to each other in all districts. For types 1 and 2, thermal environment operated as a Granger-cause to PM₁₀ in one direction, and type 3-type 12 confirmed that thermal environment and PM₁₀ operated as a Granger-cause in both directions. Findings reveal the intricate causalities between thermal environment and PM₁₀ at the district level and suggest mitigation strategies that are more location based.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.133-142
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• 2011

Overhead facility design problem(OFDP) is one of the shortest rectilinear flow network problem(SRFNP)[4]. Genetic algorithm(GA), artificial immune system(AIS), population management genetic algorithm (PM) and greedy randomized adaptive search procedures (GRASP) were introduced to solve OFDP. A path matrix formed individual was designed to represent rectilinear path between each facility. An exchange crossover operator and an exchange mutation operator were introduced for OFDP. Computer programs for each algorithm were constructed to evaluate the performance of algorithms. Computation experiments were performed on the quality of solution and calculations time by using randomly generated test problems. The average object value of PM was the best of among four algorithms. The quality of solutions of AIS for the big sized problem were better than those of GA and GRASP. The solution quality of GRASP was the worst among four algorithms. Experimental results showed that the calculations time of GRASP was faster than any other algorithm. GA and PM had shown similar performance on calculation time and the calculation time of AIS was the worst.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.123-132
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• 2004

The purpose of this study was to characterize background mass concentration of PM$_{10}$ and metallic composition from September 2001 to August 2002 in comparison with Asan and Seoul. Annual mean of PM$_{10}$ concentrations in Asan and Seoul were 47.98 and 75.33$\mu\textrm{g}$/㎥, respectively. The concentrations of PM$_{10}$ were highest in spring season in both cities. The concentrations of measured metals except for As and Pb in Asan were higher than those in Seoul. Yellow dust could affect the mass and metals concentrations of measured PM$_{10}$ in Asan and Seoul. Relationship between measured metals concentrations showed that Si and Fe were associated with natural sources such as soil. Pb, Cu and Zn were closely related to urban anthropogenic sources such as fuel combustion. Especially, relationship between metals showed different association during yellow dust. Proper management for PM$_{10}$ will need in Asan, considered the concentrations of metallic elements in PM$_{10}$ in Asan were relatively higher than those in Seoul.se in Seoul.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.209-223
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• 2018

We investigated tree composition, stand characteristics, biomass allocation pattern and carbon storage variability in Sal forests (Shorea robusta Garten.) under two forest management regimes (Sal forest and Sal plantation) in Tripura, Northeast India. The results revealed higher species richness (29 species), stand density of $1060.00{\pm}11.12stems\;ha^{-1}$ and diversity index ($1.90{\pm}0.08$) in Sal forest. and lower species richness (4 species), stand density of $ 230.00{\pm}37.22stems\;ha^{-1}$ and diversity index ($0.38{\pm}0.15$) in Sal plantation. The total basal cover $33.02{\pm}4.87m^2ha^{-1}$) and dominance ($0.76{\pm}0.08$) were found higher in Sal plantation than the Sal forest ($22.53{\pm}0.38m^2ha^{-1}$ and $0.23{\pm}0.02$ respectively). The total vegetation carbon density was recorded higher in Sal plantation ($219.68{\pm}19.65Mg\;ha^{-1}$) than the Sal forest ($167.64{\pm}16.73Mg\;ha^{-1}$). The carbon density estimates acquired in this study suggest that Sal plantation in Tripura has the potentiality to store a large amount of atmospheric carbon inspite of a very low species diversity. However, Sal forests has also an impending sink of carbon due to presence of large number of young trees.

• Korean journal of food and cookery science
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• v.30 no.4
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• pp.412-418
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• 2014

This study considered the selection attributes of bakery consumers and schematized characteristic attributes of being selected by customers by image through a correspondence analysis in terms of own preferring bakery. Self-administrated questionnaires were completed by consumers (452 samples), and the data were analysed by frequency, chi-square, one-way ANOVA, reliability analysis and correspondence analysis. According to the survey results regarding the mean value on bakery selection attributes, it was shown to be in the order of taste ($4.73{\pm}0.70$), sanitation ($4.70{\pm}0.68$), service ($4.21{\pm}0.84$), price ($4.03{\pm}0.92$), consideration ($4.01{\pm}0.96$), communication ($4.01{\pm}0.96$), health ($3.99{\pm}0.98$), and location ($3.83{\pm}0.99$). In the analysis of difference with regard to the selection attributes according to the preferred bakery, both consideration ($4.05{\pm}0.90$) and communication ($3.98{\pm}0.93$) showed a high value in individual bakery, thereby presenting a significant difference (p<0.05). As a result of having carried out correspondence analysis in order to prepare an image map according to the preferred bakery, the selection attributes of employees' service and communication showed the closest image map to individual bakery. Location and sanitation were very close to franchise bakery. Further, other bakery shops were schematized in a relatively close distance to price.

• Korean Journal of Occupational Health Nursing
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• v.25 no.4
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• pp.384-393
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• 2016

Purpose: The purpose of this study was to examine the effectiveness of Participatory Action-Oriented Training (PAOT) programs in korean manufacture workers with metabolic syndrome for three years. Methods: A total of 890 workers with risks of metabolic syndrome were recruited from one workplace. The experimental group (n=51) received PAOT program for the preventive management on metabolic syndrome, while the control group (n=51) received conventional program. Results: In the experimental group who participated in PAOT program, percentage of achieved action plans was 73.4% at three months, 75.8% at six months, 82.8% at three years. After three years, the rate of risk factor in the experimental group has significantly decreased from $1.94{\pm}1.77$ to $0.76{\pm}1.25$ for moderate exercise, and from $1.72{\pm}2.01$ to $1.04{\pm}1.59$ for the strenuous exercise. Systolic and diastolic blood pressure has significantly decreased from $125.06{\pm}11.83$ to $117.65{\pm}19.94$, from $83.45{\pm}13.38$ to $76.39{\pm}8.09$ mmHg. In addition, risk factor score also decreased from $3.31{\pm}0.61$ to $1.41{\pm}0.89$. Conclusion: To improve the effectiveness of PAOT program for the management of risk factors of metabolic syndrome, there is a need to continue implement programs and analyze the long-term effects are required in the workplace.