• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.579-593
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• 2009

Several fine particle-related policies in Northeast United States were investigated in support of the execution of special measures to improve air quality of Seoul Metropolitan Area (SMA). The definition of particulate matter (PM) in the Clean Air Act (CAA), components and procedures of Regional Haze Rule (RHR), and Air Quality Management (AQM) were reviewed. Several State Implementation Plans (SIPs) were also reviewed as the way to attain required air quality under the Clean Air Act. $PM_{2.5}$ attainment SIP of Maryland, 8-hr Ozone attainment SIP of New Jersey, and Regional Haze Rule attainment SIP of MANE-VU were analyzed in detail as case studies. We realized that "Special Measures for Air Quality Improvement in the Seoul Metropolitan Area" has many similarities with its US counterparts in terms of purpose, components, procedures, and implementation methods. US policies, however, have more advanced features, such as standardized procedures and methods, transparent guidelines, and stable relationship among federal/state/local governments and stakeholders, which would be helpful to improve air quality in SMA.

• Journal of Periodontal and Implant Science
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• v.47 no.1
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• pp.20-29
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• 2017

Purpose: The microstructural characteristics of trabecular bone were identified using micro-computed tomography (micro-CT), in order to develop a potential strategy for implant surface improvement to facilitate osseointegration. Methods: Alveolar bone specimens from the cadavers of 30 humans were scanned by high-resolution micro-CT and reconstructed. Volumes of interest chosen within the jaw were classified according to Hounsfield units into 4 bone quality categories. Several structural parameters were measured and statistically analyzed. Results: Alveolar bone specimens with D1 bone quality had significantly higher values for all structural parameters than the other bone quality categories, except for trabecular thickness (Tb.Th). The percentage of bone volume, trabecular separation (Tb.Sp), and trabecular number (Tb.N) varied significantly among bone quality categories. Tb.Sp varied markedly across the bone quality categories (D1: $0.59{\pm}0.22mm$, D4: $1.20{\pm}0.48mm$), whereas Tb.Th had similar values (D1: $0.30{\pm}0.08mm$, D4: $0.22{\pm}0.05mm$). Conclusions: Bone quality depended on Tb.Sp and number-that is, endosteal space architecture-rather than bone surface and Tb.Th. Regardless of bone quality, Tb.Th showed little variation. These factors should be taken into account when developing individualized implant surface topographies.

• The Journal of Advanced Prosthodontics
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• v.5 no.1
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• pp.29-35
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• 2013

PURPOSE. To longitudinally assess the quality of life in maxillectomy patients rehabilitated with obturator prosthesis. MATERIALS AND METHODS. Thirty-six subjects were enrolled in the span of 16 months, out of which six were dropouts. Subjects (age group 20-60 years) with maxillary defects, irrespective of the cause, planned for definite obturator prosthesis, were recruited. The Hindi version of European Organization for Research and Treatment of Cancer, Head and Neck version 1 of Quality of Life Questionnaire was used before surgical intervention and one month after definitive obturator. Questionnaire includes 35 questions related to the patient's physical health, well being, psychological status, social relation and environmental conditions. The data were processed with statistical package for social science (SPSS). Probability level of P<.05 was considered statistically significant. RESULTS. The quality of life after rehabilitation with obturator prosthesis was 81.48% (${\pm}13.64$) on average. On item-level, maximum mean scores were obtained for items problem with teeth ($1.87{\pm}0.94$), pain in mouth ($1.80{\pm}0.92$), trouble in eating ($1.70{\pm}0.88$), trouble in talking to other people ($1.60{\pm}1.22$), problems in swallowing solid food ($1.57{\pm}1.22$) and bothering appearance ($1.53{\pm}1.04$); while minimum scores were obtained for the items coughing ($1.17{\pm}0.38$), hoarseness of voice ($1.17{\pm}0.53$), painful throat ($1.13{\pm}0.43$), trouble in having social contacts with friends ($1.10{\pm}0.40$) and trouble having physical contacts with family or friends ($1.10{\pm}0.31$). CONCLUSION. Obturator prosthesis is a highly positive and non-invasive approach to improve the quality of life of patients with maxillectomy defects.

• Particle and aerosol research
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• v.15 no.3
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• pp.91-104
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• 2019

In this study, hourly measurements of $PM_{2.5}$ and its major chemical constituents such as organic and elemental carbon (OC and EC), and ionic species were made between January 15 and February 10, 2018 at the air pollution intensive monitering station in Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were collected at the same site and analyzed for OC, EC, water-soluble OC (WSOC), humic-like substance (HULIS), and ionic species. Over the whole study period, the organic aerosols (=$1.6{\times}OC$) and $NO_3{^-}$ concentrations contributed 26.6% and 21.0% to $PM_{2.5}$, respectively. OC and EC concentrations were mainly attributed to traffic emissions with some contribution from biomass burning emissions. Moreover, strong correlations of OC with WSOC, HULIS, and $NO_3{^-}$ suggest that some of the organic aerosols were likely formed through atmospheric oxidation processes of hydrocarbon compounds from traffic emissions. For the period between January 18 and 22 when $PM_{2.5}$ pollution episode occurred, concentrations of three secondary ionic species ($=SO{_4}^{2-}+NO_3{^-}+NH_4{^+}$) and organic matter contributed on average 50.8 and 20.1% of $PM_{2.5}$, respectively, with the highest contribution from $NO_3{^-}$. Synoptic charts, air mass backward trajectories, and local meteorological conditions supported that high $PM_{2.5}$ pollution was resulted from long-range transport of haze particles lingering over northeastern China, accumulation of local emissions, and local production of secondary aerosols. During the $PM_{2.5}$ pollution episode, enhanced $SO{_4}^{2-}$ was more due to the long-range transport of aerosol particles from China rather than local secondary production from $SO_2$. Increasing rate in $NO_3{^-}$ was substantially greater than $NO_2$ and $SO{_4}^{2-}$ increasing rates, suggesting that the increased concentration of $NO_3{^-}$ during the pollution episode was attributed to enhanced formation of local $NO_3{^-}$ through heterogenous reactions of $NO_2$, rather than impact by long-range transportation from China.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.3
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• pp.233-244
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• 2014

The objective of this study was to explore the characteristics of concentration of indoor air pollutants, such as $PM_{10}$, $CO_2$, and $NO_2$, measured by tele-monitoring system in a Seoul Metropolitan underground railway station from January 1, 2008 to December 31, 2012. The annual average concentration of indoor air pollutants actually varied over a wide range and was found to exhibit marked variation with time and measurement sites (tunnel inlet, platform, and concourse). After installing platform screen doors, the average $PM_{10}$ concentration on platform and concourse was decreased by 43.8% and 31.2%, respectively during the study periods. The relationship between the concentration of $PM_{10}$ and meteorological parameters (relative humidity and rainfall) or the Asian dust events was regarded as statistically significant. The correlations between the number of boarding/alighting passengers and $PM_{10}$, $CO_2$, and $NO_2$ were calculated. A p-value of less than 0.01 was regarded as significant except $NO_2$. The I/O ratio of $PM_{10}$ concentration was elevated after a congested time (about 08:00 am). The average I/O ratios of $NO_2$ were observed in concourse and platform on 03:00 am with $1.76{\pm}0.91$ and $1.50{\pm}0.51$, respectively. The average daily variation of standard excess rate of $PM_{10}$ and $NO_2$ concentration in concourse and platform was investigated. The highest standard excess rate was observed on 21:00 (09:00 pm).

• The Korean Journal of Rehabilitation Nursing
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• v.4 no.2
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• pp.219-231
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• 2001

The purpose of this study was to investigate the relationship among percieved social support, hope and quality of life of the cancer patients and to gain the baseline data for development of nursing intervention program for promoting quality of life in cancer patients. The design of this study was a cross sectional correlational survey. The subjects were 220 out and in-cancer patients in 5 general hospitals in Pusan. The data were collected from July 2 to August 1, 2001. The instruments were the Percieved social support scale(16 items, 5 point scale) had developed by Tae(1986), Hope scale(12 items, 4point scale) developed by Nowotny(1989) and Quality of life scale(31 items, 10 point scale) developed by Tae et al.(2000). The data was analyzed by the SPSS/PC+ program using frequency & percentage, item mean & standard deviation, t-test, ANOVA & Scheffe test, Pearson's correlation coefficient. The results of this study was as follows: 1) The item mean score of quality of life was $6.05{\pm}1.16$ (range 0-10). The highest score of subarea of the quality of life was the spiritual wellbeing area ($7.09{\pm}1.63$) and the lowest score was social wellbeing area ($5.53{\pm}1.65$). The mean score of perceived social support was $52.65{\pm}10.32$ (최저 1, 최고 80). The mean score of family support was $32.71{\pm}6.66$ (range 1-40) and the mean score of medical team support was $19.93{\pm}5.95$ (range 1-40). The mean score of Hope was $37.02{\pm}5.64$ (range 1-48). 2) There were statistically significant difference in the score of quality of life according to the life effect of religion(F=3.97, p=0.00), treatment method(F=2.94, p=0.01), area of diagnosis(F= 3.48, p=0.01), stage of disease (F=13.74, p=0.00). 3) There was significant correlation between perceived social support(r=0.44, p=0.000 ; family support ; r=0.334, p=0.000, medical support; r=0.395, p=0.000), hope(r=0.563, p=0.000) and quality of life. In conclusion, there was a significant relationship among perceived social support, hope and quality of life. Therefore perceived social support, hope intervention programs should be developed to improve the quality of life in cancer patients.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.1-15
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• 2018

Nation-wide systematic and comprehensive measurements of air quality criteria species have been made over 340 sites currently in Korea since 1990. Using these data, temporal and spatial trends of $SO_2$, $PM_{10}$, $NO_2$, $O_3$, CO and $O_x(NO_2+O_3)$ were analyzed to characterize and evaluate implementing efficiency of air quality policy and regulations. Due to strict and effective policy to use cleaner fuels in late 1980s and 1990s, the primary pollutants, such as $SO_2$, CO, and $PM_{10}$ decreased sharply by early 2000s in all parts of Korea. After this period, their concentrations declined with much lower rates in most parts of Korea. In addition, isolated but noticeable numbers of places, especially in major ports, newly developing towns and industrial parks, sustained high levels or even showed further degradation. Despite series of emission control strategies were enforced since early 1990s, $NO_2$ concentrations haven't changed much till 2005, due to significant increase in number of automobiles. Nevertheless, we confirmed that the staggering levels of $NO_2$ and $PM_{10}$ improved evidently after 2005, especially in Seoul Metropolitan Area (SMA), where enhanced regulations for $NO_2$ and $PM_{10}$ emissions was imposed to automobiles and large emission sources. However, their decreasing trends were much lessened in recent years again as current air quality improvement strategies has been challenged to revise further. In contrast to these primary species, annual $O_3$, which is secondary product from $NO_2$ and volatile organic compounds (VOCs), has increased consistently with about 0.6 ppbv per year in every urban part of Korea, while yearly average of daily maximum 8-hour $O_3$ in summer season had a much higher rate of 1.2 ppbv per year. Increase of $O_3$ can be explained mainly by reductions of NO emission. Rising background $O_3$ in the Northeast Asia and increasing oxidizing capacity by changing photochemistry were likely causes of observed $O_3$ increase. The future air quality policy should consider more effective ways to lower alarming level of $O_3$ and $PM_{10}$.

• Journal of Environmental Science International
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• v.29 no.2
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• pp.191-200
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• 2020

This study provides a basis for research to establishing air quality standards in Gyeongnam. The trends and deviations in air quality concentrations and short-term environmental standards were analyzed. Furthermore, the regional standards and World Health Organization's (WHO) air quality guidelines (AQGs) were taken into account. The annual average PM₁₀ standard for cities anc counties ate 40 ㎍/㎥ and 30 ㎍/㎥, respectively. SO₂ and NO₂ are achieving national standards and need to be strengthened to the minimum regional standard and WHO AQGs. The PM_2.5 standard, which has not reached national standards, needs to be set at the level of national standards, and is also the target level for 2024 of the Gyeongsangnam and national PM_2.5 management plans.

• Environmental Engineering Research
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• v.23 no.2
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• pp.143-149
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• 2018

Air quality conditions and pollution status have been evaluated in the industrial area between Sharjah and Ajman border in UAE. Daily concentrations of $O_3$, CO, $NO_2$, $SO_2$, $PM_{2.5}$, $PM_{10}$, Total Volatile Organic Compounds (TVOC) and Total Suspended Particulate (TSP) have been monitored from Sept. 2015 to April 2016. The monthly average concentrations of $O_3$, CO, $NO_2$, $SO_2$, TVOC were within the UAE ambient air quality standards during the survey period. However, $PM_{10}$ and TSP levels exceeded the recommended limits in Sept. 2015, Oct. 2015 and March 2016. Temporal variations in air quality parameters showed highest levels in March 2016 for $PM_{2.5}$, $PM_{10}$, $NO_2$, TVOC and TSP, whereas $O_3$, $SO_2$ and CO showed relatively low values in this month. $PM_{2.5}$ levels in ambient air were above the EPA guideline of $35{\mu}g/m^3$ in all months. $PM_{2.5}$ was the critical ambient air pollutant with Index for Pollutant ($I_p$) values varying from 103-209, indicating Air Quality Index categories of unhealthy for sensitive groups (62.5%) to unhealthy (25%) to very unhealthy (12.5%). The $I_p$ average values of $PM_{2.5}$ decreased from Sept. 2015 to reach lowest value in Dec. 2015 before increasing gradually, peaking in March 2016. These results suggest the potential health risks associated with $PM_{2.5}$ is low in winter, where the prevailing meteorological conditions of lower temperatures, higher humidity, higher wind speed reduced particulate matter. The results revealed the industrial area is impacted by anthropogenic and natural sources of particulate matter.

• Asian Journal of Atmospheric Environment
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• v.12 no.2
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• pp.139-152
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• 2018

The urban model inter-comparison study (UMICS) was conducted in order to improve the performance of air quality models (AQMs) for simulating fine particulate matter ($PM_{2.5}$) in the Greater Tokyo Area of Japan. UMICS consists of three phases: the first phase focusing on elemental carbon (UMICS1), the second phase focusing on sulfate, nitrate and ammonium (UMICS2), and the third phase focusing on organic aerosol (OA) (UMICS 3). In UMICS2/3, all the participating AQMs were the Community Multiscale Air Quality modeling system (CMAQ) with different configurations, and they similarly overestimated $PM_{2.5}$ nitrate concentration and underestimated $PM_{2.5}$ OA concentration. Various sensitivity analyses on CMAQ configurations, emissions and boundary concentrations, and meteorological fields were conducted in order to seek pathways for improvement of $PM_{2.5}$ simulation. The sensitivity analyses revealed that $PM_{2.5}$ nitrate concentration was highly sensitive to emissions of ammonia ($NH_3$) and dry deposition of nitric acid ($HNO_3$) and $NH_3$, and $PM_{2.5}$ OA concentration was highly sensitive to emissions of condensable organic compounds (COC). It was found that $PM_{2.5}$ simulation was substantially improved by using modified monthly profile of $NH_3$ emissions, larger dry deposition velocities of $HNO_3$ and $NH_3$, and additionally estimated COC emissions. Moreover, variability in $PM_{2.5}$ simulation was estimated from the results of all the sensitivity analyses. The variabilities on CMAQ configurations, chemical inputs (emissions and boundary concentrations), and meteorological fields were 6.1-6.5, 9.7-10.9, and 10.3-12.3%, respectively.