• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.651-656
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• 2006

Wu and Clements-Croome (2005) investigate the optimization problem of PM policies for situations where the quality of PM is a random variable with a certain probability distribution. However, they assume that the cost of preventive maintenance is constant, not depending on the quality of PM. Thus, this paper considers a periodic PM model when PM cost depends on the quality of PM activity. The optimal PM policy are presented for the extended PM model and the numerical examples are presented for illustrative purpose.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1277-1280
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• 2012

Aim: Studies have shown effects of surgery, radiation and chemotherapy on quality of life in cases of gynaecological cancer. Very few studies are available examining the quality of life of individuals in Turkey who have been diagnosed with gynaecological cancer and undergoing treatment. Method: This study was performed to evaluate the quality of life of such patients using the EORTC-QLQ-C30 Quality of Life Index. Chi-square Yates, Mann-Whitney-U tests and variance analysis used for statistical analizing. Results: The EORTC-QLQ-C30 Quality of Life Index mean points for "general well-being and quality of life" of the patients were found to be $60.5{\pm}25.0$. In the sub-groups of the Quality of Life Index determined fatigue ($60.1{\pm}24.8$), economic difficulties ($46.9{\pm}33.3$), pain and loss of appetite ($42.9{\pm}27.8$; $42.9{\pm}34.0$) and insomnia ($40.1{\pm}34.0$) were the symptoms most reported to have a negative effect on quality of life. Statistical significance was noted for marital status and income status (p<0.05) but not educational level. Conclusion:Determination of quality of life of women with a diagnosis of gynaecological oncological disease who are undergoing chemotherapy enables provision of a more comprehensive and higher quality of care.

• 한국대기환경학회지
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• 제33권6호
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• pp.616-625
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• 2017

Measurements using five real-time particle samplers were compared to measurements using three NRM (National Reference Method system) filter-based samplers(Gravimetric method) at Incheon, Korea, between May and August, 2014. The purpose of this study was to suggest the quality assurance/quality control (QA/QC) method of each instrument for use in a real-time continuous particle sampler to measure the mass of airborne particles with an aerodynamic diameter less than $2.5{\mu}m$ ($PM_{2.5}$). Five real-time particle samplers of BAM1020, FH62C_14, TEOM, PM-711 and SPM-613 were evaluated by comparing its measured 23 hr average $PM_{2.5}$ concentrations with those measured with NRM filter-based samplers simultaneously. The parameters(e.g. Inlet heating condition, Slope factor, Film response, Intercept, Background, Span value) of the real-time samplers were optimized respectively by conducting test performance evaluation during 7 days in field sampling. For example, inlet heating temperature of TEOM sampler controls $35{\sim}40^{\circ}C$ to minimize the fluctuation of the real-time measurement data and background value of BAM1020 is the key factor affecting the accuracy of $PM_{2.5}$ mass concentration. We classified the $PM_{2.5}$ concentration according to relative humidity (80%) to identify water absorbed in aerosols by measuring the ${\beta}$-ray samplers(BAM1020, FH62C_14) and TEOM. ${\beta}$-ray samplers were not strongly affected by relative humidity that the difference of the average $PM_{2.5}$ concentration was about 5%. On the other hand, The TEOM sampler overestimated $PM_{2.5}$ mass concentration about 15% at low relative humidity (<80%).

• 환경영향평가
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• 제27권2호
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• pp.215-231
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• 2018

본 연구에서는 지상 기상 및 $PM_{2.5}$ 농도, GOCI 위성의 AOD 등 다양한 관측 자료와 WRF-CMAQ 모델링을 통해 2016년과 2017년의 우리나라 가을철 $PM_{2.5}$ 농도변화 원인을 분석하였다. 지상에서 관측된 2017년 전국 평균 $PM_{2.5}$ 농도는 2016년에 비해 약 12.3% ($3.0{\mu}g/m^3$) 감소한 것으로 나타났다. 두 해간 $PM_{2.5}$ 농도 차이는 10월과 11월의 두 사례(사례1: 10월 11일~10월 20일, 사례2: 11월 15일~19일) 기간에 주로 발생하였으며, 2017년의 기상조건이 2016년에 비하여 국외로부터 대기오염물질의 장거리 수송이 어렵고, 국내의 대기환기 효과를 증가시키는 방향으로 변화한 것이 주요한 원인으로 분석되었다. WRF-CMAQ 모델링 시스템을 이용하여 기상조건 변화가 $PM_{2.5}$ 농도에 미치는 정량적인 영향을 평가한 결과, $PM_{2.5}$ 모의농도는 2016년 대비 2017년의 사례1 기간에는 64.0% ($23.1{\mu}g/m^3$) 감소, 사례2 기간에는 35.7% ($12.2{\mu}g/m^3$) 감소한 것으로 나타나, 관측 농도 기반 감소율인 53.6% (사례1)와 47.8% (사례2)에 상응하는 감소율을 보였다. 따라서 기상조건 변화가 우리나라 가을철 $PM_{2.5}$ 농도 변화에 큰 영향을 미치는 것으로 분석되었다. 기상조건 변화로 인한 우리나라 $PM_{2.5}$ 농도 감소에 미친 국내외 기여율은 사례1 기간에 국외로부터의 장거리 수송영향이 52.8% 그리고 대기환기 효과에 따른 국내영향이 47.2% 로 국내외 영향이 유사하게 나타나지만, 사례2 기간에는 국외영향이 66.4% 그리고 국내영향이 33.6%로서 국외영향의 감소효과가 더 크게 나타났다.

• Journal of the Korean Data and Information Science Society
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• 제18권3호
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• pp.689-696
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• 2007

This paper considers a Bayesian approach to determine an optimal PM policy with random maintenance quality. Thus, we assume that the quality of a PM action is a random variable following a probability distribution. When the failure time is Weibull distribution with uncertain parameters, a Bayesian approach is established to formally express and update the uncertain parameters for determining an optimal PM policy. Finally, the numerical examples are presented for illustrative purpose.

• 한국대기환경학회지
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• 제28권3호
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• pp.282-293
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• 2012

This study aimed to show the chemical characteristics of $PM_{10}$ and $PM_{2.5}$ during Asian dust (AD) events and high PM episodes observed in Seoul. Time-resolved chemical composition of $PM_{10}$ or $PM_{2.5}$ was monitored in 1 hour interval using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF spectrometer at Seoul intensive monitoring site in 2009. Considering that AD events were classified into three different cases according to the source area and pathway, the concentrations of ammonium-sulfate and trace metal components were relatively high when the AD were occurred in Gobi and inner-mongolia and transported across the Bohai bay. In addition, the influence of alkaline dust, which carried from saline land located in the northeastern China, was observed when the AD was originated from Gobi, inner-mongolia, and Manchuria. Except AD events, the high PM episodes observed in Seoul were impacted by various anthropogenic sources such as biomass burning, motor vehicle, oil combustion and road dust.

• 한국습지학회지
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• 제6권1호
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• pp.133-147
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• 2004

전북 군산 및 부안 지역을 중심으로 이루어지는 새만금간척공사 수역과 그 주변 해역의 수질 및 저질 분포 특성을 구명하기 위하여 2001년 9월에 총 101개 퇴적물 시료와 69개의 해수 시료를 채취, 분석하였다. 주요 수질 항목별 평균 및 표준편차는 수온 $25.51{\pm}0.68^{\circ}C$, 염분 $29.88{\pm}5.01psu$, COD $1.40{\pm}0.78mg/L$, 용존무기질소 (DIN) $0.352{\pm}0.417mg/L$, 그리고 인산인 $0.027{\pm}0.023mg/L$ 이었다. 영양염류 및 COD는 동진강 및 만경강 하구에서 매우 높은 농도를 보였으며, 곰소만과 새만금 입구 수역은 매우 낮은 값을 보였다. COD, 영양염류 농도 및 N/P 등은 염분과 유의적 역상관관계를 보였으며, 이는 대부분의 오염 물질이 육상 기원임을 시사하였다. 주성분 분석에 의한 수질 분포 역시 새만금 수역으로 유입되는 지류에서 높은 영양염류 및 유기물 농도를 보여 타 수역에 비하여 수질오염도가 높았다. 퇴적물의 경우 주요 중금속류 및 일반저질항목별 농도는 알루미늄 $2.28{\pm}0.92%$, 카드뮴 $0.61{\pm}0.27ppm$, 구리 $8.95{\pm}4.06ppm$, 철 $1.19{\pm}0.37%$, 망간 $182.31{\pm}77.45ppm$, 니켈 $10.83{\pm}4.97ppm$, 납 $15.20{\pm}4.35ppm$, 아연 $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, 강열감량 $1.29{\pm}1.08%$, 함수율 $24.11{\pm}4.49%$, 총질소 $0.02{\pm}0.02%$ 그리고 총탄소 $0.22{\pm}0.30%$ 이었다. 저질의 공간 분포 특성은 수질처럼 명확하지는 않았으나, 금강하구 수역에서 전반적으로 높은 농도를 보였다. 저질 항목별 상관관계는 중금속과 유기물함량 간에 유의적 관계가 있었으며 (p<0.05), 퇴적물내의 농축비 (enrichment factor)가 대부분 수역에서 1-2의 범위를 보여 중금속의 외부 유입이 심각하지 않은 것으로 밝혀졌다. 또한 퇴적물 내의 중금속 농도 역시 일반적인 해양 퇴적물에서 검출되는 범위 이내로 새만금 및 주변 수역의 저질 상태는 매우 양호한 것으로 판단된다.

• 한국대기환경학회지
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• 제34권3호
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• pp.373-392
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• 2018

The emission of air pollutants in China has increased rapidly as its economy expanded over the last decades. The Chinese government has recently acknowledged the seriousness of the resulting air pollution and is trying to improve air quality in many ways. Here, we review the air quality control and management policies in China, one of our closest neighbors, because these policies may also influence the air quality in Korea. This study examined the recent policies on $PM_{2.5}$ reduction and analyzed the variation in air quality and air pollutant emissions in China. The ambient air quality and emission standards in China have been strengthened, based on China's Air Pollution Prevention and Control Action Plan of 2013. As a result, the annual mean concentration of $PM_{2.5}$ in 2015 in 74 large Chinese cities declined by 23.6% compared with 2013 values. Coal consumption in China also has been reduced by more than 10% per year since 2013. Furthermore, the laws controlling atmospheric emissions were revised again in 2016, and an air pollution forecasting and warning system was implemented to help manage air pollution problems. At present, the Chinese government is trying to evaluate its policies on $PM_{2.5}$ and find a new paradigm to mitigate ongoing $PM_{2.5}$ pollution. In this context, a joint study between Korea and China has been initiated to investigate the characteristics and sources of ambient $PM_{2.5}$ and to identify factors contributing to the high $PM_{2.5}$ concentrations in northeast China. We expect that this academic collaboration will benefit both countries in their search for new policies for $PM_{2.5}$ reduction.

• ALGAE
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• 제20권2호
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• pp.133-140
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• 2005

Daily variation of phytoplankton community and environmental parameters were investigated at the lower Nakdong River (Mulgum) from January 2002 to December 2003 to investigate the dynamics of a phytoplankton community in detail. The daily results of water quality in this investigation showed pH (8.1 $\pm$ 0.7), DO (10.3 $\pm$ 2.7 $mg{\cdot}l^{-1}$), water temp. (18.8 $\pm$ 7.4°C), BOD (2.4 $\pm$ 1.0 $mg{\cdot}l^{-1}$), COD (5.3 $\pm$ 1.2 $mg{\cdot}l^{-1}$) and chl. a (43.5 $\pm$ 35.1 mg ${\cdot}m^{-3}$). The results of nutrient factors were the following: TN (3.1 $\pm$ 0.8 $mg{\cdot}l^{-1}$), NO3-N (2.5 $\pm$ 0.5 $mg{\cdot}l^{-1}$), TP (90 $\pm$ 48 ${\mu}g\;{\cdot}\;l^{-1}$), PO4-P (43 $\pm$ 30 ${\mu}g\;{\cdot}\;l^{-1}$). Dominant phytoplankton species during the study period were diatom (Stephanodiscus hantzschii, Aulacoseira granulata var. angustissima and A. italica) and cyanobacteria (Microcystis aeruginosa, Aphanizomenon flos-aquae). The small centric diatom, Stephanodiscus hantzschii, was repeatedly dominant from late fall to the following spring (mean and maximum cell density, 2.3 × 103 $\pm$ 3.8 × 103, 4.5 × 105 cells $ml^{-1}$, respectively). Pinnate diatom, Aulacoseira granulata var. angustissima and A. italica, were frequently observed all season except January to March. Cyanobacteria, Microcystis aeruginosa and Aphanizomenon flos-aquae, proliferated in summer of 2002 except in 2003 due to heavy precipitation. The dominant zooplankton species (March-early May) was rotifer (Brachionus, Keratella, Polyarthra) and cladocerans (Diaphanosoma). The daily observed dynamics of the phytoplankton community in the lower Nakdong River in this study may play an important role in increasing the detailed resolution of limnological information and serving as ecological data for future studies.

• 한국대기환경학회지
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• 제27권5호
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• pp.485-493
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• 2011

In Korea, PM (Particulate Matter) emissions caused by coal-fired power plants are measured by a system, so called Clean Air Policy Support System (CAPSS), which uses foreign emission factors. However, the system fails to reflect the characteristics of domestic power plants. In this regard, this study aims to develop local, accurate domestic emission factors. The study measured the amount of TSP (Total Suspended Particulates), PM10 and PM2.5 by collecting samples from the latter parts of pollution control devices which were installed at 3 bituminous-fired power plants and 3 anthracite-fired power plants. The results showed that the average concentrations of TSP, PM10 and PM2.5 measured at bituminous-fired power plants were 4.63 mg/$Sm^3$, 2.96 mg/$Sm^3$ and 3.07 mg/$Sm^3$ respectively, much higher than those from anthracite-fired power plants (2.96 mg/$Sm^3$, 2.47 mg/$Sm^3$ and 1.37 mg/$Sm^3$, respectively). In addition, bituminous-fired power plants showed higher ratios of PM10/TSP and PM2.5/TSP with 0.66 and 0.92, respectively, compared to 0.82 and 0.46, the ratios of PM10/TSP and PM2.5/TSP measured in anthracite-fired power plants. Emission factors based-on concentration measurements were also higher for bituminous-fired power plants, and PM with smaller particles tended to have bigger difference in emission factors between the two fuels. This study calculated the amount of PM emissions by using the estimated emission factors. When it comes to the PM emissions, it was less than that of CAPSS while similar to that of CleanSYS in its amount. It is expected that the emission factors developed by this study will be used in Korea replacing foreign emission factors currently used in Korea by ensuring the objectivity and reliability as domestic emission factors.