• 대한원격탐사학회지
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• 제37권2호
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• pp.321-335
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• 2021

미세먼지 (PM10) 및 초미세먼지 (PM2.5)는 인체에 흡수 가능하여 호흡기 질환 및 심장 질환과 같이 인체건강에 악영향을 미치며, 심각할 경우 조기 사망에 영향을 줄 수 있다. 전 세계적으로 현장관측기반의 모니터링을 수행하고 있지만 미 관측지역에 대한 대기질 분포의 공간적인 한계점이 존재하여 보다 광범위한 지역에 대한 지속적이고 정확한 모니터링이 필요한 상황이다. 위성기반 에어로졸 정보를 사용함으로써 이러한 현장 관측자료의 한계점을 극복할 수 있다. 따라서 본 연구에서는 다양한 위성 및 모델자료를 활용하여 2019년도에 대해 한 시간 단위의 지상 PM10 및 PM2.5 농도를 추정하였다. GOCI 위성의 관측영역을 포함하는 동아시아 지역에 대해 트리 기반 앙상블 방법을 사용하는 Boosting 기법인 GBRTs (Gradient Boosted Regression Trees)와 LightGBM (Light Gradient Boosting Machine)을 활용하여 모델을 구축하였다. 또한, 기상변수 및 토지피복변수의 사용유무에 따른 모델의 성능을 비교하기 위해 두 가지 festure set으로 나누어 테스트하였다. 두 기법 모두 주요 변수인 AOD (Aerosol Optical Depth), SSA (Single Scattering Albedo), DEM (Digital Eelevation Model), DOY (Day of Year), HOD (Hour of Day)와 기상변수 및 토지피복변수를 함께 사용한 Feature set 1을 사용하였을 때 높은 정확도를 보였다. Feature set 1에 대해 GBRT 모델이 LightGBM에 비해서약 10%의 정확도 향상을 보였다. 가장 정확도가 높았던 기상 및 지표면 변수를 포함한 Feature set1을 사용한 GBRT기반 모델을 최종모델로 선정하였으며 (PM10: R2 = 0.82 nRMSE = 34.9%, PM2.5: R2 = 0.75 nRMSE = 35.6%), 계절별 및 연평균 PM10 및 PM2.5 농도에 대한 공간적인 분포를 확인해본 결과, 현장관측자료와 비슷한 공간 분포를 보였으며, 국가별 농도 분포와 계절에 따른 시계열 농도 패턴을 잘 모의하였다.

• 대한원격탐사학회지
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• 제36권6_3호
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• pp.1721-1732
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• 2020

초등학생들은 학교에서 많은 시간을 보내고 있으며 실내 공기오염에 더 많이 노출된다. 또한 초등학생들은 신체적으로 성장기에 있으며 어른에 비해 단위체중당 호흡량이 많으므로 실내 공기오염에 대한 민감도가 큰 것으로 알려져 있다. 따라서 학교 실내공기질은 초등학생들의 건강을 위한 중요한 요소이다. 본 연구에서는 서울지역 5개 초등학교에서 측정한 실내외 미세먼지 (Particulate matter: PM) 농도를 이용하여 상관분석을 실시하였다. 이를 통해 실외 PM이 실내 PM에 미치는 영향을 평가하였다. 또한 PM ratio, I/O ratio 등과 같은 통계분석을 진행하였다. 그 결과 초등학교의 실내외 PM의 상관성은 PM10보다 PM2.5와 PM1에서 더 유의미하게 나타났다. Indoor/outdoor (I/O) ratio의 경우 PM10에서 SD를 제외한 4개 초등학교에서 모두 1보다 높게 나타났다 (BB: 2.21, NS: 1.67, IS: 1.73, SI: 1.17). 이는 실내 학생의 활동도가 PM10의 농도에 큰 영향을 미친다는 것을 의미한다.

• 한국수정란이식학회지
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• 제25권1호
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• pp.15-20
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• 2010

본 연구에서는 OPU를 통한 체내 유래 난자를 이용한 수정란 생산 시 1개월에서 6개월까지의 연구 기간에 따른 난포 생성수, 난자 회수율, 난자 등급율, 배반포 생성률을 분석하여 공란우의 활용 기간에 관하여 조사하였다. 1. 채란 기간에 따른 난포 생성수는 1개월에서 5개월까지의 난포 생성수는 $7.78{\pm}0.57$, $9{\pm}0.68$, $6.96{\pm}0.60$, $7.18{\pm}0.83$, $6.19{\pm}0.82$개로 유의적인 차이가 없었으나, 6개월째에는$2.83{\pm}0.39$개로 급격하게 줄어든 것을 알 수 있었다. 2. 채란 기간에 따른 난자 회수개수는 1개월에서 3개월까지는 $6.0{\pm}0.5$, $6.2{\pm}0.7$, $5.2{\pm}0.6$개로 유의적인 차이가 없었으나, 4개월부터 6개월까지 $3.7{\pm}0.5$, $2.8{\pm}0.4$, $1.2{\pm}0.2$개로 유의적으로 적어지는 것을 알 수 있었다. 난자 회수율 또한 1개월에서 3개월까지는 76.9%, 69.3%, 75.2%로 유의적인 차이가 없었으나, 4개월에서 6개월까지는 51.1%, 44.6%, 41.2%로 유의적으로 낮아지는 것을 알 수 있었다. 3. 채란 기간에 따른 난자 등급은 Grade 1, 2등급 출현율이 1개월부터 3개월까지 Grade 1은$1.8{\pm}0.3$, $2.2{\pm}0.3$, $1.9{\pm}0.3$, Grade 2는 $2.1{\pm}0.3$, $2.4{\pm}0.3$, $2.1{\pm}0.3$로 유의적으로 차이가 없었으나, 4개월, 5개월에는 Grade 1은 $1.73{\pm}0.27$, $1.14{\pm}0.33$, Grade 2는 $1.33{\pm}0.28$, $0.67{\pm}0.16$로 유의적으로 줄어들었으며, 6개월에는 Grade 1은 $0.3{\pm}0.1$, Grade 2는 $0.5{\pm}0.2$로 현저히 줄어든 것을 알 수 있었다. Grade 3과 4의 출현율은 유의적으로 차이가 없었다. 4. 채란 기간에 따른 배반포 발달율은 1개월에서 3개월까지의 배반포 발달율은 37.2%, 40.4%, 44.6%로 높은 발달율을 보이며 차이가 없었으나, 4개월째에는 24.8%, 5개월째에는 29.3%, 6개월째에는 28.6%로 급격하게 줄어드는 것을 알 수 있었다. 1회 채란 시 수정란의 생산 개수 또한 1개월에서 3개월까지는 $2.2{\pm}0.3$, $2.5{\pm}0.3$, $2.3{\pm}0.4$개로 유의적인 차이가 없었으나, 4개월째부터 6개월까지는 $0.9{\pm}0.2$, $0.8{\pm}0.2$, $0.3{\pm}0.2$개로 현저히 줄어드는 것을 알 수 있었다. 이상의 결과에서 약 3개월까지는 공란우의 활용이 효율적인 점과 4개월부터는 난자 회수와 그에 따른 1회 채란 시 배반포의 생성 수 또한 점차 적으로 줄어드는 것을 알 수 있었다. 따라서, 공란우의 활용을 최대 3개월까지 활용하고, 교체한다면 3~4일 간격으로 1주일에 2회 OPU 방법으로 체내 난자를 채란 후 수정란을 생산하는 시스템은 1두에 3개월간 약 48개의 이식 가능한 수정란을 생산할 수 있고, 산술적으로 년간 1두당 약 200개의 이식 가능한 OPU 유래 수정란을 생산할 수 있을 것이다. 따라서 공란우를 3개월 활용 후 교체를 하는 것이 경제적이며 효율적인 방법이라고 사료된다.

• 한국대기환경학회지
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• 제34권4호
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• pp.534-541
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• 2018

Concentrations of total particulate matter (TPM), $PM_{10}$ and $PM_{2.5}$ were measured at three different sites based on each different fuel type (solid, liquid and gas) used in thermal power plants operating in Yeosu and Gwangyang National Industrial Complexes during 2017. The highest concentrations of TPM, $PM_{10}$, and $PM_{2.5}$ were observed at the solid fuel facility, and these values were $3.356mg/Sm^3$, $2.342mg/Sm^3$ and $1.834mg/Sm^3$, respectively. The ratio of $PM_{2.5}$ to TPM was the highest value of 54.6% in solid fuel case, and the lowest was 35.7% found in liquid fuel case. As a result of analyzing 9 kinds of metal compound with respect to each particle size, the metal concentration of TPM is higher than those of $PM_{10}$ and $PM_{2.5}$ in all fuel types. Total concentrations of metal elements in TPM by fuel difference are $1.2702mg/Sm^3$ in solid fuel, 0.0603 mg/Sm3 in liquid fuel, and $0.0733mg/Sm^3$ in gas fuel, respectively. Relatively higher total metal concentration in gas fuel than in liquid fuel was found; and this could be higher Cr and Al concentrations in use of gas fuel. As a result of estimating the emission factors of each facility, in case of solid fuel, TPM emissions per electricity production were found to be 0.7080 kt/PJ, followed by liquid fuel and gas fuel. $PM_{10}$ and $PM_{2.5}$ emissions per hour of electricity production were similar to those of TPM.

• Natural Product Sciences
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• 제14권1호
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• pp.1-11
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• 2008

Peroxynitrite ($(ONOO^-)$ is a cytotoxic species formed from nitric oxide and superoxide anion, which are highly implicated in the pathogenesis of oxidative stress-mediated diseases. The aim of this study was to investigate the scavenging effects of Phellinus linteus on authentic $ONOO^-$, and further phytochemical studies are planned that will attempt to identify the active principles. From the active EtOAc fraction, a mixture of fungisterol and 5-dihydroergosterol (1), a mixture of betulin and 1,2-benzenedicarboxylic acid bis (2-methyl heptyl) ester (2), protocatechualdehyde (3), protocatechuic acid (4), cirsiumaldehyde (5), hispidin (6), caffeic acid (7), phelligridin D (8), uracil (9), gallic acid (10), 2,5-dihydroxybenzoic acid (11), ferulic acid (12), 2,3-dihydroxybenzaldehyde (13), arbutin (14), isoferulic acid (15), guanosine (16), and ellagic acid (17) were isolated, and their structures were characterized based on spectroscopic data. All compounds except 3, 6, 7 and 16 were isolated for the first time from P. linteus. Compounds 3, 4, 6-8, 10-15, and 17 showed potent scavenging activity on $ONOO^-$, with $IC_{50}$ values of $2.06\;{\pm}\;0.10$, $3.45\;{\pm}\;0.57$, $0.71\;{\pm}\;0.05$, $2.78\;{\pm}\;0.36$, $5.42\;{\pm}\;0.26$, $1.13\;{\pm}\;0.02$, $1.82\;{\pm}\;0.17$, $0.91\;{\pm}\;0.19$, $1.59\;{\pm}\;0.09$, $1.88\;{\pm}\;0.07$, $1.22\;{\pm}\;0.37$, and $2.01\;{\pm}\;0.02\;{\mu}M$, respectively, as compared to the positive control, DL-penicillamine, with an $IC_{50}$ value of $5.04\;{\pm}\;0.06\;{\mu}M$.

• 한국지리정보학회지
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• 제25권2호
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• pp.1-17
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• 2022

본 연구는 경상남도 창원시 국가산업단지 인근에 설치된 21개의 PM_2.5 간이 측정기에서2020년 6월부터 2021년 5월까지 1년 동안 측정된 자료를 활용하여 PM_2.5의 발생 패턴을 분석하였다. PM_2.5의 발생 패턴은 측정지점 주변의 토지이용현황과 기온 및 풍속의 기상적인 요인을 고려하였다. PM_2.5 농도는 계절별로는 겨울철인 11월부터 3월까지, 시간대별로는 새벽과 이른 아침인 1시부터 9시까지가 높았다. PM_2.5는 공업지역에 인접할수록 농도가 높았으나, 주거지역과 공공시설지역은 농도가 낮았다. 기상적인 요인에서는 높은 기온과 풍속일수록 PM_2.5의 농도는 낮았기 때문에 기상 상태는 PM_2.5의 확산에 영향을 미치는 것으로 판단된다. 본 연구의 결과는 창원국가산업단지 인근의 PM_2.5 발생 패턴을 파악할 수 있었다. 이 결과는 향후 도시지역의 PM_2.5를 포함한 대기질을 개선하기 위해 도시 및 환경계획에서 활용할 수 있는 유용한 자료가 될 것이다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권4호
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• pp.221-228
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• 2017

Objectives: The purpose of this study was to establish normative data for healthy Korean adults by measuring the maximal strength and endurance scores of the tongue, lip, and cheek, and to examine correlations between these measurements. Materials and Methods: This study included 120 subjects that were divided into three groups according to age: young (20-39 years), middle-aged (40-59 years), and older (over 60 years); and by gender. Measurements were taken using the Iowa Oral Performance Instrument (IOPI). Results: The mean maximal tongue strengths were as follows: young men ($46.7{\pm}10.2kPa$) and women ($32.1{\pm}7.9kPa$), middle-aged men ($40.9{\pm}9.3kPa$) and women ($36.9{\pm}8.6kPa$), and older men ($35.2{\pm}9.0kPa$) and women ($34.5{\pm}6.9kPa$). The mean tongue endurance scores were: young men ($28.8{\pm}12.6$ seconds) and women ($20.8{\pm}13.5$ seconds), middle-aged men ($17.0{\pm}8.5$ seconds) and women ($15.3{\pm}5.2$ seconds), and older men ($15.8{\pm}6.7$ seconds) and women ($17.9{\pm}8.1$ seconds). The mean maximal lip strengths were: young men ($11.6{\pm}3.0kPa$) and women ($11.4{\pm}3.8kPa$), middle-aged men ($11.4{\pm}4.2kPa$) and women ($11.1{\pm}5.1kPa$), and older men ($14.5{\pm}3.9kPa$) and women ($11.7{\pm}2.6kPa$). The mean lip endurance scores were: young men ($41.1{\pm}23.9$ seconds) and women ($22.4{\pm}21.7$ seconds), middle-aged men ($24.3{\pm}10.3$ seconds) and women ($30.5{\pm}13.4$ seconds), and older men ($24.9{\pm}11.0$ seconds) and women ($12.8{\pm}7.6$ seconds). The mean maximal cheek strengths were: young men ($24.5{\pm}4.6kPa$) and women ($20.5{\pm}4.3kPa$), middle-aged men ($25.2{\pm}6.4kPa$) and women ($21.2{\pm}5.5kPa$), and older men ($22.4{\pm}5.3kPa$) and women ($18.0{\pm}4.8kPa$). The mean cheek endurance scores were: young men ($47.8{\pm}24.4$ seconds) and women ($43.9{\pm}25.0$ seconds), middle-aged men ($27.3{\pm}11.3$ seconds) and women ($20.0{\pm}14.6$ seconds), and older men ($21.7{\pm}14.5$ seconds) and women ($17.2{\pm}11.4$ seconds). Conclusion: The data collected in this study will provide an important database of standardized measurements for maximal strength and endurance scores of the tongue, lip and cheek in healthy, normal Koreans.

• Journal of Chest Surgery
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• 제25권2호
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• pp.125-130
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• 1992

To evaluate the effect of oxygenation[95% O2+5% CO2] of St. Thomas Hospital No.2 cardioplegic solution[Plegisol], 20 isolated perfused rat hearts were studied under hyp-othermic[20oC] ischemic arrest for 2 hours with infusion of cardioplegic solution every 30 minutes throughout the ischemic period. Ten isolated hearts were studied with the oxygenated cardioplegic solution and 10 another isolated hearts with the nonoxygenated one. Mean oxygen tensions of the nonoxygenated and oxygenated cardioplegic solutions were 150mmHg and 470mmHg, respectively. Two in 10 hearts infused with the nonaxygenated cardioplegic solution were not recovered from nonworking heart due to persistent ventricular fibrillation. In comparing hem-odynamic parameters between both groups, the mean postischemic recovery[expressed as a percentage of its preischemic control value] was significantly greater with the oxygenated solution[in 10 recovered hearts] than the nonoxygenated solution[in 8 recovered hearts] [95.9$\pm$1.8% compared with 88.5$\pm$2.9% in peak aortic pressure, p<0.05, 75.7$\pm$5.2% compared with 43.5$\pm$6.5% in aortic flow, p<0.01, 75.5$\pm$4.6% compared with 54.1$\pm$5.6% in cardiac output, p<0.01, 78.3$\pm$4.6% compared with 60.3$\pm$4.6% compared with 60.3$\pm$6.2% in stroke volume, p<0.05, and 80.4$\pm$5.3% compared with 58.6$\pm$7.0% in dP/dT, p<0.05]. It is concluded that oxygenation of St. Thomas Hospital No.2 cardioplegic solution improves cardiac electrical stability and postischemic hemodynamic recovery after ischemic arrest in the isolated perfused rat heart.

• 한국대기환경학회지
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• 제34권3호
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• pp.406-417
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• 2018

In this study, $PM_{2.5}$ samples were collected during approximately 3 years in Chuncheon, a small residential and tourist city, in Korea. The average $PM_{2.5}$ concentration was $26.9{\mu}g/m^3$, exceeding the annual national air quality standard. $PM_{2.5}$ showed typical seasonal variation, having higher concentration in winter and lower concentration in summer. Sixteen metallic elements in $PM_{2.5}$ were also analyzed, and K was the highest contributor especially in late fall and winter. In addition, K considerably increased for the top 10% of $PM_{2.5}$ samples and showed the highest correlation coefficient with $PM_{2.5}$ among all other metallic elements. These results suggest that the combustion of agricultural residue and other biomass, the major source of K was likely to be important to high $PM_{2.5}$ concentration events in this city. Crustal elements including Al, Fe, Si, Ti, Mg showed high concentration in spring while Cr, Cu and Ni were relatively consistent throughout a year. Principal component analysis was used to trace the sources, and soil re-suspension, combustion of biomass and fossil fuels, and asphalt concrete production were identified as the main sources of $PM_{2.5}$.

• Journal of Preventive Medicine and Public Health
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• 제20권1호
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• pp.97-113
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• 1987

This study was carried out to know physical growth and development, physical and nutritional indices and body fat weight and so forth by semi-longitudinal research method to measure body height, body weight, chest girth and sitting height of 260 of general high school and 306 of vocational high school 3rd grade students who are living in Seoul and born from 1966 March 1st to 1967 Feb.28th. The results are as follows: 1) Physical growth and development Growth in terms of body height showed one step straight linear development, andthat of body weight showed two step straight linear development in each section in high school. The age of cross over between two sexes of general high school students was between 10.6 to 12. 3 years in body height, between 10.8 to 13 years in body weight, between 11.2 to 14.6 years in chest girth and between 10 to 13 years in sitting height. The age of cross over between two sexes of vocational high school students was between 10.5 to 12.5 years in body height, between 10.5 to 12.5 years in body weight, between 10.5 to 12.5 years in chest girth and between 10.5 to 12.5 years in sitting height. In this periods, female group was superior to male group and after that male group was superior to female group again. The growth of vocational school students was superior to that of general school students in both sexes in terms of body height and body weight significantly. 2) Physical growth and nutritional indices In all cases of relative body weight, relative chest girth and relative sitting height, it was found to be increasing thereafter with advancing ages. In cases of $R{\"{o}}hrer$ index and Kaup index, it was found to be reaching to normal state thereafter with advancing ages. In each case of Vervaeck and Pelidisi index, it was found to be increasing and reaching to normal state thereafter with advancing ages. 3) Total body fat by vital measuring method Average values of body surface area, body volume and body density are measured indirectly by using the body height and body weight as Table 12, 13 and 14. The rate of body fat weight of general high school students was from minimum $11.96{\pm}3.53%(3.33{\pm}1.10kg$) to maximum $18.25{\pm}6.46%(9.08{\pm}2.01kg$) in male and from $25.88{\pm}3.62%(7.96{\pm}0.78kg$) to $43.00{\pm}7.22%(12.91{\pm}1.21kg$) in female. The rate of body fat weight of vocational high school students was from minimum $11.20{\pm}2.88%(3.32{\pm}1.13kg$) to maximum $17.16{\pm}5.88(10.83{\pm}3.16kg$) in male and from minimum $25.11{\pm}2.26%(7.91{\pm}0.89kg$) to maximum $42.16{\pm}7.96%(13.22{\pm}1.75kg$) in female.