• 한국환경과학회지
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• 제14권5호
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• pp.463-471
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• 2005

This study is designed to investigate the characteristics of $PM_{10}$ concentration and the chemical composition of heavy metallic components in the $PM_{10}$ sampled in western Busan from March to May, 2003. $PM_{10}$measurement was done during springtime of 2003, totaling 29 days: 9 days in March, 10 days in April and 10 days in May. With a sampling time of 24 hours, it started 9:00 AM on that day and ended 9:00 AM the next day. The mean contribution ratio of soil during springtime was $10.3\%$. Al had a significant correlation with Ca, Fe, Mg and Si and little correlation with Na, Ni and Zn.

• Journal of the Optical Society of Korea
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• 제8권1호
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• pp.1-5
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• 2004

Using the external cavity spectroscopy method, we have observed the saturated absorption spectrum of the P(16) line of the v$_1$+v$_3$ band of $^{13}C$_2$H$_2$$. The frequency of a laser has been stabilized to the saturated absorption spectrum. The relative contrast of the saturation spectrum is about 7% with respect to the linear absorption and the linewidth is about 1.8 MHz. The frequency fluctuation of the stabilized LD is about $\pm$ 20 KHz for a sampling time of 100 ms.

• 한국환경과학회지
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• 제30권10호
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• pp.845-861
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• 2021

This study investigated the variations in monthly PM_2.5 concentrations and their characteristics at the sampling site (35.075°N, 129.080°E) around the Busan seaport area for six months (from August 2020 to January 2021). Monthly PM_2.5 concentrations in the filtered samples ranged from 8.4 to 42.3 ㎍/m³ (average=19.6±8.2 ㎍/m³, n=50) and were generally high in August, December, and January, and low in September, October, and November. The variations of monthly PM_2.5 concentrations showed similar patterns to those of the neighboring national air quality monitoring sites. The contents of Total Carbon (TC), Organic Carbon (OC), Elemental Carbon (EC), and OC/EC ratios in PM_2.5 showed large variability during the study period. The OC/EC ratios ranged from 4.2 to 34.4, suggesting that the relative contributions of OC and EC to the PM_2.5 concentrations changed temporally and might be related to their formation sources. Variations in the chemical components of and particle size distributions in PM_2.5 showed that high PM_2.5 concentrations were affected by various sources, such as sea salt and ship emission. The precursor gas concentrations were discussed in terms of monthly variations and their contributions to PM_2.5 concentrations. However, further research is needed to understand the characteristics and behaviors of PM_2.5 concentrations around the Busan seaport area.

• 한국대기환경학회지
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• 제27권1호
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• pp.16-29
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• 2011

The cyclone/annular denuder system/filter pack sampling system (ADS) was used to collect data set of the acidic air pollutants in the vicinity of industrial complexes in Gwangyang. The data set was collected during sixty different days with 24 hour sampling period from January 8, 2008 through November 12, 2008. The annual mean concentrations of $HNO_3$, $HNO_2$, $SO_2$ and $NH_3$ in the gas phase were 1.12, 1.40, 10.2 and 1.28 ${\mu}g/m^3$, respectively. The annual mean concentrations of $PM_{2.5}$ ($d_p$<2.5 ${\mu}m$), $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ in the particulate phase were 29.2, 8.25, 3.30 and 3.42${\mu}g/m^3$, respectively. $HNO_3$ and $NH_3$ exhibited higher concentrations during the summer, while $HNO_2$, $PM_{2.5}$, $NO_3^-$ and $NH_4^+$ were higher during the winter. The highest level of $SO_2$ was, unlikely, observed in the summer and $SO_4^{2-}$ was not showed seasonal variation. $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ accounted for 49~57% of the $PM_{2.5}$ mass. $SO_4^{2-}$ was the most abundant component, which constituted 23~40% of $PM_{2.5}$. High correlations were found among $PM_{2.5}$, $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$.

• 전자공학회논문지
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• 제50권3호
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• pp.113-121
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• 2013

본 논문은 학습 기반의 2D-FIR필터를 이용한 부화소 렌더링 기법을 제안한다. 제안 기법은 크게 학습 단계와 합성 단계로 나뉜다. 학습 단계에서는 충분히 많은 수의 저해상도/고해상도의 영상 블록 쌍들을 이용하여 고해상도/저해상도 블록의 관계에 따른 합성 정보를 계산하고, 그 합성 정보를 담은 소위 사전을 생성한다. 합성 단계에서는 각 입력 영상에 대응하는 후보 블록을 상기 학습된 사전에서 찾는다. 탐색된 사전 내 합성 정보를 이용하여 부화소 레벨의 축소된 블록을 합성함으로써 최종 축소 영상을 얻는다. 한편, 영상 합성 시 디스플레이 장치의 RGB 패턴을 고려한 필터링을 통해 선명도를 향상시킨다. 모의 실험을 통해 제안 기법이 일반적인 영상축소 기법에 비해 흐림 효과, 엘리어싱 등의 화질 열화없이 고화질의 축소 영상을 생성함을 확인하였다.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.123-134
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• 2020

The interaction between UN and CdCl₂ in the LiCl-KCl molten eutectic was studied at 773 K. The reaction was controlled by sampling the melt, as well as by analysis of the resulting precipitate. The process was shown to proceed according to several parallel reactions. The summary reaction was determined to have two stages: a fast one and a slow one. The 19-53% UN → UCl₃ conversion was obtained for the molar ratio of CdCl₂/UN = 1.22-14.9. The rest of UN converts into the precipitate of complex composition (UNCl + U₂N₃ + U₄N₇ + UN₂). The increase in the CdCl₂/UN molar ratio from 1.22 to 14.9 resulted in the decrease in duration of the first "fast" stage of the process from 18 h to 1 h.

• 한국산업보건학회지
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• 제31권4호
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• pp.331-341
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• 2021

Objectives: The aim of this study was to evaluate the concentrations and relationships of coarse particles with a diameter of 10 ㎛ (PM₁₀) with endotoxins according to the time of measurement in windowless poultry houses. Methods: In this study, measurement was performed on ten windowless poultry houses with a vertically integrated system from July to November. PM₁₀ was measured using personal environmental monitors and polytetrafluoroethylene (PTFE) filters with a 4 L/min-calibrated pump in selected sampling locations (two near the door and two near an exhaust fan). The endotoxin on PTFE filter was analyzed by the LAL turbidimetric method. Results: The range of geometric mean concentrations of PM₁₀ and endotoxins for each of the 38 samples were 0.12-3.30 mg/m³ and 11.9-3553.66 EU/m³, respectively. PM₁₀ and endotoxin concentrations varied by farm, increasing with the decrease in ventilation. The range of the coefficient of determination between PM₁₀ and endotoxin was 0.0009-0.9249. As the atmospheric temperature decreased, it was confirmed that the concentrations of PM₁₀ and endotoxin increased because the volume of ventilation was decreased. Conclusions: Endotoxins were more affected by time of measurement and ventilation than PM₁₀, which means that endotoxins could be an important indicator for intervention programs for improvement of indoor environments.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.64-73
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• 2022

Increasing carbon and PM_2.5 concentrations have been emerging as serious environmental issues worldwide. The purpose of this study was to quantify carbon and PM_2.5 reduction by urban parks in Gangneung, Korea. A total of 35 parks were sampled by applying a random sampling method to survey tree planting structures and the areal distribution of land cover types of urban parks. These survey data and the Green Evaluation Technique (GET) computer program were used to estimate carbon and PM_2.5 reduction by trees. Mean tree density and cover in the study parks were 3.5±0.2 tree/100 m² and 44.5±3.0%, respectively. Annual carbon uptake and PM_2.5 deposition per unit area by trees averaged 2.8±0.2 t/ha/yr and 30.2±2.8 kg/ha/yr. Gangneung's urban parks annually offset the carbon emissions by 3.4% and the PM_2.5 emissions by 3.5%. Thus, urban parks played a significant role in reducing atmospheric carbon and PM_2.5 concentrations. Total annual carbon uptake and PM_2.5 deposition of urban parks in Gangneung were about 1,338.2 t/yr and 14,433.2 kg/yr. This study is expected to contribute to raising awareness of the role and importance of urban parks regarding carbon and PM_2.5 reduction.

• 한국임상약학회지
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• 제33권3호
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• pp.195-201
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• 2023

Background: Hematocrit is usually measured from venous blood collected by invasive venipuncture. This study was performed to determine hematocrit accurately and precisely using minimally invasive volumetric absorptive microsampling (VAMS) technique. Such technique is to be applied to determining hematocrit in various clinical settings for the care, including therapeutic drug monitoring, of neonatal or epileptic patients, or patients with high risk of infection or bleeding. Methods: The study was performed using 31 VAMS samples obtained from 21 pancreatic cancer patients. Hematocrit was determined using the values of potassium concentrations obtained from blood in VAMS tips (Hct_VAMS). Hct_VAMS was compared with hematocrit measured from blood collected by venipuncture (Hct_VP). The accuracy and precision of Hct_VAMS in comparison to Hct_VP were evaluated using Bland-Altman plot, Deming regression and mountain plot. Results: Bland-Altman plot displayed a random scattering pattern of the differences between Hct_VAMS and Hct_VP with the mean bias of -0.010 and the 95% limit of agreement ranging from -0.063 to 0.044. Deming regression for Hct_VAMS and Hct_VP line demonstrated very small proportional and constant biases of 1.04 and -0.003, respectively. Mountain plot exhibited a narrow and symmetrical distribution of the differences with their median of -0.011 and central 95% range from -0.049 to 0.033. Conclusion: Hematocrit was accurately and precisely determined using less invasive VAMS technique. Such technique appears to be applicable to determining hematocrit in situations that venipuncture is not favorable or possible.

• 제어로봇시스템학회논문지
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• 제6권3호
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• pp.317-328
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• 2000

This paper presents an effective approach to collision-free motion planning of a robot in the work-space including time-varying obstacles. The free arc is defined as a set composed of the configuration points of the robot satisfying collision-free motion constraint at each sampling time. We represent this free arc with respect to the new coordinate frame centered at the goal configuration and there for the collision-free path satisfying motion constraint is obtained by connecting the configuration points of the free arc at each sampling mined from the sequence of free arcs the optimality is determined by the performance index. Therefore the complicated collision-free motion planning problem of a robot is transformed to a simplified SUB_Optimal Collision Avoidance Problem(SOCAP). We analyze the completeness of the proposed approach and show that it is partly guaranteed using the backward motion. Computational complexity of our approach is analyzed theoretically and practical computation time is compared with that of the other method. Simulation results for two cally and practical computation time is compared with that of the other method. Simulation results for two SCARA robot manipulators are presented to verify the efficacy of the proposed method.