율촌 LNG 발전소의 공냉식 복수기 사용에 따른 열확산 수치모의

김유근,이화운,문윤섭,황미경 부산대학교 환경문제연구소 2000 環境硏究報 Vol.18 No.-

In this study, thermal diffusion caused by using air cooled condenser at LNG power plant in Yulchon was simulated through in numerical method (Matsuno scheme). The input data of model was used to seasonal wind components (u, v) of automatic weather system (AWS) and seasonal temperature ranges between inflow and outflow of opening air. The aim of this study was twofold : (1) to investigate sensibility analysis of thermal diffusion coefficient : (2) to simulate diffusion of heat source through the calculated effect height for season and stability variations. These sensibility analyses were performed in detail using two case studies one is to apply horizontal and vertical thermal diffusion coefficient as 50 m-ls-1 and 10 m-ls-1, the other is 30 m-ls-1 and 10 m-ls-1 respectively. It is well known that the sensibility for thermal diffusion coefficient is low owning to very similar results. Consequently, thermal diffusion for the first case is simulated by using effect height for season and stability variation. The temperature is under 1℃ at surface whereas that is high at near the center of effect height.

신경망을 이용한 공정 오차 보정

전경아,유지용,오혜근 한양대학교 이학기술연구소 2002 이학기술연구지 Vol.5 No.-

패턴의 미세화에 따른 정확하고 신속한 결과 예측은 Iithography simulation tool 의 높은 공정 변수 의존을 요구한다. 이로 인해 simulation tool 은 공정 변수 사이의 보정이 더욱 복잡해져 광 근접 효과 등으로 나타나는 다양한 패턴들의 크기 결과를 예측하는데 많은 어려움을 겪게된다. 이에 본 논문에서는 simulation 결과 값과 실측값의 차이를 신경망 알고리즘에 적용하여 공정 변수를 최적함으로서 simulation tool의 예측 정확성을 향상시키는 방법을 제시하였다. It is required to make an accurate and quick prediction of critical dimension (CD)for higher integrated devices. Because simulation tools consist of many process parameters and models, it is difficult that process parameters are calibrated to match the CD results for various patterns. This paper presents a method of improving the accuracy of predicting CD results by applying △ (the difference between simulation and experimental data) value to neural network algorithm (NNA) in order to reduce the CD difference caused by optical proximity effects.

신고리 지역 기상관측을 통한 계절별 대기안정도 특성분석

송상근,김유근,오인보,정주희,조윤미,우경은,강태훈 부산대학교 환경문제연구소 2003 環境硏究報 Vol.21 No.-

In this study, we analyzed the characteristics of atmospheric stability to investigate local environment change at an atomic power plant in Gori region. The used data was obtained from field observation of major meteorological variables such as wind direction and speed, air temperature, relative humidity, and solar radiation using AWS (Automatic Weather System) in Gori region from February to September in 2003. As a result, when strong northerly winds (more than 4~6 m/s) and weak northwesterly winds (2~3m/s) blow, atmospheric stability was neutral and stable from winter to spring, respectively. Atmospheric stability (neutral) in summer was similar to that in two other seasons (winter and spring), but it was stable for weak southwesterly winds (2~3 m/s). Finally, atmospheric stability was neutral for strong winds (over 4~6 m/s) in fall without respect to wind direction, while that was stable for very weak winds (less than 2 m/s).

창원지역에서의 대기오염물질 배출량 산정

김유근,박상철,문윤섭,오인보,황미경 부산대학교 환경문제연구소 2002 環境硏究報 Vol.20 No.-

Emissions of air pollutants (TSP, SO2, NO2, CO, and HC) was estimated in Changwon city that has the industrial complex and basin terrain. We found that the emissions of TSP, SO2, NO2, CO, and HC were 897 tons, 3,287 tons, 5,706 tons, 10,057 tons, and 1,470 tons for a year, respectively and the main source of air pollutants were vehicle. The ratios of vehicle emissions to total emissions ware TSP 63.8%, SO2 26.1%, NO2 65.5%, CO 91.0%, HC 94.4%. The ratios of industry emissions to total emissions were TSP 30.8%, SO2 60.2%, NO2 25.2%, CO 6.4%, HC 3.7%. The ratio of life emissions to total emissions are TSP 5.4%, SO2 13.7%, NO2 9.3%, CO 2.6%, HC 1.9%. The concentration distributions of air pollutants simulated by ISCST3 model were similar to its emission distributions, and relatively high concentrations of air pollutants occurred in the Palyong-dong (industrial area) and Banlim and Chungang (residual area).

서울과 부산지역 기상의 영향을 제거한 오존농도 추세

김유근,오인보,황미경 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.5

Surface ozone concentrations are highly sensitive to meteorological variability. Therefore, in order to reveal the long-term changes in ozone due to the changes in precursor emissions, we need to remove the effects of meteorological fluctuations on the annual distribution of surface ozone. In this paper, the meteorologically adjusted trends of daily maximum surface ozone concentrations in two major Korean cities(Seoul and Busan) are investigated based on ozone data from II(Seoul) and 6(Busan) sites over the period 1992~2000. The original time series consisting of the logarithm of daily maximum ozone concentrations are splitted into long-term, seasonal and short-term component using Kolmogorov-Zurbenko(KZ) filter. Meteorological effects are removed from filtered ozoned ozone series using multiple linear regression based on meteorologcial variables. The long term evolution of ozone forming capability due to changes in precursor emission can be obtained applying the KZ filter to the residuals of the regression. The results indicated that meteorologically adjusted long-term daily maximum ozone concentrations had a significant upward trend(Seoul:+3.02%yr¹, Busan: +3.45%yr¹). These changes of meteorologically adjusted ozone concentrations represent the effects of changing background ozone concentrations as well as the more localized changes in emissions.

연안도시지역 해풍지연이 오존분포에 미치는 영향

오인보,김유근,황미경 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.3

The late sea-breeze and its impacts on ozone distributions were investigated during April to September from 1998 to 2002, in the Busan metropolitan area (including surrounding areas) using the surface ozone concentrations (obtained at 9 monitoring sites), local meteorological variables (obtained near the shore), together with synoptic data. The urban scale ozone concentration was also simulated using the MM5/UAM-V to better understand the role of late sea-breeze in Busan. The results from observation study showed that most of the late sea-breeze occurred when weak offshore synoptic flow (northwesterly) suppressed development of sea-breeze, and the ozone concentration level and frequencies exceeding ozone standard increased with the onset time of sea breeze. We also found that the late sea-breeze clearly induces relatively weak wind speed and high temperature during the daytime. As a result it enhances the photochemical ozone accumulation and delays the occurrence time of the averaged maximum ozone concentrations. The results of simulation for high ozone episode (24 August, 2001) by MM5/UAM-V revealed that the late sea-breeze interacted with weak offshore synoptic wind can contribute significantly to high ozone concentration in the coastal urban area. The simulated horizontal and vertical distribution of ozone concentration indicated that ozone can be accumulated over the sea under stagnant condition and return to the land in the late afternoon with the sea breeze, suggesting both the relationship between late sea-breeze and recirculation and the importance of late sea-breeze effects influencing severe ozone pollution in Busan.

지표면 wetness에 따른 오존의 건성침적속도 특성

이화운,김유근,문난경 한국환경과학회 2003 한국환경과학회지 Vol.12 No.4

It has been researched the relationship between deposition velocity and factors which could affect the deposition phenomena and deposition velocity also has been estimated for several land-use types. The typical deposition velocities are complex functions of surface types, atmospheric stabilities, friction velocities, air pollutants and so on. The canopy resistance is major contribution to the model's total resistance for O_3. Canopy wetness is also an important factor to calculate deposition velocity, We considered the canopy wetness as canopy water content(CWC) in our Model, But, it is not easy to observe CWC over each land-use types. In this study, we use CWC observed by EMEFS(CANADA Environment Service, 1988) to examine the influence of CWC in estimation of O_3 dry deposition velocity(V_4) in summertime. The value of O_3 V_4 range 0.2~0.7㎝ s^-4 on dry surface and 0.01~0.35㎝ s^-4 on wet surface in daytime.

Removal of Mn Ions by Biological Co-precipitation of Fe Ions

Yoo, Kyoung-Keun,Hiroyoshi, Naoki,Tsunekawa, Masami 한국암반공학회 2010 Geosystem engineering Vol.13 No.3

The behaviors of manganese ions during biological precipitation of iron ions by Acidithiobacillus ferrooxidans was investigated to remove the Mn ions from acid mine drainage. The effect of initial $Fe^{2+}$ ion concentration with $900g{\cdot}m^{-3}$, $4500g{\cdot}m^{-3}$, and $9000g{\cdot}m^{-3}$ on the removal of Mn ions was examined by measuring pH, ORP, and the concentrations of Fe and Mn ions. In the experiments with the $Fe^{2+}$ concentration with $4500g{\cdot}m^{-3}$ and $9000g{\cdot}m^{-3}$, pH increased and then decreased by the oxidation of $Fe^{2+}$ and the precipitation of Fe ions. In all solutions, ORP increased to 630 mV, and Fe concentration decreased with Fe precipitation. Adding NaOH increased the amount of Fe precipitate and the Mn removal ratio in the early stage but there was no significant effect as the experiments were proceeded.

철산화박테리아에 의해 생성된 침전물에 의한 망간이온의 제거

유경근 ( Kyoung Keun Yoo ),지상우 ( Sang Woo Ji ),이재천 ( Jae Chun Lee ) 한국공업화학회 2006 응용화학 Vol.10 No.2

기술 개발 동향 : 폐액정디스플레이 제품의 재활용 기술개발 동향

유경근 ( Kyoung Keun Yoo ),홍현선 ( Hyun Seon Hong ),조봉규 ( Bong Gyoo Cho ) 한국전과정평가학회 2011 한국전과정평가학회지 Vol.12 No.1

액정디스플레이는 브라운관 텔레비전을 급속히 대체하고 있으며 다양한 소형전자기기의 핵심부품으로서 사용량이 급증하고 있어 향후 폐액정디스플레의 발생량 증가가 예상되고 있다. 현재 재활용 기술 및 시스템의 미비로 폐액정디스플레이의 대부분이 소각 · 매립 처리되고 있어 유용자원의 손실 및 환경오염에 대한 우려가 가중되고 있다. 이 글에서는 각 국의 재활용 정책방향 및 기술개발방향을 정리하여 국내 폐디스플레이 재활용 기술개발의 방향을 제시하고자 하였다. Liquid crystal display has substituted for cathode ray tube (CRT) and has been widely used in small electronic equipments, arid It is expected that the amount of spent liquid crystal display (LCD) increases in future. There is increasing concern about the loss of valuable resources and the contamination of surrounding environment because the most of the spent LCD has been incinerated and landfilled due to incomplete recycling technologies and system for the spent LCD. The present article suggest the development direction of recycling technology of spent LCD summarizing policy and technologies for the recycling of spent LCD.