간척담수호 저층퇴적물의 오염물질 용출특성

정광욱,윤춘경,이인호,이승일,강수만,함종화,Jung, Kwang Wook,Yoon, Chun Gyeong,Lee, In Ho,Lee, Seung Il,Kang, Su Man,Ham, Jong Hwa 한국농공학회 2014 한국농공학회논문집 Vol.56 No.1

Sediment pollutants have been considered an important source for the eutrophication of estuarine reservoir. In this study, the effects of pollutants released from bottom sediment to water column were investigated. Sediment samples were collected each two station from Namyang and Sukmoon estuarine reservoirs in August 2013. The fractionation result of sediment phosphorus indicated that Adsorbed-P ($36.7{\pm}8.84%$) and Nonapatite-P ($29.3{\pm}12.50%$) are the two dominant phosphorus groups in the sediments. For sediment release test, eight sets of acrylic chamber (0.3 m $diameter{\times}1m$ high, with 0.15 m sediment depth) were used with aerobic and anaerobic environment. Under anaerobic conditions, rates of $NH_4-N$ release from the sediments were highly variable, with final concentrations of $NH_4-N$ in the overlying water varying from between about 0.69~1.04 in Namyang and 2.58~4.23 mg/L in Sukmoon reservoir. The $NH_4-N$ release was active at the upstream around the confluence of tributary compared to downstream near the embankment. The $PO_4-P$ release was more obvious than $NH_4-N$ in anaerobic condition. The final $PO_4-P$ concentrations were approximately from two-fold to eight-fold higher than initial concentration. In terms of reservoir water quality management, not only tributary pollutants but also sediment nutrient loading is necessary to consider the water quality contribution.

화옹호 유입하천의 수질현황 및 수질항목간의 상관관계

정광욱,윤춘경,장재호,전지홍,Jung Kwang-Wook,Yoon Chun-Gyeong,Jang Jae-Ho,Jeon Ji-Hong 한국농공학회 2006 한국농공학회논문집 Vol.48 No.1

Most projects of tideland reclamation with dike construction produce estuarine reservoirs, which may result in water quality problems due to blocking of natural flow of stream water to the sea. External loadings to the reservoirs through tributaries are major concerns in a concerned water quality management. The water quality of a reservoir is greatly influenced by watershed drainage, and accurate estimation of pollutant is indispensable for in the reservoir management. Concentrations of the microorganisms in stream water and conventional parameters were monitored in the 13 water quality monitoring sites located in a rural watershed of Hwaong estuarine reservoir. The indicator of microorganisms showed strong correlation between them, and regression equations with $R^2\geq0.70$ may be used fur estimating one from other microorganisms. The relationships between water quality parameters obtained in this study may be used to infer one unknown pollutant concentrations from the measured pollutant loadings. This methodology could be applied to other areas where the watershed characteristics are not significantly different from the study area. High concentrations of nitrogen was observed in water quality monitoring sites affected by urban land uses and numbers of livestock in wet day as well as dry day, due to the influent of diffuse sources.

E-beam evaporation법에 의한 ITO 투명박막이 증착된 Plastic Film 제조

정광욱,하기룡,안희준,이동호 한국공업화학회 2003 한국공업화학회 연구논문 초록집 Vol.2003 No.1

자율주행자동차의 실시간 고정밀 위치추정을 위한 파티클필터와 확장칼만필터 융합 위치추정 알고리즘 개발

정광욱,유지환 제어·로봇·시스템학회 2019 제어·로봇·시스템학회 논문지 Vol.25 No.6

In this paper, we fused an extended Kalman filter and a particle filter to accurately locate autonomous vehicles in real time. While previous researchers have widely used extended Kalman filtering for GPS-based localization of dynamic systems, these solutions have suffered from GPS shadows. Meanwhile, since particle filters do not contain any GPS information, the computational delay from the large number of particles limits the localization precision. We propose a complementary method that compensates the problem of each standalone method: we use the output from the particle filter as a sensed position input to the extended Kalman filter after motion prediction and considering the computational time delay. The combined method is free of GPS shadows and localization errors from the computational delay. We tested this method with an autonomous vehicle system at KOREATECH and showed superior performance compared with an extended Kalman filter and the particle-filter-only localization method.

클라우드 시스템에서 해양수치모델 성능 최적화

정광욱,조양기,탁용진 한국해양학회 2022 바다 Vol.27 No.3

최근 클라우드 컴퓨팅 환경에서 해양수치모델 실험을 수행하는 많은 연구가 활발하게 진행되고 있다. 클라우드 컴퓨팅 환경은 대규모 자원이 필요한 해양수치모델을 구현하는데 매우 효과적인 수단이 될 수 있다. 정보처리 기술의 발달로 클라우드 컴퓨팅 시스템은 가상화와 원격 고속 네트워크, 직접 메모리 액세스와 같은 수치모델의 병렬처리에 필요한 다양한 기술과 환경을 제공한다. 이러한 새로운 기능은 클라우드 컴퓨팅 시스템에서 해양수치모델링 실험을 용이하게 한다. 많은 과학자들과 엔지니어들은 해양수치모델 실험에 있어서 가까운 미래에 클라우드 컴퓨팅이 주류가 될 것으로 기대하고 있다. 해양수치모델링을 위한 클라우드 컴퓨팅의 처리성능 분석은 수치모델의 수행 시간과 리소스 활용량을 최소화하는 데 도움이 될 수 있으므로 최적의 시스템을 적용하는 데 필수적이다. 특히 모델 격자 내 다양한 변수들이 다차원 배열 구조로 되어 있기 때문에 대량의 입출력을 처리하는 해양수치모델의구조는 캐시메모리의 효과가 크며, 대량의 자료가 이동하는 통신 특성으로 인해서 네트워크의 속도가 중요하다. 최근에 주요한 컴퓨팅환경으로 자리잡고 있는 클라우드 환경이 이러한 해양수치모델을 수행하기에 적합한지 실험을 통해서 검토할 필요가 있다. 본 연구에서는 상용 클라우드 시스템에서 해양수치모델로 대표적인 Regional Ocean Modeling System (ROMS)와 더불어 다른 해양모델의 클라우드 환경으로 전환에도 도움이 될 수 있게 병렬처리 시스템의 성능을 측정할 수 있는 표준 벤치마킹 소프트웨어 패키지인 High Performance Linpack을 활용하여 초당 부동소수점 연산횟수 처리능력과 및 STREAM 벤치마크를 활용하여 다중 노드들로 구성된 수치모델용 클러스터의 메모리처리성능을 평가하고 비교하였다. 이러한 평가내용은 클라우드 환경에서 해양수치모델을 어떻게 수행할 것인가에 대해 중요한 정보를 제공할 수 있다. 가상화 기반 상용 클라우드에서 얻은 실제 성능 자료와 구성 설정 분석을 통해 가상화 기반 클라우드 시스템에서 해양수치모델의 다양한 격자 크기에 대한 컴퓨터 리소스의 효율성을 평가했다. 본 연구를 통해서 캐시 계층과 용량이 큰 메모리를 사용하는 HPC 클러스터가 ROMS의 성능에 매우 중요하다는 것을 발견했다. 수치모델링의 실행 시간을 줄이기 위해 코어 수를 늘리는 것은 작은 격자 보다 큰 격자 모델에서 더 효과적이다. 이러한 처리 성능 분석 결과는 클라우드 컴퓨팅 시스템에서 해양수치모델을 효율적으로 구축하는 데 중요한 자료로 이용될 것이다.

2P-52 : E-beam evaporation법에 의한 ITO 투명박막이 증착된 Plastic Film 제조

정광욱,하기룡,안희준,이동호 한국공업화학회 2003 한국공업화학회 연구논문 초록집 Vol.2003 No.-

BASINS/HSPF를 이용한 화성유역 오염부하량의 정량적 평가

정광욱,윤춘경,장재호,김형철,Jung, Kwang-Wook,Yoon, Chun-G.,Jang, Jae-Ho,Kim, Hyung-Chul 한국농공학회 2007 한국농공학회논문집 Vol.49 No.2

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to Hwaseong watershed. It was run under BASINS (Better Assessment Science for Integrating Point and Nonpoint Sources) program, and the model was validated using monitoring data of $2002{\sim}2005$. The model efficiency of runoff ranged from good to fair in comparison between simulated and observed data, while it was from very good to poor in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The nonpoint source (NPS) loading for T-N and T-P during the monsoon rainy season (June to September) was about 80% of total NPS loading, and runoff volume was also in a similar range. However, NPS loading for BOD ($55{\sim}60%$) didn't depend on rainfall because BOD was mostly discharged from point source (more than 70%). And water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. BASINS/HSPF was applied to the Hwaseong watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and nonpoint sources in watershed scale.

재처리수 관개후 지표미생물의 농도변화 조사

정광욱,윤춘경,장재호,김형철,전지홍,Jung Kwang-Wook,Yoon Chun-Gyeong,Jang Jae-Ho,Kim Hyung-Chul,Jeon Ji-Hong 한국농공학회 2005 한국농공학회논문집 Vol.47 No.4

A study was performed to examine the effects of reclaimed-water irrigation on microorganism con-centration in ponded-water of paddy rice plots. Several treatments were used and each one was triplicated to evaluate the change of indicator microorganisms (total coliforms (TC), fecal coliforms FC), and E. coli) concentrations in 2003 and 2004 growing seasons. Their concentrations increased significantly right after irrigation, but decreased about $45\%$ in 24 hours. It implies that agricultural activities such as plowing and fertilizing should be practiced one or two days after irrigation considering health-risks. Treatments with UV-disinfected water irrigation demonstrated significantly lower concentrations than others including control plots where natural surface water was irrigated. The monitoring results from actual paddy rice fields and experimental paddy plots showed that concentrations of indicator microorganisms ranged from $10^2\;to\;10^5$ MPN/100mL. A comprehensive assessment of existing agricultural practices and a thorough monitoring in the field as well as treatment-plots are recommended to make more realistic national guidelines more applicable. UV-disinfected water irrigation reduced microorganism concentrations in paddy fields down to below the concentration of conventional paddy rice culture, and is thought to be an effective and feasible measure fur agricultural reuse of secondary effluent.

유역의 토지이용과 오염원 현황이 수질특성에 미치는 영향 분석

정광욱,윤춘경,장재호,김형철 한국육수학회 2006 생태와 환경 Vol.39 No.1

유역 수문 및 수질해석을 위한 HSPF모형 소개

정광욱,Jeong, Gwang-Uk 한국수자원학회 2012 물과 미래(한국수자원학회지) Vol.45 No.12