• Membrane and Water Treatment
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• 제10권1호
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• pp.99-104
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• 2019

In Korea, nonpoint pollutants have a significant effect on rivers' water quality, and they are discharged in very different ways depending on rainfall events. Therefore, preparing an optimal countermeasure against nonpoint pollutants requires much monitoring. The present study was conducted to help prepare a method for installing an automatic nonpoint pollutant measurement system for the cost-effective monitoring of the effect of nonpoint pollutants on rivers. In the present study, monitoring was performed at six sites of a river passing through an urban area with a basin area of $454.3km^2$. The results showed that monitoring could be performed for a relatively long time interval in the upstream and downstream regions, which are mainly comprised of forests, regardless of the rainfall amount. On the contrary, in the urban region, the monitoring had to be performed at a relatively short time interval each time when the rainfall intensity changed. This was because the flow rate was significantly dependent on the rainfall's intensity. The appropriate sites for installing an automatic measurement system were found to be a site before entering the urban region, a site after passing through the urban region, and the end of a river where the effects of nonpoint pollutant sources can be well-decided. The analysis also showed that the monitoring time should be longer for the rainfall events of a higher rainfall class and for the sites closer to the river end. This is because the rainfall runoff has a longer effect on the river. However, the effect of nonpoint pollutant sources was not significantly different between the upstream and the downstream in the cases of rainfall events over 100 mm.

• 한국물환경학회지
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• 제23권4호
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• pp.429-433
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• 2007

Many researchers have made a study of NPS unit-loads and the scientific evaluation method which need for formulating and enforcing a Total Maximum Daily Load (TMDL) management system and modifying a pollutant discharge loadings function. Some showed the event mean concentration (EMC) on single land-use. For the most parts, as the results showed on multiple land-uses, those cannot be used for NPS unit-loads calculation. NPS runoff shows various phenomena depending on rainfall monitoring data, therefore sampling methods and frequency for NPS monitoring must be different from the general monitoring for water quality trend assessment.

• 한국물환경학회지
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• 제23권6호
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• pp.985-992
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• 2007

There are about 40,000 chemicals used in Korea and 300 new types of chemicals are added to the list every year, influencing quality of air, soil and water. Water quality standards that serve as the basis for water quality management have been proved inefficient and insufficient compared to those of advanced countries. This study aims to improve the existing water quality standards. Most importantly, the water quality standards need to take into account not only protection of human health but also aquatic resources. To that end, water quality criteria need to be set by monitoring each watershed every year and conducting risk assessment. Criteria for human health are set at $10^{-6}$ cancer risk level, and for aquatic life at conservative level, adopting the methodology of the U.S. and Australia, respectively. After carrying out technical and economic feasibility studies, more conservative criteria will be used to decide final water quality standards. The development of this system to establish integrated water quality standards for both human health and aquatic resources protection is urgently needed.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.36-41
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• 2008

Cooling tower is an important equipment of the cooling systems for large buildings like factory and department store. Water used for cooling in cooling tower is reused continuously. If the water is polluted, corrosion and scale can happen at equipments and pipes. In order to prevent this problem, it is necessary to control the water quality using chemicals. To control the water quality, an automatic control system is designed, fabricated, and experimented. The control system is based on an imbedded microcontroller. Relays are used for power driving, an LCD and LED for display, and RS485 for remote data acquisition. Monitoring program is also developed for easy man-machine interface and extraction of data stored in the imbedded processor and EEPROM. The control system calculates amounts of chemicals necessary using sensor data and injects the chemicals into the cooling tower on proper time. The developed water quality control system is expected to reduce cost of maintenance and extend the lifetime of the cooling systems with low cost.

• 한국방재학회 논문집
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• 제2권4호
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• pp.69-75
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• 2002

본 연구에서는 하천수질자료를 현장계측하고 무선으로 실시간 전송하여, GIS 상에서 자료를 분석하여 하천수질의 이상을 신속, 정확하게 파악하여 하천의 수질관리를 효율적으로 관리할 수 있는 GIS에 기반한 하천수질 관리시스템을 개발하였다. 시스템을 성능을 테스트할 목적으로 한강의 제1지류인 탄천을 시범유역으로 선정하여 개발된 시스템을 테스트하였다. 하천관리시스템은 크게 GPS 수신기가 탑재된 무선 실시간 계측시스템, 서버컴퓨터, GIS 시스템의 세 부분으로 나뉘어지며 각각의 시스템을 통합, 연계하여 최종 시스템을 개발하였다. 개발된 하천관리시스템을 시험유역에 적용한 결과 탄천 수질자료의 측정이 실시간으로 이루어짐과 동시에 서버컴퓨터에 저장되는 자료를 GIS 시스템 상에서 즉시 표출하고 가공할 있게 됨으로서 하천 수질을 실시간으로 관리할 수 있는 가능성을 제고하였으며 수질오염확산예측 및 수질방재등의 목적으로 활용할 수 있는 가능성을 확인하였다.

• 한국전기전자재료학회논문지
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• 제32권6호
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• pp.472-476
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• 2019

We have proposed a novel planar lightwave circuit (PLC) optical sensor to monitor the contamination in a flow-cell where water is continuously supplied through a water quality measurement system. We designed a PLC chip with a V-shape waveguide and the simulated its function as a sensor for monitoring contamination in a flow-cell using a numerical the FDTD (finite-difference time-domain) analysis. A novel cross type of waveguide was introduced to make the PLC chip of the V-shaped waveguide. The fabricated PLC was cut into the cross waveguide. A change in the optical propagation loss of the PLC sensor was observed after immersing the PLC sensor into city water. It was determined that the propagation loss of the PLC sensor was 3 dB at a wavelength of $1.55{\mu}m$ in the city water for 15 days.

• 디지털융복합연구
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• 제17권10호
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• pp.1-12
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• 2019

본 연구에서는 물벼룩 감시장치를 이용하여 생태독성 기준 1 TU(Toxic Unit)에 해당하는 물벼룩 감시장치의 TI(Toxic Index)값을 설정하고 NOEC와 $EC_{50}$에서 물벼룩 감시장치를 운영하였을 때 적절히 경보가 발령되어 실시간 생태독성 평가가 가능한 지 타진하였다. 연구목적을 위해 국 내외 관련 자료를 조사하여 선행연구를 하였고 인공 하천수를 대상으로 먹는물 수질감시항목에서 권고하는 59개 유해물질 중 6개(As, Hg, Cr, Diazinon, Dioxane, Phenol) 물질을 채택하여 지수식과 유수식 그리고 정도관리 시험을 실시하였다. 시험결과 NOEC 유수식 시험에서 Diazinon을 제외한 다른 물질들은 TI가 양호단계로 나타났고 $EC_{50}$ Spiking test에서 1 TU 이상과 1 TU 이하를 구분하여 TI는 TU에 상응하게 경보를 발령했다. 본 연구결과는 생태독성관리제도의 보완점을 생각하고 효율적인 관리체계로의 전환을 요구하는 하나의 메시지가 된다.

• 한국물환경학회지
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• 제35권1호
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• pp.55-63
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• 2019

The Four Major Rivers Restoration Project started in 2009 and completed in early 2013 is a large-scale inter-ministry SOC project investing ₩22.2 $10^{12}$ and one of the Project's objectives was to enhance the water-quality grade through recovering the river eco-system and environment. The average concentration and probability distribution of water-quality constituents at given and selected sampling sites are very significant elements for analyzing and controlling the water-quality of rivers or reservoirs effectively. Average concentration can be estimated by point estimator, distribution function of water-quality constituents or Bootstrap method, in which the distribution function estimated with more data in case of insufficient dataset, is applied. Ipo and Gangcheon water-quality monitoring stations in South Han River were selected to compare and analyze the variation of concentration before and after Ipo and Gangcheon Weirs construction, using the whole 4-year's data, from 2005 to 2008 and from 2014 to 2017. Water-quality constituents such as BOD and COD relating to oxygen demanding wastes and TP and Chlorophyll-a relating to the process of nutrient enrichment called eutrophication were also selected. The guidelines for water-quality control and management after weir construction including evaluation of water-quality constituents' variations can be presented by this paper.

• 한국정보통신학회논문지
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• 제12권5호
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• pp.930-936
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• 2008

유전자 알고리즘을 이용하여 바이오센서의 활동량을 측정하는 CMOS 이미지 모니터링 시스템을 개발하였다. 수중의 물벼룩, 물고기와 같은 살아있는 대부분 생물체는 수질을 모니터링하는 바이오센서로 자주 사용된다. 이미지 센서에 의해 바이오센서의 활동량의 측정은 이미지를 얻는 방법에 따라 다르게 측정됨으로 매우 어렵다. 제안된 모니터링 시스템은 유전자 알고리즘을 사용하여 바이오센서 활동량을 최적으로 측정할 수 있다. 그리고 이 시스템은 FPGA로 되어 있어 가격과 성능 면에서 우수한 작은 하드웨어로 구현된다.

• Agribusiness and Information Management
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• 제9권1호
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• pp.18-22
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• 2017

It takes lots of time and labor if a worker have to measure the water quality at a certain but designated time every day in an un-automated aqua farm. In addition, if the equipment is soaked in the sea water consistently, it will be contaminated by diverse floating matters and barnacles, and it often becomes mal-functional within 2~3 months. Therefore, we need to develop a system with which the sensed data could be checked in real time and operated automatically, while preventing the contamination of the sensor, a crucial component for water quality measuring equipment, as much as possible, and increasing the replacement cycle. We have developed a non-cleaning water quality measuring equipment and its software which are used in the fishery household of offshore aqua farms. By providing the workers with a mobile application which has a function of monitoring the water quality in real time, they can check the situation directly without going to the fishery household.