• 한국물환경학회지
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• 제34권2호
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• pp.202-209
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• 2018

The purpose of this study was to analyze the correlation between the effluent of a sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. Flow and water quality data, such as BOD, COD, SS, T-N, and T-P data, for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS, and T-P were correlated positively with the river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluents and downstream streams, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between the river flow rate and the water quality factors (COD, SS, TP) was high at river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.493-493
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• 2018

The purpose of this study was to analyze the correlation between the effluent of the sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. The flow and water quality such as BOD, COD, SS, T-N, and T-P data for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS and T-P were correlated positively with river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluent and downstream stream, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between river flow rate and water quality factors (COD, SS, TP) was high for river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.264-271
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• 1999

The present experimental study is aimed to investigate the flow characteristics of the high-speed flow field within hot-water pump by PIV(Particle Image Velocimetry). As multi-point simultaneous velocity acquisition, 2-D PIV system based upon the two-frame gray-level cross correlation method is adopted using PC frame-grabber and simple video system. Gated image intensifier CCD Camera to cope with illumination problem is arranged for accurate PIV measurement of high-speed complex flow. The velocity vector distribution, velocity profile, and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a pump.

• 설비공학논문집
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• 제15권2호
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• pp.152-158
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• 2003

Titration method is one of the widely used methods for the concentration measurement of absorbent ammonia/water. However, this method is inconvenient because the solution should be extracted for the measurement. Moreover, significant error can be introduced by the evaporation of ammonia during the sampling and measuring procedure. In this study a reliable in-line concentration measurement method was proposed. To prove the validity of the concept, a measuring apparatus was designed, built, and tested with water. It is found that the location of flow inlet and exit is important in the measurement accuracy. The flow inlet and exit located in the middle of the test cell showed the best result. By the error analysis, it is expected that the ammonia concentration can be measured within the error of $\pm$0.18% assuming the error of 0.1 K in temperature measurement and 0.1 g in weight measurement.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.86-87
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• 2005

• 대한기계학회논문집B
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• 제39권7호
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• pp.549-555
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• 2015

적외선 카메라를 이용한 입자추적유속계(IR-PTV)를 활용하여 물-공기 분리유동 시 계면속도를 측정하는 기법을 개발하였다. $3-5{\mu}m$ 파장대의 적외선은 물에 대해 $20{\mu}m$ 이하의 침투 깊이를 가지므로 입자추적유속계 기법에 활용 시 물-공기 계면 근처에 존재하는 추적입자들의 이동속도를 선택적으로 측정할 수 있다. IR-PTV 기법의 측정 정확도를 검증하기 위하여 물에 잘 뜨는 스티로폼 입자를 이용하여 $10^{\circ}$ 기울어진 경사면에서 공기-물 분리유동 시 계면속도를 측정하여 비교한 결과 5% 이내의 오차를 보이면서 잘 일치하였다. 개발한 기법을 이용하여 획득한 실험결과로부터 공기 속도가 증가함에 따라 계면속도가 비례하여 증가하는 것을 관찰하였으며 이는 계면전단력의 증가에 의한 것으로 해석된다.

• Journal of Platform Technology
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• 제11권2호
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• pp.66-75
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• 2023

첨단장비 도입 및 기술의 발전으로 수문조사 측정 기술은 향상되었으나 여전히 수문조사 시 많은 인력과 시간이 필요하며, 업무 규모와 범위에 비해 투입되는 인력은 매우 제한적이다. 또한, 자동유량 측정시설이 운영되고 있지만 현장 조건의 제한되기 때문에 전국으로 확대하기가 어렵다. 따라서 수문조사를 위해 측정 기술 자체보다는 운영 인프라 및 환경 개선이 필요하다. 또한 유량조사 측면에서 수위-유량 관계식의 정확도 재고와 업무 효율성 증진을 위해 실시간 수위 정보를 이용한 조사 스케줄링이 필요하다. 따라서 본 논문에서는 국내 수문조사 관련 연구 파악 및 수문조사의 경제성과 효율성 증대를 위하여 Open API 기반의 실시간 수위 정보를 활용한 수문조사 스케줄링 시스템을 구현하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.107-107
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• 1999

Direct-contact condensation experiments of atmospheric steam and steam/air mixture on subcooled water flowing co-currently in a rectangular channel are carried out uszng an infrared thermal camera system to develop a temperature measurement method. The inframetrics Model 760 Infrared Thermal Imaging Radiometer is used for the measurement of the temperature field of the water film for various flow conditions. The local heat transfer coefficient is calculated using the bulk temperature gradient along the (low direction. It is also found that the temperature profiles can be used to understand the interfacial condensation heat transfer characteristics according to the flow conditions such as noncondensable gas effects, inclination effect, and flow rates.

• 한국농공학회논문집
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• 제50권2호
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• pp.65-71
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• 2008

A monsoon season monitoring data from June to September, 2005 of a small forested watershed located at the upstream of the North Han River system in Korea was conducted to analyze the flow variations, the NPS pollutant concentrations, and the pollution load characteristics with respect to sampling frequencies. During the 4-month period, 1,423 mm or 79.2% of annual rainfall(1,797 mm) were occurred and more than 77%, 54% and 68% of annual T-N, $NO_3$-N and T-P loads discharged. Flow rate was continuously measured with automatic velocity and water level meters and 58 water quality samples were taken and analyzed. It was analyzed that the flow volume by random measurement varied very widely and ranged from 79% to 218% of that of continuous measurement. It was recommended that flow measurement of small forested watersheds should be continuously measured with automated flow meters to precisely measure flow rates. Flow-weighted mean concentrations of T-N, $NO_3$-N and T-P during the period were 2.114 mg/L, 0.836 mg/L, and 0.136 mg/L, respectively. T-N, $NO_3$-N and T-P loads were sensitive to the number of samples. And it was analyzed that in order to measure the pollution load within the error of 10% to the true load, the rate of sampling frequency should be higher than 89.7% of the sample numbers that were required to compute the true pollution load. If it is compared to selected foreign research results, about 10 water samples for each rainfall event were needed to compute the pollution load within 10% error. It is unlikely in Korea and recommended that thorough NPS pollution monitoring studies are required to develop the standard monitoring procedures for reliable NPS pollution quantification.

• 한국물환경학회지
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• 제23권3호
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• pp.385-390
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• 2007

Reliable flow measurement for dry season is very important to set up the in-stream flow exactly and total maximum daily load control program in the basin. Especially, in the points which tidal current effects are dominant because reliability of the low measurement decrease. The reliable measuring methods are needed. In this study, we analysis the water surface elevation difference of water surface elevation. Quantity relationship to consider tidal currents in these regions. It is known that tidal current effects from Nakdong river barrage are dominant in Samrangjin measuring station. We developed multiple regression equation with water surface elevation, quantity, and difference of water surface elevation and compared these results water measured rating curve. All of these regression equation including linear regression equation and log regression equation fits better measured data them existing water surface elevation quantity line and Among three equations, the log regression equation is best to represent the measured the rating curve in Samrangjin point. The log regression equation is useful method to obtain the quantity in the regions which tidal currents are dominant.