• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.1
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• pp.4052-4063
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• 1976

The observation and Studies on the two stations in the Ansung river are included that were justified types of Bed-materials movement and were estimated loads volume of sediment applied by sediment rating curve and/or drivel formulars according to both stream conditions. The results of evaluation for above purpose are given as follows 1) Drived formulas for sediment computation in accordance with river situations are given as follows. -Suspended load Yu-chun Ts=135H4.55 Hye-hwa Ts=454H3.71 -Bed load Yu-chun Tb=75.4H191 Hye-hwa Tb=134.5H1.82 2) Annual volume of surface erosion in the catchment area were obtained at yu-chun of 0.236mm Hye-hwa of 0.200mm and mean depth of 0.22mm 3) The Bed-materials movement with water depth were represented that ripple is bellow than 0.067 meter at yu-chun and bellow than 0.096 meter at Hye-hwa stream, Dunes is 0.067-0.22 at yu-chun and 0.096-0.23 at Hye-hwa, Transition is 0.22-0.46 at yu-chun and 0.23-0.58 at Hye-hwa and Antidunes is higher than 0.46 at yu-chun and 0.58 of water depth at Hye-hwa stream

• Journal of Korea Water Resources Association
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• v.37 no.2
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• pp.155-161
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• 2004

The purpose of this study is to verify LSPIV technique. Verification was made using moving cart with known velocity. The difference of velocity values obtained using these methods are within 5％, which means that LSPIV can be used in the field with reasonable accuracy After verification, LSPIV was applied to the river. The Neungwon stream and the Gonjiam stream, tributaries of the Kyungan stream, were selected as the test sites for application. The results of the test application were compared with those obtained by 3-D electromagnetic current meter and electron-wave surface velocity meter. Results show that the velocity values obtained using LSPIV coincide well with those obtained using conventional devices with maximum difference of 8％.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.581-589
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• 2013

Surface Image Velocimetry(SIV) is an instrument to measure water surface velocity by using image processing techniques. Since SIV is a non-contact type measurement method, it is very effective and useful to measure water surface velocity for steep mountainous streams, such as streams in Jeju island. In the present study, a surface imaging velocimetry system was used to calculate the flow rate for flood event due to a typhoon. At the same time, two types of electromagnetic surface velocimetries (electromagnetic surface current meter and Kalesto) were used to observe flow velocities and compare the accuracies of each instrument. The comparison showed that for velocity distributions root mean square error(RMSE) was 0.33 and R-squared was 0.72. For discharge measurements, root mean square error(RMSE) reached 6.04 and R-squared did 0.92. It means that surface image velocimetry could be used as an alternative method for electromagnetic surface velocimetries in measuring flood discharge.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.5
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• pp.29-43
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• 2008

As the containership has been large-sized, it is important to analyze the social feasibility for the dredging the water-depth of Busan port. We tries to do an exploratory study to analyze the needs of the core port user group by using the survey methodology. We did the survey for the ocean carriers, terminal operating companies, ship pilots respectively. Collected data was analyzed by frequency and cross tabulation method. Result suggests that the Busan North Port should be dredged to the 16 meter depth and Busan New Port should be dredged to the 17 meter depth. And the priority of the depth dredging is ranked as Gamman pier, Sinsundae pier, New Port and Jasungdae pier.

• The Korean Journal of Malacology
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• v.20 no.1
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• pp.45-53
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• 2004

This study have conducted to calibrate the productivities on the mussel (Mytilus galloprovincialis) cultures in Jinhae Bay. Annual water temperature, salinity and dissolved oxygen have varied to 7.2-$25.9^{\circ}C$, 32.9-34.0 psu, 7.9-8.7 mg/l, respectively. In April, the smallest size of spat, 3.3 mm in shell length, have recruited, and 82.5 mm have recorded to the maximum. In summer, variations of growing up between individuals showed both shell length and weights at same cohort. Annual production at 2 m, 5 m, 8 m depth calculated to 10.91, 10.85 and 9.19 gWWt/ind./yr, respectively. Mussel cultivated in the upper part of the water column (two meter depth) were significantly longer and heavier than those in lower part (eight meter depth). After the recruitment, monthly production showed gradual increment at all positions during summer. As results, annual production of mussel cultivated seemed to be controlled by conditions of growing up in summer. Based on the productivities calculated to this study, the total annual production of the mussel cultivated in Jinhae Bay have estimated about 196 ton/ha/yr.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.47-52
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• 2017

In general industry, TFM(turbine flow meters) as measuring instruments having high reliability are widely used in the trade of petroleum and in the measurement of tap water and hot water. The TFM is performed calibration for using in the field and is mainly calibrated at room temperature. Since accuracy of TFM depends on Reynolds number of fluid, TFM is calibrated at same Reynolds number by changing flow rate. Furthermore, the TFM using a fluid of high temperature should have considered for other factors such as the thermal expansion of the parts and characteristics change is unknown changes in the turbine flow meter accordingly. In this paper, two turbine flowmeter are experimentally studied about characteristics change using the facilities which can change fluid temperature from 6 degree celsius to 90 degree celsius. As a result, the turbine flow meter can be calibrated to minimize the error characteristic at a similar temperature and the actual temperature.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1405-1409
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• 2010

최근 우리나라는 물 부족 국가로서 물의 효율적 관리 필요성 증대, 기후변화에 따른 가뭄 홍수 피해 증가 등으로 신뢰성 있는 수문자료구축이 필요성이 요구되고 있다. 그 중 유량측정 분야는 모든 수자원 계획과 관리의 근간이 되는 분야로 그 중요성 또한 간과 할 수 없는 부분이다. 현재 우리나라에서는 한국건설기술연구원 산하 유량조사사업단에 의해 유량측정 주요지점에 자동유량측정 시설을 설치하고 이를 운영함으로써 각 지점의 특성에 따라 적절한 방식을 채택하여 이동시간차방식 초음파 유속계(UVM, Ultrasonic Velocity Meter)와 도플러방식 초음파유속계(ADVM, Acoustic Doppler Velocity Meter)를 설치하면서 향후 수문계측 분야 선진화를 위한 기초자료를 제공하고 있다. 하지만 실시간 무인화 계측시스템에 의해 제공되는 자료가 양질의 자료임을 보장할 수 없는 현실이기 때문에 측정된 기초자료의 필터링을 통한 자료의 질적 개선이 필요하다. 따라서 본 연구에서는 기존에 전산분야의 필터링 방법으로 널리 알려져 있는 LPF(Lowpass Filter)와 KF(Kalman Filter)를 이용하여 자동유량측정 자료의 필터링 방법으로 활용하고, 그 적용성을 검토하였다. 본 연구를 통해 기존 유량자료의 문제점을 개선하고 효율적인 유량조사를 위한 기초자료 확보 방법으로 활용될 수 있을 것으로 기대된다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.33-38
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• 2003

Turbidity meter calibrations were conducted using bottom sediment and suspended material collected with a vertical array of sediment traps at the coastal water off Gaduk Island. Compared to the bottom sediment comprising sand fraction of approximately 6％, trapped suspended material was composed entirely of silt and clay fractions and showed a tendency to get finer as elevation from the sea-bed increases. Slope parameter of linear regression due to bottom sediment was of minimum value and values of those due to suspended material increased gradually as the height of sediment trap increases (i.e., sediment size decreases). This result shows that turbidity meter calibration using bottom sediment can cause an overestimation error in the calculation of suspended sediment concentration and that the error can reach up to 25% in case of this study. Therefore, it is suggested that the use of a corrected calibration curve based on grain size distribution of suspended material instead of bottom sediment may reduce the measurement error of suspended sediment concentration.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.389-400
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• 2019

Level meters are non-invasively capable of measuring the level of the medium, and a growing variety of level meters are being used in the industry in connection with safety and maintenance. The level meter can be measured according to various kinds of medium such as solid medium such as coal, flour, rice and liquid medium such as water and petroleum. In order to reduce the error depending on the medium, the measurement using the Doppler Effect can compensate the measurement error, However, the number of signal processing steps is increased, the operation speed is further increased, the hardware complexity increases, and a high cost structure is required. In this paper, we propose a method to improve the signal processing operation structure of the remote measurement level meter to reduce the amount of computation and the resource usage of the required FPGA.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.279-290
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• 2004

Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.