• Korean Journal of Environmental Agriculture
• /
• v.16 no.3
• /
• pp.233-238
• /
• 1997

WASP5 was applied to evaluate water quality of Bokha stream with 17km of its main stem located in Ichon-city, Kyunggi province in Korea. Boundaries of the stream for the WASP5 were the Jumi bridge, 10 major tributaries and one wastewater treatment system. The stream was divided into 37 segments with about 350m length. The flowrate of the 10 day's average of the stream was obtained from the hydrograph data and the discharge-stage rating curve. Simulated quality constituents included nitrogen, phosphorus, BOD and DO. Monthly records of water quality and loads in 1996 were used for the calibration of parameters of WASP5. Simulation showed high correlations between calculated and observed concentration with monthly runoff ratio in Bokha stream. At downstream boundary, Jumi bridge [Seg.36], similar correlations were appeared. However, simulated concentrations by using annual runoff ratio were somewhat differentiated from those of the observed.

• Journal of Environmental Impact Assessment
• /
• v.20 no.4
• /
• pp.509-521
• /
• 2011

The purpose of this study is to estimate overall reliability and applicability of the watershed modeling for systematic management of point and non-point sources via water quality analysis and prediction of runoff discharge within watershed. Recently, runoff characteristics and pollutant characteristics have been changing in watershed by anomaly climate and urbanization. In this study, the effects of watershed scale were analyzed in runoff and water quality modeling using HSPF. In case of correlation coefficient, its range was from 0.936 to 0.984 in case A(divided - 2 small watersheds). On the other hand, its range was form 0.840 to 0.899 in case B(united - 1 watershed). In case of Nash-Sutcliffe coefficient, its range was from 0.718 to 0.966 in case A. On the other hand, its range was from 0.441 to 0.683 in case B. As a result, it was judged that case A was more accurate than case B. Therefore, runoff and water quality modeling in minimum watershed scale that was provided data for calibration and verification was judged to be favorable in accuracy. If optimal watershed dividing and parameter optimization using PEST in HSPF with more reliable measured data are carried out, more accurate runoff and water quality modeling will be performed.

• Journal of Korea Water Resources Association
• /
• v.41 no.12
• /
• pp.1231-1244
• /
• 2008

The objective of this study is to present a methodology for estimating runoff curve number(CN) using SWAT model which is capable of reflecting watershed heterogeneity such as climate condition, land use, soil type. The proposed CN estimation method is based on the asymptotic CN method and particularly, it uses surface flow data simulated by SWAT. This method has advantages to estimate spatial CN values according to subbasin division and to reflect watershed characteristics because the calibration process has been made by matching the measured and simulated streamflows. Furthermore, the method is not sensitive to rainfall-runoff data since CN estimation is on a daily basis. The SWAT based CN estimation method is applied to Chungju dam watershed. The regression equation of the estimated CN that exponentially decays with the increase of rainfall is presented.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.1
• /
• pp.43-52
• /
• 2017

In this paper, for the first time, the electroanalytical study of Triethylenediamine, TEDA was done on a typically graphene modified carbon paste electrode (Gr/CPE) in pH=10.5 of phosphate buffer solutions (PBS). The surface morphology of the bare and modified electrodes was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electro-oxidation of TEDA was investigated at the surface of modified electrode. The results revealed that the oxidation peak current of TEDA at the surface of Gr/CPE is 2.70 times than that shown at bare-CPE. A linear calibration plot was observed in the range of 1.0 to 202.0 ppm. In this way, the detection limit was found to be 0.18 ppm. The method was then successfully applied to determination of TEDA in aqueous samples obtained from two kinds of activated carbon from the masks of war. On the other hand, density functional theory (DFT) method at B3LYP/6-311++G** level of theory and a conductor-like Polarizable Continuum Model (CPCM) was used to calculate the $pK_a$ values of TEDA. The energies of lowest unoccupied molecular orbital ($E_{LUMO}$) and highest occupied molecular orbital ($E_{HOMO}$), gap energy (${\Delta}E$) and some thermodynamic parameters such as Gibbs free energy of TEDA and its conjugate acid ($HT^+$) were calculated. The results of calculated $pK_a$ were found to be in good agreement with the experimental values.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.4 s.107
• /
• pp.341-350
• /
• 2006

In this paper, a new method for detecting breast cancer is proposed, which utilizes dielectric characteristics of pathological tissues and time delay of back scattered response, and its feasibility was investigated. We have developed a detection algorithm and verified it by numerical simulation and measurement for a prototype system. For a prototype system, we have fabricated experimental model(artificial breast with a cancer) and UWB(ultra-wideband) antenna. The results of the measurement simulation show an excellent detection capability of a cancer tissue. It is found that a good UWB antenna and a good calibration signal are key elements of such detection system. Further study is ongoing to develop a commercial system.

• The KIPS Transactions:PartB
• /
• v.14B no.3 s.113
• /
• pp.163-170
• /
• 2007

In autonomous navigation of a mobile vehicle or a mobile robot, localization calculated from recognizing its environment is most important factor. Generally, we can determine position and pose of a camera equipped mobile vehicle or mobile robot using INS and GPS but, in this case, we must use enough known ground landmark for accurate localization. hi contrast with homography method to calculate position and pose of a camera by only using the relation of two dimensional feature point between two frames, in this paper, we propose a method to calculate the position and the pose of a camera using relation between the location to predict through perspective transform of 3D feature points obtained by overlaying 3D model with previous frame using GPS and INS input and the location of corresponding feature point calculated using KLT tracking method in current frame. For the purpose of the performance evaluation, we use wireless-controlled vehicle mounted CCD camera, GPS and INS, and performed the test to calculate the location and the rotation angle of the camera with the video sequence stream obtained at 15Hz frame rate.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.7
• /
• pp.911-917
• /
• 1999

The sonic nozzle is widely used as reference device for calibrating flowmeters In gas flow measurement and its use requires the Critical Flow Factor(CFF) based on the thermodynamic properties of the gas at the nozzle throat. ISO-9300 provides the calculating method of the factor. But since the CFF from this method show an error over ${\pm}0.5%$ In specific conditions and of ${\pm}0.1{\sim}{\pm}0.2%$ in common Natural Gas(NG) custody transfer condition. this method cannot be applied for gas flow measurement with sonic nozzle. Each research bodies or organizations of the world have joined in order to calculate the CFF more accurately. They have performed these works using their own method and compared the results with each other under the management of ISO. KOGAS have joined those works, because the high-pressure natural gas flow calibration facility of KOGAS will be constructed in late 1999, and then had necessities to calculate a CFF accurately. The calculation method of KOGAS was using the equation of state from AGA-8('94), high accuracy model of ideal gas properties and the solutions of thermodynamic equations. The evaluation results have had a very good consistency within ${\pm}0.05%$ in most NO custody transfer conditions compared to the speed of sound for methane and also shown that the CFF was within ${\pm}0.1%$ compared to the results of other works of the world.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.253-257
• /
• 2010

최근 들어 이상 강우 현상으로 인한 기록적인 집중 강우와 더불어 토지 이용 변화로 인해 탁수의 발생 빈도가 증가하고 있다. 강우 유출로 유입한 탁수는 저수지 내 장기간 체류하면서 하류 하천의 수질 및 수생태계 뿐만 아니라 저수지 내부의 영양단계에도 많은 영향을 준다. 특히, 성층화된 저수지의 경우 높은 영양염류 농도를 포함한 탁수는 밀도류 거동 특성을 보이면서 수평 및 수직 혼합 과정을 거치면서 국부적인 부영양화 현상과 조류의 수화 현상의 원인이 되고 있다. 따라서 대형 저수지의 수질관리에 있어 하천 유입 탁수의 밀도류 해석, 저수지의 수온 성층 구조 변화, 부유입자의 동력학적 해석이 중요한 요소로 부각되어 왔다. 본 연구에서는 소양호를 연구 대상 지역으로 선정하여 2005년과 2007년 수문 사상을 바탕으로 2차원 횡방향 수치 모형을 구축하였다. 수치모형을 통해 수온 성층 구조의 재현성을 확인하였으며, 다양한 탁수 거동 모형을 구축하여 적용성을 평가하였다. 유입수의 SS(Suspended Solid)를 단일 입경으로 가정한 TM-1 모형, SS의 입경분포에 따라 3개의 그룹(SSi)으로 구분한 TM-2 모형, 3개 그룹을 포함하면서 저수지내 탁수 장기화로 인한 탁수 저감 효과를 1차 반응상수로 매개 변수화(유기물 함량($a_0$) ${\times}$ 분해속도(${\lambda}_a$))하여 수정된 지배방정식을 적용한 TM-3 모형을 사용하였다. 각각의 탁수 거동 모형은 2005년과 2007년 수문 조건에서 수온 성층 구조를 잘 재현하였다. TM-1 모형과 TM-2 모형을 비교해보면, 탁수 중심축의 최고 탁도에 대한 예측 성능은 TM-2 모형이 우수한 결과를 나타냈었다. 하지만, 장기 탁수 모의 시 저수지 수중 잔류 SS가 지속적으로 높게 나타나 중층 탁도를 과대평가하는 경향을 보였다. TM-3 모형이 TM-2 모형에 비해 수심별 탁도 분포에 대한 중심축 탁도가 저평가되는 경향을 보였지만 저수지 내 잔류 탁도에 대한 영향 부분에서는 개선된 결과를 나타내었다. 본 연구 결과는 저수지 탁수 밀도류 해석 및 운영 시스템에 활용 될 수 있으며, 선택 취수 설비 등의 수리 구조물의 영향 평가에 활용할 수 있다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.1
• /
• pp.29-34
• /
• 2012

The objective of this study was to rapidly evaluate fatty acids in a collection of millet (Panicum miliaceum subsp. miliaceum) of different origins so that this information could be disseminated to breeders to advance germplasm use and breeding. To develop the calibration equations for rapid and nondestructive evaluation of fatty acid content, near-infrared reflectance spectroscopy (NIRs) spectra (1104-2494 nm) of samples ground into flour ($n$=100) were obtained using a dispersive spectrometer. A modified partial least-squares model was developed to predict each component. For foxtail millet germplasm, our models returned coefficients of determination ($R^2$) of 0.89, 0.89, 0.89, and 0.92 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively. The prediction of the external validation set (n=10) showed significant correlation between references values and NIRs values ($r^2$=0.64, 0.90, 0.79, and 0.89 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively). Standard deviation/standard errors of cross-validation (SD/SECV) values were close to 3 (2.62, 2.40, 1.85, and 2.23 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively). These results indicate that these NIRs equations are functional for the mass screening and rapid quantification of the oleic and total fatty acids characterizing millet germplasm. Among the samples, IT153514 showed an especially high content of fatty acids ($48.14mg\;g^{-1}$), whereas IT123909 had a very low content ($34.44mg\;g^{-1}$).

• Journal of Biosystems Engineering
• /
• v.38 no.1
• /
• pp.48-54
• /
• 2013

Purpose: This study evaluated the feasibility of using a discrete wavelet transform (DWT) method as a preprocessing tool for visible/near-infrared spectroscopy (VIS/NIRS) with a spectroscopic transmittance dataset for predicting the internal quality of cherry tomatoes. Methods: VIS/NIRS was used to acquire transmittance spectrum data, to which a DWT was applied to generate new variables in the wavelet domain, which replaced the original spectral signal for subsequent partial least squares (PLS) regression analysis and prediction modeling. The DWT concept and its importance are described with emphasis on the properties that make the DWT a suitable transform for analyzing spectroscopic data. Results: The $R^2$ values and root mean squared errors (RMSEs) of calibration and prediction models for the firmness, sugar content, and titratable acidity of cherry tomatoes obtained by applying the DWT to a PLS regression with a set of spectra showed more enhanced results than those of each model obtained from raw data and mean normalization preprocessing through PLS regression. Conclusions: The developed DWT-incorporated PLS models using the db5 wavelet base and selected approximation coefficients indicate their feasibility as good preprocessing tools by improving the prediction of firmness and titratable acidity for cherry tomatoes with respect to $R^2$ values and RMSEs.