• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.1-13
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• 2002

Two global optimization methods, the SCE-UA method and the Annealing-simplex (A-S) method for calibrating a daily rainfall-runoff model, a Tank model, was compared with that of the Downhill Simplex method. The performance of the four objective functions, DRMS (daily root mean square), HMLE (heteroscedastic maximum likelihood estimator), ABSERR (mean absolute error), and NS (Nash-Sutcliffe measure), was tested and synthetic data and historical data were used. In synthetic data study. 100% success rates for all objective functions were obtained from the A-S method, and the SCE-UA method was also consistently able to obtain good estimates. The downhill simplex method was unable to escape from local optimum, the worst among the methods, and converged to the true values only when the initial guess was close to the true values. In the historical data study, the A-S method and the SCE-UA method showed consistently good results regardless of objective function. An objective function was developed with combination of DRMS and NS, which putted more weight on the low flows.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.307-312
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• 2000

Fasting heat production (FHP) of growing buffalo calves (Bubalus bubalis) in the body weight range of 76 to 236 kg was determined using open circuit respiration chamber. The details of the chambers, calibration of gas analysers and operation of the systems are described. Animals were fasted for 96 hrs during which only water was provided. FHP was determined during next 24 hrs. The mean oxygen consumed, carbon dioxide and methane produced and urinary N excretion per 24 h was $17.03{\ell}$, $11.70{\ell}$, and $0.12{\ell}$ and 0.35 g respectively. The mean respiratory quotient ranged from 0.68 to 0.71, which indicated that post absorptive stage is reached after 96 hrs in growing buffalo calves previously fed ammoniated straw-based ration. Mean FHP of calves was $331.4kJ/kg\;W^{0.75}$. FHP of calves with range of mean body weights of 167 to 235 kg, although nonsignificant but, was almost 12% higher than of calves having mean body weight of 101 kg. Suitable exponent to body weight to describe FHP of buffalo calves was 0.87.

• Geotechnical Engineering
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• v.12 no.6
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• pp.163-184
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• 1996

In this study, physical and geotechnical properties of the light weight mixed soil( weathered granite soil mixed with small pieces of waste EPS) were analyzed by laboratory experiments to examine its suitability for backfill materials of the reinforced-earth walls. Friction characteristics of geogrid-light weight sized soil were also investigated by performing the pullout tests for two types of geogrids having different flexural rigidity. Also a procedure was proposed to evaluate friction strength between geogrid and light weight miffed soil by using a stress-strain relationship of the orthotropic composite material subjected to both longitudinal and vertical loadings. By the procedure proposed in this study, values of the calibration coefficients ul and uf applicable for the evaluation of friction strengths between two types of geogrids and light weight mixed soils were further presented.

• Journal of Korea Water Resources Association
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• v.50 no.3
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• pp.191-200
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• 2017

A robust parameter set (ROPS) selection framework for an unsteady flow model was developed by combining Pareto optimums obtained by outcomes of model calibration using multi-site observations with the minimax regret approach (MRA). The multi-site calibration problem which is a multi-objective problem was solved by using an aggregation approach which aggregates the weighted criteria related to different sites into one measure, and then performs a large number of individual optimization runs with different weight combinations to obtain Pareto solutions. Roughness parameter structure which can describe the variation of Manning's n with discharges and sub-reaches was proposed and the related coefficients were optimized as model parameters. By applying the MRA which is a decision criterion, the Pareto solutions were ranked based on the obtained regrets related to each Pareto solution, and the top-rated one due to the lowest aggregated regrets of both calibration and validation was determined as the only ROPS. It was found that the determination of variable roughness and the corresponding standardized RMSEs at the two gauging stations varies considerably depending on the combinations of weights on the two sites. This method can provide the robust parameter set for the multi-site calibration problems in hydrologic and hydraulic models.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.29-34
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• 2021

Near infrared reflectance spectroscopy (NIRS) is routinely used for the determination of nutrient components of forages. However, little is known about the impact of sample preparation and wavelength on the accuracy of the calibration to predict minerals. This study was conducted to assess the effect of sample preparation and wavelength of near infrared spectrum for the improvement of calibration and prediction accuracy of Calcium (Ca) and Phosphorus (P) in imported hay using NIRS. The samples were scanned in reflectance in a monochromator instrument (680-2,500 nm). Calibration models (n = 126) were developed using partial least squares regression (PLS) based on cross-validation. The optimum calibrations were selected based on the highest coefficients of determination in cross validation (R2) and the lowest standard error of cross-validation (SECV). The highest R2 and the lowest SECV were obtained using oven-dry grinded sample preparation and 1,100-2,500 nm wavelength. The calibration (R2) and SECV were 0.99 (SECV: 468.6) for Ca and 0.91 (SECV: 224.7) for P in mg/kg DM on a dry weight, respectively. Results of this experiment showed the possibility of NIRS method to predict mineral (Ca and P) concentration of imported hay in Korea for routine analysis method to evaluate the feed value.

• Analytical Science and Technology
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• v.26 no.2
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• pp.125-134
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• 2013

This study was demonstrated to estimate the measurement uncertainty of 23 multiple-component amino acids from beef bone extract by high performance liquid chromatography (HPLC). The sources of measurement uncertainty (i.e. sample weight, final volume, standard weight, purity, standard solution, calibration curve, recovery and repeatability) in associated with the analysis of amino acids were evaluated. The estimation of uncertainty obtained on the GUM (Guide to the expression of uncertainty in measurement) and EURACHEM document with mathematical calculation and statistical analysis. The content of total amino acids from beef bone extract was 36.18 g/100 g and the expanded uncertainty by multiplying coverage factor (k, 2.05~2.36) was 3.81 g/100 g at a 95% confidence level. The major contributors to the measurement uncertainty were identified in the order of recovery and repeatability (25.2%), sample pretreatment (24.5%), calibration-curve (24.0%) and weight of the reference material (10.4%). Therefore, more careful experiments are required in these steps to reduce uncertainties of amino acids analysis with a better personal proficiency improvement.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1053-1059
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• 2003

This study aimed to determine the amount of vitamin C from vegetable & fruit juice by high performance liquid chromatograhy (HPLC). Components for estimation of measurement uncertainty associated with the analysis of vitamin C, such as standard weight, purity, molecular weight, dilution of standard solution, calibration curve, recovery, and precision, were importantly applied. The estimation of uncertainty obtained with systematic and random error based on the GUM (Guide to the expression of uncertainty in measurement) and EURACHEM document with mathematical calculation and statistical analysis. The components, evaluated ty either Type A or Type B methods, were combined to produce an overall value of uncertainty known as the combined standard uncertainty. An expanded uncertainty was obtained by multiplying the combined standard uncertainty with a coverage factor (k) calculated from the effective degree of freedom. The content of vitamin C from vegetable and fruit juice was 27.53 mg/100g and the expanded uncertainty by multiplying by the coverage factor (k, 2.06) was 0.63 mg/100g at a 95% confidence level. It was concluded that the main sources were, in order of recovery and precision, weight and purity of the reference material, dilution of the standard solution, and calibration curve. Careful experiments on other higher uncertainties is further needed in addition to better personal proficiency in sample analysis in terms of accuracy and precision.

• Journal of Environmental Science International
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• v.13 no.2
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• pp.175-180
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• 2004

A prompt gamma-ray neutron activation (PGNA) system was simulated by the Monte Carlo N-Particle transport code (MCNP-4A) to estimate the level at which the scattered photon fluence rate, the absolute efficiency of the HPGe-detector, the volume of the concrete sample and the $^{35}$ /Cl(n, ${\gamma}$) reaction rate in this sample contribute to the count rate in the NaCl concentration measurement. The n- ${\gamma}$ fluence rates at the ST-2 beam tube exit of the HANARO reactor were used as input data, and the GAMMA-X type HPGe detector was modeled to tally 1.1649 MeV ${\gamma}$ -rays emitted from the $^{35}$ Cl(n, ${\gamma}$) reaction in the concrete sample. For three cylindrical concrete samples of 13.8, 46.8 and 157.1 ㎤ volumes, respectively, the relations between the NaCl weight fractions of 0.1, 1, 2 and 5 % in each of the concrete samples and the 1.1 649 MeV pulses created in the HPGe detector model were studied. As a result, it was found that the count rate at the same NaCl concentration nearly depends on the volume of the samples in a simulated condition of the same NaCl concentration samples, and that the linearities of the NaCl concentration calibration curves were reasonable in the narrow range of the NaCl weight fraction.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.395-402
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• 1998

Mori Cortex Radicis, the root bark of mulberry tree, has been used in the treatment of bronchial asthma and other lung diseases in traditional medicine. There was a recent repor t that the water soluble part with molecular weight of above 10,000 has anti-allergic activity. Therefore, we intended to isolate and purify the anti-allergic compound from hot water extract of the Mori Cortex Radicis. Crude extract of Mori Cortex Radicis was prepared by hot-water extraction, and anti-allergic compound was further purified by alcohol precipitation, successive ultrafiltration, anion exchange chromatography and gel filtration chromatography. This compound had homogeneity which was shown by the sharp single peak in HPLC chromatogram (TSK-GEL G400OPW column, RI detector). The molecular weight of the compound was estimated as 23Kda on the basis of calibration curve plotted against protein standards. This compound was identified as complex of sugar, protein and lignin (19.2: 5.9: 72.7), and proteolysis could not decrease the anti-allergic activity but mild delignification decreased the activity remarkably. Therefore, we concluded that the anti-allergic compound of Mori Cortex Radicis was a lignin-carbohydrate complex.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.27-36
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• 2021

A capacitive water sensor was developed to measure the capacitance over a wide part of a substrate using an insulated electrode plate (30 cm × 10 cm) with copper and Teflon attached on either side of the substrate. This study aimed to convert the capacitance output obtained from the condenser-type capacitance sensor into the substrate water content. The quantification experiment was performed by measuring the changes in substrate water weight and capacitance while providing a nutrient solution and by subsequently comparing these values. The substrate water weight and capacitance were measured every 20 to 30 seconds using the sensor and load cell with a software developed specifically for this study. Using a curve-fitting program, the substrate water content was estimated from the output of the capacitance using the water weight and capacitance of the substrate as variables. When the amount of water supplied was increased, the capacitance tended to increase. Coefficient of variation (CV) in capacitance according to the water weight in substrate was greater with the 1.0 kg of water weight, compared with other weights. Thus, the fitting was performed with higher than 1.0 kg, from 1.7 to 6.0 kg of water weight. The correlation coefficient between the capacitance and water weight in substrate was 0.9696. The calibration equation estimated water content from the capacitance, and it was compared with the substrate water weight measured by the load cell.