• Journal of Wetlands Research
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• v.11 no.2
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• pp.107-121
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• 2009

Many rainfall-runoff models have been used for the flood forecasting. However, the determination of rainfall-runoff model parameters is very difficult. In this study, we investigated the efficiency of flood forecasting models by studying the optimization techniques for parameter calibration of SFM, Tank, and SSARR models. We analyzed the correlations between parameters in optimization techniques, then classified the parameters into parameter groups. For this we applied the sequential calibration method through the sensitivity analysis. As the results of the analysis, the parameter groups clibration method showed better result for peak flow and clibtation time.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.475-483
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• 2011

Quantitative estimate of manganese nodules based on the operation of a free fall grab (FFG) needs to be corrected because of its less retrieval ability. Previously, the correction parameter of the nodule abundance collected by FFG was calculated based on the image analysis of the photos of bottom sediment in the northern sector of the nodule exploration area of Korea in the NE equatorial Pacific. However, nodules in the southern sector are commonly covered by sediment, which may prevent the use of the correction parameter estimated by photographic techniques. In this study, we attempted dual nodule sampling at the same location by different equipments (i.e. box corer (BC) and FFG) to examine the previous correction parameter of nodule abundance for FFG operation. During the exploration cruises in 2007 to 2009, Mn-nodules were collected from 40 stations both by BC and FFG in the southern sector. The correlation analysis between BC and FFG operations revealed that the BC collected nodules 1.43 times larger than FFG. Our result suggests that the correction parameter of 1.43 can be applied for collection of FFG data to estimate Mn-nodule distribution in the southern sector. The obtained parameter is similar to the previous parameter (1.42~1.45) calculated by the image analysis method, indicating an usefulness of new correction parameter suggested by this study.

• Journal of Korea Multimedia Society
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• v.3 no.5
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• pp.495-505
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• 2000

In this paper, we propose an efficient auto-fitting system for digital hearing-aids which automatically adjusts the fitting parameters according to the auditory characteristics of hearing handicapped person. The fitting parameters are extracted from audiogram of hearing handicapped and are applied to digital hearing-aid purposed GM3036 chip. The characteristics of each parameter are compared with those from theoretical 2cc graph. The purposed system has applied to 50 patients and their satisfaction ratios show to the very high. As results, it shows effectiveness of proposed system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.21-32
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• 2008

Flood forecasting is a very important tool as one of nonstructural measures for reduction of flood damages in life and property and its accuracy is also an important factor. However, when we apply the Storage Function Model(SFM) which is mainly used for the flood forecasting system in Korea, the determination of the parameters is very important but it is difficult. So, the parameters have been calibrated by using an empirical formulas and judgement of hydrologist. Hence, in this study we perform the sensitivity analysis to understand the parameter characteristics and establish the ranges of parameters of the SFM. Also we do the parameter calibration by using the optimization techniques and objective functions, and evaluate their performances. Especially, we suggest a method to determine proper parameters by using a objective function which can be obtained from flood events. So, we use the suggested method for parameter estimation and compare the estimated parameters with the previously reported parameters. As a result of the application, the estimated parameters by the suggested method showed better than them from the previously reported parameters.

• Journal of Korea Water Resources Association
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• v.50 no.4
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• pp.241-252
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• 2017

This study aims to evaluate applicability of both online and offline parameter calibration techniques on rainfall-runoff modeling using a conceptual lumped hydrologic model. To achieve the goal, the storage function model was selected and then two different automatic calibration techniques: SCE-UA (offline method) and particle filter (online method) were applied to calibrate the optimal parameter sets for 9 rainfall events in the Cheoncheon catchment, upper area of the Yongdam multi-purpose dam. In order to assess reproducibility of hydrographs from the parameter sets of both techniques, the observed discharge of each event was divided into low flow (below average flow) and high flow (over average flow). The results show that the particle filter method, updating the parameters in real-time, provides more stable reproducibility than the SCE-UA method regardless of low and high flow. The optimal parameters estimated by SCE-UA are very sensitive to the selected objective functions used in this study: RMSE and HMLE. In particular, the parameter sets from RMSE and HMLE demonstrate superior goodness-of-fit values for high flow and low flow periods, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.958-964
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• 2010

Histogram Equalization(HE) is one of the well known methods for contrast enhancement. but, it did not applied directly due to side effects such as significant change in brightness or washed out appearance. Many conventional method try to overcome this problem but they did not guarantee various image or depend on user define parameter. In this paper, an Adaptive histogram Compensated Histogram Equalization(ACHE) is proposed for contrast enhancement. ACHE has a parameter that based on median of input image. Histogram of input image is compensated according to parameter. And then finally compensated histogram is equalized. Experimental results show that proposed method suppresses side effects such as detail loss or washed out appearance. Moreover, parameter calculated automatically with low computation complexity. As a result, it could applies FPD directly.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.116-119
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• 2009

HSPF is a comprehensive, continuous, lumped parameter, watershed-scale model that simulates the movement of water, sediment, and a wide range of water quality constituents on pervious and impervious surfaces, in soil profiles, and within streams and well-mixed reservoirs. The hydrologic calibration of HSPF is performed manually using the decision-support software Expert System for the Calibration of HSPF (HSPEXP). The initial values for the HSPF hydrologic parameters were estimated based on guidance from BASINS Technical Note 6. Initial parameter values were adjusted for the study watershed during the calibration period within the recommended ranges for the parameters.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.657-664
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• 1999

This paper introduced the basic theory of LRCS(Linear Reservoir and Channel System) rainfall runoff model proposed by Korean researchers(Lee and Lee, 1995), and discussed the change of model output according to objective functions in sensitivity analysis and calibration process of model. It proposed "hat" matrix and affluence measures for affluence analysis of parameters in calibration, and investigated relationship between change of model output according to error propagation in parameter estimation, and sensitivity of model output according to variance of model output and change of parameters. Accuracy of parameter estimates was known by analysis of sensitivity coefficient, diagonal element $h_i$ and $D_i$._i$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.397-400
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• 2010

The changing light condition of scene cause the luminance fluctuation of the captured image sequences. this artifact is called flicker, and would be easily recognized as visually unstable fluctuation. As the flicker degrades the performance of extracting useful information from image sequences, such as motion information or segmentation, it should be correction and linear flicker model. The algorithm model the flicker effects as a linear system with gain and offset parameter and estimates gain parameter with Gamma correction. The flicker reduction is performed by applying these parameters inversely th the ordinal sequences. To show the performance, we test out algorithm th the ground-truth sequences with the artificially added luminance fluctuation and real sequence with object motion.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.665-674
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• 1999

This paper confirmed the applicability of model to Korean rivers through the calibration and sensitivity analysis of LRCS rainfall runoff model for 18 storm events of Songriweon station in Nakdong river system, and achieved that LS and WLS were better than LAD by model fitting results. Diagonal element of "hat" matrix and affluence measures were used by analysis of parameter estimates, and parameter IL was the most important parameter in model output. By the results of error propagation according to parameter error, parameters IL, TP, F1 were affected by error propagation, and this is measure of sensitivity for the model output. This paper confirmed the relationship of calibration and sensitivity analysis of model through analysis of sensitivity coefficient, diagonal element $h_i$ and $D_i$._i$.