• Journal of the Korean Statistical Society
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• v.29 no.2
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• pp.201-217
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• 2000

The method of generalized estimating equations (GEE) has become very popular for the analysis of longitudinal data. We extend this work to the use of M-estimators; the resultant regression estimates are robust to heavy tailed errors and to outliers. The proposed method does not require correct specification of the dependence structure between observation, and allows for heterogeneity of the error. However, an estimate of the dependence structure may be incorporated, and if it is correct this guarantees a higher efficiency for the regression estimators. A goodness-of-fit test for checking the adequacy of the assumed M-estimation regression model is also provided. Simulation studies are conducted to show the finite-sample performance of the new methods. The proposed methods are applied to a real-life data set.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.6
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• pp.49-60
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• 2002

This study was conducted to estimate the design flood by the determination of best fitting order of LH-moments of the annual maximum series at six and nine watersheds in Korea and Australia, respectively. Adequacy for flood flow data was confirmed by the tests of independence, homogeneity, and outliers. Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Pareto (GPA), and Generalized Logistic (GLO) distributions were applied to get the best fitting frequency distribution for flood flow data. Theoretical bases of L, L1, L2, L3 and L4-moments were derived to estimate the parameters of 4 distributions. L, L1, L2, L3 and L4-moment ratio diagrams (LH-moments ratio diagram) were developed in this study. GEV distribution for the flood flow data of the applied watersheds was confirmed as the best one among others by the LH-moments ratio diagram and Kolmogorov-Smirnov test. Best fitting order of LH-moments will be derived by the confidence analysis of estimated design flood in the second report of this study.

• Journal of agricultural medicine and community health
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• v.10 no.1
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• pp.5-15
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• 1985

It has been a long tradition in the field of nutrition that the degree of malnutrition in a community used to be estimated by the degree of the adequacy of nutrients consumption in the households. The adequacy of nutrient consumption in the households then used to be applied to estimate the degree of malnutrition of the children. Such a practice is theoretically acceptable in the community where the food sharing within the household is individual serving style such as in European countries. However, the community where the dietary habit in the household is communal such as in Korea, the estimation of single serving portion from household consumption is quite uncertain. Because of such an uncertainty this study is intended to test the validity of the household food consumption level as an indication of nutritional status of the children in the rural farm households in Korea. The date from the household consumption survey in 1982 by the Korean Rural Nutrition Institute has been used for the analysis of food consumption levels of the households. The survey on the nutritional status of children of 127 preschool children from 78 farm households, has been conducted during May 1983. The nutritional status of the children has been directly measured by weight, height, skinfold thickness, haemoglobin, haematocrit and morbidity of influenza and diarrhoea. The analysis has been conducted to distinguish the differences in prevalence of malnutrition of children from the estimated of household consumption and that of from the direct measurement of nutritional status of children. The results show that the degree of malnutrition of the estimated by the household consumption level has not related with the prevalence of malnutrition by the direct measures of nutritional status of the children. Therefore, the validity of household consumption level as an indication of nutrional status in a same household is quite uncertain for the population studied.

• International Journal of Human Ecology
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• v.4 no.2
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• pp.77-87
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• 2003

This paper tried to construct statistical and econometric models on the basis of economic theory in order to discuss the issue of statistical efficiency and unbiasedness including the sample selection bias correcting problem. Comparative analytical tool were one stage Tobit of Maximum Likelihood estimation and Heckman's two-step Tobit of Ordinary Least Squares. The results showed that the adequacy of model for the analysis on demand and choice, we believe that there is no big difference in explanatory variables between the first selection model and the second linear probability model. Since the Lambda, the self- selectivity correction factor, in the Type II Tobit is not statistically significant, there is no self-selectivity in the Type II Tobit model, indicating that Type I Tobit model would give us better explanation in the demand for and choice which is less complicated statistical method rather than type II model.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.344-351
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• 2003

In order to consider the characteristics of nonlinear dynamic responses of seismic isolated bridges reasonably, piers and isolators are modeled as a 2-DOF bilinear system. Then nonlinear time-history earthquake response analysis is accomplished many artificial input ground motions which were generated to reflect the characteristics of earthquakes. Damage probabilities and failure probabilities of each structural elements of the brides are calculated by using Monte-Carlo simulation method. Based on LCC evaluation considering various cost items of direct/indirect damage costs, the optimal design method of seismic isolated bridges is proposed. By using a sensitivity analysis about the design variables and a cost effectiveness evaluation in the viewpoint of LCC, the validity and the adequacy of proposed optimal design method are verified.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.957_958
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• 2009

2DOF is applied to induction moor in order to supply these weak points of PI speed control method in this paper. and proposed method utilize the combination of the voltage model based on stator equivalent model and the current model based on rotor equivalent model, which enables stable estimation of rotor flux. And it also emphasizes the improvement of the control characteristics in low speed region where established schemes have many problems. To prove the propriety of this paper, the various simulations carried out adequacy and stability using Matlab, and at the same time real system is made, so it is proved. As the results of embodying the system, the robust system is realized.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.407-408
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• 2007

Robust pitch estimation is an important study in many areas of speech processing. In voice pathology, diverse statistics extracted form pitch were commonly used to test voice quality. In this study, we compared several established pitch detection algorithms (PDAs) for verification of adequacy of the PDAs. In the database of total pathological voices of 99 and normal voices of 30, an analysis of errors related with pitch detection was evaluated between pathological and normal voices, or among the types of pathological voices such as benign vocal fold lesions; polyp, nodule, and cysts. Consequently, it is required to survey the severity of tested voice in order to obtain accurate pitch estimates.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.175-183
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• 2008

This study reviewed and compared the measured value with the calculated sediment loads value by the existing theory equation, after actually measuring the suspended load, focusing on locality river in Gangwon province. Next, it suggested the application problems of the existing sediment loads calculation equation in case of rivers in Gangwon province, and suggested the proper sediment loads calculation equation to rivers in Gangwon province, after implementing the statistical regression analysis by using the measured data for 5 rears, 2003 ~ 2007.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.196-203
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• 2010

2DOF is applied to induction moor in order to supply these weak points of PI torque control method in this paper. and The proposed method utilize the combination of the voltage model based on stator equivalent model and the current model based on rotor equivalent model, which enables stable estimation of rotor flux. To prove the propriety of this paper, the various simulations carried out adequacy and stability using Matlab, and at the same time real system is made, so it is proved. As the results of embodying the system, the robust system is realized.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.407-416
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• 2009

It is evident that a financial feasibility study based on the economic analysis has been theoretically and practically accepted in the aspect of its adequacy. However, it is not easy to apply in the practical business affairs since there exist some difficulties on the economic analysis and the interpretation of the result because of the difficulty of the estimation of the discount rate. This study aims to suggest a method of the financial feasibility study based on the economic analysis. The results of this study are as follows. First, this study can increase the reliance and adequacy of the economic analysis result by suggesting a method of estimating the discount rate by means of the proxy ${\beta}$ method in the practical way. Second, this study can provide the overall frame of the financial feasibility study based on the economic analysis method (namely, Net Present Value Method internal rate of return, profit index method and payback period method)which use discount rate and cash flow. Third, this study can suggest an practical analysis skill required in each step of the financial feasibility study.