• 대한화학회지
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• 제40권1호
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• pp.20-27
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• 1996

분광학적 실험 자료들로부터 안정하고 정확한 위치에너지를 역으로 얻어내는 방법에 대하여 연구하였다. 이러한 역과정 방법은 비선형 역과정 문제에서 야기되는 불안정성을 위치에너지가 유연하게 연속적이라는 제한 조건을 사용하여 최적의 해를 얻어내는 Tikhonov의 규칙화에 기초를 두고 있다. 이 방법의 장점은 특정한 형태의 위치에너지 변수를 맞추는 보통의 방법과는 달리 위치에너지를 분자간 거리의 연속함수로 다루었다. 이 방법을 실험적으로 얻은 Ar-Ar계의 분광학적 자료에 적용하여 전 구간에서 정확한 위치에너지를 찾아가는 것을 보여주었고, Morse나 RKR 방법으로 얻은 위치에너지의 부정확한 먼거리 인력 부분을 보정할 수 있음을 보여주었다.

• Communications for Statistical Applications and Methods
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• 제17권6호
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• pp.845-852
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• 2010

The outcomes of counts commonly occur in the area of disease mapping for mortality rates or disease rates. A Poisson distribution is usually assumed as a model of disease rates in conjunction with a gamma prior. The small area typically refers to a small geographical area or demographic group for which very little information is available from the sample surveys. Under this situation the model-based estimation is very popular, in which the auxiliary variables from various administrative sources are used. The empirical Bayes estimator under Poissongamma model has been considered with its accuracy measures. An accuracy measure using a bootstrap samples adjust the underestimation incurred by the posterior variance as an estimator of true mean squared error. We explain the suggested method through a practical dataset of hitters in baseball games. We also perform a Monte Carlo study to compare the accuracy measures of mean squared error.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권3호
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• pp.27-41
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• 2017

This study dealt with the characteristics and the interrelations of hydrogeological parameters such as hydraulic conductivity, dispersivity and effective porosity of unconsolidated sediments for providing the basic data necessary for the planning of the management and preservation of groundwater quality in the Nakdong River Delta of Busan City, Korea. Groundwater quality in this area has been deteriorated due to seawater intrusion, agricultural fertilizer and pesticide, industrial wastewater, and contaminated river water. The physical properties (grain size distribution, sediment type, sorting) and aquifer parameters (hydraulic conductivity, effective porosity, longitudinal dispersivity) were determined from grain size analysis, laboratory permeability test and column tracer test. Among 36 samples, there were 18 Sand (S), 7 Gravelly Sand (gS), 5 Silty Sand (zS), 5 Muddy Sand (mS), and 1 Sandy Silt (sZ). Hydraulic conductivity was determined through a falling head test, and ranged from $9.2{\times}10^{-5}$ to $2.9{\times}10^{-2}cm/sec$ (0.08 to 25.6 m/day). From breakthrough curves, dispersivity was calculated to be 0.35~3.92 cm. Also, effective porosity and average linear velocity were obtained through the column tracer test, and their values were 0.04~0.46 and 1.06E-04~6.49E-02 cm/sec, respectively. Statistical methods were used to understand the interrelations among aquifer parameters of hydraulic conductivity, effective porosity and dispersivity. The relation between dispersivity and hydraulic conductivity or effective porosity considered the sample length, because dispersivity was affected by experimental scale. The relations between dispersivity and hydraulic conductivity or effective porosity were all in inverse proportion for all long and short samples. The reason was because dispersivity was in inverse proportion to the groundwater velocity in case of steady hydrodynamic dispersion coefficient, and groundwater velocity was in proportion to the hydraulic conductivity or effective porosity. This study also elucidated that longitudinal dispersivity was dependent on the scale of column tracer test, and all hydrogeological parameters were low to high values due to the sand quantity of sediments. It is expected that the hydrogeological parameter data of sediments will be very useful for the planning of groundwater management and preservation in the Nakdong River Delta of Busan City, Korea.