• 한국지구과학회지
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• 제31권7호
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• pp.681-690
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• 2010

블럭으로 주어지는 물리탐사 자료의 역산결과를 시추공 자료와 복합적으로 시뮬레이션하여 암반등급의 분류에 적용하였다. 물리탐사의 역산결과는 해석 대상에 대한 부가적 수준의 정보를 포함하게 되며, 전체 영역에 대한 정보를 제공한다. 반면, 시추공 자료는 해석 대상에 대한 직접적인 정보를 제공하지만, 그 정보의 공간적 범위가 매우 좁아 포인트 자료로써 이용된다. 블럭으로 주어지는 물리탐사 역산결과와 포인트로 주어지는 시추공 자료를 결합하여 크리깅이나 지구통계학적 시뮬레이션을 수행하기 위해서는, 포인트-포인트, 포인트-블럭, 블럭-포인트 간의 공분산 정보가 필요하다. 이 연구에서는 SGeMS에서 제공하는 Bssim 모듈을 이용하여, 역산 블럭과 시추공 포인트간의 복합적 시뮬레이션을 통해 공간적 특성이 다른 자료를 반영하는 다운스케일 된 결과를 얻었고, 이를 선행연구에서 적용한 지구통계학적 역산 결과와 비교하였다. 그 결과, 본 방법에 의한 다운스케일링 기법이 보다 확장가능하고 유연한 적용이 가능한 것으로 판단하였다.

• 응용통계연구
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• 제26권1호
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• pp.93-109
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• 2013

지리통계자료는 관측지점이 지도 상에 점으로 표현되고 그 지점에서만 자료가 관측되는 측정값이다. 이러한 지리통계자료는 매우 다양한 관측망에서부터 얻어진다. 지리통계자료를 분석하고 예측함에 있어서 하나의 자료만 이용하는 것보다는 유사한 패턴을 갖는 다른 관측망에서 얻어지는 여러 자료들을 함께 사용한다면 예측력을 향상시킬 수 있을 것이다. 본 논문에서는 서로 다른 관측망에서 얻은 두 가지의 공간자료를 이용하여 분석 및 예측하고 이를 위해 공간적 연관성을 파악할 수 있는 적절한 계층모형을 구축하였다. 그리고 선형회귀모형에 근간을 둔 크리깅 결과와 계층모형 하에서의 결과를 여러 검증방법을 통해 비교하였다. 이 논문에서는 도시대기측정망에서 측정된 이산화황과 지상기상관측망에서 측정된 풍속자료를 이용하여 계층모형을 구축하고 이산화황만을 이용한 선형모형과 비교하였다. 또한 각 모형에 의한 이산화황 예측지도를 구성하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.399-401
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• 2003

This paper presents a geostatistical contextual classifier for the classification of remote sensing data. To obtain accurate spatial/contextual information, a simple indicator kriging algorithm with local means that allows one to estimate the probability of occurrence of certain classes on the basis of surrounding pixel information is applied. To illustrate the proposed scheme, supervised classification of multi-sensor remote sensing data is carried out. Analysis of the results indicates that the proposed method improved the classification accuracy, compared to the method based on the spectral information only.

• 자원환경지질
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• 제28권2호
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• pp.155-164
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• 1995

The kriging model, one of the geostatistical models, has been used to evaluate the deep-sea manganese nodule deposits until now. The distribution of the manganese nodule deposits estimated by the model shows the smooth surface as well as much difference from the actual distribution. Subsequently, it estimates the deposit distribution roughly in terms of the limited data of surveyed zone. Therefore, this paper presents the interpretation methodology of the deep-sea manganese nodule deposit distribution by using the fractal model to overcome the problems caused by the geostatistical model. Also, the manganese nodule distributions are interpreted by using the manganese nodule data sampled in the GH82-4 zone, west longitude $165^{\circ}40^{\prime}-169^{\circ}00^{\prime}$, and south latitude $0^{\circ}00^{\prime}-2^{\circ}40^{\prime}$ neighboring Nova-Canton Trough in the Pacific Ocean which was surveyed by the Geological Survey of Japan in 1982.

• 호남수학학술지
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• 제26권1호
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• pp.87-103
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• 2004

A practical estimation method for groundwater contaminant concentration is introduced. Using geostatistical techniques and symmetry, experimental variograms show significant improved correlation compared with those from conventional techniques. Numrical experiments are performed using a field data set.

• 한국환경과학회지
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• 제27권7호
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• pp.509-518
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• 2018

Weather is the most influential factor for crop cultivation. Weather information for cultivated areas is necessary for growth and production forecasting of agricultural crops. However, there are limitations in the meteorological observations in cultivated areas because weather equipment is not installed. This study tested methods of predicting the daily mean temperature in onion fields using geostatistical models. Three models were considered: inverse distance weight method, generalized additive model, and Bayesian spatial linear model. Data were collected from the AWS (automatic weather system), ASOS (automated synoptic observing system), and an agricultural weather station between 2013 and 2016. To evaluate the prediction performance, data from AWS and ASOS were used as the modeling data, and data from the agricultural weather station were used as the validation data. It was found that the Bayesian spatial linear regression performed better than other models. Consequently, high-resolution maps of the daily mean temperature of Jeonnam were generated using all observed weather information.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권4호
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• pp.31-44
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• 2014

In the present study, a few of recently developed geostatistical models are comparatively studied. The models are two-point statistics based sequential indicator simulation (SISIM) and generalized coupled Markov chain (GCMC), multi-point statistics single normal equation simulation (SNESIM), and object based model of FLUVSIM (fluvial simulation) that predicts structures of target object from the provided geometric information. Out of the models, SNESIM and FLUVSIM require additional information other than conditioning data such as training map and geometry, respectively, which generally claim demanding additional resources. For the comparative studies, three-dimensional fluvial reservoir model is developed considering the genetic information and the samples, as input data for the models, are acquired by mimicking realistic sampling (i.e. random sampling). For SNESIM and FLUVSIM, additional training map and the geometry data are synthesized based on the same information used for the objective model. For the comparisons of the predictabilities of the models, two different measures are employed. In the first measure, the ensemble probability maps of the models are developed from multiple realizations, which are compared in depth to the objective model. In the second measure, the developed realizations are converted to hydrogeologic properties and the groundwater flow simulation results are compared to that of the objective model. From the comparisons, it is found that the predictability of GCMC outperforms the other models in terms of the first measure. On the other hand, in terms of the second measure, the both predictabilities of GCMC and SNESIM are outstanding out of the considered models. The excellences of GCMC model in the comparisons may attribute to the incorporations of directional non-stationarity and the non-linear prediction structure. From the results, it is concluded that the various geostatistical models need to be comprehensively considered and comparatively analyzed for appropriate characterizations.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.92-96
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• 2001

Although the problem of seawater intrusion at the coastal aquifer was recognized before over one hundred years at the coastal aquifer, much groundwater keep on being salinitized by several reasons such as groundwater exhaustion, coastalline change, and human activities. The horizontal and vertical electrical soundings and geostatistical methods were used to define the local characteristics of saltwater intrusion and to estimate the saltwater interface in the southeastern area of the Pusan City. The 24 points of the Schlumberger vertical electrical soundings(VES) to loom depth and the 2 lines of dipole-dipole horizontal soundings are peformed. The resistivity data have lognormal distributions. The horizontal extents of saline water intrusion were estimated from the inversion of horizontal prospecting data. Lognormal ordinary kriging is used in A-A' resistivity profiles on May and July because the data have stationary models in semivariograms. Lognormal IRF-k kriging is used for the isopleth maps using vertical resistivity data. The 10 ohm-m resistivity line on the isopleth maps of 21m, 30m, 50m, and 70m depth using resisitivity data measured in July is sifted to the east, cpomparing that of the isopleth maps measured in May. The kriged vertical and horizontal resistivity isopleth maps suggested that the geostatistical methods can be used to define the variation of earth resistivity distribution at the saltwater interface.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.352-361
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• 2003

We have evaluated the extent of saltwater intrusion from electrical resistivity distribution in a coastal aquifer system in the southeastern part of Busan, Korea. This aquifer system is divided into four layers according to the hydrogeologic characteristics and the horizontal extent of intruded saltwater is determined at each layer through the geostatistical interpretation of electrical resistivity data. In order to define the statistical structure of electrical resistivity data, variogram analysis is carried out to obtain best generalized covariance models. IRF-k (intrinsic random function of order k) kriging is performed with covariance models to produce the plane of spatial mean resistivities. The kriged estimates are evaluated by cross validation to show a good agreement with the true values and the statistics of cross validation represented low errors for the estimates. In the resistivity contour maps more than 5 m below the surface, we can see a dominant direction of saltwater intrusion beginning from the east side. The area of saltwater intrusion increases with depth. The northeast side has low resistivities less than 5 ohm-m due to the presence of saline water in the depth range of 20 m through 70 m. These results show that the application of geostatistical technique to electrical resistivity data is useful for assessing saltwater intrusion in a coastal aquifer system.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2008년도 공동학술대회
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• pp.63-67
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• 2008

시추공에서 떨어진 지점에서의 암반등급 (RMR)을 물리탐사 자료를 통하여 간접적으로 추정하기 위해, 지구통계학적 복합 역산 기법을 적용하였다. 지금까지 지구통계학적 기법은 두 가지 이상의 자료의 특성을 잘 반영하는 변수를 추정하는데 주로 이용되었으나, 본 연구에서는 역산 기법에 의한 접근 방법을 사용하였다. 시추공에서 확보한 암반 등급 값을 이용하여, 미리 지정된 격자점상에 지구통계학적 시뮬레이션을 수행하여 다수의 추정값을 확보한다. 이 값은 임의의 상관성이 있는 물리탐사 자료와 비교하여 가장 오차가 작은 값을 채택하게 되고, 이와 같은 비교는 모든 격자점에 대해 수행된다. 이러한 절차는 암반등급의 공간적 분포를 준수하면서, 물리탐사 자료와의 비교를 통해 두 자료의 상관성을 최대한 확보한 결과를 얻을 수 있다. 또한 동일한 과정을 다수 수행하여, 추정한 결과의 신뢰도를 분석할 수 있는 정보를 제공할 수 있다.