• 대한지리학회지
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• 제48권1호
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• pp.37-55
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• 2013

기존의 푄 관련 선행연구에서는 크게 영서 지방에서 푄(Foehn)이 두드러지게 나타난다고 하였다. 그러나 영서 지방의 어디에서 두드러지게 나타나며 어떠한 분포양상을 보이는지에 대해서는 연구된 바가 없다. 본 연구는 영서 지방 중 홍천 지역을 대상으로 푄 발생 시의 일최고기온분포도 작성을 통해 국지적인 규모에서 푄의 빈도와 강도에 어떠한 차이가 나는지를 파악하고자 하였다. 연구대상기간은 2003년부터 2012년까지 봄에서 초여름(3~6월)이다. 기온과 해발고도를 변수로 한 공동크리깅(CoKriging)기법을 사용하였을 경우 푄 발생일의 일최고기온분포도 작성에 있어서 보다 높은 정확도를 나타내었다. 일최고기온분포도의 작성을 통해 푄은 홍천 전 지역에서 나타나는 것이 아니며 일부 지역에서만 나타나는 것을 확인하였다. 특히 홍천강 하류 지역에서 푄이 빈번하며 강도 또한 강함을 파악하였다. 홍천 지역 주민들의 푄 인식 정도에 대하여도 조사해 보았다. 봄철에 고온 건조함을 느끼지만 그것이 푄에 의한 것인지 인식은 하지 못하고 있었다. 본 연구의 국지기후 규모에서 푄을 분석하는 절차와 기법은 지역기후 이해와 연구분야에 기여 할 수 있을 것이며 특히 근래에 봄철부터 여름철에 두드러지게 나타나는 고온, 여름철 폭염, 봄철 농작물 생육 등과 관련하여 응용하여 적용할 수 있을 것이라 생각한다.

• 환경영향평가
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• 제19권6호
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• pp.647-656
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• 2010

As the $CO_2$ from buildings take up approximately 25% of the total $CO_2$ emission, the need for regulating and managing this emission is urgently required. Thus this study recognizes $CO_2$ emission status for diverse purposes and suggests accurate interpolation method for visualizing $CO_2$ emission as the basic data for regulating and managing $CO_2$ emission by applying IDW, Spline, and Kringing method. Results showed that Gaussian Function application among the Kriging methods had the highest accuracy in its estimations, with 3.049 with RMSE standards. This could be used as the basic data when visualizing $CO_2$ emission status, which is a necessity for many local and federal governments that are to regulate and manage $CO_2$ emission. This study shows that the interpolation is very appropriative method in recognizing $CO_2$ emission characteristics for regional climate change measures.

• 한국환경과학회지
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• 제22권2호
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• pp.151-161
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• 2013

The assessment of personal exposure is a critical component in population-based epidemiologic studies of air pollution. This study was conducted to apply and compare the four exposure estimation methods of individual-level to air pollution concentration in a cohort including 2,283 subjects in Gwangyang, Korea. Individual-level exposure of air pollution were estimated using multiple approaches, including average across all monitors, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. The mean concentrations of $PM_{10}$, $NO_2$, $SO_2$, CO, $O_3$ by four exposure estimation methods were slightly different but not significantly different from each other. Cross-validation showed that kriging was more accurate than other exposure estimation methods because kriging has probably predicted individual exposure levels equivalent to residential locations after estimating the parameters of a model according to the spatial surface of air pollution concentration. These data support that spatial interpolation methods may provide better estimates than selecting the value from the nearest monitor and averaging across values from all monitors by reflecting spatial attributes of air pollution on personal level.

• Geomechanics and Engineering
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• 제23권3호
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• pp.261-273
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• 2020

This paper presents an efficient method utilizing user-defined computer functional codes to determine the reliability of an embankment slope with spatially varying soil properties in real time. The soils' mechanical properties varied with the soil layers that had different degrees of compaction and moisture content levels. The Latin Hypercube Sampling (LHS) for the degree of compaction and Kriging simulation of moisture content variation were adopted and programmed to predict their spatial distributions, respectively, that were subsequently used to characterize the spatial distribution of the soil shear strengths. The shear strength parameters were then integrated into the Geostudio command file to determine the safety factor of the embankment slope. An explicit metamodal for the performance function, using the Kriging method, was established and coded to efficiently compute the failure probability of slope with varying moisture contents. Sensitivity analysis showed that the proposed method significantly reduced the computational time compared to Monte Carlo simulation. About 300 times LHS Geostudio computations were needed to optimize precision and efficiency in determining the failure probability. The results also revealed that an embankment slope is prone to high failure risk if the degree of compaction is low and the moisture content is high.

• 한국대기환경학회지
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• 제25권4호
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• pp.339-346
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• 2009

The objectives of this study were to introduce spatial interpolation methods which have been applied in recent papers, to apply three methods (nearest monitor, inverse distance weighting, kriging) to domestic data (Ulsan cohort) as an example of estimating the personal exposure levels. We predicted the personal exposure estimates of 2,102 participants in Ulsan cohort using spatial interpolation methods based on information of their residential address. We found that there was a similar tendency among the estimates of each method. The correlation coefficients between predictions from pairs of interpolation methods (except for the correlation coefficient between nearest montitor and kriging of CO and $SO_2$) were generally high (r=0.84 to 0.96). Even if there are some limitations such as location and density of monitoring station, spatial interpolation methods can reflect spatial aspects of air pollutant and spatial heterogeneity in individual level so that they provide more accurate estimates than monitor data alone. But they may still result in misclassification of exposure. To minimize misclassification for better estimates, we need to consider individual characteristics such as daily activity pattern.

• Journal of Information Processing Systems
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• 제15권2호
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• pp.386-398
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• 2019

The transmission capacity of transmission lines is affected by environmental parameters such as ambient temperature, wind speed, wind direction and so on. The environmental parameters can be measured by the installed measuring devices. However, it is impossible to install the environmental measuring devices throughout the line, especially considering economic cost of power grid. Taking into account the limited number of measuring devices and the distribution characteristics of environment parameters and transmission lines, this paper first studies the environmental parameter estimating method of inverse distance weighted interpolation and ordinary Kriging interpolation. Dynamic thermal rating of transmission lines based on IEEE standard and CIGRE standard thermal equivalent equation is researched and the key parameters that affect the load capacity of overhead lines is identified. Finally, the distributed thermal rating of transmission line is realized by using the data obtained from China meteorological data network. The cost of the environmental measurement device is reduced, and the accuracy of dynamic rating is improved.

• 한국기계가공학회지
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• 제17권6호
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• pp.75-82
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• 2018

This study suggests an optimal design process of an LMU, which is installed on the top side of offshore structures. The LMU is consist of EB(elastomeric bearing) and steel plate, and supports the vertical loads of offshore structures and assists its stable installation. The structural design requirement of the LMU is related to its stiffness. This study utilizes the finite element analysis to predict the stiffness. The stiffness of the EB depends on the size of the bearing. Thus, the design variables in this study are defined as the thickness, the width and the number of plates. Since the LMU has different loads for different locations, its stiffness should be designed differently. The multiobjective function is introduced to attain the target stiffness. In this process, the metamodel using the kriging interpolation method is adopted to replace the true stiffness.

• 한국지반공학회논문집
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• 제28권11호
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• pp.5-16
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• 2012

일부 지점에서 수행된 시추조사결과를 이용하여 미조사구간의 지층분포를 추정하는 경우, 예측하고자 하는 변수들의 공간적인 분포 추정뿐만 아니라 추정결과에 수반되는 불확실성을 정량적으로 평가하는 것도 중요하다. 본 논문에서는 송도신도시 풍화토층 출현심도 추정결과의 국부적 불확실성을 지시자 방법을 이용하여 평가하였다. 지시자 방법을 이용하여 작성한 각 위치에서의 조건부 누적분포함수의 평균을 이용하여 송도신도시 풍화토층 출현심도의 공간적 분포를 추정하였다. 또한, 조건부 누적분포함수와 손실함수를 이용하여 송도신도시의 최적 풍화토층 출현심도를 결정하였다. 본 논문에서 이용한 손실함수를 고려할 수 있는 설계방법이 지반공학분야에도 잘 적용될 수 있음을 확인하였다.

• Spatial Information Research
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• 제20권5호
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• pp.1-13
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• 2012

본 연구는 그동안 이산화탄소의 유동 방향 연구에서 지적된 지상관측자료의 시 공간적 제약성을 극복하고자, 최초의 온실가스 측정 전용 위성인 GOSAT을 활용하여 동북아시아 지역의 계절별 이산화탄소의 유동 방향을 평가하고자 하였다. 이를 위해 크리깅 분석을 적용하여 결측값을 보완하고, 이방성 베리오그램을 통해 전체적인 이산화탄소의 유동 방향을 결정하였다. 그 결과 동북아시아의 이산화탄소 공간적 분포 양상은 위도대에 일치하는 변화추세를 확인할 수 있었으며, 계절별 유동성은 봄, 가을, 겨울의 경우 남동쪽 및 동쪽으로 유동되는 이산화탄소가 주를 이루어 나타났으며, 여름에 경우 북쪽 및 북동쪽으로 이동하는 흐름이 나타났다. 이러한 결과는 동북아시아 지역에서 나타나는 계절풍과 유사한 흐름으로 주로 서에서 동으로 이동되는 경우가 주를 이루고 있음을 알 수 있으며, 이는 중국에서 배출된 이산화탄소가 한반도와 일본까지 영향을 미치고 있음을 확인할 수 있다. 그러나 이산화탄소의 유동은 인위적 배출원과 식생의 호흡, 해양의 배출과 흡수 등의 다양한 요인과 결부되어 달라지기 때문에 이산화탄소 유동에 개입되는 다양한 변수와 상관성을 평가하는 후속연구가 필요할 것으로 사료된다.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.160-166
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• 2024

The inversion of radiation field distribution is of great significance in the decommissioning sites of nuclear facilities. However, the radiation fields often contain multiple mixtures of radionuclides, making the inversion extremely difficult and posing a huge challenge. Many radiation field reconstruction methods, such as Kriging algorithm and neural network, can not solve this problem perfectly. To address this issue, this paper proposes an optimized inverse distance weighted (IDW) interpolation algorithm for reconstructing the gamma radiation field. The algorithm corrects the difference between the experimental and simulated scenarios, and the data is preprocessed with normalization to improve accuracy. The experiment involves setting up gamma radiation fields of three Co-60 radioactive sources and verifying them by using the optimized IDW algorithm. The results show that the mean absolute percentage error (MAPE) of the reconstruction result obtained by using the optimized IDW algorithm is 16.0%, which is significantly better than the results obtained by using the Kriging method. Importantly, the optimized IDW algorithm is suitable for radiation scenarios with multiple radioactive sources, providing an effective method for obtaining radiation field distribution in nuclear facility decommissioning engineering.