• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.515-523
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• 2018

In order to obtain consistent change detection result for multi-temporal satellite images, preprocessing must be performed. In particular, the preprocessing related to the spectral values can be performed by the radiometric normalization, and relative radiometric normalization is generally utilized. However, most relative radiometric normalization methods assume a linear relationship between the two images, and nonlinear spectral characteristics such as phenological differences are not considered. Therefore, this study proposes a relative radiometric normalization which assumes nonlinear relationships that can perform compositive normalization of radiometric and phenological characteristics. The proposed method selects the subject and reference images, and then extracts the radiometric control set samples through the no-change method. In addition, spectral indexes as well as pixel values are extracted in order to consider sufficient information, and modeling of nonlinear relationships is performed through multilayer perceptron. Finally, the proposed method is compared with the conventional relative radiometric normalization methods, which shows that the proposed method is visually and quantitatively superior.

• Korean Journal of Remote Sensing
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• v.36 no.5_2
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• pp.917-927
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• 2020

The Ministry of Land, Infrastructure and Transport of Korea is developing a CAS 500-1/2 satellite capable of photographing a GSD 0.5 m level image, and is developing a technology to utilize this. Therefore, this study attempted to develop a geospatial feature extraction technique aimed at automation as a technique for utilizing CAS 500-1/2 satellite images. KOMPSAT-3A satellite images that are expected to be most similar to CAS 500-1/2 were used for research and the possibility of automation of geospatial feature extraction was analyzed through relative radiometric normalization. For this purpose, the parameters and thresholds were applied equally to the reference images and relative radiometric normalized images, and the geospatial feature were extracted. The qualitative analysis was conducted on whether the extracted geospatial feature is extracted in a similar form from the reference image and relative radiometric normalized image. It was also intended to analyze the possibility of automation of geospatial feature extraction by quantitative analysis of whether the classification accuracy satisfies the target accuracy of 90% or more set in this study. As a result, it was confirmed that shape of geospatial feature extracted from reference image and relative radiometric normalized image were similar, and the classification accuracy analysis results showed that both satisfies the target accuracy of 90% or more. Therefore, it is believed that automation will be possible when extracting spatial objects through relative radiometric normalization.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.999-1011
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• 2021

In spatio-temporal fusion aiming at predicting images with both high spatial and temporal resolutionsfrom multi-sensor images, the radiometric inconsistency between input multi-sensor images may affect prediction performance. This study investigates the effect of radiometric correction, which compensate different spectral responses of multi-sensor satellite images, on the spatio-temporal fusion results. The effect of relative radiometric correction of input images was quantitatively analyzed through the case studies using Sentinel-2, PlanetScope, and RapidEye images obtained from two croplands. Prediction performance was improved when radiometrically corrected multi-sensor images were used asinput. In particular, the improvement in prediction performance wassubstantial when the correlation between input images was relatively low. Prediction performance could be improved by transforming multi-sensor images with different spectral responses into images with similar spectral responses and high correlation. These results indicate that radiometric correction is required to improve prediction performance in spatio-temporal fusion of multi-sensor satellite images with low correlation.

• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.137-140
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• 1992

실내 바닥슬래브의 휨진동에 의한 음향방사문제에 대하여 유한요소법을 적용하여 검토하였다. 단순한 형상의 판이 휨진동하여 자유공간에 음을 방사하는 문제에 대해서는 이론적인 해를 구할 수 있으나, 임의형상의 판이 휨진동하여 실내에 음을 방사하는 문제에 대해서는 검토되지 않았다. 따라서 본 연구에서는 이와같은 문제를 단순화한 해석법으로서 먼저 유한요소법을 이용하여 판의 휨진동에 대한 고유모드의 상대변위를 구하고, 다음 상대변위를 진동속도로 변환한 결과를 입력조건으로 하여 유한요소법에 의한 3차원 음장해석을 하였다. 그 결과 실내 바닥슬래브의 휨진동에 의한 음향방사파워는 슬래브의 진동모드, 실내음향모드 및 벽흡음율 등의 조건에 따라 크게 변화된다는 것을 확인하였다.

• 전기의세계
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• v.41 no.3
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• pp.17-25
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• 1992

원적외선 방사특성은 방사체로부터 적외선이 방사되면 상대물체에 닿고 흡수되어 원자나 분자를 여기하여 발열하는 현상이기 때문에 방사체의 적외선 방사특성과 피가열체의 적외선 흡수특성과의 정합성을 고려하여야 한다. 또한 적외선 방사특성은 온도와 방사체의 표면상태 및 조성에 크게 의존하기 때문에 용도에 따른 선택이 중요시 되기도 한다. 현재는 적외선을 열에너지의 전파형태로서만 생각하는 것이 아니라 상온에 가까운 저온에 있어서도 미약한 에너지가 어떻게 생리, 생체적, 바이오 테크널러지(Biotechnology)면에서 효과가 있는지가 가장 관심을 끌고 있다. 그러므로 적외선 방사의 특성을 정확하게 평가하고 보다 깊이있는 연구를 하여 과학적 사실로 입증할 수 있는 노력이 이루어져야 한다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.05a
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• pp.411-412
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• 2011

• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.163-170
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• 2006

The argument concerning the choice of effect measure for epidemiologic data or clinic data has been renewed. But the relationships among effect measures can be confusing if effect measures are expressed by conventional mathematical functions alone. In this article, risk difference(RD), relative risk(RR), and odds ratios(OR) for binary data are presented by radar diagram instead of mathematical functions and the relationships among them are showed using radar diagram. This radar diagram is offered flexible conceptual tool to understand effect measures, DR, RR, and OR for binary data.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.11-17
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• 1981

The study was carried out to investigate the distribution and composition of community of Stewartia koreana in Temple Huibang and Mt. Sogri. The results obtained were as follows: 1. Within the forest floor cover species of the Temple Huibang forest, higher importance value were observed as Calamagrostis arundinacea. Sasa borealis. Lindera erythrocarpa and Lindera obtusiloba 2. In the forest floor cover species of Mt. Sogri forest, higher importance value were observed as Sasa borealis and Acer pseudo-sieboldianum var. koreanum 3. Within the floor cover species under Stewartia koreana forest, higher importance value were observed as Sasa borealis. Acer pseudo- sieboldianum var. koreanum and Calamagrostis arundinacea 4. Under shrub layer of Stewartia koreana stands, 73% of Sasa borealis and Calamagrostis arundinacea in Temple Huibang and 93% of Sasa borealis in Mt. Sogri were counted respectively as dominant species. Therefore, it might be necessary to control such dominant undergrowing species for natural reproduction of Stewartia koreana 5. In the Temple Huibang sites, by 700m Sasa borealis and 800m Calamagrostis arundinacea were grown as dominant species.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.636-644
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• 1999

Experimental and simulation results are presented on the Aperture-Coupled microstrip patch antennal with U-shaped slot. Experiment and simulation results include impedance bandwidth, copolar and crosspolar-pattern characteristics and gain measurements. Simulation results show the advantages of U-slotted patch antenna comparing with the normal patch antenna. More than 35% impedance bandwidth is obtained with reasonably restricted cross-polar radiation pattern. The U-slotted radiation element fed by aperture-coupling method can be more easily extended to array structure, compared with that fed by coaxial cable.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.525-526
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• 2016