• Journal of Advanced Navigation Technology
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• v.15 no.3
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• pp.343-348
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• 2011

In this paper, we propose the construction and reconstruction method of satellite radio interferer search system to deal with the keen competition among nations to acquire the limited satellite sources. To construct the satellite interferer search system, whole TLS system construction, part of TLS system construction, and domestic system construction methods are proposed. After that characteristics, advantages, and disadvantages of the system are analyzed when these proposed systems are constructed. In addition, database problems are analyzed in case of the reliability of the operating database, the convergence management between database management systems, and public database service then the solution are proposed.

• Honam Mathematical Journal
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• v.32 no.1
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• pp.157-165
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• 2010

Silver and Whitten proved that every knot in $S^3$ is invertibly concordant to a hyperbolic knot by a series of Nakanishi's construction. We prove that every knot in $S^3$ is invertibly concordant to a nonhyperbolic prime knot by a simple one step satellite construction.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.148-156
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• 2010

For the reasons such as resource development, an interest in the extreme cold regions has been increasing in recent years. Therefore, this study aims to suggest the application methods of satellite images for the construction projects over extreme cold regions. Because extreme cold regions including the Antarctic is generally far and difficult to access, the satellite images are useful to monitor the extreme cold regions. In this study, satellite images can be used in the overall construction process and the application methods presented through the review of the case studies and the related literature.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.398-401
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• 2005

Droughts have been an important factor in disaster management in Korea because she has been grouped into nations of lack of water. Satellite imagery can be applied to droughts monitoring because it can afford periodic data for large area for long time. This study aims to develop a method to analyze droughts in large area using satellite imagery. We estimated evapotranspiration in large area using NDVI data acquired from satellite imagery. For satellite imagery, we dealt with MODIS data operated by NASA. As the result of this study, we improved the usability of satellite imagery, especially in drought analysis.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1417-1430
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• 2015

In this study we were to explore the seasonal variation of water temperature distributions before and after weir construction at Gumi, Chilgok, Gangjung(Goryung), Dalsung in the Nakdong River using Landsat satellite images. Relationship between in-situ water temperature and radiance values of Landsat-5, 7, 8 satellite images showed high correlation. Seasonal variation of water temperature in Nakdong River showed that the fluctuation ranges of water temperature before weir construction were larger than those after weir construction. This indicated that the variation of water temperature is due to the difference of heat storage volume by weir construction and dredging work. In particular, the water temperature after weirs construction in autumn was 4-8 times lower than that before weirs construction. Water temperature after weir construction decreased in spring and summer at the downstream of Gumi weir and Gangjung(Goryung) weir, and the upstream of Dalsung weir. In autumn and winter, the water temperature after weir construction increased in the upstream and downstream of the whole weirs except upstream of Gumi weir. Relationship between water temperature and meteorological elements (air temperature, wind speed, sunshine, radiation) showed high correlation of above 94% in air temperature, and then radiation was high correlation before and after 65%.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.340-343
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• 2004

Since the tide embankment construction started in 1991, the coastal environment in and around the Saemangeum area has undergone changes rapidly, there is a need for monitoring the environmental change in this region. Owing to high temporal and spatial heterogeneity of the coastal ecosystem and processes as well as the expense with traditional filed sampling at discrete locations, satellite remote sensing measurements offer a unique perspective on mapping a large region simultaneously because of the synoptic and repeat coverage and that quantitative algorithms used for estimating constituents' concentration in the coastal environments. Thus, the main objectives of the present study are to analyze the retrieved Suspended Sediment (SS) pattern to predict changes after the commencement of the tide embankment construction work in 1991. This is accomplished with a series of the Landsat TM/ETM+ imagery acquired from 1985-2002 (a total of 18 imageries). Instead of a simple empirical algorithm, we implement an analytical SS algorithm, developed by Ahn et al. (2003), which is especially developed for estimating SS concentration (SSC) in Case-2 waters. The results show that there is a significant change in SS pattern, which is mainly influenced by the tide and tidal height after the construction of the embankment work. As the construction progressed, the distribution pattern of SS has greatly changed, and the rate of SS concentration in the gap area of the dyke of post-construction has significantly increased.

• Proceedings of the KSRS Conference
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• v.1
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• pp.294-296
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• 2006

Recently the development of GIS and spatial information technology is used to construct very detail forest information. In addition, in order to classify forest characteristic, the geographical characteristic information of forest could be very useful for the forest classification, In this study sampling points were arranged to clarify the difference between the orm area and the land forest area. Also, forest feature pattern could be discriminated by using satellite images and SML. This study result should be constructed to efficiency forest management in especially forest area in Jeju Island

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.753-762
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• 2021

Google provides mapping services using satellite imagery, this is widely used for the study. Since about 20 years ago, research and business using drones have been expanding. Pix4D is widely used to create 3D information models using drones. This study compared the distance error by comparing the result of the road construction site with the DSM data of Google Earth and Pix4 D. Through this, we tried to understand the reliability of the result of distance measurement in Google Earth. A DTM result of 3.08 cm/pixel was obtained as a result of matching with 49666 key points for each image. The length and altitude of Pix4D and Google Earth were measured and compared using the obtained PCD. As a result, the average error of the distance based on the data of Pix4D was measured to be 0.68 m, confirming that the error was relatively small. As a result of measuring the altitude of Google Earth and Pix4D and comparing them, it was confirmed that the maximum error was 83.214m, which was measured using satellite images, but the error was quite large and there was inaccuracy. Through this, it was confirmed that there are difficulties in analyzing and acquiring data at road construction sites using Google Earth, and the result was obtained that point cloud data using drones is necessary.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.339-346
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• 2013

This study analyzes the application possibilities of the satellite-derived precipitation to water resources field. Precipitation observed by ground gauges and climate prediction center morphing method (CMORPH) which is global scale precipitation estimated by National Oceanic and Atmospheric Administration Climate Prediction Center (NOAA CPC) using satellite images are compared to evaluate the quality of precipitation estimated from satellite images. Precipitation data from 10-years (2002 to 2011) is applied. The correlation coefficient of 1-day cumulative precipitation is 0.87, but the 1-year precipitation is 4 to 5 times different. The variability of root mean square error (RMSE) become smaller as temporal resolution lower. On the results for the watershed scale, the precipitation from gauges and CMORPH shows better agreement as the watershed become larger.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.46-53
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• 2010

In this paper, we explained status and development trend of GNSS (Global Navigation Satellite System): GPS (Global Satellite System) of US, GLONASS (Global Navigation Satellite System) of Russia, Galileo of EU, Beidou/Compass of China, and QZSS (Quasi-Zenith Satellite System) of Japan). System construction and operation status of five GNSS systems were summarized. In addition, development plan and modernization of these systems were explained.