• 한국해양학회지
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• v.29 no.4
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• pp.383-391
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• 1994

Sea surface height geoidal undulation, and gravity anomaly derived from satellite altimeter measurements are described. Assuming mean sea surface height (MSSH) as geoidal undulation, MSSH was converted to gravity anomaly. the result shows that the gravity anomaly derived from satellite altimeter data can be mapped to an accuracy of the surface ship gravity measurements. The data used for the conversion is the two-year mean sea surface height obtained from GEOSAT Exact Repeat Mission. The conversion was carried out using fast Fourier transform with plane approximation. In this process, the so called remove-restore method was employed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.323-334
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• 2011

In this study, we performed the residual geoid modeling using the FFT and LSC methods in context of application of R-R (Remove and Restore) technique as a general technique for gravimetric geoid model in order to propose the effective way of geoid determination in Korea. For this, a number of data compiled for residual geoid modeling by the multi-band spherical FFT method with Stoke's formula and LSC method as known as statistical method. The geometric geoidal heights obtained from 503 GPS/Levelling data were used for inducing the various elements and proper computation process which should be considered for improving the accuracy of residual geoid modeling. Finally, we statistically compared the results of residual geoid heights between FFT and LSC methods and reviewed then the proper way of residual geoid modeling to the region of Korea. As the results of comparison, LSC method is not suitable for residual geoid modeling in Korea due to the noise and lack of gravity observations and the effects of local characteristics, while FFT method by applying Stokes' integral with proper cap size and modified kernel which provides the better accuracy of residual geoid heights up to 10 cm more than those of LSC method.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2016.09a
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• pp.25-28
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• 2016

Recently, because of the weather forecasts through the low-resolution data has been limited, the demand of the high-resolution data is sharply increasing. Therefore, in this study, we restore the ultra-high resolution synthetic precipitation and temperature data for 2000-2014 due to small-scale topographic effect using the QPM (Quantitative Precipitation Model)/QTM (Quantitative Temperature Model). First, we reproduce the detailed precipitation and temperature data with 1km resolution using the distribution of Automatic Weather System (AWS) data and Automatic Synoptic Observation System (ASOS) data, which is about 10km resolution with irregular grid over South Korea. Also, we recover the precipitation and temperature data with 1km resolution using the MERRA reanalysis data over North Korea, because there are insufficient observation data. The precipitation and temperature from restored current climate reflect more detailed topographic effect than irregular AWS/ASOS data and MERRA reanalysis data over the Korean peninsula. Based on this analysis, more detailed prospect of regional climate is investigated.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.35-37
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• 2010

To construct precision geoid model, the gravity data having equal distribution and quality is necessary. In previous study, however, the geoid model has low precision since the biased distributed gravity data and some unverified data has been used and the gap between land and ocean exists. Now, the airborne and land gravity data was collected by various survey and the ship-borne gravity data and altimeter data has been achieved. Therefore, the precision geoid model development would be possible. And the GPS/Leveling data obtained by NGII could be used for construction of hybrid geoid in Korea. In this study, the procedure of geoid construction based on airborne, land, ship-borne and altimeter data using Remove-Restore technique will be explained. And the verification of gravimetric geoid and hybrid geoid would be introduced.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.255-260
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• 2012

Currently, the management system of wastewater treatment facility has magnified due to the stringent regulations for the protection of the environment. However, wastewater treatment system is insufficient in wastewater quality monitoring technology in specialized. Above all it aim one-to-one data transmission instead of one-to-n data transmission through sensor and network. And then, it lack compatibility toward communication system between different. Mainly it has observed detecting system of manual system. In this paper, we studied protocol technology about efficient data transmission between sensor and integration interface of water quality detecting interface for automated sensor network integration interface in water restoration facility. Therefore, we proved the possibility of efficient data transmission from communication system of different type through monitoring implementation of sensor network integration interface.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.467-476
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• 2017

In this paper, we analyze Generalized Feistel Network(GFN) Type I, Type II, Type III that round function use SP update function, secret S-box and $k{\times}k$ MDS matirx. In this case an attacker has no advantage about S-box. For each type of GFN, we analyze and restore secret S-box in 9, 6, 6 round using the basis of integral cryptanalysis with chosen plaintext attack. Also we restore secret S-box in 16 round of GFN Type I with chosen ciphertext attack. In conclusion, we need $2^{2m}$ data complexity and ${\frac{2^{3m}}{32k}},{\frac{2^{3m}}{24k}},{\frac{2^{3m}}{36k}}$ time complexity to restore m bit secret S-box in GFN Type I, Type II, Type III.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.102-110
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• 2000

This paper presents an algorithm of local map building for autonomous robot navigation using LASER range finder information. We develop a model of sensor output for a LASER range finder, and obtain an output data of the LASER range finder for a given environment. From the output data, a local map is obtained through the following procedures: (1) filtering of output data to remove noisy and unnecessary data, (2) comparison of filtered data with the original data to restore useful data, (3) thickening of the map obtained from the restored data, and (4) skeletonizing of the thickened map to get a final local map. Through some simulation studies, a map is obtained from the LASER range finder information for a given indoor environment, and is compared with the environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.486-490
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• 2005

The web is used widely and the users of the majority are depending to get the information on web, the necessity of the data management by web is increasing. The sudden system failure frequently occurs from network environment, we must protect data from this danger. In this paper, we present web based data management method, which is composed of two type backup and restoration. This method support data management through web browser and provides systematic, efficient and stable data management on web.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.10
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• pp.3406-3418
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• 2022

Reversible data hiding is an algorithm that has ability to extract the secret data and to restore the marked image to its original version after data extracting. However, some previous schemes offered the low image quality of marked images. To solve this shortcoming, a new reversible data hiding scheme based on pixel value ordering and edge detection mechanism is proposed. In our proposed scheme, the edge image is constructed to divide all pixels into the smooth regions and rough regions. Then, the pixels in the smooth regions are separated into non overlapping blocks. Then, by taking advantages of the high correlation of current pixels and their adjacent pixels in the smooth regions, PVO algorithm is applied for embedding secret data to maintain the minimum distortion. The experimental results showed that our proposed scheme obtained the larger embedding capacity. Moreover, the greater image quality of marked images are achieved by the proposed scheme than that other previous schemes while the high EC is embedded.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.28-35
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• 2020

This study aims to analyze restoration techniques of traditional garden sites targeted Korean, Chinese, Japanese palace garden. Restoration was divided into the restore foundation and restore individual elements depending on the residual state of the actual garden features. And derived characteristics that should be considered by conservation techniques. The results are as follows; First, the Wanfo Pavilion Area in Beihai Park where the foundation and foundation stones were restored based on the relevant literature and comparative analysis. The Archaeological Site in Gwanbuk-ri, Buyeo restored only the remaining structures of the ponds, waterways and large buildings among the areas where the excavation was completed. The Second Daigokuden Garden in Heijokyo Palace restored building sites and foundation, and installed poles and piles so that the area of the Second Daigokuden Garden could be known. Second, Donggung Palace and Wolji Pond, Gyeongju where the restoration of individual elements was made, preemptively restored the remains of traditional gardens based on pond garden estuaries and feedbacks that were confirmed through initial excavation. Huanghuazhen Area in Yuanmingyuan Garden was restored based on Western copper plate prints and related records, but further data found after the restoration confirmed that it was restored differently than it is now. East Palace Garden in Heijokyo Palace covered existing features with soil and restored buildings on them. Typical garden elements such as landscape stone and waterways were preserved and exposed. Third, foundation restore is a case in which the base is identified through the current state of the traditional garden site, it is important to restore the foundation first and secure the territoriality when there is no restoration plan for the elevation structure or size of the garden relics. Restoration of individual garden elements requires careful examination of the literature by limiting the restoration of objects that can be restored through the examination of the literature for each element, such as some buildings or facilities in the traditional garden site.