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Yang, Yunfei;Lin, Jiaben;Feng, Song;Deng, Hui;Wang, Feng;Ji, Kaifan
- Journal of The Korean Astronomical Society
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- v.46 no.5
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- pp.191-200
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- 2013
Full-disk solar images are provided by many solar telescopes around the world. However, the observed images show Non-Radial Variation (NRV) over the disk. In this paper, we propose algorithms for detecting distortions and restoring these images. For detecting NRV, the cross-correlation coefficients matrix of radial profiles is calculated and the minimum value in the matrix is defined as the Index of Non-radial Variation (INV). This index has been utilized to evaluate the H images of GONG, and systemic variations of different instruments are obtained. For obtaining the NRV's image, a Multi-level Morphological Filter (MMF) is designed to eliminate structures produced by solar activities over the solar surface. Comparing with the median filter, the proposed filter is a better choice. The experimental results show that the effect of our automatic detection and restoration methods is significant for getting a flat and high contrast full-disk image. For investigating the effect of our method on solar features, structural similarity (SSIM) index is utilized. The high SSIM indices (close to 1) of solar features show that the details of the structures remain after NRV restoring.
https://doi.org/10.5303/JKAS.2013.46.5.191 인용 PDF KSCI

유석종
- Journal of the Korean Society for information Management
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- v.12 no.2
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- pp.85-101
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- 1995
Conventional indexing sytstems support only full-text indexing method for electronic documents and do not use logical structure of documents in retrieval. Most electronic documents are in different formats depending on various systems. Also, they only indicate physical style of the document without considering any logical structure. Thus, in the effort to standardize the exchange of documents. IS0 developed SGML(Stadard Generalized Markup Language) which contains information about logical structure of the documents. In this paper, to resolve the disadvantages of full-text indexing method and to use standard document format. indexing system for SGML document is designed and implemented. In this system, user can assign indexing domain on elements, thus the logical structure of document is reflected in retrieving information. Various retrieval methods can be implemented by using the structural information of the document. In addition, automatic indexing for SGML Hangul document is supported in this system
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Bae, Minyoung;Kang, Ju-Sung;Yeom, Yongjin
- Journal of the Korea Institute of Information Security & Cryptology
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- v.27 no.3
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- pp.449-457
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- 2017
In this paper, we analyze the security and performance of the Quantis Quantum random number generator in terms of cryptography through experiments. The Quantis' post-processing is designed to output full-entropy via bit-matrix-vector multiplication based on mathematical background, and we used the min-entropy estimating test of NIST SP 800-90B so as to verify whether the output is full-entropy. Quantis minimizes the effect on the random bit rate by using an optimization technique for bit-matrix-vector multiplication, and compared the performance to conditioning functions of NIST SP 800-90B by measuring the random bit rate. Also, we have distinguished what is in Quantis' post-processing to the standard model of NIST in USA and BSI in Germany, and in case of applying Quantis to cryptographic systems in accordance with the CMVP standard, it is recommended to use the output of Quantis as the seed of the approved DRBG.
https://doi.org/10.13089/JKIISC.2017.27.3.449 인용 PDF KSCI HTML