• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.253-260
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• 2019

Radiation dose enhancement is a method of increasing the cross section of interaction, thus increasing the deposited dose. This can contribute to linear energy transfer, LET and relative biological effectiveness, RBE. Previous studies on dose enhancement have been mainly focused on X, ${\gamma}-rays$, but in this study, the dose enhancement was analyzed for proton using Monte Carlo simulation using MCNP6. Based on the mathematical modeling method, energy spectrum and relative intensity of spread out Bragg-peak were calculated, and evaluated dose enhancement factor and dose distribution of dose enhancement material, such as aurum and gadolinium. Dose enhancement factor of 1.085-1.120 folds in aurum, 1.047-1.091 folds in gadolinium was shown. In addition, it showed a decrease of 95% modulation range and practical range. This may lead to an uncertain dose in the tumor tissue as well as dose enhancement. Therefore, it is necessary to make appropriate corrections for spread out Bragg-peak and practical range from mass stopping power. It is expected that Monte Carlo simulation for dose enhancement will be used as basic data for in-vivo and in-vitro experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.872-877
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• 2018

STEAM is an acronym for Science, Technology, Engineering, Arts, and Mathematics. It is considered important to equip students with a creative thinking ability and the core competences required in future society, helping them devise new ideas emerging from branches of study. This study is about the convergence of instructional design in private finance for the life sciences, which aims to foster talent through problem-based learning (PBL). Skills like collaboration, creativity, critical thinking, and problem solving are part of any STEAM PBL, and are needed for students to be effective. STEAM projects give students a chance to problem-solve in unique ways, because they are forced to use a variety of methods to solve problems that pop up during these types of activities. The results of this study are as follows. First is the structured process of convergence lessons. Second is the convergence lesson process. Third is the development of problems in the introduction of private finance and the life sciences for a convergence lesson at Dornod University. Learning motivation shows the following results: understanding of learning content (66.6%), effectiveness (63.3%), self-directed learning (59.9%), motivation (63.2%), and confidence (63.3%). To make an effective model, studies applying this instructional design are to be implemented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.160-168
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• 2019

In this study, we propose a verification method for a planar-phased array radar system using a near-field beam focusing(NFBF) test method. We then confirmed the validity of the results. The proposed method can be used to verify a radar system in the near-field range of twice the antenna aperture size, and this is done in the same manner as the field system performance test conducted in a non-outdoor electromagnetic anechoic chamber. The test configuration and procedure for verifying the NFBF using near-field energies were reviewed. In addition, the phase compensation values of additional individual channels were quantified through mathematical verification of the beam-steered NFBF test. Based on a theoretical verification, the actual NFBF test was performed and the validity of the test method was confirmed through comparison with ideal analytical results.

• The Journal of Korean Philosophical History
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• no.37
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• pp.97-134
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• 2013

Kim Ee-man was born and grew up in Jecheon (堤川). As a government officer and a Confucian scholar belonging to Namin School, Kim Ee-man was active in the early and middle of 18th century. Kim Ee-man composed good poems since he was a child. In addition to being a good poet, Kim Ee-man later became a model government officer, who had thorough awareness on serving citizens (爲民). When he was a governor in Yangsan (梁山) county, he built an embankment for farmers by out of his own salary. The academic world of Kim Ee-man faithfully succeeded the basis of Toegyehak (退溪學) and he took Sohak (小學) as important. The reason of Kim Ee-man having established a practical guideline in the form of inscription and proverbs was also directly related to the issue of moral practice. Kim Ee-man also received the influence of ancient classic study from his teacher Lee Seo-woo (李瑞雨) and took Yookgyeong (六經, Six Classics in China) important in practice. Kim Ee-man started the study on Joojahak (朱子學, the doctrines of Chu-tzu) in later years. He became more thorough in being a public figure while reinforcing effort on differentiating the principle of heaven (天理) and human desire (人欲).

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.101-111
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• 2004

Preneel, Govaerts, and Vandewalle considered the 64 basic ways to construct a collision resistant hash function from a block cipher. They regarded 12 of these 64 schemes as secure, though no proofs or formal claims were given. Black, Rogaway, and Shrimpton presented a more proof-centric look at the schemes from PGV. They proved that, in the black box model of block cipher, 12 of 64 compression functions are CRHFs and 20 of 64 extended hash functions are CRHFs. In this paper, we present 64 schemes of block-cipher-based universal one way hash functions using the main idea of PGV and analyze these schemes in the black box model. We will show that 30 of 64 compression function families UOWHF and 42 of 64 extended hash function families are UOWHF. One of the important results is that, in this black box model, we don't need the mask keys for the security of UOWHF in contrast with the results in general security model of UOWHF. Our results also support the assertion that building an efficient and secure UOWHF is easier than building an efficient and secure CRHF.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.97-106
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• 2008

Quality of Protection(QoP) provides a standard that can evaluate networks offering protection. Also, QoP estimates stability of the system by quantifying intensity of the security. Security should be established based on the circumstance which applied to appropriate level, and this should chose a security policy which fit to propose of network because it is not always proportioned that between stability of security mechanism which is used at network and performance which has to be supported by system. With evolving wireless networks, a variety of security services are defined for providing secure wireless network services. In this paper, we propose a new QoP model which makes up for weak points of existing QoP model to choose an appropriate security policy for wireless network. Proposed new QoP model use objectively organized HVM by Flow-based Abnormal Traffic Detection Algorithm for constructing Utility function and relative weight for constructing Total reward function.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.11-21
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• 2009

The NTRU cryptosystem proposed by Hoffstein et al. in 1990s is a public key cryptosystem based on hard lattice problems. NTRU has many advantages compared to other public key cryptosystems such as RSA and elliptic curve cryptosystems. For example, it guarantees high speed encryption and decryption with the same level of security, and there is no known quantum computing algorithm for speeding up attacks against NTRD. In this paper, we analyze the security of NTRU against the simple power analysis (SPA) attack and the statistical power analysis (STPA) attack such as the correlation power analysis (CPA) attack First, we implement NTRU operations using NesC on a Telos mote, and we show how to apply CPA to recover a private key from collected power traces. We also suggest countermeasures against these attacks. In order to prevent SPA, we propose to use a nonzero value to initialize the array which will store the result of a convolution operation. On the other hand, in order to prevent STPA, we propose two techniques to randomize power traces related to the same input. The first one is random ordering of the computation sequences in a convolution operation and the other is data randomization in convolution operation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.33-43
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• 2003

In this paper, we proposed a real-time watermarking algorithm to be combined and to work with a DWT(Discrete Wavelet Transform)-based image compressor. To reduce the amount of computation in selecting the watermarking positions, the proposed algorithm uses a pre-established look-up table for critical values, which was established statistically by computing the correlation according to the energy values of the corresponding wavelet coefficients. That is, watermark is embedded into the coefficients whose values are greater than the critical value in the look-up table which is searched on the basis of the energy values of the corresponding level-1 subband coefficients. Therefore, the proposed algorithm can operate in a real-time because the watermarking process operates in parallel with the compression procession without affecting the operation of the image compression. Also it improved the property of losing the watermark and the efficiency of image compression by watermark inserting, which results from the quantization and Huffman-Coding during the image compression. Visual recognizable patterns such as binary image were used as a watermark The experimental results showed that the proposed algorithm satisfied the properties of robustness and imperceptibility that are the major conditions of watermarking.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.435-444
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• 2021

This paper discusses the geometrical interpretation of the Taegeuk Shapes of Kameun Temple through the geometric analysis of mathematics. Based on the literature, This paper attempted to clarify that the origin of Gameunsa's founding of the spirit of patriotism may coincide with historical records through historical literature and geometric meaning. First, the background of the founding of Kameun temple, geographical location located near the East Sea, especially the history of the ancient Chinese mathematics at the time, And that mathematical knowledge influenced all fields such as agriculture, architecture, and art. Secondly, it is related to the historical record as the space of about 60 centimeters, which is uniquely underground, was identified as the structure of the excavated space. It is thought that there is a strong correlation with the origin that the King Munmu changed into a dragon, and set up the temple to be able to stay. Based on these, the clues of the interpretation of the taegeuk and the triangular pattern were searched in the samcheon yanggi(參天兩地) of the Oriental and circumference of the Western. The taegeuk and triangular patterns represent the symbols of yin-yang harmony, which correspond to the origin of its creation. the Korean people regarded the mysterious dragon as a symbol of yinyang harmony. In conclusion the Shapes of Kameun temple's stone is consistent with the contents mentioned in the historical record.

• Journal of Internet of Things and Convergence
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• v.7 no.2
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• pp.21-29
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• 2021

In this study, it is necessary to supplement the Korean language curriculum in order for international students to adapt and settle in Korea in an era where education is being transformed into future education due to the 4th industry. In the KFL (Korean as a Foreign Language) situation encountered by international students, they suffer from difficulties in university mathematics due to communication problems due to lack of language ability, which is one of the stress factors for cultural adaptation in the Korean language education program. To solve this problem, we analyzed ESL programs in English-speaking countries and KSL programs in Korea to set educational goals, curriculum, and educational methods to achieve goals for international students, and to establish curriculum and learning processes. Therefore, the Korean language education program (KSL program) for foreign students in the Korean language curriculum should also be supplemented by accepting the advantages of setting accurate goals for the ESL program and linking it with university graduation in the curriculum of English-speaking countries. In addition, for international students to learn Korean, an integrated Korean language education course and management system using IT suitable for the 4th industrial age is needed.