• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1137-1148
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• 2021

The main obstacle for implementing CSIDH-based cryptography is that it requires generating a kernel of a small prime order to compute the group action using Velu's formula. As this is a quite painstaking process for small torsion points, a new approach called radical isogeny is recently proposed to compute chains of isogenies from a coefficient of an elliptic curve. This paper presents an optimized implementation of radical isogenies and analyzes its ideal use in CSIDH-based cryptography. We tailor the formula for transforming Montgomery curves and Tate normal form and further optimized the radical 2- and 3- isogeny formula and a projective version of radical 5- and 7- isogeny. For CSIDH-512, using radical isogeny of degree up to 7 is 15.3% faster than standard constant-time CSIDH. For CSIDH-4096, using only radical 2-isogeny is the optimal choice.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.56-69
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• 2022

Silk is a unique natural biopolymer with outstanding biocompatibility, high mechanical strength, and superior optical transparency. Due to its excellent properties, silk has been widely reported as an ideal biomaterial for several biomedical applications. Recently, fluorescent silk protein, a variant of native silk, has been reported as a biophotonic material with the potential for bioimaging and biosensing. Despite the realization of fluorescent silk, the traditional degumming process of fluorescence silk is crude and often results in fluorescence loss. The loss of fluorescent properties is attributed to the sensitivity of silk fibroin to temperature and solvent concentration during degumming. However, there is no comprehensive information on the influence of these processing parameters on fluorescence evolution and decay during fluorescent silk processing. Therefore, we conducted a spectroscopic study on fluorescence decay as a function of temperature, concentration, and duration for fluorescent silk cocoon degumming. Sodium carbonate solution was tested for degumming the fluorescent silk cocoons with different concentrations and temperatures; also, sodium carbonate solution is combined with Alcalase enzyme and triton x-100 to find optimal degumming conditions. Additionally, we conducted a molecular dynamics study to investigate the fundamental effect of temperature on the stability of the fluorescent protein. We observed degumming temperature as the prime source of fluorescent intensity reduction. From the MD study, fluorescence degradation originated from the thermal agitation of fluorescent protein Cα atoms and fluctuations of amino acid residues located in the chromophore region. Overall, degumming fluorescent silk with sodium carbonate and Alcalase enzyme solution at 25 ℃ preserved fluorescence.

• Journal of Korean Philosophical Society
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• v.123
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• pp.87-110
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• 2012

The kitsch was emerged from the people's cultural desire in the conditions of the various duplicating technology, the capital economy system, and the civil revolution in the western modern mass society. But it is underestimated constantly because of the conspicious consumption and the aesthetic inadequacy. Even though some kitsches are elevated to the 'kitsch arts' in the historical description of the modern arts, still the most of kitsches are remained as 'just kitsches' and excluded from the aesthetic research according to the double standard. In this essay, I research for whether anti-kitsch theory is convincing theoretically and practically. Anti-kitsch theory criticizes the kitsch on the basis of the modernist aesthetics, in which the 'fine art' provokes the aesthetic pleasure in the disinterested contemplation. But kitsch purposes for the sensual gratification and the sentimentality. So the anti-kitish theorists conclude that the kitsch is the bad taste. In critically analyzing the argumentation of Greenberg's. Kaplan's and $C{\tilde{a}}linescu^{\prime}s$, I refute the privileged prejudice of the ideal critic. They don't justify the criteria of the classification of 'art'/ 'kitsch'. They supplement the economical and the political grounds for the evaluative theory of the kitsch. But the argumentation of the kitsch is consumed conspicuously and results in the unlettered masses is not sufficient. People produce and enjoy the kitsches in the various ways. People envelope the genres, styles and media of the kitsches and they try to suggest the new horizon of the popular aesthetics. So anti-kitsch theories cannot be accepted because they adhere to the elitism and formalism. The exclusion of the kitsch is the derogation for people's taste. Also they didn't reflect the contemporary cultural practice and the aesthetic needs in the system of post-art. The alternative aesthetics of the kitsch is the topic of my next essay.

• The Journal of Korean Philosophical History
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• no.32
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• pp.43-78
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• 2011

The two schools which eventually came to form the "Northerners party" in the middle period of the Joseon dynasty, were Nam'myeong school and Hwadam school. Nam'myeong's philosophy, which emphasized the importance and merit of acting upon respect and righteousness(敬義), encouraged many people to organize righteous militias during the war with the Japanese in the 1590s, and when Jeong In-hong established himself as the leader of the Northerners party during the reign of King Gwang'hae-gun, the philosophy of the party and the school continued to thrive. Also, Hwadam's philosophy, which tried to understand Neo-Confucianism from a flexible point of view and demonstrated a level of openness toward it, had a considerable influence upon the Northerners school as well. It seems Nam'myeong Jo Shik and Hwadam Seo Gyeong-deok were the ones who ultimately enabled the Northerners party to be more active in their operations of the government and also to approach more freely toward the ideology of Neo-Confucianism. Prime examples of the party's stance and attitude, and also of the school's philosophy and perception of the world, were figures like Jeong In-hong and Heo Gyun from the 'Majority Northerners(大北) party,' and Kim Shin-guk and Nam I-gong from the 'Minority Northerners(小北) party.'Since the time of King Injo's ascension to the throne in 1623, the philosophical society of Joseon came to be occupied by schools who were deeply committed and dedicated to the teachings of Ju Hi and his Neo-Confucianism, such as the Twe'gye and Yulgok schools, and as a result the Northerners' philosophy was pushed away from its former formidable status. Their political philosophy was also partially responsible for their fall, as they believed only them were the ideal Confucian figures(君子黨), and never appreciated the stances of other political factions. In the middle of the 17th century, passing through a war with the Manchurian Qing dynasty as well, they further became a mere undercurrent. Yet their thinking and philosophy partially survived, as it managed to affect and influence the Southerner school scholars who were living in the vicinity of the capital in the mid and late 17th century, as well as the "Shilhak" scholars such as Yi Ik/李瀷 in the 18th century, on a certain level. The Northerners faction was a party and a school which led the political and philosophical societies of Joseon, alongside the Westerners and Southerners, in the middle period of the Joseon dynasty. Recently, studies of Jo Shik and Seo Gyeong-deok, figures who were the roots of the Northerners faction, and studies of how the Northerners' political philosophy was inherited to the following generations, have been published and announced. All these efforts will enrich future studies dealing with the political history and philosophical history of the middle and latter periods of the Joseon dynasty.