• Korean Journal of Materials Research
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• v.17 no.12
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• pp.654-659
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• 2007

Austenite precipitation behavior was studied with solidification rates and alloying contents, N and Cr, in duplex stainless steels by directional solidification. Directional solidification experiments were carried out with solidification rates, $1{\sim}100mm/s$, and N and Cr contents, $0{\sim}0.27wt.%,\;25{\sim}28wt.%$ respectively, in a duplex stainless steel, CD4MCU. As the solidification rate increases, the dendrite spacing reduced and the austenite phase in the ferrite matrix became finer. The volume fraction of austenite phase increased and its shape went to be round with increasing nitrogen contents in duplex stainless alloys. The Cr alloying element, even though it is a ferrite former, showed to enhance the nitrogen solubility in the alloy and caused the austenite round and finer. Also, Cr was supposed to decrease the austenite volume fraction, but it increased the austenite slightly due to increasing nitrogen solubility during solidification.

• Journal of Pharmaceutical Investigation
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• v.38 no.6
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• pp.381-385
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• 2008

Isosorbide dinitrate is an oral assiatant therapy agent of angina pectoris, myocardial infarction and congestive heart failure. The objective of this study was to formulate sustained release containing isosorbide dinitrate and assess their formulation variables. Pellets were prepared by fluid bed process and consist of drug layer and membrane layer. The pellets were coated with ethylcellulose along with $5{\sim}15%$ of plasticizer such as triacetin and diethyl butylrate. In vitro evaluation study was performed by comparative dissolution test between test and reference isosorbide dinitrate preparation. We could prepare sustained pellets of isosorbide dinitrate by fluid bed process which were reduced process time and had high content. The pellet coated with 1% ethylcellulose and triacetin(l5%) had a similar dissolution behavior compare to reference isosorbide dinitrate preparation controlling initial dissolution and those of dissolution at 30 min were 17.25 and 17.09%, respectively. Difference factor and similarity factor were $0{\sim}15$ and $50{\sim}100$ and there was no significant difference in bioequivalence between formulations. It might be concluded that our sustained release pellet of isosorbide dinitrate could be an alternatively delivery system to reference drug preparation.

• Journal for History of Mathematics
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• v.20 no.1
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• pp.1-16
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• 2007

In the 19th century, Chosun mathematicians studied the most distinguished mathematicians Qin Jiu Shao(泰九韶), Li Ye(李治) Zhu Shi Jie(朱世傑) in Song(宋), Yuan(元) Dynasty and they established a solid theoretical development on the theory of equations. These studies began with their study on Si yuan yu jian xi cao(四元玉鑑細艸) compiled by Luo Shi Lin(羅士琳). Among those Chosun mathematicians, Lee Sang Hyuk(李尙爀, $1810{\sim}?$) and Nam Byung Gil(南秉吉 $1820{\sim}1869$) contributed prominently to the research. Relating to Si yuan yu jian xi cao, Nam Byung Gil and Lee Sang Hyuk compiled OgGamSeChoSangHae(玉監細艸詳解) and SaWonOgGam(四元玉鑑), respectively and then later they wrote SanHakJeongEi(算學正義) and IkSan(翼算), respectively. The latter in particular contains most creative results in Chosun Dynasty mathematics. Using these books, we study the relation between the development of Chosun mathematics and Si yuan yu jian.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.161-165
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• 2008

This study was performed for the purpose of monitoring monthly levels of two pathogenic microorganisms, Cryptosporidium and Giardia, from November 2005 to August 2007 in Sangsa Lake. Water temperatures, pH and DO fluctuated seasonally at the study site. Annual mean values of BOD, COD and SS were $0.8\;mg\;L^{-1}$, $2.3\;mg\;L^{-1}$ and $1.9\;mg\;L^{-1}$ respectively. Although there was distinct seasonal variation in water chemistry and chlorophyll $\underline{a}$ concentration, the lake generally contains low concentrations of nutrients and chlorophyll $\underline{a}$. The relative abundance of coliform bacteria was always greater than that of fecal coliform. The fecal coliform bacteria comprised $8.5{\sim}22.1%$ of total coliform bacteria. Seasonal analysis of Cryptosporidium and Giardia levels in the study site showed that in winter (November through February), Cryptosporidium oocysts and Giardia cysts were most abundant ($1.1{\sim}1.8\;{\times}\;10\;cells\;L^{-1}$ and $3.8{\sim}5.1\;{\times}\;10\;cells\;L^{-1}$, respectively), while in summer (July through September) the abundance was lowest ($0.0{\sim}0.3\;{\times}\;10\;cells\;L^{-1}$ and $0.9{\sim}2.9\;{\times}\;10\;cells\;L^{-1}$, respectively). Molecular identification revealed two subtypes of Cyrptosporidium parvum in Sangsa Lake.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.733-736
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• 2000

Lignin is usable as fuels and heavy oil additives if depolymerized to monomer unit, because the chemical structures are similar to high octane materials found in gasoline. In this study, the solvent-phase thermal cracking(solvolysis) of lignin was performed at the various temperature and time in a laboratory tubular reactor. Conversion yield was measured for the properties of thermal cracking and liquefaction reaction of lignin. Highest conversion yield when acetone was used as thermal cracking solvent was 55.5% at $350^{\circ}C$, 50minutes and highest tar generation were $260{\sim}350mg/g\;{\cdot}\;lignin$ at $250^{\circ}C$, and highest conversion yield after tar removal was 76.88% at $300^{\circ}C$, 30minutes. Conversion yield, product compositions and amounts were determined by tar degradation yield.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.121-130
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• 2007

In this paper, we propose a reversible watermarking scheme in the JPEG compression domain. The reversible watermarking is useful to authenticate the content without the quality loss because it preserves the original content when embed the watermark information. In the internet, for the purpose to save the storage space and improve the efficiency of communication, digital image is usually compressed by JPEG or GIF. Therefore, it is necessary to develop a reversible watermarking in the JPEG compression domain. When the watermark is embedded, the lossless compression was used and the original image is recovered during the watermark extracting process. The test results show that PSNRs are distributed from 38dB to 42dB and the payload is from 2.5Kbits to 3.4Kbits where the QF is 75. Where the QF of the Lena image is varied from 10 to 99, the PSNR is directly proportional to the QF and the payload is around $1.6{\sim}2.8Kbits$.

• (The)Study of the Eastern Classic
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• no.66
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• pp.251-276
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• 2017

This article is an attempt to identify the difference between "Oneness between Heaven and Man(天人合一)" thought proposed by Zhoudunyi(周敦?) in 'Taijirushuo(太極圖說)' and "Cheon-In-Sim-Seong-Haap-Il(A diagram about Unifying Heaven, Human, and Mind-and-Heart)(天人心性合一)" thought presented by Kwonkun(權近) in 'Ip-Hak-Do-Seol(入學圖說)'. Oneness between Heaven and Man thought, which have developed into practical ideas centered on self-cultivation theory, have a philosophical depth and logical system by Zhoudunyi(周敦?) with 'Taijirushuo(太極圖說)' in order to summarize the metaphysical cosmology and the treatise of human nature in Dynasty Song. Zhoudunyi established the concept of Wuji(無極) corresponding to Heaven(天), and suggested unified cosmology of 'Wuji(無極)-Taiji(太極)-Yin and Yang(陰 陽)-Five elements(五行)-Human(人間)-Everything(萬物)'. His cosmology is the perception that heaven, the creator of all things, is the relationship of unity, which is connected by man as the creature and the Order(命)and Nature(性). Thus, when people restores one's nature and realized that it is a mandate from Heaven, he said that heavenly unity can be realized and become a Saint(聖人). The idea of Zhoudunyi(周敦?) comes to Zhu Xi(朱熹) about 120 years later and it is concluded to be converged the Neo-Confucianism with Lichi theory. Accordingly, Zhoudunyi(周敦?) is evaluated as the master of the Neo-Confucianism to posterity. KwonKun suggested the idea of "Cheon-In-Sim-Seong-Haap-Il(A diagram about Unifying Heaven, Human, and Mind-and-Heart)(天人心性合一)" in 'Ip-Hak-Do-Seol(入學圖說)' at the end of Goryeo Dynasty. KwonKun's "Cheon-In-Sim-Seong-Haap-Il" thought is logically coherent by adding an element of the doctrines of Chu-tzu to his teacher Yi Saek's "Chun-In-Mu-Gan" and arranging that the functions of my mind and Li(理) are all together. Whereas Zhuodunyi is concerned with the creation principle of the universe and all things, KwonKun mainly cares about Heaven(天), Human(人), and Heart (心), and Nature(性) in the view of psychology. In addition, he suggested that "Cheon-In-Sim-Seong-Haap-Il" can be achieved by self-cultivation centered of Gyeong-thought(敬思想). The idea of KwonKun has become a stepping stone to the development of the doctrines of Chu-tzu based on psychology. His ideas came to Yi Hwang about 150 year later, and are integrated into four clue-seven emotion (Sadan Chiljung四端七情) thesis and Gyeong-thought(敬思想). However, unlike the Zhoudunyi, KwonKun is not properly evaluated despite his academic accomplishments.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.551-561
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• 1998

Plasma membrane from the fungal cells (Aspergillus phoenicis, Rhizopus acidus, Candida albicans) treated with sodium benzoate (S.B), potassium sorbate (P.S) and calcium propionate (C.P) during the cultivation were separated. The contents and patterns of plasma membrane proteins compared with those of the control. The growth of A. phoenicis was decreased by the average 64.0% in the S.B treatment. That of R. acidus was inhibited by the average 69.0% in the P.S treatment. Also, That of C. albicans was showed the deminution of the average 59.5% in the S.B treatment. The contents of protein involved in the plasma membrane of the each fungal cells were inhibited the average 41.0%, 41.7% and 59.5% in the S.B treatment, respectively. In case of A. phoenicis, the changes in the protein pattern involved in the plasma membraneshowed the aspect similar to the control on the 1st day and 2nd day of cultivation in the treatment group, but $116\;KD{\sim}97\;KD$ band almost disappeared in the 5th day of cultivation, and $45\;KD{\sim}29\;KD$ band was uncleared through the cultivation. In S.B treatment group R. acidus was showed the loss of $116\;KD{\sim}97\;KD$ band from the middle stage of cultivation and P.S, and C.P treatment group were started the loss at the early stage and completely lost at the 36 hours of cultivation. In C. albicans, $116\;KD{\sim}97\;KD$ band were started the loss at the early stage to compare with the control and $66\;KD{\sim}45\;KD$ band were dimmed at the 96 hours of cultivation. Especially, the C.P treatment group were perfectly lost at the 96 hours of cultivation.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.261-265
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• 2008

This study was carried out to investigate the effects of stem cutting ages and harvest time on the growth and yield of potato 'Dejima' in aeroponics. The stem cuttings were produced from in vitro plantlets and transplanted into an aeroponic system with 20, 30, 40 and 50 day-old stem cuttings (DOS). Tubers were harvested 60, 70, 80 and 90 days after transplanting (DAT) and sorted into following categories: $1{\sim}5$, $5{\sim}10$, $10{\sim}20$, $20{\sim}30$, $30{\sim}40$ and over 40 g. Plant height from the 40 DOS was the highest during the growing periods but no significant difference was observed on 75 DAT. The tuber weight increased until 90 DAT with the greatest weight of tubers in the 20 and 40 DOS. However, there was no significant difference among 20, 30 and 40 DOS in the number and weight of tubers. Harvesting at 80 and 90 DAT increased the number of tubers over 5 g, which are usually considered as appropriate for direct field planting.

• The Korean Journal of Quaternary Research
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• v.20 no.2
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• pp.51-57
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• 2006

Terrace stratigraphy of the southeastern coastal areas of Korea is reappraised on the basis of terrace mapping and geochronology. Coastal terraces are divided into uHT ($90{\sim}130\;m$), HT ($63{\sim}86m$), MT ($36{\sim}55\;m$), and LT ($8{\sim}25\;m$) according to altitude. Among these, the Lower Terrace I is interpreted to have formed during MIS 5e based on Tephras Aso-4 (MIS 5c), Ata(MIS 5d or 5e) and OSL data. The age of Lower Terrace II is thought to be MIS 5a based on tephras and OSL data. The uplift rate in the SE part of Korea during the formation of the Lower Terrace (i.e. the MIS 5) ranges from 0.08 to 0.25 mm/yr and averages as 0.15 mm/yr. Such value is quite small in comparison to that of Japan, Taiwan or many other tectonically active areas in the world.