• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.38 no.1
• /
• pp.27-34
• /
• 2001

The multiplication algorithm using the primitive irreducible trinomial $x^m+x+1$ over $GF(2^m)$ was proposed by Mastrovito. The multiplier proposed in this paper consisted of the multiplicative operation unit, the primitive irreducible operation unit and mod operation unit. Among three units mentioned above, the Primitive irreducible operation was modified to primitive irreducible trinomial $x^m+x+1$ that satisfies the range of 1$x^m,{\cdots},x^{2m-2}\;to\;x^{m-1},{\cdots},x^0$ is reduced. In this paper, the primitive irreducible polynomial was reduced to the primitive irreducible trinomial proposed. As a result of this reduction, the primitive irreducible trinomial reduced the size of circuit. In addition, the proposed design of multiplier was suitable for VLSI implementation because the circuit became regular and modular in structure, and required simple control signal.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.7
• /
• pp.53-59
• /
• 2018

Purpose - This study examines the effect of control-ownership wedge on stock crash risk. In Korea, controlling shareholders have exclusive control rights compared to their cash flow rights. With increasing disparity, controlling shareholders abuse their power and extract private benefits at the expense of the minority shareholders. Managers who are controlling shareholders of the companies tend not to disclose critical information that would prevent them from pursuing private interests. They accumulate negative information in the firm. When the accumulated bad news crosses a tipping point, it will be suddenly released to the market at once, resulting in an abrupt decline in stock prices. We predict that stock price crash likelihood due to information opaqueness increases as the wedge increases. Research design, data, and methodology - 831 KOSPI-listed firm-year observations are from KisValue database from 2005 to 2011. Control-ownership wedge is measured as the ratio (UCO -UCF)/UCO where UCF(UCO) is the ultimate cash-flow(control) rights of the largest controlling shareholder. Dependent variable CRASH is a dummy variable that equals one if the firm has at least 1 crash week during a year, and zero otherwise. Logistic regression is used to examine the relationship between control-ownership wedge and stock price crash risk. Results - Using a sample of KOSPI-listed firms in KisValue database for the period 2005-2011, we find that stock price crash risk increases as the disparity increases. Specifically, we find that the coefficient of WEDGE is significantly positive, supporting our prediction. The result implies that as controlling shareholders' ownership increases, controlling shareholders tend to withhold bad news. Conclusions - Our results show that agency problems arising from the divergence between control rights and cash flow rights increase the opaqueness of accounting information. Eventually, the accumulated bad news is released all at once, leading to stock price crashes. It could be seen that companies with high control-ownership wedge are likely to experience future stock price crashes. Our study is related to a broader literature that examined the effect of the control-ownership wedge on stock markets. Our findings suggest that the disparity is a meaningful predictor for future stock price crash risk. The results are expected to provide useful implications for firms, regulators, and investors.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.67-71
• /
• 1986

Concentration of dissolved $vitamin\;B_{12}$ in the water of Okjeong lake have been determined by microbiological assay methods on the 20th of August, 1983. Also the relations between the $vitamin\;B_{12}$ and other physical, chemical and biological environmental factors were investigated. $Vitamin\;B_{12}$ was assayed with Euglena gracilis Z strain. The results obtained in this investigation were as follows : 1. Generally, the values of COD and $Cl^-$ were higher than values reported in 1981. 2. The concentration of nutrient salts in the lake water was found to be at a higher level: above the general criterion in a eutrophic lake viz., phosphorous 0.175-0.225 mg/l. 3. Chlorophyll a contents in this lake were $1.1-8.7{\mu}g/l$, 4. The concentration of $vitamin\;B_{12}$ in the water fairly high: 1.25-6.0 ng. It is apparent that concentrations of the $vitamin\;B_{12}$ as well as nutrient salts were high in the water of Okjeong lake. It was found that Okjeong lake was in eutrophic.

• Economic and Environmental Geology
• /
• v.41 no.6
• /
• pp.747-761
• /
• 2008

In order to experiment the acoustic remote classification of seabed sediment, we achieved ground-truth data(i.e. video and grab samples, etc.) and developed post-processing for automatic classification procedure on the basis of 300 kHz MultiBeam Echo Sounder(MBES) backscattering data, which was acquired using KONGBERG Simrad EM3000 at Sock-Cho Port, East Sea of South Korea. Sonar signal and its classification performance were identified with geo-referenced video imagery with the aid of GIS (Geographic Information System). The depth range of research site was from 5 m to 22.7 m, and the backscattering amplitude showed from -36dB to -15dB. The mean grain sizes of sediment from equi-distanced sampling site(50 m interval) varied from 2.86$(\phi)$ to 0.88(\phi). To acquire the main feature for the seabed classification from backscattering amplitude of MBES, we evaluated the correlation factors between the backscattering amplitude and properties of sediment samples. The performance of seabed remote classification proposed was evaluated with comparing the correlation of human expert segmentation to automatic algorithm results. The cross-model perception error ratio on automatic classification algorithm shows 8.95% at rocky bottoms, and 2.06% at the area representing low mean grain size.

• Analytical Science and Technology
• /
• v.15 no.4
• /
• pp.373-380
• /
• 2002

Humic and fulvic acids present in soil of different depth were extracted and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of radioactive elements deposited on soil. Molecular size distribution of the humic and fulvic acids was measured by stirred cell ultrafiltration technique and the structural informations were obtained from their UV-Vis., IR and synchronous fluorescence (SyF) spectral analysis. Main molecular size ranges of the soil 1) humic and fulvic acids were 30~100 kDa (46~56%) and 10~30 kDa (33~43%) respectively, and their overall molecular sizes were found to became smaller with increasing the soil depth. Absorptivities measured at 280 nm in the UV-Visible spectra of humic acids were 1.4~1.5 times higher than those of fulvic acids, and increased with increasing the soil depth. SyF spectral data showed two distinct peak components having maximum peak positions of 428 nm (type I) and 498 nm (type II) for the soil humic and fulvic acids. From the analysis of the peak components, it was found that humic molecules are mainly made up of aromatic compounds corresponding to longer wavelength (type II), and the molecular components increased with increasing the soil depth. Analysis of IR spectral data indicated that the humic molecules contain a higher relative concentration of carboxylic groups than those of fulvic molecules, and the carboxylic group contents are seen to increase as the soil depth increase.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.6
• /
• pp.1098-1106
• /
• 2015

This study aimed to investigate antioxidant activities from 11 forest plants, and determine their total phenolics, flavonoids and proantocyanidins contents. In addition, the antioxidant activities were correlated with antioxidant compounds. Among the samples, Cornus officinalis, Castanea crenata, Lindera erythrocarpa, Carpinus laxiflora and Pourthiaea villosa showed significantly higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) ($IC_{50}=21.12{\sim}28.93{\mu}g/mL$) and 2,2'-azino-bis(3-ethylbenzothia zoline-6-sulfonic acid) (ABTS) ($IC_{50}=28.18{\sim}52.55{\mu}g/mL$) radical scavenging ability with reducing power ($IC_{50}=59.91{\sim}93.64{\mu}g/mL$) than other plants; and C. crenata, L. erythrocarpa and Rubus coreanus showed strong nitric oxide (NO) inhibition activity (${\geq}60%$). In addition, L. erythrocarpa, C. laxiflora and P. villosa showed higher oxygen radical absorbance capacity (ORAC) values (${\geq}1,100{\mu}M$ TE/g sample) than other samples. High total phenolic contents were observed in C. crenata (429.11 mg GAE/g), L. erythrocarpa (437.11 mg GAE/g), C. laxiflora (408.67 mg GAE/g) and P. villosa (404.11 mg GAE/g). The DPPH and ABTS radical scavenging activity with reducing power were significantly correlated with total phenolic contents ($R^2=0.71{\sim}0.79$), but total phenolic contents were not correlated with NO inhibition and ORAC ($R^2=0.35{\sim}0.43$). Therefore, these results suggested that C. officinalis, C. crenata, L. erythrocarpa, C. laxiflora and P. villosa are potential natural antioxidative candidate ingredients.

• Korean Journal of Food Science and Technology
• /
• v.21 no.1
• /
• pp.37-44
• /
• 1989

This study aims at producing red pigment effectively by using protoplast fusion. Auxotrophic mutants of M. anka, $4478-27-37(Thi^-,\;Met^-),\;4478-27-62(Thi^-,\;Arg^-)$ were derived from M. anka, 4478-27. M. anka, $6540-185-24\;(Pan^-,\;Leu^-)$ and M. anka, $6540-185-72\;(Arg^-)$ were derived from M. anka, 6540-185. The optimal conditions of protoplast fromation were at time by using mixtures of chitinase (100mg/ml), cellulase (5mg/ml) and ${\beta}-glucuronidase\;(5mg/ml)$. The protoplast of those auxotrophic mutants were fused effectively, in the solution of 30% PEG $6,000,001M-CaCl_2$, 0.05M-glycine, pH 6.0. Fusion frequencies were 0.70%-0.85%. Fusants, No. 14 and 42 produced highest red pigment among them.

• Journal of the Korean Chemical Society
• /
• v.30 no.4
• /
• pp.394-402
• /
• 1986

Detonation reaction in L.P.G./$O_2$ mixture gas has been investigated over the L.P.G. concentration range of 3∼45 volume%. The variation of detonation velocity with mixture ratio is very interesting as it shows and inflection point near at the stoichiometric ratio. This might be ascribed to the fact that the detonation reactions at fuel-rich condition and fuel-lean condition proceed via different mechanisms. The maximum detonation velocity of 2.65km/sec occurs not at stoichiometric ratio(${\phi}$=1) but at fuel-rich condition (${\phi}$=1.57). Assuming that a stable detonation wave must propagates with the constant velocity, The upper and lower limit of detonation were determined and found to be 40.0 and 3.40 L.P.G. volume% respectively. The shock-heating technique was also utilized for the measurement of self-ignition temperature onsetting a stable detonation wave at varous mixture ratios. The self-ignition temperature at stoichiometric ratio is $742{\pm}3{\circ}K$ and the self-ignition temperature increases as the mixture ratio deviates from the stoichiometric condition.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.20 no.1 s.32
• /
• pp.66-79
• /
• 2007

Objectives : This study was carried out to evaluate anti-tummor effect about apoptosis of Cheongyulsodok-Eum (CSE) Results : 1. Anti-tumor(HL-60 cells) effects of CSE water extracts(Exts) were more effective in high density.($IC_{50:}:572$ ${\mu}g/ml$) 2. The generation of $O_2\;^-$ in HL-60 cells were according to the concentration of CSE water Exts, specially more effective on 100 ${\mu}g/ml$ and 1000 ${\mu}g/ml$ concentration. 3. The SOD activities in HL-60 cells were in proportion as cytotoxicity against HL-60 cells of CSE water Exts. 4. The GPx activities in HL-60 cells were in proportion as cytotoxicity against HL-60 cells of CSE water Exts(more effective on 100 ${\mu}g/ml$ and 1000 ${\mu}g/ml$ concentration), but the catalase activities in HL-60 cells were not effective. 5. DPPH radical scavenging activity of CSE water Exts was effective.(3 ${\mu}g/ml:31.2{\pm}5.2$ %, 10 ${\mu}g/ml:49.6{\pm}7.3$ %, 30 ${\mu}g/ml:35.8{\pm}5.7$ % 100 ${\mu}g/ml:42.3{\pm}6.4$ %) 6. The results of cytotoxicity against HL-60 cells of CSE were as follows. 1) In hexane fraction, the cytotoxicity against HL-60 cells($IC_{50:}:592$ ${\mu}g/ml$) was more effective than against NIH3T3 cells. 2) In ethyl acetate fraction, the cytotoxicity against HL-60 cells was not effective. 3) In butanol fraction, the cytotoxicity against HL-60 cell($IC_{50:}:306$ ${\mu}g/ml$) was more effective than against NIH3T3 cells. 4) In $H_2O$ fraction, the cytotoxicity against HL-60 cells was not effective. Conclusion : These result suggest that CSE has antioxidative effects and anti-tumor effects by apoptosis of free radical($O_2\;^-$) activity, especially butanol and hexane fraction from water extract has more effective in anti-twnor effects.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.6 no.1
• /
• pp.47-80
• /
• 1984

The aim of this paper is to study the classification and arrangement system, the original texts, and the bibliographic deseription of Dae-Jang-Mock-Lock. The results of this study can be summarized as followings; 1. The first carving of Dae-Jang-Mock-Lock was assumed to be completed at latest by 1087 (King Sun-Jong 4, Koryo) when the first carving of Dae-Jang-Kyong, the complete collection of Buddhist Sutra, mas finished. Henee, Dae-Jang-Mock-Lack is safely said to be the oldest catalog in Korea. 2. The major function of Dae-Jang-Mock-Lock mas to facilitate the job of printing, managing, or arranging the Sutra tablets, rather than to serve as its references. 3. Dae-Jang-Mock-Lock mas classified in accordance with the classification sys tern of Gae-Woon-Suck-Kyo-Lock, a chinese Buddhist catalog. This system classified the complete collection of Buddhist Sutra into the three categories of "Mah$\={a}$y$\={a}$na Tripitaka", "Hinayan$\={a}$ Tripitaha", and "collected Biographies of Samgha", at the first gradation. And then the Mah$\={a}$yan$\={a}$ Tripitaka mas divided into the three categories of "Mah$\={a}$y$\={a}$na Sutra", "Mah$\={a}$y$\={a}$na Uparaksa", and "Mah$\={a}$y$\={a}$na Upadesa", at the second gradation. In the same manner the "Hinayan$\={a}$ Tripitaka was divided into "Hinayan$\={a}$ Sutra", "Hinayan$\={a}$ Uparaksa", and "Hinayan$\={a}$ Upadesa". The "Collected Biographies of Samgha" was divided into Brahman Samgha and Chinese Samgha. For this reason we Can name this main classification system as a Tripitaka Classification. 4. The first carving tablets of the Buddhist Sutra from Choen Shelf (天函) to Young Shelf (英函) were the same Sutra that were included in Gae-Woen-Suck-Kyo-Lock (開元釋敎錄), except those 4 omitted sutras of 22 volumes. But the other 7 sutras of 24 volumes were included as an extra addition in "Dae-Jang-Mock-Lock." 5. The 40 shelves and 376 volumes of Buddhist Sutra from the Doo Shelf (杜函) to the Kyong Shelf (輕函) in Dae-Jang-Mock-Lock were copied from the texts of Guran Edition (契丹本) 6. The 36 shelves of Buddhist Sutras from the Bun shelf (磻函) to the Mil shelf (密函) in Dae-Jang-Mock-Lock were the same as those included in Sock-Jung-Woen-Suck-Kyo-Lock (續貞元釋敎錄), except the 3 omitted sutras.