• Bulletin of the Korean Mathematical Society
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• v.37 no.1
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• pp.191-207
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• 2000

Let R be a ommutative ring with unity and F a finite free R-module. For a nonnegative integer r, there exists a natural filtration of$S_r(S_2F)$ such that its associated graded module is isomorphic to $\Sigma_{{\lambda}{\epsilon}{\tau}_r}\;L_{\lambda}F$, where ${\Gamma}_{\gamma}$ set of partitions such that $$\mid${\lambda}$\mid$-2r,{{\widetilde}{\lambda}}-{{\widetilde}{\lambda}}_1},...,{{\widetilde}{\lambda}}_k},\;each\;{{\widetilde}{\lambda}}_t}$,is even. We call such filtrations plethysm formulas. We extend the above plethysm formula to the version of chain complexes. By plethysm formula we mean the composition of universally free functors. $Let{\emptyset}:G->F$ be a morphism of finite free R-modules. We construct the natural decomposition of $S_{r}(S_2{\emptyset})$,up to filtrations, whose associated graded complex is isomorphic to ${\Sigma}_{{\lambda}{\varepsilon}{\tau}}_r}\;L_{\lambda}{\emptyset}$.

• Journal of Internet of Things and Convergence
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• v.6 no.2
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• pp.25-29
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• 2020

The elliptic curve crypto-algorithm is widely used in authentication for IoT environment, since it has small key size and low communication overhead compare to the RSA public key algorithm. If the scalar multiplication, a core operation of the elliptic curve crypto-algorithm, is not implemented securely, attackers can find the secret key to use simple power analysis or differential power analysis. In this paper, an elliptic curve scalar multiplication algorithm using a randomized scalar and an elliptic curve point blinding is suggested. It is resistant to power analysis but does not significantly reduce efficiency. Given a random r and an elliptic curve random point R, the elliptic scalar multiplication kP = u(P+R)-vR is calculated by using the regular variant Shamir's double ladder algorithm, where l+20-bit u≡rn+k(modn) and v≡rn-k(modn) using 2^lP=∓cP for the case of the order n=2^l±c.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.311-314
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• 1992

A new monocyclic ${\beta}-lactam$ analogue, sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3) was synthesized from L-aspartic acid. Starting from L-aspartic acid, (S)-1-benzyl-4-benzyloxycarbonyl-2-azetidinone (7) was synthesized in four steps by following the established procedures and converted into (3R,4S)-3-amino-1-t-butyldimethylsilyl-4-methoxym ethyl-2-azetidinone (13) in six steps. Acylation of the amino group of 13 with $2-amino-{\alpha}$ -(methoxyimino)-4-thiazoleacetic acid, desilylation, and sulfonation with sulfur trioxide-pyridine complex followed by ion exchange afforded sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3). Antibacterial activities of this ${\beta}$ -lactam compound 3 were, however, found to be quite low compared to cefotaxime.

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.7-12
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• 2001

The age and growth of the short-necked clam, Paphia undalata, was investigated from 546 samples randomly collected in December 2000 in Kwangyang Bay, Korea. Ages were determined from ring radius of shell and the maximum age was observed to be 2 years. The relationship between shell length (SL) and shell height (SH) of Paphia undalata was SL = 0.2105 ＋ 1.7569 $\times$ SH ($R^2$= 0.98), and the shell length (SL)-total weight (TW) relationship was TW = 2.5824 $\times$ 10$^{-4}$ $\times$ S $L^{2.6769}$ ($R^2$= 0.92). The von Bertalanffy growth parameters were estimated by the non-linear method, with values as follows: $L_{\infty}$ = 81.46 mm, K : 0.20/year, $t_{0}$ = -1.19 year. The von Bertalnanffy growth equation was $L_{t}$ = 81.46(1- $e^{-0}$.20(t+1.19)/), $W_{t}$ = 33.68(1- $e^{-0}$.20(t+1.19)/)$^{2.6769}$.

• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.81-87
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• 2005

The objective of this study was to determine the radical scavenging activity, total phenolic content, antimicrobial activity, minimum inhibitory concentration (MIC) of ethanol extracts of 32 medical plant species that have been commonly used in medicinal plants. Total phenolic index of T. chebula exhibited the highest value (498.01㎎/g), followed by R. coreanus miquel (400.33㎎/g), Sanguisorba officinalis (368.25㎎/g), P. thumbergiana (259.74㎎/g) and Eugenia aromaticum (229.38㎎/g). Radical scavenging activity for the DPPH radical was highest in T. chebula (40.91%, p<0.01), followed by C. sappan (36.50%), S. officinalis (32.92%), R. coreanus miquel (26.54%) and P. thumbergiana (24.50%). The extracts from T. chebula, R. coreanus muquel, C. sappan, E. aromaticum, S. officinalis and C. japonica possessed outstanding antimicrobial activity against Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Lactobacillus plantarum. MIC was determined on those extracts that showed high efficacy against the test organisms. The most potent MIC values were seen for T. chebula extract against P. aeruginosa, S. aurusa, E. coli, B. subtilis, L. plantarum and S. Typhimurium at 7.8, 7.8, 15.6, 7.8, 125 and 31.2㎍/mL, respectivley. Furthermore, the total phenolic content and radical scavenging activity were very closely correlated for all samples (r=0.78). The coefficient correlations between total phenolic index and antimicrobial activity were 0.91 (E. coli), 0.91 (B. subtillis), 0.79 (P. aeruginosa), 0.79 (S. Typhimurium) and 0.70 (L. plantarum).

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.150-156
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• 2010

The separation performance of a low-pressure hydrocyclone (LPH) was evaluated for suspended-solids removal in a recirculating aquaculture system (RAS). The dimensions of the LPH were 335 mm cylinder diameter, 575 mm cylinder height, 60 mm overflow diameter, 50 mm underflow diameter, and $68^{\circ}$ cone angle. The inflow rate varied (400, 600, 800, and 1,000 mL $s^{-1}$) with 25%, 25%, 20%, and 10% of bypass ($R_f$), respectively. The maximum total separation efficiency (Et) and reduced separation efficiency (E't) for suspended solids from the effluent of the second settlement tank (before biofiltration) were 58.9% and 45.2%, respectively, at an inflow rate of 600 mL $s^{-1}$ and 25% of $R_f$. The maximum Et and E't for suspended solids from the water supply channel (after biofiltration) were 24.4% and 16%, respectively, at an inflow rate of 1,000 mL $s^{-1}$ and 10% of $R_f$. The maximum grade efficiency (Ei) was 51.6% for a 300 ${\mu}m$ particle size at an inflow rate of 600 mL $s^{-1}$ with 23% of $R_f$. The maximum reduced grade efficiency (E'i) was 37.6% for a 300 ${\mu}m$ particle size at an inflow rate of 1,000 mL $s^{-1}$ with 11% of $R_f$. The results indicate that the separation performance of the LPH for suspended solids removal was size selective and that maximum removal occurred at particle sizes ranging from 300 to 500 ${\mu}m$.

• Korean Journal of Materials Research
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• v.7 no.2
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• pp.152-156
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• 1997

In this paper, I meritioned ,I study on thc rnechanochernic;~l effec ts of grountl iljckite To investigate the mechanochemical effects of ground tlickite 1,y planet,~r\- mill. a structul-ill i~nalvsis of dickite prepared with different grinding time has been made 11y X-ray diffraction and ilifierenti,~l tl~i.~-ni;~i analysis. 'l'he $SiO_{4}$ hecira was unchanged bl- milling and remained ;is the local ordering unit s t t - ~ c ~ u ~ - c ~ s in the ground dickitc samples I ) v analyzing the radial distribution function. On the other hand, with an increi~se of the grinding time a decrease of coordination number and atomic distance bet\vccn aluminum and oxygen hi1c.r l~een octurreil, and Li~~antitativcl\. coniirrned them This result corresponded to the local c,hange around aliimi~iuni I>V tliftercntii~l t1ii:rm;il ani~lysis. Therefore, the mechanochemical phenomina of ground tiickite werc3 h e to the local c~l~mge around aluminum \IT. the prolonged grinding.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.34-34
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• 1978

To find out the power tiller's travel and tractive characteristics on the general slope land, the tractive p:nver transmitting system was divided into the internal an,~ external power transmission systems. The performance of power tiller's engine which is the initial unit of internal transmission system was tested. In addition, the mathematical model for the tractive force of driving wheel which is the initial unit of external transmission system, was derived by energy and force balance. An analytical solution of performed for tractive forces was determined by use of the model through the digital computer programme. To justify the reliability of the theoretical value, the draft force was measured by the strain gauge system on the general slope land and compared with theoretical values. The results of the analytical and experimental performance of power tiller on the field may be summarized as follows; (1) The mathematical equation of rolIing resistance was derived as $$Rh=\frac {W_z-AC \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\] sin\theta_1}} {tan\phi \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]+\frac{tan\theta_1}{1}$$ and angle of rolling resistance as $$\theta _1 - tan^1\[ \frac {2T(AcrS_0 - T)+\sqrt (T-AcrS_0)^2(2T)^2-4(T^2-W_2^2r^2)\times (T-AcrS_0)^2 W_z^2r^2S_0^2tan^2\phi} {2(T^2-W_z^2r^2)S_0tan\phi}\] $$and the equation of frft force was derived as$$P=(AC+Rtan\phi)\[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]cos\phi_1 ? \frac {W_z ?{AC\[ [1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]sin\phi_1 {tan\phi[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\]+ \frac {tan\phi_1} { 1} ? W_1sin\alpha $$The slip coefficient K in these equations was fitted to approximately 1. 5 on the level lands and 2 on the slope land. (2) The coefficient of rolling resistance Rn was increased with increasing slip percent 5 and did not influenced by the angle of slope land. The angle of rolling resistance Ol was increasing sinkage Z of driving wheel. The value of Ol was found to be within the limits of Ol =2? "'16?. (3) The vertical weight transfered to power tiller on general slope land can be estim ated by use of th~ derived equation: $$R_pz= \frac {\sum_{i=1}^{4}{W_i}} {l_T} { (l_T-l) cos\alpha cos\beta ? \bar(h) sin \alpha - W_1 cos\alpha cos\beta$$The vertical transfer weight $R_pz$ was decreased with increasing the angle of slope land. The ratio of weight difference of right and left driving wheel on slop eland,$\lambda= \frac { {W_L_Z} - {W_R_Z}} {W_Z} $, was increased from ,$\lambda$=0 to$\lambda$=0.4 with increasing the angle of side slope land ($\beta = 0^\circ~20^\circ) (4) In case of no draft resistance, the difference between the travelling velocities on the level and the slope land was very small to give 0.5m/sec, in which the travelling velocity on the general slope land was decreased in curvilinear trend as the draft load increased. The decreasing rate of travelling velocity by the increase of side slope angle was less than that by the increase of hill slope angle a, (5) Rate of side slip by the side slope angle was defined as $ S_r=\frac {S_s}{l_s} \times$ 100( %), and the rate of side slip of the low travelling velocity was larger than that of the high travelling velocity. (6) Draft forces of power tiller did not affect by the angular velocity of driving wheel, and maximum draft coefficient occurred at slip percent of S=60% and the maximum draft power efficiency occurred at slip percent of S=30%. The maximum draft coefficient occurred at slip percent of S=60% on the side slope land, and the draft coefficent was nearly constant regardless of the side slope angle on the hill slope land. The maximum draft coefficient occurred at slip perecent of S=65% and it was decreased with increasing hill slope angle $\alpha$. The maximum draft power efficiency occurred at S=30 % on the general slope land. Therefore, it would be reasonable to have the draft operation at slip percent of S=30% on the general slope land. (7) The portions of the power supplied by the engine of the power tiller which were used as the source of draft power were 46.7% on the concrete road, 26.7% on the level land, and 13~20%; on the general slope land ($\alpha = O~ 15^\circ ,\beta = 0 ~ 10^\circ$) , respectively. Therefore, it may be desirable to develope the new mechanism of the external pO'wer transmitting system for the general slope land to improved its performance.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.84-88
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• 2009

Cathepsin S is a cysteine protease that affects extracellular matrix remodeling. Recently, several studies have reported that cathepsin S is involved in obesity. Both mouse and human adipose cells produce this enzyme in the early phase of adipocyte differentiation, where it degrades fibronectin. Cathepsin S gene expression is elevated in the adipose tissue of obese mice as compared to that of lean mice. Paecilomyces tenuipes water extracts (PTW) are shown to have an inhibitory effect on cathepsin S activity. In this study, Z-Val-Val-Arg-MCA was used as a cathepsin S-specific substrate in order to examine inhibitory effect of PTW. Supplementing 3T3-L1 cell media with PTW clearly reduced lipid droplet accumulation and cathepsin S-induced adipogenesis. Furthermore, PTW decreased weight gain, subcutaneous adipose tissue growth, the level of serum triglyceride, and total cholesterol in mice fed a high-fat diet. These data suggest that PTW work against adipose cathepsin S and presumably contribute to anti-obese activities.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.77-83
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• 1981

Four-day bioassay method was used in this study to find out toxicity levels of DDT and PCP. From this study it was found that M. chrysophekadion was the most sensitive to DDT with a 96 h-TL sub(m) value of 0.0044 mg/l followed by P. Sutchi with a 96 h-TL sub(m) value of 0.0056 mg/l, and the most resistant was C. Siamensis with a 96 h-TL sub(m) value of 0.0133 mg/l. In the case of PCP, it was also found that M. Chrysophekadion and P. Sutchi were the first and second most sensitive to PCP with a 96 h-TL sub(m) value of 0.065mg/l PCP and 0.125mg/l PCP respectively, as in the case of DDT study. T. Nilotica was found to be the most resistant to PCP with a 96 h-TL sub(m) value of 0.264mg/l PCP. The resistant power of fish to pollution varies with the species of fish and the types of pollutants. In order of decreasing sensitivity of fish to DDT based on TL sub(m), the following sequence is obtained M. Chrysophekadion, P. Sutchi, T Nilotica, P. Gonionotus, K. Bicirrhis, L. Bicolor, C. Carpio, R. Heteromorpha, C. Siamensis while in the case of PCP, M. Chrysophekadion, P. sutchi, L. Bicolor, K. Bicirrhis, P. Gonionotus (R. Heteromorpha, R. Trilineata), C. Siamensis, C. Carpio, T. Nilotica.