• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.234-237
• /
• 2000

In this paper, the structural, dielectric and piezoelectric properties of the Pb[(S $b_{1}$2/N $b_{1}$2/)$_{0.035}$- $_Mn_{1}$3/N $b_{2}$3/)$_{0.065}$-(Z $r_{0.49}$, $Ti_{0.51}$)$_{0.90}$] $O_3$ ceramics were investigated with respect to the variation of the milling time. Grain size was decreased as the increase of milling time. As the milling time is increased, the particle size of the powder was decreased. Dielectric constant and electromechanical coupling factor (Qm)were slowly increased with the increase of milling time. The highest value of Qm was 1,497 at milling time 8 hour. Temperature coefficient of resonant frequency(TC $F_{r}$) was moved to positive side with the increase of milling time.e.e.e.e.e.e.

• Journal of the Korean Mathematical Society
• /
• v.45 no.1
• /
• pp.177-196
• /
• 2008

Using the results on the coefficients of Hermite-Fej$\acute{e}$r interpolations in [5], we investigate convergence of Hermite and Hermite-$Fej{\acute{e}}r$ interpolation of order m, m=1,2,... in $L_p(0<p<{\infty})$ and associated product quadrature rules for a class of fast decaying even $Erd{\H{o}}s$ weights on the real line.

• Communications of the Korean Mathematical Society
• /
• v.10 no.2
• /
• pp.409-417
• /
• 1995

We consider the $R^k$-valued $(k \geq 1)$ process ${X_n}$ generated by $X_n + 1 = f(X_n)+e_{n+1}$, where $f(x) = (h(x),x^{(1)},x^{(1)},\cdots,x{(k-1)})'$. We assume that h is a real-valued measuable function on $R^k$ and that $e_n = (e'_n,0,\cdot,0)'$ where ${e'_n}$ are independent and identically distributed random variables. We obtained a practical criteria guaranteeing a given process to be geometrically ergodic. Sufficient condition for transience is also given.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.11 no.2
• /
• pp.9-14
• /
• 2007

A signed 3-partite graph is a 3-partite graph in which each edge is assigned a positive or a negative sign. Let G(U, V, W) be a signed 3-partite graph with $U\;=\;\{u_1,\;u_2,\;{\cdots},\;u_p\},\;V\;=\;\{v_1,\;v_2,\;{\cdots},\;v_q\}\;and\;W\;=\;\{w_1,\;w_2,\;{\cdots},\;w_r\}$. Then, signed degree of $u_i(v_j\;and\;w_k)$ is $sdeg(u_i)\;=\;d_i\;=\;d^+_i\;-\;d^-_i,\;1\;{\leq}\;i\;{\leq}\;p\;(sdeg(v_j)\;=\;e_j\;=\;e^+_j\;-\;e^-_j,\;1\;{\leq}\;j\;{\leq}q$ and $sdeg(w_k)\;=\;f_k\;=\;f^+_k\;-\;f^-_k,\;1\;{\leq}\;k\;{\leq}\;r)$ where $d^+_i(e^+_j\;and\;f^+_k)$ is the number of positive edges incident with $u_i(v_j\;and\;w_k)$ and $d^-_i(e^-_j\;and\;f^-_k)$ is the number of negative edges incident with $u_i(v_j\;and\;w_k)$. The sequences ${\alpha}\;=\;[d_1,\;d_2,\;{\cdots},\;d_p],\;{\beta}\;=\;[e_1,\;e_2,\;{\cdots},\;e_q]$ and ${\gamma}\;=\;[f_1,\;f_2,\;{\cdots},\;f_r]$ are called the signed degree sequences of G(U, V, W). In this paper, we characterize the signed degree sequences of signed 3-partite graphs.

• Journal of the Korean Mathematical Society
• /
• v.45 no.2
• /
• pp.425-433
• /
• 2008

Let R be a ring with identity $1_R$ and let U(R) denote the group of all units of R. A ring R is called locally finite if every finite subset in it generates a finite semi group multiplicatively. In this paper, some results are obtained as follows: (1) for any semilocal (hence semiperfect) ring R, U(R) is a finite (resp. locally finite) group if and only if R is a finite (resp. locally finite) ring; U(R) is a locally finite group if and only if U$(M_n(R))$ is a locally finite group where $M_n(R)$ is the full matrix ring of $n{\times}n$ matrices over R for any positive integer n; in addition, if $2=1_R+1_R$ is a unit in R, then U(R) is an abelian group if and only if R is a commutative ring; (2) for any semiperfect ring R, if E(R), the set of all idempotents in R, is commuting, then $R/J\cong\oplus_{i=1}^mD_i$ where each $D_i$ is a division ring for some positive integer m and |E(R)|=$2^m$; in addition, if 2=$1_R+1_R$ is a unit in R, then every idempotent is central.

• Korean Journal of Agricultural Science
• /
• v.38 no.3
• /
• pp.453-458
• /
• 2011

The MC1R (Melanocortin 1 receptor) gene has been known as a causative gene of the coat colors in mammals and responsible for the E (Extension) locus which has three alleles ($E^D$, $E^+$, e) that determines coat colors. The dominant allele $E^D$ produces black or brown colors due to the missense mutation and the recessive e allele has frameshift mutation which shows red or yellow coat colors. Whereas the wild type $E^+$ produces variety of colors due to the interaction with A (Agouti) locus. In this study, PCR-RFLP was performed using two restriction enzymes (BsrF I and MspA1 I) in order to obtain MC1R genotypes in Korean brindle cattle and black cattle. The results showed that all of the animals have the $E^+$ alleles, indicating the $E^+$ allele might related with black coat colors. Later on, the experiments expanded to the 260 Korean candidate bulls whether these animals have the same $E^+$ allele. Among 260 samples investigated, 5% (13/260) of the animals had $E^+$e genotypes, indicating the $E^+$ allele is also present in the candidate bulls in a low frequency. Even though we expected that A locus also affect the black coat color in cattle, all the black coat color animals (brindle and black) have $E^+$ alleles in this study. Therefore, the genotyping of the MC1R gene in candidate bulls will recommended be applied for eliminating of black coat colors in Hanwoo population, if the farmers need to have the brown coat colors only.

• Food Science and Preservation
• /
• v.6 no.2
• /
• pp.206-215
• /
• 1999

Volatile flavor components in five varieties, Bekdo, Chundo, Yumung, Daegubo and Hwangdo, of peach (Prunus persica L.) were extracted by SDE (Simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether(1:1, v/v) as an extract solvent. Analysis of the concentrate by capillary gas chromatography and gas chromatography-mass spectrometry led to the identification of 83, 85, 70, 74 and 66 components in Bekdo, Chundo, Yumung, Daegubo and Hwangdo, respectively. Aroma patterns (29 alcohols, 27 ketones, 18 aldehydes, 9 esters, 5 ethers, 3 acids, 6 terpene and derivatives, and 26 miscellaneous) were identified and quantified in five cultivars. Ethyl acetate, hexanal, o-xylene, (E)-2-hexenal, hexanol, (E)-2-hexen-1-ol, benzaldehyde, r-decalactone and r-dodecalactone were the main components in each samples, though there were several differences in composition of volatile components. Beside C$\_$6/ compounds, a series of saturated and unsaturated r- and $\delta$-lactones ranging from chain length C$\_$6/ to C$\_$l2/, with concentration maxima for r-decalactone and r-dodecalactone, were a major class of constituents. Lactones and peroxidation products of unsaturated fatty acid (i.e. C$\_$6/ aldehydes and alcohols) were major constituents of the extract.

• Biomolecules & Therapeutics
• /
• v.9 no.4
• /
• pp.285-290
• /
• 2001

Bioequivalence of two acetyl-1-carnitine tablets, test product (Carnitile tablet: Hanmi Pharm. Co., Ltd.) and reference product (Nicetil $e^{R}$ tablet: Dong-A Pharm. Co., Ltd.), was evaluated according to the guide- lines of Korea Food and Drug Administration (KFDA). Twenty-six healthy volunteers were divided randomly into two groups and administered the drug orally at the dose of 500 mg as acetyl-1-carnitine in a 2$\times$2 crossover study. Blood samples were taken at predetermined time intervals for 12 hours and the plasma concentration of acetyl-1-carnitine was determined using HPLC by derivatization with p-bromophenacyl bromide. The pearmacokinetic parameters (AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$) were calculated and ANOVA was utilized for the statistical analysis of parameters. The apparent differences of these parameters between two drugs were less than 20% (i.e., 1.26,-5.08 and 8.59% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The powers (1-$\beta$) for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, and Tmax were over 0.9. Minimal detectable difference ($\Delta$) at $\alpha$=0.05, 1-$\beta$=0.8 were less than 20% (i.e.,7.31, 14.88 and 11.77% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The confidence intervals ($\delta$) for these parameters were also within $\pm$ 20% (i.e.,-3.03$\leq$$\delta$$\leq$5.54, -13.80$\leq$$\delta$$\leq$3.64 and 1.69$\leq$$\delta$$\leq$15.48 for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). These results satisfied the criteria of KFDA guideline for bioequivalence, indicating Carnitile bioequivalent to Nicetil $e^{R}$ .TEX>$^{R}$ .> R/ . R/ .

• Microbiology and Biotechnology Letters
• /
• v.32 no.3
• /
• pp.243-248
• /
• 2004

Production of (R)-3-hydroxybutyric acid (R3HB) by fed-batch culture and continuous culture of metabolically engineered Escherichia coli harboring Ralstonia eutropha PHB biosynthesis and depolymerase genes was examined in a 30 1 pilot-scale fermentor. A new stable two-plasmid system, pBRRed containing the R. eutropha PHB depolymerase gene and pMCS 105 containing the R. eutropha PHB biosynthesis genes, was developed. Among a variety of E. coli strains harboring plasmids, recombinant E. coli XL-10 Gold (pBRRed, pMCS105) was able to produce R3HB with the highest efficiency in a batch culture. By the fed-batch culture of recombinant E. coli XL-10 Gold(pBRRed, pMCS 105) in a 30 1 fer-mentor, the final R3HB concentration was 22.4 g/l giving a productivity of 0.97 g/l-h. To produce R3HB to a high concentration with high productivity, a new strategy of fed-batch culture followed by a continuous culture was investigated. The maximum productivity and R3HB concentration were 5.06 g/l-h and 25.3 g/l, respectively. These results show that economical production of R3HB is possible by recombinant E. coli in large scale.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.7
• /
• pp.1346-1353
• /
• 2001

This paper presents an algorithm for the design of 2 dimension separable denominator digital filter(SDDF). The proposed algorithm is based on the reduced dimensional decomposition not only 2 dimension SDDF's but also of given 2 dimension specification. The frequency domain design of 2 dimension separable denominator digital filters based on the reduced dimensional decomposition can be realized when the given 2 dimension frequency specification are optimally decomposed into a pair of 1 dimension digital filter specification via singular value decomposition. the algorithm is computationally efficient and numerically stable. In case of the low pass filter, the approximation error of the proposed design algorithm is $e_{m}$=5.17, $e_{r1}$ =8.78, $e_{r2}$=7.34, while in case of band pass filter, the approximation error is $e_{m}$=13.00, $e_{r1}$=62.76, $e_{r2}$=62.7676.7676