• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.867-869
• /
• 2000

This paper describes the steady state performance of a self-excited wound type induction generator with stator and rotor windings connected in series along with excitation capacitors. For this purpose a mathematical model is developed by means of the well known generalized machine theory utilizing d-q axis orthogonal transformation. This model can be used to analyze short shunt and long shunt generators as well as shunt generator and the algorithm for this analysis is persented. The characteristics of generators are compared one another by using parameters which are validated by Mostafa et al.

• Journal of Plant Biology
• /
• v.5 no.3
• /
• pp.30-36
• /
• 1962

The mechanism of synthesis of the toacco mosaic virus(TMV) and the potato virus X(PVX) was investigated using the methods of ultraviolet light irradiation and serological analysis. In vitro irradiation of UV on the infected tobacco juice for 10 minutes caused the infectivity of TMV and PVX to decrease markedly on their respective local lesion indicator hosts, Nicotiana glutinosa L. and Gomphrena globosa L., indicating that UV destroys directly the infectivity of the virus particles. Ten minutes after the UV was irradiated on the leaves of the two indicator hosts before inoculation, the infectivity of TMV decreased as it was irradiated in vitro, whereas that of PVX increased by 26% as compared with the unirradiated control. When the two viruses were mix-inoculated in the common host of tobacco and the synthetic products were analyzed by serological methods for a two week infection period, it was found that both viruses were multiplying more rapidly and abundantly than they were singly inoculated into the same host species. Titers from mixed series were often two times as high as those of singly inoculated series. A mechanism of competition in the synthesis between the mixed viruses in the common host is postulated.

• YAKHAK HOEJI
• /
• v.43 no.6
• /
• pp.762-770
• /
• 1999

A series of vitamin-containing Pt(II) complexes of the type [Pt (FMN) (L)] (FMN=flavin mononucleotide, L=ethylenediamine, 1,3-propanediamine, 1,4-bu-tanediamine) was synthesizd and characterized by IR, electronic absorption, elemental analysis and FAB=Mass. The coordination sites of FMN to Pt(II) ions were determined to be N(5) and O(6) with resultant chelate ring formation. Theses compounds have much better water solubility (30-35 mg/ml) than cisplatin (1 mg/ml). The anticancer activity of this vitamin-containing Pt(II) series was investigated by MTT assay against mouse and human leukemia cell lines in vitro. Among these compounds, FMN (1,4-butanediamine) Pt(II) having seven-membered ring structure as amine ligand showed moderate anticancer activity.

• Bulletin of the Korean Chemical Society
• /
• v.20 no.7
• /
• pp.777-780
• /
• 1999

N-Chloroacetyl-N-hydroxy- β-Phe-NHMe and N-chloroacetyl-N-hydroxy-α-Phe-OMe were designed, synthe-sized and evaluated as irreversible inhibitors of thermolysin, a representative zinc protease. Analysis of kinetic data of the enzymic activity of thermolysin in the presence of these inhibitors revealed that they are indeed potent inactivators of thermolysin having the k(inact)/K(I ) values of 3.06 and 0.05 M (-1) s(-1) , respectively. We have established that the inhibitory activity of N-chloroacetyl-N-hydroxy-β-Phe-NHMe stems mainly from the (R)-enantiomer that belongs to the "L" series. The (R)-enantiomer is also responsible for the inactivation in the case of N-chloroacetyl-N-hydroxy-α-Phe-OMe, but this enantiomer belongs to the "D"-series.

• Steel and Composite Structures
• /
• v.9 no.4
• /
• pp.367-380
• /
• 2009

This study focuses on the experimental evaluation of the flexural-torsional performance of high strength thin-walled composite members. A series of tests on composite members with various sectional aspect ratios subjected to eccentric cyclic loads were conducted. Test results show that the composite member's torsional strength could be approximated using a series of linear segments and evaluated using the superposition of the component steel and reinforced concrete responses. It is also validated from the tests that the strength deterioration of members subjected to combined loads is closely related to the aspect ratios of the sections. An interaction expression between the bending and torsion for high strength thin-walled composite members is proposed for engineering practice references.

• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.1114-1118
• /
• 1992

This paper deals with the analysis of the electronic ballast which is based on half-bridge type series inverters. First, design basis was described for the determination of the values, L and C. Next, the operation of the electronic ballast was analyzed theoritically. Finally. the digital simulations and experiments were carried out to prove the obtained theoritical results.

• Communications of the Korean Mathematical Society
• /
• v.12 no.4
• /
• pp.895-904
• /
• 1997

Let B(z) be a power series with operator coefficients where multiplication by B(z), T, is a contractive and everywhere defined transforamtion in the square summable power series. Then there is a Julia operator U for T such that $$ U = (T D)(\tilde{D}^* L) \in B(H \oplus D, K \oplus \tilde{D}), $$ where D is the state space of a conjugate canonical linear system with transfer function B(z).

• Wind and Structures
• /
• v.3 no.3
• /
• pp.159-175
• /
• 2000

Many practical time series, including pressure signals measured on roof-corners of low-rise buildings in quartering winds, consist of relatively quiescent periods interrupted by intermittent transients. The dyadic wavelet transform is used to detect these transients in pressure time series and a relatively simple pattern classification scheme is used to detect underlying structure in these transients. Statistical analysis of the resulting pattern classes yields a library of signal "building blocks", which are useful for detailed characterization of transients inherent to the signals being analyzed.

• Bulletin of the Korean Mathematical Society
• /
• v.44 no.2
• /
• pp.351-358
• /
• 2007

For an entire function f whose Fourier transform has a compact support confined to $[-{\pi},\;{\pi}]$ and restriction to ${\mathbb{R}}$ belongs to $L^2{\mathbb{R}}$, we derive a nonuniform sampling theorem of Lagrange interpolation type with sampling points ${\lambda}_n{\in}{\mathbb{R}},\;n{\in}{\mathbb{Z}}$, under the condition that $$\frac{lim\;sup}{n{\rightarrow}{\infty}}|{\lambda}_n-n|<\frac {1}{4}$.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1996.10a
• /
• pp.12-17
• /
• 1996

The structure formation by liquid-liquid(L-L) phase separation coupled with crystallization in isotactic polypropylene(i-PP). solutioos was investigated by a temperature jump experiment. A series of dialkyl phthalates with a different number of carbon atoms in the alkyl chain was used to control the interaction between polymer and solvent. Various thermal quench conditions were applied to the i-PP solutions to control systematically L-L phase separation and crystallization. A slow crystallizatina elongates the liquid droplets in the radial direction of a spherulite. A rapid crystallization under the deep quench locks-in the growth of L-L phase separation. These results indicate that the extent of L-L phase separation which exists below melting point can be successfully controlled through the proper selection of solvent and thermal conditions.