• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2311-2316
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• 2010

Three series of copolyterephthalamides having biphenyl-2,2'-diyl structure in the main chain, were synthesized from p-phenylene-containing diamines such as p-phenylene diamine, 4,4'-oxydianiline or 1,4-bis(4-aminophenoxy)benzene, with mixed diacids of terephthalic acid and 2,2'-bibenzoic acid by the direct polycondensation method. The resulting copolymers had inherent viscosities ranging from 0.46 to 0.93dL/g, and most of them could be readily dissolved in polar aprotic solvents including N,N-dimethyl acetamide and N-methyl-2-pyrrolidone. These copolymers had glass transition temperatures between 239 and $326^{\circ}C$, and their 10% weight loss temperatures were recorded in the range of $410{\sim}485^{\circ}C$ in nitrogen atmosphere.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.441-448
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• 1986

Dioxobis(sub.-salicylaldiminato) molybdenum (VI) complexes, $MoO_2\;(X-sal-N-R)_2,\;(X=H,\;5-CH_3,\;R=C_6H_5,\;p-F-C_6H_4,\;m-Cl-C_6H_4,p-I-C_6H_4\;and\;p-C_2H_5-C_6H_4)$, have been prepared by reactions of dioxobis(sub.-salicylaldehydato) molybdenum (VI), $MoO_2(X-sal)_2$ with primary amines, in which $MoO_2(X-sal)_2$ complexes were obtained by acidification of a mixture solution of ammonium paramolybdate in water and appropriate salicylaldehyde in methanol. All these complexes show two strong Mo=O stretching imodes in the 900-940$cm^{-1}$ and p.m.r. spectra exhibited only one signal for the azomethine group. These results confirmed that the complexes are six-coordinated octahedron with a $cis-MoO_2$ group and the geometrical configurations of the complexes possess a C2 axis of symmetry. From the mass analyses of the complexes, it found that the composition ratios of $MoO_2$ : ligand are 1 : 2. The charge transfer transition corresponding to N-Mo, and O-Mo occured at 29,000$cm^{-1}$ and 32,000$cm^{-1}$ respectively. Where, the complexes were found to be non-ionic materials by conductivity measurements in dimethylformamide.

• Communications of the Korean Mathematical Society
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• v.26 no.2
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• pp.197-205
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• 2011

Explicit sufficient conditions are established for the oscillation of the one order neutral differential equations with impulsive $(x(t)+{\sum\limits^n_{i=1}}c_ix(t-{\sigma}_i))'+px(t-{\tau})=0$, $t{\neq}t_{\kappa}$, ${\Delta}(x(t_{\kappa})+{\sum\limits^n_{i=1}}c_ix(t_{\kappa}-{\sigma}_i))+p_0x(t_{\kappa}-{\tau})=0$, $c_i{\geq}0$, $i=1,2,{\ldots}n$, $p{\tau}$>0, $p_0{\tau}$>0, ${\Delta}(x_{\kappa})=x(t^+_{\kappa})-x(t_{\kappa})$. Explicit sufficient and necessary condition are established when $c_i$ = 0, i = 1, 2, ${\ldots}$, n.

• Journal of Applied and Pure Mathematics
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• v.5 no.1_2
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• pp.41-53
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• 2023

Let G = (V, E) be a (p, q) graph. Define $${\rho}=\{{\frac{2}{p}},\;{\text{{\qquad} if p is even}}\\{\frac{2}{p-1}},\;{{\text{if p is odd}}$$ and L = {±1, ±2, ±3, … , ±ρ} called the set of labels. Consider a mapping f : V ⟶ L by assigning different labels in L to the different elements of V when p is even and different labels in L to p-1 elements of V and repeating a label for the remaining one vertex when p is odd.The labeling as defined above is said to be a pair difference cordial labeling if for each edge uv of G there exists a labeling |f(u) - f(v)| such that ${\mid}{\Delta}_{f_1}-{\Delta}_{f^c_1}{\mid}{\leq}1$, where ${\Delta}_{f_1}$ and ${\Delta}_{f^c_1}$ respectively denote the number of edges labeled with 1 and number of edges not labeled with 1. A graph G for which there exists a pair difference cordial labeling is called a pair difference cordial graph. In this paper we investigate pair difference cordial labeling behaviour of Petersen graphs P(n, k) like P(n, 2), P(n, 3), P(n, 4).

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.2
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• pp.72-75
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• 2006

A CMOS compatible Super Junction LDMOS (SJ-LDMOS) structure, which reduces substrate-assisted depletion effects, is reported. The proposed structure uses a N-buffer layer between the pillars and P-substrate to achieve global charge balance between the pillars, the N-buffer layer and the P-substrate. The new structure features high breakdown voltage, low on-resistance, and reduced sensitivity to doping imbalance in the pillars.

• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.52-62
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• 2019

Objectives : The objective of this study was to investigate the effects of Zingiberis Rhizoma Pharmacopuncture(ZP) at GB30 and ST36 in neuropathic pain induced SD rats by the block of Transient Receptor Potential Vanilloid 1(TRPV1). Methods : Neuropathic pain in rats was induced by tibial and common peroneal nerve transection of right leg. The rat subjects were divided into 6 groups : normal(Nor, n=5), control(Con, n=5), neuropathic pain plus 2 mg/kg ZP injection at GB30 and ST36(ZP-A, n=5), 10 mg/kg ZP(ZP-B, n=5), 20 mg/kg ZP(ZP-C, n=5) and 0.45 mg/kg Tramadol(Tra, n=5). Three days after the surgery, injections were administered once a day for 17 days. Withdrawal response of neuropathic rats' legs were measured by stimulating the paw of Right leg with von frey filament, acetone and radient heat on day 3, 7, 11, 15, 19 after surgery. After all treatments were completed, c-Fos in the midbrain central gray and TRPV1 & TRPA1 of DRG(L5) were analyzed. Results : Groups ZP-B and ZP-C showed a meaningful decrease in the withdrawal response of mechanical allodynia, thermal hyperalgesia and cold allodynia compared to the control group(p<0.05, p<0.01, p<0.001). Groups ZP-B and ZP-C showed a meaningful decrease in the expression of c-fos and TRPV1 protein level compared to the control group(p<0.05, p<0.01, p<0.001). Conclusions : These results suggest that Zingiberis Rhizoma Pharmacopuncture at GB30 and ST36 could decrease mechanical & cold allodynia and thermal hyperalgesia by block the TRPV1 on the model of neuropathic pain.

• Communications of the Korean Mathematical Society
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• v.27 no.3
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• pp.483-488
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• 2012

In this paper we introduce the notion of P-strongly regular near-ring. We have shown that a zero-symmetric near-ring N is P-strongly regular if and only if N is P-regular and P is a completely semiprime ideal. We have also shown that in a P-strongly regular near-ring N, the following holds: (i) $Na$ + P is an ideal of N for any $a{\in}N$. (ii) Every P-prime ideal of N containing P is maximal. (iii) Every ideal I of N fulfills I + P = $I^2$ + P.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.56-61
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• 1997

I $n_{0.53}$G $a_{0.47}$As/I $n_{0.52}$A $l_{0.48}$As pseudomorphic high electron mobility transistor (P-HEMT) structures were grown on semi-insulating InP substrates by molecular beam epitzxy method. The hall effect measuremetn was used to measure the electrical properties and the photoluminescence (PL) measurement was used to measure the electrical properties and the photoluminescence(PL) measurement for optical propety. By the cross-sectional transmission electron microscopy (XTEM) investigation of the V and X shape defects including slip with angle of 60.deg. C and 120.deg. C to surface in the sampel, the defects formation mecahnism in the I $n_{0.52}$A $l_{0.48}$As epilayers on InP substrates could be explained with the different thermal expansion coefficients between I $n_{0.52}$A $l_{0.48}$As epilayers and InP substrate.d InP substrate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.160-160
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• 2010

In this work, we investigate ohmic contacts to p-type GaN using a Pt/Cu/Au metallization scheme in order to achieve low resistance and thermally stable ohmic contact on p-GaN. An ohmic contact formed by a metal electrode deposited on a highly doped InGaN/GaN superlattice sturucture on p-GaN layer. The specific contact resistance is $1.56{\times}10^{-6}{\Omega}cm^2$ for the as-deposited sample, $1.35{\times}10^{-4}{\Omega}cm^2$ for the sample annealed at $250^{\circ}C$ and $6.88{\times}10^{-3}{\Omega}cm^2$ for the sample annealed at $300^{\circ}C$.

• Bulletin of the Korean Mathematical Society
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• v.55 no.6
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• pp.1773-1781
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• 2018

The Radon transform introduced by J. Radon in 1917 is the integral transform which is widely applicable to tomography. Here we study the discrete version of the Radon transform. More precisely, when $C({\mathbb{Z}}^n_p)$ is the set of complex-valued functions on ${\mathbb{Z}}^n_p$. We completely determine the subset of $C({\mathbb{Z}}^n_p)$ whose elements can be recovered from its Radon transform on ${\mathbb{Z}}^n_p$.