• 전기의세계
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• v.29 no.2
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• pp.111-117
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• 1980

Contacts formed by vacuum evaporation of As-Te-Si-Ge chalcogenide glass onto Al metal (99.9999%) are studied by measuring paralle capacitance C(V), Cp(w), resistance R(V), Rp(w), and I-V characteristics. The fact that contact metal alloying produced high-resistance region is confirmed from the measurements of parallel capacitance and resistance. From the I-V characteristics in the pre-switcing region, it is found that electronic conduction and sitching occurs in the vicinity of metal-amorphous semiconductor interface. From the experimental obsevations, it is concuded that the current flow in the thin film is space-charge limited current (SCLC) due to the tunneling of electrons through the energy barriers.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.227-231
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• 1996

The reflection spectrum of a $2H-PbI_2$ single crystal grown by vapour phase method were measured at 10 K near the fundamental absorption edge. The n= 1,2,3 Wannier exciton series and $A_{EP}$ reflection line were obtained from the reflection spectrum. Based on the 2nd phonon energy in the Raman spectrum, which is different from Nagamune's report, we suggest that $A_{EP}$ line is due to the bound state between the n=2 exciton and the 2nd phonon which surmise that this is LO phnon due to the second Raman process. The L-T splitting energy of n=1 exciton line was 6.56 meV and was consistent with the emission spectrum. The temperature dependence of the reflection spectrum showed that n=1 exciton peak was shifted to longer wavelength while, as the temperatre is raised, the sharpness of that with the increase of the L-T splitting energy decrease. From Wannier exiton series, the exciton binding energy and exciton radius was 30 meV and 14$\AA$, respectively.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.800-806
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• 1997

The behavior of de levels in rapid thermal annealed Fe-doped semi-insulating InP(100) was studied by photoinduced current transient spectrocopy(PICTS). In bulk InP, T2(Ec-0.24 eV), T3(Ec-0.30 eV) and T5(Ec-0.62 eV) traps were observed. After annealing the T2 trap was annihilated at 20$0^{\circ}C$ and recreated at 35$0^{\circ}C$. T3 trap was not affected below 40$0^{\circ}C$. With increasing temperature the concentration of T5 trap reduced and it was annihilated at 30$0^{\circ}C$. However the T1(Ec-0.16 eV) and T4(Ec-0.42 eV) traps were began to appear at 40$0^{\circ}C$and these concentrations were increased with annealing temperature. The T1 and T4 traps seem to be related to the isolated phosphorus vacancy( $V_{p}$) and $V_{p}$-indium antisite( $V_{p}$- $P_{in}$ ) or $V_{p}$-indium interstitial( $V_{p}$-I $n_{I}$) respectiely.respectiely.

• Kyungpook Mathematical Journal
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• v.56 no.1
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• pp.69-81
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• 2016

For a positive integer k, a k-rainbow dominating function of a digraph D is a function f from the vertex set V (D) to the set of all subsets of the set $\{1,2,{\ldots},k\}$ such that for any vertex $v{\in}V(D)$ with $f(v)={\emptyset}$ the condition ${\cup}_{u{\in}N^-(v)}$ $f(u)=\{1,2,{\ldots},k\}$ is fulfilled, where $N^-(v)$ is the set of in-neighbors of v. A set $\{f_1,f_2,{\ldots},f_d\}$ of k-rainbow dominating functions on D with the property that $\sum_{i=1}^{d}{\mid}f_i(v){\mid}{\leq}k$ for each $v{\in}V(D)$, is called a k-rainbow dominating family (of functions) on D. The maximum number of functions in a k-rainbow dominating family on D is the k-rainbow domatic number of D, denoted by $d_{rk}(D)$. In this paper we initiate the study of the k-rainbow domatic number in digraphs, and we present some bounds for $d_{rk}(D)$.

• Journal of applied mathematics & informatics
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• v.41 no.2
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• pp.321-330
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• 2023

Let G = (V, E) be a graph. Consider the group S₃. Let g : V (G) → S₃ be a function. For each edge xy assign the label 1 if ${\lceil}{\frac{o(g(x))+o(g(y))}{2}}{\rceil}$ is odd or 0 otherwise. g is a group S₃ mean cordial labeling if |v_g(i) - v_g(j)| ≤ 1 and |e_g(0) - e_g(1)| ≤ 1, where vg(i) and e_g(y)denote the number of vertices labeled with an element i and number of edges labeled with y (y = 0, 1). The graph G with group S₃ mean cordial labeling is called group S₃ mean cordial graph. In this paper, we discuss group S3 mean cordial labeling for star related graphs.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.136-142
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• 1997

An/n-GaAs(100) Schottky barrier diode has been investigated by using electoreflectance(ER). From the observed Franz-Keldysh oscillatins(FKO), the internal electric field(Ei) of the sample is $5.76\times 10^{4}$V/cm at 300 K. As the modulation voltage($V_{ac}$) IS changed, the line shape of ER signal does not change but its amplitude various linerly. For increasing forward and reverse dc bias boltage($V_{bias}$), the amplitude of ER signal decreases. The internal electric field decreased from $19.3\times 10^4\sim4.39\times10^4$V/cm as $V_{bias}$ INCREASES FROM -5.0 V TO 0.6 V. For Au/n-GaAs the valve of built-in voltage($V_{bi}$) determined from the plot of $V_{bias}$ versus $E_i^2$ is 0.70 V. This value agrees with that observed in the plot of $V_{bias}$ versus amplitude of FKO peak. In addition, the carrier concentraion(N) and potential barrier($\Phi$) of the sample at 300 K are found to be about $2.4\times 10^{16}\textrm{cm}^{-3}$ and 0.78 eV, respectively.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.2
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• pp.149-154
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• 1999

The effect of Yukilsunki-tang extracts on global cerebral ischemia were investigated in this study. The multiple parameters of global cerebral ischemia assessed in mice included the duration of KCN-induced(1.8mg/kg i.v.) coma, the survival time of KCN-induced(3.0mg/kg i.v.) coma, the survival time exposed to hypoxia induced by vacuum pump. In the case of global cerebral ischemia International Cancer Research mice were used and divided into two groups at random Group A, normal control, was treated after oral administration of normal saline. Group B, experimental control, was treated after oral administration of 13.2mg/20g of Yukilsunki-tang extracts. Each treatment was KCN-induced(1.8mg/kg i.v.) coma, KCN-induced(3.0mg/kg i.v.) coma and exposure to hypoxia induced by vacuum pump. The results were obtained as follows ; In global cerebral ischemia, Yukilsunki-tang extracts significantly prolonged the duration of KCN-induced(1.8mg/kg i.v.) coma, the survival time of KCN-induced(3.0mg/kg i.v.) coma and the survival time of exposure to hypoxia induced by vacuum pump in mice. Conclusion Yukisunki-tang extracts had a significant effect on Global cerebral ischemia.

• The Korean Journal of Pharmacology
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• v.15 no.1_2 s.25
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• pp.7-12
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• 1979

Employing clonidine, phenoxybenzamine, and phentolamine, the author attempted to clarify the mechanism of the pressor response in raised intracranial pressure (ICP) in urethaneanesthetized rabbits. Intravenous clonidine inhibited the pressor response in raised ICP as intraventricular (I.V.T ) clcnidine did. Intravenous phenoxybenzamine and phentolamine weakened markedly the pressor response in raised ICP I.V.T. phenoxybenzamine did not affect the pressor response as I.V.T. phentolamine. I.V.T. phenoxybenzamine antagonized the inhibitory effect of I.V.T. clonidine on the pressor response as I.V.T. phentolamine. It is concluded that the central and peripheral sympathetic activity plays an important role in producing the pressor response in raised ICP.

• Korean Journal of Veterinary Research
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• v.42 no.1
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• pp.35-43
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• 2002

Cryopreservation is commonly used for an efficient utilization of semen, oocytes and embryos but has disadvantage in the survival, development of the post-thawed eggs. The high risk in the survival, development of eggs after thawing is thought to be caused by inappropriate internal regulation of $Ca^{2+}$ and/or formation of intracellular ice crystals. In this experiment, we tested whether the $Ca^{2+}$ current (iCa), a decisive factor to $Ca^{2+}$ entry, was altered in post-thawed oocytes by using whole cell voltage clamp technique. The quality and survival rates of the oocytes derived from both fresh and frozen groups were examined by morphology and FDA-test. Vitrified oocytes (VOs) were incubated for 4 hr after thawing and then donated to this experiment. Ethyleneglycol-ficoll-galactose (EFG) was used as a cryoprotectant for vitrification. The membrane potential was held at -80 mV and step depolarizations of 250 ms were applied from -50 mV to 50 mV in 10 mV increments. The survival rates showed a higher in VOs vitrified with EFG containing $Ca^{2+}$ than in VOs vitrified with EFG under the $Ca^{2+}$-free condition (82.0% vs 14%). In group with/without $Ca^{2+}$, the survival rates were significantly (P<0.01) difference. In the fresh metaphase II oocytes (FOs), current-voltage (I-V) relationship showed that iCa began to activate at -40 mV and reached its maximum at -10 mV. With same voltage pulses, inward currents were elicited in VOs. I-V relationships observed in VOs were similar to those in FOs. Time constants of activation and inactivation of the inward current shown in VOs were not different to those in FOs. This accordance in I-V relations and time constants in FOs with those in VOs indicates that the inward currents in FOs are unaltered by vitrification and thawing. Therefore, vitrification with EFG does not play as a factor to deteriorate $Ca^{2+}$ entry across the membrane of the oocytes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.5
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• pp.368-373
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• 2010

In this study, we have investigated the effects of Cr dopant on the bulk trap levels and grain boundary characteristics of $Bi_2O_3$-based ZnO (ZB) varistor using admittance spectroscopy and dielectric functions (such as $Z^*,\;Y^*,\;M^*,\;{\varepsilon}^*$, and $tan{\delta}$). Admittance spectra show more than two bulk traps of $Zn_i$ and $V_o$ probably in different ionization states in ZnO-$Bi_2O_3-Cr_2O_3$ (ZBCr) system. Three kinds of temperature-dependant activation energies ($E_{bt}'s$) were calculated as 0.11~0.14 eV of attractive coulombic center, 0.16~0.17 eV of $Zn_{\ddot{i}}$, and 0.33 eV of $V_o^{\cdot}$ as dominant bulk defects. The grain boundaries of ZBCr could be electrochemically divided into two types as a sensitive to ambient oxygen i.e. electrically active one and an oxygen-insensitive i.e. electrically inactive one. The grain boundaries were electrically single type under 460 K (equivalent circuit as parallel $R_{gb1}C_{gb1}$) but separated as double one ($R_{gb1}C_{gb1}-R_{gb2}C_{gb2}$) over 480 K. It is revealed that the dielectric functions are very useful tool to separate the overlapped bulk defect levels and to characterize the electrical properties of grain boundaries.