• Journal of the Korean Ceramic Society
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• v.25 no.6
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• pp.645-654
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• 1988

The microstructure and electrical characteristics of ZnO-Bi2O3 ceramics containing 5mol% Bi2O3 have been studied in relation to sintering temperature and mode. The distribution and thickness of Bi2O3 intergranular layer was varied with sintering temperature and mode. Intergranular layer was more homogeneous with increasing sintering temperature, when sintering by direct heating and rapid cooling mode showed the best distribution of intergranular layer. These microstructural changes affected electrical characteristics directly, at 140$0^{\circ}C$ and C mode obtained high value of electrical resistivity and nonlinear exponent. Varistor voltage decreased with increasing sintering temperature, increased with decreasing holding time at high temperature. Barrier voltage obtained by calculation was about 1.5V.

• Korean Journal of Materials Research
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• v.6 no.6
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• pp.555-560
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• 1996

The vibrational behavior and the molecular dynamics of the high Tc superconductor Ba0.6K0.4BiO3 have been studied experimentally and by atomistic computer simulation methods. For Ba0.6K0.4BiO3, the vibrational spectrum is dominated by oxygen ion modes from 150cm-1 to 820cm-1 including infrared absorption bands at 330, 480, 640 and 830cm-1including infrared absorption bands at 330, 480, 640 and 830cm-1at room temperature. Band assignments are discussed in relation to those bands predicted by simulations, and the infrared and Raman measurements reported in the literature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.175-179
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• 1996

Ferroelectric SrBi$_2$Ta$_2$$O_{9}$ thin films were fabricated by tole Sol-Gel method using a spin-on coating with MOD(Metal Organic Dccomposition) solution on Pt/Ti/SiO$_2$/Si(100) substratcs. The films were anncalcd at 80$0^{\circ}C$ for one hour in oxygen atmosphere. The effects of Bi/Ti mole ratios on crystalline orientations, surface morphologies, and subface composition SBT thin films with a Bi/Ta mole ratios from 1.1 to 1.3 were investigated using X-ray Diffractometry (XRD). Atomic Force (AFM), X-Ray Photoelectron Spectroscopy(XPS). Ferroelectric properties of these films were also measured.d.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.1
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• pp.1-7
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• 2010

Interfacial reaction characteristics of a Bi-10Cu-20Sb-0.3Ni Pb-free alloy on Cu pad was investigated by reflow soldering at $430^{\circ}C$. The thickness of interfacial reaction layers with respect to the soldering time was also measured. After the reflow soldering, it was observed that a $(Cu,Ni)_2Sb$, a $Cu_4Sb$ intermetallic layer, and a haze layer, which is consisted of Bi and $Cu_4Sb$ phases, were successively formed at the Bi-10Cu-20Sb-0.3Ni/Cu interface. The total thickness of the reaction layers was found to be linearly increased with increasing of the reflow soldering time up to 120 s. As the added Ni element did not participate in the formation of the thickest $Cu_4Sb$ interfacial layer, suppression of the interfacial growth was not observed.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1112-1116
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• 1999

Thermoelectric effects on the temperature changes at the solid- and liquid-phase and its interface were studied by using the unidirectional solidification of $\textrm{Bi}_{2}\textrm{Te}_{3}$. Cooling or heating effects measured with current density. polarity and current passing time were quite different. By separating sole Peltier, Thomson and Joule heat theoretically and experimentally, the Peltier coefficient at the solid/liquid interface of $\textrm{Bi}_{2}\textrm{Te}_{3}$ was -1.10$\times\textrm{10}^{-1}$V, and the Thomson coefficients of solid- and liquid-phase were 7.31\times\textrm{10}^{-4}V/K, 5.77\times\textrm{10}^{-5}V/K, respectively. When D.C. passed from solid-phase to liquid-phase during the crystal growth of $\textrm{Bi}_{2}\textrm{Te}_{3}$ the crystal with more directionality was obtained owing to increase of the temperature gradient in liquid by the Peltier cooling. But in reverse current direction, the crystallinity was not changed significantly.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.522-531
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• 2003

Samples with the nominal composition, B $i_{1.84}$P $b_{0.34}$S $r_{1.91}$C $a_{2.03}$C $u_{3.06}$ $O_{10+{\delta}}$ high- $T_{c}$ superconductors containing MgO as an additive were fabricated by a solid-state reaction method. Samples with MgO of 5~30 wt% each were sintered at 820~86$0^{\circ}C$ for 24 hours. The structural characteristics, critical temperature, grain size and image of mapping with respect to MgO contents were analyzed by XRD(X-Ray Diffraction), SEM(Scanning Electron Microscope) and EDS(Energy dispersive X-ray spectrometer) respectively. As MgO contents increased, intensity of MgO Peaks and ratio of Bi-2212 phase in superconductors intensified and the proportion of the phase transition from Bi-2223 to Bi-2212 was increased.

• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.47-54
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• 2023

For Bengali music emotion classification, deep learning models, particularly CNN and RNN are frequently used. But previous researches had the flaws of low accuracy and overfitting problem. In this research, attention-based Conv1D and BiGRU model is designed for music emotion classification and comparative experimentation shows that the proposed model is classifying emotions more accurate. We have proposed a Conv1D and Bi-GRU with the attention-based model for emotion classification of our Bengali music dataset. The model integrates attention-based. Wav preprocessing makes use of MFCCs. To reduce the dimensionality of the feature space, contextual features were extracted from two Conv1D layers. In order to solve the overfitting problems, dropouts are utilized. Two bidirectional GRUs networks are used to update previous and future emotion representation of the output from the Conv1D layers. Two BiGRU layers are conntected to an attention mechanism to give various MFCC feature vectors more attention. Moreover, the attention mechanism has increased the accuracy of the proposed classification model. The vector is finally classified into four emotion classes: Angry, Happy, Relax, Sad; using a dense, fully connected layer with softmax activation. The proposed Conv1D+BiGRU+Attention model is efficient at classifying emotions in the Bengali music dataset than baseline methods. For our Bengali music dataset, the performance of our proposed model is 95%.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.95-99
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• 1993

Peroxidase activity of cytochrome P-450 was examined using N, N-dimethylaniline (NDA) as a substrate and cumene hydroperoxide (CHP) as an oxidant. The initial rates of the N-demethylation for varied concentrations of NDA (0.05-0.5 mM) by P-450 at different fixed concentrations of CHP (0.02-0.2 mM) were determined. The results suggest that P-450 proceeds its peroxidative reaction by the rapid equilibrium random bi bi mechanism to form a ternary complex with substrate and oxidant as an active intermediate.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.150-151
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• 2002

In recent years, semi-metallic Bismuth (Bi) has attracted significant attention due to very large magnetoresistance (MR) at room temperature originating from long carrier mean free path l and small effective carrier mass m＊[1, 2]. In particular, the MR behavior and long carrier mean free path l in Bi thin films can be exploited for spintronic devices, e.g. magnetic field sensors and spin-valve transistors. In present work, we present the magnetotransport properties of the electroplated and sputtered Bi thin films in the temperature range 4-300 K. (omitted)

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.229-233
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• 2019

Pure $BiFeO_3$ (BFO) and (Eu, V) co-doped $Bi_{0.9}Eu_{0.1}Fe_{0.975}V_{0.025}O_{3+{\delta}}$ (BEFVO) thin films were deposited on $Pt(111)/Ti/SiO_2/Si(100)$ substrates by chemical solution deposition. The effects of co-doping were observed by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). The electrical properties of the BEFVO thin film were improved as compared to those of the pure BFO thin film. The remnant polarization ($2P_r$) of the BEFVO thin film was approximately $26{\mu}C/cm^2$ at a maximum electric field of 1,190 kV/cm with a frequency of 1 kHz. The leakage current density of the co-doped BEFVO thin film ($4.81{\times}10^{-5}A/cm^2$ at 100 kV/cm) was two orders of magnitude lower than of that of the pure BFO thin film.