• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.899-900
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• 2009

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.427-432
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• 2018

High-capacity secondary batteries can cause explosion hazards owing to microcurrent variations or current surges that occur in short circuits. Consequently, complete safety cannot be achieved with general protection that is limited to a mere current fuse. Hence, in the case of secondary batteries, it is necessary for the protector to limit the inrush current in a short circuit, and to detect the current during microcurrent variations. To serve this purpose, a fuse can be employed for the secondary battery protection circuit with current detection. This study aims at designing a protection device that can stably operate in the hazardous circumstances associated with high-capacity secondary batteries. To achieve the said objective, a detecting fuse was designed from an alloy of low melting point elements for securing stability in abnormal current states. Experimental results show that the operating I-T and V-T characteristic constraints can be satisfied by employing the proposed current detecting self-contained low melting point fuse, and through the resistance of the heating resistor. These results thus verify that the proposed protection device can prevent the hazards of short circuit current surges and microcurrent variations of secondary batteries.

• 전기학회논문지
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• 제67권12호
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• pp.1619-1625
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• 2018

Portable electronic devices secondary batteries can cause fire and explosion due to micro-current change in addition to the situation of short-circuit inrush current, safety can not be secured with a general operation limited current fuse. Therefore, in secondary battery, it is necessary for the protector to satisfy both the limit current type operation in the open-short-circuit inrush current and the current detection operation characteristic in the micro current change situation and for this operation, a fuse for the current detection type secondary battery protection circuit can be applied. The purpose of this study is to design a protection device that operates stably in the hazardous situation of small capacity secondary battery for portable electronic devices through the design of low melting fuse elements alloy of sensing type fuse and secures stability in abnormal current state. As a result of the experiment, I-T and V-T operation characteristics are satisfied in a the design of the alloy of the current sensing type self-contained low melting point fuse and the resistance of the heating resistor. It is confirmed that it can prevent accidents of short circuit over-current and micro current change of secondary battery.

• 대한화학회지
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• 제11권1호
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• pp.12-16
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• 1967

?織物上의 Chlorantine Fast Red 5B(C.I. Direct Red 81)의 照光으로 因한 褪色을 檢討하여 同染料의 CF曲線의 기울기는 異例的으로 負의 기울기를 나타내는 反面 CFG 曲線의 기울기는 正의 기울기를 나타낸다는 것을 밝혀내고, 同染料의 CF曲線의 기울기가 負로 나타남에도 不拘하고 CFG曲線의 기울기는 正으로 나타나게 되는 理由를, Weber-Fechner의 法則이 染色物의 視覺에 依한 褪色判定에 作用하는 때문인 것으로 보고, 視覺判定에 依할 때의 染料의 褪色量($F_v$)은 $F_v=[logC_0-log(C_0-C_0F_t/100)]{\times}100/(logC_0+b)$ 但 $F_t$; t時間 照光後의 染料의 褪色量, $C_0$; 染料의 初濃度, b; 定數으로 表示할 수 있다는 것을 明白히 하였다. 아울러 染料濃度 增加에 따르는 日光堅牢度 上昇의 原因으로서 染料의 集合效果外에, 染料濃度가 視覺判定에 依한 褪色判定結果에 미치는 影響도 考慮해야 할것임을 明白히 하였다.

• Journal of Magnetics
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• 제14권1호
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• pp.11-14
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• 2009

We investigated the I-V curves and differential tunneling conductance of two, CoFeB/MgO/CoFeB-based, magnetic tunnel junctions (MTJs): one with a low tunneling magnetoresistance (TMR; 22%) and the other with a high TMR (352%). This huge TMR difference was achieved by different MgO sputter conditions rather than by different annealing or deposition temperature. In addition to the TMR difference, the junction resistances were much higher in the low-TMR MTJ than in the high-TMR MTJ. The low-TMR MTJ showed a clear parabolic behavior in the dI/dV-V curve. This high resistance and parabolic behavior were well explained by the Simmons' simple barrier model. However, the tunneling properties of the high-TMR MTJ could not be explained by this model. The characteristic tunneling properties of the high-TMR MTJ were a relatively low junction resistance, a linear relation in the I-V curve, and conduction dips in the differential tunneling conductance. We explained these features by applying the coherent tunneling model.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1832-1838
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• 2006

The present paper is focused on sorption concentration of silver (I) on some complex-forming ion exchangers in the initial thiocyanate form and subsequent determination of Ag(I) in the phase of anion exchanger AN-25 by diffuse reflectance spectroscopy. The sorption and kinetic characteristics of the sorbents were investigated. The apparent stability constants of thiocyanate silver complexes in the ion exchanger phase were calculated. The sorption-spectroscopic method is proposed for Ag(I) determination in aqueous solutions. The calibration curve is linear in the concentration range of 10-200 mg/L (sample volume is 10.0 mL) and the detection limit is 2 $\mu$g/mL. The presence of $Na^+,\;K^+,\;Mg^{2+}$ (macrocomponents) as well as of Ni (II), Co (II), Cu (II) do not hinder the determination of silver (I).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.295-299
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• 1996

In order to investigate the relation between the microstructure and the V-I characteristics of HTSC wire, single and 19 filamentary silver-sheathed Bi2223 tapes were fabricated using the powder-in-tube method. Higher J$\_$c/ at 77.3 K(0 T) and 4.2 K(in magnetic field) can be achieved for the 19 filamentary Bi tape, comparing the single filamentary tape. However, the I$\_$c/ distribution of 19 filamentary Bi2223 tape was found to be wider by analyzing the curve obtained from 2nd differential of V-I data. This was considered to be resulted from worse uniformity of oxide filament due to severe cold working.

• Transactions on Electrical and Electronic Materials
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• 제18권6호
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• pp.311-315
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• 2017

The perovskite system $(Ba^{2+}{_{1-x}}La^{3+}{_x})Fe^{3+}{_{1-t}}Fe^{4+}{_t}O_{3-y}$ (y = (1 - x --t)/2) having a composition of x = 0.0, 0.1, 0.2, and 0.3 showedean increase in $Fe^{4+}$ mole ratios with an increase in oxygen partial pressure ($N_2{\rightarrow}air{\rightarrow}O_2$), and with an increasefin s, the $Fe^{3+}$ quantity decreased and oxygen content (3-y value) increased. For each N sampls heat-treated in $N_2$ gas, a considerable weight gain, i.e.g a steadynincrease if oxygen content, was observed in the TGA data on the cooling process. The conductivity values at a constant temperature were in the order of $N_2$$O_2$; the respective log ${\sigma}$ values (${\Omega}^{-1}{\cdot}cm^{-1}$) at 323 K of the BL0 sample were -5.75 (BL0-N), -3.39 (BL0-A), and -0.53 (BL0-O). The mixed valencies of $Fe^{3+}$ and $Fe^{4+}$ ions in each sample were also confirmed by both the oxidation curve above 350 mV and the cathodic reduction curve below 200 mV from cyclic voltammetry.

• 한국산업정보학회논문지
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• 제17권7호
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• pp.51-57
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• 2012

본 논문에서는 안전한 V2V 통신과 V2I 통신을 보장하는 ECDH(Elliptic Curve Diffie Hellman) 기반 그룹키를 제안하였다. 본 논문에서 제안하는 ECDH기반 그룹키는 AAA 서버를 사용하지 않고 차량과 차량사이의 그룹키인 VGK(Vehicular Group Key), 차량 그룹 사이의 그룹키인 GGK(Globak Group Key), 그리고 차량과 RSU사이의 그룹키인 VRGK(Vehicular and RSU Group Key)를 ECDH 알고리즘을 이용하여 생성한다. 차량과 RSU 사이의 그룹키인 VRGK는 현재 RSU에서 다음 RSU에게로 RGK(RSU Group Key)로 암호화하여 안전한 채널을 통하여 전달하기 때문에 완벽한 순방향 기밀(Perfect Forward Secrecy) 보안 서비스가 제공된다. 또한, 메시지를 전송한 차량이 해당 그룹의 구성원인지를 그룹키 이용하여 확인함으로써 Sybil공격을 탐지할 수 있다. 그리고 그룹간의 안전한 통신으로 불필요한 네트워크 트래픽이 발생하지 않으므로 메시지 전송 시간 및 서버의 오버헤드를 줄일 수 있다.

• Archives of Pharmacal Research
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• 제26권9호
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• pp.763-767
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• 2003

The differences in pharmacokinetic behavior and tissue distribution of verapamil and its enantiomers were investigated in rats. In high-performance liquid chromatographic method, an achiral ODS column (150 mm $\times$ 4.6 mm i.d.) with the mobile phase consisting of methanol-water (73:30, v/v) was used for the determination of the concentration for racemic verapamil, and a Chiralcel OJ column (250 mm$\times$4.6 mm i.d.) with the mixture of n-haxane-ethanol-triethylamine (85:15:0.2, v/v/v) as mobile phase was used to determine the concentrations of verapamil enantiomers. A fluorescence detector in the analytical system was set at excitation and emission wavelengths of 275 nm and 315 nm. The differences between enantiomers were apparent in the pharmacokinetics in rats. The area under the concentration-time curve (AUC) of S-(-) verapamil was higher than that of R-(+) verapamil. The half-distribution time ($T_{1/2(\alpha)}$) of S-(-) verapamil which distributing to tissue from blood was shorter than that of R-(+) verapamil, but the elimination half-time ($T_{1/2(\beta)}$) was longer in rat following oral administration of racemic verapamil. At 1.3 h after oral administration of racemic verapamil, however, there were no significant differences between enantiomers for the distributions in major tissues such as heart, cerebrum, cerebellum, liver, spleen and kidney.