• 전자공학회논문지A
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• 제33A권10호
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• pp.139-143
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• 1996

We report on the static and dynamic characteristics of optically modulated resonant tunneling diode oscillator (RTDO) formed in double-barrier quantum-well structure. Under the illumination of Ti:Sapphire laser, the dc current-voltage (I-V) curves of RTDO shifted towared lower voltages. This characteristic was found to odify the series resistance, negtive differential resistance, capacitance, and the inductance of the RTDO. As a result, the resonant frequency of TRDO centered at 5.302 GHz was found to decrease about 20 MHz under the laser illumination. At a constnat bias voltage, the oscillation frequency decreased linearly as the laser power was increased.

• 한국연초학회지
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• 제24권1호
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• pp.27-31
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• 2002

Three kinds of inoculation methods, capillary, root cutting and dipping were compared for an efficient way to screening the resistant tobacco variety against bacterial wilt, Ralstonia solanacearum. The pricking a capillary tube contained the pathogenic bacterial suspension(10$^{7}$ cfu/$m\ell$) to an axillary bud of each tobacco plant showed different resistance well between varieties. The less period was required in inoculating work and in disease development for the inoculation method used with capillary tube than for two other inoculation methods tested also.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.343-345
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• 2005

In comparison to general purpose step-up/down transformer, welding transformer for resistance spot welding requires strict design criteria. The major significant specifications include duty cycle, arm length and its geometric configuration(window area) as well as various current/voltage conditions and material properties. This interactive program propose new promising procedure for weldling transformer. Users can input design variables and modify in accordance with graphic Output.

• 전자공학회논문지S
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• 제35S권7호
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• pp.103-108
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• 1998

In this paper, we atempt to control the nonlinear power system for resistance spot welders to be a fully linearizesd system by applying the recently developed nonlinear feedback linearization techniques. the controller proposed in this paper is computationally simple. In addition, the easy gain tuning as well as the high dynamic performance of resistance spot welding systems can be obained simulaneously. To illustrate the dynamic performance of our controller further, we present some simulation results.

• 대한설비공학회지:설비저널
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• 제17권4호
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• pp.377-381
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• 1988

Effects of thermal resistance of mold during freezing processes have been investigated. Saturated liquid is chosen to present one-dimensional quasi-steady solution and this solution is compared with numerical solutions. Front tracking finite element method has been applied for the numerical solutions. Results show that mold should be considered as well as phase change material except the cases when the very thin mold with relatively high thermal conductivity is used.

• 대한바이러스학회지
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• 제27권1호
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• pp.77-86
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• 1997

To examine AZT resistance of HIV-1 isolates from AZT treated or untreated Korean, several biological characteristics such as syncytium formation, HIV-1 reverse transcriptase activity and the p24 antigen production in MT-2 cells infected with 4 HIV-1 isolates were determined. As controls, we tested HIV-1 HTLV-IIIB and pre-drug isolate as AZT susceptible strains, in addition to HIV-1 RTMC/MT-2 and post-drug isolate as AZT resistant strains. When the inoculum size of HIV-1 was 300 $TCID_{50}$/well and 100 $TCID_{50}$/well, the AZT susceptibility of AZT untreated HIV-1 isolates 8806 and 9571 were similar to that of HIV-1 HTLV-IIIB and AZT-susceptible HIV-1 strains. When we evaluated AZT resistance of isolates HIV-1 8812 and 9113 treated with AZT for 36 months by observation of syncytium formation, HIV-1 8812 showed resistance simillar to that of HIV-1 RTMC/MT-2 strain forming syncytium up to AZT $1{\mu}g/ml$, and HIV-1 9113 showed resistance identical with that of AZT-resistant HIV-1 strain which formed syncytium up to AZT $10\;{\mu}g/ml$. Especially, when we evaluated AZT resistance by HIV-1 reverse transcriptase activity and the p24 antigen production, HIV-1 isolates 8812 and 9113 showed much higher resistance (>10 - 200 fold) compared with HIV-1 RTMC/MT-2 and AZT-resistant HIV-1 strain.

• 한국표면공학회지
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• 제15권3호
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• pp.138-145
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• 1982

The effects of the simultaneous variations of the ratio of feed gases(H2/N2 Flow ratio), feed gas flow rate (H2/N2, total-flow rate) and partial pressures of TiCl4 (PTiCl41) as well as deposition time and cobalt content of the substrate on the deposition rate of the TiN Coated Cemented Tungsten Carbide Tools were investigated. Deposition was carried out in the temperature range of 930$^{\circ}C$-1080$^{\circ}C$ and an activation energy of 46.5 Kcal/mole can be calculated. Transverse rupture strength was noticeably reduced by the TiN coating on the virgin surfa-ce of Cemented Tungsten Carbide, the extent of which was decreased according to the coa-ting thickness. Microhardness value observed on the work was in the range of 1700∼2000kg/mm, which were in well agreement with the value of bult TiN. The wear resistance of TiN layers was performed by turning test and it was observed that crater and flank resistance remarkably enhanced by TiN coating.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.824-828
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• 2011

Transmission line analysis of the surface a cumulation layer in injection-enhanced gate transistor (IEGT) is presented for the first time, based on per-unit-length resistance and conductance of the surface layer beneath the gate of IEGT. Lateral electric field on the accumulation layer surface, as well as the electron current injected into the accumulation layer, is governed by the well-known wave equation, and decreases as an exponential function of the lateral distance from the cathode. Unit-length resistance and conductance of the layer are expressed in terms of the device parameters and the applied gate voltage. Results obtained from the experiments are consistent with the numerical simulations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.67-67
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• 2011

Compound semiconductor/CNTs composites have shown considerably improved efficiency improvement in photovoltaic devices, which is often attributed to two different factors. One is the formation of efficient electronic energy cascade structures. The other effect of CNTs on the performance of photovoltaic devices is the decrement of interfacial resistance. The interfacial resistances at n-type/ p-type materials and/or n-type materials/TCO electrode are reduced by an outstanding electrical property of CNTs. In addition to the effects of CNTs, we report the third reason for increment of efficiency in photovoltaic devices by CNT's well-known electrical field enhancement effects. The improved ${\beta}$ values in reverse-FE currents of CIGS electrode with SWNTs layers indicate the enhancement of electrical field in photovoltaic devices, which implies the acceleration of the electron transfer rate in the cell. Due to the formation of an efficient electronic energy cascade structure and the decrease of the interfacial resistance as well as the improvement of the electrical field in the photovoltaic devices, the power conversion efficiency of electrochemically deposited superstrate-type CIGS solar cells was increased 24.3% in the presence of SWNTs and showed 10.40% conversion efficiency.

• 미생물학회지
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• 제26권1호
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• pp.13-19
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• 1988

The location of R-determinants, $Ap^{r}$ and $Tc^{r}$, and replication origin in pKU41 determined using the construction of miniplasmid by the BamHI and the HindIII restriction fragment from pKU41 and the cloning of the restriction fragments from pKU41 into pSY343. The gene encoding resistance to ampicillin (Ap) as well as replication origin in pKU41 were located on the region overlapping BamHI B fragment and HindIII A fragment. The gene encoding resistance to tetracycline (Tc) was located on the region of the HindIII C fragment, which was cleaved by BamHI as well.