• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.5
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• pp.640-645
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• 2012

DC-DC converter and DC-AC inverter in a hybrid electric vehicle (HEV) generate the switching noise. It may be generated by the reverse recovery operation of the power diode in the switching circuit of the converter or the inverter. The shape of the reverse recovery region may be determined by both reverse time and recovery time in the diode. So, in this paper, the frequency spectrum of switching noise was estimated by the shape of the reverse recovery region and compared with the measured results. It shows that the meaningful region of the frequency spectrum is directly related with the reverse time.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1308-1313
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• 2004

Proton irradiation technology was used for the improvement of power diode switching characteristics. Proton irradiation was carried out at the energies of 2.32 MeV, 2.55 MeV, 2.97 MeV so that the projection range of irradiated proton would be at the metallurgical junction, depletion region and neutral region of pn diode, respectively. Dose conditions were varied into three conditions of 1${\times}$10$^{11}$ cm$^{-2}$ , 1${\times}$10$^{12}$ cm$^{-2}$ , 1${\times}$10$^{13}$ cm$^{-2}$ at each condition of energies. Characterization of the device was performed by I-V(current-voltage), C-V(capacitance-voltage) and trr(reverse recovery time) measurement. At the optimum condition of irradiation, the reverse recovery time of device has been reduced about 1/5 compared to that of original un-irradiated device.

• Membrane Journal
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• v.26 no.5
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• pp.401-406
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• 2016

In this study, we have investigated the removal of the low level radioactive ions of Cs and I in water by the reverse osmosis (RO) process. The two RO modules produced in domestic region and the waste RO module after the cleaning process were selected. Then we compared removal performance of both Cs and I. The experiments are conducted by varying the concentration of feed, the pressure. As a results, it was confirmed that all three modules are higher I decontamination factor than Cs. And particularly, for the cleaned RO module, its decontamination factor of I was 1140. Since the results at low pressure condition were better than that at high pressure conditions, the use of the direct installation of RO modules on the tap water might be possible. In addition, it was confirmed that the waste RO module after cleaning process using EDTA, SBS and NaOH, increased the decontamination performance better than before cleaning, in particular, the recovery ratio after cleaning was 6.3% higher.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2528-2530
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• 2000

In general, Diode makes a major role in electronic circuit. For example, switching of rectifier, cross current of switching rectifier, energy transfer of electronic element and reverse charge of capacitor, voltage insulation, energy feedback from load to power supply, and such as recovery of storaged energy. Generally, We regard power diode as ideal element, but it has a certain boundary actually, specially, We use diode for detecting circuit peak hold voltage signal. It has cut in voltage. It occurs error of measurement value namely. This error, below in region diode voltage drop (0.7v) measurement value is wholesome signal, Specially, We can not get precision data. Therefore, precision level is low between theoretical and measurement data because of error in actual circuit. Conclusionally, In this paper, We define the error concerning to the power diode characteristics which is used detecting of the minute signal, and recommend the method that minimize measurement error.