• Journal of the Korean Mathematical Society
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• v.13 no.1
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• pp.15-18
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• 1976

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1517-1519
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• 1994

This paper describes electrical environmental study of a 765kV double circuit test line. Corona performance on several candidate conductor bundles has been investigated in the corona cage (single phase simulation facility) since 1984. We have known that six RAIL conductor bundle is the most suitable for the 765kV transmission Line, [3] To investigate electrical environmental impact of the future commerciale line, we build a full sacle 765kV test line in 1993. The test results of Audible Noise, Radio Interference, TV Interference from August, 1993 to Jan. 1994 were measured as $48.7[dBA](L_{50})$. $57.4[dB{\mu}V/m]$(Fair weather, $L_{50})$. $14.5[dB${\mu}$V/m]$(Fair weather, $L_{50}$). We have found that the Audible Noise data were very close to the predicted(48.5 [dBA]) by BPA Corona and Field Effects Computer program, however, the RI and TVI data were much higher than predicted(42 [dBmV/m], $7.9[dB{\mu}V/m)$ by the BPA program. We have investigating the reason of the difference. In the constructing of full scale test line, we developed the tubular tower, 765kV test transformer and hardwares of 765kV transmission line insulator strings. Also we will investigate the effects of plants under the 765kV test Line.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.47-52
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• 2012

The use of a $Ti:LiNbO_3$ symmetric Mach-Zehnder interferometric intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of $46{\times}7{\times}1mm$ and operates at a wavelength of $1.3{\mu}m$. The output characteristic of the interferometer shows the modulation depth of 100% and 75%, and $V_{\pi}$ voltage of 6.6 V, and 6.6 V at the 200 Hz and 1 KHz, respectively. The minimum detectable electric field is ~1.84 V/m, ~3.28 V/m, and ~11.6 V/m, corresponding to a dynamic range of about ~22 dB, ~17 dB, and ~6 dB at frequencies of 500 KHz, 1 MHz and 5 MHz, respectively.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.63-70
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• 2018

Purpose: The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose. Materials and Methods: We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed. Results: Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V5 was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart $V_{30}$ (p = 0.039), $V_{40}$ (p = 0.040), and $V_{50}$ (p = 0.032). Conclusion: Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung $V_{10}$, $V_{20}$, and $V_{30}$ than in 3D-CRT, but could not be proven superior in lung $V_5$. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.

• Radiation Oncology Journal
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• v.36 no.3
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• pp.227-234
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• 2018

Purpose: We compared how doses delivered via two-dimensional (2D) intracavitary brachytherapy (ICBT) and three-dimensional (3D) ICBT varied anatomically. Materials and Methods: A total of 50 patients who received 30 Gy of 3D ICBT after external radiotherapy (RT) were enrolled. We compared the doses of the actual 3D and 2D ICBT plans among patients grouped according to six anatomical variations: differences in a small-bowel V_2Gy, small bowel circumference, the direction of bladder distension, bladder volume, sigmoid V_3.5Gy, and sigmoid circumference. Seven dose parameters were measured in line with the EMBRACE recommendations. Results: In terms of bladder volume, the bladder and small-bowel D_2cc values were lower in the 150-250 mL bladder volume subgroup; and the rectum, sigmoid, and bladder D_2mL values were all lower in the >250 mL subgroup, for 3D vs. 2D ICBT. In the sigmoid V_3.5Gy >2 _mL subgroup, the sigmoid and bladder D_2mL values were significantly lower for 3D than 2D ICBT. The bladder D_2mL value was also significantly lower for 3D ICBT, as reflected by the sigmoid circumference. In patients with a small bowel V_2.0Gy >10 mL or small bowel circumference >15%, most dose parameters were significantly lower for 3D than 2D ICBT. The bladder distension direction did not significantly affect the doses. Conclusion: Compared to 2D ICBT, a greater bladder volume can reduce the internal 3D ICBT organ dose without affecting the target dose.

• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.101-107
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• 2007

This experiment was carried out to develop the substrate mixtures for the production of high quality plug seedlings of cucumber. Peatmoss based substrates, rice hull, carbonized rice hull, decomposed sawdust, perlite and granular rockwool were mixed by five different mixing ratioes (M1, M2, M3, M4 and M5). The cultivars used were cucumber (Cucumis sativus L. cv. Janghyung heukjinju) plants. The higher the content of peatmoss added, the higher the plant growth in terms of plant height, leaf area and total dry weight, which leading to the production of high quality plug seedlings. Seedlings growth of cucumber were greater in M5 mixtures [peatmoss:rice hull:decomposed sawdust=40:40:20(v/v)], M4 mixtures [peatmoss:rice hull:decomposed sawdust:granular rockwool=30:25:20:25(v/v)] and M2 mixtures [peatmoss:rice hull:decomposed sawdust:granular rockwool=20:20:15:25:20(v/v)] The concentrations of nutrient solution (EC) had a great influence on plant height, leaf area, total fresh and dry weight of cucumber seedlings growth. As the concentration of nutrient solution increased from 0.1 to $1.5dS{\cdot}m^{-1}$, the growth and seedling quality of cucumber in plant height, leaf area and dry weight were significantly improved.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1248-1248
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• 2004

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2498-2504
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• 2009

This paper compared the output limit value of the Korean weak electric field strength wireless device in the 8.2MHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 10-20dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 8.2MHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $70.6dB{\mu}V/m$ and $68.3dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $59.8dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 8.2MHz band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2319-2325
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• 2009

This paper compared the output limits value of the Korean weak electric field strength wireless device in the 58kHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 50dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 58kHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $112dB{\mu}V/m$ and $08dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $102.7dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 58kHz band.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.229-232
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• 2001

4H-SIC(silicon carbide) MESFET large signal model was studied using modified Materka-Kacprzak large signal MESFET model. 4H-SiC MESFET device simulation have been conducted by Silvaco's 2D device simulator, ATLAS. The result is modeled using modified Materka large signal model. simulation and modeling results are -8V pinch off voltage, under $V_{GS=0V}$, $V_{DS=25V}$ conditions, $I_{DSS=270㎃}$mm, $G_{m=45㎳}$mm were obtained. Through the power simulation 2GHz, at the bias of $V_{GS=-4V}$ and $V_{DS=25V}$, 10dB Gain, 34dBm(1dB compression point)output power, 7.6W/mm power density, 37% PAE(power added efficiency) were obtained.d.d.d.