• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.12 s.354
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• pp.83-88
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• 2006

In this paper, we propose a new cross bar embedded structure for improvement of attenuation characteristics along the different lossy media. A general characterization procedure based on the extraction of the characteristic impedance and propagation constant for analyzing a single MIS(Metal-Insulator-Semiconductor) transmission line used and an analysis for a new substrate shielding MIS structure consisting of grounded crossbars at the interface between Si and Sio2 layer using the Finite-Difference Time-Domain(FDTD) technique is used. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded cross bar lines over time-domain signal has been examined. The extracted, distributed frequency-dependent transmission line parameters as well as the line voltages and currents, and also corresponding equivalent circuit parameters have been examined as function of frequency. It is shown that the quality factor of the transmission line can be improved without significant changes in the characteristic impedance and effective dielectric constant.

• KOREAN POULTRY JOURNAL
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• v.44 no.6
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• pp.140-142
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• 2012

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.8
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• pp.61-67
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• 2010

A characterization procedure for analyzing symmetric coupled MIS(Metal-Insulator-Semiconductor) transmission line is used the same procedure as a general single layer symmetric coupled line with perfect dielectric substrate from the extraction of the characteristic impedance and propagation constant for even- and odd-mode. In this paper, an analysis for a new substrate shielding symmetric coupled MIS structure consisting of grounded crossbar at the interface between Si and SiO2 layer using the Finite-Difference Time-Domain (FDTD) method is presented. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded crossbar lines over time-domain signal has been examined. Symmetric coupled MIS transmission line parameters for even- and odd-mode are investigated as the functions of frequency, and the extracted distributed frequency-dependent transmission line parameters and corresponding equivalent circuit parameters as well as quality factor for the new MIS crossbar embedded structure are also presented. It is shown that the quality factor of the symmetric coupled transmission line can be improved without significant change in the characteristic impedance and effective dielectric constant.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.12
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• pp.35-41
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• 2011

In this paper, an analysis for a new substrate shielding symmetric coupled MIS structure consisting of grounded crossbar at the interface between Si and SiO2 layer using the Finite-Difference Time-Domain(FDTD) method is presented. In order to reduce the substrate effects on the transmission line characteristics, a shielding structure consisting of grounded crossbar lines over time-domain signal has been examined. Parameters of symmetric coupled MIS transmission line with various gaps between crossbars for even- and odd-mode are investigated as the functions of frequency, and the extracted distributed frequency-dependent transmission line parameters and corresponding equivalent circuit parameters as well as quality factor for the new MIS crossbar embedded structure are also presented. It is shown that the quality factor of the symmetric coupled transmission line can be improved without significant change in the characteristic impedance and effective dielectric constant.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1558-1563
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• 2013

In this paper, we analyze the radio propagation path loss characteristics for the vertical electric dipole radiation over the perfect electric conductor(PEC) ground plane. Most research have been performed about the electromagnetic analysis of vertical electric dipole in free space for time domain or frequency domain. But this paper present the radio propagation path loss over PEC ground plane in time domain under the assumption of the vertical electric dipole as a base station. From the simulated results, the ground plane effect can change the location of near field from transmitting antenna and the transient responses at mobile are calculated. The results of this paper can be applied to surface radar or signal processing applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1108-1115
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• 2004

A new type of a Rotman lens is presented in this paper fur millimeter-wave applications, such as collision avoidance radar. A dielectric slab Rotman lens is proposed to reduce the conductor loss and to create an appropriate farm for favorable implementation at millimeter-wave frequency. The proposed lens consists of a dielectric slab and slot lines whereas the conventional lenses are constructed with parallel conducting plates. The dielectric slab Rotman lens excited in TE$\_$0/ mode shows a high degree of confinement for the fields, low dispersion, and has an appropriate feed structure. A prototype lens has been designed and fabricated with 9 beam ports and 9 array ports together with 9 tapered slot antennas. This lens has been tested in the range from 10 GHz to 15 GHz and the measured beam widths are about 15$^{\circ}$ at 13 GHz. The measurements also show low mutual coupling between beam ports and an efficiency of about 34.6 %. The overall performance is comparable to that of conventional Rotman lenses even though the prototype was tested at lower than desired frequencies in the microwave frequency range due to our limited resources for fabrications and measurements. It is expected that at millimeter-wave frequency the dielectric slab Rotman lens will have lower conductor loss and lower mutual coupling than conventional Rotman lenses.an lenses.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.505-506
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• 2011

직류송전은 낮은 장거리 송전 손실, 다른 주파수간 연계에 적합하여 많은 관심을 받고 있는 송전방식이다. 그러나 상용화된 기간이 짧아 관련된 기술수준이나 규격들이 아직 보완할 사항이 많이 있다. 특히, 교류선로와 달리 극성에 따른 코로나 발생 메커니즘이 달라 송전도체의 부식에 대한 연구가 필요한 실정이다. 본 논문에서는 500kV HVDC 시험선로에서 약 30개월간 운전되었던 송전도체를 이용하여 극성에 따른 도체의 부식정도를 비교하였으며, 보다 정확한 비교정도 및 부식원을 파악하기 위하여 SEM을 통해 부식된 부분의 성분비를 분석하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.139-146
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• 2008

Conductors in overhead transmission lines are exposed under various environmental conditions for a long period of time, so that they may be slowly degraded due to air pollutant or thermal history. Aged conductors may reduce power system reliability and public safety. Therefore, diagnosis of aged conductors in service becomes more important concerns with respect to keeping power delivery stable with a proper capability, replacing aged conductors, or constructing a new line. In this paper, we posed a new method to diagnose the refurbishment life and estimate the remaining life of aged conductors by measuring dips. As analyzing some relations of conductor temperature, conductor current, and tension load, it could be verified that dip exactly shows mechanical tension loss for aged conductor. Based on several simulation results, it was shown that the proposed method may be effectively used to diagnose the refurbishment life or remaining one of overhead conductors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.649-656
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• 2000

In this paper, a closed exact from and its approximation of the characteristic impedance of a lossy coaxial line with a thick outer conductor are proposed. It is also shown for 3.5mm reference air line that the proposed approximation is accurate over the entire operating frequency range of the line.

• KAPE Magazine
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• no.52
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• pp.16-17
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• 2000

등급판정결과에 따라 소도체에 찍히는 도장은 `등급판정인`과 `결함인` 두가지가 있다. 등급판정인은 소도체의 육량등급과 육질등급을 구분하여 판정한 결과를 A1$^+$부터 D등급까지 날인하고 있으며, 결함인은 도체에 결함이 발견 되었을 경우 그 종류에 따라 도체에 표시를 다르게 하며 ㅎ, ㅈ, ㅇ, ㅁ, ㄴ, ㅅ, ㄱ, ㅌ 등 6종류가 있다. 소도체의 경락가격은 1차적으로 육량등급과 육질등급에 의해 달라지지만 결함의 표시유무에 의해서도 크게 달라진다. 이에 결함의 종류에 따라 발생되는 손실과 출현율 등을 2000년 1월부터 10월까지 농협서울공판장에서 등급판정된 한우 51,444두를 대상으로 살펴보기로 하겠다.