• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.193-196
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• 2000

A new type low-pass filter design method based on a coupled line and transmission line theory is proposed to suppress harmonics by attenuation poles in the stop band. The design formula are derived using the equivalent circuit of a coupled transmission line. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range and low insertion loss. The seventh-order low-pass filter designed by present method has a cutoff frequency of 0.9 CHz with a 0.01 dB ripple level. The coupled line type low-pass filter with strip line configuration was fabricated by using a high-temperature superconducting (HTS : YBa$_2$Cu$_3$O$_{7-{\delta}}$ thin film on MgO(100) substrate. Since the HTS coupled tine type low-pass filter was proposed with five attenuation poles in stop band such as 1.8, 2.5, 4, 5.5, 6.2 GHz. The fabricated low-pass filter has improved the attenuation characteristics up to seven times of the cutoff frequency.

• 전자공학회논문지A
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• 제33A권5호
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• pp.65-74
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• 1996

in this paper, the propagation characteristics of the dominant modes in multiple coupled microstrip lines on a magnetized ferrite substrate are analyzed. The propagation constants and characteristic impedances are calculated by using the spectral domain method. With the numerical results, multi-port impedance parameters as well as scattering parameters are derived from nonreciprocal transmission line equations which are consistent with conventional transmission line theory. In additon, the numerical resutls of nonreciprocal characteristics for various values of structural, material parameters, and external magnetic fields are also presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.116-118
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• 1999

A fault location algorithm that is suitable for parallel transmission line which contains a teed circuit is presented. The method uses only the local end voltage and current signals. Zero sequence currents of other lines are calculated by distribution factors, and distance equations are solved by recursive calculation.

• 센서학회지
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• 제23권5호
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• pp.349-355
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• 2014

In this paper, we developed a new method to transmit multiple visible light channels in time division mode using the AC power line frequency in order to prevent the crosstalk between adjacent optical signals. Synchronizing pulses are generated from the 220 V power line, and one pulse period is subdivided into several time slots for visible light channels. Each channel transmits data in a predefined time slot without interfering adjacent channels. In experiments, synchronizing pulses with a repetition rate of 240 Hz were generated from the 60 Hz power line, and three VLC channels with a bit rate of 9.6 kbps transmitted data independently using the time slots between synchronizing pulses. This configuration is very useful in constructing time division VLC networks for multiple sensors.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1201-1202
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• 2008

In this paper, using symmetrical condensed node(SCN), the TLM numerical technique has been successfully applied to microstrip meander line. A detailed technique of the symmetrical condensed node(SCN) may be used to model planar microstrip transmission line is presented. Also, the S-parameters $S_{11}$ and $S_{21}$ of microstrip meander line have been computed. From obtained results, TLM analysis is shown to be an efficient method for modeling complicated structure of planar microstrip transmission line.

• 전기학회논문지
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• 제57권12호
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• pp.2139-2146
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• 2008

This paper presents a numerical algorithm for fault location estimation which used to data from both end of the transmission line. The proposed algorithm is also based on the synchronized voltage and current phasor measured from the PMUs(Phasor Measurement Units) in the time-domain. This paper has separated from two part of with/without shunt capacitance(short/long distance). Most fault was arc one-ground fault which is 75% over [1]. so most study focused with it. In this paper, the numerical algorithm has calculated to distance for ground fault and line-line fault. In this paper, the algorithm is given with/without shunt capacitance using II parameter line model, simple impedance model and estimated using DFT(Discrete Fourier Transform) and the LES(Least Error Squares Method). To verify the validity of the proposed algorithm, the EMTP(Electro- Magnetic Transient Program) and MATLAB did used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1817-1819
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• 2001

For an efficient calculation of scattering matrix of planar transmission line with step discontinuity. Mode Matching Method combined with Vector Finite Element Method is adopted. Calculating effective widths are replaced with their respective equivalent planar waveguide corresponding to the microstrip width, Propagation Constant is calculated from the Vector finite element. Mode matching method is used for deriving scattering parameters.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.32-41
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• 2011

This paper presents a new method of Fuzzy Particle Swarm Optimization (FPSO)-based Congestion Management (CM) by optimal rescheduling of active powers of generators. In the proposed method, generators are selected based on their sensitivity to the congested line for efficient utilization. The task of optimally rescheduling the active powers of the participating generators to reduce congestion in the transmission line is attempted by FPSO, Fitness Distance Ratio PSO (FDR-PSO), and conventional PSO. The FPSO and FDR-PSO algorithms are tested on the IEEE 30-bus and Practical Indian 75-bus systems, after which the results are compared with conventional PSO to determine the effectiveness of CM. Compared with FDR-PSO and PSO, FPSO can better perform the optimal rescheduling of generators to relieve congestion in the transmission line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1565-1567
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• 1994

This paper describes a methodology for the three dimensional electric field calculation around parallel and orthogonal transmission lines. A nonuniform modeling method of finite line using linear line charges is proposed through the error analysis, Several examples of three dimensional electric field calculation are carried out by this method.

• 대한기계학회논문집B
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• 제28권11호
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• pp.1359-1367
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• 2004

The demand of vacuum pump has been increased in the process of semi-conduct manufacturing, as a core component. The response of the system for vacuum pump performance test can be utilized to assess the system and to obtain the reliability of the apparatus for the test. The system consists of gas supply tank, pressure chamber, measurement chamber and transmission line. Transient analysis for compressible fluid has been conducted to evaluate the dynamic characteristic of the volume terminated transmission line. Numerical approach based on the method of characteristics is used for the analysis. The response is evaluated with the important parameters for the system: i.e., length and diameter of the line, volume of the terminal tank. Using the numerical results, pumping speeds are calculated and then compared to the experimental results.