• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1233-1239
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• 2004

This study analysis the current level of the Korea High Speed Line by mathematical model of the rail and compensation capacitors. The rail and compensation capacitors are represented by transmission parameters and the analysis is processed by computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.2
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• pp.146-151
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• 1986

The analysis procedure for open-circuited interdigital multiple coupled microstrip-line structures for applications as wideband DC blocks are presented. The exact frequency responses for the transmission coefficient computed by utilizing the quasi-TEM parameters of coupled microstrip lines are shown.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.167-175
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• 2013

The wave propagation characteristics of an acoustic metamaterial composed of periodically repeated one-dimensional Helmholtz resonator array was investigated considering the effects of dimensional changes of the resonator geometry on the transmission coefficient and band gap. The effective impedance and transmission coefficient of the acoustic metamaterials are obtained based on the acoustic transmission line method. The designed acoustic metamaterials exhibit band gaps and negative bulk modulus that are non-existent properties in the nature. The band gap of the acoustic metamaterial is strongly dependent on the geometry parameters of Helmholtz resonators and lattice spacing. Also, a new type of metamaterial that is periodically constructed with two different resonators was designed to open the local resonance band gap without change of Bragg scattering.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.189-197
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• 2004

The thermal rating of an overhead conductor, which is the maximum allowable current, is generally calculated on the basis of heat balance equation found in IEEE P738 standard. This is given as a function of the weather conditions such as air temperature, wind speed, wind direction, and sun heat. Wind speed among such weather parameters is strongly affected on determining the line rating when it appears very low level. Therefore there may occur inaccuracy since most anemometers used in line rating monitor systems may show low resolutions and stall speed performance. In this paper, we introduce a new methodology for determining the dynamic line rating in overhead transmission lines, without using my anemometer. It was shown that wind speed can be estimated by the temperatures of 2 indirect conductors, and through experimental study, the dynamic line rating obtained by the estimated wind speed was very closely that of weather model.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.871-874
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• 1998

A new transmission line parameter extraction method of iC interconnects on silicon substrate is presented. To extract the acurate parameters, the silicon substrate effects were taken into account. Since the electromagnetic fields under the silicon substrate are propagated with slow wave mode, effective dielectric constant and different ground plane with the multi-layer dielectric structures were employed for inductance and capacitance matrix determination. Then accurate signal transients simulation were performed with HSPICE by using the parameters. It was shown that the simulation resutls has an excellent agreement with TDR/TDT measurements.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.2
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• pp.182-188
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• 1986

A method of wideband constant phase control is proposed. This can be applied to reflection type phase shifter with p-i-n diode. Using the proposed method, a microwave phase network which consists of a transmission line and reactive circuit element is suggested. By determining theproper values of design parameters, the desired wideband constant phase with different specification can easily be designed. Also, using the proposed method, the parameters variation, and 1.1 dB of insertion loss in the range of 12% bandwidth.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1106-1115
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• 2006

In this paper, the transmission characteristics and equivalent circuit model of microstrip transmission line having defected ground structure (DGS) in multilayer substrates are described fur high frequency region. In order to perform the study, the second dielectric layer is attached additionally onto the bottom(ground) plane of the basic DGS microstrip line consisted of the microstrip line and DGS. The dielectric constant and thickness of the second dielectric layer are adjusted to get various transmission characteristics and model parameters, and to analysis the effect of the second dielectric layer ultimately. According to this paper, the effect and equivalent circuits due to the attached dielectric substrate are verified separately, and this is expected to be applied to high frequency circuit design in the future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1091-1096
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• 2009

Some closed-form expressions for circuit parameters are derived based on the equivalent circuits for the resonant MTM-TL(open and short). The lumped series resistance and shunt conductance, which explain radiation effects of a unit cell may be found by |$S_{11}$|(simulated or measured) with open and short terminations, respectively. The EM-simulated results, circuit-simulated results(obtained using extracted circuit parameters) and measurement results are shown to be in good agreement.

• Wind and Structures
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• v.11 no.3
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• pp.193-208
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• 2008

This paper focuses on assessing the failure of one of the transmission towers that collapsed in Winnipeg, Canada, as a result of a microburst event. The study is conducted using a fluid-structure numerical model that was developed in-house. A major challenge in microburst-related problems is that the forces acting on a structure vary with the microburst parameters including the descending jet velocity, the diameter of the event and the relative location between the structure and the jet. The numerical model, which combines wind field data for microbursts together with a non-linear finite element formulation, is capable of predicting the progressive failure of a tower that initiates after one of its member reaches its capacity. The model is employed first to determine the microburst parameters that are likely to initiate failure of a number of critical members of the tower. Progressive failure analysis of the tower is then conducted by applying the loads associated with those critical configurations. The analysis predicts a collapse of the conductors cross-arm under a microburst reference velocity that is almost equal to the corresponding value for normal wind load that was used in the design of the structure. A similarity between the predicted modes of failure and the post event field observations was shown.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2324-2326
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• 2005

For the analysis of domestic Indoor power line network, we defined parameters of transmission line and simulated it. We conducted the case study which shows the general characteristics of KSC3302 power line. We will develop software for indoor power line network analysis.