• 한국도로학회논문집
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• 제11권1호
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• pp.95-104
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• 2009

본 연구는 아스팔트 콘크리트의 유전율과 공극률의 상관성을 평가하기 위해 수행되었다. 이를 위해 다양한 범위 $(0%{\sim}20%)$의 공극률을 갖는 아스팔트 콘크리트 시편을 제작하였고, 저주파 유전율 측정법인 parallel plate법을 사용하여 아스팔트 콘크리트 시편의 유전율을 측정하였다. 아스팔트 콘크리트 시편의 경우 주파수가 증가함에 따라 유전율은 감소하는 경향을 나타내었고, 사용한 아스팔트 바인더의 종류에 따라 그 감소폭이 다르게 나타났다. 또한 공극률 $0%{\sim}20%$ 사이에서 공극률이 증가함에 따라 유전율 값은 선형적으로 감소하는 경향을 보였다. 더불어 아스팔트 콘크리트 시편의 유전율에 대한 온도 및 함수량 영향을 보정하여 유전율에 따른 공극률의 상관식을 제시하였다. 본 연구를 통해 제시된 아스팔트 콘크리트의 유전율과 공극률의 상관식은 현재 국내외에서 사용하고 있는 유전율을 활용한 비파괴 밀도 측정장비의 보정모델로 활용 가능하며, 향후 국내에서 개발하고자 하는 아스팔트 포장 비파괴 밀도 측정장비의 기본적인 알고리즘으로 활용이 가능할 것이다.

• 비파괴검사학회지
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• 제9권1호
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• pp.56-68
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• 1989

Recently, there are many fields have been required for the precision measurements, as an advanced example of which, a precise change of inner structure during the hydration process of mortar was observed by ultrasonic and dielectric measurements. The results show that it is possible to determine the safety of mortar and mixing ratio, and strength growth and shrinkage rate by heat evolution.

• 한국세라믹학회지
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• 제38권7호
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• pp.667-671
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• 2001

Sawyer-tower 회로를 이용한 강유전 이력곡선의 측정과정에서의 주요 오차 원인을 살펴보고 이에 대한 대안을 제시해 보았다. 강유전체 시편에 존재하는 직류 누설성분에 의해 잔류분극과 항전계는 과대평가될 수 있는 위험성이 항상 있음을 알 수 있었으며 이러한 오차의 보정에 대하여 논의하였다. 또한 강유전 이력곡선의 측정에서 측정하는 시간이 증가되면서 시편의 발열로 인해서 시편의 온도가 증가하게 되어 잔류분극 값과 항전계 값이 감소하는 경향으로 나타남을 관찰하였고, 그 대책을 제안하였다.

• 대한전자공학회논문지
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• 제26권12호
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• pp.1934-1939
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• 1989

The circular microstrip resonator which can be exactly performed with theoretical resonant frequency using the conception of dynamic effective relative dielectric constants is analyzed in this paper. The formula of exact resonant frequency of resonator, in this study, is estabilished by effective resonator dimension and dynamic relative dielectric constant. The measurement of transmission type circular resonator which fabricated by AL2O3 and Epsilam-10 is to prove that the experimental results are more agreed a well with the simulated values by this new method than the simple resonator model.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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• pp.69-73
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• 2002

In ceramic systems, many components including embedded passives and TRL(transmission line) are used for composition of 3-dimensional circuit. So the exact analysis on this components, As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of stripline structure have a large effect on the charactersistics of transmission lines. In this research, of effect of material and geometrical factors on the characteristics of stripline structure is analyzed and quantified by simulation and measurement.

• Journal of Electrical Engineering and information Science
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• 제2권5호
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• pp.40-44
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• 1997

This paper presents the results of studies made for measuring the relative complex permittivity of PCB sheet material in he frequency a range of 100MHz∼1GHz using vector network analyzer. A measurement cell was developed for this purpose using broad-band impedance method and the dielectric constant and loss tangent of two PCBV sheet materials, glass-epoxy and teflon, were measured. The effect of copper cladding was studied.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.779-784
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• 1998

The velocity and amplitude of microwaves are affected by the electromagnetic properties of a material through which the wave propagates. And the electromagnetic properties of a dielectric material such as concrete is represented by its permittivity. For the development of an accurate and reliable nondestructive testing (NDT) technique for concrete structures using microwave, it is necessary to have knowledge about the permittivity of concrete. In this paper, mortar specimens are used to serve as a basis for further measurement of concrete. The effect of water on the permittivity was studied using specimens with different water content. To assure the reliability of the measurement results, a statistical method was introduced.

• Tribology and Lubricants
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• 제27권3호
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• pp.156-161
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• 2011

The rectangular waveguide technique can be used to measure the complex permittivity of dielectric material of various thickness and cross section. This paper presents the analysis system of engine oil permittivity at which deterioration of engine oil is measured at the X-band(8-12.5 GHz). The middle of the rectangular waveguide has engine oil case and is connected with VNA(Vector Network Analyzer) for the measurement of the transmission$(S_{21})$ and reflection$(S_11)$ and then the permittivity is extracted. The deterioration of engine oil is proved by the comparison with both the extracted data and reference data. As the additional research, This paper suggest that an accurate permittivity is considered by not only the wave guide length but the air gap between oil case and the waveguide.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.103-106
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• 1997

The electrical properties and the sensing properties of ZnO-TiO$_2$ composites were investigated by using the complex impedance measurement and voltage-current source and measurement unit. In air, the electrical conductivity of TiO$_2$ added ZnO increase with increasing the content of TiO$_2$ and the relative dielectric constants for 3, 5 and 7mol% TiO$_2$ added ZnO are 7, 13 and 120, respectively. In 3000ppm CO gas, the relative dielectric constants for 3, 5mol% TiO$_2$ added ZnO are 25, 28, respectively.

• 한국초전도ㆍ저온공학회논문지
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• 제4권2호
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• pp.11-15
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• 2002

High speed probe for measurement of sin91e flux quantum circuits is comprised of coaxial cables and microstrip lines in order to carry high speed signals without loss. For the impedance matching between coaxial cable and microstrip line, we have determined the dimension of the microstrip line with 50${\Omega}$ impedance by simulation and then have investigated the effect of line width and cross-sectional shape of signal line, dielectric material, thickness of soldering lead at the coaxial-to-microstrip transition Point, and the an91c between dielectric material and end part of the signal line on the characteristics of signal transmission of the microstrip line. From the simulation, we have found that these all parameter's had influenced on the characteristic of signal transmission on the microstrip line and should be reflected in fabricating high speed probe, We have also determined the dimension of coplanar waveguide to fabricate testing sample for performance test of high speed probe.