• 한국전기전자재료학회논문지
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• 제27권3호
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• pp.195-198
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• 2014

In this paper, a measurement method to obtain the optical properties of a liquid base on a side-polished single mode fiber was proposed and demonstrated. The device showed periodic resonance coupling against wavelengths. The refractive index and dispersion characteristics of a liquid were calculated by use of the spacings of periodic resonance wavelengths of the device. The thermo-optic coefficient of the liquid was obtained by monitering the shift of resonance wavelengths of the devices with change of environmental temperature.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1235-1241
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• 2012

Aluminium (Al)-doped zinc oxide (AZO) thin films with different Al concentrations were prepared by the solgel spin-coating method. Optical parameters such as the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity were studied in order to investigate the effects of the Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the AZO thin films were found to be affected by Al incorporation. The optical conductivity of the AZO thin films also increases with increasing photon energy.

• Structural Monitoring and Maintenance
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• 제9권4호
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• pp.373-388
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• 2022

A USW based diagnostic procedure is presented for estimating the depth of surface-breaking cracks. The diagnosis is demonstrated on seven lab-scale SFRC beam specimens, which are subjected to the CMOD controlled three-point bending test to create real bending cracks. Then, the recorded multiple ultrasonic signals are examined with the signal processing techniques, including wavelet transform and two-dimensional Fourier transform, to investigate the relationships between the crack depth and two diagnostic indices, namely the attenuation coefficient and dispersion index (DI). Finally, the reliabilities of these indices for depth estimation are verified with the visually measured crack depths as well as the crack features obtained with a digital image processing algorithm. It is found that the DI outperforms the attenuation coefficient in depth estimation, where this index displays good agreement with the visual inspection for 86% of the inspected specimens.

• Earthquakes and Structures
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• 제10권2호
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• pp.329-350
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• 2016

A parametric study was conducted to investigate the seismic deformation demands in terms of drift ratio, plastic base rotation and compression strain on rectangular wall members in frame-wall systems. The wall index defined as ratio of total wall area to the floor plan area was kept as variable in frame-wall models and its relation with the seismic demand at the base of the wall was investigated. The wall indexes of analyzed models are in the range of 0.2-2%. 4, 8 and 12-story frame-wall models were created. The seismic behavior of frame-wall models were calculated using nonlinear time-history analysis and design spectrum matched ground motion set. Analyses results revealed that the increased wall index led to significant reduction in the top and inter-story displacement demands especially for 4-story models. The calculated average inter-story drift decreased from 1.5% to 0.5% for 4-story models. The average drift ratio in 8- and 12-story models has changed from approximately 1.5% to 0.75%. As the wall index increases, the dispersion in the calculated drifts due to ground motion variability decreased considerably. This is mainly due to increase in the lateral stiffness of models that leads their fundamental period of vibration to fall into zone of the response spectra that has smaller dispersion for scaled ground motion data set. When walls were assessed according to plastic rotation limits defined in ASCE/SEI 41, it was seen that the walls in frame-wall systems with low wall index in the range of 0.2-0.6% could seldom survive the design earthquake without major damage. Concrete compressive strains calculated in all frame-wall structures were much higher than the limit allowed for design, ${\varepsilon}_c$=0.0035, so confinement is required at the boundaries. For rectangular walls above the wall index value of 1.0% nearly all walls assure at least life safety (LS) performance criteria. It is proposed that in the design of dual systems where frames and walls are connected by link and transverse beams, the minimum value of wall index should be greater than 0.6%, in order to prevent excessive damage to wall members.

• 펄프종이기술
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• 제35권2호
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• pp.18-25
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• 2003

The adsorption of co-cationic dual polymer system was investigated as was the fiber dispersion stability of a paper stock suspension. Polyaluminum chloride(PAC) and polyamidoamine epichlorohy-drin(PAE) polymers were used as wet-end additives. The adsorbed amounts of PAE polymer in a wet stock were measured by using polyelectrolytic PCD titration. The sheet forming experiments were carried out in a standard handsheet machine. Fiber dispersion stability and relative retention were evaluated in terms of M/K non-uniformity index and sheet basis weight, respectively. The PAE polymer adsorption of Langmuir-isothermal type decreased with increasing PAC addition level. The combination of the two cationic polymers presumably exerts a site-blocking effect by the low molecular weight PAC which gives a partial charge neutralization at a minimum level of addition. From a thermodynamic view point of PAE adsorption, an increase in adsorption entropy and a decrease in train number suggests that the PAR polymer has an extended conformation structure that potentially leads to an enhancement of the fiber dispersion stability. This conclusion is supported by handsheet experiments that examined the PAC-PAE dual polymer effects on the sheet formation and retention.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.205-206
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• 2006

• 에너지공학
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• 제24권4호
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• pp.117-123
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• 2015

최근 산업체에서는 성분을 알 수 없거나, 데이터베이스를 보유하지 않는 가스들의 사용이 증가하고 있는 추세이다. 가스들의 사용양이 증가함에 따라 확산범위와 속도를 예측 할 수 있는 소프트웨어들이 사용의 중요성이 증가하고 있는데, 이들 소프트웨어들은 기존에 보유하고 있는 가스들의 자료에 의존하여 확산거리 및 속도를 예측하기 때문에 새로운 가스들이 확산거리(속도)를 예측하기는 매우 어려운 실정이다. 따라서 본 연구에서는 가스의 확산 및 폭발을 예측할 수 있는 FLACS S/W 및 등가가스를 이용하여 불특정한 가스들의 확산을 예측할 수 있는 방법을 제시하고자 한다.

• 응용통계연구
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• 제17권1호
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• pp.13-26
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• 2004

경제성장이론에 의하면 특정 산업에 종사하는 사업체들의 입지 행태는 업종별로 서로 공간적 관련성을 갖는다. 본 연구에서는 음이항분포의 산포모수의 특성을 이용하여 산업 활동의 공간집적도를 계량화하기 위한 산업집중지수를 정의하고 이를 이용하여 특정업종에 종사하는 사업체들의 입지행태에 있어서 공간적 변화경향을 통계적으로 규명하고자 하였다. 1995년도와 2000년도의 사업체 기초통계조사 자료를 이용하여 충북지역의 지식기반산업 7개 업종과 주력기간산업 9개 업종에 대해 산업집중지수를 추정하여 이를 기반으로 업종별 사업체들의 공간적 입지행태 변화경향을 분석하였고 지역산업 활성화에 필요한 업종의 선택 및 집중화문제해결에 산업집중지수가 활용될 수 있음을 보였다.

• 통상정보연구
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• 제18권1호
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• pp.235-258
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• 2016

본 연구는 산업연관표를 중심으로 2011년~2013년 기간의 실측표기준의 투입산출물표(Input-output Table)를 사용하여 동 기간의 국내 해외직접투자(FDI) 유입액을 한국표준산업분류(KSIC 30부문)기준으로 재분류 및 통합하여 적용한 결과 3개년 평균 국내 외국인직접투자 유입액은 15조 3,000억원이고, 평균총생산유발액은 45조 8,000억원으로 추계되었다. 국내 외국인직접투자 유입의 특징은 감응도계수 및 영향력계수가 큰 산업인 화학제품, 전기 및 전자기기, 금속제품에 편중되어 있다. 특히 중간재로 활용되는 감응도계수가 큰 산업에 국내 외국인직접투자 유치가 이루어지면 국내 경제적 산업파급효과가 큰 것으로 나타난다.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.538-542
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• 2013

We propose a simple model to elucidate the dispersion behavior of spiraling modes on silver nanowire by finding correspondence parameters and building a simple equivalent relationship with the planar insulator-metal-insulator geometry. The characteristics approximated for the proposed structure are compared with the results from an exact solution obtained by solving Maxwell's equation in cylindrical coordinates. The effective refractive index for our proposed equivalent model is in good agreement with that for the exact solution in the 400-2000 nm wavelength range. In particular, when the radius of the silver nanowire is 100 nm, the calculated index shows typical improvements; the average percentage error for the real part of the effective refractive index is reduced to only 5% for the $0^{th}$ order mode (11.9% in previous results) and 1.5% for the $1^{st}$ order mode (24.8% in previous results) in the 400-800 nm wavelength range. This equivalent model approach is expected to provide further insight into understanding the important behavior of nanowire waveguides.