• 비파괴검사학회지
• /
• 제31권4호
• /
• pp.343-350
• /
• 2011

최근 전세계적으로 큰 지진이 빈번히 발생하고 있고, 국내에서도 지진 발생 빈도가 높아짐에 따라 노후화된 토목 구조물에 대한 내진 성능 평가 및 구조 건전성 평가의 중요성이 재조명되고 있다. 하지만 국내 기존 댐 수문에 대한 관련 연구는 미비한 실정이다. 본 연구에서는 댐 수문 내진 성능 평가 및 구조 건전성 평가의 기초자료가 펴는 댐 수문의 통특성 추정을 위하여 댐 수문에 적용할 수 있는 실험기법을 정립하고, 정립된 실험기법을 통하여 두 종류의 댐 수문에 대한 현장 실험을 수행하였다. 동특성 추정에는 모드 해석 방법 중에 하나인 주파수영역분해기법을 이용하였다. 상시진동실험과 강제진동실험을 이용하여 댐 수문의 동특성을 추정함으로써 두 방법의 성능을 비교하였으며, 상시진동실험이 댐 수문의 동특성을 추정하는데 매우 효과적인 방법임을 확인하였다.

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 2003년도 춘계학술대회 논문집
• /
• pp.423-423
• /
• 2003

The radiative properties of atmospheric aerosol are determined by the mass and chemical characteristics, and optical properties such as aerosol optical depth (AOD), ngstr m parameter ( $\alpha$) and single scattering albedo (SSA). In particular these aerosol optical properties also determine surface temperature perturbation that may give some information in understanding the regional atmospheric radiative forcing. For understanding the radiative forcing and regional surce of aerosol, this paper summarizes and compares the aerosol optical properties results from and compares the atmospheric aerosol optical properties results from two different experiments: Anmyeon 2000 and Jeju 2001. Korea Global Atmosphere Watch Observatory (KGAWO) at Anmyeon island and ACE-Asia super-site at Gosan Jeju island have measured the radiations and aerosols since the year of 2000. The sites are located in the mid-west and south of Korea peninsula where it is strongly affected by the Asian dust coming from China region in every spring. Aerosol optical properties over both sites were measured through the ground-based sun and sky radiometers were analyzed for understanding the radiation and climate properties. Number concentration and chemical components of aerosol were additionally analyzed for the source estimation in the transportation. The frequency distributions of aerosol optical depth are rather narrow with a modal vaiue of 0.38 at both sites. However, the distributions of show one peak (1.13) at Jeju but two peaks (0.63 and 1.13) at Anmyeon. In the cases of Anmyeon, one peak around 0.63 corresponds to relatively dust-free cases, and the second peak around 1.13 characterizes the situation when Asian dust is presented. The correlation between AOD and resulted high correlation on the wide range with high values of optical depth at Anmyeon, otherwise a narrow range of with moderate to low AOD at Jeju. In dust free condition SSA decrease with waveleneth while in the presence of Asian dust SSA either stays neutral or increases slightly with wavelength. The change of surface temperature shows the stronger positive correlations with aerosol optical depth increase at Anmyeon than Jeju. In the chemical properties the aerosol are related to high concentrations in inorganic matters, SO$^4$, NO$_3$, CA2+ in fine and coarse.