Ground Level Enhancements (GLEs) in cosmic ray intensity observed during the period of 1997-2012 have been studied with energetic solar features and disturbances in solar wind plasma parameters and it is seen that all the GLEs have been found to be associated with coronal mass ejections, hard X-ray solar ares and solar radio bursts. All the GLEs have also been found to be associated with sudden jumps in solar proton ux of energy of ≥ 60 Mev. A positive correlation with correlation coefficient of 0.48 has been found between the maximum percentage intensity (Imax%) of Ground Level Enhancements and the peak value of solar proton ux of energy (≥ 60Mev). All the Ground Level Enhancements have been found to be associated with jumps in solar wind plasma velocity (JSWV) events. A positive correlation with correlation coefficient of 0.43 has been found between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the peak value of solar wind plasma velocity of associated (JSWV) events. All the Ground Level Enhancements have been found to be associated with jumps in solar wind plasma pressure (JSWP) events. A positive correlation with correlation coefficient of 0.67 has been found between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the peak value of solar wind plasma pressure of associated (JSWP) events and of 0.68 between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the magnitude of the jump in solar wind plasma pressure of associated (JSWP) events.

This paper briefly introduces the design seismic loads in Korea (KBC 2009). Then, over 10,000 recorded earthquake ground accelerograms, with their magnitude ranging from 4.0 to 8.0 and their epicentral distance ranging from 0 to 200 km, were used to examine the appropriateness of seismic load defined in Korea known as a low-to-moderate seismicity region. The following conclusions are drawn based on the results: (1) The effective peak ground accelerations (EPA) of recorded earthquake accelerograms under M ≤ 6.0 and R ≥15 km appear to be less than that of MCE in Korea for all site conditions defined in KBC 2009. (2) The design spectrum (two-thirds of the intensity of MCE) in KBC 2009 is comparable to those of earthquake records in the magnitude 6 - 7 and the epicentral distance less than 50 km. Therefore, (3) the intensity of Korean design earthquake is considered to be overly high since the Korea peninsula is generally conceived to be a low-seismicity region.

PURPOSES: This study is to evaluate a ground water level effect on frost heaving in road pavements. METHODS: The effects of water table on frost heaving in pavement systems were evaluated from the mechanical analysis using FROST program. The input parameters and boundary conditions were determined by considering climates, pavement sections, and material properties specially subgrade soil types in Korea. RESULTS: When the water table located above the freezing depth, amount of frost heaving caused by freezing the water in pavement itself was big enough to damage in pavement system, although pavement system consists of fully non-frost-susceptible materials with sufficient thickness of anti-freezing layer. The amount of frost heaving was decreased rapidly with increasing the distance between the water table and freezing depth. CONCLUSIONS: It was concluded that there is no engineering problems related with frost heaving in practical sense when the distance between freezing depth and water table is over 1.5m for having subgrade soils less than 50% of #200 sieve passing to meet specification on quality control in Korea.

The purpose of this research is to analyse the changes of ground level of Sungnyemun, the South Gate of Seoul City, and the principles of arch scale through the investigation based on the old records in Joseon dynasty. The result of this research is as follows: 1) The ground level of Sungnyemun, refers the level of foundation stone which was confirmed as original which is verified through the excavation conducted in 2005, maintained 1m's elevated level in 15～16 century and its elevated date presumed in King Sejong's reign(1418～1450). 2) The ground level of Sungnyemun is closely related with the royal funeral ceremony. 3) The width and height scale of Sungnyemun arch is about the ratio of 1 to 1. 4) During the Joseeon dynasty, Sungnyemun was referred as standard of other city wall gate. And it has similar architectural characteristics with Heunginjimun (or East Gate) of Seoul and Hwaseong Janganmun.

본 연구에서는 중저준위 방사성 폐기물 처분장의 지진위험도 평가를 위한 평가용 입력지반운동을 도출하였다. 방사성 폐기물 처분장 부지를 대상으로 한 지진재해도 평가를 수행하여 재해도 곡선을 도출하였으며 도출된 재해도 곡선을 바탕으로 등재해도 스펙트럼을 산정하였다. 등재해도 스펙트럼에 부합하는 30개의 인공지진파를 생성하여 해당 부지의 지반을 대상으로 한 부지응답해석을 수행하였다. 대상부지에 대한 부지응답해석을 통하여 지표면과 처분동굴의 상단과 하단부에서의 입력지진운동을 구하였고 각각의 평균값을 구하여 방사성 폐기물 처분장의 리스크 평가를 위한 평가용 응답스펙트럼을 제시하였다.

본 연구는 산의 남쪽 면에 동서 방향으로 길게 건축한 두 동의 개방돈사 간의 이격거리와 높이차가 환기에 어떤 영향을 미치는지를 시뮬레이션 기법을 이용하여 비교분석하고자 수행되었다. 개방돈사 간의 이격거리는 6과 12 m로, 개방돈사 간의 높이차는 0과 2 m로, 그리고 평균풍속은 여름 1.3과 겨울 1.1 m/s로 각각 설정하였다. 여름철 조건 하에서, 남쪽에 있는 첫 번째 개방돈사 내부의 풍속은 이격거리 및 높이차와는 상관없이 0.75 m/s로 각각 나타났으나 북쪽에 있는 두 번째 개방돈사의 풍속은 높이차가 없을 때 첫 번째 개방돈사의 풍속과 같은 0.75 m/s였고 높이차가 2 m일 때 0.0 m/s에 매우 가깝게 나타났다. 겨울철 조건 하에서, 남쪽에 있는 첫 번째 개방돈사 내부의 풍속은 높이차와는 상관없이 0.15 m/s로 각각 나타났으나 북쪽에 있는 두 번째 개방돈사의 풍속은 이격거리가 12 m일 때 첫 번째 개방돈사의 풍속과 같은 0.15 m/s였고 이격거리가 6 m일 때 0.0 m/s에 매우 가깝게 나타났다. 따라서 개방돈사 간의 이격거리를 12 m 정도로 하고 계단형태보다는 평지형태로 정지작업을 하여 개방돈사를 건축하는 것이 바람직한 것으로 판단되었다.

본 연구는 2001년 8월부터 2003년 12월까지 충남대학교 생명과학대학 내 초지시험포장에서 N 시비수준이 Kentucky bluegrss 잔디초지의 건물수량과 품질에 미치는 영향을 구명하고자 수행하였다. N 시비수준은 100, 150 및 200kg/ha의 3처리를 두어 시험하였으며, 얻어진 결과는 다음과 같다. 2년 평균 ha당 건물수량은 N 시비수준이 높아짐에 따라 현저히 증가되어, N 100, 150 및 200kg시비수준에서 각각 6,317, 8

The loss of safety for reservoirs brought about by climate change and facility aging leads to reservoir failures, which results in the loss of lives and property damage in downstream areas. Therefore, it is necessary to provide a Reservoir(Dam) Failure Forecasting System for downstream residents to detect the early signs of failure (with sensors) in real-time and perform safety management to prevent and minimize possible damage. Ground water level meter was installed for changes of seepage and understanding of underground stability, and its management criteria was established in change of ground water level up to dam height. Analysis results show that distribution of values are scattered so it is necessary to do monitering for 1 year to set up for numerical fitting.

국내 하천에서 사주 상 식생 활착 현상이 급속하게 진행되고 있다. 1960년대 산업화와 도시화 이전 우리나라 하천은 모래, 자갈이대부분인이른바 'White River (백사장하천)'이었으나, 1970년대이후댐건설, 하천정비등으로유황과유사이 송특성이 교란되어수변에 식생이번무하게 되는이른바 'Green River (식생하천)'가진행중이다. 본 연구는비조절하천사주 상 식생활착에 영향을 미치는 인자 중에서 수위, 수온, 강우, 토양수분, 토양입경 등의 상호연관

In order to investigate horizontal wind field in the boundary layer around Pusan area, wind speed and wind direction measured at 14 AWS(Automatic Weather Station), 1997, was used. The wind direction at PRMO(Pusan Regional Meterological Office) was showed that southwest and northeast wind dominated for spring and summer, northeast wind for fall and northwest for winter. Anticline flow was showed at 'Gaekumm' which is located between Mt. Backyang(641 m) and Mt. Yumkwang(503 m) and affected on wind field at 'Pusanjin'. The low wind speed and various wind direction was represented at the basin topography, 'Buckgu', 'Jeasong', 'Ilkwang' and 'Kijang'. The annual mean wind speed at 14 sites, 2.5 ms-1, was lower than that measured at PRMO, 3.9 ms-1. The wind direction analysis showed that the case of same direction in compare with that measured at PRMO is about 54% and case of opposite direction is about 12%. Annual and seasonal mean windrose showed wind direction is affected by not only synoptic weather state but also topography.