• Journal of the Korean association of regional geographers
• /
• v.22 no.4
• /
• pp.875-886
• /
• 2016

The eastern coast of Seopo-myeon, Sancheon-si in the South Coast is a bay almost completely separated from open sea by Changseon and Namhae Islands. Marine terraces in this area can be classified into geomorphic surfaces with elevations of 10~12m, 15~18m, 20~24m, 25~28m, 30~33m, 35~38m, 40~45m, 45~50m and 54m. This marine terrace system is similar to the Boryeong area in the West Coast. The geomorphic surfaces distribute along ridges and show relatively small areas. The young and old surfaces show a mixed distributional pattern. This distributional pattern contrasts to the East Coast where the oldest surface farthest from the coastline is parallel to the coast and age of the surfaces increases with a distance from the coast. These seem to result in high energy waves by typhoon that developed wave-cut platform on hill areas with relatively complex relief in a short time.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.12A
• /
• pp.1883-1890
• /
• 1999

Wireless communication in an urban area, the accurate prediction of wave propagation characteristics are very important to determine communication service areas, select optimal base-stations, and design cells, etc. The CCIR model is a propagation prediction model using a shadowing by the buildings in an urban area. This model represent the shadowing rate by the means of the effect of shadowing between base-station and mobile unit in a shaped linear plane. But, This one occurred a lot of prediction error because it did not consider that density area by the buildings and terrain configurations by the hill and mountain on Line-Of-Sight. In this thesis, an improved propagation prediction model is proposed to reduce prediction error. We presents a new equation, which is using the SAS. This equation is associated with the shadow height by the buildings that considers the topology and the number of blocks that can affect the building shadow in the Line-Of-Sight. We measure the received electrical field level of base-station that high density area, medium density area, and low density area, and then compare and analysis the result to prediction of CCIR model and proposed model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model.

• 한국노년학
• /
• v.37 no.1
• /
• pp.1-14
• /
• 2017

The purpose of this study was to examine the effect of vision and hearing limitation on the onset of disability among Korean elderly with the consideration of social participation and depression. Study population consisted of 2,670 people aged 65 and above who participated in both the 1st(2006) and 2nd(2008) wave of the Korean Longitudinal Study of Aging(KLoSA), and also reported no ADL or IADL disability in 2006. As the results, first, it found that vision and hearing limitation, social participation, and depression were significant risk factors for the onset of IADL disability in unadjusted analysis. After multivariable adjustment, however, only vision limitation showed significant association with the onset of IADL disability. Second, in the logistic analysis with four categorized variables(vision/hearing limitation + social participation, vision/hearing limitation + depression), the elderly who had vision or hearing limitation had a significantly 1.7 times higher odds ratio for disability onset if they also had low social participation compared with those who had no vision or hearing limitation, and high social participation. Whereas, depression was not significantly associated with the relationship between vision or hearing limitation, and disability onset. The study suggests that the intervention program developed to prevent social isolation of older people with vision or hearing limitation, may be helpful to reduce and postpone the risk of disability onset as well as early detection and treatment of vision or hearing problems.

• Journal of Korean Society of Forest Science
• /
• v.112 no.3
• /
• pp.340-351
• /
• 2023

Landslides are major natural geological hazards that cause enormous property damage and human casualties annually. The vulnerability of mountainous areas to landslides is further exacerbated by the impacts of climate change. Soil depth is a crucial parameter in landslide and debris flow analysis, and plays an important role in the evaluation of watershed hydrological processes that affect slope stability. An accurate method of estimating soil depth is to directly investigate the soil strata in the field. However, this requires significant amounts of time and money; thus, numerous models for predicting soil depth have been proposed. However, they still have limitations in terms of practicality and accuracy. In this study, 71 seismic survey results were collected from domestic mountainous areas to estimate soil depth on hill slopes. Soil depth was estimated on the basis of a shear wave velocity of 700 m/s, and a database was established for slope angle, elevation, and soil depth. Consequently, the statistical characteristics of soil depth were analyzed, and the correlations between slope angle and soil depth, and between elevation and soil depth were investigated. Moreover, various soil depth prediction models based on slope angle were investigated, and corrected linear and exponential soil depth prediction models were proposed.