• Title/Summary/Keyword: 진동 지표

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Seismic Safety Evaluation of Korean R/C School Buildings Built in the 1980s (1980년대 국내 철근콘크리트 학교건물의 내진 안전성 평가에 관한 연구)

  • Lee, Kang-Seok;Wi, Jeong-Du;Kim, Yong-In;Lee, Hyun-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.5 s.57
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    • pp.149-159
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    • 2009
  • The main purpose of this study is to evaluate the seismic safety of Korean R/C school buildings built in the 1980s, based on "the Japanese Standard for Evaluation of Seismic Capacity of Existing R/C Buildings", the nonlinear static and the nonlinear dynamic analyses. The evaluation result of the Japanese Standard showed that R/C school buildings built in the 1980s have 0.2 through 0.4 of seismic indices($I_S$). This result indicates that more than medium damage could be potentially occurred under a medium intensity level of ground motion(150g). The results of the nonlinear analyses and the post-earthquake damage evaluation method showed that Korean R/C school buildings can be suffered moderate and severe damages under a 150gal and a 200gal intensity levels of ground motions, respectively. These results reveal that R/C school buildings should be urgently required a actual earthquake preparedness measures including seismic strengthening for future earthquake.

Long-Term Variations of Water Quality in Jinhae Bay (진해만의 장기 수질변동 특성)

  • Kwon, Jung-No;Lee, Jangho;Kim, Youngsug;Lim, Jae-Hyun;Choi, Tae-Jun;Ye, Mi-Ju;Jun, Ji-Won;Kim, Seulmin
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.4
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    • pp.324-332
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    • 2014
  • In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

Retrieval of High Resolution Surface Net Radiation for Urban Area Using Satellite and CFD Model Data Fusion (위성 및 CFD모델 자료의 융합을 통한 도시지역에서의 고해상도 지표 순복사 산출)

  • Kim, Honghee;Lee, Darae;Choi, Sungwon;Jin, Donghyun;Her, Morang;Kim, Jajin;Hong, Jinkyu;Hong, Je-Woo;Lee, Keunmin;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.34 no.2_1
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    • pp.295-300
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    • 2018
  • Net radiation is the total amount of radiation energy used as a heat flux for the Earth's energy cycle, and net radiation from the surface is an important factor in areas such as hydrology, climate, meteorological studies and agriculture. It is very important to monitoring the net radiation through remote sensing to be able to understand the trend of heat island and urbanization phenomenon. However, net radiation estimation using only remote sensing data is generally causes difference in accuracy depending on cloud. Therefore, in this paper, we retrieved and monitored high resolution surface net radiation at 1 hour interval in Eunpyeong New Town where urbanization using Communication, Ocean and Meteorological Satellite (COMS), Landsat-8 satellite and Computational Fluid Dynamics (CFD) model data reflecting the difference in building height. We compared the observed and estimated net radiation at the flux tower. As a result, estimated net radiation was similar trend to the observed net radiation as a whole and it had the accuracy of RMSE $54.29Wm^{-2}$ and Bias $27.42Wm^{-2}$. In addition, the calculated net radiation showed well the meteorological conditions such as precipitation, and showed the characteristics of net radiation for the vegetation and artificial area in the spatial distribution.

Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Chuncheon, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 춘천시의 부지특성)

  • Jung, JinHoon;Kim, Ki Young
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.1-10
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    • 2014
  • To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity ($v_s$) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks ($D_b$), shear wave velocities of these basement rocks ($v_s^b$), average velocities of the overburden layer ($\bar{v}_s^s$), and the average velocity to a depth of 30 m ($v_s30$), were then derived from those models. The estimated values of $D_b$, $v_s^b$, $\bar{v}_s^s$, and $v_s30$ for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated $v_s30$ indicates that the lower altitude areas in Chuncheon are classified as $S_C$ (very dense soil and soft rock) or $S_D$ (stiff soil). To determine adequate proxies for $v_s30$, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between $v_s30$ and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.

Effects of Germanium-fortified Yeast on the Serum Lipids and Immune Cell Subset (게르마늄강화효모가 혈청지질 및 면역세포변화에 미치는 영향)

  • Lee, Sung-Hee;Oh, Sun-Woo;Rho, Sook-Nyung;Lee, Bog-Hieu;Lee, Hyun-Joo;Jin, Dong-Kyu
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.683-689
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    • 2006
  • This study was established to investigate the effect of germanium-fortified yeasts on the serum lipid composition and immune system of human body. All 50 subjects with the age range of $50{\sim}75$ were entered in this clinical trial for 6 months. The effects were determined by the proliferative responses of immune-mediated cells, T-cell, B-cell and NK-cell during daily supplementation with/without germanium-fortified yeast. The results of hematology and blood chemistry didn't show any significant differences during administration periods. Serum lipid compositions also didn't show any significant differences during administration periods except triglyceride (TG) and VLDL-cholesterol. TG and VLDL-cholesterol levels were increased significantly by the consumption of germanium-fortified yeast (p<0.05). Immune mediated T-celt and NK-cell didn't increased in both control and test group supplemented with germanium fortified yeast, while B-cell increased in the germanium fortified yeast group after 8 week (p<0.05). Also $TNF-{\alpha}$ increased in the group of germanium fortified yeast after 8 week (p<0.05) but not in the control group. From the above results, germanium fortified yeast is expected to be useful on the improvement of the cellular immune response and protection of organs from various chronic diseases.

The Sensitivity Analysis according to Observed Frequency of Daily Composite Insolation based on COMS (관측 빈도에 따른 COMS 기반의 일 평균 일사량 산출의 민감도 분석)

  • Kim, Honghee;Lee, Kyeong-Sang;Seo, Minji;Choi, Sungwon;Sung, Noh-Hun;Lee, Darae;Jin, Donghyun;Kwon, Chaeyoung;Huh, Morang;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.32 no.6
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    • pp.733-739
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    • 2016
  • Insolation is an major indicator variable that can serve as an energy source in earth system. It is important to monitor insolation content using remote sensing to evaluate the potential of solar energy. In this study, we performed sensitivity analysis of observed frequency on daily composite insolation over the Korean peninsula. We estimated INS through the channel data of Communication, Ocean and Meteorological Satellite (COMS) and Cloud Mask which have temporal resolution of 1 and 3 hours. We performed Hemispherical Integration by spatial resolution for meaning whole sky. And we performed daily composite insolation. And then we compared the accuracy of estimated COMS insolation data with pyranometer data from 37 points. As a result, there was no great sensitivity in the daily composite INS by observed frequency of satellite that accuracy of the calculated insolation at 1 hour interval was $28.6401W/m^2$ and 3 hours interval was $30.4960W/m^2$. However, there was a great difference in the space distribution of two other INS data by observed frequency of clouds. So, we performed sensitivity analysis with observed frequency of clouds and distinction between the two other INS data. Consequently, there was showed sensitivity up to $19.4392W/m^2$.

Methodologies for Enhancing Immersiveness in AR-based Product Design (증강현실 기반 제품 디자인의 몰입감 향상 기법)

  • Ha, Tae-Jin;Kim, Yeong-Mi;Ryu, Je-Ha;Woo, Woon-Tack
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.2 s.314
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    • pp.37-46
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    • 2007
  • In this paper, we propose technologies for enhancing the immersive realization of virtual objects in AR-based product design. Generally, multimodal senses such as visual/auditory/tactile feedback are well known as a method for enhancing the immersion in case of interaction with virtual objects. By adapting tangible objects we can provide touch sensation to users. A 3D model of the same scale overlays the whole area of the tangible object so the marker area is invisible. This contributes to enhancing immersion. Also, the hand occlusion problem when the virtual objects overlay the user's hands is partially solved, providing more immersive and natural images to users. Finally, multimodal feedback also creates better immersion. In our work, both vibrotactile feedback through page motors, pneumatic tactile feedback, and sound feedback are considered. In our scenario, a game-phone model is selected, by way of proposed augmented vibrotactile feedback, hands occlusion-reduced visual effects and sound feedback are provided to users. These proposed methodologies will contribute to a better immersive realization of the conventional AR system.