• Title/Summary/Keyword: wind stability

Search Result 784, Processing Time 0.021 seconds

A Study on the Appearance Characteristic of Landscape Elements and Symbolic Elements Implied in Tablets - Focus on Korean Damyang Garden and Chinese Suzhou Garden - (편액에 함의된 경관 및 상징요소의 출현특성 - 한국의 담양원림과 중국의 소주원림을 중심으로 -)

  • Ham, Kwang-Min;Li, Shu-Hua;Zhang, Ya-Ping;Mitani, Toru;Zhang, Jun-Hua
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.34 no.4
    • /
    • pp.78-88
    • /
    • 2016
  • The comparative analysis result of appearance characteristic of landscape elements and symbolic elements implied by the tablets on the 16th century's Korean Damyang garden and Chinese Suzhou garden is as follows. First, among the landscape elements implied in the tablets, appearance rate of botanical factors appeared high in the gardens of both areas. Damyang garden displayed bamboo grove and natural forest around the garden, while Suzhou garden displayed artificial mountain(假山) created artificially and a variety of plants including lotus, bamboo, and pine surrounding it were associated with the significance of the tablets. On the other hand, climatic/celestial elements including the rain, wind, and the moon were associated with the tablets of Damyang garden, while the artificial factors such as the building, bridge, and book, etc. were mostly were associated with the tablets of Suzhou garden. Second, among the symbolic elements included in the tablets, ethical personality which is the basic virtue of a noble man(聖人), was the universal characteristic of the meditation world of the garden in both areas. However, a will for political stability was mostly associated with the tablets of Damyang garden, while the retrospect heart for the immortal was mostly associated with the signboard in Suzhou garden. It was concerned with political ideal and the thought of Confucianism respectively. Third, the symbolic elements that appeared frequently in the tablets of Damyang garden, "Ethics" and "Political stability", were associated with the scene atmosphere created by the climatic elements and celestial elements. On the contrary, the symbolic elements which most frequently appeared in the tablets of Suzhou garden, "Ethics", was associated with the symbolic significance of the plant. The invisible space of gardens was expanded by tablets in both areas.

정지궤도 통신해양기상위성의 기상분야 요구사항에 관하여

  • Ahn, Myung-Hwan;Kim, Kum-Lan
    • Atmosphere
    • /
    • v.12 no.4
    • /
    • pp.20-42
    • /
    • 2002
  • Based on the "Mid to Long Term Plan for Space Development", a project to launch COMeS (Communication, Oceanography, and Meteorological Satellite) into the geostationary orbit is undergoing. Accordingly, KMA (Korea Meteorological Administration) has defined the meteorological missions and prepared the user requirements to fulfill the missions. To make a realistic user requirements, we prepared a first draft based on the ideal meteorological products derivable from a geostationary platform and sent the RFI (request for information) to the sensor manufacturers. Based on the responses to the RFI and other considerations, we revised the user requirement to be a realistic plan for the 2008 launch of the satellite. This manuscript introduces the revised user requirements briefly. The major mission defined in the revised user requirement is the augmentation of the detection and prediction ability of the severe weather phenomena, especially around the Korean Peninsula. The required payload is an enhanced Imager, which includes the major observation channels of the current geostationary sounder. To derive the required meteorological products from the Imager, at least 12 channels are required with the optimum of 16 channels. The minimum 12 channels are 6 wavelength bands used for current geostationary satellite, and additional channels in two visible bands, a near infrared band, two water vapor bands and one ozone absorption band. From these enhanced channel observation, we are going to derive and utilize the information of water vapor, stability index, wind field, and analysis of special weather phenomena such as the yellow sand event in addition to the standard derived products from the current geostationary Imager data. For a better temporal coverage, the Imager is required to acquire the full disk data within 15 minutes and to have the rapid scan mode for the limited area coverage. The required thresholds of spatial resolutions are 1 km and 2 km for visible and infrared channels, respectively, while the target resolutions are 0.5 km and 1 km.

Uplift Bearing Capacity of Spiral Steel Peg for the Single Span Greenhouse (온실용 나선철항의 인발저항력 검토)

  • Lee, Bong Guk;Yun, Sung Wook;Choi, Man Kwon;Lee, Si Young;Moon, Sung Dong;Yu, Chan;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
    • /
    • v.23 no.2
    • /
    • pp.109-115
    • /
    • 2014
  • This study examined the uplift bearing capacity of spiral steel pegs according to the degree of soil compaction and embedded depth in a small-scaled lab test. As a result, their uplift bearing capacity increased according to the degree of soil compaction and embedded depth. The uplift bearing capacity under the ground condition of 85% compaction rate especially recorded 48.9 kgf, 57.9 kgf, 86.2 kgf and 116.6 kgf at embedded depth of 25 cm, 30 cm, 35 cm and 40 cm, respectively, being considerably higher than under other ground conditions. There were huge differences in the uplift bearing capacity of spiral steel pegs according to the compaction conditions of ground. Their maximum uplift bearing capacity was 116.6 kgf under the ground condition of 85% compaction rate and at embedded depth of 40 cm, and it is very high considering the data of spiral steel pegs. It is thus estimated that wind damage can be effectively reduced by careful maintenance of ground condition surrounding spiral steel pegs. In addition, spiral steel pegs will be able to make a contribution to greenhouse structural stability if proper installation methods are provided including the number and interval according to the types of greenhouse as well as fixation of plastic film. The findings of the study indicate that the optimal effects of spiral steel pegs for greenhouse can be achieved at embedded depth of more than 35cm and compaction degree of more than 85%. The relative density of the model ground in the test was 67% at compaction rate of 85%.

Motion Analysis of Light Buoys Combined with 7 Nautical Mile Self-Contained Lantern (7마일 등명기를 결합한 경량화 등부표의 운동 해석)

  • Son, Bo-Hun;Ko, Seok-Won;Yang, Jae-Hyoung;Jeong, Se-Min
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.5
    • /
    • pp.628-636
    • /
    • 2018
  • Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.