• Title/Summary/Keyword: concrete cover design

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Analysis of the Aesthetics of the Human Body Portrayed in Front Cover of Women's Magazines Prior to 1945 (1945년 이전 여성잡지 표지화에 나타난 인체미 분석)

  • Lee, Soon-Jae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.12 s.159
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    • pp.1737-1746
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    • 2006
  • The purpose of this study is to present a concrete image of the ideal beauty as shown in era preceding 1945 that effects the shaping of our aesthetic values; by analyzing its characteristics through the covers of women's magazines of that period, this research aims to promote the understanding of beauty of the human body. The scope of my research extends throughout the collection of women's magazines stored in the National Library and the Korea Magazine Information Center. The gathered research materials are: 5 kinds of Shin-Yeo-Sung (신여성), 51 kinds Yeo-Sung(여성) and 30 kinds of Ga-Jung-Ji-Woo(가정지우). The result of the research could be summarized as the followings. Before the 1920's in response to the violent opening, there was a trend of sticking to the traditional standard. In the 1920's, the prevalent images of women were meek and fragile. Japanese standard of beauty was explicitly indicated. In the 1930s, as Western movies started to be shown to the general public, western features were idealized and furthermore intelligence was required as a further condition. In the 1940s, preparation of the war led to encouragement of images of motherhood and natural beauty, and resistant to this trend led to pseudoclassicism.

Verification of the Torsional Amplification Factor for the Seismic Design of Torsionally Imbalanced Buildings (비틀림 비정형 건물의 내진설계를 위한 우발편심 비틀림 증폭계수 검증)

  • Lee, Kwang-Ho;Jeong, Seoung-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.14 no.6
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    • pp.67-74
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    • 2010
  • Because of the difference between the actual and computed eccentricity of buildings, symmetrical buildings will be affected by torsion. In provisions, accidental eccentricity is intended to cover the effect of several factors, such as unfavorable distributions of dead- and live-load masses and the rotational component of ground motion about a vertical axis. The torsional amplification factor is introduced to reduce the vulnerability of torsionally imbalanced buildings. The effect of the torsional amplification factor is observed for a symmetric rectangular building with various aspect ratios, where the seismic-force-resisting elements are positioned at a variable distance from the geometrical center in each direction. For verifying the torsional amplification factor in provisions, nonlinear reinforced concrete models with various eccentricities and aspect ratios are used in rock. The difference between the maximum displacements of the flexible edge obtained between using nonlinear static and time-history analysis is very small but the difference between the maximum torsional angles is large.

Applicability of UAV in Urban Thermal Environment Analysis (도시 내 열환경 분석에서 무인항공기의 활용가능성)

  • Kang, Da-In;Moon, Ho-Gyeong;Sung, Sun-Yong;Cha, Jae-Gyu
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.2
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    • pp.52-61
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    • 2018
  • Urban heat islands occur due to increases in the extent of artificial surfaces such as concrete, asphalt and high-rise buildings. In this regard, research into the use of satellite thermal infrared images for thermal environment analysis of urban areas is being carried out. However, such analysis of the characteristics of individual land cover with low-resolution satellite images suffers from limitations because land cover patterns in urban areas are complicated. Recently, UAV has been widely used, which can compensate for this limitation as it is able to acquire high-resolution images. In this paper, the accuracy of UAV infrared images is verified and the applicability of UAV in urban thermal environment analysis is examined by comparing the results with land surface temperatures from Landsat 8 thermal images. The results show a high positive correlation of temperature values at 0.95, and no statistically significant difference between the two groups. Comparisons of land surface temperature according to land cover showed that the largest difference observed was $4.63^{\circ}C$ in the Used area, and UAV images with small cell units reflected various surface temperatures. Furthermore, it was possible to analyze the surface temperatures of various green spaces such as wetlands and street tree areas, which can lower surface temperatures in urban areas, with street tree shadows reducing surface temperatures by about $4-6^{\circ}C$. UAV can easily and rapidly measure the surface temperature of urban areas and is able to analyze various types of green spaces. Thus, this is an effective tool for thermal environment analysis in urban areas to aid in the design or management of urban green spaces, as it can allow for land cover and the effects of the various green spaces.

Numerical Analysis on Liquefaction Countermeasure of Seabed under Submerged Breakwater Using Concrete Mat Cover (for Irregular Waves) (콘크리트매트 피복을 이용한 잠제하 해저지반에서의 액상화 대책공법에 관한 수치해석 (불규칙파 조건))

  • Lee, Kwang-Ho;Ryu, Heung-Won;Kim, Dong-Wook;Kim, Do-Sam;Kim, Tae-Hyung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.1
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    • pp.20-35
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    • 2017
  • In the case of the seabed around and under gravity structures such as submerged breakwater is exposed to a large wave action long period, the excess pore pressure will be significantly generated due to pore volume change associated with rearrangement soil grains. This effect will lead a seabed liquefaction around and under structures as a result of the decrease in the effective stress, and eventually the possibility of structure failure will be increased. The study of liquefaction potential for regular waves had already done, and this study considered for irregular waves with the same numerical analysis method used for regular waves. Under the condition of the irregular wave field, the time and spatial series of the deformation of submerged breakwater, the pore water pressure (oscillatory and residual components) and pore water pressure ratio in the seabed were estimated and their results were compared with those of the regular wave field to evaluate the liquefaction potential on the seabed quantitatively. Although present results are based on a limited number of numerical simulations, one of the study's most important findings is that a safer design can be obtained when analyzing case with a regular wave condition corresponding to a significant wave of the irregular wave.

A Study of Minimum Reinforcement Ratio of Singly Reinforced Beamy (단철근 보의 최소철근비에 대한 고찰)

  • Choi, Seung-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.396-402
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    • 2021
  • A cross section in RC flexural members must be designed to satisfy flexural strength and ductility requirements simultaneously. In design provisions, ductile behavior is ensured by a sufficient reinforcement ratio or depth of the neutral axis. If the reinforcement ratio is less than the balanced reinforcement ratio, ductile behavior is secured, and this value is theoretically the maximum reinforcement ratio. But for a cross section with less steel, brittle failure can occur regardless of ductile behavior because of unqualifying a cracking moment. Recently, designs with a minimum steel ratio have been increasing along with the use of high-strength material, so in design provisions, a minimum amount of reinforcement is suggested. In the KCI(2012) standard, a minimum amount of reinforcement was suggested in terms of strength of steel and concrete. But in the revised KCI(2017) standard, a minimum amount of reinforcement was suggested by a relationship between the design flexural strength and cracking moment indirectly. This code can reflect the effect of cover thickness, but a material model must be defined. Therefore, the minimum amount of reinforcement in KCI(2012) and KCI(2017) was examined, and a rational review method was studied by parametric analysis.

Cyclic Behavior of Wall-Slab Joints with Lap Splices of Coldly Straightened Re-bars and with Mechanical Splices (굽힌 후 편 철근의 겹침 이음 및 기계적 이음을 갖는 벽-슬래브 접합부의 반복하중에 대한 거동)

  • Chun, Sung-Chul;Lee, Jin-Gon;Ha, Tae-Hun
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.275-283
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    • 2012
  • Steel Plate for Rebar Connection was recently developed to splice rebars in delayed slab-wall joints in high-rise building, slurry wall-slab joints, temporary openings, etc. It consists of several couplers and a thin steel plate with shear key. Cyclic loading tests on slab-wall joints were conducted to verify structural behavior of the joints having Steel Plate for Rebar Connection. For comparison, joints with Rebend Connection and without splices were also tested. The joints with Steel Plate for Rebar Connection showed typical flexural behavior in the sequence of tension re-bar yielding, sufficient flexural deformation, crushing of compression concrete, and compression rebar buckling. However, the joints with Rebend Connection had more bond cracks in slabs faces and spalling in side cover-concrete, even though elastic behavior of the joints was similar to that of the joints with Steel Plate for Re-bar Connection. Consequently, the joints with Rebend Connection had less strengths and deformation capacities than the joints with Steel Plate for Re-bar Connection. In addition, stiffness of the joints with Rebend Connection degraded more rapidly than the other joints as cyclic loads were applied. This may be caused by low elastic modulus of re-straightened rebars and restraightening of kinked bar. For two types of diameters (13mm and 16mm) and two types of grades (SD300 and SD400) of rebars, the joints with Steel Plate for Rebar Connection had higher strength than nominal strength calculated from actual material properties. On the contrary, strengths of the joints with Rebend Connection decreased as bar diameter increased and as grade becames higher. Therefore, Rebend Connection should be used with caution in design and construction.

Axial Load Test of Prefabricated Composite Columns Using Bolt-connected Steel Angles (볼트접합 앵글을 사용한 합성기둥의 중심축 압축실험)

  • Kim, Hyeon Jin;Hwang, Hyeon Jong;Park, Hong Gun;Kim, Dong Kwan;Yang, Jong Min
    • Journal of Korean Society of Steel Construction
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    • v.29 no.2
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    • pp.147-158
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    • 2017
  • The present study focused on the structural performance of newly developed prefabricated composite columns (PSRC composite column) using bolt-connected steel angles. Concentric axial loading tests were performed for four 2/3 scaled PSRC column specimens and two conventional SRC column specimens. The test parameters were the spacing and sectional configurations of lateral reinforcement, and width-to-thickness ratio of steel angles. The test results showed that the axial load-carrying capacity and deformation capacity of the PSRC column specimens were comparable to those of the conventional SRC column specimens. Closely spaced steel plates and Z-shaped steel plates for lateral reinforcement increased the deformation capacity of the PSRC column specimens. The load-carrying capacity was greater than the prediction by current design codes. Numerical analysis was performed for the specimens. The results agreed well with the test results in terms of initial stiffness, load-carrying capacity, except for strength degradation due to cover concrete spalling.