• Title/Summary/Keyword: L-Shaped

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Effect of Plan Irregularity and Beam Discontinuity on Structural Performances of Buildings under Lateral Loadings

  • Islam, Md. Rajibul;Chakraborty, Sudipta;Kim, Dookie
    • Architectural research
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    • v.24 no.2
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    • pp.53-61
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    • 2022
  • Irregularities in the structure are crucial factors in screening structural vulnerability under extreme loadings. Numerical analyses were carried out considering wind and seismic loadings for four structures with discrete irregularity: continuous and discontinuous beams with varied story levels, and L-shaped irregular buildings. Structural responses such as maximum displacements, bending moments, axial forces, torsions, and story drifts are evaluated as per the criteria and limits defined by ACI 318. The outcomes indicate that the frame system with beam discontinuity on the upper half of the height exhibits the best structural performance. The results also indicate that the asymmetrical design of the L-shaped model makes it more susceptible to damage when subjected to strong lateral loading conditions.

Cytological Evolution in the Genus Lycoris (Amarylidaceae)

  • Tae, Kyoung-Hwan;Ko, Sung-Chul
    • Journal of Plant Biology
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    • v.39 no.3
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    • pp.209-214
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    • 1996
  • Cytological characters of ten taxa of the genus Lycoris were investigated to illustrate their chromosomal evolution. The fusion theory was more appropriate than the fission theory. From the viewpoint of the fusion theory L. sanguinea group, diploids with R-shaped chromosomes was the most primitive and they might have diverged into two directions, the diploids with V+R shaped chromosomes and the triped with V+R shaped chromosomes via triploids with only R-shaped chromosomes.

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Structural Design and Construction for Tall Damped Building with Irregularly-Shaped Plan and Elevation

  • Yamashita, Yasuhiko;Kushima, Soichiro;Okuno, Yuuichirou;Morishita, Taisei
    • International Journal of High-Rise Buildings
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    • v.7 no.3
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    • pp.255-264
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    • 2018
  • This paper introduces three distinctive means for the use of a 189-meter high damped structure ensuring safety against earthquake: 1. Realization of L-shaped elevational structural planning: The bottom and top of the tower have belt trusses and hat trusses respectively to restrain the bending deformation. Furthermore, large-capacity oil dampers (damping force 6,000 kN) are installed in the middle part of the tower to restrain the higher-mode deformation. 2. Realization of L-shaped planar structural planning: We devised a means of matching the centers of gravity and rigidity by adjusting planar rigidity. Moreover, viscous damping devices are located at the edges of the L-shaped plan, where torsional deformation tends to be amplified. We call this the "Damping Tail" system. 3. Composite foundation to equalize deformations under different loading conditions: We studied the vertical and horizontal deformations using sway-rocking and 3D FEM models including the ground, and applied multi-stage diameter-enlarged piles to the tower and a mat foundation to the podium to keep the foundations from torsional deformations and ensure structural safety.

Stuides on the Cutting Methods of the Self-feeding Type Combine -on the Mixed Cutting Method (1)-on the Mixed Cutting Method(I) (자탈형 콤바인의 예취작업법에 관한 연구 -혼합예취법을 중심으로 (제1보)-)

  • 최복연
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.18 no.2
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    • pp.4096-4104
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    • 1976
  • This experiment was carried out to investigate the efficient turning method which will be able to use every cutting methods, to calculate the width of the center field which must transpose from rotary cutting method to return cutting method, to investigate the effects of L/W and unit field on the operation efficiency. The results are summarized as follows: 1. In case of cutting in the outer field, the efficient turning method is the "$\alpha$" type turning method (half U-shaped turning method) at the first rotation, is the "$\beta$" type turning method (T-shaped turning method) at the second to fourth rotation. 2. In case of cutting in the inner field, the efficient turning method which takes the least turning time is the "a" type turning method ($\Delta$-shaped turning method). 3. The width of the center field (W') changes by the length-width ratio (L/W) and width (W), W' is 9.0m in case that L/W is 2.5 and W is 30m. 4. The larger L/W and area of unit field (A) become, the more operation efficiency (E) increases, and the limits that E is affected signicantly by L/W is 2 to 3.5 and A is within 5,000$m^2$. within 5,000$m^2$.

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Analysis of the Bottom Groove in L-shaped Profile Ring Rolling (L형상 프로파일 링롤링 공정의 하부면 그루브 결함 분석)

  • Oh, I.Y.;Hwang, T.W.;Kang, P.G.;Moon, Y.H.
    • Transactions of Materials Processing
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    • v.27 no.5
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    • pp.289-295
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    • 2018
  • The profile ring rolling process can realize various ring shapes unlike conventional rectangular cross-sectional ring products. In this paper, the defective groove in the bottom surface of L-shaped ring products was analyzed. Grooves are generated by non-uniform external forces due to profile main roll and initial blank shape. Process parameters such as the motion of dies and working temperature were determined. Mechanism of groove formation was analyzed by FE simulation on the basis of local external forces acting on the blank. Analysis results were similar to the groove actually occurring in the production line. Based on results of the analysis, two solutions were proposed for the groove. The position of the base plate supporting the blank was adjusted and edge length of the main roll was extended to suppress growth of grooves. It has been verified that groove was improved by applying two proposed methods in the shop-floor.

The Study of Stiffness Evaluation Technique for L, T Shaped Joint Structures Using Normal Modes Analysis with Lumped Mass (모드해석을 이용한 L, T 자형 구조물의 결합 강성 평가 방법에 대한 연구)

  • Hur, Deog-Jae;Jung, Jae-Yup;Cho, Yeon;Park, Tae-Won
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.975-983
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    • 1999
  • This paper describes the dynamic characteristics of the joint structures in case of using the simplified beam model in the F. E. analysis. The modeling errors, when replace the shell with the beam, are investigated through F. E. normal modes analysis. Normal mode analysis were performed to obtain the natural frequencies of the L and T shaped joints with various type of channels. The results were analyzed to access the effects of the models on the accuracy of F.E. analysis by identifying the geometric factors which cause the error. The geometric factors considered are joint angle, channel length, thickness and area ratio of the hollow section to the filled one. The joint stiffness evaluation technique is developed in this study using normal modes analysis with Lumped Mass. With this method, the progressively improved results of F. E. analysis are obtained using the simplified beam model. The static and normal modes analysis are performed with the joint stiffness values obtained by the Kazunori Shimonkakis' virtual stiffness method and the proposed method and these simplified modeling errors are compared.

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Quality Characteristics of Kochujang Meju Prepared with Aspergillus Species and Bacillus subtilis

  • Oh, Byoung-Hak;Kim, Yong-Suk;Jeong, Pyeong-Hwa;Shin, Dong-Hwa
    • Food Science and Biotechnology
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    • v.15 no.4
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    • pp.549-554
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    • 2006
  • To standardize a manufacturing method and improve the quality of traditional kochujang, eight-types of meju with different shapes (brick, grain) were prepared using Aspergillus oryzae (A.o) or Aspergillus sojae (A.s) alone or in combination with Bacillus subtilis (B.s). The physicochemical characteristics and enzyme activities of the various meju were compared during fermentation for 12 days at $28^{\circ}C$. The moisture content of both the brick- and grain-shaped meju were gradually decreased from an initial content of 50.47 to 54.89% to a content of 12.91 to 16.25% on day 12 of fermentation. The neutral protease activities of the brick-shaped meju ranged from $1.19{\pm}0.12$ to $1.25{\pm}0.28\;unit/mL$, and were similar for all treatments. The ${\alpha}$-amylase activities in A.s+B.s treatment of brick-shaped and grain-shaped meju were the highest, $11{\pm}0.6$ and $9{\pm}0.7\;unit/mL$, respectively. The ${\beta}$-amylase activities ranged from $1.53{\pm}0.01$ to $1.56{\pm}0.02\;unit/mL$, and were similar for all treatments. The amino type nitrogen content of A.o+B.s brick-shaped meju was the highest, $0.39{\pm}0.03%$. We confirmed that the brick-shaped meju prepared with A. oryzae and B. subtilis could be used to prepare traditional kochujang to improve the quality of the product.

A comparative study between the new model and the current model for T-shaped combined footings

  • Garay-Gallegos, Jesus Rafael;Luevanos-Rojas, Arnulfo;Lopez-Chavarria, Sandra;Medina-Elizondo, Manuel;Aguilera-Mancilla, Gabriel;Garcia-Canales, Edith
    • Geomechanics and Engineering
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    • v.30 no.6
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    • pp.525-538
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    • 2022
  • This paper presents a more general model for T-shaped combined footings that support two columns aligned on a longitudinal axis and each column provides an axial load and two orthogonal moments. This model can be applied to the following conditions: (1) without restrictions on its sides, (2) a restricted side and (3) two opposite sides restricted. This model considers the linear soil pressure. The recently published works have been developed for a restricted side and for two opposite sides restricted by Luévanos-Rojas et al. (2018a, b). The current model considers the uniform pressure distribution because the position of the resultant force coincides with the center of gravity of the surface of the footing in contact with the soil in direction of the longitudinal axis where the columns are located. This paper shows three numerical examples. Example 1 is for a T-shaped combined footing with a limited side (one column is located on the property boundary). Example 2 is for a T-shaped combined footing with two limited opposite sides (the two columns are located on the property boundary). Example 3 is for a T-shaped combined footing with two limited opposite sides, one column is located in the center of the width of the upper flange (b1/2=L1), and other column is located at a distance half the width of the strip from the free end of the footing (b2/2=b-L1-L). The main advantage of this work over other works is that this model can be applied to T-shaped combined footings without restrictions on its sides, a restricted side and two opposite sides restricted. It also shows the deficiencies of the current model over the new model.

A fundamental study on the minimize wear of slurry shield TBM sludge bend pipe (이수식 쉴드 TBM 배니곡관 마모 최소화를 위한 기초 연구)

  • Soo-Jin Lee;Hyeon-Do Kim;Yong-Woo Kim;Sang-Hwan Kim
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.3
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    • pp.243-254
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    • 2024
  • Currently, due to industrial development in domestic regions, buildings are saturated not only in major city centers but also in surrounding urban areas. Accordingly, people's attention has focused on underground spaces, and tunnels are being widely used, especially in urban development. Research on tunnels and tunnel excavation methods is actively underway. However, there is a lack of research on the wear and tear problems of sludge discharge pipes when using a slurry shield TBM. Therefore, in this paper, the L-shaped bend pipe used in the existing sludge discharge pipe was transformed into a T-shaped bend pipe to move sludge. As a result, it was confirmed that compared to the L-shaped bend pipe, the impact of the T-shaped bend pipe on the bend pipe when discharging sludge was reduced. Based on these results, it is expected that wear of the sludge discharge pipe can be minimized by using a T-shaped bend pipe when using slurry shield TBM equipment. This is expected to ultimately lead to economic benefits, such as reducing costs due to replacement of curved pipes or additional welding during tunnel construction.

Improvement of free-space optical interconnection efficiency by using circular aperture CGH

  • Shin, Chang-Mok;Seo, Dong-Hoan;Cho, Kyu-Bo;Kim, Cheol-Su;Lee, Ha-Woon;Kim, Soo-Joong
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.9-11
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    • 2002
  • We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

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