• 제목/요약/키워드: Wedges

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Out-of-plane performance of infill masonry walls reinforced with post-compressed wedges under lateral-concentrated push load

  • Sanghee Kim;Ju-Hyun Mun;Jun-Ryeol Park;Keun-Hyeok Yang;Jae-Il Sim
    • Earthquakes and Structures
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    • v.26 no.6
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    • pp.489-499
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    • 2024
  • Infill masonry walls are vulnerable to lateral loads, including seismic, wind, and concentrated push loads. Various strengthening metal fittings have been proposed to improve lateral load resistance, particularly against seismic loads. This study introduces the use of post-compressed wedges as a novel reinforcement method for infill masonry walls to enhance lateral load resistance. The resistance of the infill masonry wall against lateral-concentrated push loads was assessed using an out-of-plane push-over test on specimens sized 2,300×2,410×190 mm3. The presence or absence of wedges and wedge spacing were set as variables. The push-over test results showed that both the unreinforced specimen and the specimen reinforced with 300 mm spaced wedges toppled, while the specimen reinforced with 100 mm spaced wedges remained upright. Peak loads were measured to be 0.74, 29.77, and 5.88 kN for unreinforced specimens and specimens reinforced with 100 mm and 300 mm spaced wedges, respectively. Notably, a tighter reinforcement spacing yielded a similar strength, as expected, which was attributed to the increased friction force between the masonry wall and steel frame. The W-series specimens exhibited a trend comparable to that of the displacement ductility ratio. Overall, the findings validate that post-compressed wedges improve the out-of-plane strength of infill masonry walls.

Late Pleistocene Lowstand Wedges on the Southeastern Continental Shelf of Korea (Korea Strait)

  • Yoo D. G.;Park S. C.;Park K. S.;Sunwoo D.;Han H. S.
    • 한국석유지질학회:학술대회논문집
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    • spring
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    • pp.15-21
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    • 1998
  • Sparker profiles and sediment cores collected from the Korea Strait show a distinct pattern of stacked prograding wedges consisting of three distinct units. These wedges are interpreted as the lowstand deposits formed during glacioeustatic sea-level lowstands. Repeated sea-level falls during late Pleistocene with high sediment discharge from the paleo-Nakdong River system resulted in the formation of thick lowstand wedges.

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Effects of a Heel Wedge on the Knee Varus Torque During Walking (보행 시 무릎관절 내번토크에 미치는 후족왯지의 영향)

  • 정임숙;김사엽;김영호;정도영;권오윤
    • Journal of Biomedical Engineering Research
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    • v.25 no.4
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    • pp.289-293
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    • 2004
  • In the present study, knee varus torque and mediolateral accelerations were measured using the three-dimensional motion analysis system and a linear accelerometry in odor to determine the effect of heel wedges during walking. Wedges were inclined with 10$^{\circ}$ and 15$^{\circ}$ in medial and lateral directions respectively Both knee varus torques and mediolateral accelerations showed two distinct positive peaks in loading response and preswing. Medial wedges resulted in significantly increased both knee varus torque and lateral acceleration in loading response, compared with the barefoot walking(p<0.05). On the other hand, lateral wedges decreased them in loading response(p<0.05). This became more significant for more inclined wedges. However, no significant correlations were found between knee varus torque and lateral acceleration according to the angle of heel wedges in preswing. From this study, it was found that a lateral wedge would be helpful to treat osteoarthritis, decreasing knee varus torque in loading response. In addition, lateral acceleration of the knee joint might be an alternative to determine the effect of wedges and the alignment of the knee joint during walking, instead of measuring knee torque by the three-dimensional motion analysis.

The Effects of Toe Wedges on the Spatiotemporal Gait Parameters of Adolescents with Spastic Diplegic Cerebral Palsy (발가락 벌림 교정기가 청소년기 경직형 양하지 뇌성마비의 보행에 미치는 영향)

  • Jang, Jung-Jae;Jung, Sun-Hye;Kim, Myung-Jong;Song, Sun-Hae;Lee, Dong-Geon;Lee, Seung-Hoo;Jang, Na-Young;Choi, Ji-Won;Ha, Sun-Young;Ha, Shin-Ho;Hong, Soung-Kyun;Lee, Gyu-Chang
    • PNF and Movement
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    • v.17 no.2
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    • pp.237-243
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    • 2019
  • Purpose: The purpose of the present study was to investigate the effects of toe wedges on the gait ability of adolescents with spastic diplegic cerebral palsy. Methods: Six adolescents with spastic diplegic cerebral palsy participated in this study. During the participants walked with- and without toe wedges, the gait ability was analyzed using the electronic walkway system. Gait parameters, including velocity, cadence, step length, stride length, single support time, and double support time, were collected and analyzed. Results: When the participants walked with toe wedges, there were significant improvements in gait velocity, cadence, and double support time compared to those without toe wedges (p<0.05). However, there were no significant differences in step length, stride length, and single support time. Conclusion: Toe wedges may have a positive effect on the gait ability of adolescents with spastic diplegic cerebral palsy. However, it is necessary to conduct high-quality studies to identify the effects of toe wedges.

A Study of the Anchorage loss of Ground Anchor Using Spacing Apparatus and Spring (간격유치장치를 이용한 어스앵커 인장에 관한 연구)

  • Jeong, Sang-Min;Park, Young-Keun;Park, Moo-Kon;Kim, Kwang-Eok;Lee, Keun-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.5 no.4 s.18
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    • pp.139-144
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    • 2005
  • A ground anchor system is used as a load carrying element in soil work. The conventional systems with ground anthers bring about the anchorage loss of wedges when anchors are installed for the support of soil structures. Hence we developed the new type of anchor system using both the spacing apparatus and spring (length 60mm, diameter 6mm). In this system, we tan directly check the condition of wedges and PS strands and modify the problems with the slip and anchorage of wedges under construction. For demonstrating the superiority of this system, we carried out a series of the laboratory test. Consequently, we can obtain satisfactory result (18.99$\%$ reduction to the loss of conventional systems). Moreover, the replacement of wedges is easy and simple when retensioning of strands.

Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator

  • Zabihzadeh, Mansour;Birgani, Mohammad Javad Tahmasebi;Hoseini-Ghahfarokhi, Mojtaba;Arvandi, Sholeh;Hoseini, Seyed Mohammad;Fadaei, Mahbube
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1685-1689
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    • 2016
  • Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended.

Comparison of Carries and Run Distance with Wedge Angle in Golf Running Approach (골프 런닝 어프로치에서 웨지 각도에 따른 캐리와 런 거리 비교)

  • Ha, Su Jin;Lee, Ki Chung;Seong, Keum Ju
    • Korean Journal of Applied Biomechanics
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    • v.29 no.4
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    • pp.213-217
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    • 2019
  • Objective: The purpose of this study was to investigate the ratio of carrie's and run's distance in golf running approach using 52° and 48° wedges. Method: 2 women's professional golfers from the LKPGA were given the running approach in the 5 m, 10 m, 15 m respectively. The variables were analyzed through a golf analyzer and actual measurement. Results: If you send 5 m with 52° and 48° wedges, the ball run about 5 m, 10 m respectively, if you carry 10 m with 52° and 48° wedges, the ball run about 10 m, 13 m respectively. And if you carry 15 m with 52° and 48° wedges, the ball run about 13 m, 15 m respectively. Conclusion: Based on the results, if you are confident in distance, if you choose the club properly and if you are confident, if you try to send the correct distance to the hole cup, then you will have a more confident approach, which will lead to better results.

Nonlinear analysis of stability of rock wedges in the abutments of an arch dam due to seismic loading

  • Mostafaei, Hasan;Behnamfar, Farhad;Alembagheri, Mohammad
    • Structural Monitoring and Maintenance
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    • v.7 no.4
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    • pp.295-317
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    • 2020
  • Investigation of the stability of arch dam abutments is one of the most important aspects in the analysis of this type of dams. To this end, the Bakhtiari dam, a doubly curved arch dam having six wedges at each of its abutments, is selected. The seismic safety of dam abutments is studied through time history analysis using the design-based earthquake (DBE) and maximum credible earthquake (MCE) hazard levels. Londe limit equilibrium method is used to calculate the stability of wedges in abutments. The thrust forces are obtained using ABAQUS, and stability of wedges is calculated using the code written within MATLAB. Effects of foundation flexibility, grout curtain performance, vertical component of earthquake, nonlinear behavior of materials, and geometrical nonlinearity on the safety factor of the abutments are scrutinized. The results show that the grout curtain performance is the main affecting factor on the stability of the abutments, while nonlinear behavior of the materials is the least affecting factor amongst others. Also, it is resulted that increasing number of the contraction joints can improve the seismic stability of dam. A cap is observed on the number of joints, above which the safety factor does not change incredibly.

Numerical simulation of wave slamming on wedges and ship sections during water entry

  • Ma, Zhihua;Qian, Ling
    • Ocean Systems Engineering
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    • v.8 no.2
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    • pp.183-199
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    • 2018
  • The open source software OpenFOAM is utilised to simulate the water entry and hydrodynamic impact process of 2D wedges and ship hull sections. Incompressible multiphase flow solver interDyMFoam is employed to calculate the free fall of structure from air into water using dynamically deforming mesh technique. Both vertical and oblique entry of wedges of various dead-rise angles have been examined. A convergence study of dynamics as well as kinematics of the flow problem is carried out on successively refined meshes. Obtained results are presented and compared to the experimental measurements showing good agreement and reasonable mesh convergence of the solution.

Sound Propagation over Multiple Wedges and Barriers

  • Kim, Hyun-Sil;Kim, Jae-Sueng;Kang, Hyun-Ju;Kim, Bong-Ki;Kim, Sang-Ryul
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.2E
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    • pp.44-50
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    • 2004
  • A theoretical formula that is based on the geometrical theory of diffraction (GTD) is proposed for computing sound diffraction by multiple wedges, barriers, and polygonal-like shapes. The formula can treat both convex and concave edges, where edges mayor may not be inter-connected. Comparisons of theoretical predictions with other results done by the BEM or experiments for scaled model confirm the accuracy of the present formula. Numerical examples such as double wedges and doubly inclined barrier show that when there exist several diffraction paths for given source and receiver positions, the insertion loss is dominated by the diffraction associated with the shortest propagation path.