• Title/Summary/Keyword: Wedge Angle

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A Study on the Wedge Angle of the Rail Clamp according to the Design Wind Speed Criteria Change

  • Lee Jung-Myung;Han Dong-Seop;Han Geun-Jo;Jeon Young-Hwan
    • Journal of Navigation and Port Research
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    • v.29 no.7
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    • pp.641-646
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    • 2005
  • In cargo-working, it unavoidably happens that the quay crane slip along the rail and the container move from side to side. Especially, they involve a lot of risk in bad weather. The rail clamp is a mooring device to prevent that the quay crane slips along the rail due to bad weather or the wind blast while the quay crane do the cargo-working And it will play a greater role in port container terminal integration and automation To design the wedge type rail clamp, it is very important to determine the wedge angle. In this study, we expect that the design wind speed of the quay crane will change over 16m/s. Assuming that the design wind speed is 40m/s, we determined the proper wedge angle of the wedge type rail clamp for the 50ton class quay crane.

The Results of the First Ray Forefoot Osteotomy Using Low Profile Wedge Plate without a Bone Grafting for Pes Planus Correction (제 1열 전족부 절골술을 통한 평발 교정에 있어 골이식 없이 사용한 소형 쐐기형 금속판의 치료 결과)

  • Choi, Jun Young;Shin, Myung Jin;Suh, Jin Soo
    • Journal of Korean Foot and Ankle Society
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    • v.21 no.1
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    • pp.7-11
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    • 2017
  • Purpose: We retrospectively analyzed the radiographic and clinical results after the first ray of forefoot osteotomy using low profile wedge plate without additional cancellous bone grafting for pes planus correction. Materials and Methods: Twenty-four patients were enrolled in this study. Medial cuneiform opening wedge osteotomy was performed in 12 patients (Cotton osteotomy, group C) and first metatarsal base osteotomy was performed in 12 patients (group MT). Results: On average, the wedge size was 5.61 mm (5~6 mm). The mean time to radiographic union was 3.18 and 3.27 months in groups C and MT, respectively. Postoperative talonavicular coverage angle, talo-first metatarsal angle (anteroposterior), talo-first metatarsal angle (lateral), talo-calcaneal angle (lateral), medial cuneiform height, and American orthopaedic foot, as well as ankle society midfoot scale were significantly improved in both groups. Nonunion, delayed union or fixation failure was not presented in our series. Conclusion: We have shown that low profile wedge plate was effective in the case of first ray forefoot osteotomy for pes planus correction without any additional cancellous bone grafting.

A Study on Wedge Angles of Wedge-type Rail Clamp for Preventing Jaw from Rotating (쐐기형 레일 클램프에서 조(jaw)의 회전을 방지하기 위한 적정 쐐기각에 대한 연구)

  • Shim J. J.;Lee S. W.;Han D. S.;Park J. S.;Jeon Y. H.;Lee H.;Han G. J.;Ahn C. W.
    • Journal of Navigation and Port Research
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    • v.29 no.8 s.104
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    • pp.735-740
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    • 2005
  • In this paper, we designed a wedge type rail-clamp which can protect container crane from sudden wind blast with constant clamping force regardless of the operating period. When we design wedge type rail clamp, it is important to determine an angle of wedge which prevent rotating of jaw and for smooth operation when wind blows. Therefore, this paper suggest a process to decide an angle of wedge within proper range obtained by experimental analysis as well as FEA of the wedge type rail clamp. A model with $6^{\circ}$ wedge angle is the most proper model to use in rail clamp bemuse it generated satisfactory clamping force and rotating angle underdesign specification.

Creative Design of the Wedge Type Rail Clamp to set the Initial Clamping Force (초기압착력 설정을 위한 쐐기형 레일클램프의 창의적 설계)

  • Han, Dong-Seop;Kim, Yong;Lee, Seong-Wook;Han, Geun-Jo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.3
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    • pp.58-64
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    • 2007
  • The clamping force of a jaw pad is determined by the displacements of main part when two lockers are locked, after the clamping angle of a locker was set up in the wedge type rail clamp for a container crane. In this time, if the resistance of wedge frame generates due to several factors, the clamping angle of a locker to display the initial clamping force will be changed because of the reduction of displacement of extension bar. This resistance is determined by the eccentric distance between the roller and the wedge, and by the gap between the wedge frame and outer frame. In this study we measured the tensile force of both extension bar through the performance test of the prototype rail clamp in order to evaluate the effect of the resistance of wedge frame on the clamping force of the wedge type rail clamp.

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A Experimental Analysis on the Relationship between the Angle of a Locker and the Clamping Force of Wedge Type Rail Clamp (Locker의 물림각과 쐐기형 레일클램프의 압착력에 관한 실험적 고찰)

  • Han Dong-Seop;Shim Jae- Joon;Han Geun- Jo;Lee Kwon-Hee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.247-252
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    • 2005
  • The wedge type rail clamp has the operating mechanism: First, the jaw pad clamps a rail with small clamping force Next as the wind speed increases, the clamping force of the jaw pad is increased by the wedge. In order to design the wedge type rail clamp, we need to determine the proper wedge angle to minimize the sliding distance of a roller and the proper clamping angle of a locker to generate the initial clamping force of a jaw pad. The researches for the proper wedge angle have conducted, and in this study we conducted the investigation to determine the proper clamping angle of a locker in the rail clamp with wedge angle of $10^{\circ}$. Because the initial damping force of the jaw pad was determined by the clamping angle of the locker, in order to carry out the clamping force of a jaw pad, we measured the locking force applied to a locker with respect to the clamping angle of a locker, such as $3^{\circ},\;4^{\circ},\;5^{\circ},\;6^{\circ},\;$ using a pressure gauge, and compared the results with the FEA results.

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A Study on the Characteristics of the Acoustic Reflection of the Wedge Shaped Underwater Sound Absorptive Tile (쐐기형 수중음파 흡수타일의 음반사 특성 연구)

  • Kang, Sung-Oug;Hong, Woo-Young;Song, Yeong-Il;Lyu, Ki-Sang;Baek, Chil-Ki
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.3
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    • pp.45-50
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    • 1997
  • Four different wedge angle absorptive tiles were designed and made, and the magnitudes of the reflected acoustic fields by the wedge shaped underwater sound absorptive tiles were measured. The minimum magnitude was found at the angle of 30$^{\circ}$ and the maximum of it was found at the wedge angle of 120$^{\circ}$ from measured the reflected acoustic fields at the front sides of the tiles. The fact that as wedge angle of the absorptive tile increases, the reflection coefficient is increasing is verified. The measured reflected acoustic fields were not dependent on the frequency in the range of 10kHz~30kHz used in this experiment for the same wedge angle tile. The measured reflected acoustic fields at the back sides of the tiles show that they are independent from both type of the absorptive tiles and the frequencies used in the experiments. The measured values and the computed values by the numerical model for the reflected acoustic fields of the wedge shaped absorptive tiles are fairly well comparable with one another.

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DYNAMIC WEDGE의 임상 적용 가능성에 관한 고찰

  • 김영범;정세영;황웅구
    • The Journal of Korean Society for Radiation Therapy
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    • v.7 no.1
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    • pp.103-110
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    • 1995
  • Dynamic wedge system has been introduced to modify the beam profile and to make homogeneous isodose curves in the mass of irregular shape. Before the clinical use of dynamic wedge, several factors such as wedge transmission factor, dose profile, percent depth dose, and wedge angle have to be measured quantitatively. Film dosimetry is used to evaluate these factors in this study. A comparison of the result of the dynamic wedge to physical wedge system is made. A positive result for the application of the dynamic wedge to clinic is derived even though there is a limitation in accuracy of the dosimetry system used. To measure all factors quantitatively, more accurate dosimetry systems are required.

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The Comparative analysis of X-ray film on Lumbar Scoliosis and HNP by Barge Method (Barge 방식에 의한 요추부 척추측만증과 추간판 탈출증의 X-ray 비교분석)

  • Kim, Gyu-Sub
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.6 no.1
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    • pp.53-61
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    • 2011
  • Objective: The purpose of this study is to evaluate the disc block subluxation for lumbar scoliosis and herniation of nucleus pulpous (HNP). Methods: We used AP & Lateral view X-ray for patients. And we measured of disc wedge angle, vertebral body rotation to evaluate the typical and atypical disc block subluxation. Results: On the analysis of the lateral view X-ray, 4th lumbar intervertebral disc angle (I.V.D angle) showed $4^{\circ}$, $5^{\circ}$, $3^{\circ}$, $0^{\circ}$ in the cases. On the 4th lumbar analysis of the AP view X-ray, lumbar scoliosis showed right disc wedge angle was $11^{\circ}$ (case 1), $17^{\circ}$ (case 2) and left vertebral body rotation was 13mm, 6mm. Lumbar HNP showed left disc wedge angle was $5^{\circ}$ (case 3), $4^{\circ}$ (case 4) and left vertebral body rotation was 2mm, 4mm. Conclusions: Disc block subluxation has been in lumbar scoliosis, but not been in lumbar HNP.

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A Study on the Wedge Angle of the Rail Clamp according to the Change of the Design Wind Speed Criteria (설계풍속 상향조정에 따른 레일클램프의 쐐기각에 대한 연구)

  • Lee, Jung-Myung;Han, Dong-Seop;Lee, Seong-Wook;Shim, Jae-Joon;Han, Geun-Jo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.12 s.189
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    • pp.103-110
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    • 2006
  • The rail clamp is very important device to prevent that a container crane slips along a rail due to the wind blast as well as to locate the crane in the set position during an operating mode. Recently, the design wind speed criteria were intensified from the wind speed of 16m/s to 35m/s during an operating mode, and from 50m/s to 75m/s during a stowed mode in Korea, according to the 'Inspection Criteria for Facilities and Equipments in Port' reformed after typhoon 'Maemi'. In order to design the wedge type rail clamp for the reinforced design wind speed criteria of 35m/s, we carried out the finite element analysis of the rail clamp with respect to the wedge angle, and analyzed the relationship between the wedge angle and the sliding distance of the rail clamp.

Effects of Combined Wedge on Angle and Moment of Ankle and Knee Joint During Gait in Patients With Genu Varus

  • Yang, Hae Sun;Choi, Houng Sik
    • Journal of International Academy of Physical Therapy Research
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    • v.7 no.2
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    • pp.1025-1030
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    • 2016
  • The purpose of this study was to investigate the effects of combined wedge on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion of foot for genu varus among adult men during gait. This study was carried out with 10 adult men for genu varus in a motion analysis laboratory in J university. The subjects of the experiment were measured above 5cm width between the knees on contact of both medial malleolus of ankle while standing. The width of their knees in neutral position was measured without the inversion or eversion of the subtalar joint by the investigator. The subjects of the experiment were ten who were conducted randomly for standard insole, insole with $10^{\circ}$ lateral on rear foot wedge, insole at $10^{\circ}$lateral on rear foot and $5^{\circ}$ medial on fore foot wedge. Before and after intervention, changes on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion were measured. In order to compare analyses among groups; repeated one-way ANOVA and $Scheff{\acute{e}}$ post hoc test were used. As a result, combined wedge group was significantly decreased compared to control wedge group in terms of knee varus angle in mid-stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of ankle eversion moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of knee adduction moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge in terms of center of pressure excursion in whole stance(p<.05). The results of this study suggest that combined wedge for genu varus decreased ankle eversion moment and knee adduction moment upon center of pressure excursion. We hypothesize that combined wedge may also be effective in the protection excessive ankle pronation.