• Title/Summary/Keyword: Fixed Joint

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Behavior of Jointed Concrete Pavement by Box Culvert and Reinforced Slab (박스형 암거와 보강슬래브에 의한 줄눈 콘크리트 포장의 거동)

  • Park, Joo Young;Sohn, Dueck Su;Lee, Jae Hoon;Yan, Yu;Jeong, Jin Hoon
    • International Journal of Highway Engineering
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    • v.14 no.6
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    • pp.25-35
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    • 2012
  • PURPOSES : Hollows are easily made, and bearing capacity can be lowered near underground structures because sublayers of pavement settle for a long time due to difficult compaction at the position. If loadings are applied in this condition, distresses may occur in pavement and, as the result, its lifespan can decrease due to the stress larger than that expected in design phase. Although reinforced slab is installed on side of box culvert to minimize the distresses, length of the reinforced slab is fixed as 6m in Korea without any theoretical consideration. The purpose of this paper is investigating the behavior of concrete pavement according to the cover depth of the box culvert ad the length of the reinforced slab. METHODS : The distresses of concrete pavement slabs were investigated and cover depth was surveyed at position where the box culverts were located in expressways. The concrete pavements including the box culverts were modeled by finite element method and their behaviors according to the soil cover depth were analyzed. Wheel loading was applied after considering self weight of the pavement and temperature gradient of the concrete pavement slab at Yeojoo, Gyeonggi where a test road was located. After installing pavement joint at various positions, behavior of the pavement was analyzed by changing the soil cover depth and length of the reinforced slab. RESULTS : As the result, the tensile stress developed in the pavement slab according to the joint position, cover depth, and reinforced slab length was figured out. CONCLUSIONS : More reasonable and economic design of the concrete pavement including the box culvert is expected by the research results.

A Study on the Standard Joint Material and Reference Plane for the Standard of Construction in the Apartment - Joining Part between Gypsumboard and Windows - (공동주택 시공표준화를 위한 조립기준면 및 표준마무리재에 관한 연구 - 석고보드 마감재와 창호재의 접합부위를 중심으로 -)

  • Lim, Seok-Ho;Park, Keun-Soo;Lee, Ga-Kyung
    • Journal of the Korean housing association
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    • v.20 no.4
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    • pp.31-38
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    • 2009
  • In our country, the application of the design method of face to face dimension in wall-slab apartment has passed 10 years. So MC(Modular Coordination) design method has fixed in the design step to some degree. In Design and Work Execution of House the exclusive area of the apartment was calculated by face to face dimension. And the term of face to face dimension was known broadly to clients, construction company, etc. But design method of face to face dimension is not to simply extend the room size so far as wall depth in design process but to ensure the actual space should be considered with efficient use and assembly of building components. That is to say, Design method of face to face dimension is not to be defined by design step but to be related with construction and maintenance. However in construction process the point of face to face design method was not understood even now. So the purpose of this study was to extract the effect and question of face to face design method in construction process by survey of actual condition of structure and construction quality, and compare this result with existing construction method. The following project of this study is to survey of actual condition of interior components such as gypsum board, windows & doors etc. Therefore this study is to induce architectural long-life through architectural standardization construction and component's exchange, and, by the subject of the study on Apartment to have design guideline and basis for joining part between Gypsumboard and windows.

Treatment of Hamate Body Coronal Fracture (유구골 체부 관상면 골절의 치료)

  • Lee, Sang Hyun;Kim, Nu Ri;Jang, Jae Hoon;Ahn, Tae Young
    • Journal of Trauma and Injury
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    • v.27 no.3
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    • pp.57-62
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    • 2014
  • Purpose: A hamate body coronal fracture is well known as a very rare fracture in the carpal bones and is also hard to diagnose in initial stage due to the bone's architecture. We report our experience in treatment of such a fracture, and we present a review of the relevant literatures. Methods: Four patients who experienced hamate body coronal fractures from October 2006 to October 2013 were enrolled in this study. One patient also had an associated Capitate fracture, and two patients had associated dislocations of the $4^{th}$ metacarpal joint. We performed open reduction and mini-screw fixation on the four patients. In addition, a K-wire was fixed for the two patients with dislocations. Results: The average follow-up period was 24.5 months after surgery, and bone union was observed at the $8^{th}$ week after surgery. We confirmed that bone union had been completed for all the patients, and functional tests showed that joint motion was in the normal range without complications. Conclusion: When a patient has consistent pain on the ulnar side of the wrist, a hamate fracture should be suspected. Computer tomography is better than a simple X-ray scan for confirming the diagnosis of a hamate body coronal fracture. An open reduction and mini-screw fixation led to a good result.

Reliability Analysis of Temporary Structures Considering Uncertainty in Rotational Stiffness at Member Joints (부재 연결부 회전 강성의 불확실성을 고려한 가설 구조물의 신뢰성 해석)

  • Ryu, Seon-Ho;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.87-94
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    • 2019
  • This study deals with the reliability analysis approach of the temporary structure that can consider the uncertainty in rotational stiffness at the joints of the members, for which the semi-rigid connections are modelled as rotational spring and its coefficient is treated as a random variable following uniform distribution. In addition, this study introduces a computational procedure of the effective length coefficient for more accurate buckling load according to connection conditions of the supporting members attached to the joint. From the results of this study, it can be seen that the failure probability of the joint-hinge model (Case 1) presented in the design standard is higher than that of the practical model (Case 5) considering the rotational stiffness at the joints. This implies that the design standard leads to a conservative design of the temporary structure. The results also confirmed that the failure probability of the vertical member, i.e., the most critical member, can be further reduced when the base connection is provided with a fixed end. The comparative results between FORM, SORM and MCS further demonstrated that FORM can have a high level of numerical efficiency while ensuring the accuracy of the solution, compared with SORM and MCS. Based on these results, the proposed approach can be used as an accurate and efficient reliability analysis method of the three dimensional temporary structure.

Treatment of Transverse Patella Fracture with Minimally Invasive Load-Sharing Patellar Tendon Suture and Cannulated Screws (최소 침습 기법 슬개건 부하 분산 봉합술과 유관 나사못을 이용한 슬개골 횡골절의 치료)

  • Lee, Beom-Seok;Park, Byeong-Mun;Yang, Bong-Seok;Kim, Kyu-Wan
    • Journal of the Korean Orthopaedic Association
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    • v.56 no.6
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    • pp.540-545
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    • 2021
  • A transverse fracture is the most common type of displaced patella fracture requiring surgery. These fractures are commonly fixed with parallel Kirschner wires or screws that cross the fracture line, often with an additional tension band. Nevertheless, conventional fixation methods of patella fractures have prevalent complications caused by the protrusion of wires or pins. These complications necessitate additional surgery for hardware removal, increase medical cost, and can limit the function of the knee joint. This paper reports cases treated with a minimally invasive load-sharing percutaneous suture of the patella tendon. The procedure provides reliable fixation for transverse patella fractures, minimizes soft tissue injuries, preserves blood flow, and reduces postoperative pain. In addition, the procedure also reduces the irritation and pain caused by the internal fixture, thereby reducing the risk of restricted knee joint movement.

Evaluation of Pants Embedded with Motion Adaptable 3D Printing Fall Impact Protective Pads (동작 가변적 3D 프린팅 낙상보호패드가 통합된 팬츠의 평가)

  • Lee, Jinsuk;Park, Junghyun;Lee, Jeongran
    • Journal of Fashion Business
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    • v.26 no.2
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    • pp.143-155
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    • 2022
  • The purpose of this study was to develop protective clothing that could alleviate fall impacts. Fall impact protection pants for elderly women were designed, and motion adaptable hip pads and knee pads printed by 3D printing were integrated into the pants and evaluated. First, the design of the fall impact protection pants with variable motion was semi-loose fitting pants that could be worn and detached from the protective pad. A pad pocket was made in the lining inside the pants so that the protective pad could be fixed to the protective area. Second, in the evaluation of the appearance of the fall impact protection pants, the wearer group had a good score of 4.60 or higher for all questions on color, material, ease, and fit. In the evaluation of the insertion method of the protective pad, the flexibility of the pad, and the weight of the pad, the subjects' scores were 4.30~4.80. The fit of the fall impact protection pants was excellent in the texture and elasticity of the outside and inside of the pants. There was no discomfort due to the pad(4.60), and no difficulty in movement during wearing activities was reported. During squatting, it was evaluated as 4.80, indicating that the motion adaptable hip joint and knee pads were highly effective during operation.

A modified trans-anconeus approach to facilitate fixation of a posterior radial head fracture: a cadaveric feasibility study

  • Ahmed Mohamed Desouky;Ahmed Naeem Atiyya;Mohamed Elbishbishi;Marwa Mohamed El Sawy
    • Anatomy and Cell Biology
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    • v.56 no.1
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    • pp.39-45
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    • 2023
  • Fixation of radial head fracture with minimally invasive posterior approach remains a significant challenge. The aim of this study was to determine the feasibility of trans-anconeus posterior elbow approach and to observe lateral ulnar collateral ligament (LUCL) in extended elbows. This cadaveric study was performed in twenty upper limbs of fresh fixed adult male cadavers. An oblique incision was made in the middle segment of anconeus until the lateral ligament complex and the joint capsule had been revealed. A deep dissection was explored to observe the anatomical relationship of the LUCL to the anconeus. Measurements of the LUCL were recorded while the elbow was fully extended. The mean distance between the edge of the radial head and the proximal insertion of the LUCL was 13.3 mm (11.5-16.2 mm); the mean distance between the edge of the radial head and the distal insertion of the LUCL was 20.9 mm (19.2-23.4 mm); the distance between the edge of the radial head and the distal edge of the annular ligament was 11.2 mm (8.22-11.7 mm). By estimate correlation of the previous measurements, the direct and accessible way to expose the posterolateral articular capsule of the elbow joint was through a window in medial 2/3 of the middle segment of anconeus muscle. These trans-anconeus approach is useful. It provides good visualization, facilitates applying the implants, and lessens the risk of radial nerve injury. Awareness of the anatomy is mandatory to avoid injury of LUCL.

Is Male Professional Golfers' 10.94 m Putting Motion a Pendulum Motion? From a Point of View of the Location of the Center of Putter Head Rotation (퍼터헤드 회전중심점 위치 관점에서 본 남자프로골퍼의 10.94 m 퍼팅동작의 진자운동 여부)

  • Park, Young-Hoon;Youm, Chang-Hong;Seo, Kuk-Woong
    • Korean Journal of Applied Biomechanics
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    • v.17 no.2
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    • pp.217-226
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    • 2007
  • Putting score counts about 43 % of the golf score. The dominant idea of the putting motion to amateur golfers as well as to many professional golfers is a pendulum-like motion. If a golfer's putting stroke motion is a pendulum-like motion, the putting motion should be straight-back-and-through, the same backswing, downswing, and follow through length and period, and a swing with a fixed hinge joint. If the putting motions of the human are different from the pendulum motion, there could be confusion in understanding and teaching golf putting. The purpose of this study was to examine the center of rotation(COR) of the putter head to reveal whether professional golfers really putt like a pendulum. Thirteen male professional golfers were recruited for the study. Each golfers executed 10.94 m putts six times on an artificial grass mat. Putter head position data were collected through a 60 Hz three-dimensional motion analysis system and low pass filtered with cut-off frequency of 6 Hz. COR of the putter head was mathematically acquired. Each golfer's last five putting motions were considered. The results show that the COR of the putter head was neither fixed nor located inside of the golfer. The medio-lateral directional component of the COR of the putter head fluctuated in the range of 10 cm during downswing and follow through. The anterior-posterior directional component of the COR of the putter head was fixed from the beginning of the downswing through impact. Just after impact, however, it moved to the target up to 60 cm. The superior-inferior directional component of COR of the putter head moved in a superior direction with the beginning of the downswing and showed peak height just prior to impact. During the follow through, it moved back in an inferior direction. The height-normalized peak value of the COR of the putter head was $1.4{\pm}0.3$ height. Technically speaking, male professional golfers' 10.94 m putting motion is not a pendulum-like motion. The dominating idea of a pendulum-like motion in putting might come from the image of the flawless, smooth motion of a pendulum.

Evaluation of Shear Capacity on PC Girder-PC Beam Joint (PC 큰 보-PC 작은 보 접합부의 전단성능 평가)

  • Moon, Jeong Ho;Oh, Young Hun;Lim, Jae Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.166-174
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    • 2011
  • The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.

Arthroscopic Reduction and Fixation of an Anterior Cruciate Ligament Avulsion Fracture From the Tibial Eminence Using Bioabsorbable Pins - Technical Note - (생흡수성 핀을 이용한 소아 경골 과간부 견열 골절의 관절경적 정복 및 고정 방법 - 수술 술기 -)

  • Lee, Su-Chan;Yang, Il-Soon;Seo, Hee-Soo
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.2
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    • pp.183-187
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    • 2009
  • Purpose: We describe a new and simple technique for arthroscopic fixation of tibial intercondylar eminence avulsion fracture using bioabsorbable pins in skeletally immature patients. Operative Technique: Diagnostic knee arthroscopy is performed using anterolateral and anteromedial portals. Fracture debris and blood clot are debrided to expose the injured site well. The fragment is reduced with the probe and fixed temporarily with a 1.1-mm diameter K-wire that is inserted percutaneously from the anterosuperior aspect of the knee joint. The drill guide is introduced into the joint and the fragment is secured by bioabsorbable, poly-p-dioxanone 1.3-mm pins inserted from different angles. The pins are 40 mm in length. The knee is placed in a long leg cast in extension for 4 weeks to assure that full extension is obtained. Conclusion: Arthroscopic fixation of an tibial intercondylar eminence avulsion fracture using bioabsorbable pins is not a technically demanding, suitable method that ensures fracture healing and restores the stability of the joint.

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