• 제목/요약/키워드: JOINT

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관절 역학과 협응이 최대 수직 점프의 개인내 수행차에 미치는 영향 (Effect of Joint Kinetics and Coordination on the Within-Individual Differences in Maximum Vertical Jump)

  • 김용운;서정석;한동욱
    • 한국운동역학회지
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    • 제22권3호
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    • pp.305-314
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    • 2012
  • The purpose of this study was to investigate the effects of joint kinetics and coordination on within-individual differences in maximum vertical jump. 10 male subjects aged 20 to 30 performed six trials in maximum vertical jump and with based on jump height the good(GP) and bad(BP) performances for each subject were compared on joint kinetics of lower extremity and coordination parameters such as joint reverse and relative phase. The results showed that maximum moment, power, and work done of hip joint and maximum moment of ankle joint in GP were significantly higher than that in the BP but no significant differences for the knee joint. We could observe a significant difference in joint reverse timing between both conditions. And also the relative phase on ankle-knee and ankle-hip in GP were significantly lower than that in the BP, which means that in GP joint movements were more in-phase synchronized mode. In conclusion, mechanical outputs of hip and ankle joints had an effect on within-individual differences in vertical jump and the inter-joint coordination and coordination including sequence and timing of joint motion also might be high influential factors on the performances within individual.

루이스 칸 건축에 나타나는 반접합(反接合)의 의미에 관한 연구 (A Study on the Meaning of Dis-joint in the Architecture of Louis Kahn)

  • 김낙중;정태용
    • 한국실내디자인학회논문집
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    • 제18권3호
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    • pp.39-46
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    • 2009
  • The purpose of this study is to analyze the meaning of 'dis-joint' in the works of Louis I. Kahn. Kahn tried to realize his main architectural thoughts of 'what it wants to be' and 'how it was done' through his whole life. The concept of 'dis-joint' had been developed to visualize his architectural thoughts. Kahn used' dis-joint' to show and emphasize the structural system for the raison d'etre of building. Kahn's 'dis-joint' can be categorized as 'spacing', 'butt', 'slit' and 'protrusion'. Kahn used this kind of unusual way of joint beyond simple exposure to stress the existence of element, part and building itself. Through variable combination usage of 'dis-joint', Kahn can realize his architectural thoughts into building in a concrete way. The efficiency and function of joint is not the main issue in his works. 'Dis-joint' was the concrete tool to show the tectonic of architecture and construction process to enhance its presence. Therefore 'dis-joint' of Kahn's architecture is not a joint only to combine building parts but a concrete mean to realize his thoughts in a corporeal way. These facts insinuate that Kahn's architectural philosophy is based on the thoughts of tectonic and its realization.

슬관절의 운동학적 분석 (Arthrokinetic Analysis of Knee Joint)

  • 김재헌
    • PNF and Movement
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    • 제6권1호
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    • pp.53-60
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    • 2008
  • Purpose : To describes the important aspects of knee joint movement and function used when applying PNF technique to the lower limb. Method : The knee was a very important roles in the lower limb movement and ambulation. This study summarizes the physiologic movement of knee to the PNF lower extremity patterns. Result : The tibiofemoral joint is usually described as a modified hinge joint with flexion-extension and axial rotation by two degrees of freedom movement. These arthrokinematics are a result of the geometry of the joints and the tension produced in the ligamentous structures. The patellofemoral joint is a sellar joint between the patella and the femur. Stability of the patellofemoral joint is dependent on the passive and dynamic restraints around the knee. In a normal knee the ligaments are inelastic and maintain a constant length as the knee flexes and extends, helping to control rolling, gliding and translation of the joint motions. Conclusions : It is important to remember that small alterations in joint alignment can result in significant alterations in patellofemoral joint stresses and that changes in the mechanics of the patellofemoral joint can also result in changes in the tibiofemoral compartments. Successful treatment requires the physical therapist to understand and apply these arthrokinematic concepts. When applied to PNF low extremity patterns, understanding of these mechanical concepts can maximize patient function while minimizing the risk for further symptoms or injury.

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The Effect of Joint Mobilization with PNF Stretch Exercise on Ankle Joint Range of Motion, Plantar Pressure, and Balance in Patients with Stroke

  • Ryu, Byeong Ho
    • 국제물리치료학회지
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    • 제9권4호
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    • pp.1642-1650
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    • 2018
  • The purpose of this study was to identify the effect of proprioceptive neuromuscular facilitation (PNF) stretching exercise and joint mobilization on ankle joint range of motion (ROM), plantar pressure, and balance in subjects with stroke. Thirty patients (n=30) were organized into three groups, each of which received different treatments: PNF stretching (n=10), joint mobilization (n=10), and joint mobilization and PNF stretching combined (n=10). Each group received three exercise sessions per week for four weeks. The ankle ROM was measured using a goniometer, and plantar pressure and balance ability were measured using BioResque static posturography. In comparison within each group, the joint mobilization group and the joint mobilization with PNF stretching group showed significant improvements in ankle ROM, plantar pressure, and balance ability (p<.05). In comparison between the groups, a statistically significant difference was found in SECS change between the PNF stretching group, joint mobilization group and the joint mobilization with PNF stretching group. This study found demonstrates that the joint mobilization and joint mobilization with the PNF stretching methods were effective in improving ankle ROM, plantar pressure, and balance ability in stroke patients.

Seismic performance of exterior R/C beam-column joint under varying axial force

  • Hu, Yanbing;Maeda, Masaki;Suzuki, Yusuke;Jin, Kiwoong
    • Structural Engineering and Mechanics
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    • 제78권5호
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    • pp.623-635
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    • 2021
  • Previous studies have suggested the maximum experimental story shear force of beam-column joint frame does not reach its theoretical value due to beam-column joint failure when the column-to-beam moment capacity ratio was close to 1.0. It was also pointed out that under a certain amount of axial force, an axial collapse and a sudden decrease of lateral load-carrying capacity may occur at the joint. Although increasing joint transverse reinforcement could improve the lateral load-carrying capacity and axial load-carrying capacity of beam-column joint frame, the conditions considering varying axial force were still not well investigated. For this purpose, 7 full-scale specimens with no-axial force and 14 half-scale specimens with varying axial force are designed and subjected to static loading tests. Comparing the experimental results of the two types of specimens, it has indicated that introducing the varying axial force leads to a reduction of the required joint transverse reinforcement ratio which can avoid the beam-column joint failure. For specimens with varying axial force, to prevent beam-column joint failure and axial collapse, the lower limit of joint transverse reinforcement ratio is acquired when given a column-to-beam moment capacity ratio.

자동차용 강판의 접착특성 - 접착부위 접합 강도와 영향인자 - (Characteristics of Adhesive bonded Joints of Steels for Automobile(I))

  • 윤병현;권영각
    • Journal of Welding and Joining
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    • 제13권2호
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    • pp.106-114
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    • 1995
  • The characteristics of adhesive bonded joint of steels for automobile were investigated. Shear and tear strength were tested and analyzed for the joints of cold rolled steel sheets bonded with three kinds of epoxy and urethane based adhesive. The results showed that the tensile shear strength and the tear strength of adhesive joint were affected by the shape of adhesive joint such as the length and width of adhesive joint. The thickness of adhesive layer was very important factor affecting the bonding strength. The shear strength increased with decrease of the thickness of adhesive layer, while the tear strength decreased as the thickness of adhesive layer decreased. In comparison with the strength of spot welded joint, the shear strength of adhesive Joint was higher than that of spot welded joint, but the tear strength of adhesive Joint was lower than that of spot welded joint.

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유리 중족-족지관절 이식술을 이용한 주관절 전치환술 (Biologic Arthroplasty of Elbow with Free Metatarso-Phalangeal Joint Transplantation)

  • 정덕환
    • Archives of Reconstructive Microsurgery
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    • 제9권2호
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    • pp.154-157
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    • 2000
  • Author report a case of double metatarso-phalangeal joint transplantation to the elbow joint in the 31 years old female patient who have large bone defect associated with skin and soft tissue defect. The donor joints were second and third metatarso-phalangeal joint as double joint transfer fashion to enhance stability of graft. The graft based on dorsalis pedis vessel to anastomosed with radial artery of recipient site. The result is unsatisfactory because of long lasting lateral instability of reconstructed elbow joint in spite of 40 degree flexion motion and fair axial stability. We can conclude that joints from foot can not be an effective donor for biologic joint arthroplasty of elbow joint even though double metatarso-phalangeal joint were harvested.

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최적 제어기법을 이용한 다관절 유연 로보트팔의 역동역학 해석 (Inverse Dynamic Analysis of A Flexible Robot Arm with Multiple Joints by Using the Optimal Control Method)

  • Kim, C.B.;Lee, S.H.
    • 한국정밀공학회지
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    • 제10권3호
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    • pp.133-140
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    • 1993
  • In this paper, we prpose a method for tracking optimally a spatial trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint euqations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation result of a flexible planar manipulator is presented.

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차체접합과 관련한 접합 강도 평가 (Strength Evaluation of Adhesive Bonded Joint for Car Body)

  • 이강용;김종성;공병석;우형표
    • 한국자동차공학회논문집
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    • 제6권1호
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    • pp.143-150
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    • 1998
  • The evaluation of joint fatigue strength of light weight materials for electrical vehicle body has been performed through single lap joint tests with the design parameters such as joint style, adherend, bonding overlap length and bonding thickness. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the stress ratio zero value. It is experimentally observed that fatigue strength of joint increases for the increase of overlap length. The combinations of Al-Al and Al-FRP adherends show that fatigue strength of joint is hardly changed for the increase of bonding thickness, but FRP-FRP adherend specimen shows that fatigue strength of joint increases after decreases for the increase of bonding thickness. Al-Al adherend specimen has much higher fatigue length than Al-FRP and FRP-FRP adherend specimens. Riveting at adgesive bonded joint gives little effect on fatigue strength.

축약 행렬법을 적용한 차체 결합부 해석 (Application of Condensed Joint Matrix Method to the Joint Structure of Vehicle Body)

  • 서종환;서명원;양원호
    • 한국자동차공학회논문집
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    • 제6권4호
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    • pp.9-16
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    • 1998
  • The joint characteristics are necessary to be determined in the early stage of the vehicle body design. Researches on identification of joints in a vehicle body have been performed until the recent year. In this study, the joint characteristics of vehicle struct- ure were expressed as condensed forms from the full joint stiffness and mass matrix. The condensed joint stiffness and mass matrix were applied to typical T-type and Edge-type joints, and the usefulness was confirmed. In addition, those were applied to center pillar and full vehicle body to validate the practical application.

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