• Title/Summary/Keyword: finger joint

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Effects of Finger-joint on Bending Performance of Square Timbers Produced from Domestic Small Diameter Larch Logs (핑거조인트가 국산 낙엽송 소경각재의 휨성능에 미치는 영향)

  • Kim, Yun-Hui;Jang, Sang-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.3
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    • pp.301-308
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    • 2014
  • Despite Korea forest take 63.7% of the nation's territory, productivity of domestic structural lumber is low. Studies of domestic small lumbers need to be improved domestic structural timber productivity. In this study, small diameter lumber and finger joint small diameter lumber took bending test to calculate MOE and MOR. MOE of small diameter lumber was $9.3kN/mm^2$ and MOE of finger joint small diameter lumber was $15.4kN/mm^2$. Allowable standard bending stress of small diameter lumber and finger joint small diameter lumber was calculated according to ASTM D 2915. Standard allowable bending stress of small diameter lumber was $12N/mm^2$ and standard allowable bending stress of finger joint small diameter lumber was $11N/mm^2$. Standard allowable bending stress of finger joint small diameter lumber should be considered to design structural beam members.

An Experiment of Structural Performance of Expansion Joint with Rotation Finger (가변형 핑거 조인트를 가지는 신축이음장치의 구조 성능 실험)

  • Yoo, Sung won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.170-175
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    • 2018
  • For the seismic performance, it is necessary to prevent the destruction of the expansion joint device due to the appropriate deformation of the expansion joint device due to the seismic force. Recently, the hinge is installed on the fingering of the expansion joint device in Korea, New products are being developed. In this paper, we have experimentally evaluated the real scale resistance of the expansion joints with rotational finger joints against load at right angle to the bridge axis. Experimental results show that the maximum horizontal displacement is about 21.1mm for conventional stretch joints and 51.00mm for seismic stretch joints. It is presumed that the existing expansion joint test specimen is resistant to the load in a direction perpendicular to the throat axis, and then the bending and shear deformation of the finger are excessively generated and the fracture phenomenon is likely to occur. On the other hand, in the case of the seismic expansion joint, the deformation of the load due to the load is absorbed by the hinge of the finger with respect to the load in the direction perpendicular to the throat, so that only horizontal deformation in the direction of load action.

The Lateral Middle Phalangeal Finger Flap for Pulp and Palmar Defects of the Finger (수지 첨부 및 수장부 연부 조직 결손에서 시행한 외측 중위 수지 피판술)

  • Chung, Duke-Whan;Lee, Jae-Hoon
    • Archives of Reconstructive Microsurgery
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    • v.15 no.1
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    • pp.33-37
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    • 2006
  • Purpose: The aim of this study was to evaluate the efficacy of lateral middle phalangeal finger flap for pulp and palmar defect of the finger. Materials and methods: We performed the lateral middle phalangeal finger flap in thumb pulp defect 4 cases and the palmar defect of other finger 3 cases. Mean age was 38(25-53) years old and there were male 6 cases and female 1 case. Sensate flap was performed in 4 cases of thumb pulp defects. Mean follow-up period was 14(7-22) months. Results: All flaps were survived. Mean static two-pint discrimination of sensate flap 4 cases was 8(6-10) mm. The sensation of donor finger tip was normal in all cases. Limitation of range of motion of the donor fingers was absent. Patients complained of transient cold intolerance 1 month after surgery but didn't complain of that in all cases at last follow-up. Conclusions: The advantages of the lateral middle phalangeal finger flap are the preservation of the ipsilateral palmar digital nerve, good sensory reconstruction of the fingertip, well maintained donor finger mobility with minimal exposure of the extensor tendon, cosmetically good appearances of donor finger, and easy raising as a large flap. So we suggest that this flap is versatile for reconstructing of relatively large pulp defect of the thumb and the palmar defects involving the joint of finger.

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Design of a Humanoid Robot-hand with MEC-Joint (멕조인트를 이용한 다관절 로봇핸드 설계)

  • Lee, Sang-Mun;Lee, Kyoung-Don;Min, Heung-Ki;Noh, Tae-Sung;Kim, Sung-Tae
    • The Journal of Korea Robotics Society
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    • v.7 no.1
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    • pp.1-8
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    • 2012
  • A humanoid robot hand with one thumb and two fingers has been developed. Each finger has the specially designed compact joints, called "MEC Joint", which convert the rotation of a motor to the swing motion of a pendulum. The robot hand with the MEC Joints is compact and relatively light but strong enough to grasp objects in the same manner as human being does in daily activities. In this paper the kinematic model and the torque characteristics of the MEC Joint are presented and compared with the results of the dynamic simulation and the dynamometer test. The dynamic behavior of the thumb and two fingers with MEC Joints are also presented by computer simulation.

Effects of Finger Joint and Strength of Lamination on the Estimation of Strength Properties of Glulam (집성재의 강도적 성질 예측에 대한 핑거 조인트와 라미나의 강도의 영향)

  • Kim, Gwang-Chul;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.1
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    • pp.8-17
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    • 2000
  • Structural glued laminated timbers were manufactured from Japanese larch(Larix leptolepis) lumber. The effect of various factors, such as finger joint, strength of lamination, on the strength properties of glulam was investigated. When only MOE of lamina was used as input variable for the estimation of strength properties of glulam, the deviations between actual and simulated results were increased with the number of lamination, because the effects of variance of lamina properties on the strength estimation of glulam were cumulated with the number of lamination. Therefore, to estimate the MOR of glulam more careful approach was needed. Besides, both MOE and MOR of lamination were used as input variable to compare the effect of input variable. In the case of finger jointed lamination was located in tension zone, MOE of glulam was some effected, because of the variation of MOE of lamination and the deficiency of information for knot. In the case of finger jointed lamination wasn't located in tension zone, more exact estimation was possible than the case of finger jointed lamination was located in tension zone. From the results, it was concluded that more exact estimation of strength properties of glulam could be obtained by considering effects of both finger joint and knot.

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Reconstruction of Soft Tissue Defects in the Finger using Arterialized Venous Free Flaps (유리 동맥화 정맥 피판을 이용한 수지 연부조직 결손의 재건)

  • Lee, Young-Keun;Woo, Sang-Hyun;Lee, Jun-Mo;Ahn, Hee-Chan;Cheon, Ho-Jun
    • Archives of Reconstructive Microsurgery
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    • v.19 no.1
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    • pp.21-28
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    • 2010
  • Purpose: To report the clinical results of the use of arterialized venous free flaps in reconstruction in soft tissue defects of the finger and to extend indications for the use of such flaps based on the clinical experiences of the authors. Materials and Methods: Eighteen patients who underwent arterialized venous free flaps for finger reconstruction, between May 2007 and July 2009 were reviewed retrospectively. The mean flap size was 4.7${\times}3.2$ cm. The donor site was the ipsilateral volar aspect of the distal forearm in all cases. There were 8 cases of venous skin flaps, 5 cases of neurocutaneous flaps, 4 cases of tendocutaneous flaps, 1 case of innervated tendocutaneous flap. The vascuality of recipient beds was good except in 4 cases (partial devascuality in 2, more than 50% avascuality (bone cement) in 2). Results: All flaps were survived. The mean number of included veins was 2.27 per flap. Mean static two-point discrimination was 10.5 mm in neurocutaneous flaps. In 3 of 5 cases where tendocutaneous flaps were used, active ROM at the PIP joint was 60 degrees, 30 degrees at the DIP joint and 40 degrees at the IP joint of thumb. There were no specific complications except partial necrosis in 3 cases. Conclusions: An arterialized venous free flap is a useful procedure for single-stage reconstruction in soft tissue or combined defect of the finger; we consider that this technique could be applied to fingers despite avascular recipient beds if the periphery of recipient bed vascularity is good.

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Vision and Depth Information based Real-time Hand Interface Method Using Finger Joint Estimation (손가락 마디 추정을 이용한 비전 및 깊이 정보 기반 손 인터페이스 방법)

  • Park, Kiseo;Lee, Daeho;Park, Youngtae
    • Journal of Digital Convergence
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    • v.11 no.7
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    • pp.157-163
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    • 2013
  • In this paper, we propose a vision and depth information based real-time hand gesture interface method using finger joint estimation. For this, the areas of left and right hands are segmented after mapping of the visual image and depth information image, and labeling and boundary noise removal is performed. Then, the centroid point and rotation angle of each hand area are calculated. Afterwards, a circle is expanded at following pattern from a centroid point of the hand to detect joint points and end points of the finger by obtaining the midway points of the hand boundary crossing and the hand model is recognized. Experimental results that our method enabled fingertip distinction and recognized various hand gestures fast and accurately. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 90% and the performance indicated over 25 fps. The proposed method can be used as a without contacts input interface in HCI control, education, and game applications.

Stener-Like Lesions in the Metacarpophalangeal Joint of the Fingers (다른 수지의 중수수지 관절에서의 Stener 유사 병변)

  • Lee, Sanglim;Jung, Eui Yub;Lee, Jihae;Jeon, Suk Ha
    • Journal of the Korean Orthopaedic Association
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    • v.53 no.6
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    • pp.547-551
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    • 2018
  • Three Stener-like lesions of the metacarpophalangeal joint of the fingers and a rupture of the first dorsal interosseous muscle mimicking the lesion in the index finger were observed. Two cases in the little fingers had a true Stener's lesion. In one case in the index finger, the ruptured ligament was retracted and located under the intact sagittal band, which was also observed by preoperative magnetic resonance imaging (MRI). Rupture of the first dorsal interosseous muscle was misdiagnosed preoperatively as a Stener's lesion in the index finger by ultrasonography. MRI should be an essential differential diagnostic exam for collateral ligament ruptures of the metacarpophalangeal joint of the fingers.

The Static Behavior of Bridge Expansion Joints Due to the Wheel Load (윤하중 재하에 의한 교량 신축이음의 정적거동)

  • Kim, Youngjin;Kwak, Imjong;Cho, Changbaek;Yoon, Hyejin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3A
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    • pp.357-366
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    • 2008
  • This study addresses the analysis of the behavioral characteristics of bridge expansion joints under wheel loading through wheel load test and the proposal of relevant wheel load specifications for expansion joints. To that goal, specimens of rail and finger expansion joints that are widely used in Korea were fabricated and subjected to static wheel load test using a real tire wheel. The wheel load distribution factor in the rail and finger expansion joints in contact with the wheel load was evaluated. The evaluation revealed that the portion of load sustained by the central rail of rail expansion joint was decreasing with larger wheel load, and that the portion of load sustained by the finger expansion joint was practically insensitive to the increase of the contact area and remained nearly constant. Since the wheel load characteristics showed large difference compared to former design specifications, it appears necessary to prepare rational specifications relative to the distribution of the wheel load contact pressure for the design of expansion joints.

Resting Hand and Wrist Posture Evaluation (휴식 상태의 손과 손목 자세 평가)

  • Lee, Kyung-Sun;Jung, Myung-Chul
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.5
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    • pp.727-734
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    • 2010
  • The objective of this study was to evaluate the resting postures of the fingers and wrist based on the biomechanical model in term of hand posture (neutral, pronation, and supination) and gender (male and female). The finger and wrist joint angles were measured with VICON motion system. The EMG system was used to examine the muscle activity in the resting condition. The participants consisted of twenty male and twenty female students. The angles of the fingers and wrist were analyzed by means of the coordinate system associated with the International Society of Biomechanics. Hand posture was significant for all the joints. The finger and wrist joint flexed in supination more than in neutral and pronation. The hand posture and gender were not significant for the results of muscle activity, but it had larger muscle activities in supination more than in neutral and pronation.