• Title/Summary/Keyword: Fixed Joint

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Longitudinal Kinematical Analysis of Kip to Swallow Motion in Rings (링 운동 차오르며 Swallow 동작 처치 전.후의 기술분석)

  • Back, Jin-Ho;Park, Jong-Hoon;Lee, Yong-Sik
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.173-181
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    • 2006
  • The purpose of this study is grasp the problem of the gymnast, Kim, Dong-Hwa's Kip to Swallow Motion in Rings, and make up for the weak points to help him to perform a better performance. Therefore, two tryouts for $28^{th}$ Athens Olympic Games were filmed using video camera then finalized with Kinematical Analysis using 3D motion analysis program followings are the form of conclusions. 1. In the very first tryout, when he was doing a Swallow Support Scale, his CM position was high and arm slope was deduction because when he was doing Kip, the ascent velocity was low and he tried excessively to pull him on rings due to relying upon angular movement of shoulder joint. 2. When he was doing drop, he let his hip angle bend only little bit and let fall so making shoulder angle wider and maintain the level horizontally occurs strong drop motion when vertical descent is happening. 3. As a result, lowering the direction of a kick makes CM's movement path lower, increase vertical ascent velocity, and it helps to do the Swallow Support motion in short period of time. 4. After a strong drop motion, which is deep and fast, would make rope of ring shake so there is a defect that the body moves to forward area. However, it does not effect in Swallow Support Scale motion. 5. In the second tryout, trunk rotation angle and arm slope was fixed decrease while doing rotary motion. When rotary motion was happening, before the body was going under the rings, maintained his arm slope horizontally so his Swallow Support Scale motion was nearly perfect.

Development of 3 D.O.F parallel robot's simulator for education

  • Yoo, Jae-Myung;Kim, John-Hyeong;Park, Dong-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2290-2295
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    • 2005
  • In this paper, it is developed simulator system of 3 D.O.F parallel robot for educate of expertness. This simulator system is composed of three parts ? 3 D.O.F parallel robot, controller (hardware) and software. First, basic structure of the robot is 3 active rotary actuator that small geared step motor with fixed base. An input-link is connected to this actuator, and this input-link can connect two ball joints. Thus, two couplers can be connected to the input-link as a pair. An end-plate, which is jointed by a ball joint, can be connected to the opposite side of the coupler. A sub-link is produced and installed to the internal spring, and then this sub-link is connected to the upper and bottom side of the coupler in order to prevent a certain bending or deformation of the two couplers. The robot has the maximum diameter of 230 mm, 10 kg of weight (include the table), and maximum height of 300 mm. Hardware for control of the robot is composed of computer, micro controller, pulse generator, and motor driver. The PC used in the controller sends commands to the controller, and transform signals input by the user to the coordinate value of the robot by substituting it into equations of kinematics and inverse kinematics. A controller transfer the coordinate value calculated in the PC to a pulse generator by transforming it into signals. A pulse generator analyzes commands, which include the information received from the micro controller. A motor driver transfer the pulse received from the pulse generator to a step motor, and protects against the over-load of the motor Finally, software is a learning purposed control program, which presents the principle of a robot operation and actual implementation. The benefit of this program is that easy for a novice to use. Developed robot simulator system can be practically applied to understand the principle of parallel mechanism, motors, sensor, and various other parts.

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Combined First Metatarsal and Calcaneal Osteotomy for Fixed Cavovarus Deformity of The Foot (내반 요족 변형에서 시행한 제1중족골 및 종골에 대한 절골술)

  • Chu, In-Tak;Park, Jong-Min;Yoo, Jong-Min;Chung, Jin-Wha
    • Journal of Korean Foot and Ankle Society
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    • v.14 no.2
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    • pp.130-134
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    • 2010
  • Purpose: The aim of this study was to evaluate the result of combined first metatarsal and calcaneal osteotomy for static cavovarus deformity of the foot. Materials and Methods: We performed a dorsal closing wedge $1^{st}$ metatarsal osteotomy and a lateral and upward displacement calcaneal osteotomy for 9 patients, 12 feet (6 male and 3 female). The mean age at the time of operation was 37 years and the mean followup period was 27 months. The causes of deformity were 2 poliomyelitis, 1 cerebral palsy, 1 Charcot-Marie-Tooth disease and 5 idiopathic type. Five lateral ligament reconstructions of the ankle and six percutaneous Achilles tendon lengthenings were added. The surgical results in terms of pain, function and alignment of the foot were evaluated by means of AOFAS ankle-hindfoot score and talo-$1^{st}$ metatarsal, calcaneus-$1^{st}$ metatarsal and calcaneal pitch angles were checked with weight bearing radiographs in lateral projection. Results: Talo-$1^{st}$ metatarsal and calcaneal pitch angles were reduced from the mean preoperative values of $21^{\circ}$ and $25^{\circ}$ to $12^{\circ}$ and $19^{\circ}$, respectively, at last followup. Also, calcaneus-$1^{st}$ metatarsal angle was increased from the mean $114^{\circ}$ to $114^{\circ}$. The mean AOFAS score was improved from 44.5 points preoperatively to 89.2 points at followup. There were 1 metatarso-cueiform joint nonunion, 1 sural nerve injury and 3 remaining symptomatic claw toes. Conclusion: Combined first metatarsal and calcaneal osteotomy appears to be an effective procedure for the treatment of adult static cavovarus foot.

Application of Partnering to Design VE to Public Design-Build Projects (공공부문 일괄입찰사업의 설계VE 파트너링 활용방안)

  • Kim, Hae-Gon;Um, Ik-Jun;Koo, Kyo-Jin;Hyun, Chang-Taek
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.1 s.29
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    • pp.110-118
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    • 2006
  • Current design-build contract is the type of joint venture, but performs by separate party which causes change orders due to the lack of communication between design and construction, so it cannot lead the main object which is the integration of design and construction. Furthermore, the current design-build contract is impossible to reduce the project costs by VE at the design development phase because the design proceeds with the fixed price through bidding. Like these limitless, the analysis results of the case of VE in the design-build projects, several problems that are prevented from active design VE are elicited by the project participants. Meanwhile, Ministry of Construction & Transportation decided to enlarge the VE review system lately. Therefore, in this study, it presented model of design VE partnering of design-build and partnering agreements form to apply design VE and to try to be able to lead the design VE to be more successful in public design-build projects.

Evaluation on Flexural Behavior of Hybrid Beams with Rigid Joint Connecting Steel and Precast Concrete Elements (강재 보-PC 보가 강접합 연결된 하이브리드 보의 휨 거동 평가)

  • Seo, Eun-A;Yang, Keun-Hyeok;Hong, Seung-Hyun
    • Journal of the Korea Concrete Institute
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    • v.28 no.1
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    • pp.13-21
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    • 2016
  • A hybrid precast concrete beam system with a simple rigid connection was proposed to compensate the limitations and shortcomings of the conventional bolt connection associated with the H-beams embedded into concrete beams. Three beam specimens with fixed both ends were tested under one-point top cyclic loading to explore the effectiveness of the developed hybrid beam system in transferring externally applied flexure to a column. The main parameter considered was the length ($L_s$) of H-beam, which was selected to be $0.25L_I$, $0.5L_I$, and $1.0L_I$, where $L_I$ is the distance from the support to the point of inflection. All beam specimens showed a better displacement ductility ratio than the reinforced concrete beams with the same longitudinal reinforcement index, indicating that the cyclic load-deflection curve and ductility were insignificantly affected by $L_s$. The continuous strain distribution along the beam length and the prediction of the ultimate load based on the collapse mechanism ascertained the structural adequacy of the developed rigid connection.

Percutaneous K-wire Fixation of Supracondylar Fracture of Humerus in Children (소아 상완골 과상부 골절의 경피적 K-강선 고정술)

  • Shin, Duk-Seop;Ahn, Jong-Chul;Kim, Se-Dong;Lee, Dong-Woo
    • Journal of Yeungnam Medical Science
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    • v.10 no.2
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    • pp.400-408
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    • 1993
  • During the period from March 1990 to November 1993, 22 children with diplaced supracondylar fracture of humerus were treated by closed reduction and percutaneous K-wire fixation at department of Orthopaedic surgery in Yeungnam University. All fracture were treated with closed reduction under the general anesthesia and percutaneous pinning. After the fracture was internally fixed, intraoperative anteroposterior reontgenograms of each distal humerus were compared. Only anatomical reduction ensured good result, because the main cause of late cubitus varus was medial tilting of distal fragment. We could follow up 10 patients more than one year. By Flynn's criteria, satisfactory result were obtained in 9 of the 10. Unsatisfactory one had a limitation in flexion of elbow joint, but had no problem in cosmetic feature. In short term follow up of 7 patients, 5 patients had a satisfactory result, too. There were no neurovascular complication and hospitalization was shortened to 11.4 days. Closed reduction and percutaneous pinning provided stabillity, vascular safety, simplified management, reduced hospital stay. This is safe and reliable technique for obtaining and maintaining an excellent reduction.

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Full mouth rehabilitation in a patient with loss of vertical dimension caused by severe tooth loss: a case report (광범위한 치질 상실로 인해 수직 고경 감소 환자의 전악 수복 증례)

  • Yun, Ah-Young;Shim, Hye-Won;An, Jin-Hee
    • The Journal of Korean Academy of Prosthodontics
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    • v.52 no.1
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    • pp.42-47
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    • 2014
  • Decrease of occlusal vertical dimension (OVD) due to loss of teeth structure and destruction of the occlusal plane by severely worn dentition may cause cross bite or temporomandibular joint disorder by following change of facial feature or the loss of anterior guidance. Full mouth rehabilitation via an increase of the OVD can be considered to avoid this problem and proper evaluation of patient's OVD is essential. An 80 year old male visited for overall prosthodontic treatment, cross bite due to continuous wear and following decrease of the OVD were observed. We analyzed the existing occlusal relationship using the diagnostic cast, the radiographic evaluation and clinical test, and then proper increase of OVD was selected. The new OVD on diagnostic wax up was placed by the temporary restoration. After 3 months of observation period, final restoration with fixed partial dentures and implant overdenture were made. Throughout the follow-up period of 8 months, the aesthetic and functional improvement can be obtained.

Evaluation of Stress Reduction of Continuous Welded Rail of Sliding Slab Track from Track-Bridge Interaction Analysis (궤도-교량 상호작용 해석에 의한 슬라이딩 슬래브 궤도의 장대레일 응력 저감 효과 분석)

  • Lee, Kyoung Chan;Jang, Seung Yup;Jung, Dong-Ki;Byun, Hyung-Kyoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1179-1189
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    • 2015
  • Continuous welded rail on bridge structure experiences typically a large amount of additional longitudinal axial forces due to longitudinal track-bridge interaction under temperature and traction/braking load effect. In order to reduce the additional axial forces, special type of fastener, such as ZLR and RLR or rail expansion joint should be applied. Sliding slab track system is known to reduce the effect of track-bridge interaction by the application of a sliding layer between slab track and bridge structure. This study presents track-bridge interaction analysis results of the sliding slab track and compares them with conventional fixed slab track on bridges. The result shows that the sliding slab track can significantly reduce the additional axil forces of the continuously welded rail, and the difference is more significant for long and continuous span bridge.

Generalized Combined Power and Rate Adaptations in DS/CDMA Communications over Fading Channels (페이딩 채널에서 직접 대역확산 부호분할 다중접속 통신을 위한 일반화된 혼합 전력/전송률 적응화 기법)

  • Lee, Ye Hoon;Kim, Dong Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.8
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    • pp.680-687
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    • 2013
  • We investigate a generalized combined power and rate adaptation scheme in direct-sequence (DS) code-division multiple-access (CDMA) communications over Nakagami fading channels. The transmission power allocated to user i is proportional to $G^p_i$, where $G_i$ is the channel gain of user i and p is a real number, and the data rate (i.e., spreading gain) is jointly adapted so that a desired QoS is maintained. We analyze the average data rate of the proposed adaptation scheme subject to fixed average and peak transmission power constraints. Our results show that the proposed joint adaptation scheme provides a significant performance improvement over power-only and rate-only adaptation.

A Study on the Preventive Measures against Local Vibrations of Ships' Deck Panels (선체갑판(船體甲板)의 국부진동(局部振動)에 대한 방진설계(防振設計)에 관한 연구(硏究))

  • K.C.,Kim;H.M.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.18 no.1
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    • pp.1-8
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    • 1981
  • To contribute to the preventive measures against local vibrations of ship's deck panels, some investigations into the prediction method of the natural frequency of the vibration of stiffened plates were done. Firstly, an analytical method based on the orthotropic plate analogy and the Rayleigh method using eigenfunctions of the Euler beam was shown, and numerical results of a regularly stiffened plate were compared with experimental results. And then, the method was extended to stiffened plates having one or two irregular stiffeners to obtain an approximate formula showing the relation between the change of the natural frequency and the size of the irregular stiffeners. The latter case was investigated for the purpose of providing a convenient design manual applicable to cure of local resonant vibrations of ships' deck panels by additional reinforcement of one or two stiffeners. In the analytical development the boundary was assumed to be rigidly supported and elastically restrained against rotation. In the experiment, however, only an extreme case i.e. simply supported boundary was investigated. The results of the investigation show that there is a fairly good conformity between the analytical results and the experimental ones in the first case, and that the approximate formula for the second case is confirmed also to be reliable for the design purpose. Considering that actual boundary conditions of deck panels in ship structures lie mostly somewhere between the simple support and the fixed, the authors discussed problems of the joint efficiency at the boundary of deck panels from the viewpoint of the practical application of the formulae.

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