• 제목/요약/키워드: Flexible Joint

검색결과 300건 처리시간 0.024초

바닥 보 구조 기반 조인트 강성 조절법을 이용한 컴플라이언트 메커니즘의 설계 (Ground Beam Structure Based Joint Stiffness Controlling Method for the Design of Compliant Mechanism)

  • 김명진;장강원;김윤영
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.151-156
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    • 2007
  • Topology optimization has been widely used in many research areas due to its ability in providing intial designs for the problems with complex boundary conditions. This also has been useful in compliant mechanisms, but resulting layouts may not be immediately manufacturable because they usually consist of members with varying widths and shapes. Also, there occurs some numerical difficulties such as checkerboards or hinge patterns which result from 1-node connection, and intermediate values which make the manufacturing of the designed structure difficult. Though there are many remedies given to avoid this problems, they cannot be prevented. One may avoid this difficulty by employing uniform ground beams and explicit hinge joints. The proposed method is to connect uniform ground beams with elastic short-beam hinge joints. By choosing the widths of short beams as design variables, dominant deformations can occur mainly by flexible joints having intermediate widths. Unlike the conventional methods used for compliance minimization, intermediate widths must appear in compliant mechanism design problems. Also, the present approach does not encounter the problem of one-point hinges.

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방수재료 및 공법의 내구성 평가를 위한 복합열화분석용 3차원 거동대응 시험결과 (A Study on the Analysis of 3 Dimensional Substrate Behaviour of Complex Environmental Deterioration and the Analysis of Results)

  • 송제영;서현재;최은규;이정훈;김병일;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
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    • pp.189-190
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    • 2018
  • KS standards mostly relate to single component material evaluation, so in cases of underground structure environments, most cannot predict the existing composite forms of deterioration, resulting in the applied waterproofing materials becoming unable to respond to these damaging factors. Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material.

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평행봉 Kenmotsu 동작의 운동학적 분석 (A Kinematical Analysis of the Kenmotsu on the Parallel Bars)

  • 공태웅;김용선;윤창선
    • 한국운동역학회지
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    • 제15권3호
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    • pp.61-70
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    • 2005
  • The purpose of study was to investigate the kinematic variables of Kenmotsu motion in Parallel bars. To this study, by 3 dimensional kinematical analysis of 4 male national gymnasts participants in the 28th Athens Olympic Game in 2004, kinematic data collected using video camera. Coordinate data were smoothed by using a fourth-order Butterworth low pass digital filter with cutoff frequency of 6Hz. The conclusions were as follows. 1. In P2, because the constrained swing movement made the movement of a rising back difficult7, the movements of Reg. were performed at low position after Air phase. 2. In E5 event, for the shake of a stable handstand and applied techniques like a Belle(E-value), a Belle Piked(super E-value), a vertical velocity in E2, a horizontal velocity in E3 and a vertical velocity in E4 were necessary for high velocities. 3. In E4 event, it was appeared that for a flexible body's movement of a vertical up-flight, the large angle of the shoulder joint and the flexion & extension of the hip joint were necessary in Air phase and a long flight time and vertical displacement made Reg. movements stable at the high position.

스피닝을 이용한 롱넥플랜지의 성형공정 개발 (Development of Manufacturing Process for Long-Neck Flange by Spinning)

  • 곽기열;조종래;최진영
    • 한국정밀공학회지
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    • 제32권11호
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    • pp.929-935
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    • 2015
  • The long neck flange is used to connect piping arrangements where the lap joint is applied. Generally, the component can be manufactured by welding, but this method is both time and cost intensive. Embrittlement at the heat affected zones was also considered. A spinning method developed to improve the manufacturing process and solve the problems of welding. The flange area of the long neck flange can be formed by changing the direction of the metal flow, from axial to radial, while maintaining pressure by using an outer mold and a lap roller. A modified process was additionally developed using a round roller rather than the outer mold. In this modification, the round roller can form the shape of all sizes of long neck flange. Using these flexible methodologies, the cost to prepare outer molds and the time to install and remove the molds can be significantly reduced.

Analysis of underground post-tensioned precast concrete box utility tunnel under normal fault displacement

  • Wu, Xiangguo;Nie, Chenhang;Qiu, Faqiang;Zhang, Xuesen;Hong, Li;Lee, Jong-Sub;Kang, Thomas H.K.
    • Computers and Concrete
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    • 제29권2호
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    • pp.69-79
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    • 2022
  • For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

일지역 노인의 관절 건강 상태 (A Study on Health Status of Joints in Elderly People)

  • 은영;김은심;강영실;권인수;오현숙;구미옥
    • 기본간호학회지
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    • 제11권2호
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    • pp.186-194
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    • 2004
  • Purpose: The purpose of this study was to describe the subjective health status of joints, flexibility of joints, muscle strength and state of Joint exercise in elderly people living in the community. Method: The participants were 74 elderly people in a health program of the Gerontological Health Research Center at G University. The data were collected from March to July, 2003. The instrument for the study included items on general characteristics (5 items), subjective health status of joints (10 items), flexibility of Joints and strength of muscle (8 items), and state of joint exercise (7 items). Results: The score for subjective health status of joints was 3.70 (range 1-5). Knee and waist joints were in the worst state. Neck extension and flexion were $17.38{\pm}1.80$ and $.60{\pm}1.08(cm)$ respectively. Trunk extension and flexion were $68.24{\pm}4.47$ and $58.00{\pm}4.91(cm)$ respectively. Flexibility of the Rt./Lt. shoulder joints was $14.63{\pm}12.51/18.82{\pm}13.80(cm)$. Muscle strength of the Rt./Lt. leg was $30.47{\pm}19.68/29.67{\pm}21.22$ (sec.). Shoulder joints were more flexible for men and people in their sixties compared to women and people in their seventies. Hand grip was stronger for men compared to women. The score for state of joint exercise was 2.83(range 1-4). The state of handgrip correlated with the state of joint exercise [r=.423 (Rt.)/r=.273(Lt.)]. Conclusion: To prevent falls and disorders in neuromuscular function, it is important to develop systemic joint exercise programs for elderly people.

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CNT 기반의 직물센서 구현 방법에 따른 관절동작 센싱 효율 평가 (Evaluating Joint Motion Sensing Efficiency According to the Implementation Method of CNT-Based Fabric Sensors)

  • 조현승;양진희;이주현
    • 감성과학
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    • 제24권4호
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    • pp.129-138
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    • 2021
  • 본 연구의 목적은 본 연구에서는 탄소나노튜브 기반의 신축성 직물 센서의 모양과 의복 상 부착 위치가 아동의 사지 관절 동작 센싱 성능에 미치는 영향을 분석하고, 이를 통해 아동의 사지 동작 센싱에 적합한 직물 동작 센서의 요건을 규명하고자 하였다. 실험 대상 아동에게 2종의 센서 모양과 2개의 센서 부착 위치에 따라 조작된 실험복을 착의시킨 후 60 deg/sec의 속도로, 팔과 다리의 굽힘-폄 동작(60°, 90°의 동작 각도별로 10회씩 3회 반복 동작, 총 60회 동작)에 의한 직물 센서의 신장과 수축에 따른 전압의 변화량을 측정하였으며, 가속도 센서를 함께 부착하여, 센싱 결과의 일치도를 분석함으로써 신뢰도를 검증하였다. 실험 결과 아동의 팔과 다리 동작을 가장 효율적으로 측정할 수 있는 직물 센서의 구성 요건은 장방형 모양 센서 및 관절로부터 4cm 아래 부위에 부착된 센서로 나타났다. 본 연구에서는 아동의 사지 동작 측정에 적합한 직물 센서를 개발하고 관절동작 센싱에 적합한 센서의 모양과 의복 상 부착 위치에 대한 조건을 분석하였으며, 의복에 통합된 유연한 직물 센서를 활용하여 인체 부위별 동작 센싱이 가능하다는 것을 규명하였다.

Modeling and SINR Analysis of Dual Connectivity in Downlink Heterogeneous Cellular Networks

  • Wang, Xianling;Xiao, Min;Zhang, Hongyi;Song, Sida
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권11호
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    • pp.5301-5323
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    • 2017
  • Small cell deployment offers a low-cost solution for the boosted traffic demand in heterogeneous cellular networks (HCNs). Besides improved spatial spectrum efficiency and energy efficiency, future HCNs are also featured with the trend of network architecture convergence and feasibility for flexible mobile applications. To achieve these goals, dual connectivity (DC) is playing a more and more important role to support control/user-plane splitting, which enables maintaining fixed control channel connections for reliability. In this paper, we develop a tractable framework for the downlink SINR analysis of DC assisted HCN. Based on stochastic geometry model, the data-control joint coverage probabilities under multi-frequency and single-frequency tiering are derived, which involve quick integrals and admit simple closed-forms in special cases. Monte Carlo simulations confirm the accuracy of the expressions. It is observed that the increase in mobility robustness of DC is at the price of control channel SINR degradation. This degradation severely worsens the joint coverage performance under single-frequency tiering, proving multi-frequency tiering a more feasible networking scheme to utilize the advantage of DC effectively. Moreover, the joint coverage probability can be maximized by adjusting the density ratio of small cell and macro cell eNBs under multi-frequency tiering, though changing cell association bias has little impact on the level of the maximal coverage performance.

저작권법의 시각에서 본 연극연출의 창작성과 법적 지위에 관한 연구 (The Study on the Creativity and Legal Status of Directing from Copyright Law Point of View)

  • 정영미
    • 한국연극학
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    • 제40호
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    • pp.401-450
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    • 2010
  • This thesis purposes to suggest that creative stage directors have copyright ownership and we make them create high-quality of theatre direction. Stage directors are sincere creator of the theatre stage today. We have little judicial precedents about stage directors, no artistic examination related directing. Stage directors are performers who have neighboring rights, there is a problem that they won't have the exclusive right of making derivative works in this country. Others will make creation (such as cinemas, animations, novels) based on stage expression without permission, because stage directors don't have exclusive right of making derivative works. Copyright law can't protect the concept of stage directors and building blocks of them which are drama text, actors and theatre space, because copyright law don't protect idea according to idea/expression dichotomy. The expression of stage direction is belong to five fundamentals which are composition, picturization, movement, rhythm, pantomimic dramatization that are come from Dean & Carra's work. Directors' work is to make theatrical works based on literary works. Therefore, theatrical works are derivative works which based on drama texts. Also, theatrical works are able to be joint works. In the case of that stage directors write drama text and create expression on the stage, they have to own authorship of both works. Merger doctrine should not apply theatre directors' works strictly like any other functional works because stage directors usually create noble expression which have been not before. We need shift of the definition of theatrical works which are derivative works or joint works to protect theatre directors' creativity. Hereafter, the special legal section for dramatic(theatrical) works including the flexible legal definition for performing arts should be established, and 'contract form' for stage directors should be made. Acting edition(literary works) should be published to grant creative directors compensation. I emphasize to grant ownership of copyright to creative stage directors, to encourage directors' works. Therefore, copyright law will be the support for development of cultural arts institutionally.

Numerical analysis of segmental tunnel linings - Use of the beam-spring and solid-interface methods

  • Rashiddel, Alireza;Hajihassani, Mohsen;Kharghani, Mehdi;Valizadeh, Hadi;Rahmannejad, Reza;Dias, Daniel
    • Geomechanics and Engineering
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    • 제29권4호
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    • pp.471-486
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    • 2022
  • The effect of segmental joints is one of main importance for the segmental lining design when tunnels are excavated by a mechanized process. In this paper, segmental tunnel linings are analyzed by two numerical methods, namely the Beam-Spring Method (BSM) and the Solid-Interface Method (SIM). For this purpose, the Tehran Subway Line 6 Tunnel is considered to be the reference case. Comprehensive 2D numerical simulations are performed considering the soil's calibrated plastic hardening model (PH). Also, an advanced 3D numerical model was used to obtain the stress relaxation value. The SIM numerical model is conducted to calculate the average rotational stiffness of the longitudinal joints considering the joints bending moment distribution and joints openings. Then, based on the BSM, a sensitivity analysis was performed to investigate the influence of the ground rigidity, depth to diameter ratios, slippage between the segment and ground, segment thickness, number of segments and pattern of joints. The findings indicate that when the longitudinal joints are flexible, the soil-segment interaction effect is significant. The joint rotational stiffness effect becomes remarkable with increasing the segment thickness, segment number, and tunnel depth. The pattern of longitudinal joints, in addition to the joint stiffness ratio and number of segments, also depends on the placement of longitudinal joints of the key segment in the tunnel crown (similar to patterns B and B').