• Title/Summary/Keyword: Elastic joint

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Thermal Characteristic of the Tubular Single tap Adhesively Bonded Joint bonded with filler containing epoxy adhesive (충전재가 함유된 단일겹치기 접착 조인트의 열적 특성에 관한 연구)

  • Kim, Jin-Kook;Lee, Dai-Gil
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.370-376
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    • 2001
  • When an adhesive joint is exposed to high environmental temperature, the tensile load capability of the adhesive joint decreases because the elastic modulus and failure strength of structural adhesive decrease. The thermo-mechanical properties of structural adhesive can be improved by addition of fillers to the adhesive. In this paper, the elastic modulus and failure strength of adhesives as well as the tensile load capability of tubular single lap adhesive joints were experimentally and theoretically investigated with respect to the volume fraction of filler (alumina) and the environmental temperature. Also the tensile modulus of the fille containing epoxy adhesive was predicted using a new equation which considers filler shape, filler content and environmental temperature. The tensile load capability of the adhesive joint was predicted by using the effective strain obtained from the finite element analysis and a new failure model, from which the relation between the bonding length and the crack length was developed with respect to the volume fraction of filler.

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Elasto-plastic Joint Finite Element Analysis of Root-pile Using the Direct Shear Test Model (직접전단시험모델에 의한 뿌리말뚝의 탄소성조인트 유한요소해석)

  • Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.4
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    • pp.19-30
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    • 2002
  • The stability of slope using root-pile like to the reinforcements is affected by the interaction behavior mechanism of soil-reinforcements. Through the studying on the interaction in joint of its, therefore, the control roles can be find out in installed slope. In study, the stress level ratio based on the insert angle of installed reinforcements in soil used to numerical analysis, which was results from the duty direct shear test in Lab. The maximum shear strain variation on the reinforcements was observed at insert angle, which was approximately similar to the calculated angle based on the equation proposed by the Jewell. The elasto-plastic joint model on the contact area of soil-reinforcements was presumed, the reinforced soil assumed non-linear elastic model and the reinforcements supposed elastic model, respectively. The finite element analysis of assumed models was performed. The shear strain variation of non-reinforced state obtained by the FEM analysis including elasto-plastic joint elements were shown the rationality of general limit equilibrium analysis for the slope failure mode on driving zone and resistance zone, which based on the stress level step according to failure ratio. Through the variation of shear strain for the variation of inserting angle of reinforcements, the different mechanism on the bending and the shear resistance of reinforcements was shown fair possibility.

Joint Identification of Multiple Genetic Variants of Obesity in a Korean Genome-wide Association Study

  • Oh, So-Hee;Cho, Seo-Ae;Park, Tae-Sung
    • Genomics & Informatics
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    • v.8 no.3
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    • pp.142-149
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    • 2010
  • In recent years, genome-wide association (GWA) studies have successfully led to many discoveries of genetic variants affecting common complex traits, including height, blood pressure, and diabetes. Although GWA studies have made much progress in finding single nucleotide polymorphisms (SNPs) associated with many complex traits, such SNPs have been shown to explain only a very small proportion of the underlying genetic variance of complex traits. This is partly due to that fact that most current GWA studies have relied on single-marker approaches that identify single genetic factors individually and have limitations in considering the joint effects of multiple genetic factors on complex traits. Joint identification of multiple genetic factors would be more powerful and provide a better prediction of complex traits, since it utilizes combined information across variants. Recently, a new statistical method for joint identification of genetic variants for common complex traits via the elastic-net regularization method was proposed. In this study, we applied this joint identification approach to a large-scale GWA dataset (i.e., 8842 samples and 327,872 SNPs) in order to identify genetic variants of obesity for the Korean population. In addition, in order to test for the biological significance of the jointly identified SNPs, gene ontology and pathway enrichment analyses were further conducted.

Changes in Medial Knee Displacement and Lower Extremity Kinematics in Subjects with Dynamic Knee Valgus Following Application of Non-elastic Tape to the Hip Joint while Performing an Overhead Squat (오버헤드 스쿼트를 실시하는 동안 비탄력 테이핑의 엉덩관절 적용에 따른 동적 무릎 밖굽이가 있는 대상자의 무릎 내측 전위와 하지의 운동형상학의 변화)

  • Go-eun Choi;Jong-chul Jung;Dong-yun Bae;Won-young Park;Da-in An;Young-il Shin;Sung-hwa Go;Jun-seok Kim;Soo-Yong Kim
    • PNF and Movement
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    • v.21 no.3
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    • pp.337-344
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    • 2023
  • Purpose: The purpose of this study was to evaluate changes in the lower extremity kinematics of subjects with dynamic knee valgus after we applied non-elastic tape while they performed overhead squat. Methods: Twenty-five subjects (12 females, 13 males) with dynamic knee valgus participated in this study. Hip and knee joint kinematics and medial knee displacement were measured during overhead squat with and without hip correction taping. Results: Hip joint internal rotation, knee valgus, and medial knee displacement were significantly lower during overhead squat with hip correction taping than without hip correction taping, but there was no significant difference in hip joint flexion and abduction. Conclusion: Hip joint correction using non-elastic taping is recommended to subjects with dynamic knee valgus to improve their lower extremity movement and alignment during overhead squat.

An Assessment on the Ultimate Strength of Welding Joint by the Effect of External Force (外力의 效果를 고려한 熔接部의 最終强度에 대한 評價)

  • Bang, Han-Seo;Cha, Yong-Hun;O, U-Seok
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.20-29
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    • 1995
  • When structures are constructed by welding, structural elements are always accompained by welding residual stress and deformation. Therefore, when the rigidity and strength of the welded structures is considered, it is very important to have sufficient information about the effect of initial deflection and welding residual stress on them. In this paper, the square plates with welding residual stress under compression are dealt with; First, heat conduction and thermal elastic-plastic problems are analyzed by finite element method using 4-node isoparametric elements for assessment on the ultimate strength of welding joint. Later, the ultimate strength of welding joint is assessed by examining the effect of changed type of loading. The specimens are 500{\times}$500mm(a/b=1) and 750{\times}$500mm(a/b=1.5) rectangular plates of whichthicknesses is 9.0mm and simply supported plates getting axiul load in each direction.

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Lateral Vibration of Beams with a Bonded Lap Joint and Partial Layered Dampers (겹침이음부 및 국부적 층댐퍼를 갖는 보의 횡진동 특성)

  • 박정일;최낙삼
    • Journal of KSNVE
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    • v.9 no.1
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    • pp.174-183
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    • 1999
  • An analytical model for the lateral vibration of beams with a bonded lap joint and partial layered dampers has been proposed in this paper. Both shear and normal forces acting along the interface between the elastic and viscoelastic layers were considered in the vibration analysis. Analytical results were compared with those obtained by a finite element method. Effects of the size and location of layers in partial dampers on system loss factor($\eta_s$) and resonant frequency($\omega_r$) were studied. which showed that partial dampers adhered to the site exhibiting the maximum amplitude of vibration were most influential in the increase of $\eta_s$ and the decrease of $\omega_r$. Specific system loss factor( $\eta_s$ divided by total mass of system) was also evaluated in the analysis.

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Development of Flexible and Lightweight Robotic Hand with Tensegrity-Based Joint Structure for Functional Prosthesis (기능형 의수를 위한 텐스그리티 관절 구조 기반의 유연하고 가벼운 로봇 핸드 개발)

  • Geon Lee;Youngjin Choi
    • The Journal of Korea Robotics Society
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    • v.19 no.1
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    • pp.1-7
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    • 2024
  • This paper presents an under-actuated robotic hand inspired by the ligamentous structure of the human hand for a prosthetic application. The joint mechanisms are based on the concept of a tensegrity structure formed by elastic strings. These rigid bodies and elastic strings in the mechanism emulate the phalanx bones and primary ligaments found in human finger joints. As a result, the proposed hand inherently possesses compliant characteristics, ensuring robust adaptability during grasping and when interacting with physical environments. For the practical implementation of the tensegrity-based joint mechanism, we detail the installation of the strings and the routing of the driving tendon, which are related to extension and flexion, respectively. Additionally, we have designed the palm structure of the proposed hand to facilitate opposition and tripod grips between the fingers and thumb, taking into account the transverse arch of the human palm. In conclusion, we tested a prototype of the proposed hand to evaluate its motion and grasping capabilities.

Effect of Muscle Taping and Joint Taping on Static and Dynamic Balance in Normal Adults with Chronic Ankle Instability

  • Kim, Hyun-Sung;Park, Jae-Young
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.1
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    • pp.101-108
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    • 2022
  • Purpose : This study was conducted to investigate the effect of muscle taping and joint taping on static and dynamic balance in normal adults with chronic ankle instability. Methods : The subjects of this study were 32 people who met the inclusion criteria. This cross-sectional study was conducted using the Kinesio tape, an elastic tape, was used. Subjects were randomized to exclude the effect of sequence, and no taping, joint taping, and muscle taping were applied as taping interventions. One-leg standing test and a Functional reach test were conducted to measure static balance, and Y-balance test was conducted to measure dynamic balance. One way repeated ANOVA was performed to investigate the difference in balance ability according to the taping intervention. If there was a significant difference, a post-hoc was performed using the Bonferroni method. Results : In the case of static balance, joint taping showed more significant results than did no taping and muscle taping (p<.05), and muscle taping showed more significant results than did no taping (p<.05). In the case of dynamic balance, muscle taping showed significantly larger results than did no taping and joint taping (p<.05) and joint taping showed significantly larger results than did no taping (p<.05). Conclusion : This study found that mechanical stimulation of muscles and joint compression by elastic taping increased ankle stability and improved static and dynamic balance. In particular, for static balance, joint taping was more effective than muscle taping, and for dynamic balance, muscle taping was more effective than joint taping. Applying the appropriate taping method to individual subjects has the advantage of maximizing the therapeutic effect for the recovery of balance ability. Similarly, the application of various tapings to subjects with ankle instability will have a positive effect on functional improvement.

The impact of joint mobilization with an elastic taping on immediate standing balance in patients with knee osteoarthritis. (무릎 관절염 환자에 대한 관절가동술과 탄력 테이핑 융복합 적용이 즉각적인 기립 균형에 미치는 영향)

  • Park, Shin-Jun;Kim, Dong-Dae
    • Journal of the Korea Convergence Society
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    • v.8 no.7
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    • pp.295-304
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    • 2017
  • The purpose of this study was to identify the immediate effect of the joint mobilization with an elastic taping on standing balance in patients with knee osteoarthritis. Thirty patients with knee osteoarthritis were randomly divided into three groups: a taping group, a joint mobilization group, and a joint mobilization with taping group. A foot pressure platform (Zebris) was used to evaluate standing balance ability, and the sway area, path length and average velocity were measured during eyes open condition and eyes closed condition. All the groups showed a significant improvement in the sway area during eyes closed condition after intervention, and the joint mobilization with taping group revealed significant improvements in the path length and average velocity. There was no significant difference in the standing balance ability among all the groups. Both the joint mobilization and taping method were effective methods for standing balance during eyes closed condition, and it has been found that the convergence of the two interventions had an effect on diverse balance variables. Thus, it is recommended to apply the convergence of the two interventions for patients with knee osteoarthritis.

Comparison of gait ability according to types of assistive device for ankle joint of chronic hemiplegic stroke survivors (발목관절 보조 도구에 따른 만성 뇌졸중 편마비 장애인의 보행 비교)

  • Park, Dong-Chun;Jung, Jung-Hee;Kim, Won-Deuk;Son, Il-Hyun;Lee, Yang-Jin;Lee, GyuChang
    • Journal of Korean Physical Therapy Science
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    • v.28 no.2
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    • pp.30-39
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    • 2021
  • Background: The purpose of this study was to compare the differences in gait and mobility according to the types of assistive device for ankle joint including ankle foot orthosis (AFO), non-elastic tape, elastic tape, and high ankle shoes in chronic hemiplegic stroke survivors. Design: A cross-over design. Methods: Twelve hemiplegic stroke survivors participated in this study, and they walked under 5 different conditions including bare feet, wearing a AFO, wearing a non-elastic tape, wearing a elastic tape, and wearing a high ankle shoes. During the participants walked, the spatio-temporal gait analysis and mobility examinations were performed. For the spatio-temporal gait analysis (gait velocity and cadence, step length, stride length, and single and double leg support time) and mobility examinations, the gait mat, TUG and TUDS were used. Results: As s results, on the AFO, non-elastic tape, elastic tape, and high ankle shoes, there were significantly differences in the all spatio-temporal gait parameters, TUG, and TUDS compared to barefoot (p<0.05). In particular, all spatio-temporal gait parameters, TUG, TUDS were significantly improved with AFO compared to barefoot. TUG was significantly improved with AFO compared to non-elastic tape, TUG and TUDS were significantly improved with AFO compared to elastic tape, gait velocity was significantly improved with non-elastic tape compared to high ankle shoes, gait velocity and TUG were significantly improved with elastic tape compared to high ankle shoes, and TUDS was significantly improved with non-elastic tape compared to elastic tape. Conclusion: The AFO, non-elastic tape, elastic tape, and high ankle shoes showed a positive effect on gait and mobility compared to barefoot, and among them, wearing AFO was most effective for improving gait and mobility of chronic hemiplegic stroke survivors.