• 제목/요약/키워드: dynamic study

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외부 후긴장 공법 적용에 따른 무도상 판형교의 동적거동 분석 (A Study on Dynamic Behaviors of Steel Plate Girder bridge with Applying External Post-Tensioning Method)

  • 최동호;최정열;최준혁;박용걸
    • 한국철도학회논문집
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    • 제9권2호
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    • pp.160-168
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    • 2006
  • The major objective of this study is to investigate the effects and application of external post-tensioning method far steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis, field test and laboratory test fur the lateral dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the lateral dynamic response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease lateral acceleration and deflection on steel plate girder bridge for serviceability. And the external post-tensioning method reduce dynamic maximum displacement(about $10{\sim}24%$), the increase of dynamic safety is predicted by adopting external post-tensioning method. From the dynamic test results of the servicing steel plate girder bridge, it is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method The servicing steel plate girder bridge with external post-tensioning has need of the reasonable reinforcement measures which could be reducing the effect of lateral dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

교량-AGT 차량 상호작용에 의한 교량의 동적응답 (Dynamic Response Analysis of Bridge-AGT Vehicle Interaction System)

  • 김현호;나상주;송재필
    • 한국철도학회논문집
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    • 제9권5호
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    • pp.561-568
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    • 2006
  • Dynamic equations of motion for the interaction system of bridge and vehicle are derived to investigate the dynamic responses of bridge and vehicles induced by moving automated guide-way transit(AGT) vehicle and surface roughness of bridge. The vehicle model for ACT vehicle is idealized as 11 DOF including yawing, lateral translation and steering of wheels, and the bridges are modeled with finite element method. The AGT vehicle model was verified by experimental study. Parametric studies are carried out to investigate the effect of vehicle speed, surface roughness, stiffness and damping of the suspension system, AGT vehicles and dynamic wheel loads of the AGT vehicles. From the parametric study it can be seen that the dynamic incremental factor of the bridge and dynamic responses of vehicles have a tendency to increase with vehicle speeds, surface roughness and the stiffness of AGT vehicle suspension system. On the other hand those dynamic wheel loads have tendencies to decrease in according to increase of damping of the suspension system.

Research on static and dynamic behaviors of PC track beam for straddle monorail transit system

  • Yang, Yongqing;Yang, Deng;Gou, Hongye;Bao, Yi
    • Steel and Composite Structures
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    • 제31권5호
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    • pp.437-452
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    • 2019
  • In this study, in-situ static and dynamic tests of four pre-stressed concrete (PC) track beams with different span lengths and curvatures in a straddle monorail transit system were reported. In the static load tests, the strain and deflection at critical sections of the PC track beams were measured to determine the load bearing capacity and stiffness. The dynamic responses of strain, deflection, acceleration, and displacement at key positions of the PC track beams were measured under different train speeds and train loads to systematically study the dynamic behaviors of the PC track beams. A three-dimensional finite element model of the track beam-vehicle coupled vibration system was established to help understand the dynamic behavior of the system, and the model was verified using the test results. The research results show that the curvature, span length, train speed, and train loads have significant influence on the dynamic responses of the PC track beams. The dynamic performance of the PC track beams in the curve section is susceptible to dynamic loads. Appropriate train loads can effectively reduce the impact of the train on the PC track beam. The PC track beams allow good riding comfort.

A method for dynamic analysis of frame-hinged shear wall structures

  • Bozdogan, Kanat Burak;Ozturk, Duygu
    • Earthquakes and Structures
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    • 제11권1호
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    • pp.45-61
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    • 2016
  • Structures with soft story irregularity have been seriously damaged in earthquakes. Therefore, the analysis of dynamic behavior of structures with soft story irregularity is of great value and relevance. In this study, a certain method will be used to discover the displacements and internal forces and to find out results about soft story irregularity. For this study, the multi-story frame-hinged shear wall system has been used as a model according to the continuous calculation system. The dynamic characteristics of the system have been obtained by analyzing the governing differential equation of the system. The dynamic characteristics have been calculated for a practical and quick analysis as indicated in tables. The suggested method is wholly based on manual calculation. A spectral analysis can be easily conducted with the help of Tables provided by this study. A sample has been solved and compared to the finite elements method to study the suitability of the method suggested at the end of this study.

편마비 환자의 신발 높이 조절이 동적체중부하율에 미치는 영향 (The Effect of Shoe Lift of the Paretic Limb on Dynamic Weight Bearing in Hemiplegics)

  • 윤정규;김병욱
    • 대한물리치료과학회지
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    • 제8권2호
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    • pp.1073-1080
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    • 2001
  • The purpose of this study was to determine the effect of lift to the shoe of the affected limb on gait patterns in subjects with hemiplegia. The subjects of this study were 18 post-stroke hemiplegics. For the study, insole of the paretic side was lifted 10 mm higher, and duration of dynamic weight bearing was measured. before and after the lift application. For the measurement of carry-over effect of lift, we got data of there three items prior to and 3 weeks after lift application and 3 days after removal of the lift. Dynamic weight bearing was significantly decreased in heel contact and footflat phases only when just after application of the lift, without any change after 3 weeks application. In heel-off phase, dynamic weight bearing did not show any significant difference between before and just after application of lift whereas significantly decreased after 3 weeks application. According to this study, lift applied to the shoe of the paretic limb was not significantly effect in inducing dynamic weight bearing, but changed a dynamic weight bearing.

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Static or Dynamic Capital Structure Policy Behavior: Empirical Evidence from Indonesia

  • UTAMI, Elok Sri;GUMANTI, Tatang Ary;SUBROTO, Bambang;KHASANAH, Umrotul
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.71-79
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    • 2021
  • This study investigates the capital structure policy among Indonesian public companies. Previous studies suggest that capital structure policy could follow either static or dynamic behavior. The sample data used in this study was companies in the manufacturing sector, divided into three sub-sectors: the basic and chemical industry, miscellaneous industry, and the consumer goods industry. This study uses panel data from 2010 to 2018, with the Generalized Least Square (GLS) method and compared whether the fixed effect model is better than the common effect model. The results show that the dynamic and non-linear model tests can explain the capital structure determinants than the static and linear models. The dynamic model shows that the capital structure of a certain year is influenced by the capital structure of the previous year. The findings indicate that the company performs some adjustments in its capital structure policy by referring to the previous debt ratio, which implies support to the trade-off theory (TOT). The study also shows that profitability, tangible assets, size, and age explain the variation of capital structure policy. The patterns on the dynamic and non-linear confirm that capital structure runs in a nonlinear pattern, based on the sector, company condition, and the dynamic environment.

Immediate Effect of Hip Hinge Exercise Stretching on Flexibility of Lower Limb, Pelvic Tilting Angle, Proprioception and Dynamic Balance in Individual with Hamstring Tightness

  • Jung, Myeongeun;Kim, Namwoo;Lee, Yongwoo
    • Physical Therapy Rehabilitation Science
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    • 제11권2호
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    • pp.259-268
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    • 2022
  • Objective: The purpose of this study was to measure the immediate effect of hip hinge exercise stretching on hamstring flexibility, pelvic tilting angle, proprioception, and dynamic balance in individual with tightness of the hamstring. Design: A randomized controlled trial. Methods: A total of 35 healthy young adults (27 males, 8 females) volunteered for this study and randomly divided into three groups (Hip hinge exercise stretching group, passive stretching group, and PNF stretching group). The hamstring flexibility, pelvic tilting angle, knee joint proprioception, dynamic balance was conducted for 3 times. In order to evaluate the hamstring flexibility, the active knee extension test was performed. Forward bending test was performed to examine pelvic tilting angle.The proprioception was tested by the joint position sense test and dynamic balance was evaluated by Y balance test. Results: The hamstring flexibility, pelvic tilting angle and dynamic balance were significantly improved between three groups before and after intervention (p<0.05). Dynamic balance was significantly difference between the three groups in the posterolateral direction (p<0.05). Conclusions: This study result showed that hip hinge exercise stretching was the most effective method for increasing hamstring flexibility, pelvic tilting angle and dynamic balance. In addition, it is necessary to study whether hamstring stretching is effective in low back pain patient with hamstrings tightness.

The Impact of Knowledge Management and Dynamic Capacity on the Ambidextrous Innovation of Korean MNCs in the Chinese Market

  • Yu, Xin-Ran;Kim, Tae-In
    • Journal of Korea Trade
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    • 제24권1호
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    • pp.99-112
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    • 2020
  • Purpose - With the increasing uncertainty of China's domestic political and economic environment in recent years, Korean MNC subsidiaries in the Chinese market face greater challenges and competition. Based on the insufficiency of existing research and the need for enterprise management practices, this paper uses the Chinese subsidiaries of Korean MNCs as an example to study and explore how knowledge management and dynamic capabilities affect ambidextrous innovation and the relationship between ambidextrous innovation and subsidiary performance. Design/methodology - From January to March 2019, this study collected 341 valid questionnaires using a survey company specializing in China for the members of the Chinese subsidiaries of Korean MNCs to verify the hypotheses. Using the collected data, the study model was verified using the Smart PLS 3.0 statistical package. Findings - Knowledge transfer and knowledge sharing have positive effects on dynamic capabilities and ambidextrous innovation, and dynamic capabilities have a positive impact on ambidextrous innovation. Ambidextrous innovation has been shown to have a significant effect on subsidiary performance. In addition, a partial mediating effect of dynamic capabilities on the relationship between knowledge management and ambidexterity innovation was found. Originality/value - In the academic context, this paper contributes theoretically to the relationship between knowledge management and ambidextrous innovation, as well as the mechanism of dynamic capability, and to verify the relationship between ambidextrous innovation and corporate performance. Against the background of MNC management, the results of this study provide further enlightenment for managers of subsidiaries.

Comparison of viscous and kinetic dynamic relaxation methods in form-finding of membrane structures

  • Labbafi, S. Fatemeh;Sarafrazi, S. Reza;Kang, Thomas H.K.
    • Advances in Computational Design
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    • 제2권1호
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    • pp.71-87
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    • 2017
  • This study focuses on the efficiency and applicability of dynamic relaxation methods in form-finding of membrane structures. Membrane structures have large deformations that require complex nonlinear analysis. The first step of analysis of these structures is the form-finding process including a geometrically nonlinear analysis. Several numerical methods for form-finding have been introduced such as the dynamic relaxation, force density method, particle spring systems and the updated reference strategy. In the present study, dynamic relaxation method (DRM) is investigated. The dynamic relaxation method is an iterative process that is used for the static equilibrium analysis of geometrically nonlinear problems. Five different examples are used in this paper. To achieve the grading of the different dynamic relaxation methods in form-finding of membrane structures, a performance index is introduced. The results indicate that viscous damping methods show better performance than kinetic damping in finding the shapes of membrane structures.

팀 학습행동이 팀 효과성에 미치는 영향과 팀 동적역량의 매개효과 (The Effects of Team Learning Behavior on Team Effectiveness and the Mediating Effects of Team Dynamic Capabilities)

  • 이균재;홍아정
    • 지식경영연구
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    • 제15권4호
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    • pp.57-78
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    • 2014
  • Since team performance has become one of the core factors for companies' success, companies are putting every effort to raise team productivity. In this vein, the purpose of this study was to examine the influence of team learning behavior upon team dynamic capabilities, team effectiveness, and to verify the mediating effect of team dynamic capabilities in corporations. 312 employees were randomly selected to participate in an questionnaire survey. The result has shown that the static correlation exists between team learning behavior, team dynamic capabilities, and team effectiveness. Team dynamic capabilities mediated the relationship between team learning behavior and team effectiveness. Based on the findings, the study implies that learning behaviors among team members should be supported in order to improve its outcome, and HR representatives must help to develop dynamic capabilities.