• International Journal of Concrete Structures and Materials
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• 제5권1호
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• pp.19-28
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• 2011

This paper documents an experimental study of dynamic response of reinforced concrete beams following instantaneous removal of a bearing column. Four half-scale specimens representing two-span beam bridging across the removed column were tested. The test boundary conditions simulated rotational and longitudinal restraints imposed on a frame beam by the neighboring structural components. The gravity loads were simulated by attaching mass blocks on the beams at three locations. Dynamic loading effects due to sudden removal of a column were simulated by quickly releasing the supporting force at the middle of the specimens. The experimental study investigated the load-carrying capacity of beams restrained longitudinally at the boundaries and dynamic impact on forces. The tests confirmed the extra flexural strength provided by compressive arch action under dynamic loading. The tests also indicated that the dynamic amplification effects on forces were much lower than that assumed in the current design guideline for progressive collapse.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1641-1649
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• 2011

Dynamic response of high-speed railway bridges is important due to the possibility of resonance from continuous and repeated action of high-speed train running. The designer's decision and application affect the result of dynamic analysis significantly, therefore guideline for dynamic analysis is required. On the purpose of the selection of resonable model for dynamic analysis, this study investigated load distribution effect.

• 한국생산제조학회지
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• 제22권4호
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• pp.730-734
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• 2013

The dynamic simulation of machine tools and motion control systems has been widely used for optimization, design verification, control design, etc. There are three main streams in dynamic simulation: structural dynamic analysis based onthe finite element method, dynamic motion analysis based on equations of motion, and control system analysis based on transfer functions. Generally, one of these dynamic simulation methods is chosen and employed for specific purposes. In this study, an integrated dynamic simulation is introduced, in which the structure, motion, and control dynamics are combined together. Commercially well-known software is used in the integrated dynamic simulation: ANSYS, ADAMS, and Matlab/Simulink. Using the integrated dynamic simulation, the dynamics of a magnetic bearing stage is analyzed and the causes of oscillation and noise are identified. A controller design for suppressing a flexible dynamic mode is carried out and verified through the integrated dynamic simulation.

• Physical Therapy Rehabilitation Science
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• 제12권1호
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• pp.56-61
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• 2023

Objective: Core training is a key exercise for conditioning and fitness programs, injury prevention, and more. This study aimed to find out the effect of adding dynamic core training, which is frequently prescribed in clinical practice, on dynamic balance and muscle activity compared to conventional static core training. Design: An experimental study Methods: This study is an experimental pilot study of prospective parallel design. Six healthy young adults were allocated to static core training group (SCG; crunch and plank) and blended group (BG; crunch, plank, and dead bug exercise) for two weeks to perform core training. Dynamic balance and muscle activity (erector spinae, rectus abdominis) were measured for all participants before and after core training. Results: All six healthy young adults enrolled completed the study. No significant difference was found before and after 6 sessions of core training in each group (P>0.05). Likewise, no significant difference was found in the results of the difference comparison between groups (P>0.05). Conclusions: In conclusion, in this experimental study, no difference was found when dynamic core training was added. Although the results before and after core training did not show improvement in dynamic balance and muscle activity, a randomized controlled trial is needed considering the results of previous studies and the limitations of this experimental study.

• 한국조경학회지
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• 제27권3호
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• pp.39-49
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• 1999

The objective of this study is to characterize the landscape retaining dynamic character through the distinction between the spatial structure and the landscape. In this study, the landscape was characterized by the image of environment viewed by human being. Firstly, the landscape was disscussed in terms of such three element as the environment viewed by human being, the psychological detachment from the environment and the meaning of image. Secondly, the dynamic character of the landscape was determined by the comparision between the spatial structure of the static elements and the landscape experience through the case study Soshe garden. In the study found that landscape experience depend on the dynamic viewpoint and human views while the spatial structure is stable and static. This study also found that landscape is an open system which can be diachronically transformed by human value, while spatial structure is a synchronic closed system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.821-822
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• 2008

• 한국전문물리치료학회지
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• 제24권1호
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• pp.1-8
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• 2017

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group ($n_2=15$). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1117-1121
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• 2001

The dynamic behavior of slider is investigated using Dynamic Flying Height Tester(DFHT). The dependence of slider's dynamic fluctuation on disk velocity is measured, and a comparison is made with the computational result.

• 한국자동차공학회논문집
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• 제12권2호
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• pp.148-159
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• 2004

This paper discusses vibration mode of the drivesystem considered the vehicle body's dynamic characteristics to study the influence of the vehicle body's dynamic characteristics on the vibration mode of the engine mount system and the ride quality of a vehicle. The simulation model consists of the engine mount system, the powertrain and the rigid or elastic vehicle body. Variables used in this study are the stiffnesses of an engine mount system and the excitation forces. The Goals of the study are analyzing both the vibration transmitted to the vehicle body including the drivesystem and the influence of the vehicle body's dynamic characteristics on the engine mount system. The mode of drivesystems with a rigid and a elastic vehicle body was compared. From the result of the forced vibration analysis for the drivesystem with a elastic vehicle body, it is shown that the vehicle body's dynamic characteristics influence on the engine mount system reciprocally.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.342-347
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• 2004

The dynamic responses of a PSC bridge for automated guide-way transit system are investigated by analytical approach of bridge-vehicle interaction. In this study, the dynamic responses, concerned with a spall on the surface of bridge are emphasized. A simply supported pre-stressed concrete bridge is adopted as a numerical example. Dynamics of three-dimensional dynamic interaction system between bridges and vehicles is considered in this study. The FE method and modal analysis is used for modeling a bridge for dynamic response analysis. An AGT vehicle is idealized as a model with 11DOFs including lateral motion. It was found that the dynamic responses of bridge can be affected by a spall of surface. Especially, the vibrations are increased much more when a spall is exist.