• International Journal of Highway Engineering
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• v.13 no.2
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• pp.9-20
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• 2011

Most of domestic expansion joint system was applied by exposed expansion joint system. There are cases where it is damaged by driving. As the result noise and impact happened, and the social cost due to frequent repair works is increasing. So based on the Asphalt Plug Joint(APJ) system that applied in the United States and Europe, new buried expansion joint system was lately developed a system of Buried Folding Lattice Joint(BFLJ) that changed substructure. In this research, we have tested for durability and flexibility performance of buried expansion joint system that based on the type of asphalt mixture. Also we have evaluated for durability of BFLJ system against vehicle load using accelerated pavement testing. As a result of the experiment, the developed BFLJ system gives high flexibility performance and resolves transformation concentration along the joint section more than APJ system. Also it could be seen that the BFLJ system could overcome the disadvantages of APJ and prevent early damage. Because surface deflection of BFLJ system against vehicle load was measured low, and sub system in the buried expansion joint system was not damaged against vehicle load.

• Steel and Composite Structures
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• v.24 no.4
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• pp.425-439
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• 2017

As a thin-walled structure, local joint flexibility (LJF) in a tubular structure is prominent, and it may produce significant effect on the static performance for the overall structure. This study presents a simplified analytical model to analyze the static behavior for a steel tubular structure with LJF. The presented model simplifies a tubular structure into a frame model consisted of beam elements with considering the LJFs at the connections between any two elements. Theoretical equations of the simplified analytical model are deduced. Through comparison with 3-D finite element results of two typical planar tubular structures consisted of T- and Y-joints respectively, the presented method is proved to be accurate. Furthermore, the effect of LJF on the overall performance of the two tubular structures (including the deflection and the internal forces) is also investigated, and it is found from analyses of internal forces and deformation that a rigid connection assumption in a frame model by using beam elements in finite element analysis can provide unsafe and inaccurate estimation.

• Ocean Systems Engineering
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• v.14 no.1
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• pp.1-16
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• 2024

This paper investigates the impact of local joint flexibility (LJF) on the fatigue life of jacket-type offshore platforms. Four sample platforms with varying geometric properties are modeled and analyzed using the Opensees software. The analysis considers the LJF of tubular joints through the equivalent element and flexible link approaches, and the results are compared to rigid modeling. Initially, modal analysis is conducted to examine the influence of LJF on the frequency content of the structure. Subsequently, fatigue analysis is performed to evaluate the fatigue life of the joints. The comparison of fatigue life reveals that incorporating LJF leads to reduced fatigue damage and a significant increase in the longevity of the joints in the studied platforms. Moreover, as the platform height increases, the effect of LJF on fatigue damage becomes more pronounced. In conclusion, considering LJF in fatigue analysis provides more accurate results compared to conventional methods. Therefore, it is essential to incorporate the effects of LJF in the analysis and design of offshore jacket platforms to ensure their structural integrity and longevity.

• Journal of muscle and joint health
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• v.10 no.2
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• pp.131-141
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• 2003

The purpose of this study was to examine the effects of self-help program on patients with chronic arthritis. This study was performed from 13th of August to 29th of October 2002. 30 arthritis patients with an average age of 56 years were participated in the self-help program. At the completion of 6 weeks, 23 patients completed both pretest and posttest, overall dropout rate was 23%. Outcome measures were status of daily living, self-care activities, flexibility, grip strength and depression. Data were analysed by percentage, paired t-test, Pearson's correlation coefficient. There were statistically significant in self-care activities, flexibility, grip strength after the self-help program. However no significant differences were found in daily living and depression. There were significant relationships between daily living and depression. There were significant relationships between right flexibility & left flexibility and right and left grip strength. In conclusion self-help program was proved to be an effective nursing intervention to increase the self-care activities, flexibility and grip strength. These results of this study suggested that the follow-up program after the self-help program should be run to help the physical psychological wellbeing of arthritis patients.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3066-3074
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• 1994

This paper addresses the residual vibration problem of robots due to joint flexibility excited by fast accelerations, which has not been easily solved with conventional closed loop controllers. In this paper, an open loop input shaping technique, proposed by singer, has been applied to a 3 DOF robot with joint flexibility. In conjunction to the technique, a closed loop controller based on time-delay controller was also used. The results of simulations and experiments showed that the technique is quite effective for suppressing the residual vibration.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.619-629
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• 2017

This paper focuses on the study of complete dynamic modeling and maximum dynamic load carrying capacity computation of N-flexible links and N-flexible joints mobile manipulator undergoing large deformation. Nonlinear dynamic analysis relies on the Timoshenko theory of beams. In order to model the system completely and precisely, structural and joint flexibility, nonlinear strain-displacement relationship, payload, and non-holonomic constraints will be considered to. A finite element solution method based on mixed method is applied to model the shear deformation. This procedure is considerably more involved than displacement based element and shear deformation can be readily included without inducing the shear locking in the element. Another goal of this paper is to present a computational procedure for determination of the maximum dynamic load of geometrically nonlinear manipulators with structural and joint flexibility. An effective measure named as Moment-Height Stability (MHS) measure is applied to consider the dynamic stability of a wheeled mobile manipulator. Simulations are performed for mobile base manipulator with two flexible links and joints. The results represent that dynamic stability constraint is sensitive when calculating the maximum carrying load. Furthermore, by changing the trajectory of end effector, allowable load also changes. The effect of torsional spring parameter on the joint deformation is investigated in a parametric sensitivity study. The findings show that, by the increase of torsional stiffness, the behavior of system approaches to a system with rigid joints and allowable load of robot is also enhanced. A comparison is also made between the results obtained from small and large deformation models. Fluctuation range in obtained figures for angular displacement of links and end effector path is bigger for large deformation model. Experimental results are also provided to validate the theoretical model and these have good agreement with the simulated results.

• Journal of muscle and joint health
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• v.11 no.2
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• pp.127-135
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• 2004

Purpose: The purpose of this study was to explore the effects of aquatic exercise program on pain, flexibility, grip strength, self-care activities, helplessness in osteoarthritis patients. Methods: This program was carried out three times a week for 6 weeks by 3 groups of patients among 42 patients in regular swimming pool. Data were analysed by paired t-test for pre and post comparison. Results: There were significantly improved in pain flexibility, grip strength, self-care activities and helplessness after the program. However no significant differences were found in fatigue, difficulty of daily living activities and depression. Conclusion: Aquatic program was proved to be an effective nursing intervention to increase the self-care activities flexibility and grip strength, and to decrease pain and helplessness in osteoarthritis patients.

• Journal of muscle and joint health
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• v.17 no.1
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• pp.5-13
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• 2010

Purpose: The purpose of this study was to compare the effects of stretching exercise and aquatic exercise program on flexibility, pain and quality of life (QoL) in patients with osteoarthritis. Methods: Fifty elderly women were assigned either to the stretching exercise (SEG, n=25) or to the aquatic exercise groups (AEG, n=25) after 6-week self-help education program. SEG carried out supervised stretching exercise and water exercise training program was conducted by AEG (60 min/day, 2 days/wk) for 8 weeks. Flexibility, pain, and quality of life were measured by Senior Fitness Test Manual (Rikli & Jones, 2gr5), pain rating scale (0-10) and the questionnaire by World Health Organization Quality of Life BREF (Min et al., 2gr0), respectively. Results: Both SEG (all, p&H;.05) and AEG (all, p&H;.05) increased left upper and lower-body flexibility, measured by a measuring tape. Pain significantly decreased both in SEG (p=.000) and AEG (p=.004). Quality of life was significantly improved only for the SEG. Conclusion: The 8-week stretching exercise program would significantly improve flexibility, pain control and QoL in patients with osteoarthritis.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.24 no.1
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• pp.23-29
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• 2018

Background: This study aimed to the effects of hip mobilization on pain, trunk flexibility, function for chronic low back pain patients. Methods: Patients were randomly assigned to control group (n=15) and experimental group (n=15). Both groups received conventional physical therapy, three times a week for four weeks. Experimental group was performed additional hip mobilization, three times a week for four weeks. All measurement of each subject were measured at pre-intervention and post-intervention (after 4 weeks). Results: Assessed items included the visual analog scale score (VAS), Korean version of the Oswestry disability Index (KODI) a significant reduction was observed post intervention compared to pre-intervention values in both group (p<.01). Trunk flexibility was significant increased post intervention compared to pre-intervention values in both group (p<.01). There were significant difference between two groups in VAS (p<.01), trunk flexibility (p<.05) and except KODI. Conclusions: Our results indicate that conventional physical therapy with the hip mobilization may be useful for improving chronic low back pain patient.

• Journal of muscle and joint health
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• v.12 no.1
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• pp.69-80
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• 2005

Purpose: The purpose of this study was to analyse the effects of Tai Chi on the muscle strength and flexibility. Method: 10 articles from Medline search of foreign journals(1981-2003) and 4 from Korean nursing journals (1981-2003) were surveyed. The research are analyzed according to research design, subjects, and dependent variables. Results: Research on Tai Chi Exercise increased rapidly in the 1990's. The experimental research design was more reported than the comparative design. The experimental design included; 21.4% one group pre-posttest design, 35.7% quasi-experimental design and 28.6% randomized design. Out of the subjects; 64.4% of papers were healthy older people, and 35.6% of papers were patients with osteoarthritis or rheumatoid arthritis. Style of Tai Chi was mostly used Yang or Sun form. Muscle strength was usually measured at lower extremity or grip strength. Classical Yang style or Long form was more effective to improve muscle strength. 75% of papers were significantly improvement in grip strength and 71.4% of papers in flexibility. Conclusion: To properly study the positive effects of Tai Chi exercise, it is suggested that meta analysis needs to be done to integrate the various results.