• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.257-264
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• 2019

The purpose of this study was to investigate effective intervention(upper thoracic mobilization and upper cervical mobilization) methods for forward head posture. 32 subjects were divided into two groups: upper thoracic mobilization(UTM) and upper cervical mobilization(UCM) on three times a week for a total of four weeks. In both groups significant difference in forward head posture pre and post test(p <.01), significant difference between the two groups (p <.05, 95% CI: .157-.341). In both groups significant difference in neck disability index pre and post test(p <.01), significant difference between the two groups (p <.01, 95% CI: 1.273-8.728). In both groups significant difference in quality of life pre and post test(p<.05), significant difference between the two groups (p <.01, 95% CI: 4.234-18.391). The results of this study showed that the UTM was more effective than that of the forward head posture. It would be possible to provide more effective interventions for patients with forward head posture and also to prevent secondary musculoskeletal disorders due to forward head posture.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.5
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• pp.297-305
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• 2006

The thermal ratcheting deformation at the reactor baffle and upper internal structure of the liquid metal reactor (LMR) can occur due to movement of the hot sodium free surface. In in-service inspection of reactor internals of LMR, a new inspection technique should be developed for the detection of the thermal ratcheting damage. In this study, an inspection technique using ultrasonic guided wave is proposed for the detection of the thermal ratcheting damage of cylindrical vessels. A 316L stainless steel cylindrical shell specimen has been prepared. The thermal ratchet structural tests were cyclically performed by heat-up up to $550^{\circ}C$ with steep temperature gradients along the axial direction after cool-down by cooling water. Ultrasonic guided wave propagation has been characterized by analysis of dispersion curve of the stainless steel plate. The zero-order antisymmetric $A_0$ guided wave has been selected as the optimal mode for detection of the ratcheting deformation. It is confirmed that the thermal ratcheting deformation can be detected by the measurement of transit time difference of circumferentially propagated $A_0$ guided waves.