• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.243-252
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• 1987

The propagation and closure behavior of surface crack initiated at a sharply notched specimens were investigated in 5083-H113 aluminium alloy under constant amplitude of tension load by the unloading elastic compliance method. The crack shape (aspect ratio) was found to be approximately semicircular during the crack was being small and to be changed to semi-elliptical during it was being long. The propagation rate of a surface crack initiated from notch root decelerated with increasing crack length when the crack was small and then accelerated when it was large. The effect of stress ratio was large in lower .DELTA.K range, but the effective stress intensity factor range .DELTA.K$_{eff}$ was found to diminish the difference of the crack propagation rate. By considering the increase in crack closure stress with crack length and examining the microphotographs, plasticity-induced and roughness-induced crack closure mechanisms were predominant in the range of this study.y.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2229-2236
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• 2020

Background: Few comparative studies have been conducted on strengthening the anterior and posterior muscles of the trunk via lumbar stabilization exercises. Objectives: To compare the effects of forward leaning exercise and supine bridging exercise in stability exercise. Design: Randomized controlled clinical trial (single blind). Methods: Thirty subjects with spondylolisthesis were participated in this study. Fifteen subjects performed the bridging exercises and fifteen subjects performed the forward leaning exercises. Each exercise was held for ten seconds per repetition, and four repetitions were considered one sub-session. A total of four sub-sessions were performed in one full exercise session. The full exercise session required thirty minutes, including rest time. Trunk strength and range of motion and Oswestry disability index were measured. Results: Two weeks later, trunk flexion strength and trunk extension range of motion were significantly increased in the forward leaning exercise group than in the supine bridging group, trunk extension strength were significantly increased in the supine bridging exercise group than in the forward leaning group. After two weeks, the pain score was significantly lower in the forward leaning exercise group than in the supine bridging group. Conclusion: This study has shown that stabilization exercises are effective in increasing range of motion and strength in spondylolisthesis subjects. It was especially confirmed that the method of strengthening the anterior muscles of the trunk is more effective than the standard stabilization exercise method.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.2
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• pp.1-7
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• 2016

Background: The purpose of this study was to investigate the effects of between modified mulligan technique and modified mulligan technique with taping on the active range of motion & passive range of motion, scapula index into the stroke patients. Methods: The subjects with stroke were randomly divided into two groups. Group 1 (n=9) was conducted modified mulligan technique and Group 2 (n=9) was conducted modified mulligan technique with taping week three times for 4weeks. Active range of motion (AROM), passive range of motion (PROM) and scapula index (SI) were measured by goniometer and tape measure. Wilcoxon signed-rank tests were used to compare differences before and after intervention. Mann-Whitney U-test were conducted to compare before to after intervention in the two groups. Results: AROM was significantly different both groups (p<.05) and between groups were not significantly different into pre and post intervention (p>.05). PROM was significantly different both groups (p<.05) however, between groups were not significantly different into pre and post intervention (p>.05). SI was significantly different only group 2 and between groups were not significantly different (p>.05). Conclusions: This study demonstrated effective bo-th modified mulligan technique and modified mulligan technique with taping on the active range of motion and passive range of motion. Because only modified mulligan technique with taping are effective on the scapula index we recommend modified mulligan technique with taping than modified mulligan technique.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.2
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• pp.43-51
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• 2018

PURPOSE: Stroke patients have limited ankle range of motion and balance problems. The purpose of this study was to determine the effects of Kaltenborn orthopedic manual therapy, Evjenth-hamberg stretching, and combination of both on ankle dorsiflexion range of motion and dynamic balance ability in stroke patients. METHODS: Thirty patients were placed in three groups, each of which received different treatments: Kaltenborn orthopedic manual therapy (15 mins), Evjenth-hamberg stretching (15 mins), or Kaltenborn orthopedic manual therapy with Evjenth-hamberg stretching (30 mins). Each group received three exercise sessions per week during four weeks. To determine its effectiveness of interventions an evaluation was carried out. ankle dorsiflexion range of motion was gauged using a tiltmeter application, and dynamic balance ability was measured using the Berg balance scale. RESULTS: All groups revealed significant improvements in ankle dorsiflexion range of motion, Berg Balance Scale (BBS) score before and after the intervention, and Kaltenborn orthopedic manual therapy with Evjenth-hamberg stretching group showed a significant improvement in ankle dorsiflexion range of motion and BBS score in comparison to other groups. CONCLUSION: We found out that each individual method was effective in ankle dorsiflexion range of motion, dynamic balance ability in stroke patients, and the combined method was more effective.

• PNF and Movement
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• v.22 no.2
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• pp.191-199
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• 2024

Purpose: This study aimed to investigate the effects of ankle stretching with intrinsic muscles on ankle range of motion, static and dynamic balance, and gait speed in chronic stroke patients. Methods: The participants were 20 chronic stroke patients, divided into two groups, 10 in the ankle stretching with intrinsic muscles group and 10 in the slant board exercise group. Both groups performed their respective interventions once daily, with three sets per session, five times a week for four weeks. Ankle range of motion, dynamic and static balance, and gait speed were measured before and after the intervention. An independent t-test was used to compare the results between the two groups before and after the intervention. Results: Both groups showed significant improvements in ankle range of motion, dynamic and static balance, and gait speed after the intervention (p < .05). The ankle stretching with intrinsic muscles group showed more significant improvements in ankle range of motion, dynamic and static balance, and gait speed after the intervention compared to the slant board group (p < .05). These results suggest that ankle stretching with intrinsic muscles may be more effective than the slant board for certain outcomes. Conclusion: Ankle stretching with intrinsic muscles is effective in improving ankle range of motion, dynamic and static balance, and walking speed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.178-183
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• 1998

This paper examines the crack growth behavior of 7075-T651 and 5052-H32 aluminum alloys for variable load within tensile load range condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure are investgated by compliance method. The applied initial stress ratio is R=0.3 and variable load are R=0.65, 0.46. Crack length, stress intensity factor range, ratio of effective stress intensity factor range and crack growth rate etc. are inspected with fracture mechanics estimate.

• Journal of environmental and Sanitary engineering
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• v.10 no.2
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• pp.30-35
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• 1995

In this research effect of physicochemical parameter on flocculation using PASS-100 were evaluated. pEt flocculant dosage, mixing intensity and detention time were adopted as experimental variables. The physicochemical parameter( p% mixing intensity and mixing time ) were important Parameter on flocculation performance. Effluent pH range for effective flocculation was 4.5-7. Optimum Gt$_{d}$ range was 20,000-30,000 and its range similar to alum flucculation. Rapid mixing was very important parameter to floe formation in PASS- 100 flocculation. Whereas, slow mixing did not affect to the removal efficiency at settling time for 30minute or more.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.267-268
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• 2007

A dynamic range compression algorithm using Markov random field (MRF) modeling to display high dynamic range (HDR) images on low dynamic range (LDR) devices is proposed in this work. The proposed algorithm separates foreground objects from the background using the edge information, and then compresses the color differences across the edges based on the MRF modeling. By minimizing a cost function using belief propagation, the proposed algorithm can provide an effective LDR image. Simulation results show that the proposed algorithm provides good results.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.89-96
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• 2003

A new method to control the free spectral range of a long period fiber grating is proposed and theoretically analyzed. As the refractive index decreases radially outward in the silica cladding due to graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indices change and subsequently the phase matching conditions for coupling with the core mode in a long period fiber grating. Enlargement of the free spectral range in a long period fiber grating was theoretically confirmed.

• Journal of Sensor Science and Technology
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• v.19 no.2
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• pp.92-98
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• 2010

The capacitive sensor has a simple structure, compact size and low cost, but a small dynamic range. The small range is caused by use of gap variation. If the sensor takes area variation type with one plate moving horizontally, it can have a large measurable range. While the area variation has relatively low sensitivity, some studies have found methods to improve the sensitivity. Even though the methods are effective, parameters of the results are limited and 2 dimensional. This study provides more practical and 3 dimensional analysis and suggests relations between parameters. Using the results, the optimized design parameters of a high dynamic range capacitive sensor can be found.