• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.1
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• pp.32-45
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• 1995

This study was intended to evaluate condyle position and the relationship of condyle position change and post surgical relapse following the sagittal split ramus osteotomy for mandible setback in 25 patients by paired t-test and multiple regression analysis. We used oblique transcranial and cephalometric radiographs taken before operation, immediate after operation, and at least 6 months post operatively. 1. In oblique transcranial view, posterior joint space was decreased immediate after operation and increased 6 months after operation. To compare the measurement before and 6 months after operation, there was no statistically significant change in over all joint spaces(P>0.05). 2. The joint spaces changed under the 0.2mm were 30%, 0.2mm to 1.0mm were 60.7%, above 1.0mm were 9.3%. This result reveals that condyle position was relatively reproduced to pre-operative state. 3. Statistically, the amount of mandible set back didn't influence the post operative relapse(P>0.05). 4. Statistically, the amount of mandible set back didn't influence the condylar displacement(P>0.05), and the amount of joint space change didn't influence the post operative relapse.(P>0.05) The changes in joint space is in the standard tracing error or within the adaptive capacity of the individual, it was too small to influence the stability of surgery.

• Journal of Welding and Joining
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• v.28 no.2
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• pp.84-90
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• 2010

Fillet welding accounts for about 80% of all constructing process of ship and ocean structure. T-joint is one of the typical shapes which are frequently reported to experience the fatigue damage when the marine structure meets the storm loads. The fatigue damage is affected by the magnitude of residual stresses on the weld. Recently, many shipping registers and design guidances have required that the fatigue strength assessment method should be compensated by the effect of the residual stress in case that the random loading or storm loading is applied to the marine vessels. This study suggests the computational procedure to analyze the residual stresses of T-joint specimen that is frequently reported to get damaged by the storm loading. Experiment by XRD as well as the 3-D computational welding model is presented in order to get the profile of residual stress. Throughout the comparison of experimental result with the computational result, the computational model was validated. Thereafter, characteristics of he residual stresses in the joint are discussed.

• International Journal of Korean Welding Society
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• v.5 no.1
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• pp.60-65
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• 2005

In the field of welding the mechanical behavior of a welded structure under consideration may be predicted via heat transfer and welding residual stress analysis. Usually such numerical analyses are limited to small regular mesh models or test specimens. Nevertheless, there is very few strength assessment of the whole structure that includes the effect of welded residual stress. The present work is based on the specialized finite element codes for the calculation of nonlinear heat transfer details and residual stress including the external load on the welded RHS (Rectangular Hollow Section) T-joint connections of the whole structure. First the thermal history of the combined fillet and butt-welded T-joint equal width cold-formed RHS are calculated using nonlinear finite element analysis (FEA) considering the quarter model of the joint. Then using this thermal history the residual stress around the joints has been evaluated. To validity the FEA result, the calculated residual stresses were compared with the available experimental results. The residual stress obtained from the quarter model is mapped to the full model and then to the whole structure model using FEM codes. The results from the FEM codes were exported to the commercial package for visualization and further analysis applying loads and boundary conditions on the whole structure. The residual stress redistribution along with the external applied load is examined computationally.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.384-394
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• 2021

Objective: To quantitatively assess biochemical alterations in the cartilage of the subtalar and midtarsal joints in chronic lateral ankle instability (CLAI) patients with isolated anterior talofibular ligament (ATFL) injuries and combined calcaneofibular ligament (CFL) injuries using MRI T2 mapping. Materials and Methods: This study was performed according to regulations of the Committee for Human Research at our institution, and written informed consent was obtained from all participants. Forty CLAI patients (26 with isolated ATFL injuries and 14 with combined ATFL and CFL injuries) and 25 healthy subjects were recruited for this study. All participants underwent MRI scans with T2 mapping. Patients were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system. The subtalar and midtarsal joints were segmented into 14 cartilage subregions. The T2 value of each subregion was measured from T2 mapping images. Data were analyzed with ANOVA, the Student's t test, and Pearson's correlation coefficient. Results: T2 values of most subregions of the subtalar joint and the calcaneal facet of the calcaneocuboid joint in CLAI patients with combined CFL injuries were higher than those in healthy controls (all p < 0.05). However, there were no significant differences in T2 values in subtalar and midtarsal joints between patients with isolated ATFL injuries and healthy controls (all p > 0.05). Moreover, T2 values of the medial talar subregions of the posterior subtalar joint in patients with combined CFL injuries showed negative correlations with the AOFAS scores (r = -0.687, p = 0.007; r = -0.609, p = 0.021, respectively). Conclusion: CLAI with combined CFL injuries can lead to cartilage degeneration in subtalar and calcaneocuboid joints, while an isolated ATFL injury might not have a significant impact on the cartilage in these joints.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.48-55
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• 1998

This study was undertaken to investigate the friction welding of A2024-T6 aluminum alloy and SM45C carbon steel using insert metals. The relationships among the friction welding conditions, the tensile strength of joints, the hardness distribution of welds, the microstructure of welds and the tensile fracture surfaces were mainly investigated through this experiment. When the A6063-T5 aluminum alloy of insert metal was used, the maximum tensile strengh of joint was obtained. In this case, the maximum joint efficiency was 75.3 percent and in the case of unusing the insert metals, it was 37.7 percent. Optimal welding conditions were N=2000rpm, P$_1$=40MPa, P$_2$=140MPa, t$_1$=1.0sec and t$_2$=5sec.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.847-848
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• 2013

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1639-1646
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• 2001

It is often necessary that the joints characteristics should be determined in the early stage of the vehicle body design. The researches on identification of joints in a vehicle body have been performed until the recent year. In this study, the joint characteristics of vehicle structure were expressed as the condensed matrix forms from the full joint stiffness matrix. The condensed joint stiffness matrix was applied to typical T-type and Edge-type joints, and the usefulness was confirmed. In addition, it was applied to the real center pillar model and the full vehicle body in order to validate the practical application.

• Journal of Korean Physical Therapy Science
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• v.19 no.3
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• pp.57-62
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• 2012

Background and Purpose : This study was to analysis effects of muscle fatigue on error of elbow joint sense. Methods : A total 19 healthy student(men = 10, women = 9) who did't have any problem of musculoskeletal system in upper extremities participated this study. we divided two groups into young group(n = 10, $19.67{\pm}.5$) and old group(n = 9, $28.56{\pm}1.5$). In order to evoke muscle fatigue of elbow flexor, we used Biodex, and participations performed concentric contraction of elbow flexor 150 numbers as well as we measured error of joint sense using by Biodex. We collected data just after, 30min, 2hour, 24hour after evoked muscle fatigue, and we finanlly acquired average value of three times measured joint sense of elbow joint. And we calculated value of percentage of error of joint sense. We analyzed collected data by repeated ANOVA, ANOVA using by SPSS ver.12.0 program. Result : This study showed that there was no significantly effects between groups and within groups, we could see that there was significantly difference among duration by each group of age, and sex(p<.05). Conclusion : The error of joint position sense presented highest value just period after evoked muscle fatigue compared after 30 min, 2 hours, 24 hours, and we can't find out interaction between duration and age and sex.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.328-335
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• 1999

This study was designed to investigate the effects of exercise therapy on joint mobility, daily activity. pain and depression of patients with ankylosing spondylitis. 25 persons with the experimental group and 25 persons with the control group were conveniently sampled among out-patients diagnosed with ankylosing spondylitis at the rheumatism center of H University Medical Center. The control patients were matched to the experimental group and they were selected considering sex and age. The exercise therapy was developed by the author with the assistance of exercise specialists. The program includes muscle relaxation, flexibility, muscle strengths, breathing strengths and straight posture exercises. The 20-minute exercise therapy was carried out to the experimental group once a day for eight weeks from October. 1997 to February, 1998. Before and after the experiments, joint mobility, daily activity, pain and depression were measured respectively. Data were analyzed by $\chi$$^2$-test. t-test, paired t-test and unpaired t-test. The results were as follows : Joint mobility(cervical flexion, extension, shoulder flexion, abduction, hip abduction, knee flexion and fingertip to floor distance) and daily activity in the experimental group after the exercise were significantly increased than that in the control group. The pain and depression score in the experimental group after the exercise were significantly decreased than that in the control group. These findings may indicate that the exercise therapy is effective in increasing the joint mobility and daily activity, and also effective in decreasing pain and depression in patients with ankylosing spondylitis, Accordingly, the exercise therapy can be adopted as an effective nursing intervention for ankylosing spondylitis.

• Journal of Korean Biological Nursing Science
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• v.19 no.3
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• pp.191-197
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• 2017

Purpose: The aim of this study was to determine the effectiveness of a community-based muscle and joint self-management program with muscle stretching and muscle strengthening exercises for community-dwelling older adults. Methods: The study was a pre-and-post design in a single group, which examined the effects after the intervention of muscle and joint self-management program for 6 weeks, on the 42 subjects of the elderly who registered in a Community Senior Center in J city. Data analyses were conducted with paired t-test by using a SAS (version 9.2 for Windows) program. Results: The effectiveness of muscle and joint self-management program on shoulder flexibility and right knee extension (flexibility) were significantly improved (t= 2.72, p= .010; t= -2.26, p= .029). Joint symptoms (pain, stiffness), physical functioning, depression, fatigue, and left knee extension were not significantly improved after the muscle and joint self-management program. Conclusion: The results showed the possibility of this 6-week exercise program in improving shoulder and knee flexibility for community-dwelling older adults.