• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.4 no.1
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• pp.31-41
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• 2009

Objectives: The aim of this study was to evaluate the evolution of lumbar disc herniation in patients treated with oriental medicine. Methods: 14patients(15 cases) with lumbar disc herniation proved at MRI(Magnetic resonance imaging) underwent a follow-up MRI study. Follow-up MRI was performed $4{\sim}14$months(mean 7 months) after initial MRI. Results & Conclusions: 1. 13 cases(87%) had reduction of disc herniation. 1 showed no change in amount of disc herniation. 1 had an increase in disc herniation. 2. Comparison initial MRI with follow-up MRI showed that 2 of the herniations decreased between 0% and 25%, 3 decreased between 25% and 50%, 5 decreased between 50% and 75%, 3 decreased between 75% and 100%. The size of the herniation decreased on average by 49% in 14patients(15 cases). 3. On axial images, the proportion of the cross-sectional area of the spinal canal occupied by the herniated disc was 54.41% on the average on the initial scan, 29.65% on the follow-up scan.

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.72-73
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• 2001

• The Journal of Korean Physical Therapy
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• v.21 no.3
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• pp.9-16
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• 2009

Purpose: The purpose of this study was to investigate the effects of intermittent lumbar traction and manual traction on a $L_{4-5}$ herniated disc. Method: The subjects were randomly divided into the intermittent lumbar traction group (n=10) and the manual traction group (n=10). The intermittent traction group had traction-treatment applied for 12 times in the first two weeks, and then 6 times in the next two weeks. The time the traction was applied was for 30 minutes. The manual traction group had flexion-distraction therapy applied for 12 times in first two weeks, and for 6 times in next two weeks. The time the traction was applied was 3 to 6 minutes per treatment. Results: The change of the muscle test (MT), the disc herniation index (DHI) and the sagittal $T_2$ weighted MRI was measured at pretreatment and 4weeks and 12weeks after treatment. Conclusion: We found that intermittent lumbar traction and manual traction could improved the MT and DHI and this could improve the rehabilitation of patients with lumbar herniated disc.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.105-112
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• 2010

Dual Pulse Rocket Motor is a solid rocket motor with two grains separated by a bulkhead and rupture disc. The elasto-plastic explicit dynamic analysis of rupture disc was conducted by finite element method. The effect of the slit geometry of a rupture disc was analyzed for rupture time and shape by the parametric study. The results can be used to control the rupture pressure by the change the slit geometry of a rupture disc.

• Journal of the Korean Orthopaedic Association
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• v.54 no.3
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• pp.237-243
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• 2019

Purpose: To analyze the risk factors for posterior migration of a single cage after transforminal lumbar interbody fusion (TLIF). Materials and Methods: This study was conducted retrospectively on 48 patients (60 discs) who were followed-up for 1 year after TLIF from January 2015 to January 2017. The patients were divided into two groups: group 1 containing 16 patients (17 discs) with cage migration and group 2 containing 32 patients (43 discs) without it. Information related to cage migration, such as the demographic factors, shape of disc, level and location of the cage inserted, and disc height change, was acquired from the medical records and radiologic images, and the possibility for generating posterior migration of cage was evaluated statistically. Results: The demographic factors and cage-inserted level were similar in the two groups (16 patients in group 1, 32 patients in group 2). In the migration group, number of patients with a pear-type disc, 9 patients, was significantly larger; the disc height change, 1.8 mm, was significantly smaller; and the cage was located frequently on non-center in the anteriorposterior view and center in the lateral view in 9 and 15 out of 16 patients, respectively. Conclusion: A pear-type disc shape, small disc height change, cage with non-center on the anteriorposterior view and non-anterior on the lateral view are the risk factors for posterior migration. These factors are important for preventing posterior migration of the cage.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.123-129
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• 2011

Purpose : To compare lumbar disc changes between initial lumbar spine (L-spine) MRI and follow-up (f/u) MRI that were performed due to recurred backaches. Materials and Methods : A total 50 patients who had undergone f/u L-spine MRI were retrospectively reviewed. Five discs (L1-S1) were surveyed in each f/u MRI. Lumbar disc changes were defined as no change, aggravations, or improvements compared to initial disc states. These states were defined on the basis of morphologic status and disc levels. Results : In a total of 250 discs in 50 patients, 31 discs (12.4%) showed morphologic changes of disc lesions, whereas 219 discs (87.6 %) showed no changes. Among the 31 disc lesions, 24 were aggravated and 7 were partially improved. And on the basis of disc status, initially abnormal discs revealed any morphologic changes of the degree of disc herniation. A total of 33.3% of the morphologic changes are noted in initially extruded discs. Fifteen morphologic changes of disc lesions were located at the L4-5 level. Conclusion : Our results suggest that correlations between lumbar disc herniations and back pain symptoms are limited, and that evaluations of extra disc lesions are required.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.665-669
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• 2007

This study investigates the temperature change and thermal conductivity for the braking disc of the railway vehicle due to the types of train and service conditions. The temperature change was measured by non-contact Infrared thermometers. Average temperature was measured between $79.32^{\circ}C$ and $104.46^{\circ}C$ due to types of train and service section. In the same service section, the surface temperatures of Saemaul train were higher than Mugungwha train; the reason might have been the average service speed of Saemaul train (83km/h) was higher than Mugungwha train (107km/h), and the weight was similar 39t (Mugungwha) and 39.3t (Saemaul). But the maximum surface temperature was measured on the Mugungwha train; however the difference was not too big with the maximum temperature of Saemaul train. Also, the disc surface temperatures were changed due to the material of lining; metal and non-asbestos, on the same train and the same service section. In addition. the thermal conductivity was tested the thermal conductivities were increased by the increasing of the temperature. The change is too big between $100^{\circ}C$ and $200^{\circ}C$. But each average value is small. and the mechanical property change is very low. As a result, we conclude that this disc is suitable for usage between $100^{\circ}C$ and $300^{\circ}C$.

• The Korean Journal of Health Service Management
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• v.8 no.2
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• pp.127-137
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• 2014

The purpose of this study is to investigate the relationship between behavior patterns(DISC) and direct indirect of social support from dental hygienists. The data used in this study were obtained from 171 dental hygienists who have been working on dental hospital or clinic in Pusan and Gyeongsangnam-do from 1st July to 30th August in 2011. In the level of direct indirect of social support according to subjects' general characteristics, higher educational level and non-religion was related with higher in direct of social support(p<0.05), and hygienists who worked in general hospital was related with higher indirect of social support(p<0.01). According to between behavior patterns(DISC) and indirect social support, these score were that I-type 3.55, D-type 3.53, C-type 3.41, and S-type 3.36. All behavior patterns(DISC) were similar with the indirect support. In direct support these score were that S-type 2.98 I-type 2.95, D-type and C-type 2.91. In frequency of behavior patterns(DISC), these were that I-type 56.7%, S-type 16.4%, C-type 14%, and D-type 12.9%. In correlation between factors, direction social support was correlated with I-type(p<.01) and C-type(p<.01) of behavior patterns(DISC). On based on these results, if the change of working environment, working condition will improve social support of dental hygienists. And education program have to developed for dental hygienists.

• Design & Manufacturing
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• v.16 no.4
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• pp.34-39
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• 2022

Sustained economic development around the world is accelerating resource depletion. Research and development of secondary batteries that can replace them is also being actively conducted. Secondary batteries are emerging as a key technology for carbon neutrality. The core of an electric vehicle is the battery (secondary battery). Therefore, in this study, the temperature change by the heat source of the hammer and the rotational speed (rpm) of the abrasive disc of the Classifier Separator Mill (CSM) was repeatedly calculated and analyzed using the heat flow simulation STAR-CCM+. As the rotational speed (rpm) of the abrasive disk increases, the convergence condition of the iteration increases. Under the condition that the inlet speed of the Classifier Separator Mill (CSM) and the heat source value of the disc hammer are the same, the disc rotation speed (rpm) and the hammer temperature are inversely proportional. As the rotational speed (rpm) of the disc increases, the hammer temperature decreases. However, since the wear rate of the secondary battery material increases due to the strong impact of the crushing rotational force, it is determined that an appropriate rpm setting is necessary. In CSM (Classifier Separator Mill), it is judged that the flow rate difference is not significantly different in the direction of the pressure outlet (Outlet 1) right above the classifier wheel with the fastest flow rate. Because the disc and hammer attachment technology is adhesive, the attachment point may deform when the temperature of the hammer rises. Therefore, it is considered necessary to develop high-performance adhesives and other adhesive technologies.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.363-368
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• 2001

Studies on brake system recently are focused on braking performance, especially the consideration on safety of braking system in an extreme situation and reduction of vibration and noise during braking operation. The thermal crack and Judder from the friction between brake disc and pad can bring the threaten of passengers' safety in the end. Braking force comes from the change of kinetic energy to friction energy. Since heat energy is developed from here, the analysis on thermal stress and thermal strain can be the good data when selecting the material of brake pad and designing heat radiation holes on the disc and it will also be the data when designing the thickness of the disc. This paper is intended to show a creative design method by suggesting the thermal analysis data through FEM study and using shape design parameters.