• The Korean Journal of Pain
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• v.18 no.1
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• pp.56-59
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• 2005

The most effective treatment methods for a herniated lumbar disc remain questionable. This report follows the patients course, from the onset of pain through the completion of the non-surgical treatment, and shows that a lumbar herniated disc, with radiculopathy, can be successfully treated with a non-surgical approach. This report discusses the possible explanations for disc resorption: retraction into the intervertebral space, dehydration/shrinkage and resorption due to an inflammatory reaction. A non-surgical approach can be an effective treatment option for a herniated lumbar disc.

• Tribology and Lubricants
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• v.28 no.5
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• pp.246-251
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• 2012

Disc brakes and brake linings are part of the braking system in automobiles; this system works due to the braking power between the disc and pad. Vehicle braking systems have complex environments due to the geometry of the disk and pad, the material properties, the braking conditions, etc. Braking energy is converted into thermal energy during the braking process, due to the frictional heat between the disc brake and pad. This heat is changed to a heat flux, which affects the thermal stress of the disc. The purpose of this study was to use the fluid dynamics software ANSYS CFX to investigate the inner flow characteristics of the air and the heat transfer of the disc, and to analyze the effects on the thermal stress of the disc brake.

• Computers and Concrete
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• v.23 no.5
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• pp.303-309
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• 2019

This study investigates axisymmetric fractional vibration of an isotropic hyperelastic semi-linear thin disc with a view to examine effects of finite deformation associated with the material of the disc and effects of fractional vibration associated with the motion of the disc. The generalized three-dimensional equation of motion is reduced to an equivalent time fraction one-dimensional vibration equation. Using the method of variable separable, the resulting equation is further decomposed into second-order ordinary differential equation in spatial variable and fractional differential equation in temporal variable. The obtained solution of the fractional vibration problem under consideration is described by product of one-parameter Mittag-Leffler and Bessel functions in temporal and spatial variables respectively. The obtained solution reduces to the solution of the free vibration problem in literature. Finally, and amongst other things, the Cauchy's stress distribution in thin disc under finite deformation exhibits nonlinearity with respect to the displacement fields whereas in infinitesimal deformation hypothesis, these stresses exhibit linear relation with the displacement field.

• Journal of Technologic Dentistry
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• v.42 no.4
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• pp.388-393
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• 2020

Purpose: This study aims to understand the relationship between university major satisfaction and job preference according to DISC behavior patterns. Methods: To conduct our evaluation, we surveyed a group of 118 students from the Department of Dental Laboratory Technology at the college of Jinju city from August 31 to September 11, 2020. The collected data was evaluated through frequency analysis, descriptive statistics analysis, one-way ANOVA, and regression analysis. Results: The analysis revealed that the steadiness type had the highest and the dominance type had the lowest major satisfaction level by DISC behavior type. The job preference was different for each DISC behavior type, and higher the preference for stability and development, the higher the degree of satisfaction with the major. Conclusion: These results suggest that DISC behavior type, major satisfaction, and job preference are all related. Therefore, these factors should be considered when implementing career guidance and educational programs for college students.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.173-189
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• 2000

The purpose of this study was to evaluate the effect of specific head positions on the mandibular rotational torque movements in maximum mouth opening, protrusion and lateral excursion. Thirty dental students without any sign or symptom of temporomandibular disorders(TMDs) were included as a control group and 90 patients with TMDs were selected and examined by routine diagnostic procedure for TMDs including radiographs and were classified into 3 subgroups : disc displacement with reduction, disc displacement without reduction, and degenerative joint disease. Mandibular rotational torque movements were observed in four head postures: upright head posture(NHP), upward head posture(UHP), downward head posture(DHP), and forward head posture(FHP). For UHP, the head was inclined 30 degrees upward: for DHP, the head was inclined 30 degrees downward: for FHP, the head was positioned 4cm forward. These positions were adjusted with the use of cervical range-of-motion instrumentation(CROM, Performance Attainment Inc., St. Paul, U.S.A.). Mandibular rotational torque movements were monitored with the Rotate program of BioPAK system (Bioresearch Inc., WI, U.S.A.). The rotational torque movements in frontal and horizontal plane during mandibular border movement were recorded with two parameters: frontal rotational torque angle and horizontal rotational torque angle. The data obtained was analyzed by the SAS/Stat program. The obtained results were as follows : 1. The control group showed significantly larger mandibular rotational angles in UHP than those in DHP and FHP during maximum mouth opening in both frontal and horizontal planes. Disc displacement with reduction group showed significantly larger mandibular rotational angles in DHP and FHP than those in NHP during lateral excursion to the affected and non-affected sides in both frontal and horizontal planes(p<0.05). 2. Disc displacement without reduction group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening as well as lateral excursion to the affected and non-affected sides in both frontal and horizontal planes. Degenerative joint disease group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening, protrusion and lateral excursion in both frontal and horizontal planes(p<0.05). 3. In NHP, mandibular rotational angle of the control group was significantly larger than that of any other patient subgroups. Mandibular rotational angle of disc displacement with reduction group was significantly larger than that of disc displacement without reduction group during maximum mouth opening in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group or degenerative joint disease group during maximum mouth opening in the horizontal plane(p<0.05). 4. In NHP, mandibular rotational angles of disc displacement without reduction group were significantly larger than those of the control group or disc displacement with reduction group during lateral excursion to the affected side in both frontal and horizontal planes. Mandibular rotational angle of disc displacement without reduction group was significantly smaller than that of the control group during lateral excursion to the non-affected side in frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group during lateral excursion to the non-affected side in the horizontal plane(p<0.05). 5. In NHP, mandibular rotational angle of the control group was significantly smaller than that of disc displacement with reduction group or disc displacement without reduction group during protrusion in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of the disc displacement with reduction group or degenerative joint disease group during protrusion in the horizontal plane. Mandibular rotational angle of the control group was significantly smaller than that of disc displacement without reduction group or degenerative joint disease group during protrusion in the horizontal plane(p<0.05). 6. In NHP, disc displacement without reduction group and degenerative joint disease group showed significantly larger mandibular rotational angles during lateral excursion to the affected side than during lateral excursion to the non-affected side in both frontal and horizontal planes(p<0.05). The findings indicate that changes in head posture can influence mandibular rotational torque movements. The more advanced state is a progressive stage of TMDs, the more influenced by FHP are mandibular rotational torque movements of the patients with TMDs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1051-1061
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• 2004

In this Paper, a new antenna(VHMDA) characteristics of half-circular/elliptical disc-loaded planar antennas with horizontally top-loaded small disc is studied by simulation and measurements with additional resonant structure. The transfer function characteristics of Gaussian pulse from the designed UWB transmitter antenna has been investigated. The radiation pattern of the proposed antenna in azimuth is nearly omni-directional response, which is usulally required in conventional monopole antenna. In addition to that, the simulation and measured results show that the return loss characteristics of VHDMA covers considerably large bandwidth with small area. From the measured results of the circular and half-circular disc-loaded monopole antennas with small disc mounted on the top, it is found that the half disc-loaded monopole antenna with additional structure can be comparable to the circular disc-loaded monopole antenna in respect o( size and electrical performances. Surface wave and dielectric losses often caused by the printed antenna using high dielectric constant does not occur in metallic planar antenna with good impedance matching and without lossy matching unit. This structure implies that the performance of return loss is directly related with the radiation efficiency.

• The Journal of Korean Physical Therapy
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• v.18 no.6
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• pp.43-49
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• 2006

Purpose: Changes of degenerative disc have been analyzed or with the Magnetic Resonance Imaging (MRI) to assign appropriate meaning, and the relationship between the degenerative changes of the discs and its living function has been evaluated through the living function evaluation scores collected by functional rating index. Methods: in April, 2006, a physical examination was conducted for physical laborers to be employed as on-site laborer in a steel industrial complex located at a region. A month later, these 20 laborers who participated in lumbar vertebra MRI tests have been investigated for one-to-one mobile phone functional rating index test. Excluding 3 of 14 respondents whom scored 0 in functional rating index, the rest of respondents' degenerative disc grade changes shown in MRI and its relationship to living functional rating index have been performed. Results: The Dabbs method of measuring disc height resulted to show significant increase as the disc height changes from L1-2 level to L5-S1 level (p<0.01). However, there was no statistical significance with a relationship between disc height and functional rating index, and disc height average. The Magnetic Resonance Imaging analysis regard on the degree of disc degeneration and its relationship to living functional rating proved to have significant relationship (p<0.05). Conclusion: The degenerative changes monitored by Magnetic Resonance Imaging show significant relationship (p<0.05) to living function. However, this relationship could vary depend upon the characteristics of study population. So, it suggested that the future studies should be performed by considering population's age and job career.

• Korean Journal of Acupuncture
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• v.27 no.4
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• pp.5-13
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• 2010

Objectives : Herniated lumbar intervertebral disc is common reason causing back pain. Lumbar stabilization exercise prevent back pain recurrence by strengthening lumbar muscles. Sling Exercise Therapy(SET) is a system for spinal muscle stabilization and strengthening using fixed string and mobile band. The purpose of this study is to investigate and measure the effectiveness of SET and oriental medicine for Herniated lumbar intervertebral disc. Methods : The subjects for this study are 40 patients suffering from Herniated lumbar intervertebral disc in our clinic. They were measured and compared by Visual Analogue Scale(VAS), 4 grades of recovery degree and sex, age, period of disease, disc herniation type, times of exercise. Results : In the above index, the score(VAS, 4 grades of recovery degree) improved after treatments. But they make no difference between sex, age, period of disease, disc herniation type and times of exercise. Conclusions : These results suggest that SET may be used for Herniated lumbar intervertebral disc for pain management and muscle strengthening as an essential treatment regardless of sex, age, period of disease and disc herniation type.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.628-634
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• 2000

Objective : The introduction of MRI makes it easy to detect multiple lumbar disc herniation. However, MRI is not a physiologic test for detecting the symptomatic level. For the surgical plan, it is very important to determine the symtomatic level among the multiple lumbar disc herniation. In this regard, we studied diagnostic significance of discography on multiple lumbar disc herniation in determining the symptomatic level. Method and Material : We retrospectvely analyzed the discographic and clinical findings of 121 patients with multiple lumbar disc herniation for investigating the diagnostic availability of discography. All were surgically treated from January 1995 through May 1998. Result : Discography provocated the same pain as usual symptom in 99 out of 121 patients(81.8%). Compared with surgical findings, the diagnostic accuracy of the discography in multiple lumbar disc herniation was 75.6%, sensitivity was 64.6%, and specificity 87.2%. There was no correlation between the pain provocation of discography and the extent of annular degeneration on CT/discogram. The pain provocation showed good correlation with the extent of annular disruption on CT/discogram. The rate of same result(correlation rate) between the discography and D.I.T.I was 81.4% in multiple lumbar disc herniation patients with unilateral leg pain. Conclusion : These results indicate that in multiple lumbar disc herniation, the discography is considered useful diagnostic tool to determine the symptomatic level and to decide the surgical plan.

• The Journal of Korean Physical Therapy
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• v.13 no.1
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• pp.1-18
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• 2001

Aging has been recognized as the primary cause of disc degeneration. A biomechanical characteristics of disc degeneration has been demonstrated that intradiscal pressure is reduced. With the increasing population of elderly people, disc degeneration and associated problems of nerve entrapment are becoming more prevalent. Presently, research on reduced intradiscal pressure associated with degeneration is insufficient. In this study. we used the Finite Element Method (FEM) of computerized simulations to investigate the effects of variation in intradiscal pressure on mechanical behaviours of L4-5 intervertebral disc degeneration. Degeneration was classified using four grades based on initial intradiscal pressure; Normal (135 kPa), mild(107 kPa), moderate (47 kPa) and severe (15 kPa). The predicted results f3r bending loads were as follows; 1 . Range of motion increased progressively with severity of degeneration with flexion and lateral bending moments, but decreased with extension moments. 2. Discal bulging of posterolateral aspect was larger in lateral bending and extension moment. But bulging was increased with severity of degeneration in lateral bending and torsion(same side).3. The rate of increasing intradiscal pressure was decreased in all bending motions with severity of degeneration. In conclusion, lateral bending and extension moment yield greatest bulging in severe degeneration. In torsion, although bending load produces disc bulging, disc bulging was associated more strongly with severity of degeneration than increasing torsional moments. Clinical Implications: Discal bulging may produce nerve root impingement and irritation. The effect of loading and posture on the varying degrees of disc degeneration has important implications especially in the elderly. In the presence of disc degeneration, avoidance of end range postures, especially extension and lateral bending may help reduce discal bulging and in turn, nerve entrapment.