• Journal of Korean Neurosurgical Society
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• v.41 no.2
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• pp.137-140
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• 2007

HNP [Herniation of the necleus pulposus] generally occurs at ventral portion of lumbar thecal sac due to the anatomical position. We report two unusual cases of herniated dorsal portion of lumbar thecal sac causing diagnostic difficulties. Two patients with posteriorly migrated epidural disc fragments were evaluated with plain X-ray, and magnetic resonance imaging. These patients responded well to operation with complete relief of symptoms. Definite diagnosis of posteriorly located disc fragments is difficult because the radiological images of disc fragments may mimic those of other more common posterior epidural lesions.

• Journal of Korean Dental Science
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• v.8 no.1
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• pp.16-27
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• 2015

Purpose: The purpose of this study was to evaluate the correlation between the clinical symptoms of temporomandibular disorder and findings in the magnetic resonance imaging (MRI). Materials and Methods: Clinical data and MRI images were collected from a total of 240 German patients. Clinical symptoms were briefed as joint clicking, crepitus and pain. MRI findings were further defined according to the condyle position, condyle degeneration, disc positon, disc degeneration and the presence of osteophyte/sclerosis/synovitis. Hypermobility was separately recorded. Correlation analysis between parameters was performed. Result: Joint clicking had a positive correlation with unilateral disc degeneration, osteophyte, sclerosis and synovitis. Crepitus had a significant correlation with bilateral osteophyte. Pain was not correlated with any MRI findings except hypermobility. Conclusion: Selective correlations between the MRI findings and clinical symptoms were elucidated. The results of this study imply that condyle-disc deformities could be advanced without pain, and that joint clicking and crepitus could be clinical symptoms of condyle-disc degeneration.

• Journal of KSNVE
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• v.4 no.3
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• pp.319-325
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• 1994

The flucturation of the engine torque appears to be the major source of the torsional vibration of the automotive driveline. The reduction of this torsional vibration has become a significant problem, due to an increase in the flucturation of the torque of recent light weighted powered engines, along with the requirements of higher performance. The torsional vibration of the automotive driveline can be reduced by soothing the fluctuation by adjusting the torsional characteristics of the clutch-disc. Computer simulation of the engine- input gear train is a useful investigative tool on studying the torsional characteristics of the clutch-disc. In this paper, a dynamic model for the automotive driveline was developed, and the engine torque and drag torque of the model were evaluated withe experimental data. By executing a simulation using the model, it has become possible to obtain the clutch-disc torsional characteristics when the engine is idling and the clucth-disc torsional characteristics for reducing the torsional vibration has been suggested.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.505-510
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• 2009

The possible causes of Brown-S$\acute{e}$quard Syndrome (BSS) have been frequently observed with spinal trauma and extramedullary spinal tumors, but the cervical disc herniation to cause BSS is rare. The authors present five cases of patients who were diagnosed with BSS resulting from cervical disc herniation, and the results of the literature in view of their distinctive symptoms and clinical outcomes. Postoperatively, the patients showed complete or almost complete recovery from their motor and sensory deficits. On the basis of our cases, it is important to diagnose it early by cervical magnetic resonance imaging, especially in the absence of the typical symptoms of cervical disc herniation or other obvious etiology of extremity numbness. Immediate surgical treatment is also essential for a favorable functional neurological recovery.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.788-793
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• 2002

Hybrid type slim tilt actuator and 6-wire supported are developed for DVD recording in the optical disc drive of notebook PC, which can compensate the inclination of disc and objective lens. The hybrid actuator uses the actuating method of moving coil in the focus and track direction and that of moving magnet in the tilt direction. Comparing with 6-wire supported actuator and hybrid type actuator, we can choose an actuator for slim super combo pickup. Two actuator are designed through the modal analysis and magnetic field analysis and experimental results shows dynamic characteristics. Finally, it is verified that the actuator can compensate the disc tilt of ${\pm}0.4^{\circ}$.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.1092-1098
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• 2009

The squeal propensity of an automotive disc brake system is studied in the theoretical and computational manner. The rotating disc is in contact with two stationary pads and the nonlinear friction is engaged on the contact surface. The friction-coupled equations of motion are derived in the finite element(FE) of the actual brake disc and pad. From the general definition of friction force, the rotation and in-plane mode effects can be included properly in the brake squeal model. The eigenvalue sensitivity analysis and the mode shape visualization at squeal frequencies are also conducted for the detailed investigation. It is found that the squeal propensity is strongly influenced by rotation effect and the in-plane mode can be involved in squeal generation.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.419-420
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• 2007

Low back pain is common during pregnancy. However, the prevalence of symtomatic lumbar disc herniation is rare, and cauda equina syndrome due to disc herniation during pregnancy is even rarer. We report a rare case of lumbar disc herniation causing cauda equina syndrome during third trimester of pregnancy which successfully treated by endoscopic discectomy. This case shows that endoscopic discectomy can be the treatment option for the lumbar disc herniation during pregnancy.

• Journal of Korean Neurosurgical Society
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• v.49 no.1
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• pp.61-64
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• 2011

Upper thoracic vertebral bodies are difficult to access using standard anterior approaches. It may require sternotomy and claviculectomy, which carries significant possibility of morbidities. We report a case of inferiorly migrated cervicothoracic junction disc treated successfully by anterior upper-vertebral transcorporeal approach. This specific technique obviated the need of sternotomy, created favorable working space and saved the motion segment at cervicothoracic junction. This report is the first transcorporeal approach to a disc fragment at T1-2 space without fusion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.666-669
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• 2011

The rupture disc shapes of bulkhead type pulse separation device(PSD) are designed for new dual pulse rocket motor. Before final design PSD, that three different rupture disc are tested and confirmed the performance of the discs. Through analyzing the test results the PSD decides, two rupture disc shapes with flow holes of eight circles and eight trapezoids.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.62-66
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• 2012

The authors report 2 cases of nerve root herniation after discectomy of a large lumbar disc herniation caused by an unrecognized dural tear. Patients complained of the abrupt onset of radiating pain after lumbar discectomy. Magnetic resonance imaging showed cerebrospinal fluid signal in the disc space and nerve root displacement into the disc space. Symptoms improved after the herniated nerve root was repositioned. Clinical symptoms and suggestive radiologic image findings are important for early diagnosis and treatment.