• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.475-481
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• 2014

Objective : To evaluate the anatomical feasibility of 3.5 mm screw into the cervical spine in the pediatric population and to establish useful guidelines for their placement. Methods : A total of 37 cervical spine computerized tomography scans (24 boys and 13 girls) were included in this study. All patients were younger than 10 years of age at the time of evaluation for the period of 2007-2011. Results : For the C1 screw placement, entry point height (EPH) was the most restrictive factor (47.3% patients were larger than 3.5 mm). All C2 lamina had a height larger than 3.5 mm and 68.8% (51/74) of C2 lamina had a width thicker than 3.5 mm. For C2 pedicle width, 55.4% (41/74) of cases were larger than 3.5 mm, while 58.1% (43/74) of pedicle heights were larger than 3.5 mm. For pedicle width of subaxial spine, 75.7% (C3), 73% (C4), 82.4% (C5), 89.2% (C6), and 98.1% (C7, 1/54) were greater than 3.5 mm. Mean lamina width of subaxial cervical spine was 3.1 (C3), 2.7 (C4), 2.9 (C5), 3.8 (C6), and 4.0 mm (C7), respectively. Only 34.6% (127/370) of subaxial (C3-7) lamina thickness were greater than 3.5 mm. Mean length of lateral mass for the lateral mass screw placement was 9.28 (C3), 9.08 (C4), 8.81 (C5), 8.98 (C6), and 10.38 mm (C7). Conclusion : C1 lateral mass fixation could be limited by the morphometrics of lateral mass height. C2 translamina approach is preferable to C2 pedicle screw fixation. In subaxial spines, pedicle screw placement was preferable to trans-lamina screw placement, except at C7.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.25-30
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• 2000

Ion mass doping method has been implemented for the fabrication of large area electronic devices such as TFT-LCD. In this work, the effect of ion mass doping on the velocity and the behavior of MILC was investigated. When amorphous silicon was either doped or bombarded by accelerated ions, MILC velocity was reduced by over 50% and the front edge of MILC became coarse. In order to analyze the dependence of silicon film's properties on ion mass doping, ultraviolet reflectance and sulfate roughness were investigated. Both the velocity and the behavior of MILC were found to be related with the increase of surface roughness by ion bombardment.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.150-157
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• 2005

The vibration system in this study is consisted of a rotating cantilever pipe conveying fluid and a tip mass. The equation of motion is derived by using the Lagrange's equation. The influences of the rotating angular velocity and the velocity of fluid flow on the natural frequencies of a cantilever pipe have been studied by the numerical method. The effects of a tip mass on the natural frequencies of a rotating cantilever pipe are also studied. The influences of a tip mass, the velocity of fluid, the angular velocity of a cantilever pipe and the coupling of these factors on the natural frequency of a cantilever pipe are analytically clarified. The natural frequencies of a cantilever pipe conveying fluid are proportional to the angular velocity of the pipe in both axial direction and lateral direction.

• Journal of Korean Neurosurgical Society
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• v.46 no.1
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• pp.74-76
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• 2009

We present an extremely rare case of the atypical choroid plexus papilloma in an adult which developed at the trigone of right lateral ventricle. A 62-year-old woman presented with the history of intermittent and gradually progressive headache and left side hemiparesis for 6 months. The brain magnetic resonance image showed highly enhanced and well demarcated mass at the trigone of lateral ventricle attached to the choroid plexus. Gross total resection was performed by transcortical approach via the middle temporal gyrus. The tumor was diagnosed as an atypical choroid plexus papilloma. She had no neurologic deficit after the surgery. We report a case of atypical choroid plexus papilloma in adult and introduce newly classified pathologic characteristics of this tumor.

• Journal of the Korean Society for Railway
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• v.4 no.3
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• pp.116-122
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• 2001

As freight traffic becomes heavier, the high speed of existing freight cars is essential, instead of the construction of a new railway. The high speed can be achieved by the modifications of freight bogie design. In this paper, an analytical model of freight bogie is developed to decide the critical speed. The dynamic responses of the analytical model are compared with the experimental data from a running test of freight bogie and showed good agreements between them. The analytical model is used to find the design of freight bogie. The parameter studies show that the reduction of wheelset mass ratio and the increase of the axle distance of freight bogie can increase the critical speed, but the primary lateral stiffness has little effects on the critical speed. And this study also shows that smaller wheel conicity deteriorates the running safety of freight car, which means that the overhauling of the wheel of freight bogie should be done regularly.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.464-466
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• 2010

A 59-year-old female presented with headache and dizziness for one year. Magnetic resonance imaging revealed a $52{\times}28$ mm, wellcircumscribed, homogenously enhancing mass lesion without dural attachment located in the left lateral cerebellomedullary cistern. The tumor was excised, and a histological diagnosis was a mixed pattern meningioma of meningothelial and fibroblastic type. A meningioma in the posterior fossa without dural attachment is quite rare. We report a rare case of lateral cerebellomedullary cistern meningioma without dural attachment with literature review.

• Korean Journal of Head & Neck Oncology
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• v.35 no.1
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• pp.37-40
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• 2019

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of malignant lymphoma (ML), accounting for only 1 to 2% of all non-Hodgkin's lymphoma (NHL). Although ML of the parotid gland is rare, the majority are B-cell types. The AITL occurring synchronously in the parotid gland and lateral neck has not been reported earlier. It is classified as a high-grade malignancy with aggressive clinical features, and the prognosis is worse than any other type of NHL. We recently encountered a 72-year-old man with multiple mass on the ipsilateral parotid tail and lateral neck, and he was finally diagnosed as AITL. We report the unique and rare disease entity with a brief literature review.

• Journal of Korean Neurosurgical Society
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• v.47 no.2
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• pp.148-150
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• 2010

Osteolipoma is an ossified lipoma with distinct components of fat and bone. We present a case of interhemispheric osteolipoma associated with total agenesis of the corpus callosum. A 20-year-old man complained of severe headache, nausea and vomiting. Brain computed tomography showed a low-density mass in an interhemispheric fissure, with high T1 and T2 magnetic resonance signals compatible with fat. The mass measured $4.9\;{\times}\;2.9\;cm$ in size and showed peripheral calcifications. There was another small piece of same signal mass within the lateral ventricular choroid plexus. The interhemispheric lesion was removed by an interhemispheric approach. Osteolipoma is rare in interhemispheric region, however, it should be a differential diagnosis of lesions with fat intensity mass and calcifications.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.561-565
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• 1990

We experienced thymolipoma which is a rare benign mediastinal tumor, an admixture of atrophic thymic tissue and matured adipose tissue. The patient was, 13 years old boy, admitted due to anterior mediastinal mass on routine chest X-ray and complained of mild exertional dyspnea. The physical examination revealed percussion dullness, decreased breathing sound at right anterior hemithorax. The chest PA and lateral views showed both paracardiac mass density and obliteration of retrosternal clear space. The chest CT Scan showed tubular structure containing of thymic tissue and enhanced fatty tissue, suggested thymolipoma. Operation was performed under the impression of thymolipoma. Through median sternotomy, the huge mass was resected. Grossly, the mass was yellowish fatty colored, measured 15X12X10cm, weighed 600gm. Light microscopic examination showed that thymic tissue containing of Hassal`s corpuscles were surrounded by matured adipose tissue, as the characteristic finding of thymolipoma. The postoperative course was uneventful.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.9
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• pp.124-129
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• 1997

The purpose of this study is to predict the stability and frequency response of multipurpose vehicle. The vehicle model has seven degrees of freedom. The motion equations are derived by using Lagrangian equation and linearized. The positions of eigenvalues of model which are dominated by lateral velocity, yaw rate, roll rate of sprung mass are used to predict the stability of motion. The resonse of sprung mass to steering wheel is simulated in time domain. It is predicted that the roll response of sprung mass would rather be improved by modifying the position of eigenvalues. The responses of sprung mass to steering wheel are also simulated in frequency domain. The magnitude and phase plots of gains are evaluated in driver's steering input frequency range.