• Journal of the Korean Society for Precision Engineering
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• v.9 no.1
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• pp.75-81
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• 1992

In this paper, an impact vibration absorber that reduces the high vibration amplitude of a vibrating system is studied. This absorber consists of a free mass allowed to impact on to the secondary leaf spring so that the vibration energy is dissipated by converaion into noise and heat. The experimental parameters are weight of the free mass and impat clearance. According to the measured results, the high vibration in resonance region is reduced more effectively by the impact clearance ratio than by the mass ratio.

• Journal of Chest Surgery
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• v.28 no.8
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• pp.784-787
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• 1995

A 3-year old female who underwent modified Fontan operation for the double outlet right ventricle with hypoplastic left ventricle at the age of 15 month was admitted with hemoptysis, which was developed 4 days prior to visit. Cardiac catheterization revealed that multiple collaterals from descending thoracic aorta supplied the right lung and drained to the right pulmonary artery. Chest magnetic resonance imaging [MRI showed that the right lung was consolidated by the secondary long-term pulmonary congestion. We decided to perform pneumonectomy because the consolidated right lung and the back-flow from the right pulmonary aretry would worsen the present hemodynamic state of patient. Post-operative course was uneventful, and she could be discharged with good general conditions.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2508-2511
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• 1999

A non-contact battery charger which transfers energy using magnetic field without any electrical contacts is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the non-contact transformer and ZVS operation can reduce switching losses. In this paper. analysis and design procedure of half-bridge series resonant converter with non-contact transformer is presented. Input voltage is 85VAC ${\sim}$ 270VAC, output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method for calculating the secondary current of the transformer to control battery charging current in constant current charging mode which is required for litium-ion battery is proposed and the performance is verified from experiments.

• BMB Reports
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• v.41 no.1
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• pp.35-40
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• 2008

The molten globular conformation of V26A ubiquitin (valine to alanine mutation at residue 26) was studied by nuclear magnetic resonance spectroscopy in conjunction with amide hydrogen/deuterium exchange. Most of the amide protons that are involved in the native secondary structures were observed to be protected in the molten globule state with the protection factors from 1.2 to 6.7. These protection factors are about 2 to 6 orders of magnitude smaller than those of the native state. These observations indicate that V26A molten globule has native-like backbone structure with marginal stability. The comparison of amide protection factors of V26A ubiquitin molten globule state with those of initial collapsed state of the wild type ubiquitin suggests that V26A ubiquitin molten globule state is located close to unfolded state in the folding reaction coordinate. It is considered that V26A ubiquitin molten globule is useful model to study early events in protein folding reaction.

• Annals of Clinical Neurophysiology
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• v.7 no.1
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• pp.49-51
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• 2005

A 61-year-old man with an antecedent febrile illness presented with progressive flaccid paraparesis, but no sensory or sphincter involvement. Magnetic resonance imaging (MRI) of the spine was negative and nerve conduction study (NCS) showed the absence of F-waves in his legs, suggesting $Guillain-Barr{\acute{e}}$ syndrome (GBS). However, abdominal pain after admission led to the consideration of the spinal cord ischemia secondary to aortic dissection confirmed by computed tomography. We report the rare condition of painless aortic dissection simulating GBS.

• Journal of Korean Neurosurgical Society
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• v.51 no.4
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• pp.219-221
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• 2012

A 20-month-old boy presented with a intraparenchymal mass in the right frontoparietal area manifesting as complex partial seizure, secondary generalization and left hemiparesis. Magnetic resonance images (MRI) of the brain showed inhomogeneously enhancing mass in the right frontoparietal area which has irregular margin and perilesional edema. Based on the radiological findings, a preoperative diagnosis was an intraaxial tumor, such as pilocytic astrocytoma or dysembryoplastic neuroepithelial tumor. The patient underwent a surgery including frontal craniotomy. The tumor had a partially extreme adherence to the surrounding brain tissue but it showed no dural attachment. Gross-total resection of the tumor was achieved. Postoperative follow-up computed tomography scans showed no residual tumor. The pathological findings confirmed the tumor as a WHO grade I meningioma, transitional type. Nine months after the surgery, follow-up brain MRI showed no recurrence of the tumor, porencephaly in site where the tumor was resected; the patient's symptoms had fully recovered. We report the case of a meningioma in a 20-month-old boy.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.2
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• pp.95-105
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• 2005

Cleft lip and palate is a congenital deformity which needs a professional and consistent management from the birth and along with the physical growth of patients. The patients with cleft lip and palate can have general speech problems with resonance disorders, voice disorders and articulation disorders after the successful primary surgical management and the physical growth. Speech problems of Cleft lip and palate are characterized hypernasality, nasal air emission, increased nasal air flow, and aberrant speech marks which decrease intelligibility. These speech problems of cleft lip and palate can be treated with the secondary surgical procedure, the application of temporary prosthesis and the effective and well-timed speech therapy. The speech and language problems of cleft lip and palate, the general procedures and schedules of the speech assessment and therapy based on the multidisciplinary approach are introduced for the patients with cleft lip and palate, their family and the other members of the cleft palate treatment team.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.48-50
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• 2010

Spontaneous intracranial hypotension is often idiopathic. We report on a patient presenting with symptomatic intracranial hypotension and pain radiating to the right leg caused by a transdurallumbar disc herniation. Magnetic resonance (MR) imaging of the brain revealed classic signs of intracranial hypotension, and an additional spinal MR confirmed a lumbar transdural herniated disc as the cause. The patient was treated with a partial hemilaminectomy and discectomy. We were able to find the source of cerebrospinal fluid leak, and packed it with epidural glue and gelfoam. Postoperatively, the patient's headache and log radiating pain resolved and there-was no neurological deficit. Thus, in this case, lumbar disc herniation may have been a cause of spontaneous intracranial hypotension.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.216-221
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• 2004

The performance of secondary suspension is one of the most important characteristics of railway vehicles in the regard of vibration and riding comfort. For this reason, the suspension shall be designed to absorb vibration energy effectively and to avoid the resonance which would be occurred by the vibration of the bogies in driving. The main factor of characteristics of suspension is spring coefficient of air spring, and this paper shows how to achieve the desired coefficient and the results of the tests of new air springs.

• Journal of Korean Foot and Ankle Society
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• v.7 no.2
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• pp.269-273
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• 2003

Although osteochondromas are common lesions, osteochondroma accompanying diastasis of the ankle joint in a child or adult is an uncommon condition. No previous cases of distal tibiofibular diastasis caused by an osteochondroma in adult have been reported except in child. The authurs experienced a case of mild distal tibiofibular diastasis secondary to an osteochondroma in a 37-year-old female presented with right ankle pain. Osteochondroma of the distal tibiofibular joint were detected on magnetic resonance imaging (MRI). She was pain-free 4 weeks after excision of the osteochondroma. The patient has remained asymptomatic for 1 years postoperatively. Early excision obviates the need for complex reconstructive surgery to correct ankle deformity later.