• Journal of Korean Neurosurgical Society
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• v.55 no.2
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• pp.99-102
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• 2014

A previously healthy 52-year-old man presented to the emergency room with acute onset left hemiparesis and dysarthria. Brain computed tomography and magnetic resonance examinations revealed acute cerebral infarction in the right middle cerebral artery territory and a sphenoid ridge meningioma encasing the right carotid artery terminus. Cerebral angiography demonstrated complete occlusion of the right proximal M1 portion. A computed tomography perfusion study showed a wide area of perfusion-diffusion mismatch. Over the ensuing 48 hours, left sided weakness deteriorated despite medical treatment. Emergency extracranial-intracranial bypass was performed using a double-barrel technique, leaving the tumor as it was, and subsequently his neurological function was improved dramatically. We present a rare case of sphenoid ridge meningioma causing acute cerebral infarction as a result of middle cerebral artery compression.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.26-27
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• 1994

The first step implementation of a hospital-wide Picture Archiving Communications System (PACS) at a newly built hospital Samsung Medical Center (SMC), is described. Current clinical operation encompasses the fiber optics delivery of direct-interfaced magnetic resonance imager (LRI), X-ray computed tomography (CT). digital subtraction angiography (DSA) and computed radiography (CR) digital images via high performance file server to the departments of radiology, neurosurgery, orthopedics surgery, neurology, emergency room and the surgical intensive care unit.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.10
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• pp.35-41
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• 1992

Ultra-thin silicon nitride films were fabricated with ECR(Electron cyclotron Resonance) nitrogen plasma at room temperature. Film thickness was about 50$\AA$ after nitridation for 1min at microwave power of 1000W, RF power of 500W, and NS12T pressure of ${\times}10^{-3}$ torr. 50$\AA$ fo nitride film was grown within 1 min and no appreciable growth occured thereafter. Dielectric breakdown strength and leakage current density in Al/SiN/Si structure were measured to be about 7-11 MV/cm and ${\times}10^{-10}~5{\times}10^{-10}A/cm^{2}$, respectively. Observed linear relationship in 1n(J/E)-vs-E$^{1/2}$ and no polarity-dependence of the leakage current indicated that the Poole-Frenkel emission is mainly responsible for the conduction in this nitrided silicon films.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.479-485
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• 2000

In this study, the chamber size was designed and manufactured so as to make a resonance with microwaves in sterilizing moisture-contained food by making good use of microwaves. When the green-pea jelly which was made and sterilized for experimental usage with no addition of an antiseptic was left in the room temperature for 1 minute, 2 minutes or 3 minutes respectively, resulted in delaying more greatly the procession of change in quality of food for almost 7 to 15 days than in unsterilized food. As a result of experiment conducted above, it is considered to produce good results of decreasing the resource waste and environmental pollution, by lengthening the period of preservation and circulation of food.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1989.06a
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• pp.114-117
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• 1989

An infrasonic wide band transducer fabricated by polytetrafluoroethylene(PTFE)is studied experimentally. The sensitivity of the transducer depends largely on the surface charge of the Electret and is typically between-50 and -62[dBV] for a sound-pressure level of 1[ubar]. The sensitivity of the transducer does not decay over periods of the order of years at room temperature. The frequency response is within 1.5[dB] from 1 to 6,000[Hz] and within 12[dB] from 0.05[Hz] to 1[Hz] respectively. The resonance frequency of the element is 510 [Hz]. We conjectures that the element is applicable to accustics, communication system, seismological observation and other similar filed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.250-250
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• 2008

This paper describes the resonant characteristics of polycrystalline SiC micro resonators. The $1{\mu}m$ thick polycrystalline 3C-SiC cantilevers with different lengths were fabricated using a surface micromachining technique. Polycrystalline 3C-SiC micro resonators were actuated by piezoelectric element and their fundamental resonance was measured by a laser vibrometer in vacuum at room temperature. For the 100 ~ $40{\mu}m$ long cantilevers, the fundamental frequency appeared at 147.2 kHz - 856.3 kHz. The $100{\mu}m$ and $80{\mu}m$ long cantilevers have second mode resonant frequency at 857.5 kHz and 1.14 MHz. Therefore, polycrystalline 3C-SiC micro resonators are suitable for RF MEMS devices and bio/chemical sensor applications.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.5
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• pp.550-557
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• 2008

A transmission control cable connects the transmission control arm and the control lever mechanically and transfers control effort exerted by a driver to the transmission. It also transfers vibration generated by the engine to the passenger room through mechanical connection. To understand vibration and noise transfer mechanism and to further find a way to suppress the transmission of vibration effectively, a dependable dynamic vibration model is a necessity. A vibration model for a transmission control cable is developed and a simulation study has been conducted to obtain mode frequencies and a transmittability. The resonance frequencies obtained by an harmonic analysis is compared with the noise level measurement data. The measurement agrees with the simulation result thus ensures the reliability of the model.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.83-90
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• 2007

The vehicle dynamic control system needs to detect the yaw rate of vehicle and a yaw rate sensor is required as a central component. Therefore, A sensor on the basic of the "tuning fork method" for automotive controls is being developed. The sensor was fabricated by the surface micro machining process to miniaturize its size. The sensor output offset is ${\pm}0.37^{\circ}/sec$ in the room temperature. The resonance frequency of the fabricated yaw rate sensor is measured to 5.29kHz for the drive mode. Tests of the sensor demonstrate that its performance is equivalent to that required for implementation of a yaw control system. Vehicle handling and safety are substantially improved using the sensor to implement yaw control.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.150-153
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• 2000

NMR researches are required high field and high homogeneous super-conducting magnet. Thus superconducting magnets for NMR applications are designed with minimization of coil winding volume satisfied constraints such as field strength, field homogeneity, etc. In this paper, we are discussed optimal design of high field super-conducting magnet for NMR applications. For a design example, we designed unshielded superconducting magnet for 600MHz NMR spectrometer with 100mm room temperature bore size and obtained 14.1011[T] field strength and 1.33 ppm field homogeneity.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.467-469
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• 2010

We report an extremely rare case of traumatic cervical spinal subdural hematoma not related to intracranial injury. There has been no report on traumatic cervical spinal subdrual hematoma not related to intracranial injury. A 27-year-old female patient was admitted to our emergency room due to severe neck pain and right arm motor weakness after car collision. On admission, she presented with complete monoplegia and hypoesthesia of right arm. Magnetic resonance imaging (MRI) revealed subdural hematoma compressing spinal cord. Lumbar cerebrospinal fluid (CSF) analysis revealed 210,000 red blood cells/$mm^3$. She was managed conservatively by administrations of steroid pulse therapy and CSF drainage. Her muscle power of right arm improved to a Grade III 16 days after admission. Follow-up MRI taken 16th days after admission revealed almost complete resolution of the hematoma. Here, the authors report a traumatic cervical spinal SDH not associated with intracranial injury.