• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1471_1472
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• 2009

In a wide variety of high-voltage applications surface flashover plays major role in the system's performance and yet has not been studied in great detail for vacuum conditions with modern diagnostic tools. surface flashover for both direct current and pulsed voltages in considered. within the setup, parameters such as geometry, material characteristics of the applied voltage can be altered. This paper review surface flashover of insulator, primarily in vacuum. It discusses theories and models relating to surface flashover and experimental results. surface flashover of insulators in vacuum generally is initiated by the emission of electrons from the cathode triple junction point (the region where the electrode, insulator, vacuum). the electrode material was copper, and a AC voltage was applied between the electrodes. these results were compared with the surface flashover characteristic of insulator at results, surface flashover influenced only insulator surface condition. and increasing vacuum pressure was risen breakdown voltage.

• Journal of Korean Neurosurgical Society
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• v.30 no.12
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• pp.1427-1429
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• 2001

Traumatic intracranial aneurysms are rare, compromising less than 1% of intracranial aneurysms. The case of 20-year-old man suffered from delayed frontal intracerebral hematoma, subarachnoid hemorrhage and intraventricular hemorrhage from traumatic pericallosal aneurysm 12 days after head injury is presented. Traumatic pericallosal artery aneurysm is always near the falcine edge, is unrelated to arterial branching point. Sudden movement of brain and artery causes vessel wall injury against the stationary edge of the falx. Because of high mortality rate of ruptured traumatic aneurysm, clinical suspicion must be focused on the prompt diagnostic work-up and early treatment.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.129-133
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• 2008

A method to reduce seam line artifact in spatial compounding of ultrasonic images is presented. Spatial compounding is a speckle reducing imaging technique in which a number of ultrasound images of a given target that have been obtained from multiple view angles are combined into a single compounded image by combining the data received from each data point in the compounded image. Since different view angle results in different view area, and the images of different view arms are combined into an image, the compounded image consists of regions with different signal to noise ratio, and the boundary lines between these regions are visible as seam lines in the compounded images. In this paper, we present an algorithm that reduces the visibility of this seam line in the spatially compounded images. Design procedure for a FIH filter is described and the results of applying the filter to in-vivo ultrasonic images are analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.224-228
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• 1997

Computer vision system become more important as the researches on inspection systems, intelligent robots , diagnostic medical systems is performed actively. In this paper, 3D measuring system is developed by using stereo vision. The relation between left image and right image is obtained by using 8 point algorithm, and fundamental matrix, epipole and 3D reconstruction algorithm are used to measure 3D dimensions. 3D measuring system was developed by Visual Basic, in which 3D coordinates would be obtained by simple mouse clicks. This software would be applied to construction area, home interior system, rapid measuring system.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.1
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• pp.19-23
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• 2018

Ultrasonography has increasingly moved from being a modality confined to the radiology department to an active diagnostic and therapeutic aid available to the head and neck at the point of patient care. However, the application of ultrasonography to the laryngeal disorder is very rare due to progressive age-related ossification of laryngeal cartilage and the presence of air in the lumen, which contribute to difficult conditions for transmission of the ultrasonic waves. The observation about the movements of larynx or surrounding structures is important to understand the physiology of phonation or swallowing and to diagnose the disease. Ultrasonography is a noninvasive and safe imaging technique that can be used to investigate the anatomic structures of the head and neck. Recently, the development of high-frequency ultrasonography makes it possible to apply the ultrasound in the evaluation of larynx.

• Journal of The Korean Astronomical Society
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• v.40 no.4
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• pp.127-129
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• 2007

It is well known that water vapor maser emission at 22.2 GHz is associated with the earliest stages of both low- and high-mass star formation and it can be considered a reliable diagnostic of their evolutionary state. Bright Rimmed Clouds (BRCs) are clouds that have been compressed by an external ionization-shock front which focuses the neutral gas into compact globules. The boundary layer between the neutral gas and the gas ionized by the incident photons is often called "bright rim" but the clumps are sometimes classified also as speck globules or cometary globules depending on their appearance. Small globules with bright rims have been considered to be potential sites of star formation and have been studied in several individual regions. We present results from high resolution VLA observations searching for new candidates of recent star formation in bright-rimmed clouds/globules associated with IRAS point sources.

• Korean Journal of Child Studies
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• v.26 no.1
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• pp.47-59
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• 2005

The Early Life Problems Scale consisting of 5-point rating for each item was prepared from the results of a questionnaire of 163 items with two sub scales constructed on the basis of Diagnostic Classification: 0-3. Respondents were 361 parents with newborn to 3-year-old children (197 boys and 164 girls). Hypothetical constructs of mental and developmental problems were identified by exploratory factor analysis. The resulting 22 factors explained 58.5% and 72.9% of the common variance for scales I and II, respectively. The rotation procedure yielded 134 items of which 118 had factor loadings of more than .30. Face validity was obtained on the basis of 18 items. The coefficients of correlation between and within factors suggest that there are interrelationships. The reliability of total scales by Cronbach's Alpha was relatively high.

• Clinical and Experimental Pediatrics
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• v.53 no.9
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• pp.824-829
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• 2010

The safety and effectiveness of colonoscopy in the investigation of lower gastrointestinal tract pathology in children has been established for more than 2 decades in Korea. The skill and experience have since advanced to the point that both diagnostic and therapeutic colonoscopy are now routinely performed by most pediatric gastroenterologists. Pediatric colonoscopy differs significantly from its adult parallels in nearly every aspect including patient and parent management and preparation, selection criteria for sedation and general anesthetic, bowel preparation, expected diagnoses, instrument selection, imperative for terminal ileal intubation, and requirement for biopsies from macroscopically normal mucosa. Investigation of inflammatory bowel disease, whether for diagnosis or follow-up evaluation, and suspected colonic polyps are the most common indication for pediatric colonoscopy. The child who presents with signs and symptoms of lower gastrointestinal disorder should undergo colonoscopy with biopsy to make the diagnosis, as well as to help determine the appropriate therapy. This review introduces practical information on pediatric colonoscopy, the author's experiences, and the role of colonoscopic examination in the diagnosis and treatment of pediatric lower gastrointestinal disorders.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.432-437
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• 1996

This paper describes a diagnostic technique of power transformers by on-line detection of ultrasonic signals. A trend of partial discharge variation in a real transformer was estimated by counting the number of ultrasonic signals until insulation paper in the point-to-plane electrode is punctured. The number of electrical signals is closely related to the ultrasonic signals generated by partial discharge. The trend of the ultrasonic signal number could easily be distinguished by taking moving average. The insulation failure due to partial discharge in transformers can be predicted based on the trend analysis of ultrasonic signal number caused by partial discharge. (author). 14 refs., 10 figs.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.195-198
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• 2001

We developed the portable blood analysis system, which can be measured pH of the blood. This system is composed to electronic circuit, mechanism, and system software. Electronic circuit is composed to the sensor, pre-amp part, temperature regulation part, fluid sensing part, A/D(analog to digital) conversion part, main and peripheral device processing part. And the mechanism is composed to the flow cell and the liquid flow part. The liquid flow part is consisted of blood and washing control system under the control of the 6-channel solenoid valve and syringe rump. The system software is composed to measurement program, calibration program, washing and diagnostic program. The program of each routine is designed as sequential process for an efficiency. And the portable pH analysis system used two-point calibration method using the two types of corrective liquid. As a result, we obtained the calibration curve and calculated the value of pH. For verifying the system, we confirmed the output voltage of the sensor, and estimated reappearance of system using the standard liquid.