• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.57-63
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• 2015

The incidence of fires caused by electrical factors has increased with the growth in domestic electrical consumption. According to the national fire data system of national emergency management agency, electrical fires accounted for 20% of all domestic fires in the last 10 years. Electrical fires are mainly caused by short circuit, leakage current, defect in an electrical equipment, over load, utility fault, etc. The fault current can be several times larger than the nominal current, thereby exceeding the rated current of cable. Consequently, the cable conductor, typically copper wire, heats up to a temperature that ignites surrounding combustibles. This paper describes the transient characteristics of the 0.6/1kV, TFR-8 cable have been investigated, and analyzed under the over current conditions for reduce the risk of electrical fire by experimental and FEM analysis. The experimental and FEM(Finite Element Method) analysis results of temperature and resistance variation according to the over current in copper wires were analyzed. The experimental results coincide well with the FEM analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.36-43
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• 2016

Carbon fiber-reinforced silicon carbide (Cf-SiC) and SiC / SiC composites have high thermal conductivity, and excellent corrosion and wear resistance, a low coefficient for thermal expansion and are lightweight. This is why they are commonly used in parts of the aerospace industry to develop an aircraft thrust deflector, jet vane, combustion chamber, elevens, body flap, and a shingle. So, understanding how this state-of-the-art Cf-SiC affects both internal and external crack detection and determining issues during the manufacturing process of composite materials, should be evaluated according to valuation techniques in the external environment. In this paper, we apply a non-contact air ultrasonic technique of non-destructive testing techniques to perform a study on internal defect detection identification and assessment of carbon-fiber reinforced silicon carbide composites to perform basic research and applied research.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.683-686
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• 2003

Isolated right ventricular hypoplasia is a rare clinical entity. We describe a case of right ventricular hypoplasia, single atrium and spongy myocardium of left ventricle. The volume of right ventricle was half the volume of left ventricle and z-value of tricuspid valve was -4 preoperatively The patient, 6-year-old boy, underwent atrial partitioning with 3 mm fenestration, Postoperative course was smooth and he tolerated the biventricular state well during follow-up. Follow-up catherterization was done 27 months later The tricuspid valve grew well (z-value= -0.4) and atrial septal fenestration is closed spontaneously. This article reports a case of successful biventricular repair in a patient with isolated right ventricular hypoplasia.

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.207-212
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• 2014

Aluminum-doped zinc oxide (AZO) films were deposited on SiOC/Si wafer by an RF-magnetron sputtering system, by varying the deposition parameters of radio frequency power from 50 to 200 W. To assess the correlation of the optical properties between the substrate and AZO thin film, photoluminescence was measured, and the origin of deep level emission of AZO thin films grown on SiOC/Si wafer was studied. AZO formed on SiOC/Si substrates exhibited ultraviolet emission due to exciton recombination, and the visible emission was associated with intrinsic and extrinsic defects. For the AZO thin film deposited on SiOC at low RF-power, the deep level emission near the UV region is attributed to an increase of the variations of defects related to the AZO and SiOC layers. The applied RF-power influenced an energy gap of localized trap state produced from the defects, and the gap increased at low RF power due to the formation of new defects across the AZO layer caused by lattice mismatch of the AZO and SiOC films. The optical properties of AZO films on amorphous SiOC compared with those of AZO film on Si were considerably improved by reducing the roughness of the surface with low surface ionization energy, and by solving the problem of structural mismatch with the AZO film and Si wafer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1780-1785
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• 2016

This paper presents few case studies of state diagnosis of XLPE cables using very low frequency techniques. The power cables of 22.9kV which have installation fault were assessed using VLF technique in addition to other techniques like insulation resistance and DC voltage withstand test. From the experimental results, The dielectric loss($tan{\delta}$) values of degradation of the cable(joint, knife, needle) at $U_0$ were 5.839, 5.526 and 6.251, respectively and all values were "further study advised". VLF PD measurement was also found defective portion. These method was effective in defect to fault in the degradation of the cable. However, the breakdown did not occur in the degradation of the cable because of properties of XLPE insulation. Few case studies of using VLF $tan{\delta}$ diagnosis for fault are measured and analyzed. The $tan{\delta}$ values at $U_0$ were "further study advised" or "action required".

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.264-266
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• 2012

Injury to the bilateral internal branch of superior laryngeal nerve (ibSLN) brings on an impairment of the laryngeal cough reflex that could potentially result in aspiration pneumonia and other respiratory illnesses. We describe a patient with traumatic cervical injury who underwent bilateral ibSLN palsy after anterior cervical discectomy with fusion (ACDF). An 75-year-old man visited with cervical spine fracture and he underwent ACDF through a right side approach. During the post-operative days, he complained of high pitched tone defect, and occasional coughing during meals. With a suspicion of SLN injury and for the work up for the cause of aspiration, we performed several studies. According to the study results, he was diagnosed as right SLN and left ibSLN palsy. We managed him for protecting from silent aspiration. Swallowing study was repeated and no evidence of aspiration was found. The patient was discharged with incomplete recovery of a high pitched tone and improved state of neurologic status. The SLN is an important structure; therefore, spine surgeons need to be concerned and be cautious about SLN injury during high cervical neck dissection, especially around the level of C3-C4 and a suspicious condition of a contralateral nerve injury.

• Journal of Korean Neurosurgical Society
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• v.51 no.3
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• pp.141-143
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• 2012

The authors describe a case of choriocarcinoma that metastasized to the cerebral cortex, vertebral body, and intramedullary spinal cord. A 21-year-old woman presented with sudden headache, vomiting and a visual field defect. Brain computed tomography and magnetic resonance examinations revealed an intracranial hemorrhage in the left temporo-parietal lobe and two enhancing nodules in the left temporal and right frontal lobe. After several days, the size of the hemorrhage increased, and a new hemorrhage was identified in the right frontal lobe. The hematoma and enhancing mass in the left temporo-parietal lobe were surgically removed. Choriocarcinoma was diagnosed after histological examination. At 6 days after the operation, her consciousness had worsened and she was in a state of stupor. The size of the hematoma in the right frontal lobe was enlarged. We performed an emergency operation to remove the hematoma and enhancing mass. Her mental status recovered slowly. Two months thereafter, she complained of paraplegia with sensory loss below the nipples. Whole spine magnetic resonance imaging revealed a well-enhancing mass in the thoracic intramedullary spinal cord and L2 vertebral body. Despite chemotherapy and radiotherapy, the patient died 13 months after the diagnosis.

• Tribology and Lubricants
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• v.33 no.4
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• pp.168-186
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• 2017

This paper presents a wear analysis procedure for calculating the wear of journal bearings during the start-up and coast-down cycles of a motoring stripped-down single cylinder engine operating with a tilted shaft. In order to decide whether the lubrication state of a journal bearing is in the mixed-elasto-hydrodynamic lubrication regime, we utilize lift-off speed and MOFT (most oil film thickness) under mixed-elasto-hydrodynamic lubrication regime at the corresponding aligned shaft. We formulate an equation for the modified film thickness in a misaligned journal bearing considering the additional wear volume described in Part I of this study. For this, we use the calculation results of the degree of misalignment and tilting angle obtained after finding the eccentricities of the two bearings supporting the crankshaft of a single cylinder engine. In this Part II, we calculate the wear of journal bearings using the fractional film defect coefficient, the asperity load sharing factor, and the modified specific wear rate for the application of mixed-elasto-hydrodynamic lubrication regime. We show that the accumulated wear volume after turning the ignition switch on and off once, increases to ${\sigma}=39{\mu}m$ and then decreases from ${\sigma}=39{\mu}m$ with increasing in surface roughness.

• Korean Journal of Psychosomatic Medicine
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• v.4 no.1
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• pp.91-97
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• 1996

Lithium is a widely used important drug in the treatment of manic-depressive illness and its prevention of relapse. However, this drug has a Low therapeutic index, therefore, it has many attendant side effects. The most prevalent renal effect of lithium is impairment of concentrating ability and this defect appeared into overt polyuria. A renal lesion is confined to the collecting tubule and 12-20% of patients taking lithium suffer from nephrogenic diabetes insipidus. This nephrogenic diabetes insipidus causes the states of extracellular fluid depletion, hypernatremia and precipitates lithium intoxication. In such situation, symptoms of nephrogenic diabetes insipidus and lithium intoxication are very similar, so we should be very cautious to discriminate them. We herein report a patient characterized by a prolonged stuporous state, hypernatremia and severe nephrogenic diabetes insipidus during lithium therapy.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.628-634
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• 2018

In an examination of the temporomandibular joint disc, MRI(Magnetic Resonance Imaging) is a useful method, and it is necessary to conduct an examination with one's mouth open for a long time to observe the accurate position change of the disc. Thus, this study would produce a TMJ device, using the 3-D printing technology, which would maintain the state of opening the mouth and would evaluate its usefulness as compared to the existing fixed device. As compared to the image using the existing TMJ device, the image taken with the self-produced TMJ device with a 3-D printer showed a somewhat lower SNR, but there was no defect for a clinical use. It is judged that benefits to costs would increase, since it can be customized for the individual patient and can contribute to the production of similar tools by utilizing the 3-D printing technology.