• Tribology and Lubricants
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• v.32 no.4
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• pp.113-118
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• 2016

As an economic, high quality, and highly reliable gear with low noise and low vibration is demanded, an overall finite element analysis regarding a gear is required. Also, an infrared thermography test, which is a quantitative testing technique, is demanded for safety and longer lifespan of gear products. In order to manufacture a gear product or to determine safety of a gear being used, it is necessary to precisely determine ingredients of a material constituting a gear and detect any internal defect. This study aims to realize a design that minimizes the spur gear displacement with respect to power during its rotation and ensures the spur gear control capacity by using a 3D model and the midasNFX program. This facilitates the assessment of the possibility of cracking by evaluating the stress intensity and focusing on the integrity of the spur gear. We prepare the specimen of the spur gear based on the possibility of cranking as per the result of the structural interpretation from an infrared ray thermal measuring technique. After cooling the spur gear, we perform experiments using thermography and halogen lamps and analyze the temperature data according to the results of the experiment. In the experiment which we use thermography after cooling, we find a rise in the temperature of the room. As a result, the defective part show temperatures lower than their surroundings while the normal parts have temperatures higher than the defective parts. Therefore, it possible to precisely identify defective part owing to its low temperature.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.442-449
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• 1998

Freeze-dried cortical bones of the goat were transplanted to the experimental fibular defect of 10 dogs for valuating the possibility of xenogeneic bone implantation and the specificity of BM(Bone Morphogenetic Protein). The . freeze-dried cortical bone eliminated antigens and defatted with chloroform and methanol were freeze-dried at $-80{\circ}C$ for preservation of BMP and then sterilized with 50 gas and storaged in room temperature. Ten freeze-dried cortical implants of the goat were transplanted in experimentally defected regions of bilateral fibula of 5 dogs in clinically normal. The transplanted region had been radiographed for observing state of bone union and BALPOone Alkaline Phosphatase) in the serum of the host was measured for valuating activity of oteoblast per 2 week-interval after transplant procedures. New bone formation had been observed early in one of ten regions around implants about the same time as autoimplant regions. It was incorporated with its host bone during 4-12 weeks after transplantation. In another 2 cases of 2 dogs, new bone formation and absorption of implant had been observed from 4 weeks but they were not incorporated completely until 20 weeks. The rest of the freeze-dried bone implants, 7 cases of 4 dogs had not been observed new bone formation nor absorption of implants. The freeze-drying method for implants means to not influence bone incorporation. Although less of union percentages the union form of this experiment were similar to alloimplantation and it may mean to block immunity reaction that disturbs the bone induction by BMP. It demonsknted that the possibility of the xenogenous bone implantation is recognized by reason of the low specificity of BMP between goat and dog.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.165-174
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• 1997

It is not possible to define the earth's interior because of it complicity. However, it can be interpreted directly and/ or indirectly. Geophysics is the subject of this study. To study the possibility of construction supervision by geophysical method, geophysical prospecting was performed and studied at the SamYang pumping well area in Cheju Island, where, although underground dam was constructed, the saline water invade the pumping well area. This study focuses on the construction supervision by electrical measurements. Two electric resistivity survey lines are installed in the pumping well site, and at each line electric survey was conducted at ebb and flow tides. To increase the data quality SP (self-potential) survey was also performed. As a result the geophysical exploration methods explained the defect of construction well, and It shows that geophysical probe can be a useful tool for the construction supervision.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.334-339
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• 2019

In this study, the vibration test method to nondestructively evaluate the possibility of vehicle BSR (Buzz, Squeak, Rattle) noise generation in spot-welded structures was proposed. The weld quality was predicted by analyzing the local vibration transmission characteristics for the beam-shaped structure attached to testing spots. The bending stiffness was evaluated from the identified vibration properties. From the change in the stiffness, the weld quality was evaluated. For verification of the proposed method, the welded specimens were fabricated with partial changes in welding parameters. The local vibration transfers were measured. The frequency bands affected by the weld quality was identified. The capability of evaluating the welding parameters including defect position and quality variations was investigated. The proposed method enables fast quality evaluation to minimize the possibility of BSR noise generation in the manufactured vehicle.

• Journal of Genetic Medicine
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• v.20 no.1
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• pp.25-29
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• 2023

The CYP11A1 gene encodes for the cholesterol side-chain cleavage enzyme (P450scc), which initiates steroid hormone biosynthesis. Defective P450scc activity results in severe glucocorticoid and mineralocorticoid deficiencies. We describe a case of P450scc deficiency due to a novel homozygous CYP11A1 variant inherited from the mother with a possibility of uniparental disomy (UPD). The patient was a female, had no family history of endocrine disease, and showed adrenal insufficiency at 13 days of age. Hormonal analysis with an adrenocorticotropic hormone stimulation test showed both glucocorticoid and mineralocorticoid deficiencies, presumed to be a defect of the early stage of steroidogenesis. Exome sequencing reported a novel homozygous frameshift variant of CYP11A1 (c.284_285del, p.Asn95Serfs*10), which was inherited from the mother. Additionally, homozygosity in 15q22.31q26.2, which included CYP11A1, was identified using a chromosomal microarray. It was suggested that the possibility of maternal UPD was involved as the cause of a P450scc deficiency by unmasking the maternally derived affected allele. To our understanding, P450scc deficiency associated with UPD encompassing CYP11A1 had not been reported in Korea before. Genetic analysis can help diagnose rare causes of primary adrenal insufficiency, including P450scc deficiency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.253-260
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• 1996

The purpose of this investigation was to determine the possibility of clinical use of toothash-plaster block implant material with ratio of 2 : 1 by weight. We made 1cm diameter round partial thickness defect at both sides of calvaria. Right side was implanted with block and left side was not implanted as a control site. The following results were obtained : 1. In gross examinations, the implanted site had a hardness on palpation and the margin with host bone was not identified clearly at 12 weeks after operation. But control site contained the fibrous tissue. 2. In the light microscopic examinations, most of the implanted sites were repaired by newly-formed bone at 12 weeks postoperatively. 3. At 8 weeks postoperatively, the implanted particles were divided into small granules and the amount was decreased gradually. Some remained particles were united directly with newly-formed bone. But the implanted particles still remained partly at 24 weeks postoperatively.

• Composites Research
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• v.17 no.1
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• pp.1-9
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• 2004

A new non-destructive evaluation method using tapping sound is proposed. This method, named Tapping Sound Analysis, is using the difference between tapping sound data of healthy structure and defective structure as the criteria of determination of internal defect of composite structure. For the characterization of tapping sound, a feature extraction method based on wavelet packet transform is proposed. And a feature index is defined for the decision of existence of internal defects. To prove the possibility of proposed method as a non-destructive evaluation method, experimental study is performed. The tapping sound data of healthy structure and defective structure are measured and compared based on the proposed decision method. The experimental results showed that the feature index is a good indicator for the determination of internal defects.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.215-220
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• 2002

Epoxy-coated re-bar was partly used to the structures and put to practical use, but were not economical and appeared to have defects such as the diminishing of long term bond strength between concrete. The study of polymer cement slurry coated re-bar was started in order to complement the defect of epoxy coated re-bar, and ever since the basic properties appeared to be excellent. But, study of bond properties embedded in concrete specimens was insufficient until now. This study attempts to examine the possibility of improving the bond strength of polymer cement slurry coated re-bar between concrete specimens in accordance with ACI Code and KS Code through pull-out test of 150mm$\times$150mm$\times$150mm substrates with polymer cement slurry coated re-bar having polymer cement ratios of 50%, 75% and 100%, coating thickness 250${\mu}{\textrm}{m}$, 450 ${\mu}{\textrm}{m}$ and with curing ages of 3, 7 and 28 days. High strength concrete was designed having a compressive strength of 500kgf/cm2 as specified. Practical bond length ranges of 55 and 85mm were applied to each of specimen. The bond strength of polymer cement slurry coated re-bar using St/BA-1 and St/BA-2 was compared to that of plain re-bar. The results of this study showed that the bond strength of 55mm bond length was much higher than that of 85mm bond length.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.411-420
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• 1996

The structure of the scale formed on the surface of Fe - Cr - X alloys exposed to 1143K high sulfidation($Ps_2$ = 1.11$\times$$10^-7$ atm, $Po_2$ = 3.11$\times$$10^-20$ atm) or sulfidation/oxidation(($Ps_2$= 1.06$\times$$10^-7$ atm, ($Po_2$ = 3.11$\times$$10^-18$ atm) environment has been observed and analysed using XRD, SEM/EDS. To investigate the possibility of protective film formed on the surface of the alloys, Aluminium, Nickel were selected as alloying elements. Thermodynamic phase stability diagram was used to predict the reaction path of scale formed on Fe - Cr - X alloys. Parabolic rate constant($K_p$) value with 6wt% Al in Fe - 25Cr alloy decreased significantly compared with the Fe - 25Cr alloy without 6wt% Al. Since thin layer of defect free sulfide film, (Al, Cr)Sx, was formed at the alloy/scale interface. Fe - rich sulfide scale at outer layer and Cr - rich sulfide scale containing porosity at inner layer of Fe - 25Cr alloy have been observed. The reaction path for these scales could be predicted by the thermodynamic stability diagram.