• Fire Science and Engineering
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• v.29 no.3
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• pp.59-64
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• 2015

This study analyzed results of the causes of failure in 1,022 fire trucks currently being used in South Korea (aerial ladder, aerial platform, pumper, and chemical fire trucks). The results show that 46% of aerial ladder trucks have defective in the elevator brake systems, 29% of aerial platform trucks have contamination in the hydraulic oil, 37% of pumpers have defective in the pneumatic cylinders of the air supply system, and 39% of chemical fire trucks have defective in the powder fire extinguishing systems. The principal reasons for malfunctions are deterioration of the apparatuses, and accumulated fatigue from repetitive use of certain components, such as pneumatic cylinders in the air supply system and wire rope jamming in rollers in the ladder apparatus. These manufacturing defects should be improved upon in the manufacturing process. As a result, the fire trucks, which are used for 5 years or more, need precise inspections in accordance with the Regulation on Fire Apparatus Maintenance. Fire apparatuses have a service life of 10 to 12 years or more. They need to be replaced or require life extension, and they should be kept in top shape with the best maintenance for public safety.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.250-256
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• 2013

It is described that the proton beam induces micro-size defects and electronic deep levels in luminescence Thin Film. Coincidence Doppler Broadening Positron Annihilation Spectroscopy (CDBPAS) and Positron lifetime Spectroscopy were applied to study of characteristics of a poly crystal samples. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S-parameter value. The samples were exposed by 3.0 MeV proton beams with the intensities ranging between 0 to ${\sim}10^{14}$ particles. The S-parameter values decreased as increased the proton beam, that indicates the protons trapped in vacancies. Lifetime ${\tau}_1$ shows that positrons are trapped in mono vacancies. Lifetime ${\tau}_2$ is not changed according to proton irradiation that indicate the cluster vacancies of the grain structure.

• The KIPS Transactions:PartA
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• v.15A no.3
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• pp.141-149
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• 2008

In this research we present a novel method which combines and visualizes the design model and the FDM-based simulation result of solidification. Moreover we employ VR displays and visualize stereoscopic images to provide an effective analysis environment. First we reconstruct the solidification simulation result to a rectangular mesh model using a conventional simulation software. Then each point color of the reconstructed model represents a temperature value of its position. Next we map the two models by finding the nearest point of the reconstructed model for each point of the design model and then assign the point color of the design model as that of the reconstructed model. Before this mapping we apply mesh subdivision because the design model is composed of minimum number of points and that makes the point distribution of the design model not uniform compared with the reconstructed model. In this process the original shape is preserved in the manner that points are added to the mesh edge which length is longer than a predefined threshold value. The implemented system visualizes the solidification simulation data on the design model, which allows the user to understand the object geometry precisely. The immersive and realistic working environment constructed with use of VR display can support the user to discover the defect occurrence faster and more effectively.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.521-526
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• 2008

Purpose: Most burn scar contractures are curable with skin grafts, but free flaps may be needed in some cases. Due to the adjacent tissue scarring, local flap is rarely used, and thus we may consider free flap which gives us more options than local flap. However, inappropriate performance of free flap may lead to unsatisfactory results despite technical complexity and enormous amount of effort. The author will discuss the points we should consider when using free flaps in treating burn scar contractures Methods: We surveyed patients who underwent free flaps to correct burn scar contractures from 2000 to 2007. We divided patients into two groups. The first group was those in which free flaps were inevitable due to exposure of deep structures such as bones and tendons. The second group was those in which free flap was used to minimize scar contracture and to achieve aesthetic result. Results: We performed 44 free flap on 42 patients. All of the flaps were taken well except one case of partial necrosis and wound dehiscence. Forearm free flap was the most common with 21 cases. Most of the cases(28 cases) in which free flaps were inevitable were on the wrist and lower limbs. These were cases of soft tissue defect due to wide and extensive burns. Free flaps were done in 16 cases to minimize scar contracture and to obtain aesthetic outcome, recipient sites were mostly face and upper extremities. Conclusion: When using free flaps for correction of burn scar contractures, proper release and full resurfacing of the contracture should be carried out in advance. If inadequate free flap is performed, secondary correction is more challenging than in skin grafts. In order to optimize the result of reconstruction, flap thickness, size and scar of the recipient site should be considered, then we can achieve natural shape, and minimize additional correction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.102-107
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• 2003

At orthodontic treatment, we have made every effort to get rigid anchorage which is not stirred when teeth move. As a result, the miniscrew that is rigid anchorage was invented recently, and now it is used widely. Concerning the advantage of miniscrew, it is reduced dependence of extraoral anchorage and it shortens treatment time for rapid tooth movement. In contrast, the defect of miniscrew is falling off it resulted from increasing of the mobility. So the purpose of this research is to be of help to prognose clinical use of miniscrew, which is inserted for intraoral anchorage, by investigating and comparing the failure rate of miniscrew for loading time. This study researches the failure rate of miniscrew for teeth movement at the orthodontic treatment. The failure rate of miniscrew in mid course, after inserting 147 miniscrews in 51 patients, is 13%(20/147). It showed no statistically significant differences as compared man with woman, maxilla with mandible, double-head with uni-head miniscrew, and drilling and non-drilling before inserting the miniscrew. In comparison below twenties with over twenties and the times that we give load to miniscrew, it produced that the failure rate of miniscrew is 9.7% higher in the case of below the twenties than over the twenties. Also, the failure rate of loading immediately is 10.8% higher than loading after 7 days. According to using driver for the insertion of miniscrew, the failure rate of miniscrew is higher in the case of using machined driver than in the case of using hand driver when the level of significance is 95%. According to the research, we can suppose that the failure rate has no concern with using miniscrew on man or woman, maxilla or mandible, the shape of head, and drilling or non-drilling before insertion of miniscrew. Therefore, we can choose eclectic miniscrew as demands. In addition, we must notify the patient, below twenties, to be possibility of high failure rate. And It is strongly recommended to give load after $1{\sim}2$ weeks for healing of the insertion area.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.45-50
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• 2001

Open rack vaporizer (ORV) has been used in liquefied natural gas (LNG) receiving terminal in order to vaporize LNG into natural gas (NG) by heat exchange with seawater The U-type ORV which had been operated with seawater for 14 years is one of the important utilities of the gas production and the weld part of tube connected with header_ pipe had experienced many corrosion problems. To elucidate the cause of corrosion at weld part of vaporizer tube, corrosion potentials were compared by parts. This study concerns on the measurement of corrosion pit depth using non-destructive method and the evaluation of stress distribution in an aspect of safety with finite element analysis. In order to confirm the reliability of galvanic corrosion between weld parts and base metal, the measurement of corrosion potential by parts was conducted for 20 minutes in 3.5$\%$(wt.) NaCl solution. Many non-destructive methods were tried to measure the remaining thickness of vaporizer tube at fields. For general corrosion, tangential radiography test was confirmed as an effective method. In case of a fine corrosion pit, the shape of corrosion pit was reproduced using surface replication method. From collected data, stress distributions were quantitatively evaluated with 2-dimensional finite element method and the diagnostic evaluation on internal pressure of the U-type vaporizer could be made.

• Journal of Society of Preventive Korean Medicine
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• v.7 no.2
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• pp.121-130
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• 2003

The Musculoskeletal Disease has been ignored or turned away due to the difficulty of diagnosis and the vagueness of judgement up to now. Contrary to other diseases, there were many cases where the character of the Musculoskeletal Disease wasn't revealed through the objective inspection. And that's because the Musculoskeletal Disease appears for the most part due to muscular defect so it is impossible to diagnose the muscle by X-ray diagnosing the bone and it is also impossible to diagnose the fine damage of the muscle or tendon even by advanced device like MRI. As the nervous blood vessels or acupunctures pass through or are next to the muscle, the tension of the muscle put pressure on these so can become the direct or indirect causes of various kinds of pains or intern diseases. But in spite of that, for lack of proper equipment diagnosing the state of the muscle(Shortened.. Relaxed... or Hardened...) the muscle has been disregarded or neglected intentionally or unintentionally. While many people think themselves to be a muscular expert, if they don't see the shape of the muscle, that is just like blind treatment. But as now the equipment diagnosing the state of the muscle is developed, it seems that this problem can be settled. It was attempted in this study that the muscle or skeleton of the Musculoskeletal disease patients was diagno the treatment order and method were decided by a questionnaire survey and simple inspection, and the Musculoskeletal correction exercise using the muscle management and sling system made them escape from the Musculoskeletal disease, turning their muscle into more flexible and stronger muscle. As a result notwithstanding the limited treatment period '12 times', the improvement rate was as high as 74%, which showed that the muscle management and Musculoskeletal correction exercise had a great effect on the symptom improvement of the patients. If the treatment times had increased, the improvement rate also would have increased more.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.564-568
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• 1996

Pseudoaneurysm of the ascending aorta following cardiac surgery is very unusual and it is poten- tially fatal. We report here a fourteen year-old female patient with pseudoaneurysm of the ascending aorta following a repair of a congenital ventricular septal defect at other hospital 50 months ago. Although she had a mild superficial wound infection postoperatively, she enjoyed uneventful. life until she visited our hospital for a generalized weakness and exertional dyspnea which developed a month ago. Chest CT and echocardiogram showed partially calcified pseudoaneurysm of the ascending aorta. Two aortic defects were located on the anterolateral ascending aortic wall wkere it was suspected as a previous sites of aortic and cardioplegic cannulation. The internal wall of the pseudoaneurysm was covered with neoendothelium and intervened by septal tissue. Two defects on he aortic wall were oval in shape and about 1.5cm in the greatest diameter The defects were trimmed to make a one large de- fect and it was reconstructed with patch designed from 22mm collagen impregnated double velour Dacron graft. The postoperative course was uneventful.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.636-643
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• 1999

Ectodermal dysplasia is a genetic birth defect in which at least abnormally develop two structures derived from the ectoderm. It is usually inherited in autosomal dominant or autosomal recessive pattern. Oral manifestations are oligodontia, anodontia, dysmorphic teeth(conical shape), decreased occlusal vertical dimension and alveolar bone. Extraoral signs may include decreased or absent sweat glands, sparse and fine hair, saddle nose, hearing loss and decreased production of body fluids including saliva. Most affected children require extensive dental treatment to restore their appearance and help the development of a positive self image. The patient's overclosed profile was due to a decreased vertical dimension. The use of overdenture is to preserve erupted teeth, to accomodate the newly constructed occlusal plane, to improve retention and stability of denture and to maintain the remaining alveolar bone. The restoration of vertical dimension improved the child's speech, swallowing, and eating. Growth continue until the age of approximately 18. As child grows, replacement dentures will have to be fabricated primarily to accomodate increasing vertical dimension and changing dentition. Implants may be indicated later if the alveolar bone is adequate. Periodic recall visits are advised, to monitor the dentures during periods of growth and development, and eruption of the permanent teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.662-669
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• 2005

Nuclear factor I (NFI) exists in the odontoblast and osteoblast. NFI-C null mice demonstrated aberrant odontoblast differentiation, abnormal dentin formation, and molar lacking roots. The purpose of this study was to examine phenotype of the aberrant odontoblast in NFI-C null mice and to evaluate the expression of DSPP and BSP mRNAs in NFI-C null mice with in-situ hybridization. The results were as follows: 1. In the NFI-C (-/-) mice, the crown dentin of molar showed normally formation, but there was no root dentin. 2. In the NFI-C (-/-) mice, the labial dentin of mandibular incisors showed relatively a lot of dentin formation, but the lingual dentin showed defect. 3. In the NFI-C (-/-) mice, the odontoblast of mandibular incisors revealed abnormal shape and trapped in osteodentin-like mineralized tissue. 4. In the NFI-C (-/-) mice, the odontoblast in the crown dentin of molars showed strong expression of DSPP, the odontoblast in the root dentin of molars was not expression of DSPP. In the NFI-C (-/-) mice the odontoblast in the mandibular incisors showed weekly expression of DSPP 5. In the wild mice, the odontoblasts of mandibular incisors were not expression of BSP, but in the NFI-C (-/ -) mice the odontoblast of mandibular incisors showed strong expression of BSP These results suggest that odontoblast in the NFI-C (-/-) mice changes the phenotype into osteoblast.