• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.513-518
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• 2019

The non-destructive testing equipment using an eddy current was developed to check for defect in the vehicle transmission component. A defect master sample was made to test all types of defects that occur in the component and also an eddy current detector was manufactured and used to test and detect all kinds of defects. In addition, testing was held against the actual defective items to investigate the cause and type of defects, and a comparative study was conducted based on results from the examination. The software system of the eddy current detector was developed so that even a non-specialist can make assessment of detect in the component from the test results displayed on the monitor.

• Advances in nano research
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• v.7 no.1
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• pp.13-24
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• 2019

Well-crystalline $SnO_2$ nanoparticles of 4-5 nm size with different In contents were synthesized by hydrothermal process at relatively low temperature and characterized by transmission electron microscopy (TEM), microRaman spectroscopy and photoluminescence (PL) spectroscopy. Indium incorporation in $SnO_2$ lattice is seen to cause a lattice expansion, increasing the average size of the nanoparticles. The fundamental phonon vibration modes of $SnO_2$ lattice suffer a broadening, and surface modes associated to particle size shift gradually with the increase of In content. Incorporation of In drastically enhances the PL emission of $SnO_2$ nanoparticles associated to deep electronic defect levels. Although In incorporation reduces the band gap energy of $SnO_2$ crystallites only marginally, it affects drastically their dye degradation behaviors under UV illumination. While the UV degradation of methylene blue (MB) by undoped $SnO_2$ nanoparticles occurs through the production of intermediate byproducts such as azure A, azure B, and azure C, direct mineralization of MB takes place for In-doped $SnO_2$ nanoparticles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.30-33
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• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectrics, which can apply to employed in integrated circuits for sub-micron technology. Despite the increased use of CMP process, it is difficult to accomplish the global planarization of free-defects in inter-level dielectrics (ILD). Especially, defects like micro-scratch lead to severe circuit failure, and affects yield. CMP slurries can contain particles exceeding $1{\mu}m$ size, which could cause micro-scratch on the wafer surface. The large particles in these slurries may be caused by particle agglomeration in slurry supply line. To reduce these defects, slurry filtration method has been recommended in oxide CMP. In this work, we have studied the effects of filtration and the defect trend as a function of polished wafer count using various filters in inter-metal dielectric(IMD)-CMP. The filter installation in CMP polisher could reduce defect after IMD-CMP. As a result of micro-scratches formation, it shows that slurry filter plays an important role in determining consumable pad lifetime.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.283-288
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• 1998

Recurrent meningitis in children is not only a potentially life threatening condition, but often involves the child in the trauma though repeated hospital admissions and multiple invasive investigations to find the underlying causes. Symptoms and signs of CSF rhinorrhea or otorrhea are infrequent in these patients and difficult to diagnose in young children. All young children treated for meningitis should then be administered an evoked potential audiometry as a post-treatment test. If sensorineural hearing loss is identified, the clinician should be alerted to the possibility of CSF leakage as the cause of the meningitis. Radiologic studies should be performed to rule out preexisting congenital, or acquired, abnormalities requiring surgical exploration. Two young children with recurrent meningitis due to a right cochlear aplasia and a cribriform plate defect caused by trauma are presented to illustrate the problems of diagnosis and management. A review of literatures will also be presented briefly.

• International Journal of Railway
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• v.1 no.1
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• pp.1-5
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• 2008

The railway system requires safety and reliability of service of all railway vehicles. Suitable technical systems and working methods adapted to it, which meet the requirements on safety and good order of traffic, should be maintained. For detection of defects, non-destructive testing methods-which should be quick, reliable and cost-effective - are most often used. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to detect a crack initiation clearly with ultrasonic testing due to noise echoes. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in railway wheelset.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1940-1945
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• 2007

The wheelsets are one of most important component: damages in wheel tread and press fitted axle are a significant cost for railway industry. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to use this method because of its high viscosity and because its sensitivity is affected by temperature. Also, due to noise echoes it is difficult to detect defects initiation clearly with ultrasonic testing. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in the tread of railway wheelset.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.523-530
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• 2008

There are many defects that cause the process improvement of lifecycle problems during software development. This paper propose the management method of risk items that removes and manages the lifecycle problems as well. For the similar projects, we can estimate defects and prepare to solve them by using domain expert knowledge and the state analysis of defect items, which can greatly improve the software process. This research provides solution of management of risk items problem and detection of defect transition and its prevention and causes that happen on software development. Also, In this paper propose to making quantity of degree and transition phase.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.2
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• pp.69-81
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• 2010

A Cold Cathode Fluorescent Lamp(CCFL) is used as a LCD Monitor's backlight widely. The most common way to check CCFL's defects is an examination with the naked eye. This naked eye examination can cause an examination inconsistency and an industrial disaster. To examine CCFL defects, a shooting equipment and a defect detection algorithm are necessary. This paper shows the shooting environments for checking CCFL and presents some CCFL defect detection algorithms. As a result of experiments, our implementations showed 98.32% of successful defect detection of CCFL.

• Advances in pediatric surgery
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• v.2 no.2
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• pp.148-150
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• 1996

Transmesenteric hernia, a type of internal hernias, is a rare cause of intestinal obstruction. This intraperitoneal hernia has no sac and is formed by protrusion of a loop of bowel through an aperture in the mesentery. Incarceration leads to intestinal obstruction and subsequently, strangulation and gangrene of varing lengths of intestine. This is a case report of 4-year-old girl with transmesenteric herniation of the terminal ileum through a defect in its own mesentery. Strangulation of the affected bowel necessitates resection and primary anastomosis with repair of mesenteric defect. The postoperative course was uneventful. Acute intestinal obstruction in the absence of an external hernia and with no history of a previous surgical procedure suggests the possibility of an internal hernia, especially if the patient has a history of chronic intermittent abdominal distress.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.294-297
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• 2010

Abnormalities of the posterior arch, including congenitally absent cervical pedicle and cervical spondylolysis, are rare entities that are usually found incidentally on neck radiographs. It is important to recognize these characteristic radiological features because their radiographic appearance may cause them to be confused with more serious entities such as fractures, locked facets, and tumor-induced bony erosions. Also, it is important to distinguish these abnormalities from similar pathologies to prevent the use of inappropriate treatment We report the relevant clinical and radiological findings seen in three cases of posterior arch defect after trauma with review of pertinent literature.