• Journal of Chest Surgery
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• v.13 no.1
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• pp.34-40
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• 1980

Total 193 patients over 16 years of age who have underwent a surgical correction of congenital heart diseases during the period 1964 to September of 1979 were reviewed. 106 patients were male and 87 patients were female. 85 patients were in the ages of 16 years through 20 years. The oldest patient was 54 years old male who had atrial septal defect. The commonest defects were atrial septal defect that accounted for 66 cases [34.2%]. Ventricular septal defect was next one that accounted for 66 cases [34.2%]. Patients with tetralogy of Fallot defects were 34 cases [17.6%]. 25 cases had patent ductus arteriosus [13.0%]. Patients with pulmonary stenosis were 17 cases [8.8%] and transposition of the great arteries cases were 2 cases [1%]. There were 14 cases of operative death in this series. So operative mortality rate was 7.3%. The commonest cause of death was low output syndrome and next was renal failure. This reviewed series reveals the incidence of operable congenital heart defects appearing in adult cardiac surgical patients and an aggressive surgical approach can be justified with low operative mortality like as pediatric age group.

• Design & Manufacturing
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• v.13 no.3
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• pp.29-34
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• 2019

Cell phone injection is characterized by its small size and thinness. In addition, the product has a short cycle time, requiring a very short production schedule. To produce more accurate products faster, data from experience in producing similar products is required. In this study, two mobile phone models are presented. In this study, the quality problems caused by molding analysis and actual injection molding were analyzed and made into a database. As a result, it was considered that all the defects in the molding analysis do not affect the product in some cases, rather than appear as defects in the actual product. All defects shown in the molding analysis can be made into a database, and based on this data, it will be possible to obtain an effect that can predict more accurately whether it will cause problems after injection.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.535-544
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• 2011

The rail surface defects can cause the high impact load on the track and lead to the progress of the rail fatigue damage and the rail break. In case of the rail break, there is a great deal of risk for derailment, and thus the maintenance criteria for the rail surface defects are of great importance. In this study, using the dynamic train-track interaction analysis program, the impact wheel loads and rail bending stresses according to the depths of the surface defects have been calculated with the input data of the rail surface irregularities measured at 43 spots with surface defects in the ballasted track of high-speed railway. Considering the irregularity of track geometry, the allowable limits of wheel load and rail bending stress have been set, and the maintenance criteria for the rail surface defects was suggested by analyzing the relationship of the maximum values of wheel load and rail bending stress versus depth and width of rail surface defect. The analysis results suggest that the allowable depth of the surface defect is determined approximately 0.2mm from the limit of the impact wheel load.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.421-426
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• 2010

Purpose: Patients with serious burns are prone to chondritis due to lack of soft tissue in the auricle, which can cause severe defects in the auricular morphology. In addition, skin damage occurs frequently in the vicinity of post-burn wounds, presenting difficulties in reconstruction surgery. An auricular reconstruction has functional and cosmetic significance. The aim of this study is to develop appropriate reconstruction methods for auricular defects. Methods: Thirty seven patients, who were treated for auricular defects from 2005 to 2009, were enrolled in this study. A local flap, multiple regional flaps and cartilage framework with or without a temporal fascial flap were applied in reconstruction surgery according to the location of the auricular defect. Results: The age of the subjects ranged from 11 to 56. Some subjects had defects that cover more than half of the helical rim with most exhibiting post-burn scars in the vicinity, for whom a multiple regional flap was used. A single use of a tubed flap was sufficient for subjects with defects that covered less than half of the helical rim. A regional flap was also used for reconstruction in subjects with defects covering both the helical rim and antehelix. Conclusion: Achieving satisfactory results from the skin flaps and skin grafts for post-burn auricular defects in both functional and cosmetic aspects is a difficult task. Therefore, selecting an appropriate surgical method through proper diagnosis of the auricular defect and the state of the available skin in the vicinity is essential.

• Advances in nano research
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• v.14 no.1
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• pp.1-15
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• 2023

Driven by the scaling down of transistor node technology, graphene became of interest to many researchers following the success of its fabrication as graphene nanoribbons (GNRs). However, during the fabrication of GNRs, it is not uncommon to have defects within the GNR structures. Scaling down node technology also changes the modelling approach from the classical Boltzmann transport equation to the quantum transport theory because the quantum confinement effects become significant at sub-10 nanometer dimensions. The aim of this study is to examine the effect of Stone-Wales defects on the electronic properties of GNRs using a tight-binding model, based on Non-Equilibrium Green's Function (NEGF) via numeric computation methods using MATLAB. Armchair and zigzag edge defects are also implemented in the GNR structures to mimic the practical fabrication process. Electronic properties of pristine and defected GNRs of various lengths and widths were computed, including their band structure and density of states (DOS). The results show that Stone-Wales defects cause fluctuation in the band structure and increase the bandgap values for both armchair GNRs (AGNRs) and zigzag GNRs (ZGNRs) at every simulated width. In addition, Stone-Wales defects reduce the numerical computation DOS for both AGNRs and ZGNRs. However, when the lengths of the structures increase with fixed widths, the effect of the Stone-Wales defects become less significant.

• The KIPS Transactions:PartB
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• v.17B no.6
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• pp.445-458
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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 examination inconsistencies and industrial disasters. A shooting environment and detection algorithms are important for finding CCFL defects automatically. This paper presents CCFL defect detection algorithms using images captured under the shooting environment with sidelight which is one of the shooting environment we have suggested. The experimental result shows 4.65% of overdetection and 5.37% of unsuccessful defect detection of CCFL.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.86-91
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• 2004

It is very important to detect the bearing defects in rotating machinery since the critical failure of bearing cause a machinery shutdown. However it is difficult to detect the vibration signal resulting from the initial defects of bearing because of the high level of broadband noise. A signal processing technique, called the adaptive line enhancer(ALE) as one of adaptive filter, is studied in this work. This technique is to eliminate broadband noise without a prior knowledge of the noise and signal characteristics. Also we propose the optimal methods for selecting the three main ALE parameters such as correlation length, filter order and adaptation constant used in the adaptative process. Vibration signals for three abnormal bearings, including inner and outer raceways and ball defects, were acquired from Anderon(angular derivative of radius on)meter. The experimental results showed that the proposed technique can reliably detect the bearing defective signals masked by broadband noise.

• Journal of Sensor Science and Technology
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• v.24 no.3
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• pp.169-174
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• 2015

In this study, we developed a system to detect the various defects in the metallic objects using the phenomenon that the defects cause the changes of the natural resonant frequencies. Our system consists of a FFT Amp, an Auto Impact Hammer, a Hammer controller and a PC. Auto Impact Hammer creates vibrations in the metallic objects when tapped on the surface. These vibrational signals are converted to the voltage signals by an acceleration sensor attached to the metallic part surface. These analog voltage signals were fed into an ADC (analog-digital converter) and an FFT (fast fourier transform) conversion in the FFT Amp to obtain the digital data in the frequency domain. Labview graphical program was used to process the digital data from th FFT amp to display the spectrum. We compared those spectra with the standard spectrum to find the shifts in the resonant frequencies of the metal parts, and thus detecting the defects. We used PCB's acceleration sensor and TI's TMS320F28335 DSP (digital signal processor) to obtain the resolution of 2.93 Hz and to analyze the frequencies up to 44 kHz.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.272-279
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• 2008

The importance of maintenance of rail surface defects is increasing more according to the KTX operation. That is because during high speed operation of rolling stock, rail surface defects may cause shortened fatigue life of rail, acceleration of track degradation and reduced ride comfort. The paper was intended to study the establishment of rail grinding criteria of high-speed railway lines considering the KTX operation circumstances. For this, the specimens of UIC 60 rail on Kyeong-Bu high-speed operation lines were collected and they were tested for metallographic structure and measured for the hardness. As the factors affecting RCF causing the defects of rail surface, passing tonnage, running speed and track condition are considered.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2678-2685
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• 2020

The pipe bends and elbows in nuclear power plants (NPPs) are vulnerable to degradation mechanisms and can cause wall-thinning defects. As it is difficult to detect both the defects generated inside the wall-thinned pipes and the preliminary signs, the wall-thinning defects should be accurately estimated to maintain the integrity of NPPs. This paper proposes a deep fuzzy neural network (DFNN) method and estimates the collapse moment of wall-thinned pipe bends and elbows. The proposed model has a simplified structure in which the fuzzy neural network module is repeatedly connected, and it is optimized using the least squares method and genetic algorithm. Numerical data obtained through simulations on the pipe bends and elbows with extrados, intrados, and crown defects were applied to the DFNN model to estimate the collapse moment. The acquired databases were divided into training, optimization, and test datasets and used to train and verify the estimation model. Consequently, the relative root mean square (RMS) errors of the estimated collapse moment at all the defect locations were within 0.25% for the test data. Such a low RMS error indicates that the DFNN model is accurate in estimating the collapse moment for wall-thinned pipe bends and elbows.