• Journal of Chest Surgery
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• v.22 no.1
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• pp.95-105
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• 1989

The records of 248 patients over 16 years of age who had undergone a surgical correction of a congenital cardiovascular malformation during the period of 10 years from August, 1978 to July, 1988 were reviewed. During this period, the incidence of congenital cardiovascular malformation in adult was 18.2% of 1376 total heart disease operated on and 25.5% of 986 congenital heart defects. Among them, there were 200 patients in acyanotic group and 48 patients in cyanotic group. Male versus female ratio was 1:1.28. The oldest patient was 59 years old female who had atrial septal defect. The mean age was 24.4 years old. The distribution of the lesions showed a large preponderance of atrial septal defects [37.19o] followed in frequency by ventricular septal defects [918.1%], patent ductus arteriosus [17.3%], tetralogy of Fallot [16.1%], and a variety of other complex malformations[3.2%]. In the pediatric age group, relative frequency was different from that of this adult group, showing ventricular septal defects, tetralogy of Fallot, patent ductus arteriosus and atrial septal defects in order of incidence. The hospital mortality and late mortality were 6.0% and 1.7% respectively. The causes of hospital death were low cardiac output in 10 patients, arrhythmia in 2, air embolism in 1, sepsis in 1 and respiratory failure in l. Clinical improvement upto NYHA functional class I or II postoperatively has been achieved and sustained in all patients following repair except the patients of late death and receiving reoperation. This result confirms that congenital heart defects in the adults can be corrected with a good outcome and an aggressive operative approach seems justified.

• Structural Engineering and Mechanics
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• v.91 no.1
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• pp.49-61
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• 2024

In recent decades, the majority of studies have concentrated on the utilization of Steel Square Hollow Section (SHS) columns, with minimal attention given to reinforcing columns exhibiting inherent defects. This study addresses this gap by introducing initial vertical and horizontal defects at three distinct locations (top, middle, and bottom) and employing Carbon-FRP for reinforcement. The research investigates the dimensional and positional impacts of these defects on the axial behavior of SHS columns. A total of 29 samples, comprising 17 with defects, 11 strengthened, and 1 defect-free control, underwent examination. The study employed ABAQUS modeling and conducted experimental testing. Results revealed that defects located at different positions significantly diminished the load-bearing capacity and initial performance of the steel columns. Axial loading induced local buckling and lateral rupture, particularly at the defect side, in short columns. Notably, horizontal (across the column's width) and vertical (along the column's height) defects in the middle led to the most substantial reduction in strength and load-bearing capacity. The axial compressive failure increased with the length-to-width ratio of the defect. Moreover, the application of four carbon fiber layers to strengthen the steel columns resulted in increased Energy Dissipation and a delayed onset of local buckling in the face of axial ruptures.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.597-608
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• 2011

It has been often noted as a problem that as there are no objective and clear criteria for the repair cost estimate of persistent defects, when a claim arises in relation to an apartment construction, significantly different amounts of compensation may be given for similar defects based on the experience and tendencies of the construction experts asked to make a judgment. For this reason, this research aims to present defect managers with a more reasonable and objective estimation criteria and a system to determine the repair cost of defects based on an analysis of relevant factors. The research findings show that the historical cost system is applied first, and then a standard of estimation is used to estimate the cost for the items that are not included in the historical cost system. The criteria for the repair cost for each defect is as follows: the repair cost for defects arising from a regulation violation is determined by calculating the reconstruction cost of the parts in question after demolishing them; the repair cost for progressive defects is determined based on a contribution ratio proportional to the age of the building; the repair cost for repetitive defects is calculated by considering an alternative to maximize the intended function of the defective parts; and the repair cost for value depreciation defects is determined based on the ratio of the warranty period to the lapsed years. However, repair cost estimation for dual value depreciation defects should be studied in future research.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.65-70
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• 2024

Using a computational fluid dynamics(CFD) simulation tool, we have provided a coating guideline for slot-die coating with a double layer slot die head. We have analyzed the fluid dynamics in terms of the coating speed, flow rate ratio, and viscosity ratio, which are critical for the stability of coating meniscus. We have identified the common coating defects such as break-up, air entrainment, and leakage by varying the coating speeds. The flow rate ratio is the critical parameter determining the wet film thickness of the top and bottom layers. It is shown that when the flow rate ratio exceeds or equals 1.8, air entrainment occurs due to insufficient hydraulic pressure in the bottom layer, even though the total flow rate remains constant. Furthermore, we have found that the flow of the bottom layer is significantly affected by the viscosity of top layer. The viscosity ratio of 4 or higher obstructs the flow of the bottom layer due to the increased hydraulic resistance, resulting in leakage. Finally, we have demonstrated that as the viscosity ratio increases from 0.1 to 10, the maximum coating speed rises from 0.4 mm/s to 1.6 mm/s, and the minimum wet film thickness decreases from 800 ㎛ to 200 ㎛.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.4
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• pp.499-505
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• 1998

In developing an automated surface inspect algorithm, we have designed a hierarchical classifier using neural network. The defects which exist on the surface of cold mill strip have a scattering or singular distribution. We have considered three major problems, that is preprocessing, feature extraction and defect classification. In preprocessing, Top-hit transform, adaptive thresholding, thinning and noise rejection are used Especially, Top-hit transform using local minimax operation diminishes the effect of bad lighting. In feature extraction, geometric, moment, co-occurrence matrix, and histogram ratio features are calculated. The histogram ratio feature is taken from the gray-level image. For defect classification, we suggest a hierarchical structure of which nodes are multilayer neural network classifiers. The proposed algorithm reduced error rate by comparing to one-stage structure.

• Journal of KIISE
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• v.42 no.11
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• pp.1349-1360
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• 2015

In order to improve software quality, it is necessary to efficiently and effectively remove software defects in source codes. In the development field, defects are removed according to removal ratio or severity of defects. There are several studies on the removal of defects based on software quality attributes, and several other studies have been done to improve the software quality using classification of the severity of defects, when working on projects. These studies have thus far been insufficient in terms of identifying if there exists relationships between defects or whether any type of defect is more important than others. Therefore, in this study, we collected various types of software defects, standards organization, companies, and researchers. We modeled the defects types using an ANP model, and developed the weighted severities of the defects types, with respect to the general application software, using the ANP model. When general application software is developed, we will be able to use the weight for each severity of defect type, and we expect to be able to remove defects efficiently and effectively.

• Journal of Korea Foundry Society
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• v.19 no.5
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• pp.427-432
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• 1999

Most investment castings contain some porosities and microcavities. In this study, we investigated the elimination trends of various internal defects in IN738LC investment castings for industrial gas turbine blade by hot isostatic pressing. The results showed that cylindrical defects which are under $0.6mm{\Phi}{\times}7mm$ size are mostly eliminated and aspect ratio of defects is more sensitive factor than their cross section shape in removing these defects. Increasing hot isostatic pressure and holding time doesn't affect the elimination trend of cylindrical defects over $0.6mm{\Phi}{\times}7mm$ size because first step(plastic deformation) of HIP densification doesn't occur under these HIPping conditions.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.217-226
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• 1997

This study was to develop a machine vision system to detect and to discriminate 5 kinds of apple surface defectbruise, decay. fleck, worm hole and scar. To detect the defects from an image of apple, thresholding technique was applied to images on various frames (R, G, B, H, S and I) of the color machine vision and an image of near infrared (NIR). To discriminate the detected region of defect, various features of the 5 kind defect regions were extracted from the 4 kinds of images selected above. The features were size of area, roundness, axes length ratio, mean and valiance of pixel values, standard deviation of real part of amplitude spectrum in frequency domain obtained by Fourier transform of pixel data and mean and standard deviation of power spectrum obtained by the same transform of pixel data. Routines to discriminate the defects from the features of image were developed and tested to prove their validity. The test resulted that I-frame and NIR images were the most desirable. Accuracies of the two images to discriminate the defects were noted as 76% and 77%, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.110-121
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• 2009

It is essential to embed product quality in the design process to win the global competition. Many components found in many products including automobiles and electronic devices are fabricated using sheet metal forming processes. Wrinkle and fracture are two types of defects frequently found in the sheet metal forming process. Reducing such defects is a hard problem as they are affected by many uncontrollable factors. Attempts to solve the problem based on traditional deterministic optimization theories are often led to failures. Furthermore, the wrinkle and fracture are conflicting defects in such a way that reducing one defect leads to increasing the other. Hence, it is a difficult task to reduce both of them at the same time. In this research, a new design method for reducing the rates of conflicting defects under uncontrollable factors is presented by using operating window and a sequential search procedure. A new SN ratio is proposed to overcome the problems of a traditional SN ratio used in the operating window technique. The method is applied to optimizing the robust design of a sheet metal forming process. To show the effectiveness of the proposed method, a comparison is made between the traditional and the proposed methods using simulation software, applied to a design of particular sheet metal forming process problem. The results show that the proposed method always gives a more robust design that is less sensitive to noises than the traditional method.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.207-214
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• 2005

The reflected signals from the defects of a pile and the boundaries between the pile and soils are analyzed to evaluate the integrity of drilled shafts in the impact-echo test. Signals varied according to both of the stiffness ratio of the pile to defects and that of the pile to surrounding soils. Model tests using the small size pile in the laboratory and numerical analyses have limitations in finding the characteristics of the signals due to different stress wave characteristics and unreliable modelling for the interaction between the pile and soils respectively. Full scale testing piles which have artificial defects are installed by the actual construction method and they were used to investigate the characteristics of reflected signals according to defects and the stiffness ratios of the pile to soils around.