• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.691-696
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• 2015

The interest in software defects is growing. Companies are working on reducing them by various ways with a software development part, customer service part and quality management part. The defect data collected from them will be analyzed according to the condition and purpose to minimize the defect, and it will contribute to improving the quality of products. This study analyzed the software defect progress for companies based on the test maturity model, and set up the defect preventing process. They were applied to the project, and the number of defects decreased from 106 to 16. This study focused on the existing defect, which is a basic requirement for software quality management, and have importance by presenting a way to improve the software product quality with minimum resources.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.922-934
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• 2014

In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2977-2983
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• 2023

During normal operation, some parts of the fission product in the defective fuel rods can release into the primary loops in PWR and the escape rate coefficients are widely used to assess quantitatively the release behaviors of fission products in the industry. The escape rate coefficients have been standardized and have been validated by some drilling experiments before the 1970s. In the paper, the model to determine the escape rate coefficients of fission products has been established and the typical escape rate coefficients of noble gas and iodine have been deduced based on the measured radiochemical data in one operating PWR. The result shows that the apparent escape rate coefficients vary with the release-to-birth and decay constants for different fission products of the same element. In addition, it is found that the escape rate coefficients from the defective rod with large defects are much higher than the standard escape rate coefficients, i.e., averagely 4.4 times and 1.8 times for noble gas and iodine respectively. The enhanced release of fission products from the severe secondary hydriding of several defective fuel rods in one cycle may lead to the potential risk of the temporary shutdown of the operating reactors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3416-3422
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• 2014

A shock absorber rod is located in the center of the absorber piston and is responsible for the reciprocating movement portion. If it has surface defects, the damping performance of product will be adversely affected. A rod surface has gloss by heat treatment. Therefore, it is difficult to find a defect, such as dust, imprints, and blowholes. Because a total inspection is achieved by visual inspection by workers, it causes eyestrain and the quality of the product is not constant. In this paper, a machine vision system was developed to find a defect using a line-scan camera. The machine can detect surface defects than 0.3mm. To minimize the occurrence probability of defects on the inspection process, the developed auto inspection system had an automatic feeding system and incorporated a protection system. Through the development of this system, which relies on the operator's visual inspection of the surface of the shock absorber, the Rod inspection system constructed quality inspection standards and standardized tests to ensure improved reliability.

• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.327-340
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• 2015

Purpose : Recently, many quality issues are aroused in military forces, such as failures in K-series weapons, combat uniforms' defects and 40mm ammunition explosion accident. To address these problems, Defense Agency for Technology and Quality(DTaQ) introduced new systems such as Manufacturing Readiness Assessment(MRA), Test Report Information System(TRIS) and so on. However, these activities require the human and time resources which cannot be increased in short period. In this paper, we suggest more practical and efficient product examination method. Methods : The most popular and widely used government's quality assurance technique is a sampling method to examine the product. In this research, we first reviewed the DTaQ's quality assurance regulation, then identified several possible problems and finally suggested more efficient and effective sampling plans. Results : We have suggested new sampling framework and evaluated its performance on two military supplies by comparing with other sampling method, and observed that the number of tested samples can be substantially reduced. Therefore, required quality assurance time can be saved. Conclusion : In this paper, we first reviewed the product examination frameworks of DTaQ, PPQMS and DCMA. Then we identified several possible problems which can cause the loss of objectivity and time. To handle these problems, we suggested the new product examination framework and tested the framework to verify the performance.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.1
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• pp.151-180
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• 2015

South Korea is advancing the unmanned aircraft private commercial business. Unmanned aerial vehciles industry has been developing for several years also abroad. However, unmanned aerial vehciles industry, can be an accident occurs. Accident of unmanned aerial vehciles to occur material damage and casualties. Particularly if an accident because of a defect in the unmanned aerial vehciles has occurred, it is necessary to analyze the liability for this. The defect accidents unmanned aerial vehciles has been the different manufacturing and design product is intended, whether it is important how to prove to this. This is because, unmanned aerial vehciles are designed in any intent of the original, it is impossible to victims know. So imposing a responsibility to prove the design by the manufacturer intended consumer is not fair. Moreover, the consumer, it is necessary to prove only that the product is one that normally dangerous lacked safety can be expected. This is a detailed issue of judgment of defects of unmanned aerial vehciles, the manufacturer to bear the accountability. In the case where the defect on the display of the unmanned aircraft is a problem, and if it reasonable indication, it is not appropriate to be required to prove that it was possible to prevent damage to the victim.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.3
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• pp.1-6
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• 2006

In this paper, we described the existing methodology of product safety analysis and proposed a Petri-nets based method to analyze product safety systematically. The proposed method can be used to find the defects of hardware/software and the error of human behavior. We also discussed the differences between the Fault Tree Analysis and Petri-nets based method by giving an example.

• Transactions of Materials Processing
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• v.8 no.5
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• pp.437-448
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• 1999

The reheating of the billet in the semi-solid state as quickly and homogeneously as possible is one of the most imposrtant parts. To obtain a fine globular microstructure in cross section of billet, the optimal design of the induction coil for variation of alloys and specimen sizes is necessary. For the thixo-forging process the construction of the reheating data base is very important, because the reheating conditions are different for variation of SSM and billet sizes. So in this study, the optimal coil design of A356 (ALTHIX) and Aι2024 with d×ι=60×90 (mm) to obtain the globular microstructure is theoretically proposed. The suitability of an optimal coil design will be demonstrated by reheating experiments. Finally, the thixoformability of an arbitrarily shaped product is evaluated by its forming variables. The defects and mechanical properties are also investigated.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.207-214
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• 2003

3D Modeling Solution can reduce projecting error and also make possible to design visually, so that it can minimize human resources. On the other hand, it has defects of operating difficulties caused by too much complex function, thus it consequently prevent user from prompt handling. According to this paper, the developed party S/W will help that user can construct the parts easily, can let everybody use 3D modeling solution readily, and make fast development of new product. This software will carry out prompt development of new product and derive satisfaction of customers from high quality. Also, saving time and expense naturally raise competitive power in consequence.

• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.257-266
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• 2003

3D Modeling Solution can reduce projecting error and also make possible to design visually, so that it can minimize human resources. On the other hand, it has defects of operating difficulties caused by too much complex function, thus it consequently prevent user from prompt handling. According to this paper, the developed party S/W will help that user can construct the parts easily, can let everybody use 3D modeling solution readily, and make fast development of new product. This software will carry out prompt development of new product and derive satisfaction of customers from high quality. Also, saving time and expense naturally raise competitive power in consequence.