This study identified the core competencies of aircraft maintenance quality engineers and compared the importance and retention of core competencies. Through literature research, 21 core competencies were derived in three areas of management technology, elemenal technology and collaboration technology, and a survey was conducted on the importance and retention of core competencies for 42 aircraft maintenance quality engineers. As a result of the survey, the importance of all core competencies of aircraft maintenance quality engineers is 3.95/5 on average, and the retention of all core competencies is 3.99/5 on average. 'Risk Management’, ‘Creating Document’, ‘Honesty/Moral’ were identified as the most important competencies in each area, and ‘Quality Management’, ‘Language’, ‘Honesty/Moral’ were identified as the most possessed competencies in each area. An IPA (Importance-Performance Analysis) was performed to analyze the details. Through IPA, ‘Risk Management’ and ‘Safety Management’ were evaluated as having a low degree of retention compared to a high level of importance. Therefore, they were identified as a core competencies that need to be improved first. In addition, the characteristics of each core competency and the recognition level in the field were also identified. This study will be helpful in defining the roles and functions of aircraft maintenance quality engineers to improve flight quality and prevent aviation accidents.

This study discussed the effects of inclined interface location to apply the design of inclined interface of composite materials subjected to shear loading. The fracture parameters are analyzed by finite element method of ANSYS. As a results, If in case of the angle of inclination is 45 degrees, inclined interface is longer and the crack tip is closer, the less the crack suppression effect. If the inclined interface location is a more than twice the length of the inclined interface, the effect of suppressing crack propagation are constant regardless of the location. In case of the inclined interface is longer and the crack tip is closer, the cause of increase of energy release rate is a due to the increase of shear stress. If in case of the angle of inclination is 90 degrees, inclined interface is closer to the crack tip, the better the crack suppression effect. If the inclined interface location is a less than twice the length of the inclined interface, the effect of suppressing crack propagation are dominant. And if the inclined interface location is a more than twice the length of the inclined interface, crack suppression effect is gradually reduced.

This study was discussed with the friction effects due to surface roughness of the interface between the base material and a reinforcement at the downward inclined interfacial crack under shear loading. The fracture parameter are analyzed by finite element method of the ANSYS. As the friction coefficient of the surface is assumed zero and 0.3, the fracture is analyzed. This study was analyzed with inclination angles about 0 degrees, 45 degrees and 90 degrees. As the results, at the inclination angle of 0, the energy release rate is reduced by about 3%. About 16%, and 2% are decreased at 45 degree and 90 degree respectively. If the inclination angle is 45 degrees, the friction effect by the sliding resistance between the interface was found to be most effective.

This study discusses the length effect of the downward inclined surface to apply the inclined interface surface design of the composite material under shear loading. The fracture parameter is analyzed by finite element method of the ANSYS. If the negative shear displacement is applied, energy release rate is reduced further to about the increasing inclined length, and the positive shear displacement applied, it had increased rather. If the negative shear displacement is applied, the reduction in the energy release rate in crack tip is found to be affected by the reduction in shear stress. If the positive shear displacement is applied, the increasing in the energy release rate in the crack tip is found to be affected by the increase in shear stress.

In this study, the effect of downward inclined interface about interfacial crack of bimaterials are discussed. The fracture parameter are analyzed by finite element method of the ANSYS. The energy release rates, displacement jump and stress distribution were analyzed as the gradient variation of inclined interfaces. As a results, in case of positive shear displacement was applied, the energy release rates not varied with gradient of inclined interface increasing. However in case of negative shear displacement was applied, the energy release rates decreased with gradient of inclined interface increasing. Due to the inclined interface contact, the shielding effect relatively increased as the gradient of inclined interface was increased.

Micro structure observation for low carbon steel base material and heat treatment(annealing), performing a tensile test and impact test, the specimen after the impact test is intended to evaluate the crack propagation characteristics by performing a fractal dimension analysis. The tensile strength of the base materials were observed higher compared to the heat treated materials, impact absorbed energy of heat treated materials was a higher than base materials. Impact Test and fractal dimension of the side of the test specimen was shown significantly more test temperature increases, heat treated material was higher than the base material

In this study, the crack initiation and propagation behavior of interfacial crack in bimaterial are discussed. Normal crack opening displacements(NCOD) and stresses are analyzed by finite element method using ANSYS and used for extracting fracture parameters. The energy release rates can not explained the initiation and crack propagation velocity of interfacial crack. Initial velocity of crack propagation is dependent upon the normal and shear stress behind of crack tip. The crack propagation velocity of interfacial crack is very dependent upon the normal and shear stress behind of crack tip. In case of negative shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the negative shear stress ahead of crack tip due to the suppressing of crack opening. In case of positive shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the stress behind of crack tip due to the stress decrease. The fracture toughness increase is due to the initiation delay of crack propagation.

In this study, the effect of interface friction coefficient about interfacial crack of bimaterials are discussed. The fracture parameters are analyzed by finite element method using ANSYS. With increasing the interface friction coefficient, normal crack opening displacements and normal stress distributions are analyzed. In this case with surface contact in interface crack, the energy release rates decreases with interface friction coefficient increasing. Increase in the friction coefficient of the crack surface are tend to suppressing for the initiation of interfacial crack. In this case with surface non-contact, the energy release rates are constant with interface friction coefficient increasing, and so the friction coefficient are not related with the fracture parameter.

한국원자력연구원에서 개발 중인 해체기술 현황 및 전망에 대해 기술하였다. 특히, 해체의 핵심기술인 제염, 원격절단, 해체 폐기물처리 및 부지 복원 분야를 중점적으로 다루었다. 제염기술로는 부품제염과 원자력시스템제염 부분을 고찰하였고, 원격절단기술 관련해서는 절단기술, 원격제어 및 해체공정 모사기술이 다루어졌다. 해체 폐기물처리기술 관련해서는, 비록 해체 후 다양한 폐기물이 발생하지만, 주 폐기물인 금속, 가연성폐기물과 난처리성 특수 폐기물인 고염 고방사성 폐액, 유기혼 성폐기물 및 우라늄 복합폐기물 처리기술 등을 주로 기술하였다. 마지막으로, 해체부지 복원 분야에서는 방사선 측정, 부지 재이용의 안전성평가 그리고 부지 복원기술 등을 중점적으로 기술하였다.