http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
염수환경 내 해드필드강 용접열영향부의 부식 및 침식-부식 거동에 미치는 Cr 첨가의 영향
진승우,박진성,윤덕빈,이상철,최종교,오민석,김성진 대한금속·재료학회 2023 대한금속·재료학회지 Vol.61 No.12
The corrosion and erosion-corrosion behaviors in the weld heat-affected zone (HAZ) of Hadfieldsteels with varying Cr contents (1, 2, and 3 wt%) were examined. Various experimental methods, includingelectrochemical polarization, impedance, and weight loss measurements, were utilized. Two types of isothermalheat treatments were conducted in a box furnace to simulate the intercritical HAZ, known to be themost vulnerable region in terms of mechanical properties and environmental stabilities, and large-scalesamples for the erosion-corrosion experiment were fabricated. The results showed that increasing the Crcontent improved the resistance to corrosion and erosion-corrosion, but there was an inflection point whereadding more Cr had the opposite effect. Up to 2 wt%, a higher resistance was exhibited owing to the formationof a thin and protective oxide scale enriched with Cr that adhered to the steel surface. On the other hand,adding 3 wt% of Cr resulted in decreased resistance. This was due to the formation of coarse M7C3 (M: Cr)precipitated along the grain boundary, which caused the development of a thick and unstable oxide scale thatdetached locally. Based on these findings, it is essential to optimize the Cr content to ensure a high resistanceto corrosion and erosion-corrosion in the HAZ of Hadfield steel.
진승우,윤종호,김영익 한국항공우주학회 2005 한국항공우주학회 학술발표회 논문집 Vol.- No.-
T-50 Full-Scale Airframe Durability Test was conducted for two service lifetimes to verify the structural integrity of the airframe against its projected loads environment. After the completion of second life testing, a comprehensive teardown inspection was planned and conducted to identify and document all discrepancies in the structure, which had been initiated and/or propagated as a result of spectrum loading. From the teardown inspection, several discrepancies were found in wide spread structural components, primarily canopy floor support beam, wing carry through bulkheads, wing spars and ribs, wing lower skins and attach fittings, etc. Fractographic analyses, for the most notable inspection findings, were also performed to correlate test results with damage tolerance crack growth analysis models. From these correlation study, T-50 design practice of the damage tolerable single load path, slow crack growth approach was validated and the analysis methods utilizing a representative crack growth retardation parameter - a representative Willenborg Shut-Off Ratio in this study - were proved to be adequately conservative with a high degree of confidence. Design improvement were accomplished to resolve service life related discrepancies and to ensure structural integrity of production airframe.
데이터마이닝 기법을 이용한 모바일 야구 투구 예측 게임 프로토타입 개발
진승우,김병철,엄일규,김영인 한국정보기술학회 2014 한국정보기술학회논문지 Vol. No.
Due to increasing propagation and progressing performance of a smart device, mobile baseball game technologies have been developing rapidly. A tracking technology of pitches in a baseball game is developed, too. So gathering and analysis of more precise data than before is made possible by the technologies. The prediction ability of a pitch at a baseball game is an important factor determining the outcome of the game. Therefore the interest of baseball people concerning the ability of pitch prediction is growing. However there is still lack of developing efforts about predicting the pitcher’s pitches. In this paper, we develop a prototype using data mining techniques for a mobile baseball game which can guess and score the hits of the pitcher’s pitch. For this, we have collected the pitching-related data by ourselves, designed the database schema, developed the model using data mining techniques and implemented the prototype with the Android operating system. The result shows that the prototype runs successfully. The result of this study can be used for raising the understanding level of the pitcher’s pitching patterns and for developing more realistic games. 최근 스마트기기의 급격한 보급 증가와 성능 발전으로 모바일 야구 게임 기술이 발전하고 있다. 야구 경기에서 투수의 투구를 추적하는 기술도 발전하여 이전보다 더욱 세밀한 데이터의 수집과 분석이 가능하여졌다. 그러나 아직까지 야구 경기의 승패를 가르는 중요 요소이면서 사용자의 관심도 증가하고 있는 투수의 투구를 예측하여 맞히는 게임 개발에 대한 노력은 부족한 실정이다. 본 논문에서는 데이터마이닝 기법을 이용하여 투수의 투구를 예측하여 맞히는 모바일 야구 게임의 프로토타입을 개발하고자 한다. 이를 위해서 투구 관련 데이터를 직접 수집하여 데이터베이스를 설계하고 데이터마이닝 기법으로 예측 모델을 구축하여, 안드로이드 기반 스마트폰에 사용할 수 있도록 구현하였다. 구현 결과, 게임 실행이 성공적으로 이루어짐을 보였다. 본 연구의 결과를 활용하여 사용자가 투수 투구의 패턴을 이해하는 수준을 높일 수 있고, 보다 현실감 있는 게임 개발에 기여할 수 있다고 판단된다.
실제 비행자료를 이용한 한국공군 F-16 블록 32 기골 내구성 및 손상허용해석 최신화
진승우,조환정,백세일,문창오 한국항공우주학회 2013 한국항공우주학회 학술발표회 논문집 Vol.2013 No.11
한국공군 F-16C/D Block 32 수명관리 최신화를 수행하기 위해, 항공기에 장착된 비행기록장치로부터 내려 받은 비행자료를 분석하여 기준 운용하중 스펙트럼을 단좌 및 복좌 형상에 대해 각각 개발하였다. 또한 개발된 스펙트럼을 적용하여 한국공군 F-16 단좌 및 복좌 형상에 대한 내구성 및 손상허용해석을 최신화하였다. 한국공군 고유의 운용하중 스펙트럼을 수명해석에 적용하였기 때문에 내구수명과 손상허용 초기검사 주기가 현재 정비 활동의 기준인 미국공군 데이터에 비해 상당히 증가함을 확인하였다. 결론적으로, 이러한 한국공군 고유의 해석결과가 향후 F-16 기골 정비 활동을 위한 기초 데이터로 사용될 경우 비행 안전성은 유지하면서 정비 비용은 줄이고, 항공기 가동률을 높이는 데 기여할 수 있을 것으로 기대된다. For the purpose of Republic of Korea Air Force(RoKAF) F-16C/D Block 32 Force Management Update(FMU), the baseline operational loads spectra were developed for F-16C and F-16D models based on actual flight measured data from Crash Survivable Fight Data Recorder(CSFDR) equipped in F-16C/D Block 32 fleet. The durability and damage tolerance analyses were updated with the RoKAF baseline operational loads spectra (fleet average normal severity) for F-16C and F-16D models. Due to the application of RoKAF unique in-service loads spectra, the durability life and damage tolerance initial inspection interval have been increased considerably compared to previous USAF data. In conclusion, since the results of these analyses provide a basis for the airframe maintenance activities of the RoKAF Block 32 aircraft, it is expected that maintenance cost is decreased and fleet readiness is increased, while maintaining flight safety.