• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.10a
• /
• pp.333-335
• /
• 2014

20년 이상의 에이징 테스트와 브레이킹 테스트를 걸친 모빌리스 부이는 해상에서 저항력이 강한 특수 폴리에틸렌 재질로 제작된다. 국제항로표지협회 (IALA AISM)에서 공식 계류라인 소프트웨어로 선정한 CALMAR를 직접 개발함으로써 기존 강철 부이에 비해 우월한 안전성과 긴 수명, 간단한 유지보수, 현저한 유지비용 감소 등 다양한 장점을 지니고 있다. 전 세계적인 부이 사용의 추세가 변화됨에 따라 국내에도 보다 좋은 해양발전을 위해 플라스틱 부이를 소개한다.

• Annual Conference on Human and Language Technology
• /
• 2023.10a
• /
• pp.149-154
• /
• 2023

본고는 한국어 생성 모델의 독성 텍스트 저항 능력을 검증하기 위해 'CVALUE' 데이터셋에서 추출한 고난도 독성 질문-대답 100쌍을 바탕으로 한국어 생성 모델을 위한 '100 K-Poison' 데이터셋을 시범적으로 구축했다. 이 데이터셋을 토대로 4가지 대표적인 한국어 생성 모델 'ZeroShot TextClassifcation'과 'Text Generation7 실험을 진행함으로써 현재 한국어 생성 모델의 독성 텍스트 식별 및 응답 능력을 종합적으로 고찰했고, 모델 간의 독성 텍스트 저항력 격차 현상을 분석했으며, 앞으로 한국어 생성 모델의 독성 텍스트 식별 및 웅대 성능을 한층 더 강화하기 위한 '이독공독(以毒攻毒)' 학습 전략을 새로 제안하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.11
• /
• pp.903-910
• /
• 2020

This paper introduces a simulator to assess the impacts of the wind and the airframe vibration on the performance of the Active Electronically Scanned Array (AESA) radar mounted in an aircraft. The AESA radar is mounted on the nose cone of an aircraft, and vibration occurs due to the drag force. This vibration affects the behavior of the AESA radar and can cause phase errors in signal. The simulator adopts the geometric model for nose cone, the mathematical models on the rigid-body dynamics of the aircraft, the average/turbulent winds, and the mode/ambient vibrations to compute the position and the attitude of the radar accurately. Numerical studies reflecting a set of test scenarios were conducted to demonstrate the effectiveness of the developed simulator.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.5A
• /
• pp.307-315
• /
• 2012

Recently, ultra high performance fiber reinforced concrete (UHPFRC) having over 180 MPa compressive strength and 10 MPa tensile strength has been developed in Korea. However, UHPFRC represents different material properties with normal concrete (NC) and conventional high performance concrete (HPC) such as a high early age autogenous shrinkage and a rapid dry on the surface, because it has a low water-binder ratio and high fineness admixtures without coarse aggregate. In this study, therefore, to propose suitable experimental methods and regulations, and to evaluate mechanical properties at a very early age for UHPFRC, setting, shrinkage and tensile tests were performed. From the setting test results, paraffin oil was an appropriate material to prevent drying effect on the surface, because if paraffin oil is applied on the surface, it can efficiently prevent the drying effect and does not disturb or catalyze the hydration of cement. From the ring-test results, it was defined that the shrinkage stress is generated at the time when the graph tendency of temperature and strain of inner steel ring is changed. By comparing with setting test result, the shrinkage stress was firstly occurred as the penetration resistance of 1.5 MPa was obtained, and it was about 0.6 and 2.1 hour faster than those of initial and final sets. So, the starting time of autogenous shrinkage measurement (time-zero) of UHPFRC was determined when the penetration resistance of 1.5 MPa was obtained. Finally, the tensile strength and elastic modulus of UHPFRC were measured from near initial setting time by using a very early age tensile test apparatus, and the prediction models for tensile strength and elastic modulus were proposed.

• Conservation Science in Museum
• /
• v.29
• /
• pp.133-152
• /
• 2023

This study references preceding studies to examine the history of paint application techniques using various paints in the past, with the aim to contribute to the long-term preservation of large military cultural heritage assets situated outdoors. To this end, the study compared the findings of preceding research with the findings of an analysis conducted on a H-13 helicopter housed at the War Memorial of Korea. Upon collecting and analyzing samples from three grounded WWII aircraft from above-ground by preceding studies, it was confirmed from each sample that the various chemical properties of chrome ensured the effectiveness of the protective coating. The compound was first tested as a corrosion-inhibiting pigment in the early 1940s and proved its excellent moisture-resistant properties over the course of 80 years, despite the deterioration of the paint layer and long-term exposure to the natural environment. For this reason, it has been widely used as a corrosion inhibitor for aluminum alloys in the aviation industry. In other word, the most widely-used material for preventing corrosion was an organic primer containing chromate. In this study, based on the paint analysis of a H-13 helicopter operated in the Korean War, it was shown that the second layer, consisting of the primer, contains chromium oxide (Cr₂O₃). In addition, it was estimated that red lead tetraoxide (Pb₃O₄) was used for the vehicle. Analysis results and data from previous studies can help to confirm the continued effectiveness of corrosion prevention function provided by chromate. Meanwhile, the result of infrared spectroscopy analysis confirmed the use of alkyd resin. In the future, comparisons with a more diverse range of artifacts will allow the identification of changes in the manufacturing technology of paints used to protect alloys from corrosion.