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복합센서의 전후방 신호에 대한 음향진동 정합기법을 이용한 수동소나 탐지성능 향상에 대한 연구
서동완,장우석,김동현,노응휘,양정은 한국음향학회 2024 韓國音響學會誌 Vol.43 No.2
함정 선체부착형 수동소나체계는 최근 표적탐지성능을 향상시키고자 함내 진동유기 소음을 제거하려는 연구가 활발히 진행중이다. 본 연구진은 신호처리의 관점에서 음향센서와 진동센서가 설치된 복합센서를 이용한 음향-진동 정합기법을 개선책으로 제시한다. 본 논문에서는 정합기법의 이론적 배경에 대해 기술한 후, 그것이 다중물리 유한요소해석 상에서 실현됨을 보였다. 나아가 정합기법을 센서 시스템에 적용할 시의 표적신호 수신감도 상승 및 진동유기 소음 제거 성능을 산출하였으며, 정합기법의 실용성과 향후 연구방향에 대해 논하였다. Recently, ship hull-mounted passive sonar system solution is needed in the perspective of improving target detection and elimination of vibration-induced noise. Our research team suggests acousticvibration matching method using front and rear signal of a sensor as the improvement of the problem above. Thus in this paper, theoretical background about matching method and its application on finite element method based multi-physics simulation are described. Furthermore, it is shown that target detection and hull vibration performance are improved by using matching method under the condition of our sensor system. Finally, practicality and future research are discussed.
서동완,Young Don Lim,Soon Ho Lee,Soon Chul Ur,김환기 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.8
A new type of ionic liquid based on N-(3-aminepropyl)imidazolium iodide, called IIQAI, which consists of imidazolium and quaternary ammonium salt, and APII-(hydroxyethyl, propyl, hexyl) were synthesized and used as ionic liquid in dye-sensitized solar cells. APII-hexyl is solid, whereas IIQAI, APII-(hydroxyethyl,propyl) are viscous liquids. The synthesized ionic liquid showed relative thermal stability compared to the commercial ionic liquid of DMII. Among them, IIQAI was more stable than the other ionic liquid because of the two salt groups. APII-hydroxyethyl, which contains two hydroxyl groups, showed low viscosity with good flow. New types of ionic liquids were examined by ^1H-NMR spectroscopy, thermo gravimetric analysis (TGA). IIQAI enabled a solar energy conversion efficiency of 6.3%, which is slightly higher than that of the referenced (DMII, 6.2%).
Synthesis and Properties of Polycarbonate-co-Poly(siloxane-urethane-siloxane) Block Copolymers
서동완,김환기,권영도,김재현,장호현,임영돈,이순호,이동규 한국고분자학회 2012 Macromolecular Research Vol.20 No.8
Polycarbonate-co-poly(siloxane-urethane-siloxane) block copolymers (SiUrPC) were synthesized from siloxane-urethane monomer and polycarbonate (PC) oligomer, and their properties were compared with those of linear Bisphenol A PC (BPA-PC) and siloxane PC (SiPC). The synthesized polymers were characterized by 1H NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). The contact angle of the sessile water drop onto the polymer films was also measured. The thermal and mechanical properties of SiUrPC differed from those of BPA-PC and SiPC. SiUrPC exhibited superior flow properties and lower wettability than BPA-PC.