http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
알루미늄 합금 대기부식 예방을 위한 대한민국 공군 항공기 세척주기 최적화 연구
박원동 ( Won Dong Park ),국필준 ( Phil Jun Gook ),조윤호 ( Younho Cho ),반치범 ( Chi Bum Bahn ) 한국부식방식학회 2016 Corrosion Science and Technology Vol.15 No.4
It is a common practice to conduct periodic washes at designated intervals in order to prevent the atmospheric corrosion of aircraft. The wash interval depends on the atmospheric conditions, but the wash intervals set by the U.S. Air Force were widely adopted in Korea without detailed knowledge of the background data. Therefore, it is necessary to determine our own wash intervals representing the atmospheric and geographical conditions in Korea. This study analyzed previous wash interval algorithms and atmospheric data in Korea. New wash intervals are then proposed based on the corrosion rate equation in ISO-9223:2012. Atmospheric corrosion testing was conducted using 7075 and 1050 aluminum alloy specimens to verify the accuracy of the corrosion rate equation in ISO-9223:2012. Test results showed a reasonable agreement with the corrosion rates predicted by the equation.
열원 입력과 비드 생성 방법이 원통형 다층 금속 용접 과정의 유한요소해석에 미치는 영향
박원동(Won Dong Park),반치범(Chi Bum Bahn),김지훈(Ji Hoon Kim) 대한기계학회 2017 大韓機械學會論文集A Vol.41 No.6
본 논문에서는 원통형 다층 이종 금속 용접부를 대상으로 유한요소 해석을 수행하여, 열원 입력 방법과 용접 비드 생성 방법이 용접 잔류 응력 분포에 미치는 영향을 고려하였다. 열원 입력 방법은 열속 입력 방법과 온도 경계조건 입력 방법으로 나누어 비교하였고, 용접 비드 생성 방법은 요소망 생성 방법과 평온 요소망 방법으로 나누어 비교하였다. 두 열원 입력 방법에 따른 열 해석 결과는 차이가 있었으나, 응력 해석 결과는 유사하였다. 이것은 고온(약 1000 ℃ 이상)에 노출되었던 영역이 비슷하고, 고온에서 재료의 강도가 매우 낮아 용접 비드의 온도가 용접잔류응력에 미치는 영향이 미미하기 때문이다. 두 용접 비드 생성 방법의 용접 잔류응력 분포는 유사하였지만 요소망 생성 방법 적용 시 용접 비드 경계에서 겹침과 들뜸이 발생하였다. 대변형이 발생하는 모델의 용접부 형상을 정확하게 모사하기 위해서는 평온요소망이 더 적합하다고 판단된다. In this study, a finite element analysis of a cylindrical multi-pass weldment for dissimilar metals was performed. The effects of the heat input method and weld bead generation method were considered. We compared two heat input methods: the heat flux method and the temperature method. We also compared two weld bead generation methods: the element birth method and the quiet element method. Although the results of the thermal analysis show deviations between the two heat input methods, the welding residual stresses were similar. Because the areas exposed to high temperature were similar and the strength of the material was very low in high temperature (above the 1000 ℃), the effects of the weld bead temperature were insignificant. The distributions of the welding residual stress were similar to each other. However, gaps and overlaps occurred on the welding boundary surfaces when the element birth method was applied. The quiet element method is more suitable for a large deformation model in order to simulate a more accurate weld shape.
원동조(Dong-Jo Won),박상훈(Sang-Hoon Park),박소리(So-Ri Park),이수원(Su-won Lee),원충연(Chung-Yuen Won),정용채(Yong-Chae Jung) 전력전자학회 2008 전력전자학술대회 논문집 Vol.- No.-
This paper presents a novel soft switching topology with resonant DC-DC converter and inverter. The resonant DC-DC converter consists of the auxiliary switch, resonant capacitor and inductor. All switches in the proposed topology is turn on at ZCS and turn off at ZVS operation. The proposed soft switching technology can be obtained the reduced switching losses and voltage and current stress of the power devices. Therefore, the resonant converter efficiency is higher than conventional boost converter. Simulation results on a 1kW soft switching converter are presented.
박택진 ( Taek Jin Park ),원동호 ( Dong Ho Won ) 한국정보처리학회 2004 정보처리학회논문지 C : 정보통신,정보보안 Vol.11 No.5
In the secret sharing scheme, the reconstruction secret must to exposed to participants. In order to enforce the same secret sharing schemes, a new secret have to regenerate and redistribute for participants. Such a regeneration process is inefficient because of the overhead in the regeneration. In this paper, we proposed efficient secret regeneration scheme by eigenvalue. it can be also redistribution without revealing with other participants.
박택진,원동호,Park, Taek-Jin,Won, Dong-Ho 한국정보처리학회 2004 정보처리학회논문지 C : 정보통신,정보보안 Vol.11 No.5
비밀분산방식에서, 재구성된 비밀은 참가자에게 노출된다. 동일한 비밀분산 방식을 유지하기 위해서, 새로운 비밀을 생성하고 참가자에게 재분배하여야 한다. 그러한 재생성과정은 비효율적이다. 본 논문은 참가자에게 노출되지 않고 고유치에 의해 효율적인 비밀 재생성과 재분배할 수 있는 방식을 제안한다. In the secret sharing scheme, the reconstruction secret must to exposed to participants. In order to enforce the same secret sharing schemes, a new secret have to regenerate and redistribute for participants. Such a regeneration process is inefficient because of the overhead in the regeneration. In this paper, we proposed efficient secret regeneration scheme by eigenvalue. it can be also redistribution without revealing with other participants.
수화열 해석을 통한 매트기초의 양생방법에 관한 해석적 연구
이원동(Lee Won-Dong),지남용(Jee Nam-Yong),박기봉(Park Ki-Bong),정행철(Jung hang-Chul),강대훈(Kang Dae-Hun) 대한건축학회 2007 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.27 No.1
Recently, the technique of mass concrete has been used on construction site By high-rise building and large sized building. Mass concrete occurs a temperature stress by heat of hydration. It cause for a temperature crack. It used many methods for reducing a temperature crack because a temperature crack affects to reduce the strength and durability of concrete. In the examination of occurring the generation of a temperature cracking, it needs the evaluation of thermal cracking index. Therefore this study shows properly curing method of mat foundation for reducing a temperature cracking with the thermal cracking index. For them, it tried to analyze internal temperature and thelmal cracking index based on the thickness of concrete and curing method.
이보영(Lee Bo Young),박택진(Park Taek Jin),원동호(Won Dong Ho) 한국정보처리학회 1999 정보처리학회논문지 Vol.6 No.3
Itakura and Nakamura proposed the first multisignature scheme based on the RSA signature scheme. But if many users sign on one paper, then their scheme has a reblocking problem. In 1991, Ohta and Okamoto proposed a multisignature scheme by using Fiat-Shamir signature scheme. But in this scheme, the group of signers must generate common random number in the first round, and in the second round, they sign the message with common random number. Also L. Harn proposed a multisignature scheme which is based on the E1Gamal's. In korea, S.D.Kim et al. at ICEIC'95 conference, proposed an efficient sequential multisignature scheme by using the modified Park-Won scheme. This scheme is not require an additional round to generate common random number, and has fixed signature length. In this paper, we analyze problem of Kim's multisignature scheme, and propose a new multisignature scheme based on R(th-) residuosity problem.
SSL 프로토콜의 CipherSuite 설정 문제점과 해결 방안
이윤영,허순행,박상주,신동휘,원동호,김승주,Lee, Yun-Young,Hur, Soon-Haeng,Park, Sang-Joo,Shin, Dong-Hwi,Won, Dong-Ho,Kim, Seung-Joo 한국정보처리학회 2008 정보처리학회논문지 C : 정보통신,정보보안 Vol.15 No.5
인터넷과 정보통신기술의 사용이 일반화되면서 인터넷 상에서 중요한 데이터를 안전하게 전송해야 함에 따라 SSL 프로토콜의 사용은 필수요소가 되었다. SSL 프로토콜은 메시지 위/변조 공격과 같은 능동적인 공격에 안전하도록 설계가 되었지만 CipherSuite 설정 변경은 별다른 제약 없이 수정이 가능하다. 공격자가 Client의 시스템의 오작동을 유도하여 CipherSuite 설정을 키 길이가 낮은 대칭키 알고리즘으로 변경한다면 도청하여 데이터를 해독할 수 있다. 본 논문은 키 길이가 낮은 대칭키 알고리즘 설정에 대한 국내 웹사이트의 보안세션 생성 조사 및 CipherSuite 설정 문제점에 대한 해결책을 제시한다. As the use of Internet and information communication technology is being generalized, the SSL protocol is essential in Internet because the important data should be transferred securely. While the SSL protocol is designed to defend from active attack such as message forgery and message alteration, the cipher suite setting can be easily modified. If the attacker draw on a malfunction of the client system and modify the cipher suite setting to the symmetric key algorithm which has short key length, he should eavesdrop and cryptanalysis the encrypt data. In this paper, we examine the domestic web site whether they generate the security session through the symmetric key algorithm which has short key length and propose the solution of the cipher suite setting problem.