Search | Korea Science

박종철;강형택;박찬민
- Proceedings of the Korea Concrete Institute Conference
- /
- 2000.10a
- /
- pp.523-528
- /
- 2000
In multi-span bridges, a shear key is often used to distribute the seismic force to the case, the shear key is sometimes required to be reinforced to withstand the seismic force. To improve the strength of shear key, the strength and failure mode of shear key have to be carefully estimated and the proper reinforcement scheme should be elaborated. The test results show that the strength of shear key is 2.5 times higher than the strength calculated by PCI design handbook. Also the strength of shear key is greatly improved by placing PT bars into shear key. In this study, the analytical method to evaluate the strength of sheat key and the reinforcement scheme are proposed.
PDF

정지현;전승철;박성한
- Proceedings of the IEEK Conference
- /
- 2000.11c
- /
- pp.137-140
- /
- 2000
In this paper, we propose as new algorithm for the selection of key frames in a given video. For the selected key frames to be well defined, the selected key frames need to spread out on the whole temporal domain of the given video and guaranteed not to be duplicate. For this purpose, we take the first frame of each shot of the video as the candidate key frame to represent the video. To reduce the overall processing time, we eliminate some candidate key frames which are visually indistinct in the histogram difference. The key frames are then selected using a clustering processing based on the singly linked hierarchical tree. To make the selected key frames be distributed evenly on the whole video, the deviation and time difference between the selected key frames are used. The simulation results demonstrate that our method provides the better performance compared with previous methods.
PDF

Lu, Chung-Fu
- KSII Transactions on Internet and Information Systems (TIIS)
- /
- v.9 no.12
- /
- pp.5135-5149
- /
- 2015
Communications among multi-party must be fast, cost effective and secure. Today's computing environments such as internet conference, multi-user games and many more applications involve multi-party. All participants together establish a common session key to enable multi-party and secure exchange of messages. Multi-party password-based authenticated key exchange scheme allows users to communicate securely over an insecure network by using easy-to-remember password. Kwon et al. proposed a practical three-party password-based authenticated key exchange (3-PAKE) scheme to allow two users to establish a session key through a server without pre-sharing a password between users. However, Kwon et al.'s scheme cannot meet the security requirements of key authentication, key confirmation and anonymity. In this paper, we present a novel, simple and efficient multi-party password-based authenticated key exchange (M-PAKE) scheme based on the elliptic curve cryptography for mobile environment. Our proposed scheme only requires two round-messages. Furthermore, the proposed scheme not only satisfies security requirements for PAKE scheme but also achieves efficient computation and communication.
https://doi.org/10.3837/tiis.2015.12.022 인용 PDF KSCI KPUBS HTML

윤은준;류은경;유기영
- Proceedings of the Korean Information Science Society Conference
- /
- 2003.10a
- /
- pp.763-765
- /
- 2003
본 논문에서는 RFC 1760 표준 S/KEY 일회용 패스워드 인증 스킴이 서버 스푸핑 공격 재시도 공격 오프라인 패스워드 공격, 능동적 공격 등 여러 가지 공격에 취약함에 대해서 설명하고 이들 공격에 안전한 스마트 카드를 이용한 새로운 스킴을 제안한다. 본 논문에서 제안한 스킴은 스마트 카드를 이용한 안전한 S/KEY 일회용 패스워드 인증 스킴으로 기존의 S/KEY 일회용 패스워드 인증 스킴의 보안 문제점을 개선하였으며 상호 인증을 가능하게 하는 새로운 스킴으로 여러 가지 안전성 향상을 보인다.
PDF