• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.453-469
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• 2016

Many image fusion quality assessment techniques, which include Wald's, QNR and Khan's protocols, have been proposed. A total procedure for the quality assessment has been defined as the quality assessment protocol. In this paper, we compared the performance of the three protocols using KOMPSAT-2/3/3A satellite images, and tested the applicability to the fusion quality assessment of the KOMPSAT satellite images. In addition, we compared and analyzed the strengths and weaknesses of the three protocols. We carried out the qualitative and quantitative analysis of the protocols by applying five fusion methods to the KOMPSAT test images. Then we compared the quantitative and qualitative results of the protocols from the aspects of the spectral and spatial preservations. In the Wald's protocol, the results from the qualitative and quantitative analysis were almost matched. However, the Wald's protocol had the limitations 1) that it is timeconsuming due to downsampling process and 2) that the fusion quality assessment are performed by using downsampled fusion image. The QNR protocol had an advantage that it utilizes an original image without downsampling. However, it could not find the aliasing effect of the wavelet-fused images in the spectral preservation. It means that the spectral preservation assessment of the QNR protocol might not be perfect. In the Khan's protocol, the qualitative and quantitative analysis of the spectral preservation was not matched in the wavelet fusion. This is because the fusion results were changed in the downsampling process of the fused images. Nevertheless, the Khan's protocol were superior to Wald's and QNR protocols in the spatial preservation.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.256-258
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• 2006

철도신호제어장치는 열차의 안전운행을 책임지는 매우 바이탈한 제어장치이다. 이러한 바이탈 제어장치는 최근 들어 컴퓨터 및 통신기술의 발달에 따라 각 장치들간 인터페이스를 통한 통합 시스템화 되어가고 있다. 이에 따라 이들 각 장치들간 인터페이스를 위한 통신 프로토콜 또한 높은 안전성이 요구된다 국내에서 몇 년간의 연구를 통한 이러한 철도신호설비들간 인터페이스를 위한 통신프로토콜에 대한 연구가 이루어 졌으며 이를 통해 표준으로 제정되어 현재 적용되고 있다. 본 논문에서는 이러한 바이탈한 제어장치인 철도신호설비들간 통신프로토콜의 설계, 검증 그리고 표준화 과정의 분석을 분석하였다. 이러한 프로토콜의 설계 및 표준화 과정의 분석을 통해 높은 안전성이 요구되는 국내 적용 중인 통신프로토콜이 가지고 있는 안전성 특성을 확인하였다.

• Review of KIISC
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• v.12 no.2
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• pp.50-61
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• 2002

최근 전자상거래의 활성화 및 안전한 네트워크의 구현에 공개키 기반구조의 응용이 확대되면서 공개키의 무결성과 신뢰성을 제공하기 위해 공개키 인증서 상태 검증에 관한 연구가 활발히 진행되고 있다. 본 고에서는 PKI 응용 프로토콜 중에서 인증서의 유효성을 검증하기 위한 온라인 인증서 상태 검증 프로토콜(Outline Certificate Status Protocol)의 최근 연구 동향에 대하여 분석하였으며, 현재 상용화되어 있는 제품들에 대하여 조사하였다. 또한, 특정 인증서에 대한 온라인 취소 상태 확인 서비스(ORS: Online Revocation Status), 인증 경로의 발견을 서버로 위임하는 대리 인증 경로 발견 서비스(DPD: Delegated Path Discovery), 그리고 중앙 집중 서버에게 인증 경로 검증의 기능을 위임하는 대리 인증 경로 검증 서비스(DPV: Delegated Path Validation) 등의 온라인 인증서 상태 검증 프로토콜에서 제공하는 서비스들에 대해서도 살펴보았다. 현재 온라인 인증서 상태 검증 프로토콜(OCSP)에 관한 문서는 IETF에서 표준화한 RFC2560과 2000년 11월과 2001년 3월에 제안된 드래프트가 있으며, 본 고에서는 RFC2560과 제안된 드래프트를 비교 분석하였으며 국내\ulcorner외 제품의 동향과 온라인 인증서 상태 검증 프로토콜의 활용 범위에 대해서 간략하게 살펴보았다.

• Journal of the Korea Society of Computer and Information
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• v.8 no.1
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• pp.84-89
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• 2003

In this Paper, an improved protocol is proposed by supplementing a control station for transmission cycle management. This protocol is proposed to complement the shortcomings of the conventional L-Expressnet protocol which is used for round robin process in bus topology. We analyzed the improved protocol in channel utilization viewpoint and compared the result with that of the conventional protocol. From this result, we showed that the channel utilization of the improved protocol is superior to that of the conventional protocol when a maximum normalized propagation delay is increased.

• Journal of the Korea Society of Computer and Information
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• v.8 no.2
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• pp.106-111
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• 2003

In this Paper, an improved protocol is proposed by supplementing a control station for transmission cycle management and slot-extension function. This protocol is proposed to complement the shortcomings of the conventional L-Expressnet protocol which is used for round robin process in bus topology. We analyzed the improved protocol in channel utilization viewpoint and compared the result with that of the conventional Protocol. From this result, we showed that the channel utilization of the improved protocol is superior to that of the conventional protocol when a maximum normalized propagation delay is increased.

• Review of KIISC
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• v.12 no.6
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• pp.81-92
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• 2002

cdma2000 1xEV(Evolution)-DO(Data Only)는 기존의 IS-2000 무선 프로토콜과 달리 패킷 데이터 서비스를 위한 전용 프로토콜로, 최대 2.4Mbps의 전송 속도를 제공한다. cdma2000 1xEV-DO는 이전의 프로토콜과 단리 무선 인터페이스 계층 구조에 따로 분리된 시큐리티 계층(security layer)을 가지며, 이 시큐리티 계층에서 패킷 데이터 서비스를 위한 인증과 암호화 서비스를 제공한다. 본 고에서는 패깃 데이터 서비스를 위한 전용 프로토콜인 chma2000 1xEV-DO의 시큐리티 계층의 4가지 프로토콜인 키 교환 프로토콜, 인증 프로토콜, 암호화 프로토롤, 시큐리티 프로토콜을 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.9
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• pp.1332-1347
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• 1993

Existing instruments are composed independently according to their function and user constructed instrumentation system with those instruments. But in the late 1980s VXI bus enables to construct instrumentation system with various modular type instruments. For an VXI bus system with the word serial protocol, an increase of data size can degrade the system performance. In this paper shared memory protocol is proposed to overcome performance degradation. The shared memory protocol is analyzed using the GSPN and compared with that of the word serial protocol. It is shown that the shared memory protocol has a better performance than the word serial protocol. The VXI bus message based-system with the proposed shared memory protocol is constructed and experimented with signal generating device and FFT analyzing device. Up to 80 KHz input signal the result of FFT analysis is accurate and that result is agree with that of conventional FFT analyzer. In signal generating experiment from 100 KHz to 1.1 GHz sine wave is generated.

• Convergence Security Journal
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• v.3 no.2
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• pp.33-40
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• 2003

The biggest problem for the oblivious transfer protocol is the rapid increasement of network traffic and computational complexity if the protocol is used as a sub-protocol compare to the case that when it is used as a standalone protocol. To fix such problems, in this paper, we propose a verifiable Non-interactive OT protocol that reduces the network traffic and computational complexity by preprocessing the necessary computations when the network traffic is low. The proposed protocol uses third root mechanism instead of square root mechanism that is used for the Fiat-Shamir signature mechanism and also uses 1-out-of-2 oblivious transfer based on signature mechanism. We also analyze the proposed protocol by comparing to the Lein Harn, YNIOT protocols.

• Convergence Security Journal
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• v.6 no.1
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• pp.45-53
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• 2006

It has been proposed that several RFID authentication protocols based on hash chain. Status based authentication protocol and challenge-response based authentication protocol are secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks but are vulnerable to Dos attacks. RFID authentication protocol with strong resistance against traceability and denial of service attack is secured against location tracking attack, spoofing attacks, replay attacks, DoS attacks but are vulnerable to traffic analysis attacks. The present study suggests a more secure and lightweight RFID authentication protocol which is combining the advantages of hash-chain authentication protocol and RFID authentication protocol with strong resistance against traceability and denial of service attack. The results of the secure analysts for a proposed protocol are illustrated that it is secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks, Dos attacks and is a lightweight operation between server and tag.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.1
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• pp.17-27
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• 2005

With the development of wire and wireless based networks, a various security protocols have been proposed to protect important resources and user information against attackers. However, many security protocols have found oかy to be later vulnerable to attacks. In this Paper, we introduce the formal methodology to verify the safety of security protocols in the design phase, and we take advantage of the formal methodology which uses Casper/CSP and FDR tools by introducing the verification example of EKE protocol and BCY protocol. Lastly, we propose a new BCY protocol after verifying it's safety.