• Korean Architects
• /
• no.7 s.148
• /
• pp.49-62
• /
• 1981

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2012.10a
• /
• pp.315-316
• /
• 2012

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2011.10a
• /
• pp.467-468
• /
• 2011

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10a
• /
• pp.655-657
• /
• 2003

시스템 콜 서열(system cail sequence)을 기반으로 한 침입 탐지 기법에는 다양한 알고리즘들이 사용되어 왔으며, 시스템 콜 서열을 인식하는 오토마타를 생성하는 기법도 많이 연구되었다. 그러나 효율적인 오토마타를 생성하는 것은 계산복잡도가 높은 어려운 작업이다. 본 논문에서는 유전자 알고리즘을 사용하여 자동적으로 오토마타가 생성되는 과정을 설명하며, 생성된 오토마타가 침입방지에 효과적으로 이용될 수 있음을 실험을 통하여 보인다.

• Information and Communications Magazine
• /
• v.13 no.8
• /
• pp.103-122
• /
• 1996

초고속정보통신망의 구축이 효율적이고 신뢰성 있는 서비스를 제공하기 위하여 위성/지상망을 통합한 혼합망 구조로 개발됨에 따라 지상 광파이버를 기반으로 개발된 ATM 전송프로토콜을 위성망에 직접적으로 적용하기 위한 기술개발이 요구된다. 이러한 점을 고려하여 본 고에서는 위성 ATM(Asynchronous Transfer Mode) 전송에 따른 문제점 분석, 개선방안 및 성능평가를 수행하였다. 혼합망 구성에 따른 위성망의 구조를 접속된 지상노드의 유형 및 위성시스템 특성에 따라 3가지 유형으로 분류하여 제시하였고, 위성 ATM 전송에 따른 기술적인 문제점을 채널 BER과 위성지연 측면으로 분류하여 제시하였다. 위성채널 BER 성능개선을 위한 2가지 방안(인터리빙, HEC 보강)을 제시하였으며 위성지연분석은 고정지연(Fixed delay)과 셀지연변이(CDV : Cell Delay Variation) 측면에서 성능평가를 수행하였다.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.5
• /
• pp.10-23
• /
• 1996

In this paper, the reverse link performance evaluation with synchronous CDMA is analyzed in the PCS system, which is the schem based on proposed method of KMT-PCS to increase the capacitance of cellular CDMA system. We make the baseband system model of CDMA reverse link, and then analyze system performance and subsystem techniques considering effect of channel and power control that are improtant factor influencing system performance in the PCS system. Based on this result, the paper presents primary technique analyses required at synchronous reverse link proposed by the KMT, which compose of initial synchronization range in initial synchronization step and control signal period in the synchronization maintenance step.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.3
• /
• pp.9-18
• /
• 1998

For constructionof the next generation satellite B-ISDN/ATM networks considering integration with terrestrial information infrastructure networks, various high speed and wideband satellites with be launched and they will make used of frequency reue techniques for efficient management of limited frequency resource. Therefore, CCI(Co-Channel Interference) inherent in frequency reuse will be a dominant factor in performance degradation of satellite networks. This paper alanyzes the ATM cell transmission performance degradation caused by CCI. The satellite link, including up-link and down-link thermal noise, CCI, and nonlinear satellite transponder, is modeled and interleaving technique is used for compensating the ATM cell transmission performance degradation caused by burst error of satellite link. First, each satellite link subsystem is analyzed in detail and then end-to-end ATM cell transmission performance is evaluated with BER and CLR. Specifically, ATMcell transmission performance degradation caused by CCI is evaluated in detail.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.10
• /
• pp.2687-2702
• /
• 1996

It is desirable that the implementation of next generation information infrastructure is the Integrated Network combining the satellite and the terrestrial network. The application of the ATM network being the dominant infrastrure of terrestrial network to the satellite network is being studied variously. Considering these concepts, this paper analyzes due to ATM transport via satellite, evaluates the degradation of QoS and proposes reliable method of ATM cell transport via satellite. Because ATM is investigated with the optical fiber which is almost error free characteristics, the practical application of ATM transport via satellite essentially need the channel coding(FEC:Forward Error Correction) to enhance BER performance. But using the FEC coding, satellite link has burst error characteristics which evoke severe performance degradation fo ATM QoS. Therefore in satellite link, we analyze burst error characteristics using experimental results of computer simulation. Then to compensate these characteristics, based on this analysis and HEC dual mode algorithm we propose various interleaver structures(Block interleaver, Intra interlever, and Inter-Intra interleaver) to improve cell transmission QoS. We execute performance evaluations of iterleaver structures by computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.5
• /
• pp.1083-1096
• /
• 1997

To implement satellite B-ISDN/ATM network, it needs to gurantee reliable transport via satelite in the poor BER environment. So, it requires to use channel coding (FEC:Forward Error Correction) schemes for improvement of BER performance, but these coding effects evoke burst errors and degradation of the QoS. Therefore we have to investigate new algorithm that compensates these weaknesses. We consider convolutional coding and concatenated coding among FEC schemes as FEC for satellite transmission and choose different compensational algorithm by the error characteristics of the using type of FEC. In using concatenated coding, this paper proposes the satellite system structure for interconnection to the terrestrial network and proposes the channel coding algorithm for improvement of transmission performances. We execute performance evaluation of the proposed algorithm by computer simulation. In detail, we propose 4 types of application ATM cell to the block coding(Reed-Solomon) and propose the new 55 byte ATM cell that enforces the error correction capability of cell header by the BCH coding. Then we propose the outer interleaverand the cell unit interleaver that evoke maximum coding effect of BCH code.

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.1
• /
• pp.117-121
• /
• 2000

The mucormycosis is a group of serious opportunistic infections caused by fungi of the class Zygomycetes and order Mucorales. Pulmonary mucormycosis is a relatively rare disease but typically manifested by a rapidly progressive, often fatal pneumonia in patients with diabetes mellitus, hematologic malignant neoplasms, or organ transplants. The radiologic manifestations of pulmonary mucormycosis are nonspecific and include progressive lobar or multilobar consolidations, pulmonary masses and pulmonary nodules. Recently, we experienced a pulmonary mucormycosis in 32-year-old man with uncontrolled diabetes. He complained of cough, left pleuritic chest pain and generalized weakness. Initial chest X-ray finding was the consolidation on the lower lobe of the left lung. On the sixth hospital day, bronchoscopic examination with lung biopsy revealed broad, non-septate hyphae with right-angle branching, diagnostic of mucormycosis, and consequently amphotericin B therapy was started. We performed a lobectomy of the left lower lobe of the lung on 29th hospital day.