• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.226-228
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• 2002

이동통신망이 발달하면서 기존의 인프라를 생성하였던 ATM망을 음성서비스에 활용하기 위한 Voice over ATM기술이 많은 발전을 하고 있다. 본 논문에서는 ATM 망에서 Low-bit-rate voice 트래픽을 처리하기 위해 1020개의 커넥션을 지원하는 AAL2 Voice gateway를 구현하였다. 본 논문에서 구현된 AAL2 Voice gateway는 ITU-T Recommendations 1.363.2와 1.366.2에 근거하여 설계하였다. 또한, SSCS(Service Specific Convergence Sublayer)와 CPS(Common Part Sublayer) 부계층을 모두 하드웨어로 구현하였다. 본 AAL2 Voice gateway는 VHDL로 구현되었으며, 이동통신망과 VoDSL의 Voice gateway에서 그 효용 가치가 높을 것으로 사료된다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.757-759
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• 2004

무선 통신 기술이 급속히 발전하면서 이동 중 데이터 통신이 가능하도록 하기 위한 연구가 활발하게 이루어지고 있다. 본 논문에서는 효율적인 이동성 제공 방안으로 멀티캐스트 기반 이동성 제공 방안을 제안하고 모의실험을 통하여 TCP 트래픽에 대한 성능을 분석하였다. 본 논문에서 제안한 방안은 이동 단말이 외부 도메인 내에서 핸드오프 시 자신의 위치 갱신을 멀티캐스트 그룹에 조인하는 방법으로 바인딩 갱신에 따른 추가적인 신호를 지역 내에서 처리함으로써 Mobile IPv6와 Hierarchical Mobile IPv6 보다 TCP 처리율을 높임을 알 수 있었다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.862-864
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• 2001

다양한 도메인에 있어서 이동 호스트의 서비스 접근은 이동성 계약에 의한 홈 도메인과 도메인간 인증에 의하여 이루어지고 있다. 그러나 다양한 서비스 제공자와 서비스들 그리고 수많은 이동 사용자들에게 있어서 홈 도메인에 의존 한 이동성 계약은 비효율적이며 실용적이지 못한다. 본 논문에서는 티켓에 기반 한 새로운 지불 프로토콜을 제안한다. 공개키 암호 시스템에 기반 한 제안된 티켓 기반 지불 프로토콜은 기존의 연고[1,2]와 비교하여 개선된 안전성과 확장성을 제공한다.

• 방재와보험
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• s.7
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• pp.54-57
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• 1977

• 기계와재료
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• v.20 no.3
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• pp.103-114
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• 2008

• 방재와보험
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• s.8
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• pp.58-63
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• 1977

• 기계와재료
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• v.3 no.4 s.10
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• pp.17-29
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• 1991

• Journal of The Korean Association of Information Education
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• v.15 no.1
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• pp.129-136
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• 2011

The aim of this study is to present the handover procedures and the performance comparisons of layered mobility management schemes for wireless mobile Internet. To investigate efficient mobility management schemes providing seamless information services in a mobile environment, this paper provided the detailed discussions of existing network layered mobility management scheme, including Mobile IPv4, Mobile IPv6, and new transport layer mobility management scheme, stream control transmission protocol (SCTP) based mobility architecture (SMA). Network simulator-2 (ns-2) was used to compare the performance between Mobile IPv6 and SMA in the wireless mobile Internet environment. Simulation results show that for typical network configuration and parameters, SMA has a lower handover latency, lower packet loss rate, and higher throughput than Mobile IPv6.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.76-81
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• 1985

Miscible displacement techniques were used to investigate the influence of the organic matter treatment on the mobility of Cd, Zn, and Cu through soil columns. The heavy metals moved most readily through the Bonryang soil (Typic Udifluvents) of relatively low in CEC, pH, and organic matter content. Most parts of Cd and Zn eluted within 7 pore volumes, but Cu eluted between 5 and 15 pore volumes. Although the Gangseo soil (Aquatic Eutrochrepts) had lower in CEC and organic matter content than the Gyorae soil (Typic Distrandepts), the heavy metals moved faster through the Gyorae soil than through the Gangseo soil. Cu eluted more slowly and in smaller quantities than Cd and Zn from the Bonryang soil, but did not eluted from the Gangseo and the Gyorae soils at all during the experimental period. The motility of the heavy metals from the Bonryang and the Gangseo soils was in the order of Cd>Zn>Cu, but that of the Gyorae soil was in the order of Zn>Cd>Cu. Cd and Zn eluted after 5 and 20 pore volumes respectively, from the Bonryang soil treated with 3% compost but Cu did not elute even after 30 pore volumes were collected. By 7% compost treatment only small amountssof Cd eluted after 20 pore volumes. The liming of the Bonryang soil retarded the mobility of Cd, Zn, and Cu. Humic acid treatment did not reduce the motility of the Cd and Zn to the extent observed in the Bonryang soil with compost, but reduced a little motility of Cu.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.3
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• pp.15-22
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• 1982

This paper presents analytic bending moment solution and resonance diagrams for a uniform beam of infinite length subjected to anaxial force and moving transverse load. Solutions are obtained that are time invariant in a coordinate system moving with the load velocity. The supporting foundation includes damping effects. The influences of the axial force, damping coefficient and load velocity on the beam response are studied. The limiting case of no damping and critial damping are also investigated. The profiles of the mement of the beam is shown graphically for several values of the load speed, the axial force and damping parameters.