• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.173-176
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• 2004

전 세계적으로 안전한 데이터의 송수신에 대한 많은 연구가 지속되어 왔다. IPsec은 IP 패킷에 대해 기밀성과 무결성 그리고 인증과 같은 보안 서비스를 제공하는 국제 표준 프로토콜이며 IPsec의 키 관리 메커니즘이 IKE이다. 기존 IKE는 시스템간의 상호 운용성이 떨어질 뿐만 아니라 시스템의 성능을 저하시키며 서비스 거부 공격(DoS)에 대해 매우 취약한 구조를 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해서 기존 IKE 프로토콜에서 사용되지 않는 모드를 삭제하고 인증 방법을 전자서명과 공유된 비밀키에 기반한 방식으로 단일화시켰다. 또한 DoS 공격을 예방할 수 있도록 단순화된 IKE 프로토콜을 구현하고 테스트하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.647-649
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• 2003

인터넷의 폭발적인 성장으로 인터넷을 사용하는 사용자 및 애플리케이션들이 급속하게 등장하였다. 그로 인하여, 스트리밍 서비스 또는 time-sensitive한 애플리케이션들의 QoS를 보장하기 위한 여러 가지 QoS 연구들이 진행중이다. 시스코를 중심으로 한 기업망에서의 Policy Networking 기반의 서비스들이 점점 더 발전되어가고 있다. 즉, 시스코 라우터에서는 이를 지원하기 위한 filtering, Coloring, Policy 등의 명령어를 지원하게 되었다. 그러므로, 이것들을 운영하는 관리자들은 Dos 정책을 자동으로 분배, 적용, 모니터링, 리포팅 기능을 제공하는 자동화된 네트웍 관리도구들에 대한 요구들이 증가하고 있다. 시중에 나와 있는 시스코 제품들은 가격이 너무 비싸고, 관리자들의 요구 사항과는 약간의 거리감이 있다. 따라서, 이 논문에서 시스코 라우터 기반의 자동화된 QoS 정책 분배 시스템의 설계 및 구현 결과를 소개하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.426-428
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• 2014

최근 급속도로 기술이 발전하면서 스마트폰, 태블릿 등 스마트 기기의 보급률이 늘어나고 있다. 스마트TV, 스마트청소기, 스마트세탁기 등 가정에서 사용하는 가전제품으로 그 영역이 늘어나고 있는데 특히 Smart TV의 보급률이 늘어나고 있다. 네트워크인터페이스의 제공과 USB를 통한 펌웨어 업데이트 등 SmartTV의 기능적인 측면 때문에 Smart TV 대한 Dos공격부터 펌웨어 취약점 공격 등의 여러 형태의 보안문제가 발생하고 있다. 본 논문에서는 Smart TV시장에서의 점유율 1위를 기록하고 있는 Samsung SmartTV의 구조 및 보안문제 동향을 분석해 본다.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.139-145
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• 1994

The DOS, COOP and O 1s binding energy are calculated for Ni24(100) model surface with oxygen adsorbed on it. The calculation is made with PC/386 using the program obtained by converting EHMACC(VAX version) into PC version. The calculation shows the dissociative adsorption of oxygen molecule, of which the main cause is attributed to the transfer of the $d{\pi}$ and $d{\delta}$ electrons of Ni to the antibonding $1{\pi}_g$ of oxygen molecule. The O ls shift on the adsorption is calculated using the valence potential method, and the results agree fairly good with the experimental values.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.836-841
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• 1994

The polymer matrix effect on the selectivity, response rate and reproducibility for coextraction type anion-selective optode membranes were investigated with DOA-plasticized PVC, PVC/hydroxylated PVC, PU/hydroxylated PVC and DOS-plasticized CTA matrices. Optode membranes were prepared with TDMACl and ETH2412 dissolved in one of the four solvent polymeric matrices. The PU/hydroxylated PVC and PVC-based membranes have almost the same selectivity coefficients, while the CTA-based membrane is more selective toward lipophilic anions. The membrane with PU/hydroxylated PVC adhered strongly to a glass surface, and showed highly reproducible and relatively rapid response. Very poor adhesion of PVC/hydroxylated PVC and CTA-based membranes limited the usability of those membranes as sensor components. Based on these results, and considering the biocompatibility for clinical samples, the optode made with PU/hydroxylated PVC was applied to determine the thiocyanate ion in human saliva. The results obtained with this simple device were comparable to those with rather complicated ISE methods.

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.367-375
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• 1992

The electronic structure change caused by insertion of hydrogen into the interstices of Pd cluster is studied. Several properties such as energy, reduced overlap population (ROP), electon density (ED) and density of states (DOS) are calculated by Extended Huckel Method. Various types of clusters are considered. The same is performed on Ni and Pt and all the results are compared. The results show that the hydrogen atom in Pd is stabilized remarkably but its wave function is almost unperturbed. The fact is compatible with noticeable solubility of hydrogen in Pd but may not be a positive enough evidence to rationalize the claimed cold fusion phenomenon. It is also found that a remarkable charge transfer from Pd atom to hydrogen atom occurs.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1093-1097
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• 1994

The interaction of oxygen molecule with Ni44(111) model surface to which the molecule approaches is studied by calculating the relevant DOS and COOP with the tight-binding EHT method. It is found that the dissociative adsorption of oxygen takes place as a result of electron transfer from the Ni d${\pi}$ orbital to the antibonding 1${\pi}_g$ orbital of the oxygen molecule. This finding is noteworthy to contrast with the case of Ni(100) surface in which the electron transfer takes place from the Ni d${\delta}$ orbital of the nickel surface.

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1345-1349
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• 2001

New quadruply-bridged calix[6]arenes (I-V) have been studied as cesium selective ionophores in poly(vinyl chloride) (PVC) membrane electrodes. PVC membranes were prepared with dioctyl sebacate (DOS) or 2-nitrophenyl octyl ether (o-NPOE) as the sol vent mediator and potassium tetrakis(p-chlorophenyl)borate as the lipophilic salt additive. These ionophores produced electrodes with near-Nernstian slope. The selectivity coefficients for cesium ion with respect to alkali, alkaline earth and ammonium ions have been determined. The lowest detection limit (logaCs+ = -6.3) and the higher selectivity coefficient (logkpotCs+,Rb+ = -2.1 by SSM, -2.3 by FIM for calix[6]arene I) for Cs+ have been obtained for membranes containing quadruply-bridged calix[6]arenes (I, Ⅱ, Ⅲ), which have no para t-butyl substituents on the bridging benzene ring.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.499-502
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• 2008

This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation To understand the diversity and applicability of this tool an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 iterated under the same input parameters. Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. C++ compiler was chosen as a tool of use due to its availability, ease of use, ability to compute functions faster and uniquely possible to make a stand alone GUI executable in DOS mode. The program is developed in such a way that given the ambient flight conditions, burner exit temperature and several geometry areas the program generates its own input values used in the succeeding stations. A close resemblance of output values that define performance and thermodynamic state of the engine was realized between GASTURB 9 and using this code made from C++ compiler.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.63-70
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• 1995

Most of small-to-medium sized companies use computer to manage and control their manufacturing system. However, it is real hard to find a company which uses the system properly. There are several reasons. First of all, appropriate software to satisfy user's needs is not available and there is lack of mind to computerize. Therefore, this paper focuses to show difficulties which they will encounter, develop a model of computerized production management system and define proper level of computerization. An experimental system has been developed for an auto-parts manufacturing company using IBM-PC in the environment of MS-DOS and CA-Clipper.