• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.51-54
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• 2001

Recently Hwang and Li［1］ proposed a remote user authentication scheme using smart cards. Their scheme is based on the ElGamal public key cryptosystem and does not need to maintain a password table for verifying the legitimacy of the login users. In this paper, we proposed an advanced user authentication scheme using smart cards. Unlike Hwang and Li's scheme, smart card contains a pair of public parameters(h, P) where h is a hash function which is used in login phase. In result, we reduce one exponential computation frequency in login phase and two exponential computation frequencies in authentication phase with comparing the Hwang and Li's scheme. The proposed scheme not only provides the advantages as security of Hwang and Li's scheme, but also reduces computation cost.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3356-3366
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• 1999

Electric commerce system based on distributed mobile on object such as mobile agents need both precise identification and secure authentication scheme on remotemobile entities. In this paper, existing discrete logarithm based Schnorr like entity authentication schemes are improved by the analysis of performance and security on the bi-directional interactive proofs. And ElGamal like schemes are also proposed. Then, there are enhanced with oblivious transfer based mono-directional authentication schemes based on trusted third party for applying to the mobile agent based computing systems. Therefore, proposed schemes provide compatible performance and safety on mobile entity authentication process.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.476-478
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• 2003

정보 기술의 급속한 발전으로 스마트카드는 무선 통신, 공중전화 서비스, 전자 상거래, 교통 분야등 여러 활용 분야에서 사용되고 있으며 특히 현금이나 신용카드를 대체하는 결제수단으로 떠오르면서 우리 생활에 많은 변화를 일으키고 있다. 그러나 이러한 편리함 뒤에는 평소 우리가 생각하지 못했던 일들, 예컨대 개인 정보의 유출 등의 사고가 발생하여 시스템 안전에 대한 문제가 제기되고 있는 실정이다. 그동안 스마트카드를 이용한 원격 인증에 있어 ElGamal 알고리즘이나 해쉬 함수를 이용하여 시스템이 사용자를 인증하는 단방향 인증이 연구되어 왔으나, 기술의 발달로 시스템에 대한 위조가 가능해지면서 보다 강화된 보안의 필요성이 대두되었다. 본 논문에서는 이산대수와 해쉬 함수를 결합한 하이브리드 방식으로 스마트카드를 이용한 원격 사용자 양방향 인증을 설계하였다.

• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.1799-1816
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• 2013

Privacy preserving multiset union (PPMU) protocol allows a set of parties, each with a multiset, to collaboratively compute a multiset union secretly, meaning that any information other than union is not revealed. We propose efficient PPMU protocols, using multiplicative homomorphic cryptosystem. The novelty of our protocol is to directly encrypt a polynomial by representing it by an element of an extension field. The resulting protocols consist of constant rounds and improve communication cost. We also prove the security of our protocol against malicious adversaries, in the random oracle model.

• Journal of Astronomy and Space Sciences
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• v.34 no.1
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• pp.31-35
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• 2017

Optical observation is one of the most common techniques used for characterizing the physical properties of unknown objects and debris in space. This research presents measurements and properties of the new object 96019 from ground-based optical methods. Optical observations of this small object were performed using a charge-coupled device (CCD) camera and the Santel-500 telescope at the Zvenigorod Observatory. The orbital elements and physical properties of this object, such as area-to-mass ratio, have been determined. The results show that this small object has a low area-to-mass ratio, between 0.009 and $0.12m^2/kg$. The light curve of object 96019 is given: Over the time intervals, variations in brightness are analyzed and the maximum brightness was found to be 12.4 magnitudes. The observational results show that, this object brightens by about three magnitudes over a time span of three minutes. Based on these observations, the characteristics and physical properties of this object are discussed.

• Ocean Systems Engineering
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• v.3 no.2
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• pp.149-165
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• 2013

Tension leg platforms (TLP's) are highly nonlinear due to large structural displacements and fluid motion-structure interaction. Therefore, the nonlinear dynamic response of TLP's under hydrodynamic wave loading is necessary to determine their deformations and dynamic characteristics. In this paper, a numerical study using modified Morison Equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling effect between all degrees of freedom on the dynamic behavior of a TLP. The stiffness of the TLP was derived from a combination of hydrostatic restoring forces and restoring forces due to cables and the nonlinear equations of motion were solved utilizing Newmark's beta integration scheme. The effect of wave characteristics was considered.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.190-194
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• 2002

Multiplication in Galois Field GF(2/sup m/) is a primary operation for many applications, particularly for public key cryptography such as Diffie-Hellman key exchange, ElGamal. The current paper presents a new architecture that can process Montgomery multiplication over GF(2/sup m/) in m clock cycles based on cellular automata. It is possible to implement the modular exponentiation, division, inversion /sup 1)/architecture, etc. efficiently based on the Montgomery multiplication proposed in this paper. Since cellular automata architecture is simple, regular, modular and cascadable, it can be utilized efficiently for the implementation of VLSI.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.821-828
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• 2011

Design and synthesis of new 3,4-diarylpyrazole-1-carboxamide derivatives are described. Their antiproliferative activity against A375 human melanoma cell line was tested and the effect of substituents on the diarylpyrazole scaffold was investigated. The pharmacological results indicated that most of the synthesized compounds showed moderate activity against A375, compared with Sorafenib. On the other hand, compounds Ia, Ie, IIb, and IIh were more potent than Sorafenib. In addition, compound IIa was equipotent to Sorafenib. Among all of these derivatives, compound IIb which has diethylamino and phenolic moieties showed the most potent antiproliferative activity against A375 human melanoma cell line. Virtual screening was carried out through docking of the most potent compound IIb into the domain of V600E-b-Raf and the binding mode was studied.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3635-3639
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• 2012

A series of new diarylureas possessing aminoisoquinoline scaffold was synthesized, and their in vitro antiproliferative activity against A375P human melanoma cell line was tested. Compounds 1d, 1l, 1n, 1p, 1q, and 1t showed superior potency against A375P to Sorafenib. The highest potency was shown by compound 1p possessing 3,5-bis(trifluoromethyl)phenyl terminal ring with $IC_{50}$ value of $0.41{\mu}M$.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2480-2486
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• 2013

A new series of diarylamides and diarylureas having 2,3-dihydropyrrolo[3,2-b]quinoline scaffold was synthesized. Their in vitro antiproliferative activities were tested over NCI-60 cancer cell lines of nine different cancer types. Some target compounds showed good inhibition percentages over different cell lines. Among all the target compounds, compound 1f possessing 6,7-dimethoxy-2,3-dihydropyrrolo[3,2-b]quinoline nucleus, amide linker, and 4-chloro-3-(trifluoromethyl)phenyl terminal ring showed high selectivity against MCF7 and MDA-MB-468 breast cancer cell lines more than the other tested cell lines. Its inhibition percentages at $10{\mu}M$ concentration over those two cell lines were 84.97% and 87.13%, respectively.