• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1442-1450
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• 2017

In liquid metal fast breeder reactors, postulated failures of the plant protection system may lead to serious unprotected accidental consequences. Unprotected transients are generically categorized as transient overpower accidents and transient under cooling accidents. In both cases, core meltdown may occur and this can lead to a molten fuel coolant interaction (MFCI). The understanding of MFCI phenomena is essential for study of debris coolability and characteristics during post-accident heat removal. Sodium is used as coolant in liquid metal fast breeder reactors. Viewing inside sodium at elevated temperature is impossible because of its opaqueness. In the present study, a methodology to depict MFCI phenomena using a flat panel detector based imaging system (i.e., real time radiography) is brought out using a woods metal-water experimental facility which simulates the $UO_2-Na$ interaction. The developed imaging system can capture attributes of the MFCI process like jet breakup length, jet front velocity, fragmented particle size, and a profile of the debris bed using digital image processing methods like image filtering, segmentation, and edge detection. This paper describes the MFCI process and developed imaging methodology to capture MFCI attributes which are directly related to the safe aspects of a sodium fast reactor.

• Journal of Information Technology Applications and Management
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• 제18권3호
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• pp.61-72
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• 2011

Trust for the data created, processed and transferred on e-Science environments can be estimated with provenance. The information to form provenance, which says how the data was created and reached its current state, increases as data evolves. It is a heavy burden to trace and verify the massive provenance in order to trust data. On the other hand, it is another issue how to trust the verification of data with provenance. This paper proposes a fast and exact verification of inter-domain data transfer and data origin for e-Science environment based on PKI. The verification, which is called two-way verification, cuts down the tracking overhead of the data along the causality presented on Open Provenance Model with the domain specialty of e-Science environment supported by Grid Security Infrastructure (GSI). The proposed scheme is easy-applicable without an extra infrastructure, scalable irrespective of the number of provenance records, transparent and secure with cryptography as well as low-overhead.

• 한국가정과교육학회지
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• 제28권3호
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• pp.79-88
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• 2016

패스트푸드는 간단한 조리를 거쳐 신속히 제공되는 음식으로 정의하고 있는데, 어떤 종류의 음식을 패스트푸드로 분류할 수 있는지, 패스트푸드와 패스트푸드가 아닌 음식을 구분하는 특징은 무엇인지 분명하지 않다. 본 연구는 선행 연구에서 패스트푸드로 제시한 14종 음식을 대상으로 패스트푸드의 인정 여부를 조사하였으며, 패스트푸드 인정 여부를 결정하는 패스트푸드의 특징에 대하여 조사하였다. 남 여 고등학생 306명을 대상으로 설문조사를 실시하였으며, 그 결과를 분석하였다. 조사대상자는 패스트푸드가 맛있고 편리한 음식이지만 영양가가 낮은 음식 즉, 고지방, 저비타민 음식으로 평가하였다. 햄버거, 피자, 프라이드치킨, 라면, 핫도그는 80% 이상의 조사대상자가 패스트푸드로 인정하였으나, 떡볶이, 스파게티, 샌드위치, 김밥, 샐러드의 경우 패스트푸드 인정 비율이 50%에 미치지 못하였다. 패스트푸드의 5가지 특징 중 음식의 패스트푸드 인정 여부를 결정하는 가장 확실한 특징은 건강에 해로운 음식이었고, 가장 불확실한 특징은 신속한 제공과 저렴한 가격으로 조사되었다. 패스트푸드가 흔히 fast, cheap foods로 지칭되지만 조사대상 남 여 고등학생은 패스트푸드를 신속히 제공되는 값싼 음식으로 인식하지 않는다는 것을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.1997-2015
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• 2011

In this paper, we propose the enhanced network-based mobility management protocol, called enhanced proxy mobile ipv6 (E-PMIPv6), which can provide mobile nodes (MNs) with a fast and efficient mobility service in PMIPv6 domain. The proposed scheme can provide a fast and efficient mobility service to MNs and also the strength of network scalability and stability to an access network by proposing the dynamic virtual hierarchical network architecture. In addition, the pre-authentication procedure for an MN, based on the information of neighbor mobile access gateway (MAG) list in the enhanced-policy server (E-PS), is proposed to support seamless handover by reducing MN's handover latency. Through performance evaluations of numerical analyses and simulations, we have confirmed and verified the superiority of the proposed scheme compared to the conventional proxy mobile ipv6 (PMIPv6).

• 디지털콘텐츠학회 논문지
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• 제5권1호
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• pp.28-34
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• 2004

본 논문은 주파수 선택성 라이시안 페이딩 환경에서 직교 다중반송파 16 QAM 신호의 블록 오류율 성능을 알아보았다. 블록 오류율을 느린 페이딩과 빠른 페이딩의 경우로 나누어서 구하였는데 파라미터로서는 정규화 된 시간 지연 $(\gamma/T_S),$ 비트 에너지 대 잡음 전력비 $(E_b/N_0),$ 희망 신호 전력대 지연된 비희망 신호 전력비 (DUR)를 고려하였다. 오류정정개수가 t = 1, 2인 블록 부호를 사용하면 느린 페이딩보다 빠른 페이딩에서 성능 개선이 있음을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.643-646
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• 2005

We present new ramp-reset waveforms that realize fast addressing in AC-PDPs. These waveforms distort the distribution of wall charges on the surface of a phosphor layer: hence, the enhanced electric field helps to ignite a cell faster. They also reduce the black luminance: the divide of erasing ramp down discharges into two parts, i.e. a surface discharge and a vertical discharge, makes lower luminance.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.831-840
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• 2001

In this study, We introduce the process of web usage mining, which has lately attracted considerable attention with the fast diffusion of world wide web, and explain the web log data, which Is the main subject of web usage mining. Also, we illustrate some real examples of analysis for web log data and look into practical application of web usage mining for eCRM.

• 대한수학회지
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• 제45권1호
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• pp.177-196
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• 2008

Using the results on the coefficients of Hermite-Fej$\acute{e}$r interpolations in [5], we investigate convergence of Hermite and Hermite-$Fej{\acute{e}}r$ interpolation of order m, m=1,2,... in $L_p(0<p<{\infty})$ and associated product quadrature rules for a class of fast decaying even $Erd{\H{o}}s$ weights on the real line.

• 한국전자거래학회지
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• 제9권1호
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• pp.209-220
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• 2004

If protocol has fast operations and short key length, it can be efficient user authentication protocol. Lenstra and Verheul proposed XTR. XTR have short key length and fast computing speed. Therefore, this can be used usefully in complex arithmetic. In this paper, to design efficient user authentication protocol we used a subgroup of Galois Field to problem domain. Proposed protocol does not use GF(p/sup 6/) that is existent finite field, and uses GF(p²) that is subgroup and solves problem. XTR-ElGamal based user authentication protocol reduced bit number that is required when exchange key by doing with upside. Also, proposed protocol provided easy calculation and execution by reducing required overhead when calculate. In this paper, we designed authentication protocol with y/sub i/ = g/sup b.p/sup 2(i-1)//ㆍv mol q, 1(equation omitted) 3 that is required to do user authentication.

• BMB Reports
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• 제30권4호
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• pp.253-257
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• 1997

Negative ion fast atom bombardment (FAB) mass spectra were found to allow the determination of the linkage positions in a series of underivatized linkage-isomeric oligosaccharides. A previous work (Laine et al., 1988) reported that ion patterns of linkage-isomeric trisaccharides could be distinguished by a positive ion. Negative ion FAB collison-activated dissociation (CAD) mass spectrometry (MS) spectra of trisaccharides exhibited better sensitivity than the positive ion mode and provided specific fragmentation patterns according to the linkage positions. Especially, the fragmentations, m/z 205 in F6 and m/z 221 in G6, not occuring in 1-3 or 1-4 linkage. were an indication of 1-6 linkage, by changing collision energies from + 10 eV to +60 eV. The survival ratios of molecular ions in each collision energy set gave support to previous results in which the order of bond stability was 1-6>1-4>1-3 linkage.