• Title/Summary/Keyword: Ghost analysis

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Enhanced Equidistant Chosen Message Power Analysis of RSA-CRT Algorithm (RSA-CRT의 향상된 등간격 선택 평문 전력 분석)

  • Park, Jong-Yeon;Han, Dong-Guk;Yi, Ok-Yeon;Choi, Doo-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.2
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    • pp.117-126
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    • 2011
  • RSA-CRT algorithm is widely used to improve the performance of RSA algorithm. However, it is also vulnerable to side channel attacks like as general RSA. One of the power attacks on RSA-CRT, proposed by Boer et al., is a power analysis which utilizes reduction steps of RSA-CRT algorithm with equidistant chosen messages, called as ECMPA(Equidistant Chosen Messages Power Analysis) or MRED(Modular Reduction on Equidistant Data) analysis. This method is to find reduction output value r=xmodp which has the same equidistant patterns as equidistant messages. One can easily compute secret prime p from exposure of r. However, the result of analysis from a reduction step in [5] is remarkably different in our experiment from what Boer expected in [5]. Especially, we found that there are Ghost key patterns depending on the selection of attack bits and selected reduction algorithms. Thus, in this paper we propose several Ghost key patterns unknown to us until now, then we suggest enhanced and detailed analyzing methods.

A Simulation Method for Modeling the Morphology and Characteristics of Electrospun Polymeric Nanowebs

  • Kim Hyungsup;Kim Dae-Woong;Seo Moon Hwo;Cho Kwang Soo;Haw Jung Rim
    • Macromolecular Research
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    • v.13 no.2
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    • pp.107-113
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    • 2005
  • We developed an algorithm to simulate the generation of virtual nanowebs using the Monte Carlo method. To evaluate the pore size of the simulated multi-layered nanoweb, an estimation algorithm was developed using a ghost particle having zero volume and mass. The penetration time of the ghost particle through the virtual nanoweb was dependent on the pore size. By using iterative ghost particle penetrations, we obtained reliable data for the evaluation of the pore size and distribution of the virtual nanowebs. The penetration time increased with increasing number of layers and area ratio, whereas it decreased with increasing fiber diameter. Dimensional analysis showed that the penetration time can be expressed as a function of the fiber diameter, area ratio and number of layers.

A Study on Picture Quality Impairing Factors and Evaulation Method for The Video Signal in Urban Mobile Reception (영상신호의 시가지 이동수신에 의한 화상열화요인의 평가법에 관한 연구)

  • Deock Ho Ha
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.3
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    • pp.52-60
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    • 1993
  • Fluttering ghost which is the most severs picture impairment in mobile TV reception under multipath fading environments can be detected by measuring the dynamic variation of the synchronizing pulse timing. And also, the occurrence-stucture of fluttering ghost are directly correlated with the multipath parameters. This paper describes the quantitative evaluating method of the mobile TV pictures impaired by multipath parameters by means of the spectral analysis of synchronizing timing fluctuation. The ghost-flutter curve derived from the spatial amplitue spectrum of synchronizing pulse timing fluctuation express well the spatial variation characteristic, and it has been found to be the quantitative evaluating measure of picture impairment in mobile reception. A correspondence between the ghost-flutter curve (and/or index) and picture quality opinion test results is established.

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Characteristics of Dynamic Wave Propagation in Peridynamic Analysis with Nonlocal Ghost Interlayer (가상 층간 구조 페리다이나믹 해석의 파동 전파 특성 검토)

  • Ha, Youn Doh
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.4
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    • pp.257-263
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    • 2019
  • Multilayered structures include lamination by relatively thick plies and thin interlayers. For efficient peridynamic analysis of dynamic fracturing multilayered structures, the interlayer is modeled using ghost peridynamic particles while the ply is formulated via real peridynamics. With the nonlocal ghost interlayer, one may keep the discretization resolution low for the ply. In this study, the characteristics of dynamic wave propagation through the nonlocal ghost interlayer in peridynamic analysis are investigated. It is observed that the interlayer not only binds adjacent plies, but also significantly influences energy transfer between plies, and thereby their deformation and motion. In addition, near a surface or boundary, peridynamic particles do not have a full nonlocal neighborhoods. This causes the effective material properties near the surface to be different from those in the bulk. Surface correction based on neighborhood volumes is employed. The impact of surface correction on wave propagation in multilayered structures is investigated.

Consideration about 'Heaven and Man' from review and analysis of 'Heaven's Will', 'Verification of Ghost' and 'Indeterminism' of Mozi (묵자의 「천지(天志)」, 「명귀(明鬼)」 및 「비명(非命)」 편 분석을 통한 천인(天人)관계 고찰)

  • Hwang, SeongKyu
    • The Journal of Korean Philosophical History
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    • no.53
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    • pp.165-190
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    • 2017
  • This thesis is for the analysis of the relationships between Mozi's 'Heaven and Man' through the inspection of meaning and emphasis in his three books, 'Heaven's Will', 'Verification of Ghost' and 'Indeterminism'. According to the previous study, the Heaven's Will and Verification of Ghost are justify Mozi's theory of theistic stance with the Heaven's authority. And in case of the 'Indeterminism', there seems to be positive and rational way of awareness and it's thought to be atheistic stance. It is thought that there is a rule of action which is about the personality principle, and it suggest that how the government rule the country, and how the people lead a life. And it is the ghost that give prize or punishment when they did something according to this principle or not. So, men should do their best in actual life to meet the heaven's will. Because my fate is not decided by heaven's order but my own action. And it is thought that the main point of 'the indeterminism' is about Heaven helps those who do independent and active efforts. In short, 'the Heaven's Will', Verification of Ghost' and 'Indeterminism' are neither contradiction nor conversion form theism to atheism. Mozi is thought to divide clearly about ghost's works and people's works, and it is expressed explicitly in his works 'Heaven's Will', 'Verification of Ghost' and 'Indeterminism'.

Transformation of Edwardsiella tarda and Transcriptional Characteristics of E-lysis Gene in Recombinant Bacterial Ghosts (어류 병원성 세균 Edwardsiella tarda의 형질전환 및 재조합 ghost 세균에서의 E-lysis 유전자의 전사 발현 특징)

  • Kwon, Se Ryun;Nam, Yoon Kwon
    • Korean Journal of Ichthyology
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    • v.19 no.2
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    • pp.83-87
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    • 2007
  • Edwardsiella tarda, a gram (-) pathogen causing edwardsiellosis in farmed fish, was transformed via electroporation with a plasmid expression vector driving the PhiX174 E-lysis gene under the transcriptional control by lambda PR regulatory sequence. The persistent maintenance of the plasmid vector in recombinant E. tarda was found in numerous subculture procedures over up to 6 months without any adverse effect on the original copy number of plasmids. Comparative examination based on semi-quantitative RT-PCR analysis on transcriptional efficiency of E-lysis gene between recombinant E. coli and E. tarda indicated that promoter strength and induction capacity of bacterial ghosts would be retarded in E. tarda as compared to the E. coli. However, the completeness of induction for bacterial ghosts in E. tarda was the same with E. coli, in which at least 99.99% of induction rate was possible and further the viability of recombinant bacteria was completely eliminated by a post-induction procedure including washing and freeze drying lyophilization.

Performance Analysis of Data Association Applied Frequency Weighting in 3-Passive Linear Array Sonars (주파수 가중치를 적용한 3조의 수동 선배열 소나 센서의 정보 연관 성능 분석)

  • 구본화;윤제한;홍우영;고한석
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.2
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    • pp.109-116
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    • 2004
  • This paper deals with data association using 3 sets of passive linear array sonars (PUS) geometrically positioned in a Y-shaped configuration, but fixed in an underwater environment. The data association problem is directly transformed into a 3-D assignment problem, which is known to be NP-hard. For generic passive sensors, it can be sotted using conventional algorithms, while it in PLAS becomes a formidable task due to the presence of bearing ambiguity. In particular, we proposed data association method robust to bearing measurements errors by incorporating frequency information and analyze a region of ghost problem by geometrical relation PUS and target. We analyzed the effectiveness of the proposed method by representative simulation in multi-target.

An Analysis of the SYNC Timing Fluctuations in Mobile Visual Communication Urder Urban Multipath Propagation Environments (다중파 전파전파환경에서의 이동화상통신의 동기시간 변동량해석에 관한 연구)

  • 하덕호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.5
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    • pp.472-485
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    • 1989
  • This paper represents the occurrence structure of the timing variation of TV horizontal synchronizing pulse(H-sync pulse) in mobile TV reception. Fluttering ghost is caused by timing varations of the H-sync pulse and is due to frequency elective fading in a multipath propagation envoronment. H-sync timing fluctuations, and hence, fluttering ghost are directly correlated with the multipath parameters, i.e., H-sync timing fluctuations reflect well the severity of the multipath environment. The occurrence structure of H-sync timtng fluctuation is analysed theoretically in relation to the multipath environnment. The occurrence structure of H-sync timing fluctuation is analysed theoretically in relation to the multipath parameters, assuming the two-ray propagation model. The H-sync timing fluctuation occurs with the variation in relative phase and /or D/U variation of long-delayed multipath waves.

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Fast Noise Reduction Approach in Multifocal Multiphoton Microscopy Based on Monte-Carlo Simulation

  • Kim, Dongmok;Shin, Younghoon;Kwon, Hyuk-Sang
    • Current Optics and Photonics
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    • v.5 no.4
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    • pp.421-430
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    • 2021
  • The multifocal multiphoton microscopy (MMM) enables high-speed imaging by the concurrent scanning and detection of multiple foci generated by lenslet array or diffractive optical element. The MMM system mainly suffers from crosstalk generated by scattered emission photons that form ghost images among adjacent channels. The ghost image which is a duplicate of the image acquired in sub-images significantly degrades overall image quality. To eliminate the ghost image, the photon reassignment method was established using maximum likelihood estimation. However, this post-processing method generally takes a longer time than image acquisition. In this regard, we propose a novel strategy for rapid noise reduction in the MMM system based upon Monte-Carlo (MC) simulation. Ballistic signal, scattering signal, and scattering noise of each channel are quantified in terms of photon distribution launched in tissue model based on MC simulation. From the analysis of photon distribution, we successfully eliminated the ghost images in the MMM sub-images. If the priori MC simulation under a certain optical condition is established at once, our simple, but robust post-processing technique will continuously provide the noise-reduced images, while significantly reducing the computational cost.

Evaluation of Optimal Condition for Recombinant Bacterial Ghost Vaccine Production with Four Different Antigens of Streptococcus iniae-enolase, GAPDH, sagA, piaA (연쇄구균증 항원-enolase, GAPDH, sagA, piaA에 대한 재조합 고스트 박테리아 백신의 생산 최적화)

  • Ra, Chae-Hun;Kim, Yeong-Jin;Son, Chang-Woo;Jung, Dae-Young;Kim, Sung-Koo
    • Journal of Life Science
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    • v.19 no.7
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    • pp.845-851
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    • 2009
  • A vector harboring double cassettes; a heterologous gene expression cassette of pHCE-InaN-antigen and a ghost formation cassette of pAPR-cI-E lysis 37 SDM was constructed and introduced to E. coli DH5a. For the production of a bacterial ghost vaccine, bacterial ghosts from E. coli / Streptococcus iniae with four different types of antigens - enolase, GAPDH, sagA and piaA - were produced by the optimization of fermentation parameters such as a glucose concentration of 1 g/l, agitation of 300 rpm and aeration of 1 vvm. Efficiency of ghost bacteria formation was evaluated with cultures of OD$_{600}$=1.0, 2.0 and 3.0. The efficiency of the ghost bacteria formation was 99.54, 99.67, 99.99 and 99.99% with inductions at OD$_{600}$=3.0, 1.0, 2.0 and 1.0 for E. coli/S. iniae antigens enolase, piaA, GAPDH and sagA, respectively. Ghost bacteria as a vaccine was harvested by centrifugation. The antigen protein expressions were analyzed by SDS-PAGE and western blot analysis, and the molecular weights of the enolase, piaA, GAPDH and sagA were 78, 26, 67 and 26 kDa, respectively. The molecular weights of the expressed antigens were consistent with theoretical sizes obtained from the amino acid sequences.