• Title/Summary/Keyword: Negative Sequence

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Molecular identification of coagulase-negative staphylococci by rpoB sequence typing (rpoB 염기서열 분석을 이용한 응고효소 음성 포도알세균 분자 동정)

  • Seong, Won-Jin;Kim, Danil;Kim, Eun-Kyung;Ko, Dae-Sung;Ro, Younghye;Kim, Jae-Hong;Kwon, Hyuk-Joon
    • Korean Journal of Veterinary Research
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    • v.58 no.1
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    • pp.51-55
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    • 2018
  • Bovine mastitis (BM) has resulted in enormous economic loss in the dairy industry and coagulase-negative staphylococci (CNS) have caused subclinical BM. Although VITEK 2 GP ID card (VITEK 2) has been used for CNS identification, the probability of identification varies. The rpoB sequence typing (RSTing) method has been used for molecular diagnosis and epidemiology of bacterial infections. In this study, we undertook RSTing of CNS and compared the results with those of VITEK2 and 16S rRNA gene sequencing. As compared VITEK2, the molecular-based methods were more reliable for species identification; moreover, RSTing provided more molecular epidemiological information than that from 16S rRNA gene sequencing.

Functional Role of a Conserved Sequence Motif in the Oxygen-dependent Degradation Domain of Hypoxia-inducible Factor 1α in the Recognition of p53

  • Chi, Seung-Wook
    • Genomics & Informatics
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    • v.6 no.2
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    • pp.72-76
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    • 2008
  • Hypoxia-inducible factor $1{\alpha}\;(HIF1{\alpha})$ is a transcription factor that plays a key role in the adaptation of cells to low oxygen stress and oxygen homeostasis. The oxygen-dependent degradation (ODD) domain of $HIF1{\alpha}$ is responsible for the negative regulation of $HIF1{\alpha}$ in normoxia. The interactions of the $HIF1{\alpha}$ ODD domain with partner proteins such as von Hippel-Lindau tumor suppressor (pVHL) and p53 are mediated by two sequence motifs, the N- and C-terminal ODD(NODD and CODD). Multiple sequence alignment with $HIF1{\alpha}$ homologs from human, monkey, pig, rat, mouse, chicken, frog, and zebrafish has demonstrated that the NODD and CODD motifs have noticeably high conservation of the primary sequence across different species and isoforms. In this study, we carried out molecular dynamics simulation of the structure of the $HIF1{\alpha}$ CODD motif in complex with the p53 DNA-binding domain (DBD). The structure reveals specific functional roles of highly conserved residues in the CODD sequence motif of $HIF1{\alpha}$ for the recognition of p53.

Virtual Flux and Positive-Sequence Power Based Control of Grid-Interfaced Converters Against Unbalanced and Distorted Grid Conditions

  • Tao, Yukun;Tang, Wenhu
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1265-1274
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    • 2018
  • This paper proposes a virtual flux (VF) and positive-sequence power based control strategy to improve the performance of grid-interfaced three-phase voltage source converters against unbalanced and distorted grid conditions. By using a second-order generalized integrator (SOGI) based VF observer, the proposed strategy achieves an AC voltage sensorless and grid frequency adaptive control. Aiming to realize a balanced sinusoidal line current operation, the fundamental positive-sequence component based instantaneous power is utilized as the control variable. Moreover, the fundamental negative-sequence VF feedforward and the harmonic attenuation ability of a sequence component generator are employed to further enhance the unbalance regulation ability and the harmonic tolerance of line currents, respectively. Finally, the proposed scheme is completed by combining the foregoing two elements with a predictive direct power control (PDPC). In order to verify the feasibility and validity of the proposed SOGI-VFPDPC, the scenarios of unbalanced voltage dip, higher harmonic distortion and grid frequency deviation are investigated in simulation and experimental studies. The corresponding results demonstrate that the proposed strategy ensures a balanced sinusoidal line current operation with excellent steady-state and transient behaviors under general grid conditions.

Analysis of Sequence Impedances of 345kV Cable Transmission Systems (실계통 345kV 지중송전선 대칭좌표 임피던스의 해석)

  • Choi, Jong-Kee;Ahn, Yong-Ho;Yoon, Yong-Beum;Oh, Sei-Ill;Kwa, Yang-Ho;Lee, Myoung-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.905-912
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    • 2013
  • Power system fault analysis is commonly based on well-known symmetrical component method, which describes power system elements by positive, negative and zero sequence impedance. In case of balanced fault, such as three phase short circuit, transmission line can be represented by positive sequence impedance only. The majority of fault in transmission lines, however, is unbalanced fault, such as line-to-ground faults, so that both positive and zero sequence impedance is required for fault analysis. When unbalanced fault occurs, zero sequence current flows through earth and skywires in overhead transmission systems and through cable sheaths and earth in cable transmission systems. Since zero sequence current distribution between cable sheath and earth is dependent on both sheath bondings and grounding configurations, care must be taken to calculate zero sequence impedance of underground cable transmission lines. In this paper, conventional and EMTP-based sequence impedance calculation methods were described and applied to 345kV cable transmission systems (4 circuit, OF 2000mm2). Calculation results showed that detailed circuit analysis is desirable to avoid possible errors of sequence impedance calculation resulted from various configuration of cable sheath bonding and grounding in underground cable transmission systems.

A Gram-negative halophilic carotenoid-producing bacterium, Paracoccus sp.

  • Lee, Jae-Hyung;Lee, Won-Jae;Kim, Young-Tae
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.710-712
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    • 2003
  • A new species of Gram-negative halophilic cartenoid producing bacterium was isolated from the Haeundae Coast, Korea. This strain is non-motile, aerobic, orange-pigmented, rod-shaped, and produced carotenoids, mainly astaxanthin. All the type strains of the genus Paracoccus were compared with this strain using 16S rDNA sequence analysis, fatty acid patterns, and physiological reaction profiles. From the results obtained, this strain is classified as a new species, Paracoccus sp..

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On the strong law of large numbers for pairwise negative quadrant dependent random variables

  • T. S.;J. I.;H. Y.
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.291-296
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    • 2000
  • Petrov(1996) examined the connection between general moment conditions and the applicability of the strong law lf large numbers to a sequence of pairwise independnt and identically distributed random variables. In this note wee generalize Theorem 1 of Petrov(1996) and also show that still holds under assumption of pairwise negative quadrant dependence(NQD).

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A Robust PLL of PCS for Fuel Cell System under Unbalanced Grid Voltages (불평형 계통전압에 강인한 연료전지용 전력변환시스템의 PLL 방법)

  • Kim, Yun-Hyun;Kim, Wang-Rae;Lim, Chang-Jin;Kim, Kwang-Seob;Kwon, Byung-Ki;Choi, Chang-Ho
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.103-105
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    • 2008
  • In grid-interconnection system, a fast, robust and precise phase angle detector is most important to grid synchronization and the active power control. The phase angle can be easily estimated by synchronous dq PLL system. On the other hand under unbalanced voltage condition, synchronous dq PLL system has problem that harmonics occur to phase angle or magnitude of grid voltage because of the effect of the negative sequence components. So, To eliminate the negative sequence components, the PLL method using APF (All Pass Filter) in a stationery reference frame to extract positive sequence components under unbalanced voltage condition is researched. In this paper, we propose a new PLL method with decoupling network using APF in a synchronous reference frame to extract the positive sequence components of the grid voltage under unbalanced grid. The cut-off frequency of APF in a synchronous reference frame can be set to twice of the fundamental frequency comparing with that of APF in a stationery reference frame which is the fundamental frequency. The proposed PLL strategy can detect the phase angle quickly and accurately under unbalanced gird voltages. Simulation and experimental results are presented to verify the proposed strategy under different kind of voltage dips.

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A Note on Spliced Sequences and A-density of Points with respect to a Non-negative Matrix

  • Bose, Kumardipta;Sengupta, Sayan
    • Kyungpook Mathematical Journal
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    • v.59 no.1
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    • pp.47-63
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    • 2019
  • For $y{\in}{\mathbb{R}}$, a sequence $x=(x_n){\in}{\ell}^{\infty}$, and a non-negative regular matrix A, Bartoszewicz et. al., in 2015, defined the notion of the A-density ${\delta}_A(y)$ of the indices of those $x_n$ that are close to y. Their main result states that if the set of limit points of ($x_n$) is countable and density ${\delta}_A(y)$ exists for any $y{\in}\mathbb{R}$ where A is a non-negative regular matrix, then ${\lim}_{n{\rightarrow}{\infty}}(Ax)_n={\sum}_{y{\in}{\mathbb{R}}}{\delta}_A(y){\cdot}y$. In this note we first show that the result can be extended to a more general class of matrices and then consider a conjecture which naturally arises from our investigations.

A Hybird Antibody Model Design using Genetic Algorithm Scheme (유전 알고리즘 기법을 이용한 HA 모델 설계)

  • Shin, Mi-Yea;Jeon, Seoung-Heup;Lee, Sang-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.10
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    • pp.159-166
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    • 2009
  • A nature immunity system responds sensitively to an external invasion with various functions in a lot of bodies, besides it there is a function to remember information to have been currently infected. we propose a hybrid model similar to immune system which combine with the antibody which applied genetic algorithm as select antibody and the arbitrary abnormal system call sequence that applied negative selection of a nature immunity system. A proposed model uses an arbitrary abnormal system Kol sequence in order to reduce a positive defect and a negative defect. Data used to experiment are send mail data processed UNM (University of New Maxico). The negative defect that an experiment results proposal model judged system call more abnormal than the existing negative selection to normal system call appeared 0.55% low.