• Title/Summary/Keyword: convergence free

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A STUDY ON INCOMPRESSIBLE FLOW COMPUTATIONS USING A HERMITE STREAM FUNCTION (Hermite 유동함수를 이용한 비압축성 유동계산에 대한 연구)

  • Kim, J.W.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.61-65
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    • 2006
  • This paper describes a recent development on the divergence free basis function based on a hermite stream function. The well-known cavity problem has been used to compare the accuracy and the convergence of the present method with those of a modified residual method known as one of the stabilized finite element methods. The comparison showed the present method performs better in the accuracy and convergence.

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Incompressible How Computations using a Hermite Stream Function (Hermite 유동함수를 이용한 비압축성 유동계산)

  • Kim, Jin-Whan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.411-414
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    • 2006
  • This paper describes a recent development on the divergence free basis function based on a hermite stream function. The well-known cavity problem has been used to compare the accuracy and the convergence of the present method with those of a modified residual method known as one of the stabilized finite e1ement methods. The comparison showed the present method performs better in the accuracy and convergence.

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A QUADRAPARAMETRIC FAMILY OF EIGHTH-ORDER ROOT-FINDING METHODS

  • Kim, Young Ik
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.1
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    • pp.133-143
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    • 2014
  • A new three-step quadraparametric family of eighth-order iterative methods free from second derivatives are proposed in this paper to find a simple root of a nonlinear equation. Convergence analysis as well as numerical experiments confirms the eighth-order convergence and asymptotic error constants.

A Study on the Convergence Characteristics Improvement of the Modified-Multiplication Free Adaptive Filer (변형 비적 적응 필터의 수렴 특성 개선에 관한 연구)

  • 김건호;윤달환;임제탁
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.6
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    • pp.815-823
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    • 1993
  • In this paper, the structure of modified multiplication-free adaptive filter(M-MADF) and convergence analysis are presented. To evaluate the performance of proposed M-MADF algorithm, fractionally spaced equalizer (FSE) is used. The input signals are quantized using DPCM and the reference signals is processed using a first-order linear prediction filter, and the outputs are processed by a conventional adaptive filter. The filter coefficients are updated using the Sign algorithm. Under the assumption that the primary and reference signals are zero mean, wide-sense stationary and Gaussian, theoretical results for the coefficient misalignment vector and its autocorrelation matrix of the filter are driven. The convergence properties of Sign. MADF and M-MADF algorithm for updating of the coefficients of a digital filter of the fractionally spaced equalizer (FSE) are investigated and compared with one another. The convergence properties are characterized by the steady state error and the convergence speed. It is shown that the convergence speed of M-MADF is almost same as Sign algorithm and is faster that MADF in the condition of same steady error. Especially it is very useful for high correlated signals.

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Biodegradation and Removal of PAHs by Bacillus velezensis Isolated from Fermented Food

  • Sultana, Omme Fatema;Lee, Saebim;Seo, Hoonhee;Al Mahmud, Hafij;Kim, Sukyung;Seo, Ahyoung;Kim, Mijung;Song, Ho-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.31 no.7
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    • pp.999-1010
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    • 2021
  • Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. They are highly toxigenic and carcinogenic. Probiotic bacteria isolated from fermented foods were tested to check their ability to degrade and/or detoxify PAHs. Five probiotic bacteria with distinct morphologies were isolated from a mixture of 26 fermented foods co-cultured with benzo(a)pyrene (BaP) containing Bushnell Haas minimal broth. Among them, B. velezensis (PMC10) significantly reduced the abundance of BaP in the broth. PMC10 completely degraded BaP presented at a lower concentration in broth culture. B. velezensis also showed a clear zone of degradation on a BaP-coated Bushnell Haas agar plate. Gene expression profiling showed significant increases of PAH ring-hydroxylating dioxygenases and 4-hydroxybenzoate 3-monooxygenase genes in B. velezensis in response to BaP treatment. In addtion, both live and heat-killed B. velezensis removed BaP and naphthalene (Nap) from phosphate buffer solution. Live B. velezensis did not show any cytotoxicity to macrophage or human dermal fibroblast cells. Live-cell and cell-free supernatant of B. velezensis showed potential anti-inflammatory effects. Cell-free supernatant and extract of B. velezensis also showed free radical scavenging effects. These results highlight the prospective ability of B. velezensis to biodegrade and remove toxic PAHs from the human body and suggest that the biodegradation of BaP might be regulated by ring-hydroxylating dioxygenase-initiated metabolic pathway.

A Study on Creating Barrier-Free Exhibition Appreciation Environment based on the Visually Impaired Person's Perspectives (시각장애인 당사자관점에 기초한 베리어프리 전시감상환경 연구)

  • Kim, Sun-Hee;Um, Myung-Yong;Lee, Eui-Bhin;Cho, Jun-Dong
    • Journal of the Korea Convergence Society
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    • v.10 no.8
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    • pp.265-276
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    • 2019
  • The purpose of this study was to explore the possibility of creating barrier-free exhibition-appreciation environment based on the visually impaired person's perspectives. Participants were selected by the purposeful sampling method. Researchers conducted a couple of in-depth interviews with four visually impaired persons. Yin's case study method was employed to analyze qualitative information. The analysis revealed nine sub-themes in two sections: three from 'accessibility within the exhibition room'; and six from 'demand for immersive exhibition environment.' Based on the results, following suggestions were presented: First, we need to provide quality information appropriate for artworks-appreciation; secondly, to ensure the visually impaired people to appreciate the culture and arts without any barrier, we need to extend certification of barrier-free living environment to exhibition-appreciation area. Finally, to facilitate these two tasks we need to encourage the convergence research among science and technology, humanities and society, and culture and arts.

Topology Characteristics and Generation Models of Scale-Free Networks

  • Lee, Kang Won;Lee, Ji Hwan
    • Journal of information and communication convergence engineering
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    • v.19 no.4
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    • pp.205-213
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    • 2021
  • The properties of a scale-free network are little known; its node degree following a power-law distribution is among its few known properties. By selecting real-field scale-free networks from a network dataset and comparing them to other networks, such as random and non-scale-free networks, the topology characteristics of scale-free networks are identified. The assortative coefficient is identified as a key metric of a scale-free network. It is also identified that most scale-free networks have negative assortative coefficients. Traditional generation models of scale-free networks are evaluated based on the identified topology characteristics. Most representative models, such as BA and Holme&Kim, are not effective in generating real-field scale-free networks. A link-rewiring method is suggested that can control the assortative coefficient while preserving the node degree sequence. Our analysis reveals that it is possible to effectively reproduce the assortative coefficients of real-field scale-free networks through link-rewiring.

Development of Meshless Method for Free Vibration Analysis of Arbitrarily Shaped Free Plates Using Local Polar Coordinates (지역 극좌표계를 이용한 임의 형상 자유단 평판의 자유진동해석을 위한 무요소법 개발)

  • Kang, Sang-Wook;Atluri, S. N.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.6
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    • pp.674-680
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    • 2008
  • A new meshless method for obtaining natural frequencies of arbitrarily shaped plates with the free boundary condition is introduced in the paper. In order to improve the characteristics of convergence and accuracy of the method, a special local polar coordinates system is devised and located for each of nodes distributed along the boundary of the plate of interest. In addition, a new way of decreasing the size of the system matrix that gives natural frequencies of the plate is employed to reduce the amount of numerical calculations, which is needed for computing the determinant of the system matrix. Finally the excellence of the characteristics of convergence and accuracy of the method is shown in several case studies, which indicate that natural frequencies by the proposed method are very accurate and converged swiftly to exact values as the number of boundary nodes increases.

An Error Correcting High Rate DC-Free Multimode Code Design for Optical Storage Systems (광기록 시스템을 위한 오류 정정 능력과 높은 부호율을 가지는 DC-free 다중모드 부호 설계)

  • Lee, June;Woo, Choong-Chae
    • Journal of the Institute of Convergence Signal Processing
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    • v.11 no.3
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    • pp.226-231
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    • 2010
  • This paper proposes a new coding technique for constructing error correcting high rate DC-free multimode code using a generator matrix generated from a sparse parity-check matrix. The scheme exploits high rate generator matrixes for producing distinct candidate codewords. The decoding complexity depends on whether the syndrome of the received codeword is zero or not. If the syndrome is zero, the decoding is simply performed by expurgating the redundant bits of the received codeword. Otherwise, the decoding is performed by a sum-product algorithm. The performance of the proposed scheme can achieve a reasonable DC-suppression and a low bit error rate.