• Title/Summary/Keyword: B-evolution

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HELMHOLTZ DECOMPOSITION AND SEMIGROUP THEORY TO THE FLUID AROUND A MOVING BODY

  • Bae, Hyeong-Ohk
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.3
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    • pp.661-676
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    • 2020
  • To understand the interaction of a fluid and a rigid body, we use the concept of B-evolution. Then in a similar way to the usual Navier-Stokes system, we obtain a Helmholtz type decomposition. Using B-evolution theory and the decomposition, we work on the semigroup to analyze the linear part of the system.

SOME PROPERTIES OF EVOLUTION ALGEBRAS

  • Camacho, L.M.;Gomez, J.R.;Omirov, B.A.;Turdibaev, R.M.
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.5
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    • pp.1481-1494
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    • 2013
  • The paper is devoted to the study of finite dimensional complex evolution algebras. The class of evolution algebras isomorphic to evolution algebras with Jordan form matrices is described. For finite dimensional complex evolution algebras the criterium of nilpotency is established in terms of the properties of corresponding matrices. Moreover, it is proved that for nilpotent $n$-dimensional complex evolution algebras the possible maximal nilpotency index is $1+2^{n-1}$.

Ethane Evolution in Cucumber Plants by Air Pollutants in Relation to Plants Injury (대기오염 물질 처리에 의한 오이 장해와 에탄 생성)

  • Bae, Gong-Young
    • Korean Journal of Environmental Agriculture
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    • v.17 no.2
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    • pp.127-131
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    • 1998
  • Ethane was measured to know whether active oxyzens may induce phytoxicity in stressedcucumber plant.The time course of the increase in ethane evolution was the same as that of the increase of visible injury in all treatments except $SO_2$ treatment.This result showed that air pollutants-induced plant damages were closely related to ethane evolution.And evolution of ethane was more increased in combined stress than singly one,suggesting that phytotoxicity was more severe in complex sterss.Also, evolution of ethane was enhanced in the light condition and scavengers of active oxygen were inhibited,showing that plant damage that plant damage were cause by active oxygens.

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BINARY STARS AND CLUSTERS AS TESTS OF STELLAR EVOLUTION MODELS

  • ANDERSEN J.;NORDSTROM B.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.239-240
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    • 1996
  • Precise masses, radii, and luminosities from eclipsing binaries and colour-magnitude diagrams for open clusters are classic tools in empirical tests of stellar evolution models. We review the accuracy and completeness required for such data to discriminate between current models and describe some recent. results with implications for convection theory.

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Design of multi-layered surface plasmon resonance sensors using optical admittance method and evolution algorithm (광학 어드미턴스 기법과 진화 알고리즘 기법을 이용한 다층 표면 플라즈몬 공명 센서의 설계)

  • Jung, Jae-Hoon;Lee, Seung-Ki
    • Journal of Sensor Science and Technology
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    • v.14 no.6
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    • pp.402-408
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    • 2005
  • This paper describes the optimal design of a multi-layered surface plasmon resonance sensors to meet various specifications and improve some physical parameters. Dip 3 dB bandwidth and depth were chosen as design parameters and the objective function was the norm of the difference between design parameters and target values. The design variables are thicknesses of each layer and to obtain the design parameters, the optical admittance method was employed. The (1+1) evolution strategy was employed as an optimization tool. By applying the proposed optimization procedure to a 3-layered sensor, the optimized design variables considerably improved the 3 dB bandwidth by 4.8 nm and the dip depth by 1.1 dB.

In Vitro Evolution of Lipase B from Candida antarctica Using Surface Display in Hansenula polymorpha

  • Kim, So-Young;Sohn, Jung-Hoon;Pyun, Yu-Ryang;Yang, In-Seok;Kim, Kyung-Hyun;Choi, Eui-Sung
    • Journal of Microbiology and Biotechnology
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    • v.17 no.8
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    • pp.1308-1315
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    • 2007
  • Lipase B from Candida antarctica (CalB) displayed on the cell surface of H. polymorpha has been functionally improved for catalytic activity by molecular evolution. CalB was displayed on the cell surface by fusing to a cell-wall anchor motif (CwpF). A library of CalB mutants was constructed by in vivo recombination in H. polymorpha. Several mutants with increased whole-cell CalB activity were acquired from screening seven thousand transformants. The two independent mutants CalB 10 and CalB 14 showed an approximately 5 times greater whole-cell activity than the wild-type. When these mutants were made as a soluble form, CalB 10 showed 6 times greater activity and CalB 14 showed an 11 times greater activity compared with the wild-type. Sequence analyses of mutant CALB genes revealed amino acid substitutions of $Leu^{278}Pro$ in CalB10 and $Leu^{278}Pro/Leu^{219}Gln$ in CalB14. The substituted $Pro^{278}$ in both mutants was located near the proline site of the ${\alpha}$10 helix. This mutation was assumed to induce a conformational change in the ${\alpha}$10 helix and increased the $k_{cat}$ value of mutant CalB approximately 6 times. Site-directed mutagenized CalB, LQ ($Leu^{219}Gln$) was secreted into the culture supernatant at an amount of approximately 3 times more without an increase in the CalB transcript level, compared with the wild-type.

Intensity Information and Curve Evolution Based Active Contour Model (밝기 정보와 곡선전개 기반의 활성 모델)

  • Kim, Seong-Kon
    • The KIPS Transactions:PartB
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    • v.10B no.5
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    • pp.521-526
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    • 2003
  • In this paper, we propose a geometric active contour model based on intensity information and curve evolution for detecting region boundaries. We put boundary extraction problem as the minimization of the difference between the average intensity of the region and the intensity of the expanding closed curves. We used level set theory to implement the curve evolution for optimal solution. It offered much more freedom in the initial curve position than a general active contour model. Our methods could detect regions whose boundaries are not necessarily defiened by gradient compared to general edge based methods and detect multiple boundaries at the same time. We could improve the result by using anisotropic diffusion filter in image preprocessing. The performance of our model was demonstrated on several data sets like CT and MRI medical images.

Improvement of Photoheterotrophic $H_2$ production of Rhodobacter sphaeroides by Removing Ammonium Ion Effect Exerted on Nitrogenase (Rhodobacter sphaeroides의 질소고정효소에 미치는 암모니움 이온 효과 제거를 통한 수소생성 증진)

  • Jin, Sang-Hoon;Kim, Mi-Sun;Lee, Jeong-Kug
    • KSBB Journal
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    • v.20 no.6
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    • pp.418-424
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    • 2005
  • Photoheterotrophic evolution of molecular hydrogen by Rhodobacter sphaeroides is mediated by nitrogenase that is regulated transcriptionally and post-translationally by ammonium ion. Two PII-like proteins, GlnB and GlnK, play key roles in mediating inhibition and repression of nitrogenase in the presence of ammonium ion. glnB and glnK of R. sphaeroides were interrupted to abolish the ammonium ion effect controlling nitrogenase. Ammonium ion effect was still observed in mutant having an interruption in either glnB or glnK. However, the nitrogenase activity of glnB-glnK double mutant is not affected by ammonium ion. $H_2$ evolution was improved by increasing gene dosages of nitrogenase-coding genes, nifHDK in trans in glnB-glnK double mutant.