• 제목/요약/키워드: Reaction parameter

검색결과 477건 처리시간 0.026초

The Growth Process of Interactive Virtual Life using Genetic Algorithm

  • Kwon, Min-Su;Kim, Do-Wan;Hoon Kang
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.89.2-89
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    • 2002
  • In this paper, we modeled a virtual life (VL) that react to the user's action according to its own behavioral characteristics and grows itself. We established some conditions with which such a VL is designed. Genetic Algorithm is used for the growth process that changes the VL's properties. In this process, the parameter values of the VL's properties are encoded as ore chromosome, and the GA operations change this chromosome. The VL's reaction to the user's action is determined by these properties as well as the general expectation of each reaction. These properties are evaluated through 5 fitness measures so as to deal with multi-objective criteria. Here, we pr...

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유연 구조물에서 반력 평가를 위해 요구되는 모드의 수 (On the Number of Modes Required to Observe Forces in Flexible Structures)

  • 김주형;김상섭
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.562-567
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    • 2001
  • The number of required modes to provide accurate force information in a truncated model of a flexible structure is investigated. In the case of modal truncation of a distributed parameter system, the difference in convergence rates between displacements and forces is discussed. The residual flexibility, a term from past literature, is used to recapture some of the lost force information in a truncated model. This paper presents numerical and experimental results of a study where the residual flexibility is used in conjunction with a Kalman filter so that accurate force information may be obtained from a small set of displacement measurements with a reduced-order model. The motivation for this paper is to be able to obtain accurate information about unmeasurable dynamic reaction forces in a rotating machine for diagnostic and control purposes.

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The Photoinactivation of Photosystem II in Leaves: A Personal Perspective

  • Chow, Wah-Soon
    • Journal of Photoscience
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    • 제8권2호
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    • pp.43-53
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    • 2001
  • a, a parameter that describes how effectively photoinactivated PS II units protect their functional neighbours; car, carotenoids; ΔpH, transthylakoid pH difference; D1 protein, psbA gene product in the PS II reaction centre; f, functional fraction of PS II: F$\_$v//F$\_$m/, the ratio of variable to maximum chlorophyll a fluorescence; k$\_$d/, rate coefficient for degradation of D1 protein; k$\_$i/ and k$\_$r/, rate coefficient for photoinactivation and repair of PS II, respectively; NADP+, oxidized nicontinamide adenine dinucleotide phosphate; P680, the primary electron donor in the PSII reaction centre; Ph, pheophytin; PS, photosystem; Q$\_$A/, first quinone acceptor of an electron in PS II; R$\_$s/, the gross rate of D1 protein synthesis.

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유연 구조물에서 반력 평가를 위해 요구되는 모드의 수 (On the Number of Modes Required to Observe Forces in Flexible Structures)

  • 김주형;김상섭
    • 한국정밀공학회지
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    • 제19권1호
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    • pp.150-157
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    • 2002
  • The number of required modes to provide accurate force information in a truncated model of a flexible structure is investigated. In the case of modal truncation of a distributed parameter system, the difference in convergence rates between displacements and forces is discussed. The residual flexibility. a term from past literature, is used to recapture some of the lost force information in a truncated model. This paper presents numerical and experimental results of a study where the residual flexibility is used in conjunction with a Kalman filter so that accurate force information may be obtained from a small set of displacement measurements wish a reduced-order model. The motivation for this paper is to be able to obtain accurate information about unmeasurable dynamic reaction forces in a rotating machine for diagnostic and control purposes.

희박 천연가스 자동차용 NOx 흡장촉매와 TWC의 NOx 반응특성 비교 (Comparison of NOx Reduction Characteristics of NOx Storage Catalyst and TWC for Lean-burn Natural Gas Vehicles)

  • 최병철;정우남;이춘희
    • 한국자동차공학회논문집
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    • 제12권5호
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    • pp.79-84
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    • 2004
  • We evaluated the reduction performance of NOx storage catalyst and TWC for lean-burn natural gas engine by the model gas. The method of unsteady state reaction was used to compare with reduction performances of NOx storage catalyst and TWC. It was found that the effective parameter was rich spike duration, temperature of the model gas. In the presence of $CO_2$ and $H_2O$ in the reaction mixture was decreased the NOx reduction performance.

Ethanol-Water 溶液內에서의 p-Nitrobenzyl Chloride의 Solvolysis (Solvolysis of p-Nitrobenzyl chloride in the Ethanol-water Mixtures)

  • 이억석
    • 대한화학회지
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    • 제10권1호
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    • pp.11-14
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    • 1966
  • Ethanol-water mixture 內에서 일어나는 p-nitrobenzyl chloride의 solvolysis反應에 대한 熱力學的 parameter를 구하고 이 data를 ${\delta}_M{\Delta}H^{\neq} = a'Y + b{\delta}_M{\Delta}S^{\leq}$에 適用함으로써 反應常數 a'가 50% 이하의 alcohol solvent에서나 50% 이상의 solvent에서 같다는 것을 알 수 있었다. 즉 water-rich solvent에서나 alcohol-rich solvent에서나 solvolysis反應의 mechanism은 변함이 없다는 것을 알았다.

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Styrene-Butadiene 무유화제 유화공중합에서의 아크릴계 친수성 공단량체의 영향 (The Effect of Various Hydrophilic Acrylic Comonomers on Soap-Free Emulsion Polymerization of Styrene-Butadiene Rubber)

  • 정희실;이창성;김병규;신영조
    • Elastomers and Composites
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    • 제28권4호
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    • pp.267-273
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    • 1993
  • A number of hydrophilic acrylic comonomers were incorporated into styrene-butadiene soap-free emulsion polymerization. It was found that reaction rate decreased according to : AN>AA>MMA>EA>IA>AAM>MA>HEMA. It was also observed that reaction rate increased with decreasing H-bonding factor contribution to the solubility parameter of the hydrophilic comonoer. The SBR latexes were very monodisperse with the particle size distribution of $1.03{\times}1.12$. Since growth rate is proportional to polymerization time, the difference in conversion rates between various comonomers was resulted from the particle number density of SBR latexes for the various hydrophilic comonomers. It was also found that the colloidal stability of the latexes was excellent because no external emulsifier was incorporated.

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Transition-State Variation in the Solvolyses of Phenyl Chlorothionoformate in Alcohol-Water Mixtures

  • 구인선;양기열;강대호;박혜진;강금덕;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제20권5호
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    • pp.577-580
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    • 1999
  • Solvolyses of phenyl chlorothionoformate in water, D2O, CH3OD, 50% D2O-CH3OD, and in aqueous binary mixtures of acetone, ethanol and methanol are investigated at 25.0℃. The Grunwald-Winstein plots of firstorder rate constants for phenyl chlorothionoformate with Ycl (based on 2-adamantyl chloride) show a dispersion phenomenon, and also the extended Grunwald-Winstein plots show a poor correlation for the solvolyses of phenyl chlorothionoformate. The ring parameter (I) has been shown to give considerable improvement when it is added as an hI term to the original and extended Grunwald-Winstein correlations. The dispersions in the Grunwald-Winstein correlations in the present studies are caused by the conjugation between the reaction center and the aromatic ring in the vicinity of the reaction center. This study has shown that the magnitude of l and m values associated with a change of solvent composition leads to predict the SN2 transition state. The kinetic solvent isotope effects determined in deuterated water and methanol are consistent with the proposed mechanism of the general base catalyzed SN2 mechanism.

Preparation and characterization of niobium carbide crystallites

  • Choi, Jeang-Gil
    • 한국결정성장학회지
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    • 제19권3호
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    • pp.125-129
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    • 2009
  • The preparation and characterization of niobium carbide crystallites were investigated in this study, and in particular, the effect of preparation conditions were studied on the synthesis of niobium carbides crystallites. For this purpose, various characterization techniques including x-ray diffraction, BET surface area, and oxygen uptake measurements were employed to characterize the synthesized niobium carbide crystallites. The niobium carbide crystallites were prepared using niobium oxide and methane gas or methane-hydrogen mixture. Using x-ray diffraction a lattice parameter of $4.45{\AA}$ and a crystallite size ranging from $52{\AA}$ to $580{\AA}$ was found. BET surface areas ranged from $3.2\;m^2/g$ to $16.6\;m^2/g$ and oxygen uptake values varied from $0.5{\mu}mol/g$ to $6.1{\mu}mol/g$. It was observed that niobium carbide crystallites were active for ammonia decomposition reaction. While the BET surface area increased with increasing the oxygen uptake, the conversion of ammonia decomposition reaction decreased. These results indicated that the ammonia decomposition over these materials was considered to be structure-sensitive.