• Title/Summary/Keyword: Transition-state

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Design and Implementation of High-Speed Pattern Matcher in Network Intrusion Detection System (네트워크 침입 탐지 시스템에서 고속 패턴 매칭기의 설계 및 구현)

  • Yoon, Yeo-Chan;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11B
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    • pp.1020-1029
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    • 2008
  • This paper proposes an high speed pattern matching algorithm and its implementation. The pattern matcher is used to check patterns from realtime input packet. The proposed algorithm can find exact string, range of string values, and combination of string values from input packet at high speed. Given string and rule set are modelled as a state transition graph which can find overlapped strings simultaneously, and the state transition graph is partitioned according to input implicants to reduce implementation complexity. The pattern matcher scheme uses the transformed state transition graph and input packet as an input. The pattern matcher was modelled and implemented in VHDL language. Experimental results show the proprieties of the proposed approach.

Kinetics and Mechanism of the Aminolysis of Phenacyl Bromides in Acetonitrile. A Stepwise Mechanism with Bridged Transition State

  • Lee, Ik-Choon;Lee, Hai-Whang;Yu, Young-Kab
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.993-998
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    • 2003
  • In the aminolysis of phenacyl bromides (YC6H4COCH2Br) with benzylamines (XC6H4CH2NH2) in acetonitrile, the Bronsted βx (βnuc) values observed are rather low ( βX = 0.69-0.73). These values are similar to those (βx =  0.7) for other aminolysis reactions of phenacyl compounds with anilines and pyridines, but are much smaller than those ( βx = 1.1-2.5) for the aminolysis of esters with benzylamines which are believed to proceed stepwise with rate-limiting expulsion of the leaving group. The relative constancy of the βx values (βx =  0.7) irrespective of the amine, leaving group and solvent can be accounted for by a bridged type transition state in the rate-limiting expulsion of the leaving group. Thus the aminolysis of phenacyl derivatives are proposed to proceed stepwise through a zwitterionic tetrahedral intermediate (T±), with rate-limiting expulsion of the leaving group from T±. In the transition state, the amine is bridged between the carbonyl and α-carbons, which leads to negligible effect of amine on the leaving group expulsion rate.

Two-dimensional nonconforming finite elements: A state-of-the-art

  • Choi, Chang-Koon;Kim, Sun-Hoon;Park, Young-Myung;Chung, Keun-Young
    • Structural Engineering and Mechanics
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    • v.6 no.1
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    • pp.41-61
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    • 1998
  • A state-of-the-art report on the new finite elements formulated by the addition of nonconforming displacement modes has been presented. The development of a series improved nonconforming finite elements for the analysis of plate and shell structures is described in the first part of this paper. These new plate and shell finite elements are established by the combined use of different improvement schemes such as; the addition of nonconforming modes, the reduced (or selective) integration, and the construction of the substitute shear strain fields. The improvement achieved may be attributable to the fact that the merits of these improvement techniques are merged into the formation of the new elements in a complementary manner. It is shown that the results obtained by the new elements give significantly improved solutions without any serious defects such as; the shear locking, spurious zero energy mode for the linear as well as nonlinear benchmark problems. Recent developments in the transition elements that have a variable number of mid-side nodes and can be effectively used in the adaptive mesh refinement are presented in the second part. Finally, the nonconforming transition flat shell elements with drilling degrees of freedom are also presented.

Substituent Effects on the Leaving Groups in Benzyl Arenesulfonates (Benzyl Arenesulfonate의 離脫基의 置換基效果에 關한 硏究 (第 1 報))

  • Yoh Soo Dong
    • Journal of the Korean Chemical Society
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    • v.19 no.2
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    • pp.116-122
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    • 1975
  • Determination has been made of the kinetics of the reaction of benzyl arenesulfonates with pyridine in acetone. The substituent effects of the leaving groups in benzyl arenesulfonates are correlated by Hammett equations, with the exception of p-MeO and pNO2 groups, where the electron attracting substituents in the benzyl arenesulfonate increase the rate. The substituent effects of the leaving groups are as expected due to the nucleophilic attack of amine on the benzyl carbon atom. This can be understood in terms of changes in bond formation (C-N) and bond breaking (C-O) in the transition state with charges in electron-attracting ability of the substituents. The predicted substituent effects may indicate a small increase in bond formation and thus a tighter transition state, in benzyl p-bromobenzene sulfonate than in benzyl p-nitrobenzenesulfonate. Predicting made by Thornton concerning the substituent effects on SN2 transition state structures agrees with the changes in bond formation and bond breaking.

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Quantitative Analysis of ″Polymer-Balls″ in Aqueous Solutions by Small-Angle Neutron Scattering

  • Shibayama, Mitsuhiro;Okabe, Satoshi;Nagao, Michihiro;Sugihara, Shinji;Aoshima, Sadahito;Harada, Tamotsu;Matsuoka, Hideki
    • Macromolecular Research
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    • v.10 no.6
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    • pp.311-317
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    • 2002
  • The quantitative analysis of polymer micelles consisting of amphiphilic block copolymers was carried out by small-angle neutron scattering (SANS). The block copolymers, made of poly(2-ethoxyethyl vinyl ether-b-2-hydroxyethyl vinyl ether)(poly(EOVE-b-HOVE)), exhibited a sharp morphological transition from a homogeneous solution to a micelle structure with increasing temperature. This transition is accompanied by a formation of spherical domains of poly(EOVE) with a radius around 200 \AA. The variations of the size and its distribution of the domains were investigated as a function of polymer concentration and temperature. The validity of SANS analysis, including the wavelength- and incident-beam-smearing effects of the SANS instrument, was examined with a pre-calibrated polystyrene latex.

Finding State Transition Functions of One-Dimensional Cellular Automata by Evolutionary Algorithms (일차원 셀룰러 오토마타 상에서 진화 알고리즘을 이용한 상태전이함수 찾기)

  • Park, Jongwoo;Wang, Sehee;Wee, Kyubum
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.5
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    • pp.187-192
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    • 2019
  • Majority problem and synchronization problem on cellular automata(CA) are hard to solve, since they are global problems while CA operate on local information. This paper proposes a way to find state transition rules of these problems. The rules of CA are represented as CMR(conditionally matching rules) and evolutionary algorithms are applied to find rules. We find many solution rules to these problems, compared the results with the previous studies, and demonstrated the effectiveness of CMR on one-dimensional cellular automata.

Effect of competition between superconductivity and ferromagnetism in GdBa2Cu3O7-x/La0.7Sr0.3MnO3 bilayers

  • Oh, Jun-Yung;Yang, Dong-Seok;Kang, Byeongwon
    • Progress in Superconductivity and Cryogenics
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    • v.24 no.2
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    • pp.19-22
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    • 2022
  • We studied the effect of substrate-induced strain state on the superconducting transition in GdBa2Cu3O7-x(GdBCO)/La0.7Sr0.3MnO3 (LSMO) bilayers deposited on a LaAlO3 (LAO) substrate. The stain state of LSMO is controlled by increasing the thickness from 20 nm to 80 nm. Analyses on the extended X-ray absorption fine structure (EXAFS) measurements reveal difference in the direction of MnO6 octahedral distortion depending on the LSMO thickness, which leads to a difference in anisotropy of magnetization of LSMO layer. The superconducting transitions of our system are strongly correlated with the magnetic anisotropy accompanied by the MnO6 octahedron distortion in a specific direction. This result suggests the possibility of improving the superconducting transition in the GdBCO/LSMO bilayer system by controlling the degree of competition between superconductivity and ferromagnetism via adjusting strain state in the LSMO layer.

Magnetic Properties of Carbon Chains Doped with 4d Transition Metals

  • Jang, Y.R.;Lee, J.I.
    • Journal of Magnetics
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    • v.13 no.1
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    • pp.7-10
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    • 2008
  • The structural and magnetic properties of functionalized carbon chains doped with 4d transition metals, such as Ru, Rh, and Pd, were investigated using the full-potential linearized augmented plane wave (FLAPW) method. The carbon nanowire doped with Ru exhibited a ferromagnetic ground state with a sizable magnetic moment, while those doped with Rh and Pd had nonmagnetic ground states. For the Ru-doped chain, the density of states at the Fermi level showed large spin polarization, which suggests that the doped nanowire could be used for spintronic applications.

SN2 Transition State Variation in the Benzenesulfonyl Chloride Sovolysis

  • Lee, Ik-Choon;Koo, In-Sun;Kang, Han-Keun
    • Bulletin of the Korean Chemical Society
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    • v.2 no.2
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    • pp.41-45
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    • 1981
  • For solvolyses of benzenesulfonylchlorides we determined transfer enthalpies of transition states, and solvent (TFE + EtOH) and substituent effects on rates. We have used the More O'Ferrall plots to show that transition states variation caused by solvent and substituent changes is consistent with an associative SN2 mechanism for the nucleophilic substitution reaction of benzenesulfonylchlorides.

The Effect of External Noise on Dynamic Behaviors of the Schlogl Model with the Second Order Transition for a Photochemical Reaction

  • 김경란;Lee, Dong J.;신국조
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1119-1121
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    • 1995
  • The method for the Schlo"gl model with the first order transition is extended to the Scho;gl model with the second order transition for a photochemical reaction. We obtain the explicit results of the time-dependent average and the time correlation function at the unstable steady state of the model in the neighborhood of the Gaussian white noise and then discuss the effect of noise on the dynamic properties.