• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.93-103
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• 2002

Reinforced earth structure has been regarded as general structure in order to achieve efficient land utilization as well as securing safety in railway service lines in other countries, but there are no construction actual results in Korea. In this study, the soil-geogrid interaction mechanism was investigated experimentally and numerical analysis was performed to predict Pull-out behaviour of geogrid embedded in reinforced earth body. This experimental data and analysis result can not contribute to understand the soil-geogrid interaction mechanism at soil-geogrid interface but also be used in design practice of the railway reinforced earth structures.

• Journal of Photoscience
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• v.12 no.1
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• pp.11-15
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• 2005

The mechanism of interaction of two drugs viz., amoxicillin and cloxacillin with bovine serum albumin has been investigated using fluorescence absorption and circular dichroism spectroscopy. The quenching mechanism of fluorescence of bovine serum albumin by amoxicillin and cloxacillin was discussed. The binding sites number n and apparent binding constant Kwere measured by fluorescence quenching method. The thermodynamic parameters obtained from data at different temperatures were calculated. The distance r between donor (bovine serum albumin) and acceptor (amoxicillin and cloxacillin) was obtained according to Forster theory of non-radiative energy transfer. The effect of common ions on binding constant was also investigated. The results of synchronous fluorescence spectra, UV-vis absorption spectra and circular dichroism of BSA in presence of amoxicillin and cloxacillin show that the conformation of bovine serum albumin changed

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.985-990
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• 1994

Cross-interaction constants, ${\rho}^e_{XY}$, ${\rho}_{YZ}$ and ${\rho}_{XZ}$ are defined using observed rate constant, k_N=(k_1/k_{-1})k_2=Kk_2$, for the stepwise carbonyl addition reactions involving the rate-limiting breakdown of a tetrahedral intermediate $(T^{\pm})$. Abundant experimental evidence in the literature enables us to determine signs for the three constants for such mechanism, ${\rho}^e_{XY}$>0, ${\rho}_{YZ}$<0 and ${\rho}_{XZ}$0. These are in contrast to those for the concerted $S_N2$ mechanism, ${\rho}_{XY}$<0, ${\rho}_{YZ}$>0 and ${\rho}_{XZ}$, and provide useful mechanistic criteria. In the light of these criteria, mechanisms of some nucleophilic reactions of carbonyl compounds are re-examined.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1179-1182
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• 1997

The rates for the reaction of (Z)-phenacyl (X)-benzenesulfonates with (Y)-pyridines in acetone were measured by an electrical conductivity method at 1-2000 bars and 45 ℃. The magnitudes of the Hammett reaction constants, ρX, ρY and ρZ, represent the degree of Nu-C bond formation and that of C-L bond breaking. The magnitude of correlation interaction term ρij can be used to determine the structure of the transition state (TS) for the SN reaction. As the pressure is increased, the Hammett reaction constants, ρX, |ρY| and ρZ are increased, but correlation interaction coefficient, |ρXZ| and ρYZ, are decreased. The results indicate that the reaction of (Z)-phenacyl (X)-benzenesulfonates with (Y)-pyridines probably moves from an associative SN2 to late-type SN2 mechanism by increasing pressure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2286-2309
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• 2016

Overlay networks have been widely deployed upon the Internet by Service Providers (SPs) to provide improved network services. However, the interaction between each overlay and traffic engineering (TE) as well as the interaction among co-existing overlays may occur. In this paper, we adopt both non-cooperative and cooperative game theory to analyze these interactions, which are collectively called hybrid interaction. Firstly, we model a situation of the hybrid interaction as an n+1-player non-cooperative game, in which overlays and TE are of equal status, and prove the existence of Nash equilibrium (NE) for this game. Secondly, we model another situation of the hybrid interaction as a 1-leader-n-follower Stackelberg-Nash game, in which TE is the leader and co-existing overlays are followers, and prove that the cost at Stackelberg-Nash equilibrium (SNE) is at least as good as that at NE for TE. Thirdly, we propose a cooperative coalition mechanism based on Shapley value to overcome the inherent inefficiency of NE and SNE, in which players can improve their performance and form stable coalitions. Finally, we apply distinct genetic algorithms (GA) to calculate the values for NE, SNE and the assigned cost for each player in each coalition, respectively. Analytical results are confirmed by the simulation on complex network topologies.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1041-1045
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• 2004

Kinetic studies of the pyridinolysis $(XC_5H_4N)$ of aryl dithiomethylacetates $(CH_3CH_2C(=S)SC_6H_4Z,\;1)$ are carried out in acetonitrile at $60.0^{\circ}C$. A biphasic Bronsted plot is obtained with a change in slope from a large $({\beta}X\;{\cong}\;0.8)$ to a small $({\beta}X\;{\cong}\;0.2)$ value at $pK_a^{\circ}$ = 5.2, which is attributed to a change in the rate limiting step from breakdown to formation of a zwitterionic tetrahedral intermediate, $T^{\pm}$, in reaction path as the basicity of the pyridine nucleophile increases. This mechanism is supported by the change of the cross-interaction constant ${\rho}xz$ from a large positive ( ${\rho}xz$ = +1.36) for the weakly basic pyridines to a small negative ( ${\rho}_xz$ = -0.22) value for the strongly basic pyridines. The magnitudes of ${\rho}z$ and activation parameters are also consistent with the proposed mechanism.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1135-1140
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• 2003

The kinetics and mechanism of the pyridinolysis $(XC_5H_4N)$ of Y-aryl phenyl isothiocyanophosphates (1;$(YC_6H_4O)\;(C_6H_5O)$P(=O)NCS) are investigated in acetonitrile at 55.0 ℃. The Hammett plots for substituent (Y) variations in the substrate (log k₂ vs σY) exhibit a convex upward biphasic type with breaks at Y = H. For electron-donating Y groups the Hammett coefficients, ρY, are positive and cross-interaction constant ρXY is negative, while those for electron-withdrawing Y groups ρY values are negative with a positive ρXY. These results are interpreted to indicate mechanistic change at the breakpoint (σY = 0) from a concerted to a stepwise mechanism with rate-limiting expulsion of the $^-NCS$ group from a trigonal bipyramidal pentacoordinated (TBP-5C) intermediate. Biphasic plots of log k₂ vs σX or $pK_a$(X) with steeper slopes for the more basic nucleophiles are obtained suggesting an equatorial nucleophilic attack in contrast to an apical attack for the less basic nucleophiles with smaller magnitude of ρX or βx.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.197-202
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• 2004

In order to design accurately sand compaction pile (SCP) method with low replacement area ratio, it is important to understand the mechanical interaction between sand piles and clays and its mechanism during consolidation process of the composition ground. In this paper, a series of numerical analyses on composition ground improved by SCP with low replacement area ratio were carried out, in order to investigate the mechanical interaction between sand piles and clays. The applicability of numerical analyses, in which an elasto-viscoplastic consolidation finite element method was applied, could be confirmed comparing with results of a series of model tests on consolidation behaviors of composition ground improved by SCP. And, through the results of the numerical analyses, each mechanical behaviors of sand piles and clays in the composition ground during consolidation was elucidated, together with stress sharing mechanism between sand piles and clays.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.162-169
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• 2003

Excavation by TBM can be characterized by a rock-machine interaction during the cutting process on a small scale, but on a large scale the interaction between the rock mass and TBM becomes very significant. For the planning and evaluation of TBM tunnelling it needs to understand rock fracture mechanism by a cutter or cutters on a small scale, and to estimate penetration rate, advance rate and utilization on a large scale. In this study rock chipping mechanism due to cutter-penetration is analysed by numerical simulation, showing that rock chipping is mainly occurred by tensile failure. Also, through the analysis of factors that affect on TBM procedures in various assessment systems, it is determined that the key elements that should be considered in the planning and evaluation of TBM tunnelling are classified into rock properties, the geological structures and properties of rock mass, and the structural and functional specifications of the machine. The user-friendly assessment tool is developed, so that penetration rate, advance rate and TBM utilization are evaluated from various input data. The tool developed in this study can be applied to a practical TBM tunnelling by understanding TBM tunnelling procedures.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.73-86
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• 1994

In addition to classic cholinergic and adrenergic pathways, the existence of a third division of autonomic control in the human airways has been proved. It is called a nonadrenergic noncholinergic(NANC) nervous system, and difficult to study in the absence of specific blockers. Neuropeptides are certainly suggested to be transmitters of this NANC nervous system. It is very frustrating to understand the pathophysiologic role of these peptides in the absence of any specific antagonists. However, further studies of neuropeptides might eventually lead to novel forms of treatment for bronchial asthma. Another study of the interaction between different components of the autonomic nervous system, either in ganglionic neurotransmission or by presynaptic modulation of neurotransmitters at the end-organ will elute neural control in airway disease, particularly in asthma. Studies of how autonomic control may be disordered in airway disease should lead to improvements in clinical management. Epithelial damage due to airway inflammation in asthma may induce bronchial hyperresponsiveness. Axon reflex mechanism is one of possible mechanisms in bronchial hyperresponsiveness. Epithelial damage may expose sensory nerve terminals and C-fiber nrve endings are stimulated by inflammatory mediators. Bi-directional communication between the nerves and mast cells may have important roles in allergic process. The psychological factors and conditioning of allergic reactions is suggested that mast cell activation might be partly regulated by the central nervous system via the peripheral nerves. Studies in animal models, in huamn airways in vitro and in patients with airway disease will uncover the interaction between allergic disease processes and psychologic factors or neural mechainsms.