• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4117-4121
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• 2012

The solvolysis rate constants of allyl chloroformate ($CH_2=CHCH_2OCOCl$, 3) in 30 different solvents are well correlated with the extended Grunwald-Winstein equation, using the $N_T$ solvent nucleophilicity scale and $Y_{Cl}$ solvent ionizing scale, with the sensitivity values of $0.93{\pm}0.05$ and $0.41{\pm}0.02$ for l and m, respectively. These l and m values can be considered to support a $S_N2$ reaction pathway. The activation enthalpies (${\Delta}H^{\neq}$) were 12.5 to 13.4 $kcal{\cdot}mol^{-1}$ and the activation entropies (${\Delta}S^{\neq}$) were -34.4 to -37.3 $cal{\cdot}mol^{-1}{\cdot}K^{-1}$, which is also consistent with the proposed bimolecular reaction mechanism. The solvent kinetic isotope effect (SKIE, $k_{MeOH}/k_{MeOD}$) of 2.16 was also in accord with the $S_N2$ mechanism. The values of product selectivity (S) for the solvolyses of 3 in alcohol/water mixtures was 1.3 to 3.9, which is also consistent with the proposed bimolecular reaction mechanism.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.1
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• pp.1-9
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• 2021

Most commercial buildings among existing RC buildings in Korea have a multi-story wall-frame structure where RC shear wall is commonly used as its core at stairways or elevators. The members of the existing middle and low-rise wall-frame buildings are likely arranged in ordinary details considering building occupancy, and the importance and difficulty of member design. This is because there are few limitations, considerations, and financial burdens on the code for designing members with ordinary details. Compared with the intermediate or unique details, the ductility and overstrength are insufficient. Furthermore, the behavior of the member can be shear-dominated. Since shear failure in vertical members can cause a collapse of the entire structure, nonlinear characteristics such as shear strength and stiffness deterioration should be adequately reflected in the analysis model. With this background, an 8-story RC wall-frame building was designed as a building frame system with ordinary shear walls, and the effect of reflecting the shear failure mode of columns and walls on the collapse mechanism was investigated. As a result, the shear failure mode effect on the collapse mechanism was evident in walls, not columns. Consequently, it is recommended that the shear behavior characteristics of walls are explicitly considered in the analysis of wall-frame buildings with ordinary details.

• Structural Engineering and Mechanics
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• v.82 no.3
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• pp.343-354
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• 2022

An understanding of the mechanism of concrete girders repaired with CFRP plates and its influence on the dynamic parameters is presented in this paper. Dynamic parameters are governed by the relationship with the physical properties of concrete girders and CFRP plates as well as the adhesive layer between them. A brief explanation of the mechanism of the composite action of concrete girders repaired with CFRP is also given in this paper. Experimental work was carried out to validate the theory of the composite action. The results show a decrease in the modal parameters of CFRP repaired girders that were turned over during the repair procedure, which contrasts with the proven static-based results that CFRP plates increase the stiffness of repaired girders. The composite action theory has explained the results based on the tension and compression forces' growth at the adhesive layer between the CFRP plates and girder surface during the repair procedure. Other girders were prepared and repaired without turning over in order to avoid tension and compression forces at the adhesive layer. The experimental results show an increase in the dynamic parameters of CFRP repaired girders that were not turned over during the repair procedure, which aligns with the static-based results. The study concludes that the dynamic parameters are excellent indicators for the assessment of CFRP repaired concrete girders. The study also suggests that researchers should not turn over damaged concrete girders to repair them with CFRP plates if they intend to study the dynamic parameters, in order to avoid the proposed composite action effect on modal parameters.

• Journal of Distribution Science
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• v.14 no.6
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• pp.81-87
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• 2016

Purpose - In recent, a research finds that advanced selling can influence a consumer's choice(Kim et al., 2013). Advanced selling is defined as the new product launching strategy which company allows consumers to preorder new product before its release(Chu & Zhang, 2011). Prior researches have focused on the benefits of advanced selling(e.g., information gathering for demand prediction, an advantage for pricing strategy, and so on) for companies using this strategy(Chen, 2001; Chu & Zhang, 2011; Li & Zhang, 2013; Tang et al., 2004; Xie & Shugan, 2009). However, Kim et al.(2013) find it can also influence a consumer's choice. In detail, they suggest that when consumers use advanced selling, they are likely to prefer high-performance options rather than low-price options based on construal level theory(Trope & Liberman, 2003). In this paper, we tried to expand the prior researches for finding the mechanism of the influence of advanced selling on a consumer's choice. The purpose of this research is to test the mediating effect on the influence of advanced selling. Research design, data, and methodology - To find the mechanism of the influence of advanced selling, we designed an experiment for testing mediation effect. we recruited 93 students from a university. We assigned participants into one of two groups using randomization method. The participants with each group were given a scenario describing the sales strategy. Finally, they made a choice between high-performance option and low-price option. Sequentially, they also responded some questions for testing mediation effect. Results - First, we replicated prior research to test the influence of advanced selling. As a result, we could find that consumers prefer the high-performance option when they preorder it to purchase at the time of consumption. Thus, the replication result is the same as prior research. Second, we tested that advanced selling can influence the perception of temporal distance. The results confirmed that consumers perceived longer temporal distance in advanced selling condition(β = 1.575, SE = 0.272, p < 0.001). Third, we predicted that temporal distance can increase the importance of desirable attributes and decrease the importance of feasible attributes. The results suggested that temporal distance decreased significantly the importance of attributes related to feasibility(β = -0.19, SE = 0.07, p < 0.01), however, it had non-significant effect on increasing the importance of desirable attributes. Finally, we used Sobel-test for testing mediation effect, and it confirmed that the importance of feasible attributes had mediating role of the influence of advanced selling(Sobel test statistic = -2.110, SE = 0.111, p < 0.05). Conclusions - In this paper, we tried to find the mechanism of the influence on advanced selling from a consumer's choice. With an experiment, we confirmed that the importance of feasible attributes could mediate the effect on advanced selling. Therefore, we suggested some theoretical and practical contributions from this research. Finally, we discussed research limitations and suggested future research topics.

• Journal of Industrial Convergence
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• v.21 no.3
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• pp.57-64
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• 2023

As the technology advances and convergence progresses, companies are increasingly interested in the appropriability mechanism. Therefore in this study tried to understand the effectiveness of the appropriability mechanism of domestic IT companies. To this end, 7 appropriability mechanisms were finally derived and empirically analyzed from a review of previous studies and experts. As a result of the analysis, the importance of lead time advantage, patent, secrecy, complementary sales and service, design registered, complementary manufacturing, and learning curve effect was shown in the order of SW companies. HW companies, the importance of patent, secrecy, lead time advantage, design registered, complementary sales and service, learning curve effect, and complementary manufacturing were shown in the order of importance. Also patent, secrecy, and lead time advantage was selected as important factors. The results of in this study are expected to be used as useful guidelines on establishing an appropriability mechanism strategy in companies.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.2
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• pp.243-250
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• 2003

The extinction behavior and the unsteady response of augmented reduced mechanism(ARM) have been investigated by adopting an OPPDIF code and a numerical solver for the flamelet equations. By comparing the performance of the ARM based on Miller and Bowman's mechanism(MB-ARM) with that of the ARM based on GRI-Mech 3.0(GRI-3.0-ARM), it is identified that the MB-ARM is more suitable for the unsteady calculation because it is relatively less stiff than GRI-3.0-ARM during an ignition process. The steady results using the MB-ARM, which is modified to predict reasonably the extinction point of experiment, are in excellent agreement with those from full mechanism. Under the sinusoidal transient disturbances of scalar dissipation rate, the unsteady responses of the flame temperature and species concentrations using a modified MB-ARM show in very close agreement with those from full mechanism. It is presumed that above modified MB-ARM is very suitable for the unsteady simulation of turbulent flames because it gives not only a low computational cost but also a good prediction performance for flame structure, extinction point and unsteady response.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.650-656
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• 1995

Rate Constants of hydrolysis of N-(benzenesulfonyl)-C-(N-methylanilino)imidoyl chlorides were determined by UV spectrophotometry in 50% (v/v) aqueous methanol at 25$^{\circ}C.$ On the basis of rate equation, substituent effect, solvent effect, salt effect, thermodynamic parameters and hydrolysis product analysis, it may be concluded that the hydrolysis of N-(benzenesulfonyl)-C-(N-methylanilino)imidoyl chlorides proceed through $S_N1$ mechanism via azocarbonium ion intermediate below pH 9.0, while aebove pH 10.0 the hydrolysis proceeds through nucleophilic addition-elimination ($Ad_{N-E}$) mechanism.

• Korean Journal of Materials Research
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• v.19 no.11
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• pp.625-630
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• 2009

Embedding of active devices in a printed circuit board has increasingly been adopted as a future electronic technology due to its promotion of high density, high speed and high performance. One responsible technology is to embedded active device into a dielectric substrate with a build-up process, for example a chipin-substrate (CiS) structure. In this study, desmear treatment was performed before Cu metallization on an FR-4 surface in order to improve interfacial adhesion between electroless-plated Cu and FR-4 substrate in Cu via structures in CiS systems. Surface analyses using atomic force microscopy and x-ray photoemission spectroscopy were systematically performed to understand the fundamental adhesion mechanism; results were correlated with peel strength measured by a 90o peel test. Interfacial bonding mechanism between electrolessplated Cu and FR-4 substrate seems to be dominated by a chemical bonding effect resulting from the selective activation of chemical bonding between carbon and oxygen through a rearrangement of C-C bonding rather than from a mechanical interlocking effect. In fact, desmear wet treatment could result in extensive degradation of FR-4 cohesive strength when compared to dry surface-treated Cu/FR-4 structures.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.53-64
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• 2007

Gravure printing is the most useful printing process than any other engraving printing method. According to the cell which is variable size and depth, ink is transferred substrates. So, the amount of ink from cells has a great effect on the qualities of final printed products. The variables effect on the printability of final products are proportion of the width and length, the rhelogical properties, roll speed etc. However the mechanism of gravure is difficult to study scientifically because of high speed and excessively small size of the cell. To approach the mechanism we experimented the real test by using gravure printability. The condition of variables of IGT is pressure and velocity. By using Polyflow 3. 10. 0 simulation software, we built up the theoretical model under the constant variables. Then, we compared the real test with the simulation results. Therefore, it is studied the mechanism of gravure scientifically and it can be analysed the effect of the variable conditions.

• Journal of IKEEE
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• v.22 no.2
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• pp.499-505
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• 2018

Since feedback field-effect transistors (FBFETs) have ideal switching characteristics resulting from feedback phenomenon caused by electrons and holes in the channel region, the researches about FBFET devices have been proposed and demonstrated worldwide recently. The device operated with novel principle can operate as a switching electronic device. Besides, because the hysteresis characteristics of the device by accumulated electrons and holes in channel region can be also utilized for memory applications, its application range is wide. In this paper, we cover various device structures of FBFET proposed until now and their operation mechanism, and then look into their applicable fields.