• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.443-453
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• 2013

The hybrid test is one of the most advanced test methods to predict the structural dynamic behavior with the interaction between a physical substructure and a numerical modeling in the hybrid control system. The purpose of this study is to perform the multi-directional dynamic test of a steel frame structure with the real-time hybrid system and to evaluate the validation of the results. In this study, FEAPH, nonlinear finite element analysis program for hybrid only, was developed and the hybrid control system was optimized. The inefficient computational time was improved with a fixed number iteration method and parallel computational techniques used in FEAPH. Furthermore, the previously used data communication method and the interface between a substructure and an analysis program were simplified in the control system. As the results, the total processing time in real-time hybrid test was shortened up to 10 times of actual measured seismic period. In order to verify the accuracy and validation of the hybrid system, the linear and nonlinear dynamic tests with a steel framed structure were carried out so that the trend of displacement responses was almost in accord with the numerical results. However, the maximum displacement responses had somewhat differences due to the analysis errors in material nonlinearities and the occurrence of permanent displacements. Therefore, if the proper material model and numerical algorithms are developed, the real-time hybrid system could be used to evaluate the structural dynamic behavior and would be an effective testing method as a substitute for a shaking table test.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.219-225
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• 2018

The objectives of this study is to analyze the impact of open information innovation which consisted of external technology acquisition and external technology exploitation on export performance by integrating with strategic alliance factors. This study empirically analyzed six hypotheses in 201 sample using the PLS (Partial Least Square) of the structural equation model to verify the moderating effects of organizational culture on the relationship among open information innovation, strategic alliance and export performance. As a result, external technology acquisition dose not affect strategic alliances. On the other hand, external technology exploitation has a positive impact on strategic alliances. Strategic alliances also have a positive impact on export performance. As a result of the moderating effect analysis, the interaction between organizational culture and external technology acquisition has positively influenced strategic alliances. In addition, the moderating effect of organizational culture and external technology exploitation has a significant effect on strategic alliances. However, moderating effect of organizational culture and strategic alliance dose not affect export performance. This study has a contribution to the analysis of the moderating effects of organizational culture. In the future, integrated analysis of open information innovation and external factors is needed.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.31-42
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• 2013

This research sheds light on the non-intrusive traits of mobile devices (Electronic Guidebook, Rememberer, I-Guides and eXspot) deployed in Exploratorium for enhancing visitor experience via case studies. In an interactive exhibition environment, non-intrusiveness was the key to supporting the immersive experience and meaning-making for visitors. The usability of hand-held devices directly impacted on the non-intrusiveness, thereby reshaping the form-factors of mobile devices. The change in from-factor has also minimized the functions of devices as the remember of museum experience. Furthermore, the role of mobile devices, which turned from a supposed multi-media guide to a mere rememberer, made them virtually impossible for realizing the "seamless visiting model" originally planned. An array of projects carried out in Exploration have achieved some degree of success such as increasing viewing time as well as reinforcing post-visit activities. However, taken from musicological perspective, increase in viewing time is by all means insufficient to be taken as proof since it is assumed to be achieved by photo-taking (i.e. MyExploratorium) rather than by interacting between visitors and exhibits. This issue --increased viewing time -- needs to be analyzed in depth. All in all, mobile devices used in Exploratorium can be defined as a learning tool/educational supporting medium based on personalization for (visitors') optimizing extended museum experience.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.175-182
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• 2013

The purpose of this study was to investigate the factors that influence elementary school learners' participation in cyber home study, and to suggest possible solutions to problem of the participation rates. To identify the factors, we analyzed the literature and developed a questionnaire consisting of 8 possible factors and 33 items. Data gathered from 429 elementary school learners were analyzed in a logistic regression model, which was utilized to determine the probability of the learner's participation in cyber home study because of any of the identified variables. We studied the following variables: problem from learning motivation & attitude, burden from computer, difficulty of new learning method, problem from instructional design, difficulty of interaction, problem from screen design, and problem from learning environment. The results indicated that two factors were important: burden from computer, difficulty of new learning method. That is to say, having a low level of burden of computer and difficulty of new learning method helps improve the rate of elementary school learners' participation in cyber home study.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.139-148
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• 2015

By increasing the vertical stiffness of the rail fastening system, the dynamic wheel load of the vehicle can be increased on the ballast track, though this increases the cost of track maintenance. On the other hand, the resistance acting on the wheel is decreased, which lowers the cost of the electric power to run the train. For this reason, the determination of the optimal fastener stiffness is important when attempting to minimize the economic costs associated with both track maintenance and energy to operate the train. In this study, a numerical method for evaluating the optimal vertical stiffness of the fasteners used on ballast track is presented on the basis of the process proposed by L$\acute{o}$pez-Pita et al. They used an approximation formula while calculating the dynamic wheel load. The evaluated fastener stiffness is mainly affected by the calculated dynamic wheel load. In this study, the dynamic wheel load is more precisely evaluated with an advanced vehicle-track interaction model. An appropriate range of the stiffness of the fastener applicable to the design of ballast track along domestic high-speed lines is proposed.

• Journal of Service Research and Studies
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• v.8 no.2
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• pp.67-76
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• 2018

Service quality research has been the subject of service studies for many years. This study is an exploratory study to improve the service quality measurement factor, and the research has been carried out reflecting the nature of the service; relationship quality, interactivity, horizontality, and harmony. Also, among the developed service quality measurement factors, the research model is reconstructed considering the major factors such as environmental quality, result quality, and convenience quality. Relationality and interactivity redesigned the quality factor, which is called interactive quality. The redesigned service quality factors consisted of interaction quality, result quality, environmental quality, convenience quality, harmonious quality, and horizontal quality. Experimental group evaluation was conducted on the quality factors and 18 measurement items were derived. A questionnaire was conducted to verify the validity of the 18 items. As a result of the questionnaire analysis, 6 factors and 15 items among the 18 items of service quality measurement factor were found valid. The six factors for the service quality measurement presented in this study are the results of the early stage research, but they can be used to improve the service quality factor in the future. However, this is significant because it reflects the characteristics of services that are consistent with the service economy. In particular, the horizontal quality and harmony quality factors are new factors not mentioned in the previous studies and need to be verified through further detailed studies. Further research is needed to improve the service quality measurement factors reflecting the nature of services and the characteristics of new services.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.43-53
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• 2020

The purpose of this study is to reduce the anxiety factors of fires by following evacuation tips in case of fire in an apartment household. This study analyzed the moderating effects of the control offices' competence in control on safety awareness and fire response. The study results were as follows. First, the residents and control staff's safety awareness had a positive effect on the fire response performance. This indicates that the higher the residents and control staff's safety awareness level, the higher the fire responsive performance. Second, the higher the control offices' control competence level, the better the apartment residents and control staff's safety awareness had a positive effect on the fire response performance. These results indicate that the higher the control office heads' leadership, the higher the apartment residents' housing satisfaction and that the more communicative the control office heads' attitude toward the residents, the better their attitude had a positive effect on the fire response performance. Lastly, the control offices' control competence was analyzed to have a moderating effects on the effect of the apartment residents and control staff's safety awareness level on the fire response performance. These results showed that the change in the model's R² value showed an increasing trend in stages as the value increased more in the stage 2 than the stage 1 and even more in the stage 3 with the interaction terms of the moderating variables added. For this reason, the control offices' control competence which was a moderating variable was analyzed to have a moderating effect on the effect of residents and control staff's safety awareness level on the fire response performance.

• Management & Information Systems Review
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• v.35 no.1
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• pp.253-271
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• 2016

This study is to investigate the impact of the social capital on organization trust, and the impact of the organization trust on recommendation intention, and turnover intention. And by this it is also to integrally analyze through what route social capital affects the recommendation intention and turnover intention. An actual analysis through covariance structural equation model was made targeting the members of small and medium sized manufacturing companies. The results of the actual analysis showed that the relational dimension in the social capital had an positive(+) and the most pervasive effect on the organization trust. Relational dimension refers to the formation relationships among members and has a significant value in the interaction in the relation between subordinates and superiors, between colleagues, and between departments. Secondly, the cognitive dimension in the social capital was revealed to have no significant effect on the organization trust and structural dimension was revealed to have a positive(+) effect on the organization trust. Structural dimension refers to the capital value which shows itself in the social network and relationship existing between the members and is formed through building the best network within an organization. Thirdly, organization trust was revealed to have a positive(+) impact on the recommendation intention and to have a negative(-) impact on the turnover intention. Finally, the summary, implications, limitations, and future research direction of this study were presented.

• Journal of the Korean Chemical Society
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• v.18 no.4
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• pp.223-238
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• 1974

CNDO/2 MO theoretical studies and kinetic studies of halide exchange reactions for alkylchloroformates have been carried out in order to investigate structure-reactivity relationship of alkylchloroformates. From the result of energetics, it was concluded that the most stable configuration of alkylchloroformate is that in which alkyl group and chlorine are trans to each other, and that the hindered rotation about the bond between the carbonyl carbon and alkoxy-oxygen bond is attributed to the ${\pi}-$electron delocalization. It has been found that the large charge separation is due to -M effect of carbonyl and alkoxy oxygens and-I effect of chlorine. The order of rates in solvents studied was $(CH_3)_2 > CO > CH_3CN{\gg}MeOH.$$I^->Br^->Cl^-$ in protic solvent, and of Cl^->Br^- >I^-$ in dipolar aprotic solvents. Alkyl group contribution has the decreasing order of $CH_3-> C_2H-{\gg}i-C_3H_7-.$ The solvent effect has been interpreted on the basis of initial and final state contribution. A transition state model has been suggested, and it has been proposed that the most favorable mechanism is the addition-elimination. From the results of activation parameters and electronic properties, an energy profile has been proposed. Structural factors determining reactivities of alkylchloroformates have been shown to be charge, energy level of ${\alpha}^*LUMO$ to C-Cl bond and ${\alpha}^{\ast} $antibonding strength with respect to C-Cl bond in this MO. Charge and polarizability of nucleophile, and the interaction of these effects with solvent structures are also found to be important.

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.39-52
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• 2012

Surface-subsurface interactions are an intrinsic component of the hydrologic response within a watershed. In general, these interactions are considered to be one of the most difficult areas of the discipline, particularly for the modeler who intends simulate the dynamic relations between these two major domains of the hydrological cycle. In essence, one major complexity is the spatial and temporal variations in the dynamically interacting system behavior. The proper simulation of these variations requires the need for providing an appropriate coupling mechanism between the surface and subsurface components of the system. In this study, an approach for modelling surface-subsurface flow and transport in a fully intergrated way is presented. The model uses the 2-dimensional diffusion wave equation for sheet surface water flow, and the Boussinesq equation with the Darcy's law and Dupuit-Forchheimer's assumption for variably saturated subsurface water flow. The coupled system of equations governing surface and subsurface flows is discretized using the finite volume method with central differencing in space and the Crank-Nicolson method in time. The interactions between surface and subsurface flows are considered mass balance based on the continuity conditions of pressure head and exchange flux. The major module consists of four sub-module (SUBFA, SFA, IA and NS module) is developed.