• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.1001-1012
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• 2018

Regarding the small- and medium-sized enterprises in Korea that manufacture the railway vehicle parts, there are over 250 related companies. And they have been surviving in the form of producing and delivering the parts of the railway vehicles by importing the technologies and the products of the foreign countries rather than possessing their own technological abilities. Due to this, regarding the industry of the core components of the railroads, the dependence on the overseas has been high. As such, although, for supporting the small- and medium-sized enterprises that manufacture the railway vehicle parts, the government has been strengthening the diverse policy supports, it is a fact that the effectiveness of the support is not high. And, in order to effectively support these, there is a need to understand clearly and definitely what the important promotion factors are in the process of the technology commercialization. Accordingly, through the precedent researches regarding the factors that promote the technology commercializations of the small- and medium-sized enterprises that manufacture the railway vehicle parts, this research had extracted 10 main items. And the level of the importance of these indices was analyzed by using the AHP (Analytic Hierarchy Process). As a result of the AHP analysis, the factors within a corporation appeared to be the most important factor. And, as for the lower-ranking item, the commercialization capability was analyzed to be the most important item. It is highly expected that the contents and the results of this research will be usefully used when formulating the planning of the support program and the support policy for the technology commercializations by the public research organizations and the railroad management organization, which is an organization that supports the small- and medium-sized enterprises that manufacture the railway vehicle parts.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.347-362
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• 2019

Underground excavation using TBM machines has been increasing to reduce complaints caused by noise, vibration, and traffic congestion resulted from the urban underground construction in Korea. However, TBM excavation design and construction still need improvement because those are based on standards of the technologically advanced countries (e.g., Japan, Germany) that do not consider geological environment in Korea at all. Above all, although TBM performance is a main factor determining the TBM machine type, duration and cost of the construction, it is estimated by only using UCS (uniaxial compressive strength) as the ground parameters and it often does not match the actual field conditions. This study was carried out as part of efforts to predict penetration rate suitable for Korean ground conditions. The effective parameters were defined through the correlation analysis between the penetration rate and the geotechnical parameters or TBM performance parameters. The effective parameters were then used as variables of the multiple regression analysis to derive a regression model for predicting TBM penetration rate. As a result, the regression model was estimated by UCS and joint spacing and showed a good agreement with field penetration rate measured during TBM excavation. However, when this model was applied to another site in Korea, the prediction accuracy was slightly reduced. Therefore, in order to overcome the limitation of the regression model, further studies are required to obtain a generalized prediction model which is not restricted by the field conditions.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1193-1201
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• 2020

This study aims to develop a regression model that estimates a low-flow index that can be applied to ungauged basins. A total of 30 midsized basins in South Korea use long-term runoff data provided by the National Integrated Water Management System (NIWMS) to calculate average low-flow, average minimum streamflow, and low-flow index duration and frequency. This information is used in the correlation analysis with 18 basin factors and 3 climate change factors to identify the basin area, average basin altitude, average basin slope, water system density, runoff curve number, annual evapotranspiration, and annual precipitation in the low-flow index regression model. This study evaluates the model's accuracy by using the root-mean-square error (RMSE) and the mean absolute error (MAE) for 10 ungauged, verified basins and compares them with the previous model's low-flow calculations to determine the effectiveness of the newly developed model. Comparative analysis indicates that the new regression model produces average low-flow, attributed to the consideration of varied basin and hydrologic factors during the new model's development.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.687-695
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• 2021

With the recent occurrence of large-scale earthquakes in Korea, the importance of seismic design has greatly increased. Seismic design standards stipulate that dynamic time history analysis be performed for important or special structures. In the seismic analysis and design of such structures, determining a rational design input seismic wave is a very important factor in ensuring the reliability of the analysis and design. In the seismic design standards, rational design seismic waves must reflect the characteristics of the area (fault) and satisfy the design response spectrum for each seismic performance level. This requirement can be partially satisfied by modifying the actual seismic wave measured in the area (fault) according to the design response spectrum. In this study, a method of correcting and generating seismic wave time histories according to the design response spectrum based on actual measured seismic waves using the harmonic wavelet transform was proposed. To examine the applicability of the proposed technique, the technique was applied to earthquakes of magnitude 5.8 and 5.4, respectively, that occurred in Gyeongju (2016) and Pohang (2017), and the seismic wave time histories corresponding to the design response spectrum were modified and generated.

• Environmental and Resource Economics Review
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• v.31 no.2
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• pp.291-317
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• 2022

This study tried to analyze the factors affecting consumers' vehicle selection for the spread of eco-friendly vehicles. We used the energy census data for this purpose, and although the energy census collects useful information from a large number of samples, it has been limitedly used to create simple statistics in many cases. Based on 2,771 transport sector microdata from the 2017 Energy Census, we collected vehicle price, fuel efficiency, and number of vehicle models, which are alternative characteristic variables that change according to consumers' choice, and converted and analyzed data to enable conjoint analysis. The analysis results in two-folds. First, it was confirmed that the official fuel efficiency of a vehicle and the fuel cost, which is affected by changes in the relative price of each fuel, are important variables in selecting an eco-friendly vehicle. In order to achieve the goal of spread of eco-friendly vehicles, it is necessary to develop technologies to improve fuel efficiency and set appropriate electric rates for charging electric vehicles. Second, an increase in the number of vehicle models through the expansion of the eco-friendly car industry and market also affects consumers' choice of eco-friendly vehicles, so efforts to expand the supply of eco-friendly vehicles will be an important factor. In addition, it is also significant that this study showed that the use of the energy census can be diversified by deriving meaningful policy implications using the results of the energy census periodically conducted in the country without a separate survey.

• The Korean Journal of Franchise Management
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• v.9 no.2
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• pp.39-52
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• 2018

Purpose - This study investigates the effect of service quality of coffee shop on store attitude and store loyalty. It demonstrates that the individual's behavior identification level plays a moderating role when the service quality of coffee shop affects store attitude. Conceptually drawing on Brady & Cronin's three-dimensional model of service quality, this study examines the effect of service quality of coffee specialty store on customer's attitudes and loyalty. Also, according to construal level theory, it examines the individual's propensity difference whether the individual's behavior identification level on service quality and store attitude has a moderating effect Research design, data, and methodology - This study used Brady & Cronin's three-dimensional service quality model, and 183 valid cases collected through the questionnaire survey were used for data analyses. For hypothesis testing, regression analysis, multiple regression analysis, and covariance analysis were conducted. Result- As a result of this study, first, it is confirmed that service quality has a positive effect on store attitude toward coffee shop. Second, the difference of an individual's construal level did not have a moderating effect on the influential relationship of service quality on the store attitude of coffee shop. This is because the influence of the service quality is greater than the difference between groups at the construal level. Therefore, there was no moderating influence according to construal level. Third, the store attitude of coffee specialty store has a positive effect on store loyalty. Conclusions - It is confirmed that there is a difference in the effect of service quality and store attitude on general and college students. This suggests that it can be used to establish marketing strategies by segment. And, the college students were found to be more influenced by physical environment quality factor among three dimensions of service quality. Therefore, it is necessary to further improve efforts to raise the level of service quality perception through physical environmental factors such as clean and pleasant environment including the interior of a coffee shop, and internal table arrangement. The empirical study on the moderating effects of customer's tendency of difference is meaningful in the absence of empirical studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.41-47
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• 2006

The construction of traffic facilities has generated a variety of problems in the equality and efficiency when it would be planed and evaluated. One of the reasons for these phenomena isn't the definition of an objective standard about benefit items. Thus, results of evaluation couldn't give a demonstration of confidence. But, the traffic facility construction and its operation costs are securely appeared. Therefor, it will be demonstrated to decide the benefit items in this study. Before deciding the items, user's satisfaction evaluation and economic analysis would be carried. We find out subway user's satisfaction higher than load traffic mode user in satisfaction evaluation, while subway's economic feasibility is lower than load facility, as a result of B/C analysis. In this inconsistent results, we found out that the benefit value is a little lower because of indefinite standard of it's items as comparing Busan Metropolitan City's population with subway's modal split ratio. Accordingly, we enumerate some benefit items in the case of feasibility evaluation as constructing traffic facility. And each of evaluation items' weight is estimated by using ANP. We found out that the weight value of accessibility has the highest one, that of punctuality has second, that of travel time has third, and benefit items according to improvement of user's traffic condition have much more important than those which were considered in the existence economic analysis.

• Korean Journal of School Psychology
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• v.16 no.2
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• pp.89-110
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• 2019

This study is to verify relative influence of individual, parent, peer, teacher-related variables as protective factors and risk factors of academic hatred. Surveys were conducted with 1,015 (women, 57.3%) high school third grade students across eight schools where are located in Seoul, Incheon, and Geyonggi province. Correlation analysis and hierarchical multiple regression analysis were performed. The findings are summarized as follows. Teacher's academic pressure did not have significant correlation with student's basic psychological needs, teacher's autonomy support, teacher's support, and peer support whereas other variables showed significant correlation each others. The hierarchical multiple regression analysis indicated that student's individual competence and autonomy, parent's academic support, and teacher's emotional support work as protective factors and that parent's academic pressure functions as a risk factor. The effects of peer support disappeared when teacher-related factors were included. In addition, the effects of teacher's autonomy support disappeared, while the effects of teacher's support strengthened when learner's basic psychological needs were input. This study is meaningful in that it clarified academic hatred which had not been studied in other research and that it provided theoretical foundation for subsequent studies on academic hatred by examining relative influence of related variables. Lastly, it presented its limitation, implications on intervening strategies in school counseling, and suggestions for later studies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.173-191
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• 2022

The global economic crisis, the trend of an aging society, and the rapid digital transformation are huge burdens and crises for our society. Due to these environmental changes and the economic recession, entrepreneurship and re-employment issues after retirement have emerged as social issues. This study was conducted to empirically analyze what factors affect seniors when they may start a business. In particular, as the fourth industrial revolution progresses, the focus was on the capability to utilize information and communication technology (ICT) and digital media that cannot be avoided. For empirical analysis, an online survey of seniors was conducted and 287 valid samples were analyzed. SPSS 24.0 and Macro Process 4.0 were used for statistical analysis. As a result of the empirical analysis of this study, self-efficacy and personal innovation for information technology acceptance(ICT), and communication capability using digital media had a significantly positive (+) effect on senior's entrepreneurial intention. However, the perceived usefulness of information technology and the capability to utilize digital media devices were not tested for significance. Among the variables that had a significant effect, personal innovation was found to have the greatest effect. Opportunity recognition was found to play a mediating role between self-efficacy, personal innovation, communication capabilities, and senior's entrepreneurial intention. The results of this study are of academic and practical significance in that digital media utilization capability is also an influential factor among various factors influencing the entrepreneurial intention of seniors.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.11
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• pp.613-625
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• 2017

For two agricultural reservoirs that are rented for fishing spots, benthic nutrient fluxes experiment were performed two times with two sediments from fishing-effective zone and one sediment from fishing-ineffective zone using laboratory core incubation in oxic and anoxic conditions. During benthic nutrient fluxes experiment, the changes in DO, EC, pH, and ORP in the supernatant were not significantly different between fishing-effective zone and fishing-ineffective zone, and were similar to the sediment-hypolimnetic diffused boundary layer in agricultural reservoir. Except for $NO_3{^-}-N$, more benthic nutrient fluxes of $NH_4{^+}-N$, T-P, and $PO{_4}^{3-}-P$ from sediment to hypolimnetic was measured in anoxic than in oxic conditions (p<0.05). As the DO concentration in hypolimnetic decreases, the microorganism-mediated ammonification is promoted, the nitrification is suppressed, and finally the $NH_4{^+}-N$ diffuses out from sediment to hypolimnetic. Also, the diffusion of T-P and $PO{_4}^{3-}-P$ from sediments to hypolimnetic is accelerated through the dissociation of the phosphorus bound to both organic matters and metal hydroxides. The difference in the benthic nutrient diffusive fluxes between fishing-effective zone and fishing-ineffective zone was not statistically significant (p>0.05). Therefore, it was found that fishing activities did not increase the benthic nutrient diffusive fluxes to a statistically significant level. Due to the short fishing activities of 10 years and the rate-limited diffusion of the laboratory core incubation, the contribution of fishing activities on sediment pollution is estimated to be low. No significant correlation was found between the total amount of nutrients in sediment and the benthic nutrient diffusive fluxes in both aerobic and anaerobic conditions. Therefore, nutrients input from various nonpoint sources of watersheds are considered to be a more dominant factor rather than fishing activities in water quality deterioration, and both aeration and water circulation in hypolimnetic were required to suppress the anoxic environment in agricultural reservoirs.