• Particle and aerosol research
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• v.15 no.3
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• pp.91-104
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• 2019

In this study, hourly measurements of $PM_{2.5}$ and its major chemical constituents such as organic and elemental carbon (OC and EC), and ionic species were made between January 15 and February 10, 2018 at the air pollution intensive monitering station in Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were collected at the same site and analyzed for OC, EC, water-soluble OC (WSOC), humic-like substance (HULIS), and ionic species. Over the whole study period, the organic aerosols (=$1.6{\times}OC$) and $NO_3{^-}$ concentrations contributed 26.6% and 21.0% to $PM_{2.5}$, respectively. OC and EC concentrations were mainly attributed to traffic emissions with some contribution from biomass burning emissions. Moreover, strong correlations of OC with WSOC, HULIS, and $NO_3{^-}$ suggest that some of the organic aerosols were likely formed through atmospheric oxidation processes of hydrocarbon compounds from traffic emissions. For the period between January 18 and 22 when $PM_{2.5}$ pollution episode occurred, concentrations of three secondary ionic species ($=SO{_4}^{2-}+NO_3{^-}+NH_4{^+}$) and organic matter contributed on average 50.8 and 20.1% of $PM_{2.5}$, respectively, with the highest contribution from $NO_3{^-}$. Synoptic charts, air mass backward trajectories, and local meteorological conditions supported that high $PM_{2.5}$ pollution was resulted from long-range transport of haze particles lingering over northeastern China, accumulation of local emissions, and local production of secondary aerosols. During the $PM_{2.5}$ pollution episode, enhanced $SO{_4}^{2-}$ was more due to the long-range transport of aerosol particles from China rather than local secondary production from $SO_2$. Increasing rate in $NO_3{^-}$ was substantially greater than $NO_2$ and $SO{_4}^{2-}$ increasing rates, suggesting that the increased concentration of $NO_3{^-}$ during the pollution episode was attributed to enhanced formation of local $NO_3{^-}$ through heterogenous reactions of $NO_2$, rather than impact by long-range transportation from China.

• The Korean Journal of Franchise Management
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• v.10 no.2
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• pp.49-58
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• 2019

Purpose - As the growth potential of the cultural contents industry steadily grows, the cinemas industry is growing fast especially due to popularity and commerciality. The recent in the cinemas industry is evolving on multiplex cinemas that combine cultural facilities such as theaters, restaurants, and shopping centers. Due to the rapid growth of multiplex cinemas, many researchers have studied the characteristics of visiting customers in Korea. Among them, selection attribute of multiplex cinemas, including the service quality and physical environment, is important because it may examines the cause of customer 's behavior. Thus, this research focuses on the effects of the selection attributes of the multiplex cinemas on customer satisfaction and their loyalty. This research suggests the guidelines for how cinemas should manage their customers and build their customers satisfaction and loyalty that improve business performance. Research design, data, and methodology - This study tests the structural relationship between selection attributes of multiplex cinemas, customer satisfaction, and loyalty. selection attributes of multiplex cinemas divide into five sub-dimensions such as movies facility quality, services, cleanliness, accessibility, and snack bars quality. In order to examine the purposes of this research, research model and hypotheses were developed. All constructs were measured with multiple items developed and tested in the previous studies. The data were collected from 100 students in their 10-20s and were analyzed using SPSS 22.0, SmartPLS 3.0 and fsQCA program. Result - The findings of this research are as follows. First, all selection attributes except cleanliness have significant positive impacts on customer satisfaction and loyalty. Second, customer satisfaction has significant positive impact on loyalty. Third, as a result of fsQCA, high satisfaction and high accessibility were the necessary conditions on loyalty. Fourth, the necessary conditions for male and female groups were different. Conclusions - The implications of this study are as follows. Overall, multiplex cinemas should manage selection attributes basically regardless of the type of theater. Especially, cleanliness was not significant, but the customer probably consider it an essential and basic factors. Also, they are able to manage the selection attributes differently depending on the type of gender. For the male customers, it is effective that centralized strategy and for female customers, it is effective that emphasized the multiplex cinemas image.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.49-54
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• 2022

Rapid changes in modern society after the COVID-19 have highlighted artificial intelligence talent as a major influencing factor in determining national competitiveness. Accordingly, the Ministry of Education planned a large-scale SW·AI camp education project to develop the digital capabilities of 4th to 6th grade elementary school students and middle and high school students who are in a vacuum in artificial intelligence education. Therefore, this study aims to develop a camp-type SW·AI education program for students in grades 4-6 of elementary school so that students in grades 4-6 of elementary school can acquire basic knowledge in artificial intelligence. For this, the meaning of SW·AI education in elementary school is defined and SW·AI contents to be dealt with in elementary school are: understanding of SW AI, 'principle and application of SW AI', and 'social impact of SW AI' was set. In addition, an attempt was made to link the set elements of elementary school SW AI education and learning with related subjects and units of textbooks currently used in elementary schools. As for the program used for education, entry, a software coding learning tool based on block coding, is designed to strengthen software programming basic competency, and all programs are designed to be operated centered on experience and experience-oriented participants in consideration of the developmental characteristics of elementary school students. In order for SW·AI education to be organized and operated as a member of the regular curriculum, it is suggested that research based on the analysis of regular curriculum contents and in-depth analysis of SW·AI education contents is necessary.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.127-133
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• 2021

In this study, an augmented reality-based make-up tool was built to analyze the user's face shape based on face-type reference model data and to provide virtual makeup by providing face-type makeup. To analyze the face shape, first recognize the face from the image captured by the camera, then extract the features of the face contour area and use them as analysis properties. Next, the feature points of the extracted face contour area are normalized to compare with the contour area characteristics of each face reference model data. Face shape is predicted and analyzed using the distance difference between the feature points of the normalized contour area and the feature points of the each face-type reference model data. In augmented reality-based virtual makeup, in the image input from the camera, the face is recognized in real time to extract the features of each area of the face. Through the face-type analysis process, you can check the results of virtual makeup by providing makeup that matches the analyzed face shape. Through the proposed system, We expect cosmetics consumers to check the makeup design that suits them and have a convenient and impact on their decision to purchase cosmetics. It will also help you create an attractive self-image by applying facial makeup to your virtual self.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.27-35
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• 2021

The study intends to identify the effects of infrastructure property on an apartment house by analyzing the price variation affected by factors constituting the quality of the transit services of each individual station in urban railway system based on hedonic price model. The research findings indicate that the prices depending on the transit users have increased from 7.8% to 12.2% in Seoul and decreased from 6.1% to 12.9% in Gyeonggi, which implies that a lower number of transfer users has a positive effect on housing prices in Seoul unlike Gyeonggi. It also is noteworthy that the distance to the urban railway station had a negative effect on housing prices in Seoul and positive effect in Gyeonggi. Taking these results together, in Seoul, the increase in the number of transit users had a negative effect on neighborhood housing prices. When analyzed by segments, however, an additional negative effect was observed only in the apartments located within the radius of 100 meters. It is also found that the impact of transit users varies according to the regional characteristics, such as the density of commercial facilities and the population density, and the spatial extent of negative effect also showed regional differences. These results provide implications for the planning of new stations, new cities, and land use of existing areas around stations.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.95-106
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• 2021

Side-jets enable the immediate maneuver of a missile compared to control surfaces; however, they may cause adverse effects on aerodynamic coefficients, for they interfere with freestream. To find out the impact of side-jets on aerodynamic coefficients, we simulate side-jets as air gas and utilize multi-fidelity models to evaluate differences between aerodynamic coefficients obtained with and without side-jets. We computed differences in aerodynamic coefficients to investigate side-jet effects for the changes of a Mach number, a bank angle, and an angle of attack. As a result, asymmetrically developed side-jets affect the longitudinal force and moment coefficients, and the lateral force and moment coefficients drastically change in-between -30 and 30 degrees of bank angles. In contrast, side-jets hardly influence the axial force coefficients. As for the axial moment coefficient, we could not determine the side-jet effect due to a lack of aerodynamic coefficient samples in the Mach number. All in all, we confirm that side-jets lead to the change of a missile attitude as they considerably vary the longitudinal and lateral aerodynamic coefficients.

• Structural Engineering and Mechanics
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• v.76 no.6
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• pp.687-708
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• 2020

Openings in steel plate shear walls (SPSWs) are usually used for decorative designs, crossing locations of multiple utilities and/or structural objectives. However, earlier studies showed that generating an opening in an SPSW has a negative effect on the cyclic performance of the SPSW. Therefore, this study proposes tripling or doubling the steel-sheet-plate (SSP) layer and stiffening the opening of the SPSW to provide a solution to undesirable opening effects, improve the SPSW performance and provide the infill option of potential strengthening measures after the construction stage. The study aims to investigate the impact of SSP doubling with a stiffened opening on the cyclic behaviour, expand the essential data required by structural designers and quantify the SPSW performance factors. Validated numerical models were adopted to identify the influence of the chosen parameters on the cyclic capacity, energy dissipation, ductility, seismic performance factors (SPF) and stiffness of the suggested method. A finite Element (FE) analysis was performed via Abaqus/CAE software on half-scale single-story models of SPSWs exposed to cyclic loading. The key parameters included the number of SSP layers, the opening size ratios corresponding to the net width of the SSP, and the opening shape. The findings showed that the proposed assembly method found a negligible influence in the shear capacity with opening sizes of 10, 15, 20%. However, a deterioration in the wall strength was observed for openings with sizes of 25% and 30%. The circular opening is preferable compared with the square opening. Moreover, for all the models, the average value of the obtained ductility did not show substantial changes and the ultimate shear resistance was achieved after reaching a drift ratio of 4.36%. Additionally, the equivalent sectional area of the SSP in the twin and triple configuration of the SPSWs demonstrated approximately similar results. Compared with the single SSP layer, the proposed configuration of the twin SSP layer with a stiffened opening suggest to more sufficiency create SSP openings in the SPSW compared to that of other configurations. Finally, a tabular SPF quantification is exhibited for SPSWs with openings.

• The Korean Journal of Franchise Management
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• v.12 no.2
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• pp.7-21
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• 2021

Purpose: One of the characteristics of service companies such as foodservice franchise is that it is easy to imitate, so many brands can imitate the menu that is popular with consumers. Therefore, foodservice franchise company should develop a brand that customers can identify from other brands in order differentiate it from its competitors. In order make the foodservice franchise company identifiable from other brands, it is possible through communication with customers. Therefore, this study proposes a new research model to analyze customer loyalty through online advertising and online word of mouth trust and immersion. Online was provided to customers through a mixture of advertisements and word of mouth, but previous studies have only considered online advertisements or online word of mouth. In addition, we want to verify the difference according to gender, which is an important variable in researching the online information processing behavior of customers. Research design, data, and methodology: The questionnaire of this study was surveyed on 20 years of age or older who have visited the restaurant franchise store within the last 3 months among the foodservice franchise companies operating SNS. During the survey period, 400 surveys were surveyed for a total of 20 days from April 1 to April 20, 2020. Result: The research results are as follows. First, in this study, the effect of online advertisement and online word of mouth on trust and immersion was studied. Second, this study verified the social influence theory in online advertising and online word of mouth. Third, the effect of online advertising and online word of mouth on loyalty according to gender was verified. Fourth, compared to existing advertisements, online advertisements are suitable for marketing by foodservice franchise companies because they can interact with consumers, modify advertisements immediately, execute extensive advertisements at low cost, segment the market, and measure advertisement effectiveness. The recent online expansion has been expanded to mobile-based, allowing foodservice franchisees to provide new communication services such as SMS (Short Message Service), multimedia messaging services, and location-based services. Fifth, a foodservice franchise company can increase brand awareness through online marketing or induce the use of offline stores. Sixth, franchisor can grow into a sustainable company only when they use resources efficiently. Conclusions: Trust is important in foodservice franchise information. This trust has a significant impact on customer commitment and loyalty.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.61-70
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• 2011

The impact protection system consists of an arrangement of circular sheet pile cofferdams-denoted dolphin structuredeeply embedded in the seabed, filled with crushed rock and closed at the top with a robust concrete cap. Centrifuge model tests were performed to investigation the behaviors of dolphins in this study. Total 7 quasi-model tests and 11 dynamic model tests were performed. The main experimental results can be summarized as follows. Firstly, The experimental force-displacement results for quasi-static tests show a limited influence on the initial stiffness of the structure from the change in fill density and the related change in the stiffness of the fill. And by comparing the dissipation at the same dolphin displacement it was found that the denser fill increase the dissipation by 16% for the 20m dolphin and by 23% for the 30m dolphin. The larger sensitivity for the large dolphin is explained by a larger contribution to the dissipation from strain in the fill. In low level impacts the dynamic force-response is up to 26~58% larger than the quasi-static and the dissipation response is showed larger in small displacement. Hence, it is concluded conservative to use the quasi-static response characteristics in the approximation of the response, and it is further concluded that the dolphin resistance to low level impacts is demonstrated to be equivalent and even superior to the high level impacts.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.13-20
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• 2011

There are many mountains in Korean Peninsula, and those used for the construction of roads and railways sectors are forming slopes. Slope collapse occurs with falling rocks and landslide because of the relaxation of the thawing rocks. The heavy rain in summer can also significantly contribute to the process, and abnormal climate change is much more influential than before. Therefore, rockfall-related accidents in rainy season are easily accessible in media every year. There has been a lot of research on application of strengthening compensation of the sections in order to minimize casualties and property damage. Rockfall Protection Net, however, has not been focused on much in the field yet. This study highlights the need of Rockfall Protection Net, since it can segregate the falling rocks inside the net relatively safely. Although there has been a little doubt about the effectiveness of rockfall protection facilities, it is obvious that relevant studies dealing with the solidity of the net are necessary for the rockfall protection net to be capable of supporting rockfall energies. As a result, Expanded metal strength is much more durable compared to the PVC coating net, and it is regarded as an excellent alternative material for the Rockfall Protection Net. In this study, the applicability of Expanded Metal as the alternative of Rockfall Protection Net is verified experimentally.