• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.110-115
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• 2005

A novel technique for fine particle beam focusing under the atmospheric pressure is introduced using a radiation pressure assisted aerodynamic lens. To introduce the radiation pressure in the aerodynamic focusing system, a 25m plano-convex lens having 2.5mm hole at its center is used as an orifice. The particle beam width is measured for various laser power, particle size, and flow velocity. In addition, the effect of the laser characteristics on the beam focusing is evaluated comparing an optical tweezers type and pure gradient force type. For the pure aerodynamic focusing system, the particle beam width was decreased as increasing particle size and Reynolds number. Using the optical tweezers type, the particle beam width becomes smaller than that of the pure aerodynamic focusing system about $16\%,\;11.4\%\;and\;9.6\%$ for PSL particle size of $2.5{\mu}m,\;1.0{\mu}m,\;and\;0.5{\mu}m$, respectively. Particle beam width was minimized around the laser power of 0.2W. However, as increasing the laser power higher than 0.4W, the particle beam width was increased a little and it approached almost a constant value which is still smaller than that of the pure aerodynamic focusing system. For pure gradient force type, the reduction of the particle beam width was smaller than optical tweezers type but proportional to laser power. The radiation pressure effect on the particle beam width is intensified as Reynolds number decreases or particle size increases relatively.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.209-216
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• 2010

The purpose of this paper is to examine a user's flow experience of digital contents. In the paper, the flow experience of digital contents was applied to the case of online games and it was experimentally investigated whether challenge and skill affect the user's flow experience. The results of the paper indicate that there are differences in the flow experience according to the level (low, medium, high) of challenge and skill in the context of online games. Furthermore, there is no interaction effect between challenge and skill affecting flow experience. The findings provide useful implications for IT firms that will plan to develop and design digital contents.

• International Journal of Fluid Machinery and Systems
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• v.8 no.3
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• pp.124-131
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• 2015

The good performance of a vortex shedder is defined by strong and stable vortex generated under the condition of most linearity in Strouhal number and low power loss. In this paper, the flow past a bluff body of circular cylinder with a slit normal to the flow has been analyzed focusing on drag coefficient, linearity of Strouhal number and flow resistance (K-factor). The ANSYS/FLUENT package is used for flow simulation and the integration method of computational code to iSIGHT platform is employed for automated design cycle. This study results the design with (0.20~0.267) blockage ratio and 0.10 slit ratio as the best shedder for vortex flowmeter and this results are in well agreement with the experiment. As the combination of GAMBIT, FLUENT, and iSIGHT substitutes the design parameters automatically according to the input data, this method designs effectively the vortex shedder with less design cycle time and low manufacturing cost eliminating the human intervention bottleneck.

• Journal of Information Technology Services
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• v.11 no.1
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• pp.247-272
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• 2012

Social Network Service(SNS) is a kind of advanced Internet service that acts as personal media. This study was intended to find out the structural relationships among factors affecting the usage of social network services by extending the Technology Acceptance Model(TAM). For this purpose, the variable 'Flow' was first integrated into the TAM in order to understand the internal motivations of users. And then the external factors of SNS usage were derived from the perspective of users, contents, and media side of SNS, and finally the dependent variable was set with the intention of sustainable use. Then these factors were carefully integrated into a structural model. We expect the findings of this study will be very helpful for the internet marketing professionals, SNS developers, and the others.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.171-179
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• 2016

An online community serves as a communication hub among members who desire to share their opinions and emotions. Thus, it is often utilized as a corporate or brand marketing tool. While focusing on commercial online communities from the marketing perspective, however, researchers have barely discussed non-commercial online communities despite its popularity. This study examined the influence of flow on satisfaction in the context of the non-commercial online community as well as the role of social capital as a significant mediator between flow and satisfaction. The result also included the differences between employed mothers and non-employed mothers. This study has expanded the research scope of online communities and offered theoretical and practical implications based on the interdisciplinary discussion that involves one of the understudied populations, mothers.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.159-167
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• 2019

This study investigated the factors affecting the satisfaction of augmented reality (AR) fashion application focusing on user experience. The survey was conducted on 280 Chinese users who had used AR fashion applications. The results are summarized as follows. User experience had a significant effect on presence, flow, and satisfaction. Personalization service also increased user satisfaction. Presence influenced flow which enhanced satisfaction, indicating that presence had an indirect effect on satisfaction through flow. The results are expected to provide strategic implications by identifying factors that should be considered to help consumers experience products and improve satisfaction with applications in various industries focusing on augmented reality technology.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.6
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• pp.1-13
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• 2023

Irrigation return flow plays an important role in river flow forecasting, basin water supply planning, and determining irrigation water use. Therefore, accurate calculation of irrigation return flow rate is essential for the rational use and management of water resources. In this study, EPA-SWMM (Environmental Protection Agency-Storm Water Management Model) modeling was used to analyze the irrigation return flow and return flow rate of each intake work using irrigation canal network. As a result of the EPA-SWMM, we tried to estimate the quick return flow and delayed return flow using the water supply, paddy field, drainage, infiltration, precipitation, and evapotranspiration. We selected 9 districts, including pumping stations and weirs, to reflect various characteristics of irrigation water, focusing on the four major rivers (Hangang, Geumgang, Nakdonggang, Yeongsangang, and Seomjingang). We analyzed the irrigation period from May 1, 2021 to September 10, 2021. As a result of estimating the irrigation return flow rate, it varied from approximately 44 to 56%. In the case of the Gokseong Guseong area with the highest return flow rate, it was estimated that the quick return flow was 4,677 10³ m³ and the delayed return flow was 1,473 10³ m³ , with a quick return flow rate of 42.6% and a delayed return flow rate of 13.4%.

• Journal of Service Research and Studies
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• v.12 no.4
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• pp.30-49
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• 2022

Recently, as the transition to the untact era due to COVID-19 accelerates, non-face-to-face and non-contact practices have become commonplace, and the OTT (Over-The-Top) service market that provides media content such as movies and broadcast programs through the open Internet is largely expanded and it is receiving great attention from the MZ generation, who are familiar with digital devices and environments. In this study, the effects of OTT service characteristics on MZ generation users' flow, satisfaction and brand loyalty were examined, focusing on Netflix users, one of the representative OTT service brands. In order to carry out this study, a total of 216 people who have used the Netflix OTT service platform were empirically verified by using the survey data of those who have used it for analysis. As a result of the analysis, it was found that among the characteristics of OTT service, contents diversity, convenience, and reliability had a positive (+) effect on flow. Also, flow has a positive (+) effect on satisfaction, and satisfaction has a positive (+) effect on brand loyalty. However, among the characteristics of the OTT service, the recommended service did not have a positive (+) effect on the flow, and the flow did not have a direct positive (+) effect on the brand loyalty. Flow had a positive (+) effect on the brand loyalty through satisfaction. Through this study, it is expected that the market revitalization of the OTT service-related industry and the increasing number of OTT service brands will be able to contribute to the establishment of marketing strategies for the MZ generation consumers, and to provide practical implications.

• Korean Journal of Childcare and Education
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• v.18 no.6
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• pp.37-57
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• 2022

Objective: The purpose of this study was to investigate whether parent's play participation and children's friendly play initiative affect children's executive function through children's play flow. Methods: The survey was conducted on 376 children between the age of 3 and 5 their parents in Daegu city and Gyeonsang province. Data were collected through the questionnaires and analyzed using descriptive statistics, independent sample t-test, one-way ANOVA, Pearson correlation analysis, and path analysis with SPSS 25.0 and AMOS 23.0 programs. Results: The major results were as follows. First, There were significant differences in parent's play participation, children's friendly play initiative, children's play flow, and executive function according to the children's age and family income. Second, parent's play participation and children's friendly play initiative indirectly affected children's executive function through children's play flow. Conclusion/Implications: This study highlights how children's play affects executive function. Also, the findings of this study will contribute to designing various programs that can promote parent's play participation, children's friendly play initiative, and play flow, which affects the children's executive function.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.1
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• pp.111-126
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• 2024

The purpose of this study is to analyze the mediating effect of flow in the quality of customizing e-services and customer loyalty, with a view to providing a realistic strategy for the development of fashion customizing services. For this study, a total of 489 adult women in their 20s and older participated in a survey, and the responses were analyzed using SPSS 23.0 and AMOS 23.0 . The findings of the analysis were as follows. First, the ease of use, privacy, individual designs, order status, and accuracy of orders, which were the factors of fashion customizing e-service quality, had a significant and positive impact on flow. Second, the ease of use, order status, and order accuracy, which were the factors of fashion customizing e-service quality, had a significant and positive impact on customer loyalty. Third, the flow of the fashion customizing service had a significant and positive impact on customer loyalty. Fourth, in the relationship between fashion customizing e-service quality and customer loyalty, flow had a significant mediating effect. The findings of this study are expected to be useful data for the fashion industry providing a set of criteria for optimized customizing e-services for customers.