• YAKHAK HOEJI
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• v.47 no.6
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• pp.432-437
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• 2003

It has been known that quercetin, a bioflavonoid widely distributed in fruits and vegetables as dietary-derived flavonoid and exert significant multiple biological effects such as antioxidant and anti-inflammatory, anti-tumor effects. In addition, it has been shown to have a chemoprotective role in cancer, though complex effects on signal transduction involved in cell proliferation and angiogenesis. The present study investigated whether quercetin can enhance antioxidant enzyme activity (glutathione peroxidase: GPx, superoxide dismutase: SOD, catalase: CAT) and regulate the reactive oxygen species (ROS) generation in the presence of vitamin E, L-ascorbic acid, reduced glutathione (GSH) on B16F10 murine melanoma cells. After 48h treatment of cells with quercetin in the presence of vitamin E, L-ascorbic acid, GSH, we measured the cytotoxicities by MTT assay. The cells exhibited a dose-dependent inhibition in their proliferation in the presence of vitamin E, L-ascorbic acid, GSH respectively. We also investigated the effects of antioxidant enzyme activity and ROS generation. The antioxidant enzyme activity of quercetin in the presence of vitamin E was stronger than GSH, L-ascorbic acid, the same treatments decreased ROS generation in B16F10 murine melanoma cells. Taken together, these result demonstrate that the antioxidant effect of quercetin can enhanced in the presence of vitamin E and it might plays an important role in anti-oxidative effects.

• Smart Media Journal
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• v.13 no.1
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• pp.76-85
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• 2024

This study examined the Presence experience, resulting effects, and re-viewing intentions of visitors to experiential exhibition content. For this purpose a survey was conducted targeting 246 visitors to experiential exhibition content based on Hyecho's travel story and SilkRoad cultural heritage. As a result of the survey, understanding and interest in the content material and similar exhibition viewing experience did not affect Presence experience. In addition the higher the Presence experience of exhibition content, the greater the awareness and emotion that is the effect of Presence. And among the effects of Presence, emotion had a positive effect on revisiting intentions. Therefore, it was confirmed that future experiential exhibition contents require planning, production, and exhibition that allow users to experience Presence.

• Educational Technology International
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• v.22 no.1
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• pp.1-21
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• 2021

This study examined the effects of egocentric distance and screen size on learners' perceived virtual presence in a virtual reality environment with a large-screen display. Sixty-four undergraduate students participated in the study, which used a 3×2 randomized-block factorial design with repeated measures. Two independent variables were included: 1) egocentric distance, or the physical distance between the viewer's position and a screen display, and 2) screen size, or different screen heights with fixed width. Learners' perceived virtual presence, comprising involvement, spatial presence, and realness, was the dependent variable. Results showed that egocentric distance had significant effects on virtual presence, while screen size had none. A detailed discussion and implications are provided.

• (The) Korean Journal of Advertising
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• v.29 no.7
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• pp.7-27
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• 2018

This study explored the effects of three-wall (3-W) movie screen on advertisement viewers' feelings of physical presence, perceived pleasure, and evaluation of advertisements. The findings from an experiment (N = 188) in a real movie theater demonstrate that 3-W screen enhances the feelings and perception toward the advertisements, with physical presence presenting the mediating effects. Of note is that the effects of 3-W screen were presented differently depending upon the types of the advertisements; the dynamic one and the static one. The effects were mostly applied to the dynamic advertisement, but not to the static one. Given the high costs of installing 3-W screen in movie theaters, the study's findings suggest more elaborate designs of advertisements to enhance the applicability of 3-W screen.

• Journal of Engineering Education Research
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• v.27 no.2
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• pp.13-24
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• 2024

This research aims to examine the effects of engineering students' self-regulated learning strategies on writing self-efficacy, perceptions of writing feedback, and learning presence. To achieve this purpose, firstly, differences in self-regulated learning strategies, writing self-efficacy, perceptions of writing feedback, and learning presence were investigated among engineering and non-engineering students. Secondly, the effects of self-regulated learning strategies, as perceived by engineering students, on writing self-efficacy, perceptions of writing feedback, and learning presence were explored. A total of 196 engineering and non-engineering students from one university in Korea responded to a survey based on a four-variable scale. The findings were as follows: firstly, there were significant differences in self-regulated learning strategies, writing self-efficacy, perceptions of writing feedback, and learning presence by major. Secondly, positive correlations between self-regulated learning strategies, writing self-efficacy, perceptions of writing feedback, and learning presence were identified in terms of sub-factors of those variables. Thirdly, engineering students' self-regulated learning strategies predicted writing self-efficacy, perceptions of writing feedback, and learning presence. The practical implications of these findings are discussed herein, with particular attention to education for the promotion of self-regulated learning strategies and their application to writing courses, as well as diverse learning environments.

• Korean Institute of Interior Design Journal
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• v.17 no.5
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• pp.166-174
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• 2008

As the use of virtual environment for decision-making interior or architectural design has been increasingly broaden, the choice of media form-physical, objective properties of a display medium-became and important issue to take into consideration. This research deals with the effects and differences between two types of media for a virtual environment; wall projection screen(120") and PC monitor(17"). In addition, efficient adoption of the two media forms was also proposed in this research. A total of 90 subjects participated in pre-designed three experimental groups(A group: experiment with a wall projection screen, B group: experiment with PC monitor, C group: both) and answer the seating preferences, the presence inventory, and the decision confidence using a simulated virtual restaurant environment. The results are as follows: (1) seating preferences for the tables located in frequent traffic area and near other spaces such as restroom and th kitchen are significantly different by the media form. While there is no significant difference found in seating preferences for most tables except high traffic areas near entrances between the two media. This result demonstrates the effects of media type or screen size on user perception for the areas near structural or interior design elements. (2) The presence measure in this research consist of in this research consist of four factors: 'spatial presence,' 'object presence,' 'positive effects,' and 'the factor of negative effects. 'The mean values of the items involving engagement or interaction in the spatial presence factor and the object presence factor are significantly different by the media form. A higher sense of presence of presence was observed in the wall projection screen. (3) PC monitor condition was shown to provide a higher level of decision confidence. Based on the research finding, conclusions and implications are discussed.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.489-497
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• 2020

The introduction of self-service technologies (SSTs) in retail stores aims to provide customers with a more satisfying shopping experience. Many retailers are increasingly turning toward the adoption of self-service technologies in providing services directly to customers. Given that previous SST research has focused mainly on the impact of the introduction of SST on customer responses, the present study explored the impact of the presence of employees in the relationship between SST and customer responses. Based on the two ground theories, motivation-based theories of behavior and social impact theory, this study tested the relationships between shopping motivations, SST use intention, and retailer attitude. Moderating effects of the presence of employees on the three relationships were also tested. Data were collected using an online survey and analyzed through structural equations modeling. Test results showed that both hedonic and utilitarian shopping motivations effect on SST use intentions, and SST use intentions effect on retailer attitude, subsequently. Although the presence of employee did not moderate the relationship between shopping motivations and SST use intentions, the employee presence moderated the relationship between SST use intentions and retailer attitude. The impact of SST use intentions on retailer attitude was higher in the high presence of employee group than in the low group.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.822-826
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• 2012

This study practically analyzed the relationships of safety awareness and safety practice of the day-care teacher according to the presence of CCTV and in particular, made a practical analysis about whether safety awareness have mediation effects in the relationship between presence of CCTV and safety practice. As a result of T-test analysis, safety awareness and safety practice of the day-care teacher according to the presence of CCTV is different that has been verified. As a result of regression analysis, safety awareness were positively related to safety practice. That is to say, even the mediation effects that the presence of CCTV through safety awareness related to safety practice were verified. As a result, it was concluded that safety awareness factors didn't play mediator roles between presence of CCTV and safety practice.

• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1189-1198
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• 2019

The study explores the effects of recording and viewing distances in stereoscopic 3D on presence, perceptual characteristics, and negative experiences. Groups of 20 participants were randomly assigned to each of the three viewing distances, and all participants were exposed to five versions of the stereoscopic 3D music video that differs in recording distance. The results showed that first, viewers felt a higher experience of presence and had a better perception of objects positioned near the cameras. Second, viewers felt a greater perception of screen transmission as the viewing distance increased. Finally, viewers felt a greater negative experiences due to the joint effects of recording and viewing distance. As investigating the influence of stereoscopic 3D content and viewing environments on psychological factors, the study expects to provide a guideline of human factors in 3D.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.169-175
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• 2015

The purpose of this study is to investigate the structural relationships among teaching presence, cognitive presence, social presence, service quality, learning flow, and learners' satisfaction in mobile learning. Survey data collected by 255 learners who completed mobile-supported courses offered by an online university in South Korea were analyzed using structural equation modeling. The results suggest that cognitive presence, social presence, and service quality have direct effects on learning flow, and that cognitive presence, service quality, and learning flow have direct effects on learners' satisfaction.