• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.545-561
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• 2003

We use the first-passage-time formulation by Torquato, Kim and Cule ［J. Appl. Phys., Vol. 85, pp. 1560∼1571 (1999) ］, which makes use of the first-passage region in association with the diffusion tracer's Brownian movement, and develop a new efficient Brownian motion simulation method to compute the effective conductivity of digitized composite media. By using the new method, one can remarkably enhance the speed of the Brownian walkers sampling the medium and thus reduce the computation time. In the new method, we specifically choose the first-passage regions such that they coincide with two, four, or eight digitizing units according to the dimensionality of the composite medium and the local configurations around the Brownian walkers. We first obtain explicit solutions for the relevant first-passage-time equations in two-and three-dimensions. We then apply the new method to solve the illustrative benchmark problem of estimating the effective conductivities of the checkerboard-shaped composite media. for both periodic and random configurations. Simulation results show that the new method can reduce the computation time about by an order of magnitude.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.209-215
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• 2023

The untact environment brought about by the global pandemic has emerged as a new driving force for the matured social media market. In the post-coronavirus era, there arises a pivotal need for foundational data to reconfigure the operations and utilization strategies of social media. Using data from the 2022 Korean Media Panel Survey, this study compared sociodemographic and personality factors between social media non-users and users, and examined how these factors influenced social media usage time. The findings indicate differences between social media non-users and users in terms of gender, age, education level, income level, employment status, marital status, openness to experience, conscientiousness, extraversion, and neuroticism. Usage time of social media is influenced by gender, age, income level, employment status, conscientiousness, and agreeableness. These results are anticipated to enhance the understanding of users and their usage behaviors for stakeholders in the social media market as they confront a potential second leap forward.

• Asian Journal for Public Opinion Research
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• v.11 no.1
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• pp.4-30
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• 2023

Previous research has empirically demonstrated the negative effects of social media use on young people's psychological well-being. Unlike most previous studies that focused on either Facebook or Instagram, this study comparatively examined the differences in upward comparison and its effects on self-esteem, life satisfaction, and depression between Facebook and Instagram. An analysis of survey data from 641 Korean college students, who reportedly use these two social media more actively than any other age group, found that college students experience more upward comparisons on Instagram than on Facebook. Upward comparisons on both Facebook and Instagram increased by college students' age and weekly usage time. Upward comparisons on Instagram increased by the additional factors of gender (females more than males) and number of "followings." Subsequently, the effects of upward comparison on psychological well-being were found to differ by social media platform. Upward comparisons were found to negatively impact all determinants of psychological well-being only on Instagram, but not on Facebook. The differences in upward comparison and its impact on young users' psychological well-being found in this study were discussed in terms of the different functional characteristics of the two social media platforms, which provides direction for further research needed to establish guidelines for healthy social media use by young people.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.2
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• pp.17-22
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• 2008

It is to improve customer satisfaction measurement and CT Scan process without delay of examination time when is using Scan positioning time(Planning time) that time is happened always between research reactor CT examination to increase fear and examination satisfaction by the customer's comprehension tribe which get the latest contrast enhancement CT examination. Needs and interests that customer wants to compose visual and auditory Contents to be played to Scan positioning time did questionnaire about curiosity later before CT examination to 600 people for October - November 2 months of 2006 to customer whole that get CT examination on source. Data getting through questionnaire investigated examination comprehension and satisfaction through questionnaire after experiment Scan Positioning to 500 coming to help customers to be source CT examination for 3 months February December - 2007 year in 2006 manufacturing Voice and Visual announce media for reference. To customer who interest degree appeared, and answers preparatory audit from preparatory audit about curiosity of CT examination customer to order of examination time required(43%), contrast media side effect(26%), examination region(20%), breath(10%), etc..(1.5%) audio-visual materials in questionnaire that attain after do reclamation among examination age, sex, reception type of irrelatively in 91% of target increase of hailing degree and examination satisfaction appear. Searched that customer hailing and satisfaction are increased greatly when use of audio-visual materials in satisfaction result that use CT Positioning delay time. In experiment process, It took lacking part by method that use hearing in case of do not use sight as is unavoidable in subject position or old age. Through this, audio-visual materials could analogize that it is more useful method that use sight and hearing at the same time.

• Journal of Broadcast Engineering
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• v.26 no.5
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• pp.583-591
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• 2021

This paper explores variables that influence the prediction of OTT service experience and free(AVOD)/ paid(SVOD) service use. Research results showed that five variables such as gender, age, personal income, household composition, and e-commerce use experience had a significant impact on identifying OTT service experience and whether to use free or paid services. Also, it was found that the probability of using SVOD increases as they prefer news and drama genres and use OTT services for more time. In summary, those who are relatively young, have a high personal income, and are more adapted to digital environments such as e-commerce are more likely to use SVOD.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.210-218
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• 2016

In this study VOD usage patterns(VOD use and paid amount) of IPTV users were investigated reflecting the level of media use characteristics such as TV viewing time, star preference, and genre preference. Also the impact of media using characteristics and the evaluation of guide channel on the intention to use VOD was analyzed. The web survey was conducted against the respondents who have used VOD and guide channel. The results are as follows. Among the media usage characteristics, star preference has the impact on the VOD use, while genre preference has relation to the willingness to pay for VOD. Secondly, the intention to view the guide channel, entertainment of the channel, and the users' genre preference have significant impacts on the intention to use VOD. Therefore, it is necessary to raise the viewing rate of guide channel by providing the customized promotion strategy and diverse events based on the analysis of VOD usage.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.255-260
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• 2013

This study was attempted to identify the differences of mental health and media use according to the addiction of communication media. Data collection was surveyed using interview and questionnaires by 250 subjects from March 12 to May 13, 2012. The results were as follows : First, with regard to mobile phone use time for communication in the use of over 2 hrs, subjects replied that addictive group was significantly higher than non-addictive group($X^2$=8.51, p=.00). Secondly, in case often depression, the risk ratio of addictive group was significantly higher 4.0 times than non-addictive group(OR=4.0, 95%, Cl=2.4-36.9). In conclusion, in order to prevent the addictive use of communication media, it is needed to make various environment such as sound life rhythm maintenance, systemic and periodic education.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.93-100
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• 2017

In multi-media, multi-channel era, video viewing using various digital devices via the Internet, not the existing broadcasting network, is emerging as a new broadcasting viewing behavior. OTT service is regarded as the main service of this change of viewing behavior. It is a video service that can seamlessly use any content desired by the user at any time, at any time, any device, any contents, if the Internet connection is available. The purpose of this study is to investigate the factors affecting the satisfaction of OTT service by applying the technology acceptance model (TAM). As a result of analyzing through 303 questionnaires of the early users of OTT service, social pressure, perceived popularity, perceived cost, user reputation, individual innovation, and esthetics set as external factors in this study are partially affects perceived usefulness, perceived ease of use, and perceived enjoyment. In addition, perceived usefulness, ease of use, and enjoyment are directly influencing satisfaction. Based on these results, we discuss the theoretical and practical implications and propose future research direction.

• Korean journal of communication and information
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• v.38
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• pp.40-72
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• 2007

Amid the rapid growth in use of portal news, this study examined whether portal news would substitute traditional news media, in particular newspapers and television news. To answer the research question, this study attempted to investigate how the decrease in use of traditional news media was associated with online news use, reliance on, and motivations for portal news. First, this study found that there was a negative and significant relationship between the Internet use and television news viewing, suggesting that those who are more likely to use the Internet are less likely to watch television news programs. Also, portal news was negatively associated with time spent with newspaper reading, while it was not related to television news viewing. Second, this study found that convenience/information-seeking needs appeared as the major motivations for using portal news, which were negatively and significantly associated with the decreased time spent with watching television news programs. In other words, those who used portal news for convenience/information-seeking needs are less likely to watch television news programs, which may indicate that portal news could be a substitute for television news in terms of convenience/information-seeking motivations. In addition, the result of this study showed that there was a complementary relationship between portal news and newspapers in terms of surveillance needs. Those findings could be explained by the concept of "functional similarity" in the process of media substitution. Based on the findings, implications of this study were discussed.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.85-96
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• 2024

As users of paid media readers' satisfaction with usage directly affects the promotion and development of paid media in China. Based on relevant research literature on user sustained use behavior, using the Expectation Confirmation Model as the framework, China paid media Caixin is used as a content product to construct a sustained use model for paid media. At the same time, the operational definition and theoretical assumptions of the variables in the model were provided, laying the foundation for subsequent empirical research on the effectiveness of the model.The research results show that paid media's social influence and performance expectations have a positive impact on Caixin App readers' adoption behavior,perceived usefulness and expection confirmation has a positive impact on Caixin App readers' satisfaction . Adoption behavior and satisfaction has a positive effect on continue using intention, what's more,the perceived usefulness also has a positive effect on continue using intention.