• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.628-644
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• 2021

The main purpose of this study is to search for variables that influence the perception of news of YouTube current affairs and political channel users. Existing studies have focused on providing normative criticism by examining the public opinion influence of YouTube channels, which play a role similar to the media, in terms of political polarization, fake news, and confirmation bias. However, this study attempts to examine the changes and meanings of users' perception of news with the advent of YouTube. To this end, an online survey was conducted for users with experience in using YouTube's current affairs and political channels. As a result of the study, it was found that the news perception of YouTube current affairs and political channel users was mixed with the perception of news from the perspective of professional journalism and the perception of newly added news in the digital environment. Based on these results, the researcher examined the implications of the professional news media's response direction to the platform environment.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.100-111
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• 2021

This study aims to lead the new discussion by looking at variables affecting the number of subscription channels and subscription satisfaction in the absence of academic discussion of users' YouTube subscriptions. To this end, we conducted an online survey and analyzed the factors affecting the number of subscription channels and subscription satisfaction of YouTube users. We conducted hierarchical regression to examine their subscription motivation with exploratory factor analysis and to examine the impact of subscription motivations and the intentionality of Youtubers and the usefulness of YouTube knowledge on the number of subscription channels and subscription satisfaction. The analysis results are as follows: First, YouTube's usage and convenience motivation have had a static impact on the number of subscription channels. Second, factors affecting subscription satisfaction have been shown to be convenience subscription motivation, communication with Youtubers motivation, and perceived usefulness of YouTube. The practical significance of this work is that it can be beneficial to platform and channel operators in the changing new media environment. Furthermore, it aims to expand the interaction research extensions between YouTuber and users in the new media environment.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.19 no.1
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• pp.27-35
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• 2023

Pressure tubes are the main components of PHWR core and serve as the pressure boundary of the primary heat transport system. However, because pressure tubes have changed their geometrical dimensions under the severe operating conditions of high temperature, high pressure and neutron irradiation according to the increase of operation time, all dimensional changes should be predicted to ensure that dimensions remain within the allowable design ranges during the operation. Among the deformations, the diameter expansion due to creep leads to the increase of bypass flow which may not contribute to the fuel cooling, the decrease of critical channel power and finally the deration of the power to maintain the operational safety margin. This study is focused on the modeling of the expansion of the pressure tube diameter based on the operating conditions and measured diameter data. The pressure tube diameter expansion was modeled using the neutron flux and temperature distributions of each fuel channel and each fuel bundle as well as the measured diameter data. Although the basic concept of the current modeling approach is simple, the diameter prediction results using the developed methodology showed very good agreement with the real data, compared to the existing methodology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.757-763
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• 2019

Youtube has become so popular that it is called the age of YouTube. As the number of users and contents increase, the choice of information increases. However, it is difficult to select information that meets the needs of users. YouTube provides recommendations based on their watch list. Therefore, in this study, we want to analyze the channel of user's subject in various angles and provide the proposed scheme based on the crawled channels, measurement of the perception of channels and channel videos through quantitative data and hidden qualitative data analysis. Based on the above two data analysis, it is possible to know the recognition of the channel and the recognition of the channel video, thereby providing a ranking of the channels that deal with the topic. Finally, as a case study, we recommend English learning channels to users based on numerical data statistics and emotional analysis results to maximize flipped learning effect regardless of time and space.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.2
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• pp.47-53
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• 2007

Laminar heat transfer experiments were conducted in flat extruded aluminum tubes. Three different flat tubes-two with smooth inner channel, one with micro-finned inner channel-were tested. Smooth tube data were in reasonable agreement with the predictions by simplified theoretical models. The heat transfer coefficients of the micro-fin tube were significantly smaller than those of the smooth tube. The reason was attributed to the decelerating flow in the inter-fin region. Heat transfer correlations were developed from the data.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.623-631
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• 2003

A large scale hydrological laboratory model tests for the geotextile tube were conducted to investigate the stability of geotextile tube and the capability of breakwater with variations of significant wave height, percentage of soil filling, and the water level above geotextile tube. The sliding displacement of geotextile tube is measured to check the stability of geotextile tube for given the various significant wane heights. The marked mash was laid out at the bottom of water channel to measure the displacement of geotextile tube. The bench mark was furnished in the upper part of water channel and the initial location was marked every 10cm interval to measure the displacement of geotextile tube. The wane transmit ratios are analyzed with the variations of soil filling of tube and of the top crown height wave above the geotextile tube in order to study the performance of brekwater before and after the installation of geotextile tube.

• Nuclear Engineering and Technology
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• v.37 no.5
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• pp.479-490
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• 2005

The thermalhydraulic performance of a CANDU-6 reactor loaded with various CANFLEX fuel bundles is evaluated by the NUCIRC code, which is incorporated with recent models of pressure drop and critical heat flux (CHF) predictions based on high-pressure steam-water tests for the CANFLEX bundle as well as a 37-element bundle. The distributions of channel flow rate, channel exit quality, critical channel power (CCP), and critical power ratio (CPR) for the CANFLEX bundles (with natural or recycled uranium fuel) in the CANDU-6 reactor fuel channel are calculated by the code. The effects of axial and radial heat flux on CCP are evaluated by assuming that the recycled uranium fuel (CANFLEX-RU) has the same geometric data as the natural uranium fuel bundle (CANFLEX-NU), but a different power distribution due to different fuel composition and refueling scheme. In addition, the effects of pressure tube creep and bearing-pad height are examined by comparing various results of uncrept, and $3.3\%\;and\;5.1\%$ crept channels loaded with CANFLEX bundles with 1.4 mm or 1.7 mm high bearing-pads with those of the 37-element bundle. The distributions of the channel flow rate and CCP for the CANFLEX-NU or -RU bundle show a typical trend for a CANDU-6 reactor channel, and the CPRs are maintained above at least 1.444 (NU) or 1.455 (RU) in the uncrept channel. The enhanced CHF of the CANFLEX bundle (particularly with 1.7mm height bearing-pads) produces a higher thermal margin and considerably less sensitivity to CCP reduction due to the pressure tube creep than the 37-element bundle. The CCP enhancement due to the raised bearing-pads is estimated to be about $3\%\~5\%$ for the CANFLEX-NU and $2\%\~6\%$ for the CANFLEX-RU bundle, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1195-1202
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• 2004

In this paper an experimental study was investigated for two-phase flow distribution in compact heat exchanger header. A test section was consisted of the horizontal bottom dividing header($\phi$: 5 mm, L: 80 mm) and 10 upward circular mini channels ($\phi$: 1.5 mm, L: 850 mm) using an acrylic tube. Three different types of tube intrusion depth were tested for the mass flux and inlet mass quality ranges of 50 - 200 kg/$m^2$s and 0.1 - 0.3, respectively. Air and water were used as the test fluids. The distribution of vapor and liquid is obtained by measurement of the total mass flow rate and the calculation of the quality. Two-phase flow pattern was observed, and pressure drop of each channel was measured. By adjusting the intrusion depth of each channel an uniform liquid flow distribution through the each channel was able to solve the mal-distribution problem.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.181-203
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• 2023

YouTube exhibits a hybrid personality, incorporating traits of both over-the-top (OTT) and personal broadcasting platforms. However, limited research has investigated these hybrid characteristics, particularly in the context of paid YouTube channel memberships. Therefore, building upon consumption value theory and prior literature, this study examines the influence of consumption value factors associated with paid YouTube channel memberships on usage satisfaction and continuance intention. Specifically, the study identifies four perceived consumption value factors (functional, social, emotional, and epistemic values) within the paid YouTube channel membership context and assesses their impact on usage satisfaction and continuance intention. Additionally, the study explores the moderating role of conditional value (the experience of watching live streams on paid YouTube channels) in these relationships. Data was collected via an online survey from Korean adults who subscribed to multiple paid YouTube channel memberships, resulting in 274 responses. The proposed hypotheses were tested using structural equation modeling (SEM). The SEM results indicate that all four consumption value factors significantly influence usage satisfaction, with usage satisfaction in turn positively affecting continuance intention. Furthermore, the study reveals that conditional value moderates the relationships between functional/emotional values and usage satisfaction, as well as between usage satisfaction and continuance intention. This study is the first to focus on YouTube channel paid memberships, which encompass characteristics from both OTT and personal broadcasting platforms. It is anticipated that this research will offer insights to personal broadcasters and stakeholders regarding the motivational factors that impact user satisfaction and encourage subscriptions to channel memberships.

• Journal of Science Education
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• v.45 no.1
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• pp.118-128
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• 2021

In this study, as the viewing characteristics of users of YouTube video content related to science education, 'Inflow and Access' is analyzed to find out the interaction between learners and the system, and 'Reaction and Subscription' to find out the interaction between learners and contents. To this end, the YouTube channel "Elementary Science TV," was selected as the subject of research. The channel is mainly focused on the contents of elementary science textbooks, STEAM, and gifted education. The channel's data of YouTube studio was analyzed. The following results were obtained through data analysis: first, as a result of 'Inflow and Access' analysis, YouTube video content related to science education was most often introduced through external links, and the access device was mainly a computer. Second, as a result of the analysis of 'Reaction and Subscription,' 'like' and commenting performed as a reaction to the video were less than 1% of the number of views. Most users watch without a subscription, and watch for longer when using self-directed. Although this study was analyzed through a limited channel called 'Elementary Science TV,' we were able to discover a little about the users' viewing characteristics of YouTube video contents related to science education. In the future, it is expected that it can be used as a basic material for creating videos related to science education for remote classes, establishing a science education video platform.