• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.21-33
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• 2022

Recently, the recommender system has been widely used in various fields such as movies, music, online shopping, and social media, and in the meantime, the recommender model has been developed from correlation analysis through the Apriori model, which can be said to be the first-generation model in the recommender system field. In 2005, many models have been proposed, including deep learning-based models, which are receiving a lot of attention within the recommender model. The recommender model can be classified into a collaborative filtering method, a content-based method, and a hybrid method that uses these two methods integrally. However, these basic methods are gradually losing their status as methodologies in the field as they fail to adapt to internal and external changing factors such as the rapidly changing user-item interaction and the development of big data. On the other hand, the importance of deep learning methodologies in recommender systems is increasing because of its advantages such as nonlinear transformation, representation learning, sequence modeling, and flexibility. In this paper, among deep learning methodologies, RNN, CNN, and GAN-based models suitable for sequential modeling that can accurately and flexibly analyze user-item interactions are classified, compared, and analyzed.

• Journal of the Korean Ceramic Society
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• v.46 no.3
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• pp.229-233
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• 2009

This study has focused on manufacturing technique of powder injection molding of watch case made from zirconia powder. A series of computer simulation process was applied to prediction of the flow pattern in the inside of the mould to clarifying the change of sintering shrinkage depended on flow direction. The material properties of melted feedstock inclusive of the PVT graph and thermal viscosity flowage properties were measured for obtaining the input data in computer simulation. Also, molding experiment was conducted and the results of experiment showed that good agreement with simulation results for flow pattern and weld line location. On the other hand, gravity and inertia effect have an influence on velocity of melt front because of high density of ceramic powder particles in powder injection molding against the polymer injection molding process. In the experiment, the position of melt front was compared with upper gate and lower gate position. The gravity and inertia effect could be confirmed in the experimental results.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.505-516
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• 2020

The purpose of the research is to identify antecedents of mobile wallet continuance intention in Vietnam. A self-administered questionnaire was distributed to collect data from a total of 276 respondents. Partial least squares structural equation modeling was employed for analyzing the data. Five mobile wallet features - mobile application quality, mobile wallet familiarity, situational normality, payment security, and feedback mechanism - are introduced as fundamental elements, which influence customer' continuance intention to use mobile wallet in Vietnam. The results indicate that mobile quality application and familiarity can significantly influence perceived ease-of-use (PEOU) and perceived usefulness (PU), but situational normality has an impact only on PEOU. PEOU and PU are positively related to satisfaction. On the other hand, payment security and feedback mechanism affect positively customer' trust. As a result, the positive effects that satisfaction and trust have on electronic wallet continuance intention are confirmed. The findings can be used to advise mobile wallet providers to improve their platform design and services to retain users. As a theoretical contribution, this study combines the Technology Acceptance Model, Unified Theory of Acceptance and Use of Technology to investigate the key determinants on continuance intention in the context of electronic wallet in Vietnam.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.1189-1200
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• 2021

This study examines the role of perceived enjoyment, self-efficacy, and subjective norms as determinants of behavioral intention to use the OVO application. This study's target population is the users of the OVO application who have used it as an electronic transaction. This study's population was the OVO application users as an electronic transaction tool in Jember Regency. Samples were randomly selected at the time of the survey with specific criteria. The survey location is determined at the Plaza because it is a shopping center that mostly has payments at OVO partner merchants. The model empirically tested using data gathered from 150 respondents of OVO users. The research model was tested by using the structural equation modeling (SEM) approach. The results showed that all constructs in the original TAM model were statistically significant. Subjective norm has a positive effect on perceived usefulness, and perceived enjoyment positively affects perceived ease of use of OVO applications. On the other hand, applications' self-efficacy does not affect the perceived ease of using OVO applications for electronic transactions. This condition shows that subjective norms are dominant external individual perspectives compared to self-efficacy, which are personal internal characteristics in determining the behavioral intention of using OVO applications in electronic transactions.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.885-894
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• 2021

This study aims to analyze the effect of the ratio of profitability and solvability (leverage) on the variable stock price, which is mediated (intervening) by the variable dividend policy. Using the financial reports of manufacturing companies in the consumer goods sector, we take profitability data (ROA, ROE, GPM, and NPM), solvability data (DAR, LTDER, and DER), dividend policy (DPR), and stock price (closing price) from 24 companies, which were selected as samples, from 2011 to 2018. Data was analyzed using the Structural Equation Modeling (SEM) method. The results show that profitability, solvability, and dividend policy affect changes in stock prices, respectively. On the other hand, profitability and solvability do not affect dividend policy. The indirect relationship (intervening) is assessed using a single test, resulting in a dividend policy that can intervene in the relationship between profitability and stock prices but cannot mediate the relationship between solvability and stock prices. The implication of this research is to provide knowledge to investors about the importance of knowing the company's financial performance. Companies with good financial performance will easily develop because there are sufficient funds for company operations. By analyzing financial ratios, investors can get signals to decide whether to invest in the company they want.

• Journal of Information Technology Services
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• v.21 no.2
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• pp.43-59
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• 2022

This study investigates an association among Facebook users' upward comparison (e.g., envy), social support (e.g., favorable comments and like), and life satisfaction, putting their self-esteem as a mediating variable. For this analysis, 1,332 female and male Facebook users in Seoul and other four cities in South Korea were surveyed. Structural equation modeling including confirmative factor analysis were employed as quantitative analysis methods. Results show that Facebook users' upward comparison with other users and social support significantly impact their satisfaction mediated by their self-esteem. Specifically, when users feel envious of other users, this emotion lowers their self-esteem, and subsequently, the self-esteem reduces their satisfaction. On the other hand, sufficient social support for users positively affects their self-esteem, which leads to the increase of their satisfaction. The present study is differentiated from previous studies in that it focuses on Facebook users' emotional changes in the process of sharing massive amounts of posts and finds a stepwise relationship among their feelings, including self-esteem as a mediating variable. Additionally, this study is the first to verify a situation when Facebook users' envy of other users' posts affects the decline in their satisfaction through the mediation of their self-esteem.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.1
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• pp.93-103
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• 2022

The main purpose of this study was to gauge the patient satisfaction index and subsequently discuss the Importance-Performance (IP) matrix analysis of the inpatient services in the context of the private hospital setting. The Malaysian Customer Satisfaction Index Model was employed as the theoretical framework for the above purposes. This study involving 242 patients in Malaysian's private healthcare sector used a Web-based survey as the main method of data collection. Partial least square structural equation modeling (PLS-SEM) was utilized for data analysis. Using Fornell et al. (1996)'s formula, the resulting patient satisfaction index was slightly lower than the "very satisfied" category, the target level required for positioning as one of the world's premier medical tourism players. The IP matrix showed that medical quality is the main competitive advantage of the private hospitals that can propel their growth in the global healthcare marketplace. The results also indicate that outcome quality, patient rights, and privacy, and service quality are the three quality domains that need to be prioritized for further improvement. On the other hand, the servicescape quality domain needs to be strategized as the unique selling proposition as the performance of the private hospitals in this regard is already extremely good.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.105-113
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• 2024

The natural gas dehydration process plays a central role in liquefying LNG. This study proposes two natural gas dehydration process systems applicable to liquefied natural gas (LNG) liquefaction plants, and compares and analyzes energy optimization measures through simulation. The fuel gas from feed stream (FFF) case, which requires additional equipment for gas circulation, disadvantages are design capacity and increased energy. On the other hand, the end flash gas (EFG) case has advantages such as low initial investment costs and no need for compressors, but has downsides such as increased power energy and the use of gas with different components. According to the process simulation results, the required energy is 33.22 MW for the FFF case and 32.86 MW for the EFG case, confirming 1.1% energy savings per unit time in the EFG case. Therefore, in terms of design pressure, capacity, device configuration, and required energy, the EFG case is relatively advantageous. However, further research is needed on the impact of changes in the composition of regenerated gas on the liquefaction process and the fuel gas system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.2
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• pp.7-12
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• 2014

Government has recently restricted heating and cooling set temperatures for the commercial and public buildings due to increasing national energy consumption. The goal of this paper is to visualize a future two way indoor set temperature control impact on building energy consumption by using TRNSYS simulation modeling. The building was modelled based on the twin test cell with the same dimension. Air source ground coupled heat pump performance data has been used for modeling by TRNSYS 17. Daejeon weather data has been used from Korea Solar Energy Society. The heating set temperature in the reference room is $24^{\circ}C$ as well as the target room set temperature are $23^{\circ}C$, $22^{\circ}C$, $21^{\circ}C$ and $20^{\circ}C$. The cooling set temperature of the reference room is also $24^{\circ}C$ as well as the target room set temperature of $25^{\circ}C$, $26^{\circ}C$, $27^{\circ}C$ and $28^{\circ}C$. For the air source heat pump system, heating season energy consumption is $35.52kWh/m^2y$ in the reference room. But the heating energy consumption in the target room is reduced to 7.5% whenever the set temperature decreased every $1^{\circ}C$. The cooling energy consumption in the reference room is $4.57kWh/m^2y$. On the other hand, the energy consumption in the target room is reduced to 22% whenever the set temperature increased every $1^{\circ}C$ by two way controller. For the geothermal heat pump system, heating energy consumption in the reference room is reduced to 20.7%. The target room heating energy consumption is reduced to 32.6% when the set temperature is $22^{\circ}C$. The energy consumption in the target room is reduced to 59.5% when the set temperature is $26^{\circ}C$.

• Journal of Korean Library and Information Science Society
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• v.53 no.3
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• pp.455-477
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• 2022

This study aimed to compare and analyze librarian teacher evaluation index from evaluation of teachers' competency development with the the topics of information utilization education. To this end, LDA topic modeling was conducted by collecting papers related to information utilization education published in four major journals in the field of literature and information from 1995 to May 2022. As a result of topic modeling, it can be seen that information utilization education (T10) was the most actively discussed at 12.0% of the 20 topics, followed by library utilization classes (T2) 10.4% and user service (T3) 8.8%.On the other hand, 3.3% of reading discussion (T7), 2.9% of reading education (T19), 2.1% of manpower management (T13), and 2.1% of librarian teacher job satisfaction (T17) showed the lowest distributions 3.3%, 2.9%, 2.1%, and 2.1%, respectively. In addition, although librarian teacher's class model development (T1) and curriculum development (T20) are essential processes for collaborative classes and information utilization education, they were not reflected in the current teacher competency development evaluation index. Therefore, this study proposed that 'instructional model and curriculum development' indicator should be added on 'training and support classes' factors in the Librarian Teacher Evaluation Index in Teachers' Competency Development Evaluation for further evaluation.