• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.439-450
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• 2019

Let R be a ring with unity. Given modules $M_R$ and $_RN$, $M_R$ is said to be absolutely $_RN$-pure if $M{\otimes}N{\rightarrow}L{\otimes}N$ is a monomorphism for every extension $L_R$ of $M_R$. For a module $M_R$, the subpurity domain of $M_R$ is defined to be the collection of all modules $_RN$ such that $M_R$ is absolutely $_RN$-pure. Clearly $M_R$ is absolutely $_RF$-pure for every flat module $_RF$, and that $M_R$ is FP-injective if the subpurity domain of M is the entire class of left modules. As an opposite of FP-injective modules, $M_R$ is said to be a test for flatness by subpurity (or t.f.b.s. for short) if its subpurity domain is as small as possible, namely, consisting of exactly the flat left modules. Every ring has a right t.f.b.s. module. $R_R$ is t.f.b.s. and every finitely generated right ideal is finitely presented if and only if R is right semihereditary. A domain R is $Pr{\ddot{u}}fer$ if and only if R is t.f.b.s. The rings whose simple right modules are t.f.b.s. or injective are completely characterized. Some necessary conditions for the rings whose right modules are t.f.b.s. or injective are obtained.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.235-241
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• 2019

The purpose of this study is to investigate the characteristics of advertising section of the daily newspaper through content analysis. From April 2015 to March 2017, a total of 1,927 advertisements were analyzed by the newspaper ethics committee, and the following results were obtained. Firstly, most types of features (advertising) received more attention than warnings. Secondly, we can confirm that the amount of advertisement in section (featured) of major daily newspapers is gradually increasing, and section advertisement is appeared in major business districts. Third, there were many violations in the practice guidelines of the newspaper code of ethics as the media's responsibility and press coverage. Finally, in the case of certain companies and products, if you do not follow the principles of publication for profit and publicity, you may need to make your own efforts to protect the credibility and fairness of newspapers, and more autonomous guidelines.

• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.146-152
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• 2019

This study discussed implications of the increase of single person households (SH) for high-tech industries especially focusing on artificial intelligence (AI) adopted products, based on critically reviewing the past researches on their characteristics including consumption trends; the improvement of AI technology; and its market potentiality in various industries. According to the results, SH spent more time with others like friends and neighbors more than couples. Younger people increasingly chose to live alone by their own free will for achieving their goals. 'Living alone' or 'going solo' is not thought negatively any more, but as a new market power in the future. Considering their value oriented consumption behaviors based on spirit of independence and individualism, they will need high-tech products more like AI adopted products than others because of their advantages for the value of single life. Thus, the rapid progress of AI technology is predicted to bring them satisfaction of their wants and it is suggested to prepare for the market segmentation of SH as AI end-users.

• BMB Reports
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• v.54 no.10
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• pp.497-504
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• 2021

EGR1 (early growth response 1) is dysregulated in many cancers and exhibits both tumor suppressor and promoter activities, making it an appealing target for cancer therapy. Here, we used a systematic multi-omics analysis to review the expression of EGR1 and its role in regulating clinical outcomes in breast cancer (BC). EGR1 expression, its promoter methylation, and protein expression pattern were assessed using various publicly available tools. COSMIC-based somatic mutations and cBioPortal-based copy number alterations were analyzed, and the prognostic roles of EGR1 in BC were determined using Prognoscan and Kaplan-Meier Plotter. We also used bc-GenEx-Miner to investigate the EGR1 co-expression profile. EGR1 was more often downregulated in BC tissues than in normal breast tissue, and its knockdown was positively correlated with poor survival. Low EGR1 expression levels were also associated with increased risk of ER+, PR+, and HER2- BCs. High positive correlations were observed among EGR1, DUSP1, FOS, FOSB, CYR61, and JUN mRNA expression in BC tissue. This systematic review suggested that EGR1 expression may serve as a prognostic marker for BC patients and that clinicopathological parameters influence its prognostic utility. In addition to EGR1, DUSP1, FOS, FOSB, CYR61, and JUN can jointly be considered prognostic indicators for BC.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.480-493
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• 2021

In this paper, we attempt to empirically explain the process by which fandom performs social participation using digital media. To do this, we utilize the concept of identification and the Situational Theory of Publics in a theoretical framework, and study ARMY, BTS fandom. We confirmed a positive association between communication behavior and social participation, and verified a mediating effect of the identification as well. Interestingly, horizontal identification, a fan-to-star friendly relationship, had a greater effect on moving toward social participation than did vertical identification, a fan's blind worship of a star. This study has significance in that it has figured out the relationship of personal feelings to public participation by mobilizing achievements in various research fields.

• PNF and Movement
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• v.18 no.3
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• pp.343-350
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• 2020

Purpose: The purpose of this study was to determine how a shoulder complex stabilization exercise affects ball control and ball speed in elementary school baseball players with an instable scapula. Methods: The subjects of the study were 16 baseball players attending S elementary school in Kwangju Metropolitan City. A shoulder complex stabilization exercise was conducted three times per week for one hour for four weeks. Then, the participants were divided into a scapular instability group or stability group based on their lateral scapular slide test scores. The measurement tool was measured using the target, the ball speed tester (PR1000-BC). All inspections were measured before and after the mediation period to examine the change in the subjects according to the mediation period. Results: As a result of measuring ball control, there was a statistically significant difference in the variation over time (p < 0.05), and there was no statistically significant difference in the interaction between time and group (p > 0.05). As a result of the test of effectiveness between subjects, there was no statistically significant difference found among the groups (p > 0.05). In terms of ball speed, there was no statistically significant difference found in the variation over time (p > 0.05) as well as in the interaction between time and group (p > 0.05). In terms of the effectiveness between subjects, there was no statistically significant difference found among the groups (p > 0.05). Conclusion: It was found that the shoulder complex stabilization exercise could improve ball control for elementary school baseball players. It is believed that this will help prevent and solve possible sport damages experienced during training or competitions, thereby helping athletes use training methods to improve their exercise capacity and continue their careers.

• Advances in nano research
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• v.10 no.3
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• pp.221-234
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• 2021

During the previous few years, phenomenon of bioconvection along with the use of nanoparticles showed large number of applications in technological and industrial field. This paper analyzed the bioconvection phenomenon in magnetohydrodynamic boundary layer flow of a Powell-Eyring nanoliquid past a stretchable cylinder with Cattaneo-Christov heat flux. In addition, the impacts of chemical reaction and heat generation/absorption parameter are considered. By the use of appropriate transformation, the governing PDEs (nonlinear) have been transformed and formulated into nonlinear ODEs. The resulting nonlinear ODEs subjected to relevant boundary conditions are solved analytically through homotopy analysis method which is programmed in Mathematica software. Graphical and numerical results versus physical quantities like velocity, temperature, concentration and motile microorganism are investigated under the impact of physical parameters. It is noted that velocity profile enhances as the curvature parameter A and Eyring-Powell fluid parameter M increases but a decline manner for large values of buoyancy ratio parameter Nr and bio-convection Rayleigh number Rb. In the presence of Prandtl number Pr, Eyring-Powell fluid parameter M and heat absorption parameter ��, temperature profile decreases. Nano particle concentration profile increases for increasing values of magnetic parameter Ha and thermophoresis parameter Nt. The motile density profile has revealed a decrement pattern for higher values of bio-convection Lewis number Lb and bio-convection peclet number Pe. This study may find uses in bio-nano coolant systems, advance nanomechanical bio-convection energy conversion equipment's, etc.

• Journal of IKEEE
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• v.24 no.4
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• pp.1104-1108
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• 2020

This paper propose a variable proportional resonant feedforward algorithm for reducing the speed ripple of a three-phase permanent magnet synchronous motor. In general, the torque ripples can be generated by electrical pulsation due to current measurement errors and dead time and mechanical pulsation because of rotor eccentricity and eccentric load. These torque pulsations can cause speed pulsations of the motor and degrade the operating performance of the motor drive system. Therefore, in this paper, the factors of the speed ripple is analyzed and an algorithm to reduce the speed ripple is proposed. The proposed algorithm applied a variable proportional resonant controller in order to reduce the specific operating frequency included in the speed pulsation, and utilized a feedforward compensation controller structure to perform the compensation operation. The proposed algorithm is verified through various experiments.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.223-229
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• 2021

This study starts with the premise that many problematic situations in modern society can seriously damage personal feelings and that this phenomenon can create anxiety in individuals and society. In order to address such anxiety in individuals and society, we would like to propose measures to heal emotions. Accordingly, 270 research trends related to emotions studied from 2005 to 2020 will be analyzed to establish the direction of future research on emotion healing. As a result of analyzing the trends of healing papers, active healing studies have been conducted since 2010, but reading and writing healing through specific academic societies has been the main focus. Theoretical research accounted for a large portion, and emotional research was steadily conducted. Although healing methods are expanding to various topics, they have not been commercialized as specific methods. As a result, we hope that concrete research to heal individual emotions will be expanded and measures to implement a stable future society will be proposed.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.163-171
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• 2021

This study aimed to investigate the main characteristics of the COVID-19 vaccine-related videos spread on YouTube and differences in user responses in the infodemic situation caused by COVID-19. As a result of content analysis of 579 videos related to the COVID-19 vaccine, it was found that all of the false information was written by individual channels. Institutions, organizations, media companies, and government channels reported spread of false information as well as fact-oriented reporting. The progressive channel had a high percentage of positive sentiment in favor of vaccination, and the conservative channel had a high percentage of negative emotion against vaccination. After the vaccination started, the number of videos on government channels increased, and it was found that the number of videos with positive emotions increased. Results of regression analysis of video characteristics that affect the number of likes indicated that personal expert videos and videos from progressive channels received more likes. Combining the research results, we propose a plan to promote government policies regarding the COVID-19 vaccine using social media.