• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.74-85
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• 2019

This Study explores the reason why the social media like Cyworld, Iloveschool in Korea in the viewpoint if the layered model by interview. As a result the success factor in the viewpoint of layered model, user used social media for fulfilling the need for linking with other users and the social media offers the customized contents to user. Finally the social media dominated the market in advance. Facebook and Kakao talk are good examples of successful media. The failure factors are to care less about what other users want, to limit the expand of platform and not to copy with the change of the media environment. Iloveschool, Cyworld and Twitter are the examples of failure social media in Korean society. This study highlights the importance of the sensitivity of the change of environment. The expert mentioned the importance of 4th industrial revolution technology like AI, Big data and expected that new technology will emerge and the service will be developed by the change of user's taste.

• Knowledge Management Research
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• v.19 no.4
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• pp.39-58
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• 2018

This study explores the effects of business consulting on the business performance of firms by using a unique survey for various industry sectors in Korea. We attempt to build a consulting model that shows the structural relationship between consulting factors and consulting performance. Moreover, through the consulting model, we conduct the analysis of elasticity of consulting factors and the group analysis based on firm age. First, the findings show that all consulting factor has a positive impact on the consulting performance, but in the results of factor elasticity, they have a somewhat different impact. Second, while the support of CEOs is relatively more elastic than other consulting factors with respect to the completion of consulting projects, the institutional condition for consulting is relatively more elastic than other factors with respect to the contribution to business performance. Third, since the high-firm age group has a greater capacity to absorb and utilize external knowledge and resource, the consultant competency and institutional conditions have a more impact on the consulting performance than the low-firm age group. On the other hand, in the low-firm age group, the result indicates that the support of CEOs has a more impact in the consulting performance than the high-firm age group. According to the total effect, the support of CEOs in the entire model has the highest impact on the consulting performance. Thus, it is probably difficult to achieve the improvement of business performance through consulting as well as the successful consulting projects without the CEOs' commitment and awareness about the consulting projects.

• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.325-333
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• 2019

This study was conducted to investigate the factors affecting satisfaction and dissatisfaction of e-learning learner students using Kano model and Timko's customer satisfaction coefficient. The results of the analysis showed that firstly, the students are highly satisfied when it is convenient to learn visually and audibly, when the students can ask questions at any time, and when the professor was interested in the students. Second, the rational criteria and accurate evaluation of grades and assignments were confirmed as factors that should be satisfied. Third, unlike the results of the basic study that the students use e-learning due to the convenience of learning time and learning space and the ease of learning process, it is no longer an attractive factor to use e-learning. The results of this study suggest that it is possible to present effective directions for the development of e-learning education and strategic application of each factor classified by the two-dimensional recognition method.

• Tribology and Lubricants
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• v.35 no.3
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• pp.158-168
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• 2019

This paper presents the investigation of two types of rotordynamic modeling issues for 2.2 kW-class, rated speed of 1,800 rpm, squirrel-cage type induction motors. These issues include the lamination structure of rotor cores, and the radial clearance of ball bearings that support the shaft of the motor. Firstly, we focus on identifying the effects of rotor core lamination on the rotordynamic analysis via a 2D prediction model. The influence of lamination is considered as the change in the elastic modulus of the rotor core, which is determined by a modification factor ranging from 0 to 1.0. The analysis results show that the unbalanced response of the rotor-bearing system significantly varies depending on the value of the modification factor. Through modal testing of the system, the modification factor of 0.079 is proven to be appropriate to consider the effects of lamination. Next, we investigate the influence of ball bearing clearance on the rotordynamic analysis by establishing a bearing analysis model based on Hertz's contact theory. The analysis results indicate that negative clearance greatly changes the bearing static behavior. Rotordynamic analysis using predicted bearing stiffness with various clearances from -0.005 mm to 0.010 mm reveals that variations in clearance result in a slight difference in the displacement of the system up to 18.18. Thus, considering lamination in rotordynamic analysis is necessary as it can cause serious analysis errors in unbalanced response. However, considering the effect of the bearing clearance is optional because of its relatively weak impact.

• Research in Community and Public Health Nursing
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• v.31 no.4
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• pp.436-446
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• 2020

Purpose: This study aims to explore the association between unemployment and depression in people from different age groups ranging from 18 to 65 years old. Methods: This study used a cross-sectional design. We performed bivariate analysis and multivariable logistic regression on the 2010 Behavioral Risk Factor Surveillance System (BRFSS) data from 12 states in the United States. Results: On a sample comprised of n=53,406 individuals, of whom 2,546 (7.8%) were identified as being depressed and 3,448 (10.6%) as unemployed, we found that individuals aged 61~65 years have a lower depression risk compared to those aged 18-25 after adjusting for other variables including employment status. However, people from 61~65 have higher increased risk of depression when unemployed compared to other age groups in all three models tested (3.95 times higher in unemployed people in model 1, and 2.81 times higher in model 2 and model 3). Conclusion: Our findings indicate that there may need to be more focus on older adults who are unemployed, with associated support services for their mental health. The results of our study indicate that although older adults are less likely to be unemployed, there are more likely to experience depression if they are unemployed (once other confounding factors are taken into account) than younger adults. Policies and interventions can be developed to address not only the physical difficulties but also the mental challenges with which older adults can be at risk facing in case of unemployment.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.125-134
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• 2021

With the rapid development of the film industry, the number of films is significantly increasing and movie recommendation system can help user to predict the preferences of users based on their past behavior or feedback. This paper proposes a movie recommendation system based on the latent factor model with the adjustment of mean and bias in rating. Singular value decomposition is used to decompose the rating matrix and stochastic gradient descent is used to optimize the parameters for least-square loss function. And root mean square error is used to evaluate the performance of the proposed system. We implement the proposed system with Surprise package. The simulation results shows that root mean square error is 0.671 and the proposed system has good performance compared to other papers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.10-16
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• 2021

This paper proposes a model that considers the parity-time symmetric structure as a state detection circuit for sensor applications using a stretchable inductor. In particular, to obtain a more practical computer simulation result, the stretchable inductor model was applied to this study model by referring to previously reported experimental results. The resistance component and phase component were controlled through the negative differential resistance circuit used in this study. In addition, the imbalance of the circuit caused by a change in the characteristics of the stretchable inductor could be compensated for using a negative differential resistance circuit. In particular, an analysis of the frequency characteristics of the sensor driving circuit of the parity-time symmetric structure proposed in this study confirmed that the Q-factor could be increased up to 20 times compared to the conventional resonant circuit.

• Smart Structures and Systems
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• v.29 no.1
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• pp.41-51
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• 2022

Cables are critical components of cable-stayed bridges. A structural health monitoring system provides real-time cable tension recording for cable health monitoring. However, the measurement data involve multiple sources of variability, i.e., varying environmental and operational factors, which increase the complexity of cable condition monitoring. In this study, a one-class classification method is developed for cable condition assessment using Bayesian factor analysis (FA). The single-peaked vehicle-induced cable tension is assumed to be relevant to vehicle positions and weights. The Bayesian FA is adopted to establish the correlation model between cable tensions and vehicles. Vehicle weights are assumed to be latent variables and the influences of different transverse positions are quantified by coefficient parameters. The Bayesian theorem is employed to estimate the parameters and variables automatically, and the damage index is defined on the basis of the well-trained model. The proposed method is applied to one cable-stayed bridge for cable damage detection. Significant deviations of the damage indices of Cable SJS11 were observed, indicating a damaged condition in 2011. This study develops a novel method to evaluate the health condition of individual cable using the FA in the Bayesian framework. Only vehicle-induced cable tensions are used and there is no need to monitor the vehicles. The entire process, including the data pre-processing, model training and damage index calculation of one cable, takes only 35 s, which is highly efficient.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.23.1-23.16
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• 2023

Background: Irritable bowel syndrome (IBS) is a functional bowel disorder (FBD). Objectives: To assess the therapeutic effects of paeoniflorin (PF) on IBS in rats. Method: Sixty male Sprague-Dawley rats were randomly divided into normal, model, positive drug, low-dose PF, medium-dose PF and high-dose PF groups (n = 10). After gavage for 2 consecutive weeks, the effect of PF on abdominal pain symptoms was assessed based on the abdominal withdrawal reflex (AWR) score, fecal water content and pathological changes in colon tissues. D-lactate, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay, and phosphorylated nuclear factor kappa B (p-NF-κB) p65 was detected by Western blotting. The abundance and diversity changes of intestinal flora were explored using 16S ribosomal RNA sequencing. Result: In PF groups, the mucosal morphology of colon tissues was intact, and the glands were arranged neatly and structured clearly, without obvious inflammatory cell infiltration. Compared with the model group, PF groups had significantly elevated pain threshold, and mRNA and protein levels of zonula occludens-1 (ZO-1) and occludin, decreased AWR score at 20 mmHg pressure, fecal water content, mRNA levels of IL-1β, TGF-β, and TNF-α, protein level of p-NF-κB p65 and level of serum D-lactate, and reduced levels of serum IL-1β, TGF-β, and TNF-α (p < 0.05, p < 0.01). PF groups had higher abundance of Lactobacillus, Akkermansia, Alistipes, and Bacteroides, but lower abundance of Desulfovibrio, Parasutterella, and Enterococcus than those of the model group. Conclusions: PF exerts therapeutic effects on IBS in rats probably by regulating the intestinal flora, and then up-regulating the expressions of ZO-1 and occludin in colon tissue while down-regulating the levels of IL-1β, TGF-β, TNF-α, D-lactate and p-NF-κB p65.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.4
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• pp.143-156
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• 2023

The domestic threat information sharing system to deal with various security threats in the rapidly changing cyber environment needs to be improved. In this study, to solve these problems and promote the activation of threat information sharing, we derive a research model based on the value-based containment model (VAM) for vital factors in information sharing. After conducting a Ricardian 5-point survey on a total of 204 individuals, the statistical results of the first 151 individuals were analyzed using SPSS and AMOS, and the statistical results of the second 204 individuals were analyzed using R-Studio. As a result, perceivability was found to have a significant impact as a core factor in the activation of cyber threat information sharing (β=0.405, p<0.01), and the hindrance factor was analyzed as innovation resistance (β=-0.152, p<0.01). Microscopically, the obtained results can be applied to factor analysis for activating information sharing of cyber threats by companies in the future, and macroscopically, they can contribute to the foundational development of a national cyber threat response system.