• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.474-481
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• 2018

The purpose of this study was to examine the mediating effects of maternal family experience on the relationship between mothers' tendency to addicted to smartphones and the social competence of young children. The subjects of this study were 481 mothers who delivered infants to a kindergarten or daycare center in Jeju area After conducting the questionnaire, the results of the responses were analyzed. To analyze the collected data, structural equations were implemented using SPSS Statistic 18.0 program. The results of this study are summarized as follows. First, the correlational analysis showed that the tendency of the addiction of smartphone and the social ability of the infant showed a significant correlation with the mother's family experience. Second, in the relationship between the mother's smartphone tendency and the social competence of the infant, The research model and the competition model were set up to examine the mediating effect and the competition model was found to be more appropriate. As a result, it can be seen that mother's original family experience is partly mediated in relation to mother's tendency to add to smartphone and social competence of infant. Based on these results, the implications of this study and suggestions for subsequent research were discussed.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.206-225
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• 2016

This study analyzes the effect of authentic leadership on organizational climate, organizational citizenship behavior, and job performance to suggest the implications behind the growing importance of authentic leadership. In particular, this study substantiates existing arguments that organizational climate moderates the tension between leaders and employees by investigating the mediating effects of organizational climate on the relationship between authentic leadership and job performance. A survey was conducted on employees of various business areas in Korea, and 444 responses were used in statistical analysis which was performed using SPSS/WIN 24.0 and STATA 14.0 statistics package and verified using structural equations. The analysis results showed that 1) authentic leadership has positive effects on organizational climate, organizational citizenship behavior, job performance; 2) organizational climate has positive effects on organizational citizenship behavior and job performance; 3) organizational citizenship behavior has a positive effect on job performance; and 4) organizational climate performs a mediating role in the relationships among authentic leadership, organizational citizenship behavior, and job performance. By including organization climate's mediating effect as a factor in the research on authentic leadership, this study presents a new perspective for future studies on leadership.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.259-267
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• 2020

Teaching and learning is based on communication between instructors and learners. In addition to instructor's verbal communication in the classrooms, non-verbal communication plays an important role. There is growing concerned about instructor's non-verbal communication affecting the learning process and learning outcomes. Based on the literature research student's emotional presence and rapport were used variables of learning process, and learning satisfaction was used as a variable of learning outcome to see the relationship of instructor's non-verbal communication. Data was collected from 378 students at A university in Gyeonggi-do and K university in Daejeon. The data was analyzed through structural equations modeling. As a result of the study, instructor's non-verbal communication had a positive impact on emotional presence and rapport. Emotional presence had a significant influence on rapport and learning satisfaction positively, and rapport had a positive effect on learning satisfaction. Instructors should be able to recognize the role of non-verbal communication in the classes as well as be able to use it appropriately. This study could be used as basic data onto the use of non-verbal communication in university classrooms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.236-243
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• 2018

The purpose of this study was to investigate the mediating effects of parental attachment and ego resiliency in the tendency toward social networking site (SNS) addiction in college students. For this purpose, 382 college students in the Jeju area were surveyed and their responses analyzed. To analyze the collected data, structural equations were implemented using SPSS Statistics version 18.0. According to the results of the study, there is a significant negative correlation between attachment formation and SNS intoxication in college students, and a negative correlation between ego resiliency and SNS addiction. Also, there is a significant positive correlation between formation of parental attachment and ego resiliency in college students, indicating that parental attachment and ego resiliency are significant factors in lowering SNS addiction. Second, in order to examine the mediating effects of ego resiliency in the relationship between the formation of parental attachment and SNS addiction in college students, a research model and a competition model were established and verified. As a result, the relationship between parent attachment and SNS addiction was mediated completely, and the research model is more appropriate. These findings suggest that ego resiliency is of practical significance in seeking ways to improve the problem of SNS addiction in the future. In other words, overuse of SNSs by university students can lead to addiction, but strengthening ego resiliency enables sound SNS use.

• Journal of Distribution Science
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• v.11 no.5
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• pp.43-53
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• 2013

Purpose - The purpose of this study is to analyze the effectiveness of customer relationship management (CRM) support policies for facilitating traditional markets, especially with respect to customer acquisition and maintenance, and to investigate the factors affecting CRM. Research design, data, and methodology - We analyzed the CRM efficiency of traditional markets in 16 cities and provinces in Korea on the basis of DEA analysis and Malmquist productivity analysis. The DEA model calculates a ratio of the weighted mean of various inputs to the weighted mean of various outputs and measures the efficiency of a specific decision making unit (DMU), which is compared to the reference group that has a similar input-output structure. The input variables are coupon, event, parcel service, premiums, while is the number of customers per day. Further, through regression analysis, we analyzed CRM-related factors affecting traditional markets' customer appeal and revenue growth. Results - We obtained the results of the efficiency of traditional markets in 16 provinces. The traditional markets in Seoul, Busan, and Jeju were found to be efficient in a model CCR that used the number of customers per day as an output variable, while Chungbuk, Jeonbuk Province, and According to the results of the DEA analysis and Malmquist productivity analysis, large cities such as Seoul, Busan, and Jeju showed efficiency in CRM-related investment businesses in traditional markets for attracting customers. The Malmquist analysis results confirmed that the productivity of traditional markets increased from 2008 to 2010. The results of the regression analysis revealed that the "customer acquisition/maintenance factor" and the "offering of customer convenience facility factor" were significant to the daily average number of customers, which is a dependent variable. The results of the test with the mediating variable, "number of customers," and the final dependent variable, "sales revenue," were rejected. However, the variable "customer acquisition /maintenance" was found to affect sales revenue positively. Conclusions - It is necessary to enhance the business not only for promotional activities to attract customers, but also to strengthen customer relationships among CRM businesses, such as through the management of key customers. The regression analysis results showed that CRM businesses have yet to produce an increase in sales revenues in traditional markets. Therefore, to help customers who visit traditional markets to keep buying products, it is necessary to prepare various investment methods and provide support to improve "customer loyalty." This study has a limitation in terms of CRM-related statistics. Therefore, in the future, it is necessary to conduct a survey of customers who use traditional markets to analyze the markets by type and size as well as the CRM-related factors. Based on the analysis, we will try to perform a variety of statistical analyses, including structural equations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.505-516
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• 2018

The purpose of the present study was to examine the mediating effect of self-concealment on the relationship between self-critical perfectionism and disordered eating behavior. Toward this aim, 348 participants responded to the measures of self-critical perfectionism, self-concealment and disordered eating behavior. Correlation analysis revealed that self-critical perfectionism was positively correlated with self-concealment and disordered eating behavior. In addition, self-concealment was positively correlated with disordered eating behavior. Structural equations analysis found that the relationship between self-critical perfectionism and disordered eating behavior had a significant partial mediating effect on self-concealment, meaning that self-critical perfectionism increased disordered eating behavior through high levels of self-concealment. This finding suggests that individuals who place high standards on themselves, and feature fear of negative evaluation from others, are at greater risk for disordered eating behavior. Based on this finding, we discussed suggestions for future research and clinical implications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.7-17
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• 2007

An analysis and design theory of an aperture-coupled cavity-fed back-to-back microstrip directional coupler is presented for the efficient and optimized design. For this purpose, an equivalent network is developed, and simple but accurate calculations of circuit element values are described. Design equations of the coupler are derived based on the equivalent circuit. In order to determine various structural design parameters, the evolutionary hybrid optimization method based on the genetic algorithm and Nelder-Mead method is invoked. As a validation check of the proposed theory and optimized design method, a 10 dB directional coupler was designed and fabricated. The measured coupling was 10.3 dB at 3 GHz, and the return loss and isolation were 31.8 dB and 30.5 dB, respectively. The directional coupler also showed very good quadrature phase characteristics. Good agreements between the measured and the design specifications fully validate the proposed network analysis and design procedure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.737-752
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• 1992

Analysis of elasto-dynamic deformation of flexible linkage mechanism is conducted using the finite element method. The equations of motion of the system are derived from the static structural problem in which dynamic inertia, gravitational and driving forces are treated as external loads. Linear spring model is included in the formulation of equation of motions to represent the effects of deformation of elastic bearings of revolute joints on the system behavior. A computer program is constructed and applied to analyze a specific crank-lever 4-bar mechanism. The algorithm of the program is as follows. First, the natural frequencies and the mode shapes of the system are calculated by solving the eigenproblem of the mechanism system which can be considered as a static structure by assuming the input shaft (crank shaft) to be fixed at any given configuration of mechanism. And finally, the elasto-dynamic deformation of the whole system is obtained using mode superposition method for the case of constant input speed. The effect of geometric stiffness on the mechamism is included in the program with the axial forces of links obtained through the quasi-static displacement analysis. It is found that the geometric stiffness exerts an important effect upon the elasto-dynamic behavior of the flexible linkage mechanism. Elastic deformation of bearing lowers the natural frequencies of the system, resulting smaller elastic displacement at the mid-point of the links and bigger elestic displacement at the ends of the links than rigid bearing. The above investigation of flexible linkage mechanism shows that the effects of the elastic deformation of bearing on the mechanism should be considered to design the mechanism which satisfies more preciously the purpose and the condition of design.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.370-374
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• 2013

The effects of zinc chloride addition on pore development of porous carbon nanofibers prepared by polyacrylonitrile (PAN)/ N,N'-dimethylformamide (DMF) (10 wt%) electrospinning were investigated. The change of morphological and structural modification by zinc chloride activation was investigated by a scanning electron microscopy (SEM) analysis. $N_2$ adsorption isotherm characteristics at 77 K were confirmed by Brunauer-Emmett-Teller (BET) and Horvath-Kawazoe (H-K) equations, and the curves showed the Type I mode in the International Union of Pore and Applied Chemistry (IUPAC) classification, indicating that lots of micropores exist in the sample. In addition, specific surface areas and total pore volumes of porous carbons prepared by the zinc chloride activation were determined as 600~980 $m^2/g$ and 0.24~0.40 $cm^3/g$, respectively. As experimental results, many holes or demolished structures were found on the fiber surfaces after the zinc chloride activation as confirmed by a SEM analysis. It was also observed that various pore sizes were found to be depended on the adding content of zinc chloride in PAN/DMF solution in this system.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.69-89
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• 2009

Reinforced and prestressed concrete (RC and PC) thin walls are crucial to the safety and serviceability of structures subjected to shear. The shear strengths of elements in walls depend strongly on the softening of concrete struts in the principal compression direction due to the principal tension in the perpendicular direction. The past three decades have seen a rapid development of knowledge in shear of reinforced concrete structures. Various rational models have been proposed that are based on the smeared-crack concept and can satisfy Navier's three principles of mechanics of materials (i.e., stress equilibrium, strain compatibility and constitutive laws). The Cyclic Softened Membrane Model (CSMM) is one such rational model developed at the University of Houston, which is being efficiently used to predict the behavior of RC/PC structures critical in shear. CSMM for RC has already been implemented into finite element framework of OpenSees (Fenves 2005) to come up with a finite element program called Simulation of Reinforced Concrete Structures (SRCS) (Zhong 2005, Mo et al. 2008). CSMM for PC is being currently implemented into SRCS to make the program applicable to reinforced as well as prestressed concrete. The generalized program is called Simulation of Concrete Structures (SCS). In this paper, the CSMM for RC/PC in material scale is first introduced. Basically, the constitutive relationships of the materials, including uniaxial constitutive relationship of concrete, uniaxial constitutive relationships of reinforcements embedded in concrete and constitutive relationship of concrete in shear, are determined by testing RC/PC full-scale panels in a Universal Panel Tester available at the University of Houston. The formulation in element scale is then derived, including equilibrium and compatibility equations, relationship between biaxial strains and uniaxial strains, material stiffness matrix and RC plane stress element. Finally the formulated results with RC/PC plane stress elements are implemented in structure scale into a finite element program based on the framework of OpenSees to predict the structural behavior of RC/PC thin-walled structures subjected to earthquake-type loading. The accuracy of the multiscale modeling technique is validated by comparing the simulated responses of RC shear walls subjected to reversed cyclic loading and shake table excitations with test data. The response of a post tensioned precast column under reversed cyclic loads has also been simulated to check the accuracy of SCS which is currently under development. This multiscale modeling technique greatly improves the simulation capability of RC thin-walled structures available to researchers and engineers.