• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.428-437
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• 2007

The potential for humic substances to serve as terminal electron acceptors in microbial respiration and the effects of humic substances on microbial azoreduction were investigated. The dissimilatory azoreducing microorganism Shewanella decolorationis S12 was able to conserve energy to support growth from electron transport to humics coupled to the oxidation of various organic substances or $H_2$. Batch experiments suggested that when the concentration of anthraquinone-2-sulfonate (AQS), a humics analog, was lower than 3 mmol/l, azoreduction of strain S12 was accelerated under anaerobic condition. However, there was obvious inhibition to azoreduction when the concentration of the AQS was higher than 5 mmol/l. Another humics analog, anthraquinone-2-sulfonate (AQDS), could still prominently accelerate azoreduction, even when the concentration was up to 12 mmol/l, but the rate of acceleration gradually decreased with the increasing concentration of the AQDS. Toxic experiments revealed that AQS can inhibit growth of strain S12 if the concentration past a critical one, but AQDS had no effect on the metabolism and growth of strain S12 although the concentration was up to 20 mmol/l. These results demonstrated that a low concentration of humic substances not only could serve as the terminal electron acceptors for conserving energy for growth, but also act as redox mediator shuttling electrons for the anaerobic azoreduction by S. decolorationis S12. However, a high concentration of humic substances could inhibit the bacterial azoreduction, resulting on the one hand from the toxic effect on cell metabolism and growth, and on the other hand from competion with azo dyes for electrons as electron acceptor.

• Korean Journal of Social Welfare Studies
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• no.37
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• pp.295-318
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• 2008

The purpose of this study is to examine the validity of adolescent's status offenses model based on general strain theory. To perform this research, a survey was conducted to adolescents of mixed gender from middle and high schools in Seoul and Gyeonggi Province, who were 9th to 11th grade students. A total of 1167 cases were collected, and without 27 inappropriate cases, 1140 cases were used for the analysis. A structural equation model was applied to the child abuse experience with depression mediator and the adolescents status offense, and the calculation of model fit index reached to .986(TLI), .994(CFI), and .032(RMSEA). The result of Aroian test on the effectiveness of depression as a mediator demonstrates that depression has a prominent effect as a mediator to the model. However, the self control of an adolescent, which were presented in this research as a primary moderating variable, did not display any salient effect on the course of a depression developing to the level of status offense.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.229-238
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• 2018

The purpose of this study is to investigate the mediating effect of learners' learning flow in the effect of presence on academic achievement in web-based e-learning. For this purpose, this study analyzed the influencing relationship between the each factor based on the structural model with the learning flow as a mediator variable. Based on existing theoretical studies, learning satisfaction and academic achievement, which represent learning outcomes, are set as dependent variables, and teaching presence, cognitive presence, and social presence are set as independent variables. Data collected from a total of 256 e-learning learners were used in the analysis of this study. According to the results of the analysis, teaching presence, cognitive presence, and social presence were found to have a significant effect on academic achievement when a learning flow is a mediator variable. Concretely, teaching presence, cognitive presence, and social presence have a positive effect on the learning flow, while learning flow has a positive effect on learning satisfaction. On the other hand, learning flow has a negative effect on academic achievement. As a result of verifying the mediating effect of learning flow on the relationship between presence, learning satisfaction, and academic achievement, there was meditating effect in the aggregate. This study implies that in order to increase the level of learning satisfaction and academic achievement, it is necessary to make the teaching-learning design in the provision of contents and materials for e-learning so that the learner can feel the presence. The results of this study can be used as a basic data for seeking support and promotion strategies for enhancement of future learning flow and presence.

• Korean Journal of Child Studies
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• v.27 no.5
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• pp.143-157
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• 2006

This study examined the mediating roles of parent and peer attachment in the relationship between academic stress and suicidal impulse among Korean adolescents. The 2959 ninth grade students in this study were selected from among 3211 students(excluding missing cases) who participated in the Korean Youth Panel Study. Following Baron & Kenny's(1986) suggestion, the mediator model was employed to analyze parent and peer attachment. Results showed that academic stress had a significant relationship with adolescent's suicidal impulse. Parent attachment acted as a partial mediator between academic stress and suicidal impulse; that is parent attachment provided a protective mechanism minimizing the direct effects of academic stress. However, peer attachment had no significant relationship with academic stress.

• Journal of Korean Society for Quality Management
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• v.45 no.2
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• pp.275-292
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• 2017

Purpose: This study is designed to explore web-site service quality factors in job information site for high quality human resource, and to test relationship among web service quality, image, user satisfaction, relationship quality, and loyalty intention. Methods: A survey tool was questionnaire that had obtained validity and reliability through literature survey and pretest survey, and sample 214 was analyzed through SEM using SPSS21.0 and AMOS21.0. Results: Web design and information offer affect Image and user satisfaction. Also, relationship quality turned out to be an important mediator between image and loyalty intention and between customer satisfaction and loyalty intention. Conclusion: This study shows that two factors in via of relationship quality, were important factors that related companies have to emphasize to raise performance, Also, in order to raise loyalty intention of customer, marketer should exert to well manage relationship quality having significance as a mediator.

• Korean Journal of Human Ecology
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• v.16 no.2
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• pp.433-442
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• 2007

The purpose of this study was to examine the mediating role of attitude, subjective norm, and perceived behavioral control on the relationships between past behavior and customers' intention to engage in exit of dissatisfaction responses. Results of the study demonstrated that the past behavior significantly improved the predictability of the voice of dissatisfaction response intentions. Furthermore, the mediating analyses indicated that the influence of past behavior was mediated by mediator. In the contests of exit behavior, the effect of past behavior on intention to exit was mediated by attitude, subjective norm and perceived behavioral control.

• Journal of Korean Academy of Nursing
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• v.38 no.4
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• pp.603-611
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• 2008

Purpose: This study was to determine the mediator or moderator role of empowerment in the relationship between the head nurse's transformational leadership and organizational commitment as perceived by staff nurses. Methods: Data was collected from 451 nurses in a tertiary hospital located in B city by means of structured questionnaires. Data was analyzed with descriptive statistics, Pearson's correlation coefficient and hierarchial multiple regression using the SPSS program. Results: Empowerment showed mediating effects between the head nurse's transformational leadership and organizational commitment as perceived by staff nurses. However, empowerment did not show moderating effects. Conclusion: Nurses' perception of empowerment, the head nurse's transformational leadership and organizational commitment have a strong relationship. This finding suggests the importance of empowering nurses to increase organizational commitment.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.5
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• pp.615-622
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• 2006

The purpose of this study was to examine the mediating role of attitude, subjective norm, and perceived behavioral control on the relationships between past behavior and customers' intention to engage in negative word-of-mouth communication of dissatisfaction responses. Results of the study demonstrated that the inclusion of past behavior improved the predictability of the negative word-of-mouth communication of dissatisfaction response intentions. Furthermore, the mediating analyses indicated that the influence of past behavior was mediated by the mediator. In the contests of negative word-of-mouth communication, the effect of past behavior on intention was partially mediated by attitude, subjective norm and perceived behavioral control.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.550-563
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• 2016

This study examined well-being as a mediator between self-discrepancy and dropout intention of junior college Student. 270 students in Busan answered the questionnaire about self-discrepancy, well-being, dropout intention. Structural equation modeling indicated that there were the complete mediating effect of well-being in the relationship between self-discrepancy and dropout intention. It indicated discrepancy between individuals' representation of their actual self(their actual self-state) and their representation of individual's hopes and aspirations(their ideal self-guide) affects junior college students' dropout intention, and well-being mediate process of self-discrepancy leading to dropout intention. This conclusion provide the significant implications that help preparing psychosocial intervention strategy for junior college students to decrease dropout intention and intervention strategy to enhance their well-being.

• Journal of the Korean Society of Food Culture
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• v.21 no.5
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• pp.500-506
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• 2006

The purpose of this study was to examine the mediating role of attitude, subjective norm, and perceived behavioral control on the relationships between past behavior and customers' intention to engage in voice of dissatisfaction responses. Results of the study demonstrated that the inclusion of past behavior improved the predictability of the voice of dissatisfaction response intentions. Furthermore, the mediating analyses indicated that the influence of past behavior was mediated by mediator. In the contests of voice behavior, the effect of past behavior on intention was not mediated by attitude and perceived behavioral control. Meanwhile, subjective norm mediated the relationship between past behavior and the intention to engage in voice behavior.