• Journal of IKEEE
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• v.27 no.3
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• pp.319-326
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• 2023

In this paper, simulation and experimental results are presented, including the implementation of a digital controller for robust output voltage control of a single-phase voltage source inverters (VSIs) and total harmonic distortion (T.H.D.v) analysis. Typically, the VSIs uses a proportional integral (PI) controller for the current controller on the inner loop and a proportional resonant (PR) controller for the voltage controller on the outer loop to control the output voltage. However, non-linear loads still produce high-order odd harmonic distortion. Therefore, in this paper, a proportional multiple resonance (PMR) controller with a resonance controller for odd harmonic frequencies is proposed to suppress harmonic distortion. Analyze the frequency response of controllers for VSI plants and design PMR controllers. Through simulation, the total harmonic distortion characteristics of the output voltage are compared and verified when PI and PMR are used as voltage controllers. Both linear and non-linear loading conditions were considered. Finally, the effectiveness of the PMR controller was demonstrated by applying it to a 3kW VSIs prototype.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.45-68
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• 2022

The objective of this study is to investigate the factors which influence biotechnology scientists' data sharing intention. This study employed Ostrom's theory of collective action. The target population of this study includes scientists and students of biotechnology field in South Korea. A total of 411 responses which collected by e-mail were used for the final data analysis. The summary of this study is as follows. First, norm of data sharing and academic reciprocity were found to have significant positive influences on data sharing intention directly. Second, perceived community trust was found to have significant positive influences on data sharing intention when academic reciprocity was the mediator. Third, academic reputation showed the moderating effects on the relationship between norm of data sharing and academic reciprocity, and between norm of data sharing and data sharing intention. These findings show that researchers can approach the data sharing behaviors by using the mechanism of trust, norms, reciprocity, and reputation and indicate necessity for a development of academic reputation system to promote more data sharing behaviors of researchers.

• Design Convergence Study
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• v.14 no.1
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• pp.1-13
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• 2015

The purpose of this paper is to find out what values users pursue from a smart device based education service. For this purpose, a survey was conducted using a questionnaire that was developed based on the results of literature review and user interviews. Thirteen user expectation values were developed from the results of the survey: individually customized learning, anytime anywhere learning, learning for career, learning through interaction, learning from diverse resources, learning through cooperation, learning through interchange, self-directed learning, learning within actual context, learning with feedback, learning in spare time, learning with motivation & compensation, and step-by-step learning. In addition, the results of the survey also showed that the user expectation values of women, high school students and people who responded that they knew the smart device based education service very well were higher than those of other users.

• Journal of the Korean School Mathematics Society
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• v.26 no.2
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• pp.159-184
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• 2023

In this study, after defining motivating efficacy operationally, we developed a draft of the Motivating Efficacy Scale for Mathematics Teachers (MESMT), a measure of mathematics teachers' motivating efficacy, through the literature review and an expert Delphi survey, and conducted the exploratory factor analysis using online survey responses from 347 elementary and secondary mathematics teachers across the country to explore the factor structure of the measure and to test its validity and reliability. The exploratory factor analysis resulted in the deletion of 17 items from the initial 42 items developed through the literature review and expert Delphi survey and the identification of four factors (Providing successful experiences, Eliciting attention and engagement, Creating mathematics case-based relevance, and Providing extrinsic rewards), resulting in a final MESMT of 25 items. The MESMT developed in this study is a valid and reliable measure of mathematics teachers' motivating efficacy, and is expected to serve as a starting point for many subsequent studies to understand mathematics teachers' motivating efficacy and improve mathematics teachers' ability to motivate students' mathematics learning.

• Korean Journal of Culture and Social Issue
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• v.18 no.2
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• pp.153-167
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• 2012

This study was focused on five factors of Hasteful behavior and conducted to examine characteristics of the factors with relationship between Hasteful behavior and type A behavior. 207 adults(18-59 aged) answered the Hasteful Behavior Questionnaire and Type A Behavior Questionnaire. 136 items in established type A behavior or type A personality scale were collected. 136 items were reduced to 6 factors and 29 items. The components of Type A Behavior consists of success striving, impatience, failure anxiety, job immersion, activity, quickness. The factor analysis of Hasteful Behavior resulted in five factors. This was consistent in priority research. Each factors of Hasteful Behavior and type A behavior showed positive correlation. Hasteful behavior under time pressure had positive relations with success striving, failure anxiety, job immersion, activity, and quickness. Hasteful behavior under uncomfortable or isolation had a relation with impatience. Hasteful behavior in bordem had positive relations success striving, activity and quickness. Hasteful behavior in expectation of rewards had positive relations with success striving, impatience, failure anxiety, and quickness.

• Journal of agricultural medicine and community health
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• v.47 no.4
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• pp.211-219
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• 2022

Objective: This study was conducted to investigate the awareness of work-related disease prevention of farmers. Method: As a research method, a qualitative focus group interview was conducted in 18 participants. Results: Prevention and management services for work-related diseases of farmers mostly are based on research from other fields and so are not highly effective because their content is not relevant to agricultural work. It has been suggested that such program designers be required to have some appropriate related knowledge, and that incentives and a certification system for participation in such education be established. To analyze work-related diseases of farmers, fields of prevention, diagnosis, treatment, and rehabilitation should be created. They demanded the designation of hospitals and the actualization of compensation for farmers' safety insurance. The work-related diseases to address were include musculoskeletal diseases, pesticide poisoning-related diseases (cardiovascular disease, respiratory disease), psychiatric diseases such as depression, and allergic diseases. However, this must have been the result of the harmful factors they felt during agricultural work. And for farmer patients diagnosed with work-related diseases, it was said to strengthen farmer safety insurance. Conclusion: In order to increase the safely and health effects of agricultural work, it is necessary to prevent and manage work-related diseases of farmers. Projects should be developed in consideration of cultural and economic barriers of farmers and the characteristics of the work.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.21-30
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• 2013

It is a challenging problem to most of the image processing when the light source is unknown. The color of the light source must be estimated in order to compensate color changes. To estimate the color of the light source, additional assumption is need, so that we assumed color distribution according to the light source. If the pixels, which do not satisfy the assumption, are used, the estimation fails to provide an accurate result. The most popular color distribution assumption is Grey-World Assumption (GWA); it is the assumption that the color in each scene, the surface reflectance averages to gray or achromatic color over the entire images. In this paper, we analyze the characteristics of the camera response function, and the effect of the Grey-World Assumption on the pixel value and chromaticity, based on the inherent characteristics of the light source. Besides, we propose a novel method that detects important pixels for the color estimation of the light source. In our method, we firstly proposed a method that gives weights to pixels satisfying the assumption. Then, we proposed a pixel detection method, which we modified max-RGB method, to apply on the weighted pixels. Maximum weighted pixels in the column direction and row direction in one channel are detected. The performance of our method is verified through demonstrations in several real scenes. Proposed method better accurately estimate the color of the light than previous methods.

• Journal of Intelligence and Information Systems
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• v.24 no.3
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• pp.45-66
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• 2018

Crowdfunding has become more popular than angel funding for fundraising by venture companies. Identification of success factors may be useful for fundraisers and investors to make decisions related to crowdfunding projects and predict a priori whether they will be successful or not. Recent studies have suggested several numeric factors, such as project goals and the number of associated SNS, studying how these affect the success of crowdfunding campaigns. However, prediction of the success of crowdfunding campaigns via non-numeric and unstructured data is not yet possible, especially through analysis of structural characteristics of documents introducing projects in need of funding. Analysis of these documents is promising because they are open and inexpensive to obtain. We propose a novel method to predict the success of a crowdfunding project based on the introductory text. To test the performance of the proposed method, in our study, texts related to 1,980 actual crowdfunding projects were collected and empirically analyzed. From the text data set, the following details about the projects were collected: category, number of replies, funding goal, fundraising method, reward, number of SNS followers, number of images and videos, and miscellaneous numeric data. These factors were identified as significant input features to be used in classification algorithms. The results suggest that the proposed method outperforms other recently proposed, non-text-based methods in terms of accuracy, F-score, and elapsed time.

• The Journal of Korean society of community based occupational therapy
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• v.6 no.2
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• pp.11-20
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• 2016

Objective : The objective of this study was to evaluate the effects of rehabilitation therapists' general characteristics and job involvement on stress. The subjects of this study were occupational therapists and physical therapists working for long-term hospitals and general hospitals located in K and B cities, South Korea. Methods : The study investigated general characteristics, job stress, and job involvement by using questionnaires. Analysis conducted on total 144 questionnaires excluding 19 questionnaires, which did not satisfy the subject selection criteria. Results : The results show that job involvement had significantly positive correlations with job requirement, job autonomy, relationship conflicts, organization system, inappropriate compensation, job instability, and workplace culture. Secondly, marital status, wage level, and job engagement explained 46.6% of variations in job stress. Conclusion : The study was meaningful in examining the variables influencing the job stress of rehabilitation therapists. We expect that it can be used for improving the job environment of rehabilitation therapists.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.525-534
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• 2019

The study was carried out by surveying 500 fostered teenagers at youth shelters in the Capital area via onsite visit over about three weeks from April 17 to May 10, 2018; 487 samples out of 500 questioned subjects were used for the final analysis. The results of this study are as follows. First, the career decision self-efficacy was verified to have a partial mediating effect between all of self-leadership variables and the career maturity of the fostered adolescents at youth shelters. Second, the career decision self-efficacy was verified to have a partial mediating effect between the action-oriented strategy, which is one of the self-leadership variables, and the career maturity of the fostered adolescents at youth shelters. Third, the career decision self-efficacy was verified to have a partial mediating effect between the natural compensation strategy, which is one of the self-leadership variables, and the career maturity of the fostered adolescents at youth shelters. Fourth, the career decision self-efficacy was verified to have a full mediating effect between the constructive thinking strategy, which is one of the self-leadership variables, and the career maturity of the fostered adolescents at youth shelters.