• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.1304-1306
• /
• 1996

A regenerative signal amplifying gate driver of self-excited electronic ballast is presented. It can be used for high pressure sodium (HPS) lamp without auxiliary external ignitor. Since the HPS lamp requires very high ignition voltage at start up, the resonant frequency of the circuit must be increased to obtain high voltage oscillations in spite of relatively small resonant current. The presented gate driver amplifies the current of gate drive transformer and raises the gate-source voltage Quickly to turn on the MOSFET switches. Hence, the resonant frequency can be increased more than 100kHz. The HPS lamp used in the simulation and experiment has the rating of 400W input power at 220V input ac voltage source. The experiments show that the resonant frequency is above 150kHz at start up.

• Wind and Structures
• /
• v.35 no.2
• /
• pp.121-130
• /
• 2022

In this paper, the issue of pitch control in a vertical axis wind turbine was tackled. Programming the Actuator Cylinder model in MATLAB, a theoretical optimum pitch solution was found and then a classic four-bar mechanism was adapted to that theoretical solution to achieve a simple and elegant control of the pitch in the turbine. A simulation using the mechanism worked to find the optimum pitch cycles, where it was found that the mechanism would, in fact, increase the efficiency of the VAWT, by at least 11% and in the best case, over 35%. Another aspect that is studied is the possibility of self-start of the turbine by only changing the pitch on the blades. This analysis, however, proved that a further individual pitch control must be used to surpass the cogging torque. All analyses conducted were done for a specific wind turbine that is 2 m² in the swept area.

• Journal of Digital Convergence
• /
• v.19 no.12
• /
• pp.151-156
• /
• 2021

This study is aim to verify the mediating effect of entrepreneurial spirit on non-financial performance and self-efficacy. In this study, data were collected through a survey to investigate the relationship between variables, and empirical analysis of the research hypothesis was conducted using multiple regression analysis. The results of the study are as follows. First, entrepreneurship has a positive effect on self-efficacy; second, it suggests that the stronger entrepreneurship, the better self-efficacy. In addition, self-efficacy can produce positive results in various aspects, especially through this study, self-efficacy has resulted in improvement of non-financial performance.The results of this study have a positive effect on the various convergence of start-ups and the establishment of a stable start-up culture in the era of the Fourth Industrial Revolution.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.19 no.1
• /
• pp.33-53
• /
• 2024

By identifying the relationship between Interest of Entrepreneurship and intention, this study clarifies the entire lifecycle process leading up to a college student's decision to start a business. We explore whether an individual's Interest of Entrepreneurship stemming from start-up activities and the interest of parents toward their children's start-up affect start-up intention. For this purpose, attitude toward start-up, subjective norms, and perceived behavioral control, which are components of the Theory of Planned Behavior (TPB), were set as parameters. Furthermore, start-up self-efficacy was established as a moderating variable to examine the relationships between factors and their importance. In addition, survey questionnaires were collected from 300 college students in Korea, and after excluding 18 insincere responses, a total of 282 were analyzed using SPSS 26 and AMOS 26. The main findings are as follows. First, an individual's Interest of Entrepreneurship has a significant impact on start-up intention, mediated by attitude toward start-up, subjective norms, and perceived behavioral control. Therefore, future college start-up education should apply the components of TPB to enhance its effectiveness, and various start-up activities should be provided to foster students' interest. Secondly, parents' interest in start-up has a significant impact on subjective norms and perceived behavioral control. Therefore, even if parents are interested in their children's start-up activities, such interest does not necessarily lead to favorable attitude. However, as it significantly impacts subjective norms and perceived behavioral control, start-up education targeting parents linked to these parameters could increase college students' Interest of Entrepreneurship and intentions.

• Journal of vocational education research
• /
• v.37 no.1
• /
• pp.119-138
• /
• 2018

The purpose of this study was to analyze the factors influencing of separation and the time of separation for middle and old aged self-employed workers. The cox proportional hazards model was used in the first survey of KLoSA, 684 persons who were over 40 years old in 2006, using data up to the 5th period of 2014. The main findings of this study are as follows. First, the average duration of job for middle and old aged self-employed workers in 2005 was 15.5years. Of the total 684 workers, 214(31.3%) person was found to have lost their job during survey period. Second, gender, age at start up, and education level have significant effects on job separation of them. When women, when they were older at start up, when they were graduate the university or higher, increased their risk of leaving their businesses. Third, in the characteristic of their work, the type of job and job satisfaction were found to affect to job desertion. When people are engaged in accommodation and food business rather than agriculture and forestry fishery, when the satisfaction of the work is lower, the risk was high. Based on these conlusions, the following implications are suggested. First, it is necessary to establish a support strategy for female middle-aged and old self-employed and older workers who start their own business after their 60s. Second, it is necessary to support them to enter into various fields by utilizing their own aptitude and experience rather than establishing them in industries with low entry barriers. Third, it is necessary to develop policies to help improve job satisfaction in the working environment. In particular, it is necessary to ensure that high educated self-employed workers are satisfied with various compensations by self-employed.

• Journal of Venture Innovation
• /
• v.6 no.3
• /
• pp.1-20
• /
• 2023

This study conducted an empirical analysis of whether the accelerator incubation program (mentoring, seed investment) and entrepreneur self-efficacy affect competitive advantage performance for start-up representatives who have experienced the accelerator incubation program. At this time, the mediating effect of innovation capability was also examined. As for sample collection, 334 samples collected from representatives of start-ups nurtured by national accelerators and regional centers for creative economy and innovation in Korea were tested using the Smart PLS 4.0 program, and the analysis results are as follows. First, mentoring has no significant effect on competitive advantage performance, whereas seed investment and entrepreneur self-efficacy have a positive (+) effect on competitive advantage performance. Second, mentoring, seed investment, and entrepreneurial self-efficacy have a positive (+) effect on innovation capability. Third, innovation capability has a positive (+) effect on competitive advantage performance. And fourth, it was confirmed that innovation competency has a positive (+) effect between mentoring, seed investment, entrepreneurship self-efficacy and competitive advantage, and has a mediating effect. As a result, while mentoring did not have a direct significant effect on competitive advantage performance, it was confirmed that there was a significant effect mediated by innovation capability. Seed investment, entrepreneur self-efficacy, and innovation capability directly helped competitive advantage performance, and it was confirmed that innovation capability has an effect on the competitive advantage performance as a mediating effect. It is expected that this study will be able to suggest a direction that can help start-ups improve their competitive advantage performance.

• International Journal of Advanced Culture Technology
• /
• v.5 no.1
• /
• pp.17-25
• /
• 2017

The purpose of this study was to investigate the effects of self-identity on body shape management for college students. This study used descriptive research to analyze the effects of self-identity, which has contained factors of Subjectivity, Self-acceptance, Future Confidence, Goal Orientation, Scrupulous. The subjects were 404 college students located in C province who were voluntarily agreed. Multiple regression analysis was conducted to verify the effects on self - identity and body shape management. As a result, self - acceptance of self - identity' subcomponents had no effect on body shape management, but future confirmation, goal orientation, Scrupulous, intimacy affects body shape management(P < 0.001). Based on these results, in order to manage the body shape of college students, it is considered effective to present the visible goals and apply the programs that students can do themselves. In addition, it can be seen that it is effective to start body shape management during college group life to enhance intimacy.

• Clinical Endoscopy
• /
• v.55 no.1
• /
• pp.128-135
• /
• 2022

Background/Aims: Recent reports suggest that the biliary self-expandable metallic stent (SEMS) is highly effective for maintaining hemostasis when endoscopic hemostasis fails in endoscopic retrograde cholangiopancreatography (ERCP)-related bleeding. We compared whether temporary SEMS offers better efficacy than angioembolization for refractory immediate ERCP-related bleeding. Methods: Patients who underwent SEMS placement or underwent angioembolization for bleeding control in refractory immediate ERCP-related bleeding were included in the retrospective analysis. We evaluated the hemostasis success rate, severity of bleeding, change in hemoglobin levels, amount of transfusion, and delay to the start of hemostasis. Results: A total of 27 patients with SEMS and 13 patients who underwent angioembolization were enrolled. More transfusions were needed in the angioembolization group (1.0±1.4 units vs. 2.5±2.0 units; p=0.034). SEMS failure was successfully rescued by angioembolization. The partially covered SEMS (n=23, 85.1%) was generally used, and the median stent-indwelling time was 4 days. The mean delay to the start of angioembolization was 95.2±142.9 (range, 9-491) min. Conclusions: Temporary SEMS had similar results to those of angioembolization (96.3% vs. 92.3%; p=0.588). Immediate SEMS insertion is considered a bridge treatment modality for immediate refractory ERCP-related bleeding. Angioembolization still has a role as rescue therapy when SEMS does not work effectively.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.6
• /
• pp.189-207
• /
• 2020

The government has achieved quantitative growth in university start-up education while supporting start-up education. However, it failed to systematize start-up education from an academic, policy, and practical perspective and to reveal the relationship between education and achievements in supporting start-ups. Therefore, there is a lack of interest and effort to promote effective education. In Europe, in-depth research has already been done over many years to establish an EntreComp system. Competences create values for others and attempt to apply them to education, viewing them as the people's lifelong competitiveness. On the other hand, it is urgent to improve the education system as domestic university start-up education is mainly focused on cultural level start-up skills and easy-to-access education from a business administration perspective. Based on this, the entrepreneurship competence-based start-up education system was designed. Next, eight EntreComp frames were drawn for university students through the Focus Group Interview (FGI) and Delphi survey methods, as well as domestic and international prior studies on EntreComp. In 2018, 919 start-up education programs of 42 start-up leading universities were conducted to derive the status of education by EntreComp. Prior studies of 25 entrepreneurship competences, including data from Bacigalupo et al.(2016), which studied EntreComp in the EU, were investigated and reflected the frequency of research and the importance of education and start-up perspectives. Based on the purpose of the university start-up education presented in this study, the entrepreneurship competence frame consisting of a total of eight, including spotting opportunities, value creation, self improvement, mobilising resources, technology application, strategic management, relationship, and learning through experience, was derived through expert verification. It also investigated the current status of education by competence, the degree of reflection of competence education, and the relationship with the results of support for start-ups that reflect the number of students enrolled in each university. Through this, it was suggested that future start-up education at universities could be improved from the EntreComp perspective. It has a differentiation in research in that it conducted a thorough survey using the data on start-up courses operated by leading startup universities for a certain period. However, it is difficult to generalize because the number of samples of leading startup universities is limited. Nevertheless, this study proposes the educational goal of advancing university start-up education from the perspective of entrepreneurial competence, cultivating future required competences, and fostering entrepreneurial talents that create value for others. In addition, it is meaningful in that it presents a clear direction for subsequent research by preparing a framework for research from a more essential perspective on the entrepreneurship competence frame.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.1
• /
• pp.13-28
• /
• 2022

Korean Government Budget Supports for startups have been spiked and resulted in increasing the number and scaling up Startup Accelerating managers. It have skyrocketed the strong demand for their qualified roles. However, unclear role description and gap between required role and their capability have discouraged startup manager's self-efficacy resulted in declining their full commitment and causing poor role performance. The focus of this research falls on empirical analysis to the effect of startup accelerating manager's capability characteristics on their full commitment and performance to start-up support groups. This research is expected to deliver diverse policy alternatives to build up manager's core competencies to accelerate their self-efficacy leading their full role commitments and finally pushing up policy performance. In addition, this research will found more strong literature review for the following researches in this emerging fields. This research is brought four highlighting results with respect to four research problems. First, it propose proper concept of startup accelerating manager based upon its legal entitlement. Second, it drive required core competencies of manager for successful their accountability. Third, it analyze the unique features of startup accelerating manger's capabilities against business incubation manger. Fourth, it empirically analyze in coming with government startup funding, the effect of self-efficacy including employment status, job environment, etc. on their organizational commitment and job performance. This research reveal the required unique core competencies of manger into founder sourcing ability, project managing ability, startup proving and pivoting ability, consulting ability for successful investment raising. As of this empirical research results, First, manager's ability have positively effect on their job performance, full commitment, and self-efficacy. Second, self-efficacy have a mediating effect on manager's ability, job performance, full commitment. This research derive key policy implication of requiring to build up more accelerating ability, of manager from the basics to advance level by customized and algorithm based traing program. This accelerating ability buildup program will not only surge self-efficacy of manger resulting in making full commitment and better job performance, but also devote to categorizing the unique new feature and position of manger as seed investment and supporter.