• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.533-539
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• 2016

This study was performed to evaluate the characteristics of start-up of anaerobic digestion from food waste with different inoculum ratios. The hydrogen yield was similar with different inoculum ratios. The hydrogen production rate increased with increasing inoculum ratio. But the specific hydrogen production rate decreased with increasing inoculum ratio. Total volatile fatty acids composition analysis showed that butyrate and acetate were the prevalent products in all reactors, followed by lactate and propionate. The acetate was most prevalent product in reactors at $X_0/S_0=0.080$ and 0.159. But in reactors at $X_0/S_0=0.239$ and 0.318, butyrate accounted for greater than 50% of the total volatile fatty acids.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.1
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• pp.38-43
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• 2011

This paper presents the improvement of start-up characteristic of sensorless controlled IPMSM(Interior Permanent Magnet Synchronous Motor) with SMO(Sliding Mode Observer). It is difficult to utilize the rotor position information at starting point for the back EMF estimation based sensorless control. For this reason, open loop control is normally used during start-up period. However, changing from open loop to closed loop control might bring a problem on the transient characteristics for difference load conditions. To solve this problem, we add another rotor angle controller. Simulation results and experimental results are presented to verify proposed method.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.5
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• pp.115-125
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• 2019

This study examined the effects of entrepreneurship and perception of entrepreneurial environment on business performance. In particular, this study analyzed the difference in the effect of each independent variable on the dependent variable by using the government's participation in the start-up support project as a moderate variable. In order to achieve the purpose of this study, the researcher drew the variables corresponding to entrepreneurship and the variables related to entrepreneurship awareness. Innovativeness and risk sensitivity were selected as variables for entrepreneurship, and market environment and product environment were selected as variables for perception of entrepreneurial environment. Based on the above variables the research model was completed including the degree of participation in the government's start-up support project as a moderating variable. The data for the empirical analysis were collected from start-up companies in Daegu in 2018. A total of 601 questionnaires were collected and 399 copies of the data were used in this study after removing the unfaithful answers. The results of the analysis showed that innovation had a negative effect on management performance, and risk sensitivity, market environment, and product environment had a positive effect on management performance. In terms of the moderating effect, in the case of innovation, the higher the participation in government support projects, the lesser the negative effect. Risk sensitivity and product environment showed a strong impact on companies with a lot of government support projects, and the market environment had a strong impact on those who participated less. This study confirmed the importance and necessity of entrepreneurship and perception of entrepreneurial environment that influence the management performance of entrepreneurs. It is also meaningful in that it deals with the practical effects of the government's start-up support project on the start-up performance.

• STI Policy Review
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• v.7 no.2
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• pp.35-59
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• 2016

The strategic importance of innovation ecosystems has received increased attention from both the academic and policy perspectives. However, there is only limited empirical evidence on the importance of these ecosystems from the perspective of younger firms. This study focuses on the role of ecosystems for young innovative companies (YICs) and is based on a unique set of phone survey data from Finland and South Korea. The results are threefold: (1) Finnish YICs participate more actively in ecosystems than Korean YICs; (2) on average, Korean YICs report to have experienced lower ecosystem impact compared to Finnish YICs; (3) in both countries, key organizations of the ecosystems are represented on the board of directors in about one-third of the sample firms.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.765-771
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• 2011

This study was conducted to investigate the effect of heat treatment on the start-up performance for anaerobic hydrogen fermentation of food waste. The result showed that hydrogen production was $0.61{\pm}0.31$ mol $H_2$/mol hexose with heat-treatment of food waste at $70^{\circ}C$ for 60 min whereas it was $0.36{\pm}0.31$ mol $H_2$/mol hexose without heat-treatment of one. The heat treatment of food waste enhanced hydrogen yield due probably to the increase of hydrolysis as well as the decrease of non-hydrogen fermentation microorganisms. The removal efficiency of carbohydrate in reactors regardless of heat treatment of food waste maintained over 90%. The hydrogen conversion efficiency from food waste was 1.7-6.3% with heat-treatment whereas it was 0.7-4.5% without heat-treatment. At the time of switchover from batch to continuous operation, lactate concentration was high compared to the n-butyrate concentration in anaerobic hydrogen fermentation reactor without heat-treatment. Anaerobic hydrogen fermentation of food waste with heat treatment was stable in start-up periods because lactate concentration could be maintained at a relatively low compared to n-butyrate concentration due to the decrease of non-hydrogen fermentation microorganisms.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.3
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• pp.59-72
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• 2021

Research in which an individual's entrepreneurial spirit contributes to the country's economic development through revitalization of entrepreneurship is being actively conducted, but studies related to individual satisfaction or life satisfaction are still insufficient. This study aims to clarify the influence of young adults' entrepreneurial spirit on their life satisfaction and at the same time verify the mediating effect of self-efficacy and self-determination. In addition, an empirical analysis was conducted on 511 young people to reveal the effectiveness of participation in government start-up support projects. The research results are as follows. First, the entrepreneurial spirit had a positive effect on the life satisfaction of young people. Second, self-determination and self-efficacy played a role in mediating the relationship between entrepreneurship and life satisfaction. Finally, participation in start-up support projects did not show a statistically significant moderating effect. This study is expected to provide a clue that life satisfaction can act as a major variable in the impact of entrepreneurship on entrepreneurship. It also implies that the performance of the government start-up support project should be considered not only about the quantitative performance such as sales and employment effect, but also the qualitative performance such as personal life satisfaction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.40-50
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• 2016

In order to recover the power system during the wide power outage or power failure in the power plant, black start system should be properly operated without any problem. Especially power for black start in the geographically isolated areas of electric island is supplied from small emergency start-up generator, and loads are aux systems of gas turbines such as SFC(Static frequency converter). This paper introduces the international practices to overcome the voltage drop problem with harmonics of the system having the DC output such as SFC during black start in weak feed system and analyzes the relationship between house load inputs and harmonics. By varying the house load and input of power supply, this paper identified boundaries between weak feed and strong feed power. In order to verify the theory of stable condition in weak feed power system with DC output, house load is simulated using ETAP. Additionally MATLAB was used for harmonic analysis between the load inertia moment and non load inertia moment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.73-80
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• 2005

This paper addresses a newly proposed start-up method of the HAUSAT-2 momentum wheel. The HAUSAT-2 is a 25kg class nanosatellite which is stabilized to earth pointing by 3-axis active control method. A momentum wheel performs two functions. It provides a pitch-axis momentum bias while measuring satellite pitch and roll attitude. Pitch control is accomplished in the conventional way by driving a momentum wheel in response to pitch attitude errors. Precession control and nutation damping are provided by driving the pitch axis magnetic torquer. A momentum wheel is nominally spinning at a particular rate and changes speed. This simulation study investigates the feasibility and performance of a proposed strategy for starting-up the wheel. A proposed strategy to start-up the wheel shows that a pitch momentum wheel can be successfully started-up to its nominal speed from rest and be stabilized to nadir pointing.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.2
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• pp.109-121
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• 2021

With the recent increase in senior retirement, and senior start-ups are becoming more active due to high interest in start-ups. Research on young entrepreneurship, including college students, is being actively conducted, but most of the preceding research on senior entrepreneurship was conducted mainly on personal characteristics and social environment, and there were not many empirical studies on the influencing factors of entrepreneurship support policies. In this study, research and discussion on the entrepreneurial support policy and entrepreneurial competence as the influencing factors of senior entrepreneurship. As the independent variable of this study, the founder's competency was adopted as two factors: technical competence and creative competency, and the entrepreneurial support policy was divided into education support and funding support. Mentoring was set as a controlling variable and entrepreneurial intention was set as a dependent variable. A total of 232 questionnaires collected from seniors in their 40s or older were empirically analyzed. To verify the hypothesis of the study, SPSS 23 was used for exploratory factor analysis and regression analysis, and Process 3.4 was used for moderation effect. As a result of the study, it was found that the factors of technical competence, creative competence, educational support, and funding all have a significant influence on the will of entrepreneurship. It was found that creative competency(𝛽=.318), funding support(𝛽=.188), educational support(𝛽=.152), and technical competence(𝛽=.139), in this order, influenced the entrepreneurial intention. It was verified that the moderating effect of mentoring was significant between technical competence, creative competence, and entrepreneurial intention, but the moderating effect of mentoring between educational support, funding and entrepreneurial intention was not. The implications of this study will contribute to the research of senior start-up support policies, institutional supplementation, and differentiated start-up support programs by studying the factors of senior start-up capabilities and start-up support policies. It is also believed that it will contribute to the search for ways to increase creative capabilities that have a high influence on the willingness to start a business and the expansion of mentoring functions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.1
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• pp.129-141
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• 2015

The mentoring program, conducted as part of an entrepreneurship education program by the Business Incubator, has been acknowledged to help entrepreneurs feel less anxious and fearful of embarking on new business endeavors and the possibility of failure and gain a positive view toward starting new businesses. For this reason, the investment into and the contents of the program have been reinforced. Accordingly, this study aims to examine the effects of mentoring functions on the improvement of the entrepreneurial mindset of young entrepreneurs and verify the moderating effect of the start-up preparation period between the mentoring functions and start-up competence as a means to analyze the interaction effect of the business start-up preparation period between the mentoring functions and entrepreneurship. For the purpose of this study, the SPSS 18.0 statistical program was used to perform validity, reliability and hierarchical factor analyses of the survey data obtained from 156 subjects, who took part in the entrepreneurship mentoring program. The results of the analyses showed that the mentoring functions had a positive impact on the progressiveness and risk-taking aspects of entrepreneurship and a negative impact on innovativeness. On the other hand, the business start-up preparation period had a significant moderating effect between the mentoring functions and the progressiveness and risk-taking aspects. Based on these results, it was deemed that while the mentoring functions efficiently improved the progressive and risk-taking characteristics of potential entrepreneurs, they were not efficient in improving their innovativeness. Also, the application of the entrepreneurship mentoring program according to the start-up preparation period had an interaction effect in which the progressiveness and risking-taking aspects of entrepreneurship were improved. Based on these findings, a proposal was made in regard to the development of a tailored mentoring program that reflects the various characteristics of the entrepreneurs and their start-up preparation periods as a means to improve their entrepreneurial mindset.