• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.17-22
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• 2009

Thermal stress and elastic creeping stress analysis was conducted by finite element method to simulate start-up process of a boiler header of 500MW standard fossil power plant. Start-up temperature and operating pressure history were simplified from the real field data and they were used for the thermal stress analysis. Two kinds of thermal stress analysis were considered. In the first case only temperature increase was considered and in the second case both of temperature and operating pressure histories were considered. In the first analysis peak stress was occurred during the temperature increase from the room temperature. Hence cracking or fracture may occur at the temperature far below the operating maximum temperature. In the results of the second analysis von Mises stress appeared to be higher after the second temperature increase. This is due to internal pressure increase not due to the thermal stress. When the stress components of radial(r), hoop($\theta$) and longitudinal(z) stress were investigated, compression hoop stress was occurred at inner surface of the stub tube when the temperature increased from room temperature to elevated temperature. Then it was changed to tension hoop stress and increased because of the operating pressure. It was expected that frequent start-up and shut-down operations could cause thermal fatigue damage and cracking at the stub tube hole in the header. Elastic-creeping analysis was also carried out to investigate the stress relaxation due to creep and stabilized stress after considerable elapsed time. The results could be used for assessing the creep damage and the residual life of the boiler header during the long-tenn service.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.1
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• pp.71-87
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• 2020

As startup companies are recognized as the important source of job creation and economic growth, the study is trying to find out the current situation of startup companies and their success factors in South Korea. The study analyzes the success factor of Woowa Brothers recognized as a unicorn start-up company in 2018 by using ERIS model and Start-up Developmental Stages. The ERIS model emphasizes Entrepreneurs, Resources, Industry Environment and Strategy for company performance and three developmental stages are divided into initiation, commercial and growth stages. The results indicate that the Woowa Brothers' success factor was to catch the appropriate timing in ERIS and to combine unique methods by differentiating itself from existing competitors at each stage. With analyses of success factor of Woowa Brothers as a case model, the study reveals limitations and recommends the direction of future research for producing more unicorn companies in South Korea.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.570-579
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• 2021

Compared to men, women experience difficulties in fund-raising, which can be a fundamental impediment to the success of women entrepreneurs. In this study, we examine whether is a difference between genders in the initial funding performance of start-up companies and confirm whether there are differences in organizational factors and entrepreneur factors that affect the initial funding performance. Data were collected through a survey of technology-based start-up companies located in the metropolitan area, and 287 companies were used for hypothesis analysis. The results reveal that there was a significant difference between genders in the investment attraction performance of early-stage entrepreneurs. In addition, as a result of the split-group regression analysis, it was found that in the case of men, firm age, early firm size, starting capital, engineering major had a significant effect on men. However, in the case of the women's group, it was confirmed that all the variables related to the organizational factors and entrepreneur factors were not significant. This study indirectly suggests that prejudices such as gender role stereotypes actually affect economic activities related to investment attraction activities.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.679-690
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• 2018

This study investigated what factors influenced the willingness to work( or start-up) of the self-support program participants. And the hypothesis is that the willingness to work of the self-support program participants would be different according to their duration of program participation. The Survey was conducted participants in 11 local self-support center of Incheon Metropolitan city in the year 2013 and 2016. And it has been analyzed the factors affecting the willingness to work of long-term and short-term participants. The results of this study are as follows. First, the factors affecting all participants's willingness to work ( or start-up) were gender, educational background, experience of employment or start-up, availability of self-support allowance, familiarity with local self-support center's staff, attitude toward work, period of self-support subject participated. Second, long-term participants were affected by disability, educational background, experience of employment or start-up, and availability of self-support allowance. Finally, in the case of short-term participants, it was found that educational background, experience of employment and start-up, availability of self-support allowance, family intimacy and intimacy with local self-support center's staff were influenced.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.157-160
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• 2008

Solar receiver in the solar power tower system has a similarity to a boiler of the thermal power plant in many aspects. However Boiler is operated long time without stopping while solar receiver repeats start and stop every day. The objective of this study is to investigate start-up characteristics of solar receiver. The experimental device was constructed in a bench scale. Basic experimental condition of water/steam was set by 25 bar and $223^{\circ}C$. Initially, the heat was added into risers only, then another experiment with input into drum additionally was done. When the heat flux was valid only risers, it took about 300 minutes until the water temperature in drum reached $223^{\circ}C$. Water temperature of drum was increased by $44^{\circ}C$/hr with 91.14 g/s of water circulation. With additional heat input into drum, 200 minutes was required to reach $223^{\circ}C$. In this case temperature was increased $66^{\circ}C$/hr with 96.5 g/s of water circulation.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.381-387
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• 2018

The purpose of this study is to make a lot of efforts for student employment in government or university. therefore We have developed Start-up Consulting courses that include easy to find jobs, convergence and multidisciplinary knowledge. The results of the comparison between university and graduate school, management consulting, and start-up consulting curriculum were reviewed according to STEAM 's rules. The results were divided into 5 main classes and 15 sub classes according to the 15 week subject. As a result of the study, we divided into 5 main classes and 15 sub classes in accordance with the 15 week subject. We were able to apply the understanding to the 1st stage company understanding(Arts), 2 stage consulting ability(Technology) 3 stage entrepreneurship strategy(Technology) 4 stage sub consulting(STEAM) 5 stage management case analysis(Arts).

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.57-68
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• 2021

The purpose of this study is to investigate the effect of location satisfaction of innovative start-ups, located in capital and non-capital areas, on the intention of relocation. The analysis was based on the data of a survey of 231 innovative start-ups that were founded less than 7 years ago. 10 factors related to the aspects of business management, network building, and business environment were considered as location satisfaction of start-ups. The dependent variable was whether innovative start-ups plan to relocate. First, it was confirmed that in the case of innovative start-ups in capital area, the intention to relocate was found to decrease when the location satisfactions related to the promptly provision of products and services to consumers and ease of supplying labor were increased. Second, in the case of innovative start-ups in non-capital area, it was found that the intention to relocate was found to decrease when the location satisfactions related to creating a network, convenient transportation and free and creative start-up environment were increased. In addition, it was found that the higher the sales of start-ups in non-capital area, the lower their intention to relocate while the higher firm age of start-ups in non-capital area, the higher their intention to relocate. This study has an academic contribution to examining the relationship between between the location satisfactions of start-ups and the intention to relocate, which has been rarely addressed in Korea, and to shedding light on the difference in capital and non-capital areas. Furthermore, this study has policy implications since it suggests factors that the government should consider for geographical agglomeration of start-ups.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.556-576
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• 2023

This study attempted to find a way to utilize idle spaces in rural areas as a way to respond to rural extinction. Based on the keywords "startup," "youth start-up," and "youth start-up+rural," start-up+rural," the study sought to identify the perception of idle facilities in rural areas through the keywords "Idle facilities" and "closed schools." The study presented basic data for policy direction and plan search by reviewing frequency analysis, major keyword analysis, network analysis, emotional analysis, and domestic and foreign cases. As a result of the analysis, first, it was found that idle facilities and school closures are acting importantly as factors for regional regeneration. Second, in the case of youth startups in rural areas, it was found that not only education on agriculture but also problems for residence should be solved together. Third, in the case of young people, it was confirmed that it was necessary to establish digital utilization for agriculture by actively starting a business using digital. Finally, in order to attract young people and revitalize the region through best practices at home and abroad, policy measures that can serve as various platforms such as culture and education as well as startups should be presented in connection with local residents. These results are significant in that they presented implications for youth start-ups in rural areas by reviewing start-up recognition for the influx of young people as one of the alternatives for the use of idle facilities and regional regeneration, and if additional solutions are presented through field surveys, they can be used to set policy goals that fit the reality.

• Journal of the Korean Regional Science Association
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• v.33 no.1
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• pp.17-27
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• 2017

The purpose of this study is to analyze the determinants of start-ups by industry based on the theoretical background of entrepreneurship. For this purpose, regional industrial structure and local labor market structure are considered in order to focus on regional factors in addition to economic factors, income factors, and technological innovation factors. As an analyzed result, three theories of entrepreneurship generally agree with the determinants of industry - specific entrepreneurship. During the economic recession, the number of start-ups has increased. The intra-regional consumption and the local government expenditure per capita have also positive effects on the start-up. The incubation center has a positive effect on the start - up in the manufacturing sector. Therefore, the academic-industrial leading various incubation facilities should be activated in addition to the central or local government leading incubation centers, which is a part of the policy to support start-ups of central and local governments. In addition, population growth is a very important factor in terms of potential demand creation, and the characteristics of regional industrial structure and the effect of human capital within the region differ by industry. In the case of the manufacturing industry, the accumulation effect positively influences the start-up of the industry. In other service industries, the human capital variable had the greatest effect on the start-up when all other conditions are constant.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.1-7
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• 2011

The analysis shows that the vibration is one of the main reasons of turbine failure. Especially, the problems caused by vibration occur right after retrofit of the turbine-generator and restarting the turbine. Through the case study of high vibration caused by after the turbine trip and restart, turbine vibration was identified to be influenced by startup condition. Turbine startup at high casing temperature right after unscheduled turbine trip cause radial expansion in rotor by contraction in axial direction, while casing continues to contract by steam flowing into casing. Consequently, gap between rotor and casing decrease until to metal contact to cause high vibration. Through the case study of high vibration of turbine-generator system after generator retrofit, it was identified that generator replacement could cause high vibration in turbine-generator system if the influence of generator replacement on entire system was not considered properly. To prevent startup delay caused by high vibration, it is important to keep the gaps at the design standard and start the turbine after thermal equilibrium.