• Journal of Power Electronics
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• v.17 no.5
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• pp.1173-1185
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• 2017

In this paper, a new single phase multilevel inverter topology with a single DC source is presented. The proposed topology is developed based on the concepts of the L-Z source inverter and the switched capacitor multilevel inverter. The input voltage to the proposed inverter is boosted by two steps: the first step by an impedance network and the second step by switched capacitor units. Compared to other existing topologies, the presented topology can produce a higher boosted multilevel output voltage while using a smaller number of components. In addition, it provides more flexibility to control boosting factor, size, cost and complexity of the inverter. The proposed inverter possesses all the advantages of the L-Z source inverter and the switched capacitor multilevel inverter like controlling the start-up inrush current and capacitor voltage balancing using a simple switching strategy. The operating principle and general expression for the different parameters of the proposed topology are presented in detail. A phase disposition pulse width modulation strategy has been developed to switch the inverter. The effectiveness of the topology is verified by extensive simulation and experimental studies on a 7-level inverter structure.

• The Journal of Bigdata
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• v.3 no.1
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• pp.83-94
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• 2018

The purpose of this study is to investigate how startup companies with the UGC platform service model can traverse the death valley for the company's survival with limited resources and create a mutually beneficial market. To do this, an interview-based exploratory study was conducted to analyze the cause and effect of each factor on the initial activation strategy of the UGC platform. For many start-up companies, this research helps minimize errors in strategic trial and error.

• Korea Trade Review
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• v.46 no.6
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• pp.39-54
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• 2021

This study comprehensively reviews the research conducted until recently in order to derive realistic alternatives in consideration of local industries. The case analysis was performed on a competitive port of similar size, and strategies and revitalization measures were suggested in consideration of the conditions of Gunsan Port. Literature review focused on papers and major reports. The case of similar size were analyzed for Daesan port, Boryeong port, and Mokpo port. In order to find strategies to revitalize the regional port logistics industry behind Gunsan Port, the recent opportunities and threat factors of Gunsan Port were derived. In order to foster the regional port logistics industry with Gunsan Port as its main base, this study proposes a three-step development strategy. It is necessary to increase the effectiveness of the public-private joint port sales and maintain the incentive system, but use it as a means to strengthen the competitiveness of Gunsan Port. Since the possibility of opening various routes is not high due to the conditions of Gunsan Port, various business models can be devised to link the currently opened routes. Start-up in the logistics field can stand out if they provide predictive data or provide consulting services by securing and analyzing logistics data, not directly providing logistics services.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.75-86
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• 2017

The development of web technologies and the generalization of smartphones have dramatically increased the number of social media users using the Internet. As a result, companies are perceived social media as a major marketing tool and operate a variety of SNS channels. In particular, start-ups conducting businesses with limited resources, social media is being used as an effective marketing tool to meet many potential customers at a low cost. Among them, facebook is the most used channel in the world and plays an important promotional tool not only in overseas but also in marketing activities of domestic start-ups. The purpose of this study is to analyze the relationship between satisfaction and purchase intention according to four personal characteristics of users who use social media contents and to measure the mediating effect of satisfaction on the relationship between content type and purchase intention. To this end, we classified into three types based on the previous research, and social media content is provided to 200 fans of Minbak Danawa(Minda), one of representative start-ups related to accommodation, The questionnaires were conducted for 3 weeks, and a total of 145 copies were collected. All the collected questionnaires were used for statistical analysis through SPSS 18.0. The empirical results show that all three types of content, such as task-oriented, self-oriented, and interaction-oriented, have a significant effect on the satisfaction level. Among them, it is confirmed that the satisfaction level plays a mediating role on the relationship between task-oriented contents and purchase intention. And the user 's personal characteristics showed a partially moderate effect on the satisfaction according to the content type. Therefore, social media content provided by corporations has an important effect on consumer satisfaction and purchasing, in order for start-up to prevail in the market, it is necessary to have an operational strategy to communicate with customers continuously through systematic contents analysis and planning. The result of this study suggests effective ways to build a social media marketing strategy for start-ups and suggests ways to utilize contents considering the characteristics of internet users.

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

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.153-158
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• 1995

All of the nuclear power plants in Korea we operating with analog instrumentation and control (I&C) equipment which are increasingly faced with frequent troubles, obsolescence and high maintenance expenses. Electrical and computer technology has improved rapidly in recent years and has been applied to other industries. So it is strongly recommended we adopt modern digital and computer technology to improve plant safety and availability. The advanced I&C system, namely, Integrated Intelligent Instrumentation and Control System (I$^3$CS) will be developed for beyond the next generation nuclear power plant. I$^3$CS consists of three major parts, the advanced compact workstation, distributed digital control and protection system including Automatic Start-up/shutdown Intelligent Control System (ASICS) and the computer-based alarm processing and operator support system, namely, Diagnosis, Response, and operator Aid Management System (DREAMS).

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.313-316
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• 2006

As Decentralized Generation(DG) becomes more reliable and economically feasible, it is expected that a higher application of DG units would be interconnected to the existing grids. This new market penetration of DG technologies is linked to a large number of factors like technologies costs and performances, interconnection issues, safety, market regulations, environmental issues or grid connection constrains. Korea Electric Power Corporation (KEPCO) has researched performance characteristics of the 60k W class 1) basic start-up & shutdown operation analysis 2) interconnection test 3) MGT -absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated. The suggested strategy and experience for the evaluation of the distributed generation will be used for the introduction of other distributed generation technologies into the grid in the future.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.146-151
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• 1992

A two-compartment four-cell model is developed for the adiabatic autoclave slim type reactor for free radical polymerization of low density polyethylene(LDPE). The mass and energy balances give rise to a set of ordinary differential equations, and by analyzing the system it is possible to predict properly not only the reactor performance but also the properties of polymer product. The steady state multiplicity is found to exist and examined by constructing the bifurcation diagram. The effects of various operation parameters on the reactor performance and polymer properties are investigated systematically to show that the temperature distribution plays the central role for the properties of polymer product. Therefore, it is essential to establish a good control strategy for the temperature in each compartment. In this study it is shown that the reactor system can be adoptively controlled by pole-placement algorithm with conventional PID controller. To accomplish a satisfactory control, the estimator and controller are initialized during the period of start-up.

• Journal of Industrial Technology
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• v.35
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• pp.9-13
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• 2015

In this paper, a new excitation scheme is developed to increase the output torque of the sensorless BLDC(Brushless DC) motor(BLDCM), which drives fins to control the flight attitude of a guided artillery munition. The proposed scheme is based on a 12-step excitation strategy combining two-phase and three-phase excitations. The proposed 12-step excitation scheme can produce more torque than a typical 6-step scheme for the start-up and synchronous operation in the sensorless BLDCM drive. The simulation and experimental results on the sensorless BLDCM drive system to control the fin were verified the validity of the proposed scheme.

• Journal of Distribution Science
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• v.13 no.6
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• pp.17-23
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• 2015

Purpose - Transnational corporations (TNCs) have influenced drastic changes (financial services, manufacturing, labor, technology transfer) in Central Eastern Europe (CEE). This paper examines the indirect changes in the CEE pattern of industrial development and market distribution. Research design, data, and methodology - Over 25 years, neighboring (or rival) countries competed to attract TNCs as a double-edged strategy for privatization and debt reduction. Through their experience attracting foreign direct investment (FDI), many countries started to reflect aspects of national capitalism. Countries also began to realize in 2010 that TNCs sought to enter markets with more favorable conditions for export-oriented manufacturing. Results - The analysis reveals that TNC investment strategies were aimed at eliminating local competition to acquire industrial "brown fields" to convert into "green fields." CEE countries have since strengthened their national systems and the support of large-scale state-owned enterprises and small and medium-sized start-up enterprises. Conclusions - CEE has changed based on industrial development and a regional structure of TNC market distribution and associated government policies. The pattern toward flexible markets gives countries the ability to further their economies.