• Journal of Engineering Education Research
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• v.18 no.2
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• pp.3-7
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• 2015

Entrepreneurship has been considered as an engine to lead economy, which has been resulting in a focus on entrepreneurship education to promote entrepreneurship. This paper focuses on science and engineering students, and analyzes the relationship between entrepreneurship education and entrepreneurship level. The response results of 950 students (34 universities) were as follows. First, the entrepreneurship level of science and engineering students are a little high but not as significant more than non-science and engineering. Second, science and engineering students have an impact on the level of entrepreneurship about entrepreneurship courses. Third, entrepreneurship courses and clubs have an effect on entrepreneurship level. As a conclusion, we have to improve the quality of entrepreneurship education, recognize startup as a credit, and build up entrepreneurship education ecosystem through the local area network.

• Journal of Power Electronics
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• v.18 no.2
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• pp.407-417
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• 2018

A novel family of Buck mode three-level direct ac converters with a high frequency link is proposed. These converters can transfer an unsteady high ac voltage with distortion into a regulated sinusoidal voltage with a low THD at the same frequency. The circuit configuration is constituted of a three-level converter, high frequency transformer, cycloconverter, as well as input and output filters. The topological family includes forward, push-pull, half-bridge, and full-bridge modes. In order to achieve a reliable three-level ac-ac conversion, and to overcome the surge voltage and surge current of the cycloconverter, a phase-shifted control strategy is introduced in this paper. A prototype is presented with experimental results to demonstrate that the proposed converters have five advantages including high frequency electrical isolation, lower voltage stress of the power switches, bi-directional power flow, low THD of the output voltage, and a higher input power factor.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1285-1290
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• 2018

Objective: This study shows the effects of dietary fiber levels on cecal microbiota composition in geese at day 70 according to pyrosequencing of the 16S ribosomal RNA gene. Methods: A total of 468 1-day-old healthy male Yangzhou goslings with similar body weight were randomly divided into 3 groups with 6 replicates per group and 26 geese per replicate. Geese were fed diets with fiber levels of 2.5% (low fiber level diet, Group I) and 6.1% (Group III) during days 1-70, respectively, or 4.3% for days 1-28 and 6.1% for days 29-70 (Group II). Results: Low fiber level diet decreased body weight, average daily gain during, increased lower feed conversation rate of geese during day 1 to 70 (p<0.05). Low fiber level diet decreased the total operational taxonomic units, Chao1 index and Shannon index, whereas increased the Simpson index of cecal microbiota in geese at day 70. Low fiber level diet decreased the relative abundance of Bacteroidetes, Firmicutes, Bacteroides, and Paraprevotella in cecum of geese at day 70. The similarity of cecal microbiota between low fiber level diet group and other groups was smaller. Conclusion: This study indicates that the low fiber level diet decreased diversity of microbiota, and relative abundance of some beneficial microbiota in cecum of geese at day 70, implying that the low fiber level diet has negative influence on performance by altering the diversity and population of cecal microbiota in geese.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.585-587
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• 1996

A simple regenerative snubber structure is proposed, which is applicable to multi-level inverter with series-connected GTOs for high power applications. The novel snubber structure can solve large energy loss problems and guarantee safe operation of power converter can be achieved. The proposed new snubber has the potential of high performance and high reliability and is particularly suitable to high power and multi-level application with series connected power devices. The snubber voltage and current waveforms are analized and shown the simulation and experimental results for a GTO 3-level inverter circuit with inductive load.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.263-270
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• 2016

This study was conducted to investigate the effects of raw material ratio on the physicochemical characteristics of emulsion-type pork sausages. Experiment design was divided into 12 treatments, based on protein level (P), fat level (3P, 3.5P, and 4P), and water level (4P+10, 4P+15, 4P+20, and 4P+25). The pH and shear force values were significantly higher in T7 (3.5P fat and 4P+20 water) than those of other treatments. The lightness and redness were greatly reduced by increasing the quantity of water. The treatments containing 3P fat and 4P+20 water had the highest values of cohesiveness, springiness, gumminess, and chewiness. On the whole, when the protein (P) and fat (3P, 3.5P, 4P) levels were fixed, an increase over the appropriate moisture level deteriorated many physicochemical characteristics.

• Asian Journal of Innovation and Policy
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• v.3 no.1
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• pp.25-49
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• 2014

We wanted to show the different group dynamics of factors for success and failure cases for technology commercialization in small technology-based firms. Existing studies are based on product level, project level, division level or firm level. We deal with technology level, and at small-technology-based firms. This is a longitudinal case study based on 8 cases from Korea. Our study on technology level is a first trial in success and failure studies unlike all existing studies. As a first step, we introduced new categories and factors such as technology attributes and CEO reflecting data, and especially a new concept of launch readiness level. Finally, we adopted correspondence analysis to show the group dynamics. The results are as follows; Technology factors are the most important factors. Second, resource-based factors are more critical in failure cases than success cases and technology factors are more critical to success.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.653-654
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• 2008

This paper presents a topological shape optimization for electromagnetic system using a level set method. The optimization is progressed by updating the implicit level set function from the Hamilton-Jacobi equation. The up-wind scheme is used for numerical implementation of the Hamilton-Jacobi equation. In order to validate the proposed optimization, the core part of a C-core actuator is optimized by three cases using different materials; (single steel), (two steels), and (steel and magnet).

• Korean Management Science Review
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• v.26 no.3
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• pp.157-167
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• 2009

Technology transition from defense technology to weapon system is an important process for defense acquisition program. Many countries such as USA, UK, Australia and Republic of Korea use technology readiness level (TRL) as a tool for technology transition by identifying critical technology elements (CTEs) and assessing the technology maturity. In this paper we review a transition process for the defense acquisition. Then we suggest a method to evaluate system's TRL using each component TRL and integration readiness level (IRL) between each technologies. We apply the method to an ACTD project. A result show that technology maturity is influenced by integration between technologies.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.1
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• pp.32-42
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• 2002

This study were conducted to reveal the awareness and competitiveness of Korean packaging industry in information technology(IT) and e-commerce. For the survey, 114 sample companies were selected representing all packaging materials, equipment and systems, institutes, consulting and trading companies. The trained interviewers spoke to the respondents who were at the position of packaging research and development and were considered knowledgeable about the level of IT in the company. The collected data were analyze in three major categories: IT fundamentals, usages, and company policy. From the results, packaging suppliers were at the very low level of IT fundamentals and uses compared to those of packaging users. The gap between packaging suppliers and users that access the Internet was seriously wide, and this trend was generally due to different size of company. Packaging suppliers were still at the basic level of information-oriented working environment.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1986-1995
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• 2018

In this paper, a novel neutral-point voltage balancing scheme for NPC three-level inverters using carrier-based sinusoidal pulse width modulation (SPWM) method is developed. The new modulation approach, based on the obtained expressions of zero sequence voltage in all six sectors, can significantly suppress the low-frequency voltage oscillation in the neutral point at high modulation index and achieve a fast voltage-balancing dynamic performance. The implementation of the proposed method is very simple. Another attractive feature is that the scheme can stably control any voltage difference between the two dc-link capacitors within a certain range without using any extra hardware. Furthermore, the presented scheme is also applicable to the single-phase NPC three-level inverter. It can maintain the neutral-point voltage balance at full modulation index and improve the voltage-balancing dynamic performance of the single-phase NPC three-level inverter. The performance of the proposed strategy and its benefits over other previous techniques are verified experimentally.