• Proceedings of the KSR Conference
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• 2009.05a
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• pp.959-965
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• 2009

To meet the demand increasing passengers in railway vehicles, railway transportation service companies are increasing the numbers of cars per train-set. Two solutions, Variable train-set formations and Multiple train-set operation, are common way to increase the transportation capability. These kind of long distance train-set can effect train-set command and control system, and sometimes the digital signals using train line from master cabin can not reach to the systems located the other extremity slave car. This is so called Voltage Drop. This phenomenon is originated from the electrical power consumption and electrical cable resistance, and cause to the equipments or cars located end of the electrical cable way, malfunction or abnormal operations. This voltage drop happens not only in train lines but also Battery Power Lines. The purpose of this investigation is to design high reliability railway vehicles by clarifying the possibility of happening these events case by case, by analyzing the reasons, and finally by finding the best solutions.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.815-820
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• 1998

Many composite girder bridges have been constructed for about thirty five years. Nowadays they are aged or deteriorated because of th increase in traffic and vehicle loads. In this study, the effect of strengthening with glass fiber sheet is investigated to estimate the possibility for appling for damaged prestressed concrete bridges. One normal and eight cracked specimens which had been preloaded were tested. The cracked specimens were strengthened with either external prestressing or bonding glass fiber sheet, or using both methods. The results showed that the maximum loads are almost same for both methods. So it seems that the strengthening with glass fiber sheet can be used for strengthening damaged prestressed concrete girders. It is important that proper devices should be selected to prevent glass fiber sheet from premature bonding failure below its maximum load, which is similar to end anchorage problem in external prestressing method. It is proved that the devices proposed in this paper have sufficient anchoring capability to increase load carrying capacity.

• Nuclear Engineering and Technology
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• v.45 no.4
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• pp.565-572
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• 2013

The fabrication methods and requirements of the fiber, interphase, and matrix of nuclear grade $SiC_f/SiC$ composites are briefly reviewed. A CVI-processed $SiC_f/SiC$ composite with a PyC or $(PyC-SiC)_n$ interphase utilizing Hi-Nicalon Type S or Tyranno SA3 fiber is currently the best combination in terms of the irradiation performance. We also describe important material issues for the application of SiC composites to LWR fuel cladding. The kinetics of the SiC corrosion under LWR conditions needs to be clarified to confirm the possibility of a burn-up extension and the cost-benefit effect of the SiC composite cladding. In addition, the development of end-plug joining technology and fission products retention capability of the ceramic composite tube would be key challenges for the successful application of SiC composite cladding.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.651-659
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• 2003

A new method was proposed to control Harmful Algal Blooms (HABs) by a biosurfactant sophorolipid. The effect of sophorolipid on the growth, motility, precipitation, and recovery of algal cells was investigated for four common HAB species, Scripsiella trochoidea, Prorocentrum minimum, Cochlodinium polykrikoides, and Heterosigma akashiwo. The motility and growth of algal cells were inhibited significantly at the concentration of 20 and 5 mg/l sophorolipid, respectively, and no recovery was observed under the above concentrations. The concentration of 20 mg/l sophorolipid was considered to be an effective concentration for the mitigation of HABs. A sedimentation test suggested that the maximum precipitation occurred at the end of 1 h, and the algicidal effect of sophorolipid was observed by a microscope. Comparative study showed that sophorolipid had marked algicidal capability. Analysis on biodegradability, toxicity, and cost effectiveness further demonstrated the potential of sophorolipid in future HABs mitigation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.116-121
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• 2009

Thermosonic flip chip bonding is an important technology for the electronic packaging due to its simplicity, cost effectiveness and clean and dry process. Mechanical properties of the horn and the shank, such as the natural frequency and the amplitude, have a great effect on the bonding capability of the transverse flip chip bonding system. In this research, two kinds of study are performed. The first is the new design of the clamp and the second is the effect of tolerance parameters to the performance of the system. The clamp with a bent shape is newly designed to hold the nodal point of the flip chip. The second is the effect of the design parameters on the vibration amplitude and planarity at the end of the shank. The variation of the tolerance parameters changes the amplitude and the frequency of the vibration of the shank. They, in turn, have an effect on the quantity of the plastic deformation of the gold ball bump, which determined the quality of the flip chip bonding. The tolerance parameters that give the great effect on the amplitude of the shank are determined using Taguchi's method. Error of set-up angle, the length and diameter of horn and error of the length of the shank are determined to be the parameters that have peat effect on the amplitude of the system.

• Knowledge Management Research
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• v.22 no.1
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• pp.121-138
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• 2021

In the rapidly changing business environment, the intention to start a new business is strengthening. In this study, in order to confirm the effect on the entrepreneurial intention, the relationship and the effect among technical capability, and job satisfaction, and entrepreneurship, which are the second order factor consisting of risk taking, desire for achievement, and innovativeness, on entrepreneurial intention were analyzed to identify the effect of business intentions from the perspective of knowledge management.. To this end, the proposed research model was statistically verified using the Partial Least Square Structural Equation Model. Under analysis, survey data were collected online for 280 employees currently in the workplace, and the research model was empirically analyzed through the structural equation model. As a result of the analysis, it was confirmed that all the suggested variables had a significant effect on the entrepreneurial intention, and that job satisfaction had a negative moderating effect on entrepreneurial intention by interacting with entrepreneurship. The results of this study are expected to provide practical and theoretical implications from a knowledge management perspective.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.375-388
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• 2019

This study attempted to investigate the effects of personal competency on job commitment and satisfaction through talent donation in the field of cosmetology. To this end, factor analysis, reliability analysis, and regression analysis was performed. A questionnaire was given to 374 cosmetology talent donors, and the results found the following: Personal competency revealed a highly significant correlation with talent donation, job commitment, and job satisfaction. However, for satisfaction with talent donation and job satisfaction, no considerable influence was found, even though they were partially significant. Furthermore, there was a highly significant correlation between job commitment and job satisfaction. It's been confirmed that participation in talent donation is influenced by the cosmetologists' personal competency. Therefore, this study proposed that it is a necessity to seek diverse options to enhance competency.

• Journal of Advanced Navigation Technology
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• v.25 no.4
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• pp.267-272
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• 2021

The end of the ROK-U.S. missile guidelines opened up the possibility of developing space launch vehicles for various platforms based on air and sea. In particular, the air-based space launch vehicle is an essential space power projection capability compared to the ground-based space launch vehicle in consideration of the geographical location of the Korean Peninsula, such as the deployment of various satellite orbits and the timely launch of satellite. In addition, compared to the ground-based launch vehicle, the cost reduction effect is large, and it has the merit of energy gain because it can be launched with the advantage of the aircraft's altitude and speed. Therefore, in this paper, the necessity of air-based space launch vehicle in the strategic environment of the Korean Peninsula is clearly presented, and through technology trend analysis of various air launch vehicle, the three methods are proposed to have the most efficient air-based space launch vehicle capability in the Korean situation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.115-127
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• 2014

The national Entrepreneurial policy of Start-up assists the young and college students to be raised as entrepreneur in various ways seeking solution for serious unemployment problem. Many young generation start-up a business without prior knowledge and experience in management that end up as a case of failure rather than success. Many young pre-entrepreneur are afraid of Start-up and hesitate or give up before start. Now many Entrepreneurship education contents and Entrepreneurship mentoring programs are being provided for pre-entrepreneur. Especially, Entrepreneurship mentoring programs's importance to ease off these fear and anxiety is recognized and Mentoring program's part and contents are being enhanced in Entrepreneurship education content. In this study, the influence of Entrepreneurship mentoring program to young and brilliant entrepreneur who wants to start a business will be explained. The function of Entrepreneurship mentoring to improvement of entrepreneurial capability will be anaylzed and by using the function of Entrepreneurship mentoring and entrepreneurial capability, the moderating effect of start-up preliminary period and start-up aim period is examined. The results of as regression analysis, the study found out the function of Entrepreneurship mentoring has a positive significant influence with entrepreneurial capability which means technological competence and creativity competence. For the moderating effect of start-up preliminary period and start-up aim period, it is found out that the effect does not have a significant influence on the function of Entrepreneurship mentoring and also technological competence, but on creativity competence, significant influence was found. However, after looking at the moderating effect that is considered to be related to entrepreneurial capability, for the function of mentoring only the effect on start-up preliminary period.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.190-199
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• 2019

South Korea has achieved impressive economic growth relatively quickly by focusing on export-driven policies and economies of scale in the process of industrialization. As the country's economic development policy focused on large corporations, however, a power and wealth imbalance developed between SMEs and large corporations. The purpose of this study is to clarify this issue academically and more clearly through theoretical studies and empirical analysis in order to resolve these imbalances and improve the positive relationship between SMEs and large corporations. To this end, a survey was conducted from December 17, 2018 to January 28, 2019, and a total of 378 questionnaires collected from corporate workers were used for the final analysis. The hypotheses confirmed by the study results were as following. First, the factors directly affecting the competitor's orientation were the trust, entrepreneurship, and innovation capability of the entrepreneurial characteristics. Second, when the characteristics of the company were examined from the perspective of cooperative performance, only the innovation capacity factor had a positive effect. Third, the competitor orientation showed a positive effect on cooperative performance. Fourth, competitor orientation had a statistically significant mediating effect on the relationship between trust, entrepreneurship, innovation capability, and cooperative performance.