• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.316-320
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• 2010

We report an application of full-field optical coherence tomography (FF-OCT) for identifying counterfeit bank notes. The depth-resolved imaging capability of FF-OCT was used for tomographic identification of superficially-identical objects. By retrieving the internal structures of the security feature (cash hologram) of an original banknote, we could demonstrate the feasibility of FF-OCT to identify counterfeit money. The FF-OCT images showed that the hologram consisted of micron scale multi-coated layers including an air gap. Therefore, it is expected that FF-OCT has potential as a new non-invasive tool to discern imitation of currency, and it would find applications in a wide field of counterfeit sciences.

• Journal of Magnetics
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• v.21 no.2
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• pp.239-243
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• 2016

High temperature superconductor (HTS) magnet systems usually employ metal current leads which bridge between the cryogenic environment and room temperature. Such current leads are the dominant heat load for these magnet systems due to a combination of electrical resistance and heat conduction. HTS flux pumps enable large currents to be injected into a HTS magnet circuit without this heat load. We present results from an axial-type HTS mechanically rotating flux pump which employs a ferromagnetic circuit and a Cu-stabilized coated conductor (CC) HTS stator. We show the device can be described by a simple circuit model which was previously used to describe barrel-type flux pumps, where the model comprises an internal resistance due to dynamic resistance and a DC voltage source. Unlike previously reported devices, we show the internal resistance and DC voltage in the flux pump are not exactly proportional to frequency, and we ascribe this to the presence of eddy currents. We also show that this axial-type flux pump has superior current injection capability over barrel-type flux pumps which do not incorporate a magnetic circuit.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.370-375
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• 2006

This paper suggests the method for estimating a partial discharge (PD) location using divide of the inside transformer as a grid. The PD location is found swiftly and economically compared with the typical method detecting a PD. The reason is that the location of PD is detected in the section. The estimation of PD location is trained using the Neural Network. JavaNNS(Java Neural Network Simulator) and SNNS(Stuttgart Neural Network Simulator) are used for searching the location of PD. The simulation procedure is following, The transformer is assumed that the case is a regular hexahedron. The sensor is installed in a proper location. A section of PD location is set as a target, and training set is studied with several PD locations in the inside of the transformer. As a result of training process, the learning capability of neural network is excellent. The PD location is detected by division of internal structure of transformer and application of neural network.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.178-187
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• 2007

One important issue in power systems is dynamic instability due to loosing balance relation between electrical generation and a varying load demand that justifies the necessity of stabilization. Moreover, Power System Stabilizer (PSS) must have capability of producing appropriate stabilizing signals over a wide range of operating conditions and disturbances. To overcome these drawbacks, this paper proposes a new method for robust design of PSS by using an auto-tuning fuzzy control in combination with Real-Coded Genetic Algorithm (RCGA). This method includes two fuzzy controllers; internal fuzzy controller and supervisor fuzzy controller. The supervisor controller tunes the internal one by on-line applying of nonlinear scaling factors to inputs and outputs. The RCGA-based method is used for off-line training of this supervisor controller. The proposed PSS is tested in three operational conditions; nominal load, heavy load, and in the case of fault occurrence in transmission line. The simulation results are provided to compare the proposed PSS with conventional fuzzy PSS and conventional PSS. By evaluating the simulation results, it is shown that the performance and robustness of proposed PSS in different operating conditions is more acceptable

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.3
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• pp.217-232
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• 1999

The ability to see the internal organs of the human body in a noninvasive way is a powerful diagnostic tool of modern medicine. Among these imaging modalities such as X-ray, MRI, and ultrasound. MRI and ultrasound are presenting much less risk of undesirable damage of both patient and examiner. In fact, no deleterious effects have been reported as a result of clinical examination by using MRI and ultrasound diagnostic equipment. As a result. their market volume has been rapidly increased. MRI has a good resolution. but there are a few disadvantages such as high price. non-real-time imaging capability. and expensive diagnostic cost. On the other hand, the ultrasound imaging system has inherently poor resolution as compared with X-ray and MRI. In spite of its poor resolution, the ultrasound diagnostic equipment is lower in price and has an ability of real-time imaging as compared with the others. As a result. the ultrasound imaging system has become general and essential modality for imaging the internal organs of human body. In this review various researches and developments to enhance the resolution of the ultrasound images are explained and future trends of the ultrasound imaging technology are described.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.3 no.4
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• pp.1-41
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• 2008

The Korean semiconductor industry has made a great contribution to growth of Korean economy for the last decades by maintaining a top position in terms of Korean total annual export volume. However, the advanced semiconductor equipment and materials that are used for the production of semiconductor devices still depend on the suppliers from Europe, Japan, and America who have an influential position in the Korean semiconductor industry. The objective of this study is to empirically investigate the attributes determining the extent of autonomy in decision making for the Korean subsidiaries of multinational corporations in the semiconductor industry. This study found there were differences in the extent of autonomy in decision making in terms of the global strategies the multinational corporations pursue. This study surveyed employees at the Korean subsidiaries and joint venture companies of semiconductor multinational corporations and collected 726 survey questionnaires. Several statistical analyses including frequency analysis, reliability analysis, factor analysis, multiple regression analysis and ANOVA were performed using the collected sample data. Based on the analyses, this study found as follows: Firstly, from the factor analysis, this study found Korean subsidiaries faced three sources of uncertainties stemmed from political conditions, competent conditions, demand and supply conditions. The internal resources were characterized by the independencies of production capability, financial capability, marketing capability and human resource management capability. The operational performance was determined by total revenue, net profit and market share growth. Secondly, it was found the uncertainties from political condition and competent condition and the independencies of financial capability and marketing capability partially influenced the extent of autonomy in decision making. The independencies of production capability and human resource management capability significantly influenced the autonomy of decision making in the most areas. It was also found an increase of total revenue, net profit and market share growth partially affected the extent of autonomy in decision making of the Korean subsidiaries. Finally, it was found that the polycentrism of global management by multinational corporations seemed to bring a higher extent of autonomy in decision making than ethnocentrism or geocentrism of global management. Based on the results, this study provided managerial implications regarding the extent of autonomy in decision making for Korean subsidiaries of multinational corporations in order to help management to enhance their business capabilities.

• 한국벤처창업학회:학술대회논문집
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• 2008.11a
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• pp.135-168
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• 2008

The Korean semiconductor industry has made a great contribution to growth of Korean economy for the last decades by maintaining a top position in terms of Korean total annual export volume. However, the advanced semiconductor equipment and materials that are used for the production of semiconductor devices still depend on the suppliers from Europe, Japan, and America who have an influential position in the Korean semiconductor industry. The objective of this study is to empirically investigate the attributes determining the extent of autonomy in decision making for the Korean subsidiaries of multinational corporations in the semiconductor industry. This study found there were differences in the extent of autonomy in decision making in terms of the global strategies the multinational corporations pursue. This study surveyed employees at the Korean subsidiaries and joint venture companies of semiconductor multinational corporations and collected 726 survey questionnaires. Several statistical analyses including frequency analysis, reliability analysis, factor analysis, multiple regression analysis and ANOVA were performed using the collected sample data. Based on the analyses, this study found as follow: Firstly, from the factor analysis, this study found Korean subsidiaries faced three sources of uncertainties stemmed from political conditions, competent conditions, demand and supply conditions. The internal resources were characterized by the independencies of production capability, financial capability, marketing capability and human resource management capability. The operational performance was determined by total revenue, net profit and market share growth. Secondly, it was found the uncertainties from political condition and competent condition and the independencies of financial capability and marketing capability partially influenced the extent of autonomy in decision making. The independencies of production capability and human resource management capability significantly influenced the autonomy of decision making in the most areas. It was also found an increase of total revenue, net profit and market share growth partially affected the extent of autonomy in decision making of the Korean subsidiaries. Finally, it was found that the polycentrism of global management by multinational corporations seemed to bring a higher extent of autonomy in decision making than ethnocentrism or geocentrism of global management. Based on the results, this study provided managerial implications regarding the extent of autonomy in decision making for Korean subsidiaries of multinational corporations in order to help management to enhance their business capabilities.

• 한국벤처창업학회:학술대회논문집
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• 2007.04a
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• pp.203-226
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• 2007

The purpose of this research is to analyze the impact of business scope and technological innovation capability(TIC) on firm performance in SMEs. Among the 1,077 SME sample data collected with the help of Korean Industrial Complex Corporation, 228 sample data from capital goods sectors had been selected and analyzed. Several mutiple regression models were developed to test the main and the interaction effects of two independent variables business scope and TIC on SME performance. The empirical analysis show that the number of product lines, one of the two scope variable measured, is positively correlated with the return on sales(ROS). Among the variable of TIC, the number of intellectual property rights(IPRs) is positively correlated with the sales growth rates of SMEs, which the ratio of engineers to total employees is positively correlated with the ROS of SMEs. The results also delineated some interaction effects of business scope and TIC on SME performance. There exists a positive interaction effect of the ratio of engineers to total employees and the number of product lines both on ROS and scales growth rate. The interaction of the number of customers and the number of IPRs positively effects on ROS, and also the interaction of the number of product lines and the number of IPRs are positively related with ROS. Findings of this research indicates that it is necessary for SMEs in capital goods sectors to accumulate technological innovation capability and to expand business scope to improve firm performance. Furthermore, the accumulation of internal TIC should accommodate with the expansion of business scope to gain an improved performance. Particularly, adequate technological innovation capability is required to address the need of expanded customers when enlarging the scope of customers.

• Journal of Korea Technology Innovation Society
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• v.16 no.3
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• pp.754-783
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• 2013

This study aims to suggest an empirical approach for improving the reliability of the valuation method for the technology developed at universities by using the recent data of university technology transfer. The influencing factors, the internal capabilities of an university and the characteristics of technology area, on the outcome of university technology transfer were investigated for this study. The analysis shows that the technology area distribution of the outcome of technology transfer of each university can be classified into two type: IT and NT area oriented type, and BT and other area oriented type. The analysis also shows that the type of technology area distribution can act as a moderator in the positive relationship between each independent variables, the number of patent applications and the number of technology commercialization staff, and the outcome of technology transfer. Considering that the capability of technology development and that of technology spread are related directly or indirectly to all the technology valuation process, the analysis results imply that the reliability of the valuation method for university technology might be improved by using factors of the internal capabilities of an university and that of the characteristics of technology area.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.101-112
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• 2015

The company's technical reserves in accordance with the internal skills and external technology commercialization capacity and to analyze the impact on the performance of technology commercialization and financial performance of the company. External technology funding, internal and external technologies marketing, internal and external technologies production, outside of the external Technology Commercialization technique was investigated to affect the financial performance. Financing, marketing capability, and the production base is completely mediated effect acting from within the technology business technical achievement, but funding and the regulation of full-mediated effects on the financial performance in the external action, technical marketing skills and capacity of external technology in part mediated effect was investigated by the effect on financial performance.