• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.12B no.1
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• pp.31-36
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• 2002

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position; therefore, the position of rotor is an essential information. Although optical encoders or resolvers are used to provide the position information, these sensors are expensive. Moreover, in the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. And the control algorithm to generate switching signals using a simple digital logic is presented. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• Asian Journal for Public Opinion Research
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• v.2 no.3
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• pp.140-171
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• 2015

As China's economic development brings the country out of poverty and into modernity, a long-lasting debate concerns whether the Chinese public's value system is also changing toward the so-called "modern values," or whether some distinctly traditional Chinese values remain unchanged. Using empirical data collected at three points in time during the 1990s and the first two decades of the 21st Century (1993, 2002, and 2011), I found that Chinese citizens who benefitted from urbanization, rising levels of education and employment in non-farm, knowledge-based industries displayed stronger modern values. People with stronger modern values are more likely to emphasize individual autonomy, competition, gender equality, and market transaction, among others. Some characteristics of the Chinese people, most importantly family values, however, seem to remain stable amidst rapid social changes.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.67-73
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• 2003

In this paper, the impedance of a piezoelectric transducer is calculated using the three-dimensional finite element method. The validity of numerical routine is confirmed experimentally. Using this numerical routine, the effects of material coefficients on piezoelectric actuators characteristics are analyzed. The material constants, which make significant effects, are selected and the relations between material constants are studied. Using these processes, three variables of material constants for a piezoelectric transducer are selected and the design sensitivity method is adopted as an inversion scheme. The validity of the inversion scheme for a piezoelectric transducer is confirmed by applying the proposed method to the sample piezoelectric transducer.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2043-2055
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• 2014

This paper empirically investigates the effects of technology licensing on the licensee firm's performance with the help of a unique data set of observed licensing transactions in Information and Communication Technology (ICT) industry. We examine how intensity of licensing participation as a licensee affects the firm's performance. This study also analyzes how relationship between the licensor and the licensee in a deal along with characteristics of participants and their industry influences the performance of the licensee firm. The findings suggest that frequent participation in technology licensing increase licensee firm's sales growth. Also, transaction cost considerations and technology spillovers are important explanatory factors that influence licensee firms' performance in licensing.

• Korean Management Science Review
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• v.21 no.2
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• pp.215-234
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• 2004

With enormous changes in market condition, firms try to collaborate with their transaction partners. Recently, the diffusion of the Internet has made it possible for firms to directly collaborate with their partners. Accordingly, the importance of the Collaborative Commerce( C-Commerce) based on the Internet and IT has been emphasized. The literature in relational marketing and strategic alliance, however, has focused on the relational characteristics among firms. Therefore, the fundamental objective of this study is to investigate whether C-Commerce can enhance the positive relationships among firms. Based on theoretical and empirical research, some meaningful discussions can be made. First. the asymmetric commitment between buyers and suppliers decreases the C-Commerce utilization. Second, when specific investment is made to facilitate transactions, firms try to trade efficiently and depend on partners in a long-term period.

• KIEE International Transaction on Systems and Control
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• v.2D no.2
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• pp.53-58
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• 2002

In this paper, various aspects in magnetoencephalography (MEG) source localization are studied. To minimize the errors in experimental data, an approximation technique using a polynomial function is proposed. The simulation shows that the proposed technique yields more accurate results. To improve the convergence characteristics in the optimization algorithm, a hybrid algorithm of evolution strategy and sensitivity analysis is applied to the neuromagnetic inverse problem. The effectiveness of the hybrid algorithm is verified by comparison with conventional algorithms. In addition, an artificial neural network (ANN) is applied to find an initial source location quickly and accurately. The simulation indicates that the proposed technique yields more accurate results effectively.

• International Commerce and Information Review
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• v.9 no.3
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• pp.107-129
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• 2007

In 1990s, both development of internet and digital economy would make new products such as digital goods. Recently, digital goods composed of softwares, digital contents, and digital services have grown up rapidly in the world market. Characteristics of goods and transaction forms in the international trade of digital goods is different from those of traditional goods. Thus, this difference would appear a new risk that did not exist in the international trade of traditional goods. Identification and confirmation about unique export risks of digital goods would be necessary to the increase of export of digital goods needs; however, in spite of the importance, very few studies have been based on the export risks of digital goods particularly in research on the relationships between export risk management and export performance. This study classifies the types of export risks based on the previous studies, and examines the relationship between both management and identification of export risks.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.4
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• pp.159-164
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• 2003

In this paper, a three-dimensional finite element method and construction of equivalent-circuit for a linear ultrasonic motor are presented. The validity of three-dimensional finite element routine in this paper is experimentally confirmed by analyzing impedance of a piezoelectric transducer. Using this confirmed finite element routine, impedance and vibration mode of a linear ultrasonic motor are calculated. Elliptical motion of contact point between vibrator and rail of the linear ultrasonic motor is shown for determination of contact points. By using the finite element method and analytic equations, characteristics of the linear ultrasonic motor, such as thrust force, speed, losses, powers and efficiency, are calculated. The results are confirmed by experiment. Finally, equivalent circuit parameters of the linear ultrasonic motor are obtained using the three-dimensional finite element method and analytic equations.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.214-218
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• 2002

In this paper, the effectiveness of three different control algorithms are thoroughly investigated via simulation and a proposed efficiency evaluation method of experimentation. Both the steady state and transient characteristics of each control algorithm along with its measured efficiency are analyzed. Finally, a novel two-mode maximum power point tracking (MPPT) control algorithm combining the constant voltage control and the incremental conduction (IncCond) methods is proposed to improve the efficiency of the 3KW PV power generation system at different insolation conditions. Experimental results show that the proposed two-mode MPPT control provides excellent performance at less than 30% insolation intensity, covering the whole insolation area without additional hardware circuitry.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.2
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• pp.34-39
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• 2001

This paper described the forces analysis of a hybrid linear pulse motor (HLPM) with high accuracy and repeatability. The HLPM is fed from a phase current by microstepping drive. The finite element method (FEM) is employed for calculating the force. The forces between mover(forcer) and stator(platen) have been calculated using the virtual work method. The detent force, rate of tooth width to tooth pitch and magnetic saturation were analyzed to considered the distortion characteristics of static thrust. The thrust to displacement produced a high pulsating force while the normal force is much higher than the thrust force.