• Journal of Korean Society for Quality Management
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• v.38 no.2
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• pp.261-275
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• 2010

The purpose of this study is to empirically analyze the productivity change of the 10 Single PPM Certification Company in the 3 Industry(Electronics, Motor-Parts, Machines). In this study, Productivity change over the time in Korean small and medium sized firms in the 3 industries by the bootstrapped Malmquist Productivity Index(MPI). The traditional Malmquist Productivity Index(MPI) and Data Envelopment Analysis(DEA) Models have not only bias but also lack statistical confidence intervals. they could lead to wrong evaluations of the efficiency and productivity scores. In this paper, DEA and a MPI are combined with a bootstrap method in order to provide statistical inferences that analyze the performance of the Single PPM Certification Company. The data cover the period between 2004 and 2007. The result of this paper reveals : 1) The Electronics Industry had productivity effect of 17%, but there was not direct effect for other Industries(Motor-Parts, Machines). 2) average productivity Progress of the 7DMU(Electronics), 1DMU(Motor-Parts) and none(Machines).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.411-418
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• 2016

In accordance with global energy conservation policies such as MEPS(Minimum Energy Performance Standard), electric motor industry is moving to super-high-efficiency machines and research to develop IE4 (International Energy Efficiency Class4) motors has been launched. In this situation, SynRM (Synchronous Reluctance Motor) has been attracting attention in place of induction motor which hardly provides super premium efficiency. As a result, much research on SynRM is being performed at home and abroad. Also, some products have already been appearing in the market. Compared to induction motor, SynRM has better efficiency per unit area and wider operating range. Although the utilization of control system in synchronous motor results in higher prices, we still need to concentrate on developments of SynRM so as to comply with the new policies. This study demonstrated the electromagnetic design methods of super-premium SynRM while maintaining the frame of existing IE3 induction motor for blower. We documented the design procedures for generating high saliency which is the most essential and mechanical stress analysis is also treated. In conclusion, we proved the validity of our design by manufacturing and testing our SynRM models.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.146-148
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• 2002

An automatic inspection vision systems whose development was the industry applications motor rear side member. This system are connected to the 9 ea camera fur the process inspection the bolt, nuts, units in the rear side member product. This automatic inspection vision systems can perform inspection of not attached the bolt, nuts, units, etc fast and accuracy in react time fashion. And then perform very sophisticated inspection which human workers can not perform.

• Proceedings of the Safety Management and Science Conference
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• 2007.11a
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• pp.457-461
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• 2007

This study presents service quality systems such as automobile industry insurance, personal accident insurance service vehicle repair and tow services, and, the service for buying and selling of used motor vehicles. These service quality systems include contracting services, payment service, infrastructure, adjustment service, and, process.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.854-861
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• 1988

The current source inverter-fed induction motor(CSIM) drive is widely used in industry because of its four quadrant operation, fuseless protection, fuseless protection, and ruggedness. the CSIM drive system, however, has shortcomins such as slow response and dynamic stability to load torque disturbance and reference speed change. Such a disadvantages can be compensated considerably by means of introducing additional angle angle control loop. The angle control method is dependent upon the inverter type. In this paper, simultaneus recovery and commutation inverter(SRCI) which is developed recently is considered.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.43-45
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• 2005

A High precision position control technique is used in many kind of industry areas. Especially this is to be one of the important parts in the development of precision machines. To get high precision and long range, dual servo voice coil motor(VCM) has been designed and implemented. In this paper, as a simulation and experimental result, the developed dual servo VCM shows the applicable possibility for precision machine system.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1253-1264
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• 2016

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.97.1-97.1
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• 2008

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.16-22
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• 2005

It is difficult to separate those of NC controller from the error of machine tools because the conventional testing methods to inspect the performance are including the errors of moving system, therefore it has been used as the methods that compare the other controllers. Also, it is hard to predict the machine itself errors with the methods assembling the NC controller and moving system on machine because of the variable load conditions. In this study, the performance inspecting system was developed by analyse the $axis\_rotating$ properties of servo system finally outputting from NC controller. The axis torque was controlled by motor dynamometer and the rotating position accuracy was measured by this developed system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.12
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• pp.616-623
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• 2003

Conventional P/PI speed controller of today's servo drives should be manually tuned the controller switching set-point by trial-and-errors, which may translate the drive system down-time and loss of productivity. The adjustable drive performance is heavily dependent on the quality of the expert knowledge and becomes inadequate in applications where the operating conditions change in a wide range, i.e., tracking command, acceleration/deceleration time, and load disturbances. In this paper, the demands on simple controls/setup are discussed for industry servo drives. Analyzing the frequency content of motor torque command, P/PI control mode switching is automatically performed with some prior knowledge of the mechanical dynamics. The dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time over the whole operating conditions. For comprehensive comparison of traditional P/PI control scheme, extensive test is carried out on actual servo system.