• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.7
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• pp.323-328
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• 2005

This paper is proposed maximum thrust design of slotted permanent magnet linear synchronous motor(PMLSM) using surface harmonic method(SHM) considering slot effect. The genetic a1gorithm is used for optimization. The functional are selected the maximum thrust and the minimum detent force. This time. design parameters are set as permanent magnet(PM) width. PM height and slot width. Thrust is increased from 272[N] to 295[N] and detent force is decreased from 5[N] to 2.43[N] greatly in optimum design. Therefore, thrust ripple isn't generating almost. Also, the results of 2D EMC considering slot-effect are compared with ones of experimental and finite element analysis..

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.39-49
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• 2009

In this paper, we classify web-based social network into two types: open and community, and model user behavior in social activities. After that, we also propose the combination of instant messaging and web system as the method of support asynchronous/synchronous social activities. Furthermore, we introduce ImCoWeb prototype system that supports both asynchronous social activities (ex. social bookmark, comment, rate, and data share) and synchronous ones (ex. real-time communication, file transfer, co-browsing, and co-work). Because it is built on the existing instant messaging, it reduces costs by reusing the facilities such as session management, user management, and security of instant messaging.

• Journal of Power Electronics
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• v.9 no.6
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• pp.940-948
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• 2009

The main objective of this a paper is to improve the efficiency of permanent magnet synchronous motors (PMSMs) by using an improved direct torque control (DTC) strategy. The basic idea behind the proposed strategy is to predict the impact of a small change in the stator flux amplitude at each sampling period to decrease electrical loss before the change is applied. Accordingly, at every sampling time, a voltage vector is predicted and applied to the machine to fulfill the flux change. The motor drive simulations confirm a significant improvement in efficiency as well as a very fast and smooth response under the proposed strategy.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.347-352
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• 2016

This paper investigates the application, design and implementation of unscented Kalman filter observer using the various scaling parameters for the sensorless speed control of a permanent magnet synchronous motor. The principles of unscented transformation and unscented Kalman filter are examined and their applications are explained. Typically the mapping transformation process is divided into two types, namely the basic unscented transformation and the general unscented transformation by virtue of the scaling parameter value. And resultantly, the number of sampling points, weights, code configuration and computation time are different. But there is no little information on the scaling parameter value or how this value influences the system performance. To analyze the unscented transformation with the various scaling parameters in this study, the experimental results under a wide range of operation condition have been demonstrated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.699-704
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• 2007

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.157-159
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• 2007

For a vessel to safely navigate on the ocean, it is required to check the vessel position as frequently as possible. When a vessel navigates oil the ocean or entering/leaving a port, the target area such as islands, points and mountain peak, etc. are used. However, when such target are not available or when vessel navigates in night time, installed artificial navigation aid facilities help successful vessel navigation. Light Wave Aid helps to confirm a position to the navigator directly and quickly. So, the synchronous light to display the accurate signal has wide applications. However, lantern domestic industry is small, and most of the products show non-compatibility. Consequently, this paper presents the synchronous lighting using UTC of GPS, which maintains compatibility with different lanterns. Also, by replacing conventional electric bulb with LED lamp, simple and efficient lighting system is obtained.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.4
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• pp.313-321
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• 2002

A braking algorithm for a PM synchronous motor is presented. The resistance of the stator windings operates as a braking resistors and dissipates the regenerated power from the rotor without any braking components including the electronic power components and control circuits. The proposed braking algorithm maximizes the power dissipation in the stator windings and also generates the maximum braking torque under the limit conditions of DC link capacitor voltage and inverter currents so that it can minimize the braking time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.635-641
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• 2016

In many industrial applications that use the electric motors robust controllers are needed. The method using a neural network in order to design a robust controller when a disturbance occurs is studied. Backpropagation algorithm, which is used in a conventional neural network controller is used in many areas, but when the number of neurons in the input layer, hidden layer and output layer of the neural network increases the processing speed of the learning process is slow. In this paper an adaptive PI(Proportional and Integral) controller based on CTRNN(Continuous Time Recurrent Neural Network) for permanent magnet synchronous motors is presented. By varying the load and the speed the validity of the proposed method is verified through simulation and experiments.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.407-408
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• 2008

This paper presents a synchronous pipeline design for IP-based H.264 decoding system. The first optimization for pipelining aims at efficiently resolving the data dependency due to motion compensation/intra prediction feedback data flow in H.264 decoder. The second one would enhance the efficiency of execution per each pipelining stage to explore the optimized latency and stage number. Thus, the 3 stage pipeline of CAVLD&ITQ|MC/IP&Rec.|DF is obtained to yield the best throughput and implementation. In experiments, it is found that the synchronous pipelined H.264 decoding system, based on existing IPs, could deal with Full HD video at 125.34MHz, in real time.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.170-172
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• 2000

This paper deals with the characteristic analysis of the flux damper with respect to the load, and the stability of Ag/Bi-2223 tapes in a high-Tc superconducting (HTS) synchronous motor. To find out the magnetic field distribution in a detailed model of the actual motor, the experimentally measured currents of the armature and the field windings are used as input parameters. The simulation results show that the flux damper shields the time varying field up to 10%, reduces armature reactance during the motor operation and during load changes, improving the stable motor operation. And it was observed that the flux damper generates loss by means of leakage flux, but this is not significant and it doesn't degrade the performance of the TS synchronous motor.