• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.7
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• pp.313-322
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• 2000

This paper presents optimal placement of minimal set of Phasor Measurement Units (PMU's) and observability analysis of the network with PMU's. In order to find a observable system, a symbolic method which directly assigns an appropriate symbol for measurement or pseudo-measurement to every entry of node-branch incidence matrix is proposed. It is much simpler and easier to analyze the observability of the network with PMU's than the conventional ones. For the optimal PMU placement problem, two approaches which are based on a modified Simulated-Annealing (SA) method and a Direct Combination method are proposed. Some case studies with IEEE sample system are made to show the performance of the proposed methods are almost alike and more effective than the conventional simulated-annealing method. It is also shown that the Direct Combination method is more effective than the modified simulated-annealing one in the sense of computation burden. The results of this study showed also that the accuracy of power system estimation and system observability can be improved the proposed PMU placements.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.197-201
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• 1997

To develop a rapid analytical method of dimethylamine(DMA) and trimethylamine(TMA) in fish, the contents of DMA and TMA in squid(Illex illecebrosus and Sepiell maindroni), cod(Gadus marcrocephalus) and plaice (Paralichthys olivaceus) by gas chromatographic (GC) and colorimetric method were determined. Recoveries for DMA in fish were 86.8~102.5% by GC and 74.2~94.5% by colorimetric method, while those for TMA were 93.0~101.1% by GC and 62.9~117.5% by colorimetric method. The contents of DMA and TMA in fish by GC were 29.7~325.3mg/kg and 145.6~356.0 mg/kg, respectively, and these by colorimetric method were 20.0~241.2mg/kg and 139.1~304.3mg/kg, respectively. The analysis of DMA and TMA in fishes by GC after the solvent extraction was simpler and faster and showed better recovery than colorimetric method.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.341-349
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• 2008

This study proposes new automatic thresholding method, which is important step for detecting binary change/non-change information using satellite images. Result value through pixel-based similarity measurement is calculated cumulatively with regular interval, and thresholding is pointed at the steep slope position. The proposed method is assessed in comparison with expectation-maximization algorithm and coner method using synthetic images, ALI images, and Hyperion images. Throughout the results, we validated that our method can guarantee the similar accuracy with previous algorithms. It is simpler than EM algorithm, and can be applied to the binormal histogram unlike the coner method.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.84-91
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• 2002

A new composite control method for a carriage balancing single inverted pendulum system is proposed and applied to swing up the pendulum and to stabilize it under the state constraint. The target inverted pendulum system has an extremely limited length of the cart(below 16cm). The proposed swing-up controller comprises a sliding mode control algorithm and an optimal control algorithm based on two regions: the region near the inverted unstable equilibrium position and the rest of the state space including the downward stable equilibrium position. The sliding mode controller uses a switching control action to converge along the specified path(hyperplane) derived from energy equation from a state around the path to desired state(standing position). An optimal control method is also used to guarantee the stability at unstable equilibrium position. Compared with the reported controllers, it is simpler and easier to implement. Experimental results are given to show the effectiveness of this controller.

• Journal of Power Electronics
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• v.6 no.4
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• pp.298-306
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• 2006

A high efficiency and low cost sustain driver for a plasma display panel (PDP) utilizing a current pumping method is proposed. The main concept of the proposed circuit is using the current source to charge and discharge the panel. As a result, all power switches can achieve zero voltage switching (ZVS) and every auxiliary switch can also achieve zero current switching (ZCS). Since the inductor current can compensate for the discharge current, the current stress of all the power switches can be reduced considerably. Furthermore, it has features such as a simpler structure, less mass, lower cost, and lower electromagnetic interference than in previous circuits.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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• pp.104-111
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• 1998

This study solves the inverse kinematics problem of industrial FANUC robot. Because every joint angle of FANUC robot is dependent on the position of end-effector and the direction of approach vector, arm metrix T6 is very complicated and each joint angle is a function of other joint angles. Therefore, the inverse kinematics problem can not be solved by conventional methods. Noticing the fact that if one joint angle is known, the other joint angles are calculated by the algebraic methods. $ heta$1 is calculated using neumerical analysis method, and solves inverse kinematics problem. This proposed method, in this study, is more simpler and faster than conventional methods and is very useful in the real-time control of the manipulator.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.5
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• pp.15-20
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• 2012

In this paper, we show new method to find the error locations of received Reed-Solomon code word. New design is much faster and has much simpler logic circuit than the former design method. This optimization was possible by very simplified square/$X^4$ calculating circuit, parallel processing and not using the very complex Divider. The Reed Solomon decoder using this new Chien Machine can be applicated for data protection of almost all digital communication and consumer electronic devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.649-654
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• 2011

In this paper, we show new method to find number of errors in the Reed-Solomon decoder. New design is much faster and has much simpler logic circuit than the former design method. This optimization was possible by very simplified square calculating circuit and parallel processing. The microcontroller of this Reed Solomon decoder can be used for data protection of almost all digital communication and consumer electronic devices.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.180-185
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• 2017

In this research, we proposed the simple and efficient method to calculate the shear stresses by using the mid-point measurements in ${\pm}45^{\circ}$ semiconductor resistor-sensor pair. Compared to the previous works, the measurements became much simpler by combining the approximation theory with the technique of mid-point measurement. In addition, we proposed another novel method for the stress calculation in which we could increase the sensitivity of the stress sensor by controlling the applied voltage between the sensor-pair. For the applied voltage of 8 V, the sensitivity showed a significant increase by 100%.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.125-127
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• 2003

The single phase switched reluctance motor(SRM) is more simpler and robust in the structure than poly phase SRM. It has the merits that it reduces the switching elements and the energy density per volume is very high. Recently, it has been researched and developed in various types and starting method due to the technique of power electronics and the computer added design. The single phase SRM is tried to apply to many industrial appliance field to substitutethe the induction motor by the single phase SRM. On the previous studies, we decided the design parameters of the single phase SRM for the blower driver to adapt the design method of the conventional machine and the poly phase SRM. In this studies, it is proposed the conditions to decide the optimal pole arcs because the stator and rotor pole arcs is very important in the characteristics of the single phase SRM. For this reason, it is analysed the characteristics of current on/off angle vs. pole arc, pole arcs vs. average torque.