• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.103-110
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• 2005

Broken rotor bars in induction motors can be detected by monitoring any abnormality of the spectrum amplitudes at certain frequencies in the motor current spectrum. Broken rotor bar fault detection schemes should rely on multiple signatures in order to overcome or reduce the effect of any misinterpretation of the signatures that are obscured by factors such as measurement noises and different load conditions. Multiple Discriminant Analysis (MDA) and Artificial Neural Networks (ANN) provide appropriate environments to develop such fault detection schemes because of their multi-input processing capabilities. This paper describes two fault detection schemes for broken rotor bar fault detection with multiple signature processing, and demonstrates that multiple signature processing is more efficient than single signature processing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.121-123
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• 2001

We synthesized dendrimers containing light switchable units such as azobenzene group at the air/water interface. Their chemical structure was verified by using NMR study and UV spectroscopy. We firstly investigated the monolayer behavior and by light irradiation using $\pi$-A isotherm at the air/water interface. As a result, the monolayer of dendrimer with azobenzene group showed the reversible photo-switching behavior by the isomerization of azobenzene group in their periphery. This suggests that optical behavior and morphological change are affected by the functional group and the symmetric chain.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1689-1693
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• 2003

Communication based train control system is applied regularly worldwide. And this system may be used in domestic soon. Communication based train control system does not depend on conventional track circuit. Therefore, position and distance control of train to prevent collision with leading train may become important safety factor. This paper developed collision avoidance algorithm to control trains of several units efficiently for this. In developing a collision avoidance algorithm, it is desirable to avoid the need for additional system. Additional system restricts the development of the algorithm by limiting the effectiveness of the algorithm to only those areas where the additional system can be afforded and has been installed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.579-582
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• 2002

For train service, safety and reliability is an inevitable performance. Specially, turn-out system of the railway for safety because of actual part. Hence the management is strictly executed over turn-out systems of the railway. Also number of turn-out system need to monitoring systems. In this paper, the data multi-acquisition system for monitoring it is necessary to reduce the cost from the expensive characteristics of multi-monitoring system according to the importance of each data because this system is based on communication of one to several units. We designed the data multi-acquisition system using numbers of micro-controller and the experiment was executed to the actual turn-out system.

• 전기학회논문지
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• 제59권4호
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• pp.733-739
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• 2010

We developed to have an automatic transferring function of a two-motors-driven electrical scooter for women or seniors to use conveniently it since it has been previously to operate it in manual only. The function would be implemented by using master and slave micro-control units(MCU) in the system with the given input and output signals. The simulation and test of the system results show that the transition conditions of either higher accelerating speed and/or higher torque are demonstrated at the worst conditions, which means that the transition points might be set either at the 70% of accelerating speed or from the 100% of load torque. The developed equipment is very useful and has good performance in the real test and would be used for top brand and might be applicable to any other types of green cars.

• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.451-456
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• 2009

Through the development of phasor measurement units (PMU), various aspects of power system dynamic behavior could be monitored and diagnosed. Monitoring dynamic voltage stability has become one of the achievements we can obtain from PMUs. It is very important to select the most appropriate method for the Korea Electric Power Corporation (KEPCO) system since there are many voltage stability indices. In this paper, we propose an advanced WAVI (Wide Area Voltage Stability) that is well suited for the purposes of monitoring the dynamic voltage stability of KEPCO's PMU installation plan. The salient features of the proposed index are: i) it uses only PMU measurements without coupling with EMS data; ii) it is computationally unburdened and can be applied to real-time situations. The proposed index is applied to the KEPCO test system and the results show that it successfully predicts voltage instability through comparative studies.

• 전기학회논문지
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• 제62권8호
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• pp.1074-1079
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• 2013

Demand response(DR) is potential generation alternative to improve the reliability indices of system and load points. However, when demand resources scheduled in DR market fail to reduce demand, it can create new problems associated with maintaining a reliable supply. In this paper, a reliability model of demand resource is constructed considering customers' behaviors in the same form as conventional generation units, where availability and unavailability are associated with the simple two-state model. As a result, the generalized reliability model of demand resources is represented by multi-state model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.155-157
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• 2005

The Electrical Test Bed(ETB) integrates the test environment, required for acceptance tests of system level, prior to FM testing. The ETB will be used for the validation of system-level functions and interface between each subsystem. The FTB supports early functional and limited performance checkout of electrical subsystems. Therefore, it provides the environment for the verification of the Flight Software including AOCS, EPS, and TC&R simulators. These ETB will be composed of engineering version of spacecraft BUS, which are laid on the laboratory table.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1506-1509
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• 1999

This paper presents a new economic dispatch algorithm to improve the unit commitment solution while guaranteeing the near optimal solution without reducing calculation speed. The conventional economic dispatch algorithms have the problem that it is not applicable to the unit commitment formulation due to the frequent on/off state changes of units during the unit commitment calculation. Therefore, piecewise linear iterative method have generally been used for economic dispatch algorithm for unit commitment. In that method, the approximation of the generator cost function makes it hard to obtain the optimal economic dispatch solution. In this case, the solution can be improved by introducing a inverse of the incremental cost function. The proposed method is tested with sample system. The results are compared with the conventional piecewise linear iterative method. It is shown that the proposed algorithm yields more accurate and economical solution without calculation speed reduction.

• 조명전기설비학회논문지
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• 제28권8호
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• pp.47-53
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• 2014

This paper presents an Differential Search(DS) Algorithm for solving the economic load dispatch(ELD) problems with Valve-Point loading constraints. DS algorithm simulates the Brownian-like random-walk movement used by an organism to migrate. Numerical results on a test system consisting of 13 units show that the proposed approach is faster, more robust and powerful than conventional algorithms. Case studies show the simulation results are better than Lagrange method, the Hopfield neural networks and GA.