• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.587-592
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• 2013

In this paper, the performance improvement of the sensorless control of IPMSM employing the active flux concept by the improved current estimator is presented. The accuracy of the current estimator used in a previous report is degraded when the motor parameters are not known exactly. A simple current estimator derived from estimated flux is proposed to improve the position estimation performance. In order to show the usefulness of the proposed estimation method, the simulation results using Matlab/Simulink and the experiment results are presented.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.565-572
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• 2013

The sensorless speed control using the improved full-order flux observer for PMSM is proposed in this paper. A conventional full-order flux observer has a drawback that the estimated flux of this observer contains the ripple component at the low speed range due to the increased gains of the convectional full-order flux observer. The improved full-order flux observer with the modified gains guarantee the improved estimation performance without ripple component at the from zero to high speed range. To identify the performance of proposed observer, the simulation and experiment are conducted and this performance is compared with the conventional full-order observer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.1-5
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• 2008

In this paper, we proposed that when combustible burn with ultraviolet radiation, introduce fire detector with sensor of private-use detectable light energy as ultraviolet in energy of electromagnetic-wave type radiate from flame. This research using ultraviolet flame sensor is pyro-electric ultraviolet sensor based black body radiation theory. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV flame detector and proposed method of false alarm reduced to resemble fire. the result proposed the prevention and extinction of fire technique degree, certificated operation of detector.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.289-293
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• 2004

The sensorless speed control technique for BLDCM using digital IP control is proposed in this paper for advanced speed characteristic which is robust for loads. The sensorless drive of BLDCM using terminal voltages is affected by load or speed because it uses analog filters to estimate the rotor position. For this reason, the robust speed controller with the accurate rotor position estimator is needed for sensorless control which is robust to load and insensitive to motor parameters. The constant speeds robust to load variation and the stable sensorless control of BLDCM robust to the increase or decrease of speed with constant load are implemented using digital IP control in this paper. The validity to these is established with experimentation.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.227-234
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• 2010

When a weapon system is developed, climate elements such as temperature, rainfall, and so on have an effect on development costs and a developing period. Therefore, effects of environment and climate must be examined throughly before the design of weapon systems and be applied to their developments. And so, operational and storage requirements for weapon systems are determined and are applied to related tests through analyzing not only environmental factors such as vibration, shock, and so on, but also climate factors. In this paper, the distribution and the frequency of occurrence of rainfall were analyzed and were suggested as a good guide to determine standards of tests for weapon systems when it's raining.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.826-829
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• 2003

Metal/chalcogenide glass semiconductor(CGS) thin film devices were produced in the vacuum evaporator by the methode of vacuum thermal evaporation. We investigated the influence of the correlations of thickness of metal and CGS upon the concentration of Metal in a CGS thin film. It has shown that M/CGS thin film devices were very sensitive to temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.68-71
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• 1993

In this study, decay time and frquency response characteristics of Self-Integrating Magnetic Sensor were investigated, decay time is 4.4[ms], frequency band that could be measuring is from 40[Hz] to 1[kHz]. The magnetic field components produced by operation of electric machines is measured and analyzed.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.341-343
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• 2009

The Ring Laser Gyroscope makes use of the Sagnac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. The Low Earth Orbit satellite for observatory use require the high accuracy Gyro to control and determine the altitude because of the need of payload pointing accuracy. In this paper, The theory of the Path Length Control is explained. The electrical design of Path Length Controller Is described. The Design for Path Length Controller is composed of the demodulator, integrator, phase shifter, high voltage amplifier. We apply the circuit to 28cm square ring laser gyro and get the test results.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1129-1130
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• 2008

고령사회로 진입함에 따라 보행보조기의 관심이 증가되고있다. 고령자는 로봇의 조작능력이 매우 떨어지기 때문에 외부환경변화(장애물, 위험상황)에 민첩하게 대응할 수 없다. 본 논문에서는 보행보조로봇 사용자가 구동 중 실수를 하더라도 진행하고자 하는 방향의 장애물 대하여 안전하게 회피하는 방법을 제안한다. 보행보로로봇에 레이져 센서를 정면에 장착하여 장애물을 판단하고 로봇이 회피 또는 정지하도록 하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.819-824
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• 2012

This paper presents the wideband vibration system of an electromagnetic vibration energy harvester that obtained electric power for wireless sensor applications from the ever-change vibrations of bridge. It is a system with two degree of freedom vibrations that are composed of two mass and two spring respectively. One system is housing mass and spring, the other is the magnetic mass and spring that is the vibration system construction's element of electromagnetic vibration energy harvester. In other words, it is called dynamic vibration absorber. This paper show that the ratio of housing mass to magnetic mass decides the bandwidth and the size of amplitude of magnetic mass in electromagnetic vibration energy harvester. Therefore, it is necessary to improve the efficiency of energy in electromagnetic vibration energy harvester for wireless sensor applications.