• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.338-343
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• 2005

Pb(Zr,Ti)O₃[PZT] thin films were prepared on a highly (100) oriented LaNiO₃[LNO] and a randomly oriented LNO by sol-gel process. The PZT thin films on a highly (100) oriented LNO show a high (100) crystal orientation (F=100 ％), those on a randomly oriented LNO show a random crystal orientation (F=60 ％). All the PZT layer have a flat and dense microstructure with large columnar grains and their grain size are 25 nm. In the ferroelectric curves at electric field of 40 kV/cm, a highly (100) oriented PZT/LNO samples show coercive field, E/sub c/=10 kV/cm and remanent polarization, P/sub r/=14.5 μC/㎠, while a randomly oriented PZT/LNO sample show E/sub c/=10 kV/cm and P/sub r/=5.4 μC/㎠.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.696-698
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• 2004

In this paper we design $H_{\infty}$ infinity controller for Induction motor with low speed operation. $H_{\infty}$ controller is applied in order to design a state feedback static controller for field oriented control of an induction motor. $H_{\infty}$ controller are linear plant can be set up using the same assumptions that are at the basis of field oriented control. Thus, $H_{\infty}$ control theory can be successfully used to set up a state feedback controller for field oriented control of an induction motor. The performances of the $H_{\infty}$ controller is numerically analysed and experimentally verified to prove the validity of the design procedure. In this paper show that performances with high robustness to variations of system parameter.

• 전력전자학회논문지
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• 제3권2호
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• pp.125-130
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• 1998

본 논문에서는 유도전동기 자속기준제어에 필요한 회전자 자속각 연산을 위한 새로운 자속 연산기를 제시한다. 순수 적분기로 구성된 자속연산기를 사용하여 전압, 전류 정보로부터 실제 회전자 자속을 추정하였다. 제안된 자속 연산기에서는 순수 적분기의 드리프트(drift) 문제를 해결하기 위한 새로운 보상 방법을 도입하였으며, 전동기 속도는 추정된 자속각과 추정된 슬립 주파수로부터 연산하였다. 제안된 방법의 성능을 실험을 통하여 입증하였다. 제안된 시스템의 정경속도의 1/100 이하에서도 안정되게 운전되는 것을 실험결과로부터 확인하였다.

• 복식문화연구
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• 제12권2호
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• pp.239-248
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• 2004

This study was examined the characteristics of individual or an organization differences of oriented value and shared value for the employees in the field and management division of clothing enterprises in Korea. The hypothesis of this study are as follows: ＜Hypothesis 1＞ The field employees of clothing enterprise would prefer to have a professional tendency and the management employees would prefer to have the organizational tendency. ＜Hypothesis 2＞ The employees who have organizational tendency would have higher shared standard of organization value than the employees of professional tendency. As a result of the study, the hypothesis 1 has accepted as showing the mean value is high when the field employees have their professional tendencies and the management employees also have their organizational tendencies respectively. The hypothesis 2 has also accepted that the employees who have organizational tendency have higher shared value than the employees of professional tendency.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.185-191
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• 2004

This study describes the scheme of vector drive system without speed sensor for AC servo motor using theory of a flux observer and based on the field oriented vector control. The new method of speed estimation is presented from operate with the position and magnitude of the secondary flux which obtain from the voltage reference and detected current. As the estimated speed is settled by the flux and the machine-specific parameters. this method don't need to adjust the gain of the parameter. Based on the derived theory for vector control. the scheme for sensorless vector drive of AC servo motor is designed and realized. And the experiment verifies it passable to realize the sensorless vector drive based on a field-oriented type.

• 대한전기학회논문지
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• 제36권4호
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• pp.267-272
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• 1987

In this paper, field oriented control is applied to a 16 bit micro-processor Mc68000 controlled CSI fed induction motor servo drive. The control of induction motor using the principle of its is able to have the transient performance nearly to that of DC motors in the position control. The software and hardware for the Mc68000 is developed. The position control scheme consists of the field oriented control loop and te speed reference pattern generator. The digital computer simlation and experimental results are provided, close agreement between them is obtained.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.118-123
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• 2010

The selection of flux level in the maximum torque control of stator flux-oriented induction motor drives in the field weakening region is dependent on stator resistance and inductances. This paper presents parameter detuning effects of stator flux-oriented control drives in the field weakening region. The detuning effects of stator resistance and rotor leakage inductance are analyzed. The decrease of torque and the flux control lost by the detuning of inductance are shown in the simulation results.

• Journal of Power Electronics
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• 제12권6호
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• pp.982-991
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• 2012

In this study, a new method has been presented for the detection of broken rotor bar (BRB) faults in inverter driven induction motors controlled via Field Oriented Control (FOC). To this end, a FOC controlled induction motor with a BRB fault was modeled using the Matlab/Simulink program. Experiments were carried out using the prepared simulation model at various loads and operating speeds. The motor current and speeds were monitored for healthy, 1, 2 and 3 BRB faults. The Resampling Based Order Tracking Analysis (RB-OTA) method was applied to the monitored signals. The obtained results were compared by using the classic Fast Fourier Transform (FFT) method. When the obtained results were analyzed via the FFT method no information regarding any faults was determined in the run up or run down regions of the motor and the presented method gave very good results. The reliability of the proposed method was validated with experimental results. The main innovative part of this study is that the RB-OTA method was implemented on the induction motor current signal for detecting BRB faults.

• 실천공학교육논문지
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• 제9권1호
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• pp.1-5
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• 2017

대학의 고등직업교육 중심기관으로서 역할을 다하여 노동시장의 미스매치 현상과 이로 인한 기업의 신입사원에 대한 재 교육비 소요 등의 불만 요소를 해소하는 노력이 필요하다. 이러한 산업사회의 수요에 대응하는 인력개발요구 및 기계분야 산업현장 요구를 충족시키는 교육과정에 있어서 제안된 능력단위를 근거로 해서 실무형 교육과정을 개발하는 사례를 소개하고자 한다. 산업체 직무를 분석하여 영역별 요구 수준을 파악한 후, 새로운 교육과정을 개발하고, 이에 따라 전문기술인력으로 갖추어야 할 능력과 높은 성과를 창출할 수 있는 인력양성의 중요성이 증대되고, 이러한 현장중심의 교육과정 개발을 통하여 재학생들의 취업률 향상에도 많은 도움이 될 것이다.

• 한국실천공학교육학회논문지
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• 제1권1호
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• pp.79-84
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• 2009

산업기술 변화에 능동적으로 대처할 수 있는 현장중심의 공학교육을 위해서는 현장경험이 풍부한 강사, 교재, 교육콘텐츠와 더불어 현장과 연계된 교육장비의 활용이 반드시 필요하다. 기존의 교육장비는 현장중심이 아닌 해당 기술을 쉽고 편리하게 교육하기 위한 보편적인 장비가 주류를 이루고 있다. 이는 산업기술 변화에 따라 관련 공학교육이 뒷받침되고 있지 못하고 현장교육과 점점 멀어져가는 이유이다. 이에 본 논문에서는 공학교육에 있어서 중요한 역할을 하고 있는 교육훈련 장비의 개발사례를 살펴보고 이들 장비를 실제 교육에 활용하였을 때의 만족도 조사를 분석하여 향후 현장중심의 공학교육에 적합한 교육장비 개발 및 활용 방안을 제시하고자 한다.