• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1776-1779
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• 2002

In this paper, we measured the heating time on the key measuring point of the meridian of the human body's left and right by using heating machine. Then, based on the fuzzy theory, this study diagnosed the each meridian's strength and weakness, After that, both the strengthening and weakening stimulus of magnetic field was applied to the dominant direction to find out how the degree of strength and weakness of the meridian changed. Ultimately, the magnetic therapy that can stimulate the magnetic field at the time of diagnosis and thereby balancing the interactive of a five system has been materialized. For the stimulation of magnetic field, a stimulating device which can change the direction and time on a specific part of the key measuring points has been developed and used. The therapeutic method is as follows. first, the strength and weakness of the meridian has been determined. Second, both the extremely weak meridian of Yin(Shade) and Yang(Shine), and the extremely strong meridian of Yin and Yang were adjusted by applying appropriate ascending and descending stimuli respectively.

• 노동경제논집
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• 제41권1호
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• pp.83-124
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• 2018

최근까지 우리나라 기업들 내부노동시장에서 임금연공성의 약화, 경력직 채용의 증가, 그리고 교육 훈련의 감소 등 상당히 유의한 변화들이 일어나고 있다는 사실이 통계자료로 확인되고 있다. 이번 연구에서 한국직업능력개발원 "인적자본기업패널" 자료로 기업 내부의 근로자들에 대한 교육 훈련 투자 축소 주요 원인으로 내부노동시장의 약화를 의미하는 정규직 경력직 신규채용비율의 상승 변수의 설명력이 통계적으로 매우 유의하고 강력하다는 점을 발견하고 있다. 전직의 임금손실 가능성도 상당 정도 축소되어온 것으로 나타났다. 내부노동시장의 약화 또는 이완, 그리고 이에 따른 기업 내 교육 훈련의 감소에 대한 대안은 결국 기업외부에 청년층과 중소기업을 위한 현실성 있는 고품질의 인재육성의 사회적 장치들을 구축해나가는 방향이어야 할 것이다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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• pp.211-216
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• 2004

Inductance characteristics, torque variations and ripple according to current, and position of multi-layer buried magnet synchronous machines with field-weakening operations are presented. The rotor structure optimal design of a buried magnet synchronous machine with high performance is investigated, and optimization results and comparison among design candidates are shown. For the fast and accurate search of multiple optima, the auto-tuning niching genetic algorithm is used and a final solution is selected considering various design factors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1473-1479
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• 2011

In this paper, speed control of IPMSM drives for the next generation domestic high speed railway system using multilevel inverter is presented. Multilevel inverter is suitable for the high-voltage high-capacity motor drive system because noise and switching frequency of power semiconductor devices is reduced. For the speed control of IPMSM using multilevel inverter, maximum torque control is applied in a constant torque region, and field weakening control is applied in a constant power region. Simulation programs based on Matlab/Simulink are developed. Finally the designed system is verified by simulation and their characteristics are analyzed by the simulation results.

• 전자공학회논문지B
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• 제33B권6호
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• pp.1-11
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• 1996

The rotor flux level need be changed frequently for field weakening or power efficiency control. Motor inductances depend on rotor flux but not on machine temperature. On the other hand, rotor resistance varies greatly with the machine temperature. Motor parameters such a sinductances and rotor resistance should be known precisely in order to attain high dynamic performance of inductin motor. In this paper, efficient an dnovel identification algorithms for motor inductances and rotor resistance are presented. The rotor flux is changed. As the result, the slip frequency is varied. The identificatin algorithm for rotor resistance measures the varied slip frequency and alters the estimated rotor resistance. Then, the estimated value of rotor resistance will approach its real value. The proposed identification algorithms are computationally simple and have very small identification errors.

• 전기학회논문지
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• 제67권3호
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• pp.391-397
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• 2018

This paper proposes a interpolation error compensation method for PMSM torque control. In PMSM torque control, two dimensions look-up table(2D-LUT) is used for current reference generation due to its stable and robust torque control performance. However, the stored data in 2D-LUT is discreet, it is impossible to store all over the operation range. To reduce the reference generation error in this region, the 2D-Interpolation method is conventionally used, however, this method still remains the error affected by the number of stored data. Besides, in the case stored by fixed unit, this error is increased in field weakening region because of the small number of stored data. In this paper, analyzing the cause of this interpolation error, and compensating the method to reduce this error. Proposed method is verified by the simulation and experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.448-452
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• 2001

This paper describes the nonlinear sensorless control of induction motor by using feedback linearization and current error; the feedback linearization technique and the current error are applied for independent between rotor flux and electric torque and for speed estimation. The dynamic characteristics of the proposed nonlinear control algorithm involving field weakening area are verified by simulation and experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.985-986
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• 2011

This paper deals with d-q axis equivalent circuit analysis of IPMSM(Interior Permanent Magnet Synchronous Motors) considering voltage harmonics. In the field weakening region, as the current vector angle increased, back-emf contains large harmonics, therefore, significant underestimation of voltage or overestimation of speed can be occurred from the conventional d-q axis equivalent circuit analysis. In order to consider the effects of voltage harmonics, a harmonic coefficient is introduced and verified by experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.586-588
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• 2008

농형 유도전동기의 센서리스 벡터제어시 기존의 약계자 알고리즘은 오토튜닝 오차에 의해 자속기준값이 크게 계산되어질 때 역기전력과, 전압제한값에 의해 최대전류를 출력할 수 없다. 본 논문에서는 약계자 영역에서 토크분 전류제어 오차를 이용하여 자속 기준값을 보상함으로써 전류부족에 의한 속도강하를 방지하는 알고리즘을 소개하였고, 시뮬레이션을 통해 그 타당성을 검증하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.794-801
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• 2010

Recently the Korean Government is increasing investment and interest on railway in the transportation field as "low carbon and green growth" policy become main national development strategy. While railway competitiveness is weakening over the road from the inconvenient door-to-door and transfer system of railway, it is meaningful to review excellent railway transfer system of advanced countries and adapt their implications for Korea. Their transfer systems like Japan, Hongkong, France, U.K. and German can be categorized in this research as kinds of transfer & connectivity system and transfer facility & flow planning, and, as a result, their implications can be concluded. Also, analyzing transfer system of Korea's main stations and reviewing the difference between Korea and other countries, this paper suggests main principles and directions of urban planning, alignment of rail line, partnership of project stakeholder in the establishment of transfer system in the railway station in the future.