• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1401-1403
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• 1995

This paper investigates the light output characteristics of an electrodeless H-discharge lamp. The existing cylindrical fluorescent lamps were wound around with an induction coil of varying size, and were driven by RF power. The light output and the luminous efficacy were measured according to variations of the induction coil gap and the lamp power, respectively. The experimental results show that the luminous efficacy of the lamp is as much as existing electrodeless lamps and the luminous efficacy of lamps are high between 10W and 20W. Theoretical analyses using computer simulation show that the circuit matching is easier in the external coil configuration than in the internal one, and that the current and the power distributions near the coil are shower in t.

• 전기학회논문지
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• 제65권4호
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• pp.561-566
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• 2016

In this paper, effective design method of linear induction motor(LIM) for Maglev is proposed in order to maximize system efficiency of Maglev. For the high system efficiency of Maglev, it is important to minimize weight of traction motor. Light weight design by changing materials of core and winding is conducted without changing volume of LIM. For the silicon steel core of primary part for magnetic flux path, iron-cobalt alloy steel with high magnetic saturation characteristic compared to silicon steel is suggested. Moreover, aluminium winding with light weight instead of copper winding is wounded in the widen slot area due to the high magnetic saturation level. For the verification of performance of proposed model, the characteristics are analyzed by using finite element method(FEM).

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.220-223
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• 2002

본 연구에서는 자체 제작한 2L 규모의 bubble-column photobioreactor에서 H. pluvialis의 배양을 시도하였고 astaxanthin의 축적량 증가를 유도하기 위하여 배양시작 20일 후에 light stress를 주었다. 이 방법을 통하여 대조구에 비하여 68%의 건조균체중량 증가와 215%의 astaxanthin 축적량 증가를 유도할 수가 있었고, bubble-column photobioreactor를 이용한 유도배양이 H. pluvialis의 배양에 적합함을 알 수가 있었다.

• 열처리공학회지
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• 제17권2호
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• pp.73-77
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• 2004

The efforts which increase the strength of the auto-body structure and decrease its weight lead to develop a new concept of part production systems, such as Post-Form Strengthening by induction heat treatment. In this study, several cold and hot-rolled sheet steels were used to find out optimum induction heat treatment conditions. After induction heat treatment, strength of heat-treated sheet steels was increased significantly compared with that of as-rolled steels. From these results, auto-body structure which has more light and safe has been made by using this induction hardening method.

• 전력전자학회논문지
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• 제1권1호
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• pp.27-37
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• 1996

This paper proposes the control algorithm for maximum efficiency drive of PWM inverter - induction motor system with high dynamic performance. If the induction motor is driven under light load with rated magnetizing current, the Iron loss is excessively large compared with the codder loss which results in doer motor efficiency. Maximum efficiency drive of an induction motor can be achieved by controlling the magnetizing current to satisfy the optimal ratio that leads the total motor loss to be a minimum value at a given speed. The proposed control algorithm essentially uses vector control technique and adopts voltage decoupling control strategy to prevent the degradation of dynamic performance due to reduced magnetizing current. To verify the proposed method, digital simulations and experiments are carried out for a squirrel-cage induction motor with the rating of 2.2[kW].

• Plant Biotechnology Reports
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• 제4권2호
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• pp.149-155
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• 2010

Expression of the genes for carotenoid bio-synthesis (crt) is dependent on light, but little is known about the underlying mechanism of light sensing and signalling in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter, Synechocystis). In the present study, we investigated the light-induced increase in the transcript levels of Synechocystis crt genes, including phytoene synthase (crtB), phytoene desaturase (crtP), ${\zeta}$-carotene desaturase (crtQ), and ${\beta}$-carotene hydroxylase (crtR), during a darkto-light transition period. During the dark-to-light shift, the increase in the crt transcript levels was not affected by mutations in cyanobacterial photoreceptors, such as phytochromes (cph1, cph2 and cph3) and a cryptochrome-type photoreceptor (ccry), or respiratory electron transport components NDH and Cyd/CtaI. However, treatment with photosynthetic electron transport inhibitors significantly diminished the accumulation of crt gene transcripts. Therefore, the light induction of the Synechocystis crt gene expression is most likely mediated by photosynthetic electron transport rather than by cyanobacterial photoreceptors during the dark-to-light transition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.674-679
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• 2000

Designing of the squirrel cage AC Traction Motor has many difficulties which has to be small size in order to be suitable into bogie frame, high efficiency and light weight. It means that induction motor for tractive purpose has to be different magnetic and electric loading ratio from industrial induction motor. This paper is devoted to an examination of how this ratio affects overall design concept and hence the main design points for traction motor. Also studied is tile changed coefficients of the magnetic and electric loading ratio squirrel cage induction motor for the traction purpose which has been already identified from tile reference book for industrial purpose induction motor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.702-704
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• 2000

Designing of the squirrel cage AC Traction Motor has many difficulties which has to be small shape in order to be suitable into bogie frame, high efficiency and light weight. It means that induction motor for tractive efforts has to be different magnetic and electric loading ratio from industrial induction motor. This paper is devoted to an examination of how this ratio affects overall design concept and. hence the main design points for traction motor. Also studied is the changed coefficients of the magnetic and electric loading ratio squirrel cage induction motor for the traction purpose, which has been already identified from the referance book for industrial purpose induction motor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권6호
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• pp.402-408
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• 2004

This paper proposes the novel V/f control method to improve the stability of a V/f controlled induction motor drive system. The conventional V/f control method used in the proposed V/f control method is a vector-based method that is slightly different from the existing conventional V/f control method. The proposed control method uses a dynamic current compensator to improve the stability of a V/f controlled induction motor drive system. This proposed method is easy to implement and completely eliminates the motor oscillation phenomenon causing the instability of a V/f controlled induction motor drive system, especially when the system is driven near the resonant frequency in steady-state with light load. Additionally, this paper analyzes theoretically the instability of a V/f controlled induction motor drive system and shows the validity of the Proposed V/f control method through simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.352-354
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• 2000

The induction motor is a high-efficiency machine when working close to its rated operation point. This paper uses a simple induction motor model that includes iron losses. The model, which only requires the knowledge of conventional induction motor parameters, is referred to a field-oriented frame. At steady-state light-load condition the minimum point of the input power can be found with the condition that it is possible to obtain the same torque with different combinations of flux and current values. Using the minimum point. the drive system with the proposed efficiency optimization controller can be controlled easily. Simulation and experimental results show the effectiveness of the control strategy proposed for an induction motor drive.