• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.397-402
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• 2005

A new control algorithm of soft starter is proposed for the reduction of the inrush current during the grid connection of the induction-type wind power generator. Currently, the fixed speed wind turbine using induction generator is the most popular wind generation system in Korea. It is shown that the amount of inrush current mainly depends on the control algorithm of the soft starter, a thyristor-based grid connection device. For the simulation study, a 600kw wind turbine simulation model is developed and the transient waveforms are investigated with conventional md proposed methods. Also experimental results using 3.7kW experimental set-up show that the peak value of inrush current is reduced about 20$\%$ using proposed algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.496-503
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• 2003

SFC system has come to be used as drive large synchronous machine in many industry applications. Many papers have been presented on the control algorithm of SFC system, not the acceleration and start-up but the rated speed operation with line connection and the braking operation with regeneration which is used in the industry. This paper presents the whole section control algorithm for a large synchronous machine using SFC system. The results of experiment show that the proposed algorithm is proper and effective.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.847-849
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• 2009

Usually, after the decisions of the performance and range in the commercial vehicle, it is designed the ratings of the electric and mechanical elements for the vehicles. In this paper, the given performance and driving conditions, which are the maximum velocity, mileage, total weight of the normal gasoline scooter, battery type and size, and so on, are analysed for the design of the electric scooter. The maximum rotational speed and needed torque values of the electric motor which is substituted for the gasoline engine are calculated. These values can help to calculate the rating of the electric motor. In the calculation to obtain the torque and speed values, battery discharge and the running resistances are considered. We can decide the electric motor current value from the torque and speed values. The electric motor current values, which are significant parameter to decide the motor type and dimensions and characteristics of the electric motor, are decided by numerical simulation by the above conditions.

• Science of Emotion and Sensibility
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• v.23 no.2
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• pp.103-120
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• 2020

Using driving simulation, this study investigated the effects of driver's trust in the adaptive cruise control (ACC) system and road density on driver's workload and situation awareness. The drivers were allocated into one of four experimental conditions manipulated by ACC system trust level (trust-increased vs. trust-decreased) and road congestion (high vs. low). The workload and situational awareness of the participants were measured as dependent variables. The results showed followings. First, trust-decreased group for the ACC system had significantly lower trust scores for the system in all of the measurement items, including reducing the driving load and securing safe driving due to the use of this system, than the trust-increased group. Second, the trust-decreased group showed a slower reaction time in the secondary tasks and higher subjective workload than trust-increased group. Third, in contrast, the situational awareness for the driving situation was significantly higher in the trust-decreased group than trust-increased group. The results of this study showed that the driver's trust in the ACC system can affect the various information processing performed while driving. Also, these results suggest that trust in the user's system should be considered as an important variable in the design of an automated driving assistance system.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.51-57
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• 2002

The purpose of the study was to measure and compare driver's psychophysiological responses in different driving conditions through driving simulator. Twelve male adults(more than 1 year of driving experience) were assigned to four different driving conditions, such as normal speed(70㎞/h), sudden start(0㎞/h→70㎞/h), and sudden stop(70㎞/h→0㎞/h), and their simulator sickness, subjective pleasantness and arousal, EEG, ECG, skin temperature, and GSR were measured. Subjective and physiological evaluations were executed before and after driving in each condition. The results showed that subjective pleasantness and arousal increased in sudden stop and sudden start conditions, relative to stop and normal speed conditions. As the central nervous responses, beta wave increased and alpha wave decreased in sudden stop and sudden start conditions, relative to stop and normal speed conditions. With regard to the autonomic responses, heart rate and GSR increased, while skin temperature decreased in sudden stop and sudden start conditions, which means an activation of sympathetic nervous system. The results suggested that based upon observation of the distinctive psychophysiological changes by driving conditions, it is possible to evaluate the human sensibility in dynamic environment.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1105-1106
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• 2011

본 논문에서는 EV 구동용 유도전동기와 매입형 영구자석 동기전동기(IPMSM)의 동작특성과 효율을 비교하기 위하여 농형구조 유도전동기와 단층구조 IPMSM을 설계 하였다. EV 구동용 전동기는 정속운전 뿐만 아니라 가변속 운전이 필수적이므로 유도전동기는 V/f 제어, IPMSM은 약계자 제어를 사용하여 가변속 상태에서의 운전토크와 효율을 유한요소법을 이용하여 해석하였다.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.91-94
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• 2002

SFFS(Solid Freeform Fabrication System) is commercializing to rapid prototyping concept in foreign some corporations including the U.S.A, have much technological problems yet and need new mode for agile prototyping. In this paper, we design algorithm that the cutting path of laser beam, on the SFFS(Solid Freeform Fabrication System), is controlled with constant speed. The designed algorithm for constant-speed path control is implemented and experimented in the CAFL$\^$VM/ (Computer Aided Fabrication of Lamination for Various Material) system, the new SFFS which was developed in this paper.

• Journal of Korea Ship Safrty Technology Authority
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• v.6
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• pp.76-84
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• 2001

수중익선과 같은 고속선의 경우 수중익이 수면근처에 접근하면 여러형태의 파를 유기하게 되며 그에 의한 압력의 변화를 유발시킨다. 이에따라 양력이 감소하고 조파저항이 증가하다가 한계 Froude 수에 이르게 되면 파가 더이상 자신의 형태를 유지하지 못하고 부서지는 쇄파가 발생하면서 조파저항은 감소하고 그대신 쇄파저항이 급격히 증가하게 된다. 이에대한 연구의 한 방법으로 수면하에서 정속으로 움직이는 수중익에 의하여 생성되는 정상파 및 쇄파현상에 대한 연구를 회류수조에서 수행하였다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.72-80
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• 1997

본 논문에서는 공동주택의 고가수조방식 급수설비에 전동기의 운전패턴과 수조의 밸브 개방 패턴을 변화시켜 전동기의 운전효율을 향상시킬 수 있는 운전제어 기법을 제안하였다. 제안된 운전제어 기법의 유용성을 확인하기 위하여 모의 실험을 통하여 제안된 운전제어 기법과 기존의 제어방법을 비교분석 하였다. 그 결과, 기동횟수와 정속 운전시간 측면에서 우수함을 확인할 수 있었다. 이 운전제어기법을 현장에 적용한다면 전동기 운전효율 향상과 유지보수 측면에서 활용될 수 있을 것이다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.69-77
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• 1991

A collision-free trajectory planning algorithm using an iterative learning concept is proposed for dual robot arms in a 3-D common workspace to accurately follow their specified paths with constant velocities. Specifically, a collision-free trajectory minimizing the trajectory error is obtained first by employing the linear programming technique. Then the total operating time is iteratively adjusted based on the maximum trajectory error of the previous iteration so that the collision-free trajectory has no deviation from the specified path and also that the operating time is near-minimal. To show the validity of the proposed algorithm, a numerical example is presented based on two planar robots.