• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.641-645
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• 2004

This paper presents a new speed control method using the acceleration feedforward compensation and using the disturbance torque estimate method. The proposed method improve transition response characteristic of system and has been a robust characteristic in the four-switch three-phase motor drive system in which the gain of speed controller cannot be made large enough. The simulation results prove the validity of the proposed method.

• 전기전자학회논문지
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• 제22권2호
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• pp.476-479
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• 2018

This paper proposes a method for reducing the amount of current consumption by the transceiver based remote control and the ZigBee RF4CE network layer step. We have studied how to improve power efficiency at short transition time through duty rate management. Also, comparing the measured current consumption before and after the improvement, we confirmed the correlation between the data transmission speed improvement and the current reduction.

• 전기학회논문지
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• 제61권11호
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• pp.1595-1600
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• 2012

This paper shows an improvement of the WRSM (Wound Rotor Synchronous Motor) by satisfying the voltage limit condition at high speed. After that, it compares the performance of the improved WRSM to that of the IPMSM (Interior Permanent Magnet Synchronous Motor). The comparison has been made under the condition where the dimension of the motor is identical to that of the IPMSM, having the rotor switched to a wounded rotor form. Moreover, this paper compares the Basic Model of the two motor, and estimates the parameters of the WRSM, thereby proposing the method to improve high speed performance. Furthermore, this paper presents the feasibility of switching the conventional motor into rare-earth-free motors for traction purpose.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2489-2491
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• 1998

The study of 3D image reconstruction re has developed along the progress of computer. Therfore Great deal of research on it have been done. 3D medical image reconstruction techniques are useful to figure out human's complex 3D structures from the set of 2D section. But 3D medical image reconstruction require a lot of calculation, it takes long time and expensive system. That gives a reason to the improvement of study on speed. In this paper. applying the interpolation to only the part which can appear as cube, I come up with a method that calculates the speed by reducing the a mount of calculation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1146-1148
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• 2007

This paper proposes a method to improve the charging speed and discharging performance of a high voltage capacitor used in a portable medical device. The improvement of the charging speed was achieved by duty cycle control. The discharging performance was carried out by varying the phase duration and the leading edge voltage of the output according to the transthoracic impdedance of the patient. As a result, the improvement in the charging speed and the performance of the discharging parameters shorten the patient treatment time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.2010-2016
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• 2009

Before introducing high speed train, train signal system was operated passively depending on a driver by signal lamp display. Now it is changing to onboard signaling system because of train speed increased(conventional track is 230km/h, high speed track is 380km/h), high speed. low speed freight train operation mixed, operation for high speed train in conventional track and dense operation. ie. ETCS(European Train Control System) Level 1 is introducing. Also, in case of high speed train, the train control system of France was introduced and has operated from 2004, now we have a difficulty for rising speed more than 300km/h because of commercial operation speed limited as 300km/h. Therefore, it need to establish the train control technique according to trackside surroundings and develope standard system like European ERTMS/ETCS, China CTCS(Chinese Train Control System), Japan D-ATC(Digital Automatic Train Control). In this paper, we derive the systematization method for Korea train technique by network-oriented, information-oriented, intelligence-oriented and combination-oriented corresponding train development direction. Proposed method has a merit to prevent cross by mixed operation with existing system and improvement after validity demonstration and system development and supply train system to meet user requirement in exporting.

• Journal of Acupuncture Research
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• 제40권1호
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• pp.44-52
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• 2023

Background: Previous studies have investigated technology-aided needling training systems for acupuncture on phantom models using various measurement techniques. In this study, we developed and validated a vision-based needling training system (noncontact measurement) and compared its training effectiveness with that of the traditional training method. Methods: Needle displacements during manipulation were analyzed using OpenCV to derive three parameters, i.e., needle insertion speed, needle insertion angle (needle tip direction), and needle insertion length. The system was validated in a laboratory setting and a needling training course. The performances of the novices (students) before and after training were compared with the experts. The technology-aided training method was also compared with the traditional training method. Results: Before the training, a significant difference in needle insertion speed was found between experts and novices. After the training, the novices approached the speed of the experts. Both training methods could improve the insertion speed of the novices after 10 training sessions. However, the technology-aided training group already showed improvement after five training sessions. Students and teachers showed positive attitudes toward the system. Conclusion: The results suggest that the technology-aided method using computer vision has similar training effectiveness to the traditional one and can potentially be used to speed up needling training.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.33-38
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• 2012

The wafer positioning robot in the semiconductor industry is required to operate at high speed for the improvement of productivity. The residual vibration caused by the high speed of the wafer positioning robot, however, makes the life of the robot shorter and the cycle time longer. In this study, the input shaping and the path of the system are designed for the reduction of the residual vibration and the improvement of the cycle time. The followings are the process for the reduction and the improvement; 1) System modeling of the wafer positioning robot, 2) Verification of dynamic characteristics of the wafer positioning robot, 3) Input shaping plan using impulse response reiteration, 4) Simulation test using SIMULINK program, 5) Analysis of result.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.356-362
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• 2011

Usually urban railways are built under ground thus the necessary condition of urban railroad, a linear-shaped track, causes a difficulty in enhancement of speed limits of urban rail. Also the underground construction of city railroad produces speed limit values reduced according to a speed code array, in case of speed decision according to the conventional block section division, thus onventionally it could not but apply speed limit values lower than actual safety speeds. In this study, The above two facts induced the author to study on a method to enhance speed limit values for CBTC within existing urban railroad sectors. Since it is possible to exchange data continuously and to control speeds in case of railroads based on CBTC, the author applied result values of speed limits, which were gained based on a railroad condition, a linear track, to the CBTC system without correction of the result values and then the author compared and analyzed, through simulation, the running times and the efficiencies of running energies between railway stations, between the existing fixed-block system and the CBTC system. As a result simulation, the improvement of speed and the deceleration distance of reduction confirmed that it was effective to reduce the time to travel between stations. A fixed block the set of constraints on the speed limit, he way the operation is optimized based CBTC speed limit by suggesting ways to reset the scheduled speed measures to improve were extracted.

• 한국멀티미디어학회논문지
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• 제6권1호
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• pp.105-113
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• 2003

CDMA 셀룰러 시스템 내에서 고속이동체에 대한 비효율적인 채널할당으로 호 블록킹 확률이 높아진다. 이를 위하여 고속이동체의 속도에 따른 전용 채널과 큐를 할당하여 계층셀에 적용해 속도에 따른 QoS를 보장하는 방식이 제안되었다. 본 논문에서는 현재 위치한 셀에서의 이동체의 수신 신호세기에 따라 HA에 트래픽이 적을 때에 FA 내에 고속 핸드오프 전용 채널을 할당하였다 또한 FA 내 신호세기가 약한 고속 핸드오프 호에 대하여 새로운 환형 큐 LiFA를 생성하여 고속 핸드오프 호를 LiFA에 호 지속시간 동안 대기시켜 호 강제종료율을 개선하였다.