• 전기학회논문지
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• 제56권12호
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• pp.2150-2156
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• 2007

According as level of industry develops day after day, electricity load system of industry requires high level control, effectiveness and high efficiency. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting and electric heating system. But, problems that power factor deterioration and fast response of control, efficiency, harmonics and etc are still remain. Therefore, in this paper proposed an inverter systems with constant current regulation and power factor correction (PFC) circuit for lighting and beaconing of aerodromes. The effectiveness of the proposed system confirmed through experimental results of 10[kW] power supply system.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1311-1318
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• 2015

This paper introduces a novel topology and an effective control strategy for a shunt hybrid power filter (SHPF) to simultaneously compensate harmonic currents and reactive power. The proposed SHPF topology is composed of an LC passive filter tuned to the 7^th harmonic frequency and a small-rated active filter connected in parallel with the inductor L_pf of the LC passive filter. Together with the SHPF topology, we also propose a control strategy, which consists of a proportional-integral (PI) controller for DC-link voltage regulation and a PI plus repetitive current controller, in order to compensate both the harmonic current and the reactive power without the need for additional hardware. Thanks to the effectiveness of the proposed control scheme, the supply current is sufficiently compensated to be sinusoidal and in-phase with the supply voltage, regardless of the distorted and phase lagging of the load current. The effectiveness of the proposed SHPF topology and control strategy is verified by simulated and experimental results.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.494-497
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• 2002

본 논문에서는 동적신경회로망을 이용한 미지의 비선형 시스템 제어 방식을 제안하였다. 제안한 방식은 비선형 시스템의 상태 공간 모델과 유사한 형태의 신경회로망을 구성하여 비선형 시스템을 식별하고, 식별한 정보를 이용하여 제어기를 설계하는 방식이다. 제안한 방식의 유용성을 확인하기 위하여 단일 관절 매니퓰레이터를 대상으로 시뮬레이션을 수행한 결과 우수한 제어 성능을 확인하였다.

• 한국정밀공학회지
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• 제14권5호
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• pp.108-117
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• 1997

To prove the stability and the effectiveness of the robust non-linear friction control suggested and proved analytically in the previous paper, the describing function analysis is introduced. The instability of the Southward's nonlinear friction compensation for a digital position control and the improvement of phase margin of the robust nonlinear friction compensation are verified qualitatively through the describing function analysis. Those controls are applied to a single-axis digital servo driving experimental setup which has inherent stick-slip friction and experimental results confirm the results obtained in and the effectiveness of the robust nonlinear friction compensation for a digital position control.

• 유통과학연구
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• 제19권10호
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• pp.65-74
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• 2021

Purpose: The purpose of this study is to identify the maximum organizational effectiveness of compensation systems in the distribution industry. It is to identify the relationship between structural compensation and organizational effectiveness. It also aims to clarify whether distributive justice plays as a controlling variable between two variables. Research design, data and methodology: This study was conducted on distribution industry employees. The questionnaire was collected through self-subscription. A total of 209 questionnaires were collected during the month of April 2021, of which 203 were used as valid samples. Results: Structural compensation have been shown to have a positive impact on two sub-factors of organizational effectiveness. In the verification of the controlling effect of distributive justice, perceived fairness has a control effect on the relationship between extrinsic compensation and organizational effectiveness but it does not show a controlling effect on the relationship between intrinsic compensation and organizational effectiveness. Conclusions: Structural compensation has a positive effect on organizational effectiveness. The distribution industry should aware of the compensation and the perceived fairness. The fairness of distribution plays a role in identifying the recognition of compensation and organizational feasibility, identifying motivations of employees, and mediating proper strategies to enhance job satisfaction.

• Journal of Power Electronics
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• 제10권5호
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• pp.505-517
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• 2010

In this paper, an intelligent sliding-mode speed controller for achieving favorable decoupling control and high precision speed tracking performance of permanent-magnet synchronous motor (PMSM) drives is proposed. The intelligent controller consists of a sliding-mode controller (SMC) in the speed feed-back loop in addition to an on-line trained wavelet-neural-network controller (WNNC) connected in parallel with the SMC to construct a robust wavelet-neural-network controller (RWNNC). The RWNNC combines the merits of a SMC with the robust characteristics and a WNNC, which combines artificial neural networks for their online learning ability and wavelet decomposition for its identification ability. Theoretical analyses of both SMC and WNNC speed controllers are developed. The WNN is utilized to predict the uncertain system dynamics to relax the requirement of uncertainty bound in the design of a SMC. A computer simulation is developed to demonstrate the effectiveness of the proposed intelligent sliding mode speed controller. An experimental system is established to verify the effectiveness of the proposed control system. All of the control algorithms are implemented on a TMS320C31 DSP-based control computer. The simulated and experimental results confirm that the proposed RWNNC grants robust performance and precise response regardless of load disturbances and PMSM parameter uncertainties.

• Journal of Mechanical Science and Technology
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• 제15권8호
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• pp.1097-1107
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• 2001

In this paper, the wall following navigation algorithm of the mobile robot using a mono vision system is described. The key points of the mobile robot navigation system are effective acquisition of the environmental information and fast recognition of the robot position. Also, from this information, the mobile robot should be appropriately controlled to follow a desired path. For the recognition of the relative position and orientation of the robot to the wall, the features of the corridor structure are extracted using the mono vision system, then the relative position, the offset distance and steering angle of the robot from the wall, is derived for a simple corridor geometry. For the alleviation of the computation burden of the image processing, the Kalman filter is used to reduce search region in the image space for line detection. Next, the robot is controlled by this information to follow the desired path. The wall following control scheme by the PD control scheme is composed of two control parts, the approaching control and the orientation control, and each control is performed by steering and forward-driving motion of the robot. To verify the effectiveness of the proposed algorithm, the real time navigation experiments are performed. Through the result of the experiments, the effectiveness and flexibility of the suggested algorithm are verified in comparison with a pure encoder-guided mobile robot navigation system.

• 보건교육건강증진학회지
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• 제28권2호
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• pp.41-50
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• 2011

Objectives: Objectives: The objective of this study is to describe the WHO-CHOICE(World Health Organization- CHOosing Interventions that are Cost-Effective) programme, and to consider the application of WHO-CHOICE programme in Korea, especially on the health promotion policy. Methods: Literature review was conducted on the contents of WHO-CHOICE programme in the previous studies, guidebook, and software. We also contacted WHO-CHOICE team at WHO to identify the contents not clearly presented in the documents. Results: The WHO-CHOICE programme is a standardized tool for analyzing and comparing the cost effectiveness of health promotion policies. It is composed of PopMod to measure the health effect of intervention and of CostIt to measure the cost. The cost of tobacco control policy in Korea was analyzed with the cooperation of WHO-CHOICE team preliminary, and the results were different with the results of tobacco control policy on western pacific region of WHO. Conclusions: The cost effectiveness study based on WHO-CHOICE programme could help decide a priority of health promotion policy for settings with limited resources. For the improvement of health, the future work on WHO-CHOICE programme need to be considered.

• 한국과학교육학회지
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• 제14권3호
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• pp.285-292
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• 1994

The purpose of this study is to investigate the misconception about circulatory / excretional system and to determine the effectiveness of two teaching strategies. The subject was 214 middle school students. The control group was instructed with the traditional teaching method.On the other hand, the experimental group was taught with the concept mapping teaching method. Then the effectiveness of the two teaching strategies were compared in terms with the changes of their conceptions about circulatory/excertional system. The major findings of this study are as follows. 1. The major misconception types were identified. 1) The function of blood is only transportation. 2) The artery is equal to arterial blood. 3) The colon and the anus are also excretional organs. 4) Urine is formed from the bladder. 5) Urine and feces are also excrement. 2. Different conceptional change was observed between control group and experimental group at 0.05 significance level. The concept mapping strategy was more effective than traditional teaching method. 3. No significent difference was found between male and female students in the effectiveness of concept mapping strategy.

• 성인간호학회지
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• 제21권2호
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• pp.155-166
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• 2009

Purpose: This study developed and evaluated a systematic intervention among medical ICU nurses for preventing ventilator-associated pneumonia (hereafter VAP). Methods: A VAP prevention program was proposed based on a literature review, revised to fit the target situation, and validated. It was composed of one-time interventions including education, pamphlets, hand cultures, and a quiz event, as well as repeated interventions such as posters, reminders, posting hand culture results, and performance feedback. A simulated control group pretest-posttest design was used to verify the effectiveness of the VAP control program. The incidence of VAP among ICU patients was measured both during 3 months before (n=80) and during 3 months after (n=75) intervention. Results: The VAP prevention program's effectiveness, with a pre-intervention VAP rate of 17.38 and post-intervention rate of 11.04 per 1,000 ventilator days, showed a clinical tendency to decrease, but the difference was not statistically significant (p=.750). Conclusion: A VAP prevention program of multiple interventions can be useful in decreasing the VAP rate. Given that the monthly decrease in the VAP rate was not considered statistically significant, long-term research needs to be done. Additionally, since this study targeted only nurses, it is suggested that future research targets other health care workers who can influence VAP rates.