• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.1
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• pp.41-47
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• 2002

In this paper, a new line-commutated SCR inverter for renewable power generation system is proposed. The proposed inverter system includes a 6-pulse SCR inverter and an auxiliary circuit. By the proper operation of the auxiliary circuit, the pulse number of the inverter system is increased and the output voltages and currents harmonics are significantly reduced. Analysis, control and simulation for 24-pulse operation of the proposed scheme is Presented and the experimental results from a laboratory Prototype verify the proposed theory.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.177-182
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• 2001

Of two photovoltaic systems such as stand-alone type and utility interactive one, the utility interactive systems are so valuable for power peak-cut particularly in summer season. For the maximum power point tracking(MPPT) by which the generated energy can be maximized, many control methods have been reported up to now. To overcome the disadvantages of the conventional ones, a new MPPT algorithm is proposed which can improve both tracking ability and generating efficiency of photovoltaic system without chopper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.1019-1022
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• 2006

Advances in interactive multimedia and Internet technologies present an array of options that allow the development of very effective training programs. Interactive training is the delivery and management of training using Internet. The trainee actively participates in the training/learning sessions by means of a user-friendly interface that empowers the participant with a sense of control over what they are teaming and the pace at which they are teaming. In this paper, we show process on the development of 3 dimensional e-learing system for Ubiqitous Environment using 3 dimensional supersonic sensor.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.6
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• pp.361-367
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• 2011

In this paper, we propose an interactive embedded system framework for efficient training management in u-health environment. First, we analyzed various requirements of smart training systems for quality of life. We also analyzed the oversea trends and positive effects of the embedded system in terms of both technical and economical factors. Second, we proposed detailed design specification for embedded hardware implementation. Third, we developed effective OS(Operating System) specification for the embedded hardware. Finally, we developed a training scenario and embedded applications such as training control software and analysis software for the smart training systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.109-115
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• 2020

The purpose of this study is to verify influences of a cinema psychotherapy class containing a discussion on improving the emotional intelligence and empathic ability of university students. The research subjects were divided into a test group and a control group, with 106 students in each group. For a semester, the test group attended a practice-centered course including cinema psychotherapy, while the control group attended a discussion on personality psychology theory. The test group was shown 6 films in 12 weeks and answered structural questions between the researcher and subjects, and nonstructural questions between subjects. The results were as follows: The test group showed significant increases in self and other emotion appraisals in the emotional intelligence field. On the other hand, there was no significant change in emotional intelligence among the control group. With respect to empathic ability, the test group showed a significant increase in cognitive empathy, perspective taking, fantasy, and emphatic concern, while the control group didn't show significant change in empathic ability. In post-test, the test group demonstrated a significantly higher ability in cognitive empathy and perspective taking compared to the control group. This study verified that an interactive cinema psychotherapy class can increase emotional intelligence and emphatic ability. This study also demonstrated the effectiveness and necessity of a cinema psychotherapy class. As the class improves, more factors of emotional intelligence and empathic ability can be addressed.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.71-79
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• 2014

This paper discusses a method for the determination of frequency control reserve requirement with consideration of the interaction between ex-ante planning and real-time balancing. In proposed method, we consider the fact that the delivered energy for tertiary control reserve is determined based on required capacity for secondary control reserve and the expected amount of load errors. Uncertain load errors are derived by Brownian motion, an optimization method is suggested using a stochastic programming. In a short, we propose an interactive dependent method for determining secondary control reserve requirement based on the principle that it satisfies to minimize the total cost. As a result, this paper provides will analyze for an example model to demonstrate the capabilities of the method.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.348-356
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• 2019

The backdrivable servovalve is a desirable component for force and interaction control of hydraulic actuation systems because it provides direct force generation mechanical impedance reduction by its own inherent backdrivability. However, high parametric uncertainty and friction effects inside the hydraulic actuation system significantly degrade its advantage. To solve this problem, this letter presents a disturbance-adaptive robust internal-loop compensator (DA-RIC) to generate ideal interactive control performance from the backdrivable-servovalve-based system. The proposed control combines a robust internal-loop compensator structure (RIC) with an explicit disturbance estimator designed for asymptotic disturbance tracking, such that the controlled system provide stable and ideal dynamic behavior for impedance control, while completely compensating the disturbance effects. With the aid of a backdrivable servovalve, we show that the proposed control structure can be implemented based on a simplified nominal model, and the controller enables implementation without accurate knowledge of the target system parameters and disturbances. The performance and properties of the proposed controller are verified by simulation and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.16-19
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• 1994

This paper describes a design method of compensators for decentralized control systems. Decentralized control problem is convenient to design multi-variable control systems and formulated as a series of independent designs. The proposed design method is composed of some steps, which is sequentially to close loop of the system diagonalized by regarding interactive subsystem as perturbation for current loop. So, on the basis of H$_{\infty}$ control theory, decentralized controllers are designed considering robust stability for diagonal systems with perturbations. A numerical example shows that the proposed design method is effective for multivariable control systems..

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.246-253
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• 2013

The Modular Multilevel Converter (MMC) with full bridge cells is available for utility interactive inverter in high voltage line. When it is interconnected with power line, it is possible to control the active power flow in order to supply or charge the power in the line. This research applied the MMC to grid connection system of distributed generator and a power flow control for the MMC is investigated. Theory of power flow between the MMC and the power line is described and control method of power flow and capacitor voltages on arm cells for the MMC are proposed. And effectiveness of the proposed control method is presented by simulation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.92-106
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• 1990

Active compliance is often used in the control of robot manipulators for the implementation of complex tasks such as assembly, multi-finger fine motion, legged-vehicle adaptive control,etc. This technique balances the interactive force between the manipulator tip and its working environment with its position and velocity errors to achieve the operation of a damped spring. This paper investigates the effecft of passive compliance on system stability with regard to force feedback implementation for actively compliant motion. Usually it is understood that accurate position control require a stiff system. However, theoretical examination of control experiments on a legged suspension vehicle suggests that, if the control includes discrete-time force feedback, some passive compliance is necessssary at the legs of the vehicle for system stability. This can be an important factor to bl considered in manipulator design and control. A theoretical analysis, numerical simulation, and experimental result, confirming the above conclusion, are introduced in this paper.