• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.91-93
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• 2008

A Buoyant Hybrid Power Generation System (BHPGS) described in this paper, is a conceptual approach to a hybrid solar-wind power generation in the near sea. The primary purpose of the BHPGS is given to improve utilization of solar cell modules. Main components of the BHPGS include a solar cell module, buoyant object, power generator, and support assembly including weight. Components such a generator controller, DC/AC converter, etc., are not configured in the current BHPGS because they can easily be purchased as a commercial-off-the-shelf product. In addition, some of the BHPGS applications are discussed.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.5
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• pp.41-50
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• 1995

Single-phase induction motors are widely used in many light duty applications, especially in home and office. many applications which use these motors require adjustable speed control continuously. In general, the speed control of single-phase induction motor is accomplished at a few discrete speeds by using tapped-windings, pole switching or gear. These techniques are inefficient and complicated. In this paper, Torque controller which adjusts a generating torque using phase difference between main winding voltage and auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage phase angle and torque. Simulation results of the torque-speed characteristics using the controlled auxiliary winding supply are shown and discussed. and the drive is tested experimentally to verify the results of the theory by using a dynamometer.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.4
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• pp.215-219
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• 2005

This paper aims at asymptotic stabilization for uncertain dynamic systems with state and input delays. We propose a memoryless state feedback controller which maximizes the delay bound for guaranteeing stability of the system. Using Lyapunov method and linear matrix inequality (LMI) approach, a delay-dependent stabilization criterion is devised by taking the relationship between the terms in the Leibniz-Newton formula into account. The criterion is represented in terms of LMIs, which can be solved by various efficient convex optimization algorithms. Numerical examples are given to illustrate our main method.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.338-341
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• 2001

This paper describes on the development of power monitoring system using microprocessor. The detecting power system is composed of main controller system and analyzing software. The system detected voltage, current temperature, leakage current and its saved in ROM. This system applies the 'AT89C52' to CPU and 'AM29F040B' used a memory to save the data.

• Journal of the Korean Institute of Intelligent Systems
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• v.2 no.3
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• pp.29-39
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• 1992

We investigate a systematic design procedure of automatic rule generation of fuzzy logic based controllers for highly nonlinear dynamic systems such as an engine dynamic modle. By "automatic rule generation" we mean autonomous clustering or collection of such meaningful transitional relations from one conditional subspace to another. During the design procedure, we also consider optimaly control strategies such as minimum squared error, near minimum time, minimum energy or combined performance critiera. Fuzzy feedback control systems designed by our method have the properties of closed-loop stability, robustness under parameter variabitions, and a certain degree of optimality. Most of all, the main advantage of the proposed approach is that reliability can be potentially increased even if a large grain of uncertainty is involved within the control system under consideration. A numerical example is shown in which we apply our strategic fuzzy controller dwsign to a highly nonlinear model of engine idling speed control.d control.

• Journal of the Semiconductor & Display Technology
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• v.4 no.3 s.12
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• pp.23-27
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• 2005

The effects of the base vacuum level on a plasma display panel (PDP) produced by the vacuum in-line sealing technology were investigated. The main equipment of the vacuum in-line sealing process consists of the sealing chamber, pumping systems for evacuating, mass flow controller for introducing the plasma gases, and other measuring systems. During the sealing process, the impurity gases were fully evacuated and the panel was prevented from the adsorption of impurity gases. As a result, the brightness increased as the impurity gas density decreased, so we found that the vacuum in-line sealing process was more efficient technology an the conventional sealing process.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.117-124
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• 2006

In this paper, we develope the navigation system for patrol robots in indoor environment. The proposed system consists of PDA map modelling, a localization algorithm based on a global position sensor and an automatic charging station. For the practical use in security system, the PDA is used to build object map on the given indoor map. And the builded map is downloaded to the mobile robot and used in path planning. The global path planning is performed with a localization sensor and the downloaded map. As a main controller, we use PXA270 based hardware platform in which embedded linux 2.6 is developed. Data handling for various sensors and the localization algorithm are performed in the linux platform. Also, we implemented a local path planning algorithm for object avoidance with ultra sonar sensors. Finally, for the automatic charging, we use an infrared ray system and develop a docking algorithm. The navigation system is experimented with the two-wheeled mobile robot using North-Star localization system.

• Korean Journal of Computational Design and Engineering
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• v.14 no.1
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• pp.50-59
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• 2009

There are two main problems in the current PLC ladder programming practices: First, currently there are no widely adopted systematic design methods to deal with PLC based control systems in the shop floor. So, the control logic design phase is usually omitted in current PLC programming development life cycle. Second, PLC ladder logic provides only microscopic view of system processes. As a result, it is difficult for FA engineers to have overall perspectives about the interaction of system components intuitively during the verification step of logic errors. To solve these problems, this paper proposed object-oriented design and automatic generation method of PLC ladder logic. Based on the proposed method, the computer software to assist the automatic ladder logic generation is also developed.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.03a
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• pp.61-66
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• 1998

Since a gas turbine is made use of generating electricity for peak time, it is a very important to operate a peak time load with safety. The main components of a gas turbine are the compressor, the combustion chamber and the turbine. So, there also must be modeled a component of gas turbines for the control with safety but it is not easy. In this paper we acquire a transfer function based on the operations data of Gun-san gas turbine and study to apply Neural-Network 2-DOF PID controler to control loop of gas turbine to reduce phenomena caused by integral and derivative actions through simulation. We obtained satisfactory results to disturbances of subcontrol loop such as, fuel flow, air flow, turbine extraction temperature.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.5 no.1
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• pp.46-52
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• 2002

A robust nonlinear observer, utilizing the sliding mode concept, is developed for the dynamic positioning of ships. The observer provides the estimates of linear velocities of the ship and bias from slowly varying environmental loads. It also filters out wave frequency motion to avoid wear of actuators and excessive fuel consumption. The main advantage of the proposed observer is in its robustness. Especially, the observer structure with a saturation function makes the proposed observer robust against neglected nonlinearties, disturbances and uncertainties. Since the mathematical model of DP ships is difficult to obtain and includes uncertainties and disturbances, it is very important for the observer to be robust. A nonlinear output feedback controller is derives based on the developed observer using the observer backstepping technique, and the global stability of the observer and control law is shown by Lyapunov stability theory.. A set of simulation was carried out to investigate the performance of the proposed observer for dynamic positioning of ships.