• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.140-145
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• 2001

This paper proposes to use a 20[kHz] phase­shifted Full-Bridge (FB) Zero-Voltage-Switched (ZVS) PWM converter in order to drive a 600[W] magnetron, and analyzes the operational modes in a switching period. Additionally, the controller of the average anode current is designed. Simulation studies and experiments verify that the proposed converter and the average anode current controller shows good performance to drive the magnetron.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1081-1083
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• 2003

The CC's main objective is to manage and control the various operation of the MSC camera. The CC has capability to control the various camera operation modes such as INIT mode, WAIT mode, STANDBY mode, READY IMAGING, DEFAULT READY IMAGING, IBIT and IMAGING mode as well as to manage the interface of the PMU. This paper also shows not only the design concepts in the both of the hardware and the operational software, but also the implementation results for the various CC functions.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.4
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• pp.330-336
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• 1996

An real-time active beacon localization system for mobile robots is developed and implemented. This system permits the estimation of robot positions when detecting light sources by PSD(Position Sensitive Detector) sensor which are placed sparsely over the robots work space as beacons(or landmarks). An LSE(Least Square Estimation) method is introduced to calibrate the internal parameters of a model for the beacon and robot position. The proposed system has two operational modes of position estimation. One is the initial position calculation by the detection of two or more light sources positions of which are known. The other is the continuous position compensation that calculates the position and heading of the robot using the IEKF(Iterated Extended Kalman Filter) applied to the beacon and dead-reckoning data. Practical experiments show that the estimated position obtained by this system is precise enough to be useful for the navigation of robots.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1812-1820
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• 2017

This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.52-56
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• 2009

In this research, we have studied the development of dc-dc converter suitable for the driving of mobile instruments by using a dye-sensitized solar cell(DSC). We also have designed a interlocking circuit. The circuit makes power generation be saved in one battery and concurrently be discharged in the other battery. As this application, mobile devices such as MP3, cellular phone are operated by using power generator from DSC during the daytime and they can be operated by using the saving energy of the daytime during the night. Consequently, it has a simple and robust circuit configuration. Besides, we designed dc-dc converter circuit to drive low power instruments by using NMOS switch and PMOS rectifier. Operational modes are analysed, and then validity of the proposed interface circuit is verified through DCS.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.916-919
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• 1996

An real-time active beacon localization system for mobile robots is developed and implemented. This system permits the estimation of robot positions when detecting light sources by PSD(Position Sensitive Detector) sensor which are placed sparsely over the robot's work space as beacons(or landmarks). An LSE(Least Square Estimation) method is introduced to calibrate the internal parameters of a model for the beacon and robot position. The proposed system has two operational modes of position estimation. One is the initial position calculation by the detection of two or more light sources positions of which are known. The other is the continuous position compensation that calculates the position and heading of the robot using the IEKF(Iterated Extended Kalman Filter) applied to the beacon and dead-reckoning data. Practical experiments show that the estimated position obtained by this system is precise enough to be useful for the navigation of robots.

• Journal of Ocean Engineering and Technology
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• v.13 no.3B
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• pp.116-126
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• 1999

The purpose of this study is to analyze the economic aspect of sea transportation system between Inchon and Youngjong island in which Inchon international airport is being constructed. Total demand of sea transportation arising from in the airport and Yongyu Muwi leisure complex was estimated. To select optimum transportation route, environmental conditions in and around Inchon harbour and Youngjong island including the change of water depth by tide current, fog, rain, wind adn typhoon, ets., were investigated. The preliminary consideration on ships (size, velocity, transport capacity, price), routes, operational modes, terminals and berthing facilities were carried out. The transportation cost per passenger by sea transportation system was estimated to compare with that of land transportation system. It was found that sea transportation system proposed is competitive to the transportation system.

• KIEAE Journal
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• v.7 no.4
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• pp.51-56
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• 2007

This study focuses on developing natural ventilation system which is able to satisfy the good indoor air quality and air speed. The natural ventilation system developed in this study is for double window façade and it has two operation modes for summer and winter. Operational sections of the devices have been analyzed by CFD simulation to calculate discharge coefficients of openings and estimated indoor air speed. For the analysis of the appropriate installation area ratio for each room and the optimum installation area, TRNFLOW simulation has been used. As the results, we could see that the natural ventilation system can provide the similar pollutant removal performance to 0.7 ACH of mechanical ventilation with appropriate installation area and installation area ratio.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.290-293
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• 2008

This paper proposes a criterion to select the modes for modal truncated model of flexible rotor only supported by active magnetic bearings. The proposed approach relies on the concepts of minimum control input and output energy assuming that the system is subjected to transient disturbances. Accurate large order model for the levitated rotor is taken by finite element analysis and transformed to the modal equation. By proposed methodology, which modal states should be retained in the truncated model are investigated over the whole operational speed range by the calculation. Finally, the effectiveness is verified by checking the model error between original model and reduced model.

• Journal of the Korea Institute of Military Science and Technology
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• v.1 no.1
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• pp.65-81
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• 1998

Objective technology development has been carried out aiming performance improvement of the stabilized gun-pointing system for Type-4 tank. The full nonlinear simulation programs with gun bending modes and nonlinearities were developed to estimate, analyze and design the driving and stabilization system, and validated through the comparisons between simulations and test results of the existing Type-1 tank. The prototype is designed, fabricated, tested and evaluated on the test range as well as in the laboratory and followed by development and operational tests. The performance test results on stationary and on-the-move conditions are turned out to be superior to those of the advanced tanks developed in foreign countries.