• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.5
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• pp.376-379
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• 2021

The design and performance of a SiC-MOSFET-based 11-kW bi-directional on-board charger (OBC) for electric vehicles is presented. The OBC consists of a three-phase two-level AC/DC converter and a CLLLC resonant converter. All the power devices are implemented with SiC-MOSFETs to reduce the conduction losses generated in the OBC, and the DC-link voltage is designed to track the level of battery voltage in the forward and reverse powering modes. As a result, the CLLLC resonant converter always runs at the switching frequency near the resonant frequency, resulting in high-efficiency operation at the maximum powering modes. As the DC-link voltage varies according to the battery voltage, the AC/DC converter in the proposed OBC adopts an adaptive DC-link voltage controller. The performance of the proposed 11-kW OBC is verified by a prototype converter with the following specifications: three-phase 60-Hz 380-V input, 11-kW capacity, and battery voltage range of 214-413-V, resulting in the conversion efficiency of over 95.0-% in the forward and reverse powering modes.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.886-893
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• 2018

U.S. and the allies attacked chemical weapons sites in Syria in 2018, and verbal battles are carried out about the effectiveness of the air strike. Syria claimed 13 missiles were shot down, and Russia claimed 71 missiles were shot down while the U.S. released pictures of completely destroyed targets, only. It led controversy about the effectiveness of missile defense system. If there is a method to observe mission success rate of the air strike, it can not only improve combat awareness but also can be a good sales strategy in military industry. This paper describes effects and considerations of a Weapon Data Link(WDL) technology which can be used as a smoking gun of effectiveness. The paper describes WDL abilities such as In-Flight Track Update, Loiter, and Bomb Hit Indication etc., and presents examples of expected effectiveness of the WDL. In addition, this paper briefly summarizes operational consideration for better performance.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.11
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• pp.31-35
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• 1992

This paper presents a decentralized adaptive controller design for a robot manipulator to track the given desired trajectory in the joint space. The controller is of distributed structure and does not require the complex manipulator dynamic model, thereby it is computationally very efficient. Each joint is independently controlled by a PID feedback part and a velocity-acceleration feedforward part. Simulation results for a two-link direct drive manipulator conform that the proposed decentralized scheme is feasible.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.895-901
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• 1993

This paper present controller designs based on the configuration control framework for a redundant manipulator to accomplish the basic task of desired, end-effector motion, while utilizing the redundancy to achieve the additional tasks such as joint motion control, obstacle avoidance, singularity avoidance. etc. A task based decentralized adaptive scheme is then applied for the configuration variables to track some reference trajectories as close as possible. Simulation results for a direct-drive three-link arm in the vertical plane demonstrate its capabilities for performing various useful tasks.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.32-35
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• 1987

An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a desired trajectory in spite of the presence of nonlinearties and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which combines the pole placement with the extended linearized perturbation model. And this control scheme has two components: a feadforward control and a feedback compensation control. Based on this, the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.418-423
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• 2003

Many countries in Asia have been researching for linking and activation of Asia transverse railway and we are trying to link Trans-Korean railway and Transcontinental railway. However we are confronted with a difficult question that the railway system of each country is different from each other-gauge, track formation and signal system. These problems will obstruct prior occupation of market because of loss of time and cost for trans vehicles and transshipment. In this paper, we tried to setting up development direction of Korean variable gauge vehicles by examine international development direction of variable gauge vehicles.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.655-662
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• 1988

An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a deired trajectory in spite of the presence of nonlinearies and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which controls the extended linearized perturbaton model via the pole placement, and this control. The feasibility of the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.19-30
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• 2005

The objective of this research is to keep track of path travel time using methods of collecting traffic data. Users of traffic information are looking for extensive information on path travel time, which is referred to as the time taken for traveling from the origin to the destination. However, all the information available is the average path travel times, which is a simple sum of the average link travel times. The average path travel time services are not up to the expectation of traffic information consumers. To improve provide more accurate path travel time services, this research makes a number of different estimates of various path travel times on one path, assuming it will be under the same condition, and provides a range of estimates with their probabilities to the consumers, who are looking for detailed information. To estimate the distribution of the path travel times as a combination of link travel times. this research analyzes the relation between the link travel time and path travel time. Based on the result of the estimation. this research develops the algorithm that combines the distribution of link travel time and estimates the path travel time based on the link travel times. This algorithm was tested and proven to be highly reliable for estimating the path traffic time.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.199-208
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• 2010

Positions of tactical objects are represented as Time, Space and Position Information(TSPI) in modeling and simulations(M&S). The format and required information record for TSPI is investigated by referring the TSPI object model of the Test and Training Enabling Architecture(TENA), which has been developed by the United States Department of Defense. The most sophisticated tactical data link, Link-16 has a Precise Participant Location and Information (PPLI) message. We study the data format for exchanging TSPI data based on the PPLI message. To evaluate and track positions of tactical objects, we consider the Kalman filter for linear systems, and the extended Kalman filter and the unscented Kalman filter for nonlinear systems. Based on motion equations of a ballistic missile, the tracking performance for the trajectory of the ballistic missile is simulated by the unscented Kalman filter.

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.175-183
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• 2008

Wi-Fi defines the procedure to search an AP, authenticate both station and AP, and associate the new BSS or ESS which enables the link layer handoff. One of the problems for hotspot service of Wi-Fi is "passing-object", Wi-Fi describes the messages exchanges between two neighboring APs in BSS or ESS. If the station passes through the neighboring APs before completing link-layer handoff, the path where the tunneled packets should be sent is lost. In this paper, we propose to integrate the positioning entity in a service domain to keep track the high-speed movement.