• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.13-15
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• 2004

In this paper, we propose a novel stability criterion and a guideline of controller design for switched linear systems. Unlike existing criterions such as Lie algebraic method and multiple Lyapunov functions method, the proposed criterion can be applied to each individual system without considering an overall system. By applying the proposed criterion to each individual system separately, a state feedback controller can be easily designed. Stability of the overall system is proved by developing a rule to determine non-increasing Lyapunov functions recursively at each switching instant. An illustrative example is given.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.108-114
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• 2000

In this paper, a new adaptive cross-coupling control(CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

• Journal of Power Electronics
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• v.17 no.4
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• pp.884-891
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• 2017

The improved transfer functions of the modified Sheppard-Taylor (MS-T) converter, which is capable of regulating output voltage under a wide range of input voltage and load variations, negligible current ripple, and fewer components in comparison to the Sheppard-Taylor (S-T) converter, operating in continuous conduction mode (CCM) are investigated in this study. Its DC equilibrium point, small signal model, and transfer functions are derived and analyzed. Then, the voltage controller is applied for this MS-T converter. The comparisons between the derived model and the existing model are presented. The hardware circuit is designed and the circuit experiments are provided for validation. The results show that the improved transfer functions of the MS-T converter are more effective and general than the previous ones for describing its real characteristics.

• Journal of Korea Multimedia Society
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• v.22 no.2
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• pp.178-185
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• 2019

Recently, due to the rapid growth of the internet the existing network architecture is showing limitations. In order to overcome these problems SDN has been proposed as a new paradigm. EIGRP is a modern routing protocol with many advantages but little research has been done on operation in SDN. In this paper we propose a controller-centric EIGRP based on the SDN environment. To construct the SDN network, We seperate the control function and the data transfer function and the EIGRP is operated by a separated controller. Experiments have shown that the proposed scheme can actually work and be used effectively.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.2
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• pp.70-78
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• 2019

CPDLC-DCL (Controller Pilot Data Link Communications-Departure Clearance) began in 2016 with 62 Towers in the United States. The application of this procedure is to utilize equipment different from existing ACARS PDCs or ACARS-DCLs. The purpose of this study is to provide information and understanding of CPDLC-DCL operation methods. Also, B747-8 aircraft considered operational cases related to departure procedures at U.S. airports. This procedure is currently not mandatory but will be mandatory in the future. The Flight Crew Procedures for CPDLC-DCL, as an appendix, will be a useful resource for B747-8 pilots.

• Archives of design research
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• v.20 no.3 s.71
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• pp.235-246
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• 2007

The study aims to design an integrated remote controller, which is an increasingly essential device in the home, for more convenient use. For this purpose, an alternative user interface (UI) design was developed by applying the user interface system of a popular existing product to an integrated remote control highly usable and easy to learn for domestic use, and the usability was evaluated. For the existing popular product, a cellular phone was selected, the operation method of which is similar to the stick-type integrated remote control for which the user interface design was to be developed in this research. Common characteristics of the UI of the selected cellular phone were derived and the characteristics were applied as much as possible to the design of a stick-type integrated remote control. The prototype of the alternative design, which was simulated with Flash, went through two pilot tests for further improvement before making the final experimental prototype. Based on the results, prototype buttons that improved the feeling of use in terms of physical operation and feedback were made, and the usability of the new UI design of a stick-type integrated remote control for domestic use were evaluated with 41 university students in their 20s. According to the results of the experiment, the newly designed stick-type integrated remote control based on the UI of an existing product may improve the usability of remote controls and the outcome of this study is expected to provide a good model for R&D of new UI designs of stick-type integrated remote controls for domestic use.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.611-618
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• 2012

ICAO has recommended the introduction of New CNS/ATM based on GNSS technologies and Data link communication to purpose increasing air traffic demand. The CNS/ATM is composed of communication, Navigation, Surveillance and Air Traffic Management. Cockpit Display Traffic Information(CDTI) that is equipment to share air traffic information to Pilot, Traffic Controller and ground vehicles has been built based on Automatic Dependent Surveillance-Broadcast(ADS-B) information in Surveillance field. This paper is research that what is the effect between pilot and controller through CDTI. Based on ATC communication between Pilot and Controller, We construct simulation environment and did a comparative analysis of it. according to result, We can verify that CDTI makes aircraft Call sign, Position, Altitude information read rate, and notice of air traffic information between Pilot and Controller more improve than ATC environment and Existing Radar System.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2134-2142
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• 2010

IR remote control is the most common way to control home appliances nowadays. Each legacy device is controlled with their own remote controller, and it is not standardized yet. Although it is possible to handle multiple devices with a integrated remote controller, not all the devices and command sets are supported. There are also limitations in expandability especially when new or special command sets are required. In this paper, a efficient zigbee bridge which transforms a command set sent via zigbee to IR comment set is developed. The bridge also has a learning function based on a header comparison method. When a new command is sent, the bridge learn the new code. When a existing code is sent, the bridge dispatches applicable IR command to the appliance. With this approach, it is possible to obtain expandability and flexibility for new commands, and increase the communication efficiency up to 56.8 times.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.38-46
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• 1999

This paper discusses the repetitive tracking control method for a coarse-fine actuator. The proposed system is composed of a magnetic linear drive as a coarse actuator and a piezoelectric linear positioner as a fine actuator. In particular, nonlinear friction in a magnetic linear drive and hysteresis characteristic of a piezoelectric linear positioner are modeled first. The feedback linearization loop uses these models in tracking position control. The control strategy is then further extended to include a repetitive control algorithm in tracking periodic reference inputs. This repetitive controller is implemented on the existing PID controller augmented with feedback linearization loop. The experimental results show that performance in tracking sinusoidal waveforms is noticeably improved by augmenting a PID controller with feedback linearization loop and a repetitive controller together.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.53-62
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• 2010

Recently, various industrial embedded systems including vehicles controlled electronically are evolving to distributed multi-micro controller system. Accordingly, there is a need for standard CAN(Controller Area Network) protocol that ensures high stability and reliability of communication and is simple to construct object-oriented system with high control efficiency. CAN communication interface used general-purpose processor doesn't have many limitations in various application development because of fixed hardware architecture. This paper design and implement a CAN communication interface system based on FPGA. It is verified function and performance of system through monitoring communication with existing AT90CAN128 controller. Implemented CAN communication interface can be reused in development of application systems based on FPGA. And it provides low-cost, small-size and low-power design advantages.