• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.1-8
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• 2014

Heat dissipation of the high power LED is a critical issue. To estimate the junction temperature of the LED chip is most important in characterizing the heat dissipation, but it is impossible to directly measure it. In this study, surface temperatures of the 12.8W LED bulb was measured for 5 points using a data logger and compared with the simulated results using a thermal simulator based on FVM (finite volume method) to secure a reliability of the simulation. Effects of some factors such as lens, emissivity and air inlet were investigated using simulation works and then the results were analysed.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.72-79
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• 2016

In this paper, we propose a Service-adaptive Tactical Data Transmission Protocol (STTS) based on Satellite Communications with narrow bandwidth. STTS is designed to provide additional field for scalability and scheduler for reliability of transport stream protocol based on digital broadcasting standard, DVB-S and DVB-S2. It is also verified the effects of lost data packets with narrow bandwidth through the simulator by traffic model and re-transmission of critical data, and checked the design considerations based on STTS system.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.331-336
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• 2008

In this paper, we propose a real-time people tracking system with multiple CCD cameras for security inside the building. To achieve this goal, we present a method for 3D walking human tracking based on the IMPRESARIO framework incorporating cascaded classifiers into hypothesis evaluation. The efficiency of adaptive selection of cascaded classifiers has been also presented. The camera is mounted from the ceiling of the laboratory so that the image data of the passing people are fully overlapped. The implemented system recognizes people movement along various directions. To track people even when their images are partially overlapped, the proposed system estimates and tracks a bounding box enclosing each person in the tracking region. The approximated convex hull of each individual in the tracking area is obtained to provide more accurate tracking information. We have shown the improvement of reliability for likelihood calculation by using cascaded classifiers. Experimental results show that the proposed method can smoothly and effectively detect and track walking humans through environments such as dense forests.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.233-238
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• 2014

In this paper, we developed a finger robot simulating spasticity and contracture which can be used as a testing bed for evaluating performance of hand rehabilitation devices while it can be also used to train clinicians for improving reliability of clinical assessment. The robot is designed for adult finger size and for independent control of Metacarpophalangeal Joint and Proximal Interphalangeal Joint. Algorithm for mimicking spasticity and contracture is implemented. By adjusting the parameters related to contracture and spasticity, the robot can mimic various patterns of responses observed in fingers with spasticity and contracture.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.35-35
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• 2010

This paper illustrates the use of electric field computation to optimize the design of high voltage composite bushing. In the bushing, a high electric stress occurred between field shaper and central conductor by the closely space. Also coaxial cylindrical shield has a great height along the axis to control an electric field. Consequently, all the potentials are raised axially along the field shaper and electric stress is concentrated on a part of the surface of the FRP tube near the upper end of the field shaper. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing. The optimized design uses internal elements for electric stress grading at critical parts of the bushing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.369-370
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• 2008

This paper describes the electric field distribution of high voltage polymer bushing with inner field shaper designs. The field control can be achieved by means of the designs of such internal field shaper. But high electric stress occurred between field shaper and central conductor by the closely space. In accordance, the floating and ring shield designs was importance for electric stress grading at critical parts of the bushing. The bushing has a central conductor, and internal ring shield or floating shield, gaps are formed between field shaper and ring shield. Accordance equipotential lines extend through gaps. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.332-336
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• 1992

We describe about the graphic simulation system which supports the determination of efficient multi-robot motions during cooperation. For the construction of the simulation software for multi-robot motions, two problems are presented. First problem is that all the robot motions must be determinded using both the desired object motions and the holonomic constraints with the object. To find the robot motions combined with the various object motion path, the robot motions are derived from the desired object path instead of a master robot path. Therefore robot motions can be easily modifiable with the various object motions. This type of motion determination is different from that of the master-slaves method using the master robot motions. The other is that the developments of robot application softwares need a heavy cost when the participated robots or the tasks given to the robots are changed. Based on object-oriented programming paradigm, we present useful software objects describing robot application programming environment. The object-oriented programming paradigm increases the software reusability, reliability, and extensibility, and also provides the structual concepts to cope with the various demands of robot application programming.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.151-154
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• 2000

Used analog control systems have been converted into digital control systems due to performance degradation and difficulty of maintenance. There are few domestic DCS (Distribued Control System)s that have been applied to Bower plant. To apply a demestic DCS to power plant, the reliability, redundacny, and fault tolerance of DCS is important. Besides those items, the control action of control function block is also important. In this paper, we describe the requirements that PID control function block has to have, and implement a PID control function block that satisfies those requirements. Finally. simulation result using digital simulator for boiler system in thermal power plant shows the validity of a implemented PID control function block.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.325-333
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• 2007

A PV system inverter test module using RTDS was developed and performance test of a commercial PV inverter was carried out. The developed module consists of one RTDS hardware rack, RTDS software models representing PV array and simple distribution system, and two power amplifiers that was specifically designed for generating power corresponding to signals from RTDS. Performance test results verified effectiveness and reliability of the test module. It is expected that the developed test module may help PV inverter manufacturers improve ana test their systems in the developing stage.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.1
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• pp.54-60
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• 2006

LCC(Launch Control Center) in NARO space center performs a data monitoring and control through the interface to the external system of launch vehicle. Launch control function needs high reliability and processing speed. Hence, LCS(Launch Control System) is made up a real time system. An important role of the LCS Prototype is discovering a risk element and minimizing it through developing a launch control system. This paper deals with a real time data processing among the simulator, gateway, data distribution server, command and control server which is involving LCS Prototype.