• Journal of the Korean Society of Industry Convergence
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• v.20 no.5
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• pp.419-424
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• 2017

The purpose of this study is to develop a virtual testbed capable of predicting the functional performance of a linear electromagnetic actuator for a high voltage relay in order to reduce its development costs and time. The virtual testbed is defined by a multiphysics coupling approach in order to consider the complex interactions of multi-domains such as the solenoid model of electromagnets, the mass-spring-damper model of mechanical systems, the electric circuit model for an external control unit, and the thermal model for predicting temperature variations. The performances of the existing high voltage relay were estimated by the virtual testbed, and then the effectiveness and validation of the proposed testbed were discussed in comparison with the experimental test results. This study showed that the virtual testbed can be applied in design, optimization, and investigation of high voltage relays.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.22-26
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• 2007

In the fibre to the home (FTTH) era, it is expected that broadband network provisioning will require thousands of optical fibres to be accommodated in a central office for optical access networks. An optical fibre line testing system could be used to reduce maintenance costs and improve service availability depending on the PON's element manager capabilities and the maintenance procedures adopted by the network supplier. When monitoring optical fibres transmitting communication lights, a wavelength of 1625 nm is used for maintenance testing. The splitter installed optical filters allow the communication light to pass but that cut off the test light in the front of optical line terminals (OLTs) and optical network terminals (ONTs). In the economic point of view, We design new planer lightwave circuit splitter embedded filtter and study it optical property.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.593-596
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• 1992

An evaluation method for the effective length of electromagnet - which bas U-shape in frontview and trapezoidal in side view - is presented. Using 2D FEM, 2 analysing models are introduced for calculating effective length of the magnet ; the front model is using the normalized equi-pole face area of the magnet and the side model using the normalized equi-magnetic circuit. The ratio of the effective length to the length of bottom plate (core) comes out 1.25 - 1.30. In addition, 3D FEM analysis has been done and a proto-type test model is manufactured to verify the analysing method. The ratio by the experiment appears 1.2, which is reasonably in good agreement with the suggested numerical results.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.444-447
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• 2004

SNR(Signal to Noise Ratio) is one of the most important performance for the electro-optical camera system. This paper shows not only the SNR analyses for the MSC system, which is the payload in the KOMPSAT2 satellite, but also the trials for its improvement in the electronics circuit design. The MSC deals with one panchromatic band and four multi-spectral bands. The SNR analyses are performed based on the MSC design for the each band and assuming that the defined radiance reached directly to the sensor entrance pupil. In the SNR calculation, shot noise, dark current noise, analog electronics noise and ADC quantization noise are considered as noise sources. In these noise sources, especially, the electronics noise depends on the camera electronics design. This paper shows the camera electronics design to increase SNR and its test results as well as the SNR analyses.

• Progress in Superconductivity and Cryogenics
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• v.13 no.3
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• pp.14-18
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• 2011

Electrical system is changing to smart grid which includes the distributed generations with reusable energy sources in these days. The distributed generations are environmentally friendly and have no concern with depletion problem. But dispatching distributed generations can cause an increase of the fault current. Resistive type super conducting fault current limiter is one of the candidates of solution for the large fault problem in smart grid. In this paper, a design method for the wire length of fault current limiter and the result of short circuit test for small scale modules considering system resistance are introduced.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1145-1148
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• 1999

This paper is introducing a newly developed spark gap switch with dual trigger system, into which the current from the voltage source is injected along wi th the test sequence during the synthetic testing of high voltage circuit-breaker.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.95-95
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• 2010

Because of the environmental matters the importance of the city railroad is as time goes by increasing. The case of obstacle of the power equipment which supplies electric power to city railroad will occur social and economical enormous loss. Thus, I studied on the preventing method in advance which makes it possible for us to maintain facilities efficiently. The main check points of the power facilities are voltage, current, humidity, partial discharge, move current. These points are gathered by sensor and transmitting to data acquisition device. These data are used to check equipment status in real time. In this paper I described in brief test process and results of the detection system.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.434-436
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• 1992

In this paper, we propose a new multilevel nonlinear filter for simultaneous edge detection and noise suppression, which we call a order statistic-median hybrid(OMH) filler. The median-related filters cause an edge shift in the presence of an impulse near the edge. The proposed filter reduces such edge shifting while suppressing impulsive as well as nonimpulsive noise. We show that at the noisy edge point the OMH filter is substantially superior to the median filter, the $\alpha$-TM filter and the STM filter[I] in two respects: (a) the output bias error and (b) the output mean square error. Test results confirm that the OMH filter is robust in preserving sharp edges, inhibiting edge shifting, and suppressing a wide variety of noise. The structure for the OMH filter integrated circuit is also described.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1193-1194
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• 2008

In this paper, we propose application training kit using parallel port circuit of standard architecture in computer system. The proposed training kit is verified through the design of hardware board and a virtual driving test using GUI method in VC++ under window XP operating system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.1
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• pp.25-34
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• 1981

Any logical stuckft faults in multivalued combinational circuits are analyzed using the concept of Boolean difference. The algebra employed is the implementation oriented algebra developed by Allen and Givone. All the lines in the circuit are classified into five types according to their properties. For each type, the equation that represents the complete test set is derived and proved. All the results in examples are confumed to be correct by comparing the truth tables of the normal and faulty circuits.